[GitHub] [incubator-nuttx] pkarashchenko commented on a diff in pull request #6634: drivers/lcd: Add support to use APA102 LED Matrix as LCD Display

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

pkarashchenko commented on code in PR #6634:
URL: https://github.com/apache/incubator-nuttx/pull/6634#discussion_r923242198


##########
drivers/lcd/apa102.c:
##########
@@ -0,0 +1,667 @@
+/****************************************************************************
+ * drivers/lcd/apa102.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.
+ *
+ ****************************************************************************/
+
+/* Driver to create a display using RBG LEDs APA102 chained together */
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/spi/spi.h>
+#include <nuttx/lcd/lcd.h>
+#include <nuttx/lcd/apa102.h>
+#include <nuttx/leds/apa102.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define MAX(a,b)    ((a)>(b)?(a):(b))

Review Comment:
   ```suggestion
   #ifndef MAX
   #  define MAX(a,b)    ((a) > (b) ? (a) : (b))
   #endif
   ```



##########
drivers/lcd/apa102.c:
##########
@@ -0,0 +1,667 @@
+/****************************************************************************
+ * drivers/lcd/apa102.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.
+ *
+ ****************************************************************************/
+
+/* Driver to create a display using RBG LEDs APA102 chained together */
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/spi/spi.h>
+#include <nuttx/lcd/lcd.h>
+#include <nuttx/lcd/apa102.h>
+#include <nuttx/leds/apa102.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define MAX(a,b)    ((a)>(b)?(a):(b))
+
+/* Configuration ************************************************************/
+
+/* APA102 Configuration Settings:
+ *
+ * CONFIG_APA102_XRES - Specifies the number of physical
+ *   APA102 devices that are connected together horizontally.
+ *
+ * CONFIG_APA102_YRES - Specifies the number of physical
+ *   APA102 devices that are connected together vertically.
+ *
+ * CONFIG_LCD_INTENSITY - Defines the default bright of LEDs.
+ *
+ * Required LCD driver settings:
+ * CONFIG_LCD_APA102 - Enable APA102 support
+ *
+ */
+
+/* Verify that all configuration requirements have been met */
+
+/* SPI frequency */
+
+#ifndef CONFIG_APA102_FREQUENCY
+#  define CONFIG_APA102_FREQUENCY 10000000
+#endif
+
+/* APA102_COLUMNS determines the number of physical LEDs
+ * matrices that are used connected horizontally.
+ */
+
+#ifndef CONFIG_APA102_XRES
+#  define CONFIG_APA102_XRES 16
+#endif
+
+/* APA102_LINES determines the number of physical LEDs
+ * matrices that are used connected vertically.
+ */
+
+#ifndef CONFIG_APA102_YRES
+#  define CONFIG_APA102_YRES 16
+#endif
+
+/* Check contrast selection */
+
+#if !defined(CONFIG_LCD_MAXCONTRAST)
+#  define CONFIG_LCD_MAXCONTRAST 1
+#endif
+
+/* Color Properties *********************************************************/
+
+/* Display Resolution */
+
+#define APA102_XRES         CONFIG_APA102_XRES
+#define APA102_YRES         CONFIG_APA102_YRES
+
+/* Color depth and format */
+
+#define APA102_BPP          16
+#define APA102_COLORFMT     FB_FMT_RGB16_565
+
+#define APA102_LUT_SIZE     MAX(APA102_XRES, APA102_YRES)
+
+/* The size of the shadow frame buffer (4 bytes per LED) */
+
+#define APA102_FBSIZE       (APA102_XRES * APA102_YRES)
+
+/* LCD RGB Mapping */
+
+#ifdef CONFIG_FB_CMAP
+#  error "RGB color mapping not supported by this driver"
+#endif
+
+/* Cursor Controls */
+
+#ifdef CONFIG_FB_HWCURSOR
+#  error "Cursor control not supported by this driver"
+#endif
+
+/****************************************************************************
+ * Private Type Definition
+ ****************************************************************************/
+
+/* This structure describes the state of this driver */
+
+struct apa102_dev_s
+{
+  /* Publicly visible device structure */
+
+  struct lcd_dev_s dev;
+
+  /* Private LCD-specific information follows */
+
+  FAR struct spi_dev_s *spi;
+  uint8_t contrast;
+  uint8_t powered;
+
+  /* We need to send all the APA102 matrix screen once.
+   * So, create a framebuffer to save it in memory
+   */
+
+  struct apa102_ledstrip_s fb[APA102_FBSIZE];
+};
+
+/****************************************************************************
+ * Private Function Protototypes
+ ****************************************************************************/
+
+/* LCD Data Transfer Methods */
+
+static int apa102_putrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR const uint8_t *buffer,
+                         size_t npixels);
+static int apa102_getrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR uint8_t *buffer,
+                         size_t npixels);
+
+/* LCD Configuration */
+
+static int apa102_getvideoinfo(FAR struct lcd_dev_s *dev,
+                               FAR struct fb_videoinfo_s *vinfo);
+static int apa102_getplaneinfo(FAR struct lcd_dev_s *dev,
+                               unsigned int planeno,
+                               FAR struct lcd_planeinfo_s *pinfo);
+
+/* LCD Specific Controls */
+
+static int apa102_getpower(FAR struct lcd_dev_s *dev);
+static int apa102_setpower(FAR struct lcd_dev_s *dev, int power);
+static int apa102_getcontrast(FAR struct lcd_dev_s *dev);
+static int apa102_setcontrast(FAR struct lcd_dev_s *dev,
+                               unsigned int contrast);
+
+/* Initialization */
+
+static inline void up_clear(FAR struct apa102_dev_s  *priv);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* This is working memory allocated by the LCD driver for each LCD device
+ * and for each color plane.  This memory will hold one raster line of data.
+ * The size of the allocated run buffer must therefore be at least
+ * (bpp * xres / 8).  Actual alignment of the buffer must conform to the
+ * bitwidth of the underlying pixel type.
+ *
+ * If there are multiple planes, they may share the same working buffer
+ * because different planes will not be operate on concurrently.  However,
+ * if there are multiple LCD devices, they must each have unique run buffers.
+ */
+
+static uint8_t g_runbuffer[APA102_LUT_SIZE];
+
+/* This structure describes the overall LCD video controller */
+
+static const struct fb_videoinfo_s g_videoinfo =
+{
+  APA102_COLORFMT,    /* Color format: RGB16-565: RRRR RGGG GGGB BBBB */
+  APA102_XRES,        /* Horizontal resolution in pixel columns */
+  APA102_YRES,        /* Vertical resolution in pixel rows */
+  1,                  /* Number of color planes supported */
+};
+
+/* This is the standard, NuttX Plane information object */
+
+static const struct lcd_planeinfo_s g_planeinfo =
+{
+  .putrun = apa102_putrun,              /* Put a run into LCD memory */
+  .getrun = apa102_getrun,              /* Get a run from LCD memory */
+  .buffer = (FAR uint8_t *)g_runbuffer, /* Run scratch buffer */
+  .bpp    = APA102_BPP,                 /* Bits-per-pixel */

Review Comment:
   can we use C89 init?



