[GitHub] [nuttx] shuai532209720 opened a new pull request, #8103: feat: add mipidsi support

[GitBox <gi...@apache.org>]

shuai532209720 opened a new pull request, #8103:
URL: https://github.com/apache/nuttx/pull/8103

   add mipi dsi subsystem support.
   
   reference links:
   https://github.com/torvalds/linux/blob/master/drivers/gpu/drm/drm_mipi_dsi.c https://github.com/torvalds/linux/blob/master/include/video/mipi_display.h
   
   Signed-off-by: liushuai25 <li...@xiaomi.com>
   
   ## Summary
   Add mipi dsi subsystem.
   Decouple panel driver and chip dsi driver.
   ## Impact
   
   ## Testing
   
   


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[GitHub] [nuttx] xiaoxiang781216 merged pull request #8103: feat: add mipidsi support

[GitBox <gi...@apache.org>]

xiaoxiang781216 merged PR #8103:
URL: https://github.com/apache/nuttx/pull/8103


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[GitHub] [nuttx] pkarashchenko commented on a diff in pull request #8103: feat: add mipidsi support

[GitBox <gi...@apache.org>]

pkarashchenko commented on code in PR #8103:
URL: https://github.com/apache/nuttx/pull/8103#discussion_r1069116924


##########
drivers/video/mipidsi/mipi_dsi_device.c:
##########
@@ -0,0 +1,1023 @@
+/****************************************************************************
+ * drivers/video/mipidsi/mipi_dsi_device.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <assert.h>
+#include <debug.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <nuttx/video/mipi_display.h>
+#include <nuttx/kmalloc.h>
+
+#include "mipi_dsi.h"
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mipi_dsi_transfer
+ *
+ * Description:
+ *   Transfer message to display modules
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *   msg - Message to transfer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transfered or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_transfer(FAR struct mipi_dsi_device *device,
+                          FAR struct mipi_dsi_msg *msg)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->transfer == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_LPM)

Review Comment:
   minor
   ```suggestion
     if ((device->mode_flags & MIPI_DSI_MODE_LPM) != 0)
   ```



##########
drivers/video/mipidsi/mipi_dsi_device.c:
##########
@@ -0,0 +1,1023 @@
+/****************************************************************************
+ * drivers/video/mipidsi/mipi_dsi_device.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <assert.h>
+#include <debug.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <nuttx/video/mipi_display.h>
+#include <nuttx/kmalloc.h>
+
+#include "mipi_dsi.h"
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mipi_dsi_transfer
+ *
+ * Description:
+ *   Transfer message to display modules
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *   msg - Message to transfer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transfered or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_transfer(FAR struct mipi_dsi_device *device,
+                          FAR struct mipi_dsi_msg *msg)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->transfer == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_LPM)
+    {
+      msg->flags |= MIPI_DSI_MSG_USE_LPM;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_AFTER_FRAME)

Review Comment:
   minor
   ```suggestion
     if ((device->mode_flags & MIPI_DSI_MODE_AFTER_FRAME) != 0)
   ```



##########
drivers/video/mipidsi/mipi_dsi_device.c:
##########
@@ -0,0 +1,1023 @@
+/****************************************************************************
+ * drivers/video/mipidsi/mipi_dsi_device.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <assert.h>
+#include <debug.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <nuttx/video/mipi_display.h>
+#include <nuttx/kmalloc.h>
+
+#include "mipi_dsi.h"
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mipi_dsi_transfer
+ *
+ * Description:
+ *   Transfer message to display modules
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *   msg - Message to transfer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transfered or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_transfer(FAR struct mipi_dsi_device *device,
+                          FAR struct mipi_dsi_msg *msg)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->transfer == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_LPM)
+    {
+      msg->flags |= MIPI_DSI_MSG_USE_LPM;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_AFTER_FRAME)
+    {
+      msg->flags |= MIPI_DSI_MSG_AFTER_FRAME;
+    }
+
+  return ops->transfer(device->host, msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_attach
+ *
+ * Description:
+ *   Attach a DSI device to its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_attach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->attach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->attach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_detach
+ *
+ * Description:
+ *   Detach a DSI device from its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_detach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->detach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->detach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_shutdown_peripheral
+ *
+ * Description:
+ *   Send a Shutdown Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_shutdown_peripheral(FAR struct mipi_dsi_device *device)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SHUTDOWN_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,

Review Comment:
   can we use C89 compatible initializer?



##########
drivers/video/mipidsi/mipi_dsi_device.c:
##########
@@ -0,0 +1,1023 @@
+/****************************************************************************
+ * drivers/video/mipidsi/mipi_dsi_device.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <assert.h>
+#include <debug.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <nuttx/video/mipi_display.h>
+#include <nuttx/kmalloc.h>
+
+#include "mipi_dsi.h"
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mipi_dsi_transfer
+ *
+ * Description:
+ *   Transfer message to display modules
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *   msg - Message to transfer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transfered or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_transfer(FAR struct mipi_dsi_device *device,
+                          FAR struct mipi_dsi_msg *msg)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->transfer == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_LPM)
+    {
+      msg->flags |= MIPI_DSI_MSG_USE_LPM;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_AFTER_FRAME)
+    {
+      msg->flags |= MIPI_DSI_MSG_AFTER_FRAME;
+    }
+
+  return ops->transfer(device->host, msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_attach
+ *
+ * Description:
+ *   Attach a DSI device to its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_attach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->attach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->attach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_detach
+ *
+ * Description:
+ *   Detach a DSI device from its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_detach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->detach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->detach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_shutdown_peripheral
+ *
+ * Description:
+ *   Send a Shutdown Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_shutdown_peripheral(FAR struct mipi_dsi_device *device)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SHUTDOWN_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  int ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_turn_on_peripheral
+ *
+ * Description:
+ *   Send a Turn On Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_turn_on_peripheral(FAR struct mipi_dsi_device *device)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_TURN_ON_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,

Review Comment:
   ditto



##########
drivers/video/mipidsi/mipi_dsi_device.c:
##########
@@ -0,0 +1,1023 @@
+/****************************************************************************
+ * drivers/video/mipidsi/mipi_dsi_device.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <assert.h>
+#include <debug.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <nuttx/video/mipi_display.h>
+#include <nuttx/kmalloc.h>
+
+#include "mipi_dsi.h"
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mipi_dsi_transfer
+ *
+ * Description:
+ *   Transfer message to display modules
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *   msg - Message to transfer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transfered or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_transfer(FAR struct mipi_dsi_device *device,
+                          FAR struct mipi_dsi_msg *msg)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->transfer == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_LPM)
+    {
+      msg->flags |= MIPI_DSI_MSG_USE_LPM;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_AFTER_FRAME)
+    {
+      msg->flags |= MIPI_DSI_MSG_AFTER_FRAME;
+    }
+
+  return ops->transfer(device->host, msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_attach
+ *
+ * Description:
+ *   Attach a DSI device to its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_attach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->attach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->attach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_detach
+ *
+ * Description:
+ *   Detach a DSI device from its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_detach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->detach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->detach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_shutdown_peripheral
+ *
+ * Description:
+ *   Send a Shutdown Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_shutdown_peripheral(FAR struct mipi_dsi_device *device)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SHUTDOWN_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  int ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_turn_on_peripheral
+ *
+ * Description:
+ *   Send a Turn On Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_turn_on_peripheral(FAR struct mipi_dsi_device *device)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_TURN_ON_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_set_maximum_return_packet_size
+ *
+ * Description:
+ *   Specify the maximum size of the payload in a long packet transmitted
+ *   from the peripheral back to the device host processor
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   value - The maximum size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_set_maximum_return_packet_size(
+                          FAR struct mipi_dsi_device *device, uint16_t value)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { value & 0xff, value >> 8 },
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_compression_mode
+ *
+ * Description:
+ *   Enable / disable DSC on the peripheral. Enable or disable Display Stream
+ *   Compression on the peripheral using the default Picture Parameter Set
+ *   and VESA DSC 1.1 algorithm.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   enable - Whether to enable or disable the DSC
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_compression_mode(FAR struct mipi_dsi_device *device,
+                              bool enable)
+{
+  /* Note: Needs updating for non-default PPS or algorithm */
+
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_COMPRESSION_MODE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { enable & 0xff, 0 },
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_generic_write
+ *
+ * Description:
+ *   Transmit data using a generic write packet
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   payload - buffer containing the payload
+ *   size - size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_generic_write(FAR struct mipi_dsi_device *device,
+                           FAR const void *payload,
+                           size_t size)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_buf = payload,
+    .tx_len = size
+  };
+
+  switch (size)
+    {
+    case 0:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM;
+      break;
+
+    case 1:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM;
+      break;
+
+    case 2:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM;
+      break;
+
+    default:
+      msg.type = MIPI_DSI_LONG_GENERIC_WRITE;
+      break;
+    }
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_generic_read
+ *
+ * Description:
+ *   Receive data using a generic read packet.
+ *   This function will automatically choose the right data type depending on
+ *   the number of parameters passed in.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   params - buffer containing the request parameters
+ *   num_params - number of request parameters
+ *   data - buffer in which to return the received data
+ *   size - size of receive buffer
+ *
+ * Returned Value:
+ *   The number of bytes successfully read or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_generic_read(FAR struct mipi_dsi_device *device,
+                              FAR const void *params,
+                              size_t num_params,
+                              FAR void *data,
+                              size_t size)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_len = num_params,
+    .tx_buf = params,
+    .rx_len = size,