##########
drivers/lcd/apa102.c:
##########
@@ -0,0 +1,667 @@
+/****************************************************************************
+ * drivers/lcd/apa102.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.
+ *
+ ****************************************************************************/
+
+/* Driver to create a display using RBG LEDs APA102 chained together */
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/spi/spi.h>
+#include <nuttx/lcd/lcd.h>
+#include <nuttx/lcd/apa102.h>
+#include <nuttx/leds/apa102.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define MAX(a,b)    ((a)>(b)?(a):(b))
+
+/* Configuration ************************************************************/
+
+/* APA102 Configuration Settings:
+ *
+ * CONFIG_APA102_XRES - Specifies the number of physical
+ *   APA102 devices that are connected together horizontally.
+ *
+ * CONFIG_APA102_YRES - Specifies the number of physical
+ *   APA102 devices that are connected together vertically.
+ *
+ * CONFIG_LCD_INTENSITY - Defines the default bright of LEDs.
+ *
+ * Required LCD driver settings:
+ * CONFIG_LCD_APA102 - Enable APA102 support
+ *
+ */
+
+/* Verify that all configuration requirements have been met */
+
+/* SPI frequency */
+
+#ifndef CONFIG_APA102_FREQUENCY
+#  define CONFIG_APA102_FREQUENCY 10000000
+#endif
+
+/* APA102_COLUMNS determines the number of physical LEDs
+ * matrices that are used connected horizontally.
+ */
+
+#ifndef CONFIG_APA102_XRES
+#  define CONFIG_APA102_XRES 16
+#endif
+
+/* APA102_LINES determines the number of physical LEDs
+ * matrices that are used connected vertically.
+ */
+
+#ifndef CONFIG_APA102_YRES
+#  define CONFIG_APA102_YRES 16
+#endif
+
+/* Check contrast selection */
+
+#if !defined(CONFIG_LCD_MAXCONTRAST)
+#  define CONFIG_LCD_MAXCONTRAST 1
+#endif
+
+/* Color Properties *********************************************************/
+
+/* Display Resolution */
+
+#define APA102_XRES         CONFIG_APA102_XRES
+#define APA102_YRES         CONFIG_APA102_YRES
+
+/* Color depth and format */
+
+#define APA102_BPP          16
+#define APA102_COLORFMT     FB_FMT_RGB16_565
+
+#define APA102_LUT_SIZE     MAX(APA102_XRES, APA102_YRES)
+
+/* The size of the shadow frame buffer (4 bytes per LED) */
+
+#define APA102_FBSIZE       (APA102_XRES * APA102_YRES)
+
+/* LCD RGB Mapping */
+
+#ifdef CONFIG_FB_CMAP
+#  error "RGB color mapping not supported by this driver"
+#endif
+
+/* Cursor Controls */
+
+#ifdef CONFIG_FB_HWCURSOR
+#  error "Cursor control not supported by this driver"
+#endif
+
+/****************************************************************************
+ * Private Type Definition
+ ****************************************************************************/
+
+/* This structure describes the state of this driver */
+
+struct apa102_dev_s
+{
+  /* Publicly visible device structure */
+
+  struct lcd_dev_s dev;
+
+  /* Private LCD-specific information follows */
+
+  FAR struct spi_dev_s *spi;
+  uint8_t contrast;
+  uint8_t powered;
+
+  /* We need to send all the APA102 matrix screen once.
+   * So, create a framebuffer to save it in memory
+   */
+
+  struct apa102_ledstrip_s fb[APA102_FBSIZE];
+};
+
+/****************************************************************************
+ * Private Function Protototypes
+ ****************************************************************************/
+
+/* LCD Data Transfer Methods */
+
+static int apa102_putrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR const uint8_t *buffer,
+                         size_t npixels);
+static int apa102_getrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR uint8_t *buffer,
+                         size_t npixels);
+
+/* LCD Configuration */
+
+static int apa102_getvideoinfo(FAR struct lcd_dev_s *dev,
+                               FAR struct fb_videoinfo_s *vinfo);
+static int apa102_getplaneinfo(FAR struct lcd_dev_s *dev,
+                               unsigned int planeno,
+                               FAR struct lcd_planeinfo_s *pinfo);
+
+/* LCD Specific Controls */
+
+static int apa102_getpower(FAR struct lcd_dev_s *dev);
+static int apa102_setpower(FAR struct lcd_dev_s *dev, int power);
+static int apa102_getcontrast(FAR struct lcd_dev_s *dev);
+static int apa102_setcontrast(FAR struct lcd_dev_s *dev,
+                               unsigned int contrast);
+
+/* Initialization */
+
+static inline void up_clear(FAR struct apa102_dev_s  *priv);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* This is working memory allocated by the LCD driver for each LCD device
+ * and for each color plane.  This memory will hold one raster line of data.
+ * The size of the allocated run buffer must therefore be at least
+ * (bpp * xres / 8).  Actual alignment of the buffer must conform to the
+ * bitwidth of the underlying pixel type.
+ *
+ * If there are multiple planes, they may share the same working buffer
+ * because different planes will not be operate on concurrently.  However,
+ * if there are multiple LCD devices, they must each have unique run buffers.
+ */
+
+static uint8_t g_runbuffer[APA102_LUT_SIZE];
+
+/* This structure describes the overall LCD video controller */
+
+static const struct fb_videoinfo_s g_videoinfo =
+{
+  APA102_COLORFMT,    /* Color format: RGB16-565: RRRR RGGG GGGB BBBB */
+  APA102_XRES,        /* Horizontal resolution in pixel columns */
+  APA102_YRES,        /* Vertical resolution in pixel rows */
+  1,                  /* Number of color planes supported */
+};
+
+/* This is the standard, NuttX Plane information object */
+
+static const struct lcd_planeinfo_s g_planeinfo =
+{
+  .putrun = apa102_putrun,              /* Put a run into LCD memory */
+  .getrun = apa102_getrun,              /* Get a run from LCD memory */
+  .buffer = (FAR uint8_t *)g_runbuffer, /* Run scratch buffer */
+  .bpp    = APA102_BPP,                 /* Bits-per-pixel */
+};
+
+/* This is the standard, NuttX LCD driver object */
+
+static struct apa102_dev_s g_apa102dev =
+{
+  /* struct lcd_dev_s */
+
+  {
+    /* LCD Configuration */
+
+    apa102_getvideoinfo,
+    apa102_getplaneinfo,
+
+#ifdef CONFIG_FB_CMAP
+    /* LCD RGB Mapping -- Not supported */
+
+    NULL,
+    NULL,
+#endif
+
+#ifdef CONFIG_FB_HWCURSOR
+    /* Cursor Controls -- Not supported */
+
+    NULL,
+    NULL,
+#endif
+
+    /* LCD Specific Controls */
+
+    apa102_getpower,
+    apa102_setpower,
+    apa102_getcontrast,
+    apa102_setcontrast,
+  },
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: rgb565_apa102
+ *
+ * Description:
+ *   Convert RGB565 to APA102 RGB888 format
+ *
+ ****************************************************************************/
+
+static struct apa102_ledstrip_s rgb565_apa102(uint16_t rgb565)
+{
+  struct apa102_ledstrip_s led;
+  led.red    = (rgb565 & 0b1111100000000000) >> 8;
+  led.green  = (rgb565 & 0b11111100000) >> 3;
+  led.blue   = (rgb565 & 0b11111) << 3;
+  led.bright = 0;
+  return led;
+}
+
+/****************************************************************************
+ * Name: apa102_rgb565
+ *
+ * Description:
+ *   Convert APA102 RGB888 to RGB565 format
+ *
+ ****************************************************************************/
+
+static uint16_t apa102_rgb565(struct apa102_ledstrip_s led)
+{
+  uint16_t pixel;
+
+  pixel  = (led.red & 0b11111000) << 8;
+  pixel |= (led.green & 0b11111100) << 3;
+  pixel |= (led.blue & 0b11111000) >> 3;
+  return pixel;
+}
+
+/****************************************************************************
+ * Name: apa102_configspi
+ *
+ * Description:
+ *   Set the SPI bus configuration
+ *
+ ****************************************************************************/
+
+static inline void apa102_configspi(FAR struct spi_dev_s *spi)
+{
+  /* Configure SPI for the APA102 */
+
+  SPI_SETMODE(spi, SPIDEV_MODE0);
+  SPI_SETBITS(spi, 8);
+  SPI_HWFEATURES(spi, 0);
+  SPI_SETFREQUENCY(spi, APA102_SPI_MAXFREQUENCY);
+}
+
+/****************************************************************************
+ * Name: apa102_write32
+ *
+ * Description:
+ *   Write 32-bit to APA102
+ *
+ ****************************************************************************/
+
+static inline void apa102_write32(FAR struct apa102_dev_s *priv,
+                                  FAR uint32_t value)
+{
+  /* If SPI bus is shared then lock and configure it */
+
+  SPI_LOCK(priv->spi, true);
+
+  /* Note: APA102 doesn't use chip select */
+
+  /* Send 32 bits (4 bytes) */
+
+  SPI_SEND(priv->spi, (value & 0xff));
+  SPI_SEND(priv->spi, ((value & 0xff00) >> 8));
+  SPI_SEND(priv->spi, ((value & 0xff0000) >> 16));
+  SPI_SEND(priv->spi, ((value & 0xff000000) >> 24));
+
+  /* Unlock bus */
+
+  SPI_LOCK(priv->spi, false);
+}
+
+/****************************************************************************
+ * Name:  apa102_putrun
+ *
+ * Description:
+ *   This method can be used to write a partial raster line to the LCD:
+ *
+ *   dev     - The lcd device
+ *   row     - Starting row to write to (range: 0 <= row < yres)
+ *   col     - Starting column to write to (range: 0 <= col <= xres-npixels)
+ *   buffer  - The buffer containing the run to be written to the LCD
+ *   npixels - The number of pixels to write to the LCD
+ *             (range: 0 < npixels <= xres-col)
+ *
+ ****************************************************************************/
+
+static int apa102_putrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                          fb_coord_t col, FAR const uint8_t *buffer,
+                          size_t npixels)

Review Comment:
   ```suggestion
   static int apa102_putrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
                            fb_coord_t col, FAR const uint8_t *buffer,
                            size_t npixels)
   ```



##########
drivers/lcd/apa102.c:
##########
@@ -0,0 +1,667 @@
+/****************************************************************************
+ * drivers/lcd/apa102.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.
+ *
+ ****************************************************************************/
+
+/* Driver to create a display using RBG LEDs APA102 chained together */
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/spi/spi.h>
+#include <nuttx/lcd/lcd.h>
+#include <nuttx/lcd/apa102.h>
+#include <nuttx/leds/apa102.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define MAX(a,b)    ((a)>(b)?(a):(b))
+
+/* Configuration ************************************************************/
+
+/* APA102 Configuration Settings:
+ *
+ * CONFIG_APA102_XRES - Specifies the number of physical
+ *   APA102 devices that are connected together horizontally.
+ *
+ * CONFIG_APA102_YRES - Specifies the number of physical
+ *   APA102 devices that are connected together vertically.
+ *
+ * CONFIG_LCD_INTENSITY - Defines the default bright of LEDs.
+ *
+ * Required LCD driver settings:
+ * CONFIG_LCD_APA102 - Enable APA102 support
+ *
+ */
+
+/* Verify that all configuration requirements have been met */
+
+/* SPI frequency */
+
+#ifndef CONFIG_APA102_FREQUENCY
+#  define CONFIG_APA102_FREQUENCY 10000000
+#endif
+
+/* APA102_COLUMNS determines the number of physical LEDs
+ * matrices that are used connected horizontally.
+ */
+
+#ifndef CONFIG_APA102_XRES
+#  define CONFIG_APA102_XRES 16
+#endif
+
+/* APA102_LINES determines the number of physical LEDs
+ * matrices that are used connected vertically.
+ */
+
+#ifndef CONFIG_APA102_YRES
+#  define CONFIG_APA102_YRES 16
+#endif
+
+/* Check contrast selection */
+
+#if !defined(CONFIG_LCD_MAXCONTRAST)
+#  define CONFIG_LCD_MAXCONTRAST 1
+#endif
+
+/* Color Properties *********************************************************/
+
+/* Display Resolution */
+
+#define APA102_XRES         CONFIG_APA102_XRES
+#define APA102_YRES         CONFIG_APA102_YRES
+
+/* Color depth and format */
+
+#define APA102_BPP          16
+#define APA102_COLORFMT     FB_FMT_RGB16_565
+
+#define APA102_LUT_SIZE     MAX(APA102_XRES, APA102_YRES)
+
+/* The size of the shadow frame buffer (4 bytes per LED) */
+
+#define APA102_FBSIZE       (APA102_XRES * APA102_YRES)
+
+/* LCD RGB Mapping */
+
+#ifdef CONFIG_FB_CMAP
+#  error "RGB color mapping not supported by this driver"
+#endif
+
+/* Cursor Controls */
+
+#ifdef CONFIG_FB_HWCURSOR
+#  error "Cursor control not supported by this driver"
+#endif
+
+/****************************************************************************
+ * Private Type Definition
+ ****************************************************************************/
+
+/* This structure describes the state of this driver */
+
+struct apa102_dev_s
+{
+  /* Publicly visible device structure */
+
+  struct lcd_dev_s dev;
+
+  /* Private LCD-specific information follows */
+
+  FAR struct spi_dev_s *spi;
+  uint8_t contrast;
+  uint8_t powered;
+
+  /* We need to send all the APA102 matrix screen once.
+   * So, create a framebuffer to save it in memory
+   */
+
+  struct apa102_ledstrip_s fb[APA102_FBSIZE];
+};
+
+/****************************************************************************
+ * Private Function Protototypes
+ ****************************************************************************/
+
+/* LCD Data Transfer Methods */
+
+static int apa102_putrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR const uint8_t *buffer,
+                         size_t npixels);
+static int apa102_getrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR uint8_t *buffer,
+                         size_t npixels);
+
+/* LCD Configuration */
+
+static int apa102_getvideoinfo(FAR struct lcd_dev_s *dev,
+                               FAR struct fb_videoinfo_s *vinfo);
+static int apa102_getplaneinfo(FAR struct lcd_dev_s *dev,
+                               unsigned int planeno,
+                               FAR struct lcd_planeinfo_s *pinfo);
+
+/* LCD Specific Controls */
+
+static int apa102_getpower(FAR struct lcd_dev_s *dev);
+static int apa102_setpower(FAR struct lcd_dev_s *dev, int power);
+static int apa102_getcontrast(FAR struct lcd_dev_s *dev);
+static int apa102_setcontrast(FAR struct lcd_dev_s *dev,
+                               unsigned int contrast);
+
+/* Initialization */
+
+static inline void up_clear(FAR struct apa102_dev_s  *priv);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* This is working memory allocated by the LCD driver for each LCD device
+ * and for each color plane.  This memory will hold one raster line of data.
+ * The size of the allocated run buffer must therefore be at least
+ * (bpp * xres / 8).  Actual alignment of the buffer must conform to the
+ * bitwidth of the underlying pixel type.
+ *
+ * If there are multiple planes, they may share the same working buffer
+ * because different planes will not be operate on concurrently.  However,
+ * if there are multiple LCD devices, they must each have unique run buffers.
+ */
+
+static uint8_t g_runbuffer[APA102_LUT_SIZE];
+
+/* This structure describes the overall LCD video controller */
+
+static const struct fb_videoinfo_s g_videoinfo =
+{
+  APA102_COLORFMT,    /* Color format: RGB16-565: RRRR RGGG GGGB BBBB */
+  APA102_XRES,        /* Horizontal resolution in pixel columns */
+  APA102_YRES,        /* Vertical resolution in pixel rows */
+  1,                  /* Number of color planes supported */
+};
+
+/* This is the standard, NuttX Plane information object */
+
+static const struct lcd_planeinfo_s g_planeinfo =
+{
+  .putrun = apa102_putrun,              /* Put a run into LCD memory */
+  .getrun = apa102_getrun,              /* Get a run from LCD memory */
+  .buffer = (FAR uint8_t *)g_runbuffer, /* Run scratch buffer */
+  .bpp    = APA102_BPP,                 /* Bits-per-pixel */
+};
+
+/* This is the standard, NuttX LCD driver object */
+
+static struct apa102_dev_s g_apa102dev =
+{
+  /* struct lcd_dev_s */
+
+  {
+    /* LCD Configuration */
+
+    apa102_getvideoinfo,
+    apa102_getplaneinfo,
+
+#ifdef CONFIG_FB_CMAP
+    /* LCD RGB Mapping -- Not supported */
+
+    NULL,
+    NULL,
+#endif
+
+#ifdef CONFIG_FB_HWCURSOR
+    /* Cursor Controls -- Not supported */
+
+    NULL,
+    NULL,
+#endif
+
+    /* LCD Specific Controls */
+
+    apa102_getpower,
+    apa102_setpower,
+    apa102_getcontrast,
+    apa102_setcontrast,
+  },
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: rgb565_apa102
+ *
+ * Description:
+ *   Convert RGB565 to APA102 RGB888 format
+ *
+ ****************************************************************************/
+
+static struct apa102_ledstrip_s rgb565_apa102(uint16_t rgb565)
+{
+  struct apa102_ledstrip_s led;
+  led.red    = (rgb565 & 0b1111100000000000) >> 8;
+  led.green  = (rgb565 & 0b11111100000) >> 3;
+  led.blue   = (rgb565 & 0b11111) << 3;
+  led.bright = 0;
+  return led;
+}
+
+/****************************************************************************
+ * Name: apa102_rgb565
+ *
+ * Description:
+ *   Convert APA102 RGB888 to RGB565 format
+ *
+ ****************************************************************************/
+
+static uint16_t apa102_rgb565(struct apa102_ledstrip_s led)
+{
+  uint16_t pixel;
+
+  pixel  = (led.red & 0b11111000) << 8;
+  pixel |= (led.green & 0b11111100) << 3;
+  pixel |= (led.blue & 0b11111000) >> 3;
+  return pixel;
+}
+
+/****************************************************************************
+ * Name: apa102_configspi
+ *
+ * Description:
+ *   Set the SPI bus configuration
+ *
+ ****************************************************************************/
+
+static inline void apa102_configspi(FAR struct spi_dev_s *spi)