Review Comment:
   ditto



##########
drivers/video/mipidsi/mipi_dsi_device.c:
##########
@@ -0,0 +1,1023 @@
+/****************************************************************************
+ * drivers/video/mipidsi/mipi_dsi_device.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <assert.h>
+#include <debug.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <nuttx/video/mipi_display.h>
+#include <nuttx/kmalloc.h>
+
+#include "mipi_dsi.h"
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mipi_dsi_transfer
+ *
+ * Description:
+ *   Transfer message to display modules
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *   msg - Message to transfer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transfered or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_transfer(FAR struct mipi_dsi_device *device,
+                          FAR struct mipi_dsi_msg *msg)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->transfer == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_LPM)
+    {
+      msg->flags |= MIPI_DSI_MSG_USE_LPM;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_AFTER_FRAME)
+    {
+      msg->flags |= MIPI_DSI_MSG_AFTER_FRAME;
+    }
+
+  return ops->transfer(device->host, msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_attach
+ *
+ * Description:
+ *   Attach a DSI device to its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_attach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->attach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->attach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_detach
+ *
+ * Description:
+ *   Detach a DSI device from its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_detach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->detach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->detach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_shutdown_peripheral
+ *
+ * Description:
+ *   Send a Shutdown Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_shutdown_peripheral(FAR struct mipi_dsi_device *device)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SHUTDOWN_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  int ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_turn_on_peripheral
+ *
+ * Description:
+ *   Send a Turn On Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_turn_on_peripheral(FAR struct mipi_dsi_device *device)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_TURN_ON_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_set_maximum_return_packet_size
+ *
+ * Description:
+ *   Specify the maximum size of the payload in a long packet transmitted
+ *   from the peripheral back to the device host processor
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   value - The maximum size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_set_maximum_return_packet_size(
+                          FAR struct mipi_dsi_device *device, uint16_t value)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { value & 0xff, value >> 8 },
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_compression_mode
+ *
+ * Description:
+ *   Enable / disable DSC on the peripheral. Enable or disable Display Stream
+ *   Compression on the peripheral using the default Picture Parameter Set
+ *   and VESA DSC 1.1 algorithm.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   enable - Whether to enable or disable the DSC
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_compression_mode(FAR struct mipi_dsi_device *device,
+                              bool enable)
+{
+  /* Note: Needs updating for non-default PPS or algorithm */
+
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_COMPRESSION_MODE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { enable & 0xff, 0 },

Review Comment:
   ditto



##########
drivers/video/mipidsi/mipi_dsi_device.c:
##########
@@ -0,0 +1,1023 @@
+/****************************************************************************
+ * drivers/video/mipidsi/mipi_dsi_device.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <assert.h>
+#include <debug.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <nuttx/video/mipi_display.h>
+#include <nuttx/kmalloc.h>
+
+#include "mipi_dsi.h"
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mipi_dsi_transfer
+ *
+ * Description:
+ *   Transfer message to display modules
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *   msg - Message to transfer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transfered or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_transfer(FAR struct mipi_dsi_device *device,
+                          FAR struct mipi_dsi_msg *msg)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->transfer == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_LPM)
+    {
+      msg->flags |= MIPI_DSI_MSG_USE_LPM;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_AFTER_FRAME)
+    {
+      msg->flags |= MIPI_DSI_MSG_AFTER_FRAME;
+    }
+
+  return ops->transfer(device->host, msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_attach
+ *
+ * Description:
+ *   Attach a DSI device to its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_attach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->attach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->attach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_detach
+ *
+ * Description:
+ *   Detach a DSI device from its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_detach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->detach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->detach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_shutdown_peripheral
+ *
+ * Description:
+ *   Send a Shutdown Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_shutdown_peripheral(FAR struct mipi_dsi_device *device)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SHUTDOWN_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  int ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_turn_on_peripheral
+ *
+ * Description:
+ *   Send a Turn On Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_turn_on_peripheral(FAR struct mipi_dsi_device *device)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_TURN_ON_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_set_maximum_return_packet_size
+ *
+ * Description:
+ *   Specify the maximum size of the payload in a long packet transmitted
+ *   from the peripheral back to the device host processor
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   value - The maximum size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_set_maximum_return_packet_size(
+                          FAR struct mipi_dsi_device *device, uint16_t value)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { value & 0xff, value >> 8 },
+  };

Review Comment:
   ditto



##########
drivers/video/mipidsi/mipi_dsi_device.c:
##########
@@ -0,0 +1,1023 @@
+/****************************************************************************
+ * drivers/video/mipidsi/mipi_dsi_device.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <assert.h>
+#include <debug.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <nuttx/video/mipi_display.h>
+#include <nuttx/kmalloc.h>
+
+#include "mipi_dsi.h"
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mipi_dsi_transfer
+ *
+ * Description:
+ *   Transfer message to display modules
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *   msg - Message to transfer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transfered or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_transfer(FAR struct mipi_dsi_device *device,
+                          FAR struct mipi_dsi_msg *msg)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->transfer == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_LPM)
+    {
+      msg->flags |= MIPI_DSI_MSG_USE_LPM;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_AFTER_FRAME)
+    {
+      msg->flags |= MIPI_DSI_MSG_AFTER_FRAME;
+    }
+
+  return ops->transfer(device->host, msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_attach
+ *
+ * Description:
+ *   Attach a DSI device to its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_attach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->attach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->attach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_detach
+ *
+ * Description:
+ *   Detach a DSI device from its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_detach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->detach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->detach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_shutdown_peripheral
+ *
+ * Description:
+ *   Send a Shutdown Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_shutdown_peripheral(FAR struct mipi_dsi_device *device)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SHUTDOWN_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  int ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_turn_on_peripheral
+ *
+ * Description:
+ *   Send a Turn On Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_turn_on_peripheral(FAR struct mipi_dsi_device *device)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_TURN_ON_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_set_maximum_return_packet_size
+ *
+ * Description:
+ *   Specify the maximum size of the payload in a long packet transmitted
+ *   from the peripheral back to the device host processor
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   value - The maximum size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_set_maximum_return_packet_size(
+                          FAR struct mipi_dsi_device *device, uint16_t value)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { value & 0xff, value >> 8 },
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_compression_mode
+ *
+ * Description:
+ *   Enable / disable DSC on the peripheral. Enable or disable Display Stream
+ *   Compression on the peripheral using the default Picture Parameter Set
+ *   and VESA DSC 1.1 algorithm.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   enable - Whether to enable or disable the DSC
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_compression_mode(FAR struct mipi_dsi_device *device,
+                              bool enable)
+{
+  /* Note: Needs updating for non-default PPS or algorithm */
+
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_COMPRESSION_MODE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { enable & 0xff, 0 },
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_generic_write
+ *
+ * Description:
+ *   Transmit data using a generic write packet
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   payload - buffer containing the payload
+ *   size - size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_generic_write(FAR struct mipi_dsi_device *device,
+                           FAR const void *payload,
+                           size_t size)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_buf = payload,
+    .tx_len = size
+  };
+
+  switch (size)
+    {
+    case 0:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM;
+      break;
+
+    case 1:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM;
+      break;
+
+    case 2:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM;
+      break;
+
+    default:
+      msg.type = MIPI_DSI_LONG_GENERIC_WRITE;
+      break;
+    }
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_generic_read
+ *
+ * Description:
+ *   Receive data using a generic read packet.
+ *   This function will automatically choose the right data type depending on
+ *   the number of parameters passed in.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   params - buffer containing the request parameters
+ *   num_params - number of request parameters
+ *   data - buffer in which to return the received data
+ *   size - size of receive buffer
+ *
+ * Returned Value:
+ *   The number of bytes successfully read or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_generic_read(FAR struct mipi_dsi_device *device,
+                              FAR const void *params,
+                              size_t num_params,
+                              FAR void *data,
+                              size_t size)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_len = num_params,
+    .tx_buf = params,
+    .rx_len = size,
+    .rx_buf = data
+  };
+
+  switch (num_params)
+    {
+    case 0:
+      msg.type = MIPI_DSI_GENERIC_READ_0_PARAM;
+      break;
+    case 1:
+      msg.type = MIPI_DSI_GENERIC_READ_1_PARAM;
+      break;
+    case 2:
+      msg.type = MIPI_DSI_GENERIC_READ_2_PARAM;
+      break;
+    default:
+      return -EINVAL;
+    }
+
+  return mipi_dsi_transfer(device, &msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_dcs_write_buffer
+ *
+ * Description:
+ *   Transmit a DCS command with payload.
+ *   This function will automatically choose the right data type depending on
+ *   the command payload length.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   data - buffer containing data to be transmitted
+ *   len - size of transmission buffer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transmitted or a negative error
+ *   code on failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_dcs_write_buffer(FAR struct mipi_dsi_device *device,
+                                  FAR const void *data,
+                                  size_t len)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_buf = data,
+    .tx_len = len
+  };
+
+  switch (len)
+    {
+    case 0:
+      return -EINVAL;
+    case 1:
+      msg.type = MIPI_DSI_DCS_SHORT_WRITE_0_PARAM;
+      break;
+    case 2:
+      msg.type = MIPI_DSI_DCS_SHORT_WRITE_1_PARAM;
+      break;
+    default:
+      msg.type = MIPI_DSI_DCS_LONG_WRITE;
+      break;