+{
+  /* Configure SPI for the APA102 */
+
+  SPI_SETMODE(spi, SPIDEV_MODE0);
+  SPI_SETBITS(spi, 8);
+  SPI_HWFEATURES(spi, 0);
+  SPI_SETFREQUENCY(spi, APA102_SPI_MAXFREQUENCY);
+}
+
+/****************************************************************************
+ * Name: apa102_write32
+ *
+ * Description:
+ *   Write 32-bit to APA102
+ *
+ ****************************************************************************/
+
+static inline void apa102_write32(FAR struct apa102_dev_s *priv,
+                                  FAR uint32_t value)
+{
+  /* If SPI bus is shared then lock and configure it */
+
+  SPI_LOCK(priv->spi, true);
+
+  /* Note: APA102 doesn't use chip select */
+
+  /* Send 32 bits (4 bytes) */
+
+  SPI_SEND(priv->spi, (value & 0xff));
+  SPI_SEND(priv->spi, ((value & 0xff00) >> 8));
+  SPI_SEND(priv->spi, ((value & 0xff0000) >> 16));
+  SPI_SEND(priv->spi, ((value & 0xff000000) >> 24));
+
+  /* Unlock bus */
+
+  SPI_LOCK(priv->spi, false);
+}
+
+/****************************************************************************
+ * Name:  apa102_putrun
+ *
+ * Description:
+ *   This method can be used to write a partial raster line to the LCD:
+ *
+ *   dev     - The lcd device
+ *   row     - Starting row to write to (range: 0 <= row < yres)
+ *   col     - Starting column to write to (range: 0 <= col <= xres-npixels)
+ *   buffer  - The buffer containing the run to be written to the LCD
+ *   npixels - The number of pixels to write to the LCD
+ *             (range: 0 < npixels <= xres-col)
+ *
+ ****************************************************************************/
+
+static int apa102_putrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                          fb_coord_t col, FAR const uint8_t *buffer,
+                          size_t npixels)
+{
+  /* Because of this line of code, we will only be able to support a single
+   * APA102 device .
+   */
+
+  FAR struct apa102_dev_s *priv = (FAR struct apa102_dev_s *)dev;
+  int i;
+  int pixlen;
+
+  ginfo("row: %d col: %d npixels: %d\n", row, col, npixels);
+  DEBUGASSERT(buffer && ((uintptr_t)buffer & 1) == 0);
+
+  /* Clip the run to the display */
+
+  pixlen = npixels;
+  if ((unsigned int)col + (unsigned int)pixlen > (unsigned int)APA102_XRES)
+    {
+      pixlen = (int)APA102_XRES - (int)col;
+    }
+
+  /* Verify that some portion of the run remains on the display */
+
+  if (pixlen <= 0 || row > APA102_YRES)
+    {
+      return OK;
+    }
+
+  /* Convert rgb565 to APA102 LED values */
+
+  for (i = 0; i < pixlen; i++)
+    {
+      uint16_t *ptr = (uint16_t *)buffer;
+
+      priv->fb[(row * APA102_XRES) + col + i] = rgb565_apa102(*ptr++);
+    }
+
+  /* Confirm that SPI is configured correctly */
+
+  apa102_configspi(priv->spi);
+
+  /* Send a start of frame */
+
+  apa102_write32(priv, APA102_START_FRAME);
+
+  /* Send all LEDs values in the matrix */
+
+  for (i = 0; i < (APA102_XRES * APA102_YRES); i++)
+    {
+      uint32_t *led = (uint32_t *) &priv->fb[i];
+
+      /* Then transfer 4 bytes per LED */
+
+      apa102_write32(priv, (uint32_t) (*led | APA102_HEADER_FRAME));
+    }
+
+  /* Send an end of frame */
+
+  apa102_write32(priv, APA102_END_FRAME);
+
+  for (i = 0; i < (1 + APA102_XRES * APA102_YRES / 32); i++)
+    {
+      apa102_write32(priv, 0);
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getrun
+ *
+ * Description:
+ *   This method can be used to read a partial raster line from the LCD:
+ *
+ *  dev     - The lcd device
+ *  row     - Starting row to read from (range: 0 <= row < yres)
+ *  col     - Starting column to read read (range: 0 <= col <= xres-npixels)
+ *  buffer  - The buffer in which to return the run read from the LCD
+ *  npixels - The number of pixels to read from the LCD
+ *            (range: 0 < npixels <= xres-col)
+ *
+ ****************************************************************************/
+
+static int apa102_getrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                          fb_coord_t col, FAR uint8_t *buffer,
+                          size_t npixels)
+{
+  /* Because of this line of code, we will only be able to support a single
+   * APA102 device.
+   */
+
+  FAR struct apa102_dev_s *priv = (FAR struct apa102_dev_s *)dev;
+  int i;
+  int pixlen;
+
+  ginfo("row: %d col: %d npixels: %d\n", row, col, npixels);
+  DEBUGASSERT(buffer);
+
+  /* Clip the run to the display */
+
+  pixlen = npixels;
+  if ((unsigned int)col + (unsigned int)pixlen > (unsigned int)APA102_XRES)
+    {
+      pixlen = (int)APA102_XRES - (int)col;
+    }
+
+  /* Verify that some portion of the run is actually the display */
+
+  if (pixlen <= 0 || row > APA102_YRES)
+    {
+      return -EINVAL;
+    }
+
+  for (i = 0; i < pixlen; i++)
+    {
+      uint16_t *ptr = (uint16_t *) buffer;
+
+      *ptr++ = apa102_rgb565(priv->fb[(row * APA102_XRES) + col + i]);
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getvideoinfo
+ *
+ * Description:
+ *   Get information about the LCD video controller configuration.
+ *
+ ****************************************************************************/
+
+static int apa102_getvideoinfo(FAR struct lcd_dev_s *dev,
+                              FAR struct fb_videoinfo_s *vinfo)
+{
+  DEBUGASSERT(dev && vinfo);
+
+  ginfo("fmt: %d xres: %d yres: %d nplanes: %d\n",
+        g_videoinfo.fmt, g_videoinfo.xres, g_videoinfo.yres,
+        g_videoinfo.nplanes);
+
+  memcpy(vinfo, &g_videoinfo, sizeof(struct fb_videoinfo_s));
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getplaneinfo
+ *
+ * Description:
+ *   Get information about the configuration of each LCD color plane.
+ *
+ ****************************************************************************/
+
+static int apa102_getplaneinfo(FAR struct lcd_dev_s *dev,
+                                unsigned int planeno,
+                                FAR struct lcd_planeinfo_s *pinfo)
+{
+  DEBUGASSERT(dev && pinfo && planeno == 0);
+
+  ginfo("planeno: %d bpp: %d\n", planeno, g_planeinfo.bpp);
+
+  memcpy(pinfo, &g_planeinfo, sizeof(struct lcd_planeinfo_s));
+  pinfo->dev = dev;
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getpower
+ *
+ * Description:
+ *   Get the LCD panel power status (0: full off - CONFIG_LCD_MAXPOWER: full
+ *   on). On backlit LCDs, this setting may correspond to the backlight
+ *   setting.
+ *
+ ****************************************************************************/
+
+static int apa102_getpower(struct lcd_dev_s *dev)
+{
+  struct apa102_dev_s *priv = (struct apa102_dev_s *)dev;
+
+  DEBUGASSERT(priv);
+  ginfo("powered: %d\n", priv->powered);
+
+  return priv->powered;
+}
+
+/****************************************************************************
+ * Name:  apa102_setpower
+ *
+ * Description:
+ *   Enable/disable LCD panel power (0: full off - CONFIG_LCD_MAXPOWER: full
+ *   on). On backlit LCDs, this setting may correspond to the backlight
+ *   setting.
+ *
+ ****************************************************************************/
+
+static int apa102_setpower(struct lcd_dev_s *dev, int power)
+{
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getcontrast
+ *
+ * Description:
+ *   Get the current contrast setting (0-CONFIG_LCD_MAXCONTRAST).
+ *
+ ****************************************************************************/
+
+static int apa102_getcontrast(struct lcd_dev_s *dev)
+{
+  struct apa102_dev_s *priv = (struct apa102_dev_s *)dev;
+
+  DEBUGASSERT(priv);
+  return (int)priv->contrast;
+}
+
+/****************************************************************************
+ * Name:  apa102_setcontrast
+ *
+ * Description:
+ *   Set LCD panel contrast (0-CONFIG_LCD_MAXCONTRAST).
+ *
+ ****************************************************************************/
+
+static int apa102_setcontrast(struct lcd_dev_s *dev, unsigned int contrast)

Review Comment:
   ```suggestion
   static int apa102_setcontrast(FAR struct lcd_dev_s *dev, unsigned int contrast)
   ```



##########
include/nuttx/lcd/apa102.h:
##########
@@ -0,0 +1,89 @@
+/****************************************************************************
+ * include/nuttx/lcd/apa102.h
+ *
+ * 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.
+ *
+ ****************************************************************************/
+
+#ifndef __INCLUDE_NUTTX_LCD_APA102_H
+#define __INCLUDE_NUTTX_LCD_APA102_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/fs/ioctl.h>
+
+/* Configuration
+ * CONFIG_SPI - Enables support for SPI drivers
+ * CONFIG_LCD_APA102 - Enables support for the APA102 driver
+ */
+
+#if defined(CONFIG_SPI) && defined(CONFIG_LCD_APA102)
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Some important "colors" */
+
+#define APA102_BLACK         0
+#define APA102_WHITE         1
+
+/* Only two power settings are supported: */
+
+#define APA102_POWER_OFF     0
+#define APA102_POWER_ON      1
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Name: apa102_initialize
+ *
+ * Description:
+ *   Initialize the APA102 device as a LCD interface.
+ *
+ * Input Parameters:
+ *   spi   - An instance of the SPI interface to use to communicate
+ *           with the APA102.
+ *   devno - Device number to identify current display.
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno value on failure.
+ *
+ ****************************************************************************/
+
+FAR struct lcd_dev_s *apa102_initialize(FAR struct spi_dev_s *spi,
+                                         unsigned int devno);

Review Comment:
   ```suggestion
   FAR struct lcd_dev_s *apa102_initialize(FAR struct spi_dev_s *spi,
                                           unsigned int devno);
   ```



##########
drivers/lcd/apa102.c:
##########
@@ -0,0 +1,667 @@
+/****************************************************************************
+ * drivers/lcd/apa102.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.
+ *
+ ****************************************************************************/
+
+/* Driver to create a display using RBG LEDs APA102 chained together */
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/spi/spi.h>
+#include <nuttx/lcd/lcd.h>
+#include <nuttx/lcd/apa102.h>
+#include <nuttx/leds/apa102.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define MAX(a,b)    ((a)>(b)?(a):(b))
+
+/* Configuration ************************************************************/
+
+/* APA102 Configuration Settings:
+ *
+ * CONFIG_APA102_XRES - Specifies the number of physical
+ *   APA102 devices that are connected together horizontally.
+ *
+ * CONFIG_APA102_YRES - Specifies the number of physical
+ *   APA102 devices that are connected together vertically.
+ *
+ * CONFIG_LCD_INTENSITY - Defines the default bright of LEDs.
+ *
+ * Required LCD driver settings:
+ * CONFIG_LCD_APA102 - Enable APA102 support
+ *
+ */
+
+/* Verify that all configuration requirements have been met */
+
+/* SPI frequency */
+
+#ifndef CONFIG_APA102_FREQUENCY
+#  define CONFIG_APA102_FREQUENCY 10000000
+#endif
+
+/* APA102_COLUMNS determines the number of physical LEDs
+ * matrices that are used connected horizontally.
+ */
+
+#ifndef CONFIG_APA102_XRES
+#  define CONFIG_APA102_XRES 16
+#endif
+
+/* APA102_LINES determines the number of physical LEDs
+ * matrices that are used connected vertically.
+ */
+
+#ifndef CONFIG_APA102_YRES
+#  define CONFIG_APA102_YRES 16
+#endif
+
+/* Check contrast selection */
+
+#if !defined(CONFIG_LCD_MAXCONTRAST)
+#  define CONFIG_LCD_MAXCONTRAST 1
+#endif
+
+/* Color Properties *********************************************************/
+
+/* Display Resolution */
+
+#define APA102_XRES         CONFIG_APA102_XRES
+#define APA102_YRES         CONFIG_APA102_YRES
+
+/* Color depth and format */
+
+#define APA102_BPP          16
+#define APA102_COLORFMT     FB_FMT_RGB16_565
+
+#define APA102_LUT_SIZE     MAX(APA102_XRES, APA102_YRES)
+
+/* The size of the shadow frame buffer (4 bytes per LED) */
+
+#define APA102_FBSIZE       (APA102_XRES * APA102_YRES)
+
+/* LCD RGB Mapping */
+
+#ifdef CONFIG_FB_CMAP
+#  error "RGB color mapping not supported by this driver"
+#endif
+
+/* Cursor Controls */
+
+#ifdef CONFIG_FB_HWCURSOR
+#  error "Cursor control not supported by this driver"
+#endif
+
+/****************************************************************************
+ * Private Type Definition
+ ****************************************************************************/
+
+/* This structure describes the state of this driver */
+
+struct apa102_dev_s
+{
+  /* Publicly visible device structure */
+
+  struct lcd_dev_s dev;
+
+  /* Private LCD-specific information follows */
+
+  FAR struct spi_dev_s *spi;
+  uint8_t contrast;
+  uint8_t powered;
+
+  /* We need to send all the APA102 matrix screen once.
+   * So, create a framebuffer to save it in memory
+   */
+
+  struct apa102_ledstrip_s fb[APA102_FBSIZE];
+};
+
+/****************************************************************************
+ * Private Function Protototypes
+ ****************************************************************************/
+
+/* LCD Data Transfer Methods */
+
+static int apa102_putrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR const uint8_t *buffer,
+                         size_t npixels);
+static int apa102_getrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR uint8_t *buffer,
+                         size_t npixels);
+
+/* LCD Configuration */
+
+static int apa102_getvideoinfo(FAR struct lcd_dev_s *dev,
+                               FAR struct fb_videoinfo_s *vinfo);
+static int apa102_getplaneinfo(FAR struct lcd_dev_s *dev,
+                               unsigned int planeno,
+                               FAR struct lcd_planeinfo_s *pinfo);
+
+/* LCD Specific Controls */
+
+static int apa102_getpower(FAR struct lcd_dev_s *dev);
+static int apa102_setpower(FAR struct lcd_dev_s *dev, int power);
+static int apa102_getcontrast(FAR struct lcd_dev_s *dev);
+static int apa102_setcontrast(FAR struct lcd_dev_s *dev,
+                               unsigned int contrast);
+
+/* Initialization */
+
+static inline void up_clear(FAR struct apa102_dev_s  *priv);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* This is working memory allocated by the LCD driver for each LCD device
+ * and for each color plane.  This memory will hold one raster line of data.
+ * The size of the allocated run buffer must therefore be at least
+ * (bpp * xres / 8).  Actual alignment of the buffer must conform to the
+ * bitwidth of the underlying pixel type.
+ *
+ * If there are multiple planes, they may share the same working buffer
+ * because different planes will not be operate on concurrently.  However,
+ * if there are multiple LCD devices, they must each have unique run buffers.
+ */
+
+static uint8_t g_runbuffer[APA102_LUT_SIZE];
+
+/* This structure describes the overall LCD video controller */
+
+static const struct fb_videoinfo_s g_videoinfo =
+{
+  APA102_COLORFMT,    /* Color format: RGB16-565: RRRR RGGG GGGB BBBB */
+  APA102_XRES,        /* Horizontal resolution in pixel columns */
+  APA102_YRES,        /* Vertical resolution in pixel rows */
+  1,                  /* Number of color planes supported */
+};
+
+/* This is the standard, NuttX Plane information object */
+
+static const struct lcd_planeinfo_s g_planeinfo =
+{