Review Comment:
   ```suggestion
         case 0:
           return -EINVAL;
         case 1:
           msg.type = MIPI_DSI_DCS_SHORT_WRITE_0_PARAM;
           break;
         case 2:
           msg.type = MIPI_DSI_DCS_SHORT_WRITE_1_PARAM;
           break;
         default:
           msg.type = MIPI_DSI_DCS_LONG_WRITE;
           break;
   ```



##########
drivers/video/mipidsi/mipi_dsi_device.c:
##########
@@ -0,0 +1,1023 @@
+/****************************************************************************
+ * drivers/video/mipidsi/mipi_dsi_device.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <assert.h>
+#include <debug.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <nuttx/video/mipi_display.h>
+#include <nuttx/kmalloc.h>
+
+#include "mipi_dsi.h"
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mipi_dsi_transfer
+ *
+ * Description:
+ *   Transfer message to display modules
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *   msg - Message to transfer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transfered or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_transfer(FAR struct mipi_dsi_device *device,
+                          FAR struct mipi_dsi_msg *msg)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->transfer == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_LPM)
+    {
+      msg->flags |= MIPI_DSI_MSG_USE_LPM;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_AFTER_FRAME)
+    {
+      msg->flags |= MIPI_DSI_MSG_AFTER_FRAME;
+    }
+
+  return ops->transfer(device->host, msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_attach
+ *
+ * Description:
+ *   Attach a DSI device to its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_attach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->attach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->attach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_detach
+ *
+ * Description:
+ *   Detach a DSI device from its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_detach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->detach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->detach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_shutdown_peripheral
+ *
+ * Description:
+ *   Send a Shutdown Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_shutdown_peripheral(FAR struct mipi_dsi_device *device)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SHUTDOWN_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  int ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_turn_on_peripheral
+ *
+ * Description:
+ *   Send a Turn On Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_turn_on_peripheral(FAR struct mipi_dsi_device *device)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_TURN_ON_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_set_maximum_return_packet_size
+ *
+ * Description:
+ *   Specify the maximum size of the payload in a long packet transmitted
+ *   from the peripheral back to the device host processor
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   value - The maximum size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_set_maximum_return_packet_size(
+                          FAR struct mipi_dsi_device *device, uint16_t value)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { value & 0xff, value >> 8 },
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_compression_mode
+ *
+ * Description:
+ *   Enable / disable DSC on the peripheral. Enable or disable Display Stream
+ *   Compression on the peripheral using the default Picture Parameter Set
+ *   and VESA DSC 1.1 algorithm.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   enable - Whether to enable or disable the DSC
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_compression_mode(FAR struct mipi_dsi_device *device,
+                              bool enable)
+{
+  /* Note: Needs updating for non-default PPS or algorithm */
+
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_COMPRESSION_MODE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { enable & 0xff, 0 },
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_generic_write
+ *
+ * Description:
+ *   Transmit data using a generic write packet
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   payload - buffer containing the payload
+ *   size - size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_generic_write(FAR struct mipi_dsi_device *device,
+                           FAR const void *payload,
+                           size_t size)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_buf = payload,
+    .tx_len = size
+  };
+
+  switch (size)
+    {
+    case 0:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM;
+      break;
+
+    case 1:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM;
+      break;
+
+    case 2:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM;
+      break;
+
+    default:
+      msg.type = MIPI_DSI_LONG_GENERIC_WRITE;
+      break;
+    }

Review Comment:
   ```suggestion
     switch (size)
       {
         case 0:
           msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM;
           break;
   
         case 1:
           msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM;
           break;
   
         case 2:
           msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM;
           break;
   
         default:
           msg.type = MIPI_DSI_LONG_GENERIC_WRITE;
           break;
       }
   ```



##########
drivers/video/mipidsi/mipi_dsi_host.c:
##########
@@ -0,0 +1,165 @@
+/****************************************************************************
+ * drivers/video/mipidsi/mipi_dsi_host.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <debug.h>
+
+#include <nuttx/kmalloc.h>
+
+#include "mipi_dsi.h"
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+struct mipi_dsi_hosts_s
+{
+  int count;
+  struct mipi_dsi_host *hosts[0];

Review Comment:
   C89 incompatible.
   Maybe `struct mipi_dsi_host *hosts[1];` can be used?



##########
drivers/video/mipidsi/mipi_dsi_packet.c:
##########
@@ -0,0 +1,220 @@
+/****************************************************************************
+ * drivers/video/mipidsi/mipi_dsi_packet.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <assert.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <string.h>
+
+#include <nuttx/video/mipi_dsi.h>
+#include <nuttx/video/mipi_display.h>
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mipi_dsi_pixel_format_to_bpp
+ *
+ * Description:
+ *   Obtain the number of bits per pixel for any given pixel format defined
+ *   by the MIPI DSI specification
+ *
+ * Input Parameters:
+ *   fmt - MIPI DSI pixel format
+ *
+ * Returned Value:
+ *   The number of bits per pixel of the given pixel format.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_pixel_format_to_bpp(uint8_t fmt)
+{
+  switch (fmt)
+    {
+    case MIPI_DSI_FMT_RGB888:
+    case MIPI_DSI_FMT_RGB666:
+      return 24;
+    case MIPI_DSI_FMT_RGB666_PACKED:
+      return 18;
+    case MIPI_DSI_FMT_RGB565:
+      return 16;
+    }
+
+  return -EINVAL;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_packet_format_is_short
+ *
+ * Description:
+ *   Check if a packet is of the short format
+ *
+ * Input Parameters:
+ *   type - MIPI DSI data type of the packet
+ *
+ * Returned Value:
+ *   True if the packet for the given data type is a short packet, false
+ *   otherwise.
+ *
+ ****************************************************************************/
+
+bool mipi_dsi_packet_format_is_short(uint8_t type)
+{
+  switch (type)
+    {
+    case MIPI_DSI_VSYNC_START:
+    case MIPI_DSI_VSYNC_END:
+    case MIPI_DSI_HSYNC_START:
+    case MIPI_DSI_HSYNC_END:
+    case MIPI_DSI_COMPRESSION_MODE:
+    case MIPI_DSI_END_OF_TRANSMISSION:
+    case MIPI_DSI_COLOR_MODE_OFF:
+    case MIPI_DSI_COLOR_MODE_ON:
+    case MIPI_DSI_SHUTDOWN_PERIPHERAL:
+    case MIPI_DSI_TURN_ON_PERIPHERAL:
+    case MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM:
+    case MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM:
+    case MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM:
+    case MIPI_DSI_GENERIC_READ_0_PARAM:
+    case MIPI_DSI_GENERIC_READ_1_PARAM:
+    case MIPI_DSI_GENERIC_READ_2_PARAM:
+    case MIPI_DSI_DCS_SHORT_WRITE_0_PARAM:
+    case MIPI_DSI_DCS_SHORT_WRITE_1_PARAM:
+    case MIPI_DSI_DCS_READ_0_PARAM:
+    case MIPI_DSI_EXECUTE_QUEUE:
+    case MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE:
+      return true;

Review Comment:
   add 2 more spaces for case block



##########
drivers/video/mipidsi/mipi_dsi_host_driver.c:
##########
@@ -0,0 +1,209 @@
+/****************************************************************************
+ * drivers/video/mipidsi/mipi_dsi_host_driver.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <debug.h>
+#include <stdio.h>
+
+#include <nuttx/kmalloc.h>
+
+#include "mipi_dsi.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Device naming ************************************************************/
+
+#define MIPI_DSI_HOSTNAME_FMT "/dev/dsi%d/host"
+#define MIPI_DSI_HOSTNAME_LEN 128
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* Driver state structure */
+
+struct mipi_dsi_host_driver_s
+{
+  FAR struct mipi_dsi_host *host;
+  mutex_t lock;                           /* Mutual exclusion */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static ssize_t dsi_host_read(FAR struct file *filep, FAR char *buffer,
+                             size_t len);
+static ssize_t dsi_host_write(FAR struct file *filep, FAR const char *buffer,
+                              size_t len);
+static int     dsi_host_ioctl(FAR struct file *filep, int cmd,
+                              unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static const struct file_operations dsi_host_fops =
+{
+  NULL,             /* open */
+  NULL,             /* close */
+  dsi_host_read,    /* read */
+  dsi_host_write,   /* write */
+  NULL,             /* seek */
+  dsi_host_ioctl,   /* ioctl */
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: dsi_host_read
+ ****************************************************************************/
+
+static ssize_t dsi_host_read(FAR struct file *filep, FAR char *buffer,
+                             size_t len)
+{
+  return 0; /* Return EOF */
+}
+
+/****************************************************************************
+ * Name: DSI hostdrvr_write
+ ****************************************************************************/
+
+static ssize_t dsi_host_write(FAR struct file *filep, FAR const char *buffer,
+                              size_t len)
+{
+  return len; /* Say that everything was written */
+}
+
+/****************************************************************************
+ * Name: dsi_host_ioctl
+ ****************************************************************************/
+
+static int dsi_host_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
+{
+  FAR struct mipi_dsi_host_driver_s *priv;
+  FAR struct inode *inode;
+  FAR struct mipi_dsi_msg *msg;
+  FAR struct mipi_dsi_host *host;
+  int ret;
+
+  /* Get our private data structure */
+
+  DEBUGASSERT(filep != NULL && filep->f_inode != NULL);
+  inode = filep->f_inode;
+
+  priv = inode->i_private;
+  DEBUGASSERT(priv);
+
+  /* Get exclusive access to the dsi host driver state structure */
+
+  ret = nxmutex_lock(&priv->lock);
+  if (ret < 0)
+    {
+      return ret;
+    }
+
+  /* Process the IOCTL command */
+
+  switch (cmd)
+    {
+      case MIPIDSI_TRANSFER:
+        {
+          /* Get the reference to the mipi_dsi_msg structure */
+
+          msg = (FAR struct mipi_dsi_msg *)((uintptr_t)arg);
+
+          /* Get the reference to the mipi_dsi_host structure */
+
+          host = priv->host;
+          DEBUGASSERT(host != NULL && msg != NULL);
+
+          ret = host->ops->transfer(host, msg);
+        }