+  .putrun = apa102_putrun,              /* Put a run into LCD memory */
+  .getrun = apa102_getrun,              /* Get a run from LCD memory */
+  .buffer = (FAR uint8_t *)g_runbuffer, /* Run scratch buffer */
+  .bpp    = APA102_BPP,                 /* Bits-per-pixel */
+};
+
+/* This is the standard, NuttX LCD driver object */
+
+static struct apa102_dev_s g_apa102dev =
+{
+  /* struct lcd_dev_s */
+
+  {
+    /* LCD Configuration */
+
+    apa102_getvideoinfo,
+    apa102_getplaneinfo,
+
+#ifdef CONFIG_FB_CMAP
+    /* LCD RGB Mapping -- Not supported */
+
+    NULL,
+    NULL,
+#endif
+
+#ifdef CONFIG_FB_HWCURSOR
+    /* Cursor Controls -- Not supported */
+
+    NULL,
+    NULL,
+#endif
+
+    /* LCD Specific Controls */
+
+    apa102_getpower,
+    apa102_setpower,
+    apa102_getcontrast,
+    apa102_setcontrast,
+  },
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: rgb565_apa102
+ *
+ * Description:
+ *   Convert RGB565 to APA102 RGB888 format
+ *
+ ****************************************************************************/
+
+static struct apa102_ledstrip_s rgb565_apa102(uint16_t rgb565)
+{
+  struct apa102_ledstrip_s led;
+  led.red    = (rgb565 & 0b1111100000000000) >> 8;
+  led.green  = (rgb565 & 0b11111100000) >> 3;
+  led.blue   = (rgb565 & 0b11111) << 3;
+  led.bright = 0;
+  return led;
+}
+
+/****************************************************************************
+ * Name: apa102_rgb565
+ *
+ * Description:
+ *   Convert APA102 RGB888 to RGB565 format
+ *
+ ****************************************************************************/
+
+static uint16_t apa102_rgb565(struct apa102_ledstrip_s led)
+{
+  uint16_t pixel;
+
+  pixel  = (led.red & 0b11111000) << 8;
+  pixel |= (led.green & 0b11111100) << 3;
+  pixel |= (led.blue & 0b11111000) >> 3;
+  return pixel;
+}
+
+/****************************************************************************
+ * Name: apa102_configspi
+ *
+ * Description:
+ *   Set the SPI bus configuration
+ *
+ ****************************************************************************/
+
+static inline void apa102_configspi(FAR struct spi_dev_s *spi)
+{
+  /* Configure SPI for the APA102 */
+
+  SPI_SETMODE(spi, SPIDEV_MODE0);
+  SPI_SETBITS(spi, 8);
+  SPI_HWFEATURES(spi, 0);
+  SPI_SETFREQUENCY(spi, APA102_SPI_MAXFREQUENCY);
+}
+
+/****************************************************************************
+ * Name: apa102_write32
+ *
+ * Description:
+ *   Write 32-bit to APA102
+ *
+ ****************************************************************************/
+
+static inline void apa102_write32(FAR struct apa102_dev_s *priv,
+                                  FAR uint32_t value)
+{
+  /* If SPI bus is shared then lock and configure it */
+
+  SPI_LOCK(priv->spi, true);
+
+  /* Note: APA102 doesn't use chip select */
+
+  /* Send 32 bits (4 bytes) */
+
+  SPI_SEND(priv->spi, (value & 0xff));
+  SPI_SEND(priv->spi, ((value & 0xff00) >> 8));
+  SPI_SEND(priv->spi, ((value & 0xff0000) >> 16));
+  SPI_SEND(priv->spi, ((value & 0xff000000) >> 24));
+
+  /* Unlock bus */
+
+  SPI_LOCK(priv->spi, false);
+}
+
+/****************************************************************************
+ * Name:  apa102_putrun
+ *
+ * Description:
+ *   This method can be used to write a partial raster line to the LCD:
+ *
+ *   dev     - The lcd device
+ *   row     - Starting row to write to (range: 0 <= row < yres)
+ *   col     - Starting column to write to (range: 0 <= col <= xres-npixels)
+ *   buffer  - The buffer containing the run to be written to the LCD
+ *   npixels - The number of pixels to write to the LCD
+ *             (range: 0 < npixels <= xres-col)
+ *
+ ****************************************************************************/
+
+static int apa102_putrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                          fb_coord_t col, FAR const uint8_t *buffer,
+                          size_t npixels)
+{
+  /* Because of this line of code, we will only be able to support a single
+   * APA102 device .
+   */
+
+  FAR struct apa102_dev_s *priv = (FAR struct apa102_dev_s *)dev;
+  int i;
+  int pixlen;
+
+  ginfo("row: %d col: %d npixels: %d\n", row, col, npixels);
+  DEBUGASSERT(buffer && ((uintptr_t)buffer & 1) == 0);
+
+  /* Clip the run to the display */
+
+  pixlen = npixels;
+  if ((unsigned int)col + (unsigned int)pixlen > (unsigned int)APA102_XRES)
+    {
+      pixlen = (int)APA102_XRES - (int)col;
+    }
+
+  /* Verify that some portion of the run remains on the display */
+
+  if (pixlen <= 0 || row > APA102_YRES)
+    {
+      return OK;
+    }
+
+  /* Convert rgb565 to APA102 LED values */
+
+  for (i = 0; i < pixlen; i++)
+    {
+      uint16_t *ptr = (uint16_t *)buffer;
+
+      priv->fb[(row * APA102_XRES) + col + i] = rgb565_apa102(*ptr++);
+    }
+
+  /* Confirm that SPI is configured correctly */
+
+  apa102_configspi(priv->spi);
+
+  /* Send a start of frame */
+
+  apa102_write32(priv, APA102_START_FRAME);
+
+  /* Send all LEDs values in the matrix */
+
+  for (i = 0; i < (APA102_XRES * APA102_YRES); i++)
+    {
+      uint32_t *led = (uint32_t *) &priv->fb[i];
+
+      /* Then transfer 4 bytes per LED */
+
+      apa102_write32(priv, (uint32_t) (*led | APA102_HEADER_FRAME));
+    }
+
+  /* Send an end of frame */
+
+  apa102_write32(priv, APA102_END_FRAME);
+
+  for (i = 0; i < (1 + APA102_XRES * APA102_YRES / 32); i++)
+    {
+      apa102_write32(priv, 0);
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getrun
+ *
+ * Description:
+ *   This method can be used to read a partial raster line from the LCD:
+ *
+ *  dev     - The lcd device
+ *  row     - Starting row to read from (range: 0 <= row < yres)
+ *  col     - Starting column to read read (range: 0 <= col <= xres-npixels)
+ *  buffer  - The buffer in which to return the run read from the LCD
+ *  npixels - The number of pixels to read from the LCD
+ *            (range: 0 < npixels <= xres-col)
+ *
+ ****************************************************************************/
+
+static int apa102_getrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                          fb_coord_t col, FAR uint8_t *buffer,
+                          size_t npixels)
+{
+  /* Because of this line of code, we will only be able to support a single
+   * APA102 device.
+   */
+
+  FAR struct apa102_dev_s *priv = (FAR struct apa102_dev_s *)dev;
+  int i;
+  int pixlen;
+
+  ginfo("row: %d col: %d npixels: %d\n", row, col, npixels);
+  DEBUGASSERT(buffer);
+
+  /* Clip the run to the display */
+
+  pixlen = npixels;
+  if ((unsigned int)col + (unsigned int)pixlen > (unsigned int)APA102_XRES)
+    {
+      pixlen = (int)APA102_XRES - (int)col;
+    }
+
+  /* Verify that some portion of the run is actually the display */
+
+  if (pixlen <= 0 || row > APA102_YRES)
+    {
+      return -EINVAL;
+    }
+
+  for (i = 0; i < pixlen; i++)
+    {
+      uint16_t *ptr = (uint16_t *) buffer;
+
+      *ptr++ = apa102_rgb565(priv->fb[(row * APA102_XRES) + col + i]);
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getvideoinfo
+ *
+ * Description:
+ *   Get information about the LCD video controller configuration.
+ *
+ ****************************************************************************/
+
+static int apa102_getvideoinfo(FAR struct lcd_dev_s *dev,
+                              FAR struct fb_videoinfo_s *vinfo)