Review Comment:
   minor
   ```suggestion
         case MIPIDSI_TRANSFER:
           /* Get the reference to the mipi_dsi_msg structure */
   
           msg = (FAR struct mipi_dsi_msg *)((uintptr_t)arg);
   
           /* Get the reference to the mipi_dsi_host structure */
   
           host = priv->host;
           DEBUGASSERT(host != NULL && msg != NULL);
   
           ret = host->ops->transfer(host, msg);
   ```



##########
drivers/video/mipidsi/mipi_dsi_device.c:
##########
@@ -0,0 +1,1023 @@
+/****************************************************************************
+ * drivers/video/mipidsi/mipi_dsi_device.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <assert.h>
+#include <debug.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <nuttx/video/mipi_display.h>
+#include <nuttx/kmalloc.h>
+
+#include "mipi_dsi.h"
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mipi_dsi_transfer
+ *
+ * Description:
+ *   Transfer message to display modules
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *   msg - Message to transfer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transfered or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_transfer(FAR struct mipi_dsi_device *device,
+                          FAR struct mipi_dsi_msg *msg)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->transfer == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_LPM)
+    {
+      msg->flags |= MIPI_DSI_MSG_USE_LPM;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_AFTER_FRAME)
+    {
+      msg->flags |= MIPI_DSI_MSG_AFTER_FRAME;
+    }
+
+  return ops->transfer(device->host, msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_attach
+ *
+ * Description:
+ *   Attach a DSI device to its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_attach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->attach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->attach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_detach
+ *
+ * Description:
+ *   Detach a DSI device from its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_detach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->detach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->detach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_shutdown_peripheral
+ *
+ * Description:
+ *   Send a Shutdown Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_shutdown_peripheral(FAR struct mipi_dsi_device *device)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SHUTDOWN_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  int ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_turn_on_peripheral
+ *
+ * Description:
+ *   Send a Turn On Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_turn_on_peripheral(FAR struct mipi_dsi_device *device)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_TURN_ON_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_set_maximum_return_packet_size
+ *
+ * Description:
+ *   Specify the maximum size of the payload in a long packet transmitted
+ *   from the peripheral back to the device host processor
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   value - The maximum size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_set_maximum_return_packet_size(
+                          FAR struct mipi_dsi_device *device, uint16_t value)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { value & 0xff, value >> 8 },
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_compression_mode
+ *
+ * Description:
+ *   Enable / disable DSC on the peripheral. Enable or disable Display Stream
+ *   Compression on the peripheral using the default Picture Parameter Set
+ *   and VESA DSC 1.1 algorithm.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   enable - Whether to enable or disable the DSC
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_compression_mode(FAR struct mipi_dsi_device *device,
+                              bool enable)
+{
+  /* Note: Needs updating for non-default PPS or algorithm */
+
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_COMPRESSION_MODE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { enable & 0xff, 0 },
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_generic_write
+ *
+ * Description:
+ *   Transmit data using a generic write packet
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   payload - buffer containing the payload
+ *   size - size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_generic_write(FAR struct mipi_dsi_device *device,
+                           FAR const void *payload,
+                           size_t size)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_buf = payload,
+    .tx_len = size

Review Comment:
   ditto



##########
drivers/video/mipidsi/mipi_dsi_device.c:
##########
@@ -0,0 +1,1023 @@
+/****************************************************************************
+ * drivers/video/mipidsi/mipi_dsi_device.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <assert.h>
+#include <debug.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <nuttx/video/mipi_display.h>
+#include <nuttx/kmalloc.h>
+
+#include "mipi_dsi.h"
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mipi_dsi_transfer
+ *
+ * Description:
+ *   Transfer message to display modules
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *   msg - Message to transfer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transfered or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_transfer(FAR struct mipi_dsi_device *device,
+                          FAR struct mipi_dsi_msg *msg)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->transfer == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_LPM)
+    {
+      msg->flags |= MIPI_DSI_MSG_USE_LPM;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_AFTER_FRAME)
+    {
+      msg->flags |= MIPI_DSI_MSG_AFTER_FRAME;
+    }
+
+  return ops->transfer(device->host, msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_attach
+ *
+ * Description:
+ *   Attach a DSI device to its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_attach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->attach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->attach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_detach
+ *
+ * Description:
+ *   Detach a DSI device from its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_detach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->detach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->detach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_shutdown_peripheral
+ *
+ * Description:
+ *   Send a Shutdown Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_shutdown_peripheral(FAR struct mipi_dsi_device *device)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SHUTDOWN_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  int ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_turn_on_peripheral
+ *
+ * Description:
+ *   Send a Turn On Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_turn_on_peripheral(FAR struct mipi_dsi_device *device)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_TURN_ON_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_set_maximum_return_packet_size
+ *
+ * Description:
+ *   Specify the maximum size of the payload in a long packet transmitted
+ *   from the peripheral back to the device host processor
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   value - The maximum size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_set_maximum_return_packet_size(
+                          FAR struct mipi_dsi_device *device, uint16_t value)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { value & 0xff, value >> 8 },
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_compression_mode
+ *
+ * Description:
+ *   Enable / disable DSC on the peripheral. Enable or disable Display Stream
+ *   Compression on the peripheral using the default Picture Parameter Set
+ *   and VESA DSC 1.1 algorithm.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   enable - Whether to enable or disable the DSC
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_compression_mode(FAR struct mipi_dsi_device *device,
+                              bool enable)
+{
+  /* Note: Needs updating for non-default PPS or algorithm */
+
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_COMPRESSION_MODE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { enable & 0xff, 0 },
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_generic_write
+ *
+ * Description:
+ *   Transmit data using a generic write packet
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   payload - buffer containing the payload
+ *   size - size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_generic_write(FAR struct mipi_dsi_device *device,
+                           FAR const void *payload,
+                           size_t size)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_buf = payload,
+    .tx_len = size
+  };
+
+  switch (size)
+    {
+    case 0:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM;
+      break;
+
+    case 1:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM;
+      break;
+
+    case 2:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM;
+      break;
+
+    default:
+      msg.type = MIPI_DSI_LONG_GENERIC_WRITE;
+      break;
+    }
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_generic_read
+ *
+ * Description:
+ *   Receive data using a generic read packet.
+ *   This function will automatically choose the right data type depending on
+ *   the number of parameters passed in.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   params - buffer containing the request parameters
+ *   num_params - number of request parameters
+ *   data - buffer in which to return the received data
+ *   size - size of receive buffer
+ *
+ * Returned Value:
+ *   The number of bytes successfully read or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_generic_read(FAR struct mipi_dsi_device *device,
+                              FAR const void *params,
+                              size_t num_params,
+                              FAR void *data,
+                              size_t size)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_len = num_params,
+    .tx_buf = params,
+    .rx_len = size,
+    .rx_buf = data
+  };
+
+  switch (num_params)
+    {
+    case 0:
+      msg.type = MIPI_DSI_GENERIC_READ_0_PARAM;
+      break;
+    case 1:
+      msg.type = MIPI_DSI_GENERIC_READ_1_PARAM;
+      break;
+    case 2:
+      msg.type = MIPI_DSI_GENERIC_READ_2_PARAM;
+      break;
+    default:
+      return -EINVAL;
+    }
+
+  return mipi_dsi_transfer(device, &msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_dcs_write_buffer
+ *
+ * Description:
+ *   Transmit a DCS command with payload.
+ *   This function will automatically choose the right data type depending on
+ *   the command payload length.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   data - buffer containing data to be transmitted
+ *   len - size of transmission buffer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transmitted or a negative error
+ *   code on failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_dcs_write_buffer(FAR struct mipi_dsi_device *device,
+                                  FAR const void *data,
+                                  size_t len)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_buf = data,
+    .tx_len = len
+  };
+
+  switch (len)
+    {
+    case 0:
+      return -EINVAL;
+    case 1:
+      msg.type = MIPI_DSI_DCS_SHORT_WRITE_0_PARAM;
+      break;
+    case 2:
+      msg.type = MIPI_DSI_DCS_SHORT_WRITE_1_PARAM;
+      break;
+    default:
+      msg.type = MIPI_DSI_DCS_LONG_WRITE;
+      break;
+    }
+
+  return mipi_dsi_transfer(device, &msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_dcs_write
+ *
+ * Description:
+ *   Send DCS write command.
+ *   This function will automatically choose the right data type depending on
+ *   the command payload length.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   cmd - DCS command
+ *   data - buffer containing the command payload
+ *   len - command payload length
+ *
+ * Returned Value:
+ *   The number of bytes successfully transmitted or a negative error
+ *   code on failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_dcs_write(FAR struct mipi_dsi_device *device,
+                           uint8_t cmd,
+                           FAR const void *data,
+                           size_t len)
+{
+  ssize_t ret;
+  uint8_t stack_tx[8];
+  FAR uint8_t *tx = stack_tx;
+
+  if (len > sizeof(stack_tx) - 1)
+    {
+      tx = kmm_malloc(len + 1);
+      if (!tx)