Review Comment:
   ```suggestion
   static int apa102_getvideoinfo(FAR struct lcd_dev_s *dev,
                                  FAR struct fb_videoinfo_s *vinfo)
   ```



##########
drivers/lcd/apa102.c:
##########
@@ -0,0 +1,667 @@
+/****************************************************************************
+ * drivers/lcd/apa102.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.
+ *
+ ****************************************************************************/
+
+/* Driver to create a display using RBG LEDs APA102 chained together */
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/spi/spi.h>
+#include <nuttx/lcd/lcd.h>
+#include <nuttx/lcd/apa102.h>
+#include <nuttx/leds/apa102.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define MAX(a,b)    ((a)>(b)?(a):(b))
+
+/* Configuration ************************************************************/
+
+/* APA102 Configuration Settings:
+ *
+ * CONFIG_APA102_XRES - Specifies the number of physical
+ *   APA102 devices that are connected together horizontally.
+ *
+ * CONFIG_APA102_YRES - Specifies the number of physical
+ *   APA102 devices that are connected together vertically.
+ *
+ * CONFIG_LCD_INTENSITY - Defines the default bright of LEDs.
+ *
+ * Required LCD driver settings:
+ * CONFIG_LCD_APA102 - Enable APA102 support
+ *
+ */
+
+/* Verify that all configuration requirements have been met */
+
+/* SPI frequency */
+
+#ifndef CONFIG_APA102_FREQUENCY
+#  define CONFIG_APA102_FREQUENCY 10000000
+#endif
+
+/* APA102_COLUMNS determines the number of physical LEDs
+ * matrices that are used connected horizontally.
+ */
+
+#ifndef CONFIG_APA102_XRES
+#  define CONFIG_APA102_XRES 16
+#endif
+
+/* APA102_LINES determines the number of physical LEDs
+ * matrices that are used connected vertically.
+ */
+
+#ifndef CONFIG_APA102_YRES
+#  define CONFIG_APA102_YRES 16
+#endif
+
+/* Check contrast selection */
+
+#if !defined(CONFIG_LCD_MAXCONTRAST)
+#  define CONFIG_LCD_MAXCONTRAST 1
+#endif
+
+/* Color Properties *********************************************************/
+
+/* Display Resolution */
+
+#define APA102_XRES         CONFIG_APA102_XRES
+#define APA102_YRES         CONFIG_APA102_YRES
+
+/* Color depth and format */
+
+#define APA102_BPP          16
+#define APA102_COLORFMT     FB_FMT_RGB16_565
+
+#define APA102_LUT_SIZE     MAX(APA102_XRES, APA102_YRES)
+
+/* The size of the shadow frame buffer (4 bytes per LED) */
+
+#define APA102_FBSIZE       (APA102_XRES * APA102_YRES)
+
+/* LCD RGB Mapping */
+
+#ifdef CONFIG_FB_CMAP
+#  error "RGB color mapping not supported by this driver"
+#endif
+
+/* Cursor Controls */
+
+#ifdef CONFIG_FB_HWCURSOR
+#  error "Cursor control not supported by this driver"
+#endif
+
+/****************************************************************************
+ * Private Type Definition
+ ****************************************************************************/
+
+/* This structure describes the state of this driver */
+
+struct apa102_dev_s
+{
+  /* Publicly visible device structure */
+
+  struct lcd_dev_s dev;
+
+  /* Private LCD-specific information follows */
+
+  FAR struct spi_dev_s *spi;
+  uint8_t contrast;
+  uint8_t powered;
+
+  /* We need to send all the APA102 matrix screen once.
+   * So, create a framebuffer to save it in memory
+   */
+
+  struct apa102_ledstrip_s fb[APA102_FBSIZE];
+};
+
+/****************************************************************************
+ * Private Function Protototypes
+ ****************************************************************************/
+
+/* LCD Data Transfer Methods */
+
+static int apa102_putrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR const uint8_t *buffer,
+                         size_t npixels);
+static int apa102_getrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR uint8_t *buffer,
+                         size_t npixels);
+
+/* LCD Configuration */
+
+static int apa102_getvideoinfo(FAR struct lcd_dev_s *dev,
+                               FAR struct fb_videoinfo_s *vinfo);
+static int apa102_getplaneinfo(FAR struct lcd_dev_s *dev,
+                               unsigned int planeno,
+                               FAR struct lcd_planeinfo_s *pinfo);
+
+/* LCD Specific Controls */
+
+static int apa102_getpower(FAR struct lcd_dev_s *dev);
+static int apa102_setpower(FAR struct lcd_dev_s *dev, int power);
+static int apa102_getcontrast(FAR struct lcd_dev_s *dev);
+static int apa102_setcontrast(FAR struct lcd_dev_s *dev,
+                               unsigned int contrast);
+
+/* Initialization */
+
+static inline void up_clear(FAR struct apa102_dev_s  *priv);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* This is working memory allocated by the LCD driver for each LCD device
+ * and for each color plane.  This memory will hold one raster line of data.
+ * The size of the allocated run buffer must therefore be at least
+ * (bpp * xres / 8).  Actual alignment of the buffer must conform to the
+ * bitwidth of the underlying pixel type.
+ *
+ * If there are multiple planes, they may share the same working buffer
+ * because different planes will not be operate on concurrently.  However,
+ * if there are multiple LCD devices, they must each have unique run buffers.
+ */
+
+static uint8_t g_runbuffer[APA102_LUT_SIZE];
+
+/* This structure describes the overall LCD video controller */
+
+static const struct fb_videoinfo_s g_videoinfo =
+{
+  APA102_COLORFMT,    /* Color format: RGB16-565: RRRR RGGG GGGB BBBB */
+  APA102_XRES,        /* Horizontal resolution in pixel columns */
+  APA102_YRES,        /* Vertical resolution in pixel rows */
+  1,                  /* Number of color planes supported */
+};
+
+/* This is the standard, NuttX Plane information object */
+
+static const struct lcd_planeinfo_s g_planeinfo =
+{
+  .putrun = apa102_putrun,              /* Put a run into LCD memory */
+  .getrun = apa102_getrun,              /* Get a run from LCD memory */
+  .buffer = (FAR uint8_t *)g_runbuffer, /* Run scratch buffer */
+  .bpp    = APA102_BPP,                 /* Bits-per-pixel */
+};
+
+/* This is the standard, NuttX LCD driver object */
+
+static struct apa102_dev_s g_apa102dev =
+{
+  /* struct lcd_dev_s */
+
+  {
+    /* LCD Configuration */
+
+    apa102_getvideoinfo,
+    apa102_getplaneinfo,
+
+#ifdef CONFIG_FB_CMAP
+    /* LCD RGB Mapping -- Not supported */
+
+    NULL,
+    NULL,
+#endif
+
+#ifdef CONFIG_FB_HWCURSOR
+    /* Cursor Controls -- Not supported */
+
+    NULL,
+    NULL,
+#endif
+
+    /* LCD Specific Controls */
+
+    apa102_getpower,
+    apa102_setpower,
+    apa102_getcontrast,
+    apa102_setcontrast,
+  },
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: rgb565_apa102
+ *
+ * Description:
+ *   Convert RGB565 to APA102 RGB888 format
+ *
+ ****************************************************************************/
+
+static struct apa102_ledstrip_s rgb565_apa102(uint16_t rgb565)
+{
+  struct apa102_ledstrip_s led;
+  led.red    = (rgb565 & 0b1111100000000000) >> 8;

Review Comment:
   ```suggestion
     struct apa102_ledstrip_s led;
   
     led.red    = (rgb565 & 0b1111100000000000) >> 8;
   ```