Review Comment:
   minor
   ```suggestion
         if (tx == NULL)
   ```



##########
drivers/video/mipidsi/mipi_dsi_device.c:
##########
@@ -0,0 +1,1023 @@
+/****************************************************************************
+ * drivers/video/mipidsi/mipi_dsi_device.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <assert.h>
+#include <debug.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <nuttx/video/mipi_display.h>
+#include <nuttx/kmalloc.h>
+
+#include "mipi_dsi.h"
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mipi_dsi_transfer
+ *
+ * Description:
+ *   Transfer message to display modules
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *   msg - Message to transfer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transfered or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_transfer(FAR struct mipi_dsi_device *device,
+                          FAR struct mipi_dsi_msg *msg)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->transfer == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_LPM)
+    {
+      msg->flags |= MIPI_DSI_MSG_USE_LPM;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_AFTER_FRAME)
+    {
+      msg->flags |= MIPI_DSI_MSG_AFTER_FRAME;
+    }
+
+  return ops->transfer(device->host, msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_attach
+ *
+ * Description:
+ *   Attach a DSI device to its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_attach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->attach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->attach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_detach
+ *
+ * Description:
+ *   Detach a DSI device from its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_detach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->detach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->detach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_shutdown_peripheral
+ *
+ * Description:
+ *   Send a Shutdown Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_shutdown_peripheral(FAR struct mipi_dsi_device *device)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SHUTDOWN_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  int ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_turn_on_peripheral
+ *
+ * Description:
+ *   Send a Turn On Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_turn_on_peripheral(FAR struct mipi_dsi_device *device)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_TURN_ON_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_set_maximum_return_packet_size
+ *
+ * Description:
+ *   Specify the maximum size of the payload in a long packet transmitted
+ *   from the peripheral back to the device host processor
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   value - The maximum size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_set_maximum_return_packet_size(
+                          FAR struct mipi_dsi_device *device, uint16_t value)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { value & 0xff, value >> 8 },
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_compression_mode
+ *
+ * Description:
+ *   Enable / disable DSC on the peripheral. Enable or disable Display Stream
+ *   Compression on the peripheral using the default Picture Parameter Set
+ *   and VESA DSC 1.1 algorithm.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   enable - Whether to enable or disable the DSC
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_compression_mode(FAR struct mipi_dsi_device *device,
+                              bool enable)
+{
+  /* Note: Needs updating for non-default PPS or algorithm */
+
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_COMPRESSION_MODE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { enable & 0xff, 0 },
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_generic_write
+ *
+ * Description:
+ *   Transmit data using a generic write packet
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   payload - buffer containing the payload
+ *   size - size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_generic_write(FAR struct mipi_dsi_device *device,
+                           FAR const void *payload,
+                           size_t size)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_buf = payload,
+    .tx_len = size
+  };
+
+  switch (size)
+    {
+    case 0:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM;
+      break;
+
+    case 1:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM;
+      break;
+
+    case 2:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM;
+      break;
+
+    default:
+      msg.type = MIPI_DSI_LONG_GENERIC_WRITE;
+      break;
+    }
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_generic_read
+ *
+ * Description:
+ *   Receive data using a generic read packet.
+ *   This function will automatically choose the right data type depending on
+ *   the number of parameters passed in.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   params - buffer containing the request parameters
+ *   num_params - number of request parameters
+ *   data - buffer in which to return the received data
+ *   size - size of receive buffer
+ *
+ * Returned Value:
+ *   The number of bytes successfully read or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_generic_read(FAR struct mipi_dsi_device *device,
+                              FAR const void *params,
+                              size_t num_params,
+                              FAR void *data,
+                              size_t size)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_len = num_params,
+    .tx_buf = params,
+    .rx_len = size,
+    .rx_buf = data
+  };
+
+  switch (num_params)
+    {
+    case 0:
+      msg.type = MIPI_DSI_GENERIC_READ_0_PARAM;
+      break;
+    case 1:
+      msg.type = MIPI_DSI_GENERIC_READ_1_PARAM;
+      break;
+    case 2:
+      msg.type = MIPI_DSI_GENERIC_READ_2_PARAM;
+      break;
+    default:
+      return -EINVAL;

Review Comment:
   ```suggestion
         case 0:
           msg.type = MIPI_DSI_GENERIC_READ_0_PARAM;
           break;
         case 1:
           msg.type = MIPI_DSI_GENERIC_READ_1_PARAM;
           break;
         case 2:
           msg.type = MIPI_DSI_GENERIC_READ_2_PARAM;
           break;
         default:
           return -EINVAL;
   ```



##########
drivers/video/mipidsi/mipi_dsi_device.c:
##########
@@ -0,0 +1,1023 @@
+/****************************************************************************
+ * drivers/video/mipidsi/mipi_dsi_device.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <assert.h>
+#include <debug.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <nuttx/video/mipi_display.h>
+#include <nuttx/kmalloc.h>
+
+#include "mipi_dsi.h"
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mipi_dsi_transfer
+ *
+ * Description:
+ *   Transfer message to display modules
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *   msg - Message to transfer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transfered or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_transfer(FAR struct mipi_dsi_device *device,
+                          FAR struct mipi_dsi_msg *msg)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->transfer == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_LPM)
+    {
+      msg->flags |= MIPI_DSI_MSG_USE_LPM;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_AFTER_FRAME)
+    {
+      msg->flags |= MIPI_DSI_MSG_AFTER_FRAME;
+    }
+
+  return ops->transfer(device->host, msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_attach
+ *
+ * Description:
+ *   Attach a DSI device to its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_attach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->attach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->attach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_detach
+ *
+ * Description:
+ *   Detach a DSI device from its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_detach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->detach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->detach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_shutdown_peripheral
+ *
+ * Description:
+ *   Send a Shutdown Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_shutdown_peripheral(FAR struct mipi_dsi_device *device)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SHUTDOWN_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  int ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_turn_on_peripheral
+ *
+ * Description:
+ *   Send a Turn On Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_turn_on_peripheral(FAR struct mipi_dsi_device *device)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_TURN_ON_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_set_maximum_return_packet_size
+ *
+ * Description:
+ *   Specify the maximum size of the payload in a long packet transmitted
+ *   from the peripheral back to the device host processor
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   value - The maximum size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_set_maximum_return_packet_size(
+                          FAR struct mipi_dsi_device *device, uint16_t value)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { value & 0xff, value >> 8 },
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_compression_mode
+ *
+ * Description:
+ *   Enable / disable DSC on the peripheral. Enable or disable Display Stream
+ *   Compression on the peripheral using the default Picture Parameter Set
+ *   and VESA DSC 1.1 algorithm.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   enable - Whether to enable or disable the DSC
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_compression_mode(FAR struct mipi_dsi_device *device,
+                              bool enable)
+{
+  /* Note: Needs updating for non-default PPS or algorithm */
+
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_COMPRESSION_MODE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { enable & 0xff, 0 },
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_generic_write
+ *
+ * Description:
+ *   Transmit data using a generic write packet
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   payload - buffer containing the payload
+ *   size - size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_generic_write(FAR struct mipi_dsi_device *device,
+                           FAR const void *payload,
+                           size_t size)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_buf = payload,
+    .tx_len = size
+  };
+
+  switch (size)
+    {
+    case 0:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM;
+      break;
+
+    case 1:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM;
+      break;
+
+    case 2:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM;
+      break;
+
+    default:
+      msg.type = MIPI_DSI_LONG_GENERIC_WRITE;
+      break;
+    }
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_generic_read
+ *
+ * Description:
+ *   Receive data using a generic read packet.
+ *   This function will automatically choose the right data type depending on
+ *   the number of parameters passed in.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   params - buffer containing the request parameters
+ *   num_params - number of request parameters
+ *   data - buffer in which to return the received data
+ *   size - size of receive buffer
+ *
+ * Returned Value:
+ *   The number of bytes successfully read or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_generic_read(FAR struct mipi_dsi_device *device,
+                              FAR const void *params,
+                              size_t num_params,
+                              FAR void *data,
+                              size_t size)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_len = num_params,
+    .tx_buf = params,
+    .rx_len = size,
+    .rx_buf = data
+  };
+
+  switch (num_params)
+    {
+    case 0:
+      msg.type = MIPI_DSI_GENERIC_READ_0_PARAM;
+      break;
+    case 1:
+      msg.type = MIPI_DSI_GENERIC_READ_1_PARAM;
+      break;
+    case 2:
+      msg.type = MIPI_DSI_GENERIC_READ_2_PARAM;
+      break;
+    default:
+      return -EINVAL;
+    }
+
+  return mipi_dsi_transfer(device, &msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_dcs_write_buffer
+ *
+ * Description:
+ *   Transmit a DCS command with payload.
+ *   This function will automatically choose the right data type depending on
+ *   the command payload length.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   data - buffer containing data to be transmitted
+ *   len - size of transmission buffer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transmitted or a negative error
+ *   code on failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_dcs_write_buffer(FAR struct mipi_dsi_device *device,
+                                  FAR const void *data,
+                                  size_t len)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_buf = data,

Review Comment:
   ditto



##########
drivers/video/mipidsi/mipi_dsi_device.c:
##########
@@ -0,0 +1,1023 @@
+/****************************************************************************
+ * drivers/video/mipidsi/mipi_dsi_device.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <assert.h>
+#include <debug.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <nuttx/video/mipi_display.h>
+#include <nuttx/kmalloc.h>
+
+#include "mipi_dsi.h"
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mipi_dsi_transfer
+ *
+ * Description:
+ *   Transfer message to display modules
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *   msg - Message to transfer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transfered or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_transfer(FAR struct mipi_dsi_device *device,
+                          FAR struct mipi_dsi_msg *msg)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->transfer == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_LPM)
+    {
+      msg->flags |= MIPI_DSI_MSG_USE_LPM;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_AFTER_FRAME)
+    {
+      msg->flags |= MIPI_DSI_MSG_AFTER_FRAME;
+    }
+
+  return ops->transfer(device->host, msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_attach
+ *
+ * Description:
+ *   Attach a DSI device to its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_attach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->attach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->attach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_detach
+ *
+ * Description:
+ *   Detach a DSI device from its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_detach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->detach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->detach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_shutdown_peripheral
+ *
+ * Description:
+ *   Send a Shutdown Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_shutdown_peripheral(FAR struct mipi_dsi_device *device)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SHUTDOWN_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  int ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_turn_on_peripheral
+ *
+ * Description:
+ *   Send a Turn On Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_turn_on_peripheral(FAR struct mipi_dsi_device *device)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_TURN_ON_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_set_maximum_return_packet_size
+ *
+ * Description:
+ *   Specify the maximum size of the payload in a long packet transmitted
+ *   from the peripheral back to the device host processor
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   value - The maximum size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_set_maximum_return_packet_size(
+                          FAR struct mipi_dsi_device *device, uint16_t value)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { value & 0xff, value >> 8 },
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_compression_mode
+ *
+ * Description:
+ *   Enable / disable DSC on the peripheral. Enable or disable Display Stream
+ *   Compression on the peripheral using the default Picture Parameter Set
+ *   and VESA DSC 1.1 algorithm.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   enable - Whether to enable or disable the DSC
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_compression_mode(FAR struct mipi_dsi_device *device,
+                              bool enable)
+{
+  /* Note: Needs updating for non-default PPS or algorithm */
+
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_COMPRESSION_MODE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { enable & 0xff, 0 },
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_generic_write
+ *
+ * Description:
+ *   Transmit data using a generic write packet
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   payload - buffer containing the payload
+ *   size - size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_generic_write(FAR struct mipi_dsi_device *device,
+                           FAR const void *payload,
+                           size_t size)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_buf = payload,
+    .tx_len = size
+  };
+
+  switch (size)
+    {
+    case 0:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM;
+      break;
+
+    case 1:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM;
+      break;
+
+    case 2:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM;
+      break;
+
+    default:
+      msg.type = MIPI_DSI_LONG_GENERIC_WRITE;
+      break;
+    }
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_generic_read
+ *
+ * Description:
+ *   Receive data using a generic read packet.
+ *   This function will automatically choose the right data type depending on
+ *   the number of parameters passed in.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   params - buffer containing the request parameters
+ *   num_params - number of request parameters
+ *   data - buffer in which to return the received data
+ *   size - size of receive buffer
+ *
+ * Returned Value:
+ *   The number of bytes successfully read or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_generic_read(FAR struct mipi_dsi_device *device,
+                              FAR const void *params,
+                              size_t num_params,
+                              FAR void *data,
+                              size_t size)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_len = num_params,
+    .tx_buf = params,
+    .rx_len = size,
+    .rx_buf = data
+  };
+
+  switch (num_params)
+    {
+    case 0:
+      msg.type = MIPI_DSI_GENERIC_READ_0_PARAM;
+      break;
+    case 1:
+      msg.type = MIPI_DSI_GENERIC_READ_1_PARAM;
+      break;
+    case 2:
+      msg.type = MIPI_DSI_GENERIC_READ_2_PARAM;
+      break;
+    default:
+      return -EINVAL;
+    }
+
+  return mipi_dsi_transfer(device, &msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_dcs_write_buffer
+ *
+ * Description:
+ *   Transmit a DCS command with payload.
+ *   This function will automatically choose the right data type depending on
+ *   the command payload length.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   data - buffer containing data to be transmitted
+ *   len - size of transmission buffer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transmitted or a negative error
+ *   code on failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_dcs_write_buffer(FAR struct mipi_dsi_device *device,
+                                  FAR const void *data,
+                                  size_t len)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_buf = data,
+    .tx_len = len
+  };
+
+  switch (len)
+    {
+    case 0:
+      return -EINVAL;
+    case 1:
+      msg.type = MIPI_DSI_DCS_SHORT_WRITE_0_PARAM;
+      break;
+    case 2:
+      msg.type = MIPI_DSI_DCS_SHORT_WRITE_1_PARAM;
+      break;
+    default:
+      msg.type = MIPI_DSI_DCS_LONG_WRITE;
+      break;
+    }
+
+  return mipi_dsi_transfer(device, &msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_dcs_write
+ *
+ * Description:
+ *   Send DCS write command.
+ *   This function will automatically choose the right data type depending on
+ *   the command payload length.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   cmd - DCS command
+ *   data - buffer containing the command payload
+ *   len - command payload length
+ *
+ * Returned Value:
+ *   The number of bytes successfully transmitted or a negative error
+ *   code on failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_dcs_write(FAR struct mipi_dsi_device *device,
+                           uint8_t cmd,
+                           FAR const void *data,
+                           size_t len)
+{
+  ssize_t ret;
+  uint8_t stack_tx[8];
+  FAR uint8_t *tx = stack_tx;
+
+  if (len > sizeof(stack_tx) - 1)
+    {
+      tx = kmm_malloc(len + 1);
+      if (!tx)
+        {
+          return -ENOMEM;
+        }
+    }
+
+  /* concatenate the DCS command byte and the payload */
+
+  tx[0] = cmd;
+  if (data)