##########
drivers/lcd/apa102.c:
##########
@@ -0,0 +1,667 @@
+/****************************************************************************
+ * drivers/lcd/apa102.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.
+ *
+ ****************************************************************************/
+
+/* Driver to create a display using RBG LEDs APA102 chained together */
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/spi/spi.h>
+#include <nuttx/lcd/lcd.h>
+#include <nuttx/lcd/apa102.h>
+#include <nuttx/leds/apa102.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define MAX(a,b)    ((a)>(b)?(a):(b))
+
+/* Configuration ************************************************************/
+
+/* APA102 Configuration Settings:
+ *
+ * CONFIG_APA102_XRES - Specifies the number of physical
+ *   APA102 devices that are connected together horizontally.
+ *
+ * CONFIG_APA102_YRES - Specifies the number of physical
+ *   APA102 devices that are connected together vertically.
+ *
+ * CONFIG_LCD_INTENSITY - Defines the default bright of LEDs.
+ *
+ * Required LCD driver settings:
+ * CONFIG_LCD_APA102 - Enable APA102 support
+ *
+ */
+
+/* Verify that all configuration requirements have been met */
+
+/* SPI frequency */
+
+#ifndef CONFIG_APA102_FREQUENCY
+#  define CONFIG_APA102_FREQUENCY 10000000
+#endif
+
+/* APA102_COLUMNS determines the number of physical LEDs
+ * matrices that are used connected horizontally.
+ */
+
+#ifndef CONFIG_APA102_XRES
+#  define CONFIG_APA102_XRES 16
+#endif
+
+/* APA102_LINES determines the number of physical LEDs
+ * matrices that are used connected vertically.
+ */
+
+#ifndef CONFIG_APA102_YRES
+#  define CONFIG_APA102_YRES 16
+#endif
+
+/* Check contrast selection */
+
+#if !defined(CONFIG_LCD_MAXCONTRAST)
+#  define CONFIG_LCD_MAXCONTRAST 1
+#endif
+
+/* Color Properties *********************************************************/
+
+/* Display Resolution */
+
+#define APA102_XRES         CONFIG_APA102_XRES
+#define APA102_YRES         CONFIG_APA102_YRES
+
+/* Color depth and format */
+
+#define APA102_BPP          16
+#define APA102_COLORFMT     FB_FMT_RGB16_565
+
+#define APA102_LUT_SIZE     MAX(APA102_XRES, APA102_YRES)
+
+/* The size of the shadow frame buffer (4 bytes per LED) */
+
+#define APA102_FBSIZE       (APA102_XRES * APA102_YRES)
+
+/* LCD RGB Mapping */
+
+#ifdef CONFIG_FB_CMAP
+#  error "RGB color mapping not supported by this driver"
+#endif
+
+/* Cursor Controls */
+
+#ifdef CONFIG_FB_HWCURSOR
+#  error "Cursor control not supported by this driver"
+#endif
+
+/****************************************************************************
+ * Private Type Definition
+ ****************************************************************************/
+
+/* This structure describes the state of this driver */
+
+struct apa102_dev_s
+{
+  /* Publicly visible device structure */
+
+  struct lcd_dev_s dev;
+
+  /* Private LCD-specific information follows */
+
+  FAR struct spi_dev_s *spi;
+  uint8_t contrast;
+  uint8_t powered;
+
+  /* We need to send all the APA102 matrix screen once.
+   * So, create a framebuffer to save it in memory
+   */
+
+  struct apa102_ledstrip_s fb[APA102_FBSIZE];
+};
+
+/****************************************************************************
+ * Private Function Protototypes
+ ****************************************************************************/
+
+/* LCD Data Transfer Methods */
+
+static int apa102_putrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR const uint8_t *buffer,
+                         size_t npixels);
+static int apa102_getrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR uint8_t *buffer,
+                         size_t npixels);
+
+/* LCD Configuration */
+
+static int apa102_getvideoinfo(FAR struct lcd_dev_s *dev,
+                               FAR struct fb_videoinfo_s *vinfo);
+static int apa102_getplaneinfo(FAR struct lcd_dev_s *dev,
+                               unsigned int planeno,
+                               FAR struct lcd_planeinfo_s *pinfo);
+
+/* LCD Specific Controls */
+
+static int apa102_getpower(FAR struct lcd_dev_s *dev);
+static int apa102_setpower(FAR struct lcd_dev_s *dev, int power);
+static int apa102_getcontrast(FAR struct lcd_dev_s *dev);
+static int apa102_setcontrast(FAR struct lcd_dev_s *dev,
+                               unsigned int contrast);
+
+/* Initialization */
+
+static inline void up_clear(FAR struct apa102_dev_s  *priv);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* This is working memory allocated by the LCD driver for each LCD device
+ * and for each color plane.  This memory will hold one raster line of data.
+ * The size of the allocated run buffer must therefore be at least
+ * (bpp * xres / 8).  Actual alignment of the buffer must conform to the
+ * bitwidth of the underlying pixel type.
+ *
+ * If there are multiple planes, they may share the same working buffer
+ * because different planes will not be operate on concurrently.  However,
+ * if there are multiple LCD devices, they must each have unique run buffers.
+ */
+
+static uint8_t g_runbuffer[APA102_LUT_SIZE];
+
+/* This structure describes the overall LCD video controller */
+
+static const struct fb_videoinfo_s g_videoinfo =
+{
+  APA102_COLORFMT,    /* Color format: RGB16-565: RRRR RGGG GGGB BBBB */
+  APA102_XRES,        /* Horizontal resolution in pixel columns */
+  APA102_YRES,        /* Vertical resolution in pixel rows */
+  1,                  /* Number of color planes supported */
+};
+
+/* This is the standard, NuttX Plane information object */
+
+static const struct lcd_planeinfo_s g_planeinfo =
+{
+  .putrun = apa102_putrun,              /* Put a run into LCD memory */
+  .getrun = apa102_getrun,              /* Get a run from LCD memory */
+  .buffer = (FAR uint8_t *)g_runbuffer, /* Run scratch buffer */
+  .bpp    = APA102_BPP,                 /* Bits-per-pixel */
+};
+
+/* This is the standard, NuttX LCD driver object */
+
+static struct apa102_dev_s g_apa102dev =
+{
+  /* struct lcd_dev_s */
+
+  {
+    /* LCD Configuration */
+
+    apa102_getvideoinfo,
+    apa102_getplaneinfo,
+
+#ifdef CONFIG_FB_CMAP
+    /* LCD RGB Mapping -- Not supported */
+
+    NULL,
+    NULL,
+#endif
+
+#ifdef CONFIG_FB_HWCURSOR
+    /* Cursor Controls -- Not supported */
+
+    NULL,
+    NULL,
+#endif
+
+    /* LCD Specific Controls */
+
+    apa102_getpower,
+    apa102_setpower,
+    apa102_getcontrast,
+    apa102_setcontrast,
+  },
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: rgb565_apa102
+ *
+ * Description:
+ *   Convert RGB565 to APA102 RGB888 format
+ *
+ ****************************************************************************/
+
+static struct apa102_ledstrip_s rgb565_apa102(uint16_t rgb565)
+{
+  struct apa102_ledstrip_s led;
+  led.red    = (rgb565 & 0b1111100000000000) >> 8;
+  led.green  = (rgb565 & 0b11111100000) >> 3;
+  led.blue   = (rgb565 & 0b11111) << 3;
+  led.bright = 0;
+  return led;
+}
+
+/****************************************************************************
+ * Name: apa102_rgb565
+ *
+ * Description:
+ *   Convert APA102 RGB888 to RGB565 format
+ *
+ ****************************************************************************/
+
+static uint16_t apa102_rgb565(struct apa102_ledstrip_s led)
+{
+  uint16_t pixel;
+
+  pixel  = (led.red & 0b11111000) << 8;
+  pixel |= (led.green & 0b11111100) << 3;
+  pixel |= (led.blue & 0b11111000) >> 3;
+  return pixel;
+}
+
+/****************************************************************************
+ * Name: apa102_configspi
+ *
+ * Description:
+ *   Set the SPI bus configuration
+ *
+ ****************************************************************************/
+
+static inline void apa102_configspi(FAR struct spi_dev_s *spi)
+{
+  /* Configure SPI for the APA102 */
+
+  SPI_SETMODE(spi, SPIDEV_MODE0);
+  SPI_SETBITS(spi, 8);
+  SPI_HWFEATURES(spi, 0);
+  SPI_SETFREQUENCY(spi, APA102_SPI_MAXFREQUENCY);
+}
+
+/****************************************************************************
+ * Name: apa102_write32
+ *
+ * Description:
+ *   Write 32-bit to APA102
+ *
+ ****************************************************************************/
+
+static inline void apa102_write32(FAR struct apa102_dev_s *priv,
+                                  FAR uint32_t value)

Review Comment:
   ```suggestion
                                     uint32_t value)
   ```



##########
drivers/lcd/apa102.c:
##########
@@ -0,0 +1,667 @@
+/****************************************************************************
+ * drivers/lcd/apa102.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.
+ *
+ ****************************************************************************/
+
+/* Driver to create a display using RBG LEDs APA102 chained together */
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/spi/spi.h>
+#include <nuttx/lcd/lcd.h>
+#include <nuttx/lcd/apa102.h>
+#include <nuttx/leds/apa102.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define MAX(a,b)    ((a)>(b)?(a):(b))
+
+/* Configuration ************************************************************/
+
+/* APA102 Configuration Settings:
+ *
+ * CONFIG_APA102_XRES - Specifies the number of physical
+ *   APA102 devices that are connected together horizontally.
+ *
+ * CONFIG_APA102_YRES - Specifies the number of physical
+ *   APA102 devices that are connected together vertically.
+ *
+ * CONFIG_LCD_INTENSITY - Defines the default bright of LEDs.
+ *
+ * Required LCD driver settings:
+ * CONFIG_LCD_APA102 - Enable APA102 support
+ *
+ */
+
+/* Verify that all configuration requirements have been met */
+
+/* SPI frequency */
+
+#ifndef CONFIG_APA102_FREQUENCY
+#  define CONFIG_APA102_FREQUENCY 10000000
+#endif
+
+/* APA102_COLUMNS determines the number of physical LEDs
+ * matrices that are used connected horizontally.
+ */
+
+#ifndef CONFIG_APA102_XRES
+#  define CONFIG_APA102_XRES 16
+#endif
+
+/* APA102_LINES determines the number of physical LEDs
+ * matrices that are used connected vertically.
+ */
+
+#ifndef CONFIG_APA102_YRES
+#  define CONFIG_APA102_YRES 16
+#endif
+
+/* Check contrast selection */
+
+#if !defined(CONFIG_LCD_MAXCONTRAST)
+#  define CONFIG_LCD_MAXCONTRAST 1
+#endif
+
+/* Color Properties *********************************************************/
+
+/* Display Resolution */
+
+#define APA102_XRES         CONFIG_APA102_XRES
+#define APA102_YRES         CONFIG_APA102_YRES
+
+/* Color depth and format */
+
+#define APA102_BPP          16
+#define APA102_COLORFMT     FB_FMT_RGB