Review Comment:
   minor
   ```suggestion
     if (data != NULL)
   ```



##########
drivers/video/mipidsi/mipi_dsi_device.c:
##########
@@ -0,0 +1,1023 @@
+/****************************************************************************
+ * drivers/video/mipidsi/mipi_dsi_device.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <assert.h>
+#include <debug.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <nuttx/video/mipi_display.h>
+#include <nuttx/kmalloc.h>
+
+#include "mipi_dsi.h"
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mipi_dsi_transfer
+ *
+ * Description:
+ *   Transfer message to display modules
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *   msg - Message to transfer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transfered or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_transfer(FAR struct mipi_dsi_device *device,
+                          FAR struct mipi_dsi_msg *msg)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->transfer == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_LPM)
+    {
+      msg->flags |= MIPI_DSI_MSG_USE_LPM;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_AFTER_FRAME)
+    {
+      msg->flags |= MIPI_DSI_MSG_AFTER_FRAME;
+    }
+
+  return ops->transfer(device->host, msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_attach
+ *
+ * Description:
+ *   Attach a DSI device to its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_attach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->attach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->attach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_detach
+ *
+ * Description:
+ *   Detach a DSI device from its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_detach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->detach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->detach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_shutdown_peripheral
+ *
+ * Description:
+ *   Send a Shutdown Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_shutdown_peripheral(FAR struct mipi_dsi_device *device)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SHUTDOWN_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  int ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_turn_on_peripheral
+ *
+ * Description:
+ *   Send a Turn On Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_turn_on_peripheral(FAR struct mipi_dsi_device *device)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_TURN_ON_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_set_maximum_return_packet_size
+ *
+ * Description:
+ *   Specify the maximum size of the payload in a long packet transmitted
+ *   from the peripheral back to the device host processor
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   value - The maximum size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_set_maximum_return_packet_size(
+                          FAR struct mipi_dsi_device *device, uint16_t value)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { value & 0xff, value >> 8 },
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_compression_mode
+ *
+ * Description:
+ *   Enable / disable DSC on the peripheral. Enable or disable Display Stream
+ *   Compression on the peripheral using the default Picture Parameter Set
+ *   and VESA DSC 1.1 algorithm.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   enable - Whether to enable or disable the DSC
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_compression_mode(FAR struct mipi_dsi_device *device,
+                              bool enable)
+{
+  /* Note: Needs updating for non-default PPS or algorithm */
+
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_COMPRESSION_MODE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { enable & 0xff, 0 },
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_generic_write
+ *
+ * Description:
+ *   Transmit data using a generic write packet
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   payload - buffer containing the payload
+ *   size - size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_generic_write(FAR struct mipi_dsi_device *device,
+                           FAR const void *payload,
+                           size_t size)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_buf = payload,
+    .tx_len = size
+  };
+
+  switch (size)
+    {
+    case 0:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM;
+      break;
+
+    case 1:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM;
+      break;
+
+    case 2:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM;
+      break;
+
+    default:
+      msg.type = MIPI_DSI_LONG_GENERIC_WRITE;
+      break;
+    }
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_generic_read
+ *
+ * Description:
+ *   Receive data using a generic read packet.
+ *   This function will automatically choose the right data type depending on
+ *   the number of parameters passed in.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   params - buffer containing the request parameters
+ *   num_params - number of request parameters
+ *   data - buffer in which to return the received data
+ *   size - size of receive buffer
+ *
+ * Returned Value:
+ *   The number of bytes successfully read or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_generic_read(FAR struct mipi_dsi_device *device,
+                              FAR const void *params,
+                              size_t num_params,
+                              FAR void *data,
+                              size_t size)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_len = num_params,
+    .tx_buf = params,
+    .rx_len = size,
+    .rx_buf = data
+  };
+
+  switch (num_params)
+    {
+    case 0:
+      msg.type = MIPI_DSI_GENERIC_READ_0_PARAM;
+      break;
+    case 1:
+      msg.type = MIPI_DSI_GENERIC_READ_1_PARAM;
+      break;
+    case 2:
+      msg.type = MIPI_DSI_GENERIC_READ_2_PARAM;
+      break;
+    default:
+      return -EINVAL;
+    }
+
+  return mipi_dsi_transfer(device, &msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_dcs_write_buffer
+ *
+ * Description:
+ *   Transmit a DCS command with payload.
+ *   This function will automatically choose the right data type depending on
+ *   the command payload length.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   data - buffer containing data to be transmitted
+ *   len - size of transmission buffer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transmitted or a negative error
+ *   code on failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_dcs_write_buffer(FAR struct mipi_dsi_device *device,
+                                  FAR const void *data,
+                                  size_t len)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_buf = data,
+    .tx_len = len
+  };
+
+  switch (len)
+    {
+    case 0:
+      return -EINVAL;
+    case 1:
+      msg.type = MIPI_DSI_DCS_SHORT_WRITE_0_PARAM;
+      break;
+    case 2:
+      msg.type = MIPI_DSI_DCS_SHORT_WRITE_1_PARAM;
+      break;
+    default:
+      msg.type = MIPI_DSI_DCS_LONG_WRITE;
+      break;
+    }
+
+  return mipi_dsi_transfer(device, &msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_dcs_write
+ *
+ * Description:
+ *   Send DCS write command.
+ *   This function will automatically choose the right data type depending on
+ *   the command payload length.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   cmd - DCS command
+ *   data - buffer containing the command payload
+ *   len - command payload length
+ *
+ * Returned Value:
+ *   The number of bytes successfully transmitted or a negative error
+ *   code on failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_dcs_write(FAR struct mipi_dsi_device *device,
+                           uint8_t cmd,
+                           FAR const void *data,
+                           size_t len)
+{
+  ssize_t ret;
+  uint8_t stack_tx[8];
+  FAR uint8_t *tx = stack_tx;
+
+  if (len > sizeof(stack_tx) - 1)
+    {
+      tx = kmm_malloc(len + 1);
+      if (!tx)
+        {
+          return -ENOMEM;
+        }
+    }
+
+  /* concatenate the DCS command byte and the payload */
+
+  tx[0] = cmd;
+  if (data)
+    {
+      memcpy(&tx[1], data, len);
+    }
+
+  ret = mipi_dsi_dcs_write_buffer(device, tx, len + 1);
+
+  if (tx != stack_tx)
+    {
+      kmm_free(tx);
+    }
+
+  return ret;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_dcs_read
+ *
+ * Description:
+ *   Send DCS read request command.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   cmd - DCS command
+ *   data - buffer in which to receive data
+ *   len - size of receive buffer
+ *
+ * Returned Value:
+ *   The number of bytes read or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_dcs_read(FAR struct mipi_dsi_device *device,
+                          uint8_t cmd,
+                          FAR void *data,
+                          size_t len)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_DCS_READ_0_PARAM,
+    .tx_buf = &cmd,
+    .tx_len = 1,
+    .rx_buf = data,
+    .rx_len = len
+  };
+
+  return mipi_dsi_transfer(device, &msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_dcs_nop
+ *
+ * Description:
+ *   Send DCS nop packet
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_dcs_nop(FAR struct mipi_dsi_device *device)
+{
+  int ret;
+
+  ret = mipi_dsi_dcs_write(device, MIPI_DCS_NOP, NULL, 0);
+  return ret < 0 ? ret : OK;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_dcs_soft_reset
+ *
+ * Description:
+ *   Send a software reset of the display module
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_dcs_soft_reset(FAR struct mipi_dsi_device *device)
+{
+  int ret;
+
+  ret = mipi_dsi_dcs_write(device, MIPI_DCS_SOFT_RESET, NULL, 0);
+

Review Comment:
   some similar places have new line while other do not. Maybe some common style can be used across this file?



##########
drivers/video/mipidsi/mipi_dsi_packet.c:
##########
@@ -0,0 +1,220 @@
+/****************************************************************************
+ * drivers/video/mipidsi/mipi_dsi_packet.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <assert.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <string.h>
+
+#include <nuttx/video/mipi_dsi.h>
+#include <nuttx/video/mipi_display.h>
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mipi_dsi_pixel_format_to_bpp
+ *
+ * Description:
+ *   Obtain the number of bits per pixel for any given pixel format defined
+ *   by the MIPI DSI specification
+ *
+ * Input Parameters:
+ *   fmt - MIPI DSI pixel format
+ *
+ * Returned Value:
+ *   The number of bits per pixel of the given pixel format.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_pixel_format_to_bpp(uint8_t fmt)
+{
+  switch (fmt)
+    {
+    case MIPI_DSI_FMT_RGB888:
+    case MIPI_DSI_FMT_RGB666:
+      return 24;
+    case MIPI_DSI_FMT_RGB666_PACKED:
+      return 18;
+    case MIPI_DSI_FMT_RGB565:
+      return 16;

Review Comment:
   ```suggestion
         case MIPI_DSI_FMT_RGB888:
         case MIPI_DSI_FMT_RGB666:
           return 24;
         case MIPI_DSI_FMT_RGB666_PACKED:
           return 18;
         case MIPI_DSI_FMT_RGB565:
           return 16;
   ```



##########
drivers/video/mipidsi/mipi_dsi_packet.c:
##########
@@ -0,0 +1,220 @@
+/****************************************************************************
+ * drivers/video/mipidsi/mipi_dsi_packet.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <assert.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <string.h>
+
+#include <nuttx/video/mipi_dsi.h>
+#include <nuttx/video/mipi_display.h>
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mipi_dsi_pixel_format_to_bpp
+ *
+ * Description:
+ *   Obtain the number of bits per pixel for any given pixel format defined
+ *   by the MIPI DSI specification
+ *
+ * Input Parameters:
+ *   fmt - MIPI DSI pixel format
+ *
+ * Returned Value:
+ *   The number of bits per pixel of the given pixel format.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_pixel_format_to_bpp(uint8_t fmt)
+{
+  switch (fmt)
+    {
+    case MIPI_DSI_FMT_RGB888:
+    case MIPI_DSI_FMT_RGB666:
+      return 24;
+    case MIPI_DSI_FMT_RGB666_PACKED:
+      return 18;
+    case MIPI_DSI_FMT_RGB565:
+      return 16;
+    }
+
+  return -EINVAL;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_packet_format_is_short
+ *
+ * Description:
+ *   Check if a packet is of the short format
+ *
+ * Input Parameters:
+ *   type - MIPI DSI data type of the packet
+ *
+ * Returned Value:
+ *   True if the packet for the given data type is a short packet, false
+ *   otherwise.
+ *
+ ****************************************************************************/
+
+bool mipi_dsi_packet_format_is_short(uint8_t type)
+{
+  switch (type)
+    {
+    case MIPI_DSI_VSYNC_START:
+    case MIPI_DSI_VSYNC_END:
+    case MIPI_DSI_HSYNC_START:
+    case MIPI_DSI_HSYNC_END:
+    case MIPI_DSI_COMPRESSION_MODE:
+    case MIPI_DSI_END_OF_TRANSMISSION:
+    case MIPI_DSI_COLOR_MODE_OFF:
+    case MIPI_DSI_COLOR_MODE_ON:
+    case MIPI_DSI_SHUTDOWN_PERIPHERAL:
+    case MIPI_DSI_TURN_ON_PERIPHERAL:
+    case MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM:
+    case MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM:
+    case MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM:
+    case MIPI_DSI_GENERIC_READ_0_PARAM:
+    case MIPI_DSI_GENERIC_READ_1_PARAM:
+    case MIPI_DSI_GENERIC_READ_2_PARAM:
+    case MIPI_DSI_DCS_SHORT_WRITE_0_PARAM:
+    case MIPI_DSI_DCS_SHORT_WRITE_1_PARAM:
+    case MIPI_DSI_DCS_READ_0_PARAM:
+    case MIPI_DSI_EXECUTE_QUEUE:
+    case MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE:
+      return true;
+    }
+
+  return false;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_packet_format_is_long
+ *
+ * Description:
+ *   Check if a packet is of the long format
+ *
+ * Input Parameters:
+ *   type - MIPI DSI data type of the packet
+ *
+ * Returned Value:
+ *   True if the packet for the given data type is a long packet, false
+ *   otherwise.
+ *
+ ****************************************************************************/
+
+bool mipi_dsi_packet_format_is_long(uint8_t type)
+{
+  switch (type)
+    {
+    case MIPI_DSI_NULL_PACKET:
+    case MIPI_DSI_BLANKING_PACKET:
+    case MIPI_DSI_LONG_GENERIC_WRITE:
+    case MIPI_DSI_DCS_LONG_WRITE:
+    case MIPI_DSI_PICTURE_PARAMETER_SET:
+    case MIPI_DSI_COMPRESSED_PIXEL_STREAM:
+    case MIPI_DSI_LOOSELY_PACKED_PIXEL_STREAM_YCBCR20:
+    case MIPI_DSI_PACKED_PIXEL_STREAM_YCBCR24:
+    case MIPI_DSI_PACKED_PIXEL_STREAM_YCBCR16:
+    case MIPI_DSI_PACKED_PIXEL_STREAM_RGB30:
+    case MIPI_DSI_PACKED_PIXEL_STREAM_RGB36:
+    case MIPI_DSI_PACKED_PIXEL_STREAM_YCBCR12:
+    case MIPI_DSI_PACKED_PIXEL_STREAM_RGB16:
+    case MIPI_DSI_PACKED_PIXEL_STREAM_RGB18:
+    case MIPI_DSI_PIXEL_STREAM_3BYTE_RGB18:
+    case MIPI_DSI_PACKED_PIXEL_STREAM_RGB24:
+      return true;

Review Comment:
   ditto



##########
drivers/video/mipidsi/mipi_dsi_device.c:
##########
@@ -0,0 +1,1023 @@
+/****************************************************************************
+ * drivers/video/mipidsi/mipi_dsi_device.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <assert.h>
+#include <debug.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <nuttx/video/mipi_display.h>
+#include <nuttx/kmalloc.h>
+
+#include "mipi_dsi.h"
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mipi_dsi_transfer
+ *
+ * Description:
+ *   Transfer message to display modules
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *   msg - Message to transfer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transfered or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_transfer(FAR struct mipi_dsi_device *device,
+                          FAR struct mipi_dsi_msg *msg)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->transfer == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_LPM)
+    {
+      msg->flags |= MIPI_DSI_MSG_USE_LPM;
+    }
+
+  if (device->mode_flags & MIPI_DSI_MODE_AFTER_FRAME)
+    {
+      msg->flags |= MIPI_DSI_MSG_AFTER_FRAME;
+    }
+
+  return ops->transfer(device->host, msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_attach
+ *
+ * Description:
+ *   Attach a DSI device to its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_attach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->attach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->attach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_detach
+ *
+ * Description:
+ *   Detach a DSI device from its DSI host
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_detach(FAR struct mipi_dsi_device *device)
+{
+  FAR const struct mipi_dsi_host_ops *ops = device->host->ops;
+
+  if (ops == NULL || ops->detach == NULL)
+    {
+      return -ENOSYS;
+    }
+
+  return ops->detach(device->host, device);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_shutdown_peripheral
+ *
+ * Description:
+ *   Send a Shutdown Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_shutdown_peripheral(FAR struct mipi_dsi_device *device)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SHUTDOWN_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  int ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_turn_on_peripheral
+ *
+ * Description:
+ *   Send a Turn On Peripheral command to the device device
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_turn_on_peripheral(FAR struct mipi_dsi_device *device)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_TURN_ON_PERIPHERAL,
+    .tx_buf = (uint8_t [2]) { 0, 0 },
+    .tx_len = 2,
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_set_maximum_return_packet_size
+ *
+ * Description:
+ *   Specify the maximum size of the payload in a long packet transmitted
+ *   from the peripheral back to the device host processor
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   value - The maximum size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_set_maximum_return_packet_size(
+                          FAR struct mipi_dsi_device *device, uint16_t value)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { value & 0xff, value >> 8 },
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_compression_mode
+ *
+ * Description:
+ *   Enable / disable DSC on the peripheral. Enable or disable Display Stream
+ *   Compression on the peripheral using the default Picture Parameter Set
+ *   and VESA DSC 1.1 algorithm.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   enable - Whether to enable or disable the DSC
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_compression_mode(FAR struct mipi_dsi_device *device,
+                              bool enable)
+{
+  /* Note: Needs updating for non-default PPS or algorithm */
+
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_COMPRESSION_MODE,
+    .tx_len = 2,
+    .tx_buf = (uint8_t [2]) { enable & 0xff, 0 },
+  };
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_generic_write
+ *
+ * Description:
+ *   Transmit data using a generic write packet
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   payload - buffer containing the payload
+ *   size - size of the payload
+ *
+ * Returned Value:
+ *   OK on success or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+int mipi_dsi_generic_write(FAR struct mipi_dsi_device *device,
+                           FAR const void *payload,
+                           size_t size)
+{
+  int ret;
+
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_buf = payload,
+    .tx_len = size
+  };
+
+  switch (size)
+    {
+    case 0:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM;
+      break;
+
+    case 1:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM;
+      break;
+
+    case 2:
+      msg.type = MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM;
+      break;
+
+    default:
+      msg.type = MIPI_DSI_LONG_GENERIC_WRITE;
+      break;
+    }
+
+  ret = mipi_dsi_transfer(device, &msg);
+  return ret < 0 ? ret : 0;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_generic_read
+ *
+ * Description:
+ *   Receive data using a generic read packet.
+ *   This function will automatically choose the right data type depending on
+ *   the number of parameters passed in.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   params - buffer containing the request parameters
+ *   num_params - number of request parameters
+ *   data - buffer in which to return the received data
+ *   size - size of receive buffer
+ *
+ * Returned Value:
+ *   The number of bytes successfully read or a negative error code on
+ *   failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_generic_read(FAR struct mipi_dsi_device *device,
+                              FAR const void *params,
+                              size_t num_params,
+                              FAR void *data,
+                              size_t size)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_len = num_params,
+    .tx_buf = params,
+    .rx_len = size,
+    .rx_buf = data
+  };
+
+  switch (num_params)
+    {
+    case 0:
+      msg.type = MIPI_DSI_GENERIC_READ_0_PARAM;
+      break;
+    case 1:
+      msg.type = MIPI_DSI_GENERIC_READ_1_PARAM;
+      break;
+    case 2:
+      msg.type = MIPI_DSI_GENERIC_READ_2_PARAM;
+      break;
+    default:
+      return -EINVAL;
+    }
+
+  return mipi_dsi_transfer(device, &msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_dcs_write_buffer
+ *
+ * Description:
+ *   Transmit a DCS command with payload.
+ *   This function will automatically choose the right data type depending on
+ *   the command payload length.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   data - buffer containing data to be transmitted
+ *   len - size of transmission buffer
+ *
+ * Returned Value:
+ *   The number of bytes successfully transmitted or a negative error
+ *   code on failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_dcs_write_buffer(FAR struct mipi_dsi_device *device,
+                                  FAR const void *data,
+                                  size_t len)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .tx_buf = data,
+    .tx_len = len
+  };
+
+  switch (len)
+    {
+    case 0:
+      return -EINVAL;
+    case 1:
+      msg.type = MIPI_DSI_DCS_SHORT_WRITE_0_PARAM;
+      break;
+    case 2:
+      msg.type = MIPI_DSI_DCS_SHORT_WRITE_1_PARAM;
+      break;
+    default:
+      msg.type = MIPI_DSI_DCS_LONG_WRITE;
+      break;
+    }
+
+  return mipi_dsi_transfer(device, &msg);
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_dcs_write
+ *
+ * Description:
+ *   Send DCS write command.
+ *   This function will automatically choose the right data type depending on
+ *   the command payload length.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   cmd - DCS command
+ *   data - buffer containing the command payload
+ *   len - command payload length
+ *
+ * Returned Value:
+ *   The number of bytes successfully transmitted or a negative error
+ *   code on failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_dcs_write(FAR struct mipi_dsi_device *device,
+                           uint8_t cmd,
+                           FAR const void *data,
+                           size_t len)
+{
+  ssize_t ret;
+  uint8_t stack_tx[8];
+  FAR uint8_t *tx = stack_tx;
+
+  if (len > sizeof(stack_tx) - 1)
+    {
+      tx = kmm_malloc(len + 1);
+      if (!tx)
+        {
+          return -ENOMEM;
+        }
+    }
+
+  /* concatenate the DCS command byte and the payload */
+
+  tx[0] = cmd;
+  if (data)
+    {
+      memcpy(&tx[1], data, len);
+    }
+
+  ret = mipi_dsi_dcs_write_buffer(device, tx, len + 1);
+
+  if (tx != stack_tx)
+    {
+      kmm_free(tx);
+    }
+
+  return ret;
+}
+
+/****************************************************************************
+ * Name: mipi_dsi_dcs_read
+ *
+ * Description:
+ *   Send DCS read request command.
+ *
+ * Input Parameters:
+ *   device - DSI peripheral device
+ *   cmd - DCS command
+ *   data - buffer in which to receive data
+ *   len - size of receive buffer
+ *
+ * Returned Value:
+ *   The number of bytes read or a negative error code on failure.
+ *
+ ****************************************************************************/
+
+ssize_t mipi_dsi_dcs_read(FAR struct mipi_dsi_device *device,
+                          uint8_t cmd,
+                          FAR void *data,
+                          size_t len)
+{
+  struct mipi_dsi_msg msg =
+  {
+    .channel = device->channel,
+    .type = MIPI_DSI_DCS_READ_0_PARAM,
+    .tx_buf = &cmd,
+    .tx_len = 1,
+    .rx_buf = data,
+    .rx_len = len

Review Comment:
   ditto



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[GitHub] [nuttx] xiaoxiang781216 commented on pull request #8103: feat: add mipidsi support

[GitBox <gi...@apache.org>]

xiaoxiang781216 commented on PR #8103:
URL: https://github.com/apache/nuttx/pull/8103#issuecomment-1381532384

   @lupyuen @shuai532209720 provide a general mipi dsi driver framework. Your owrk on A64 may benefit from it. 


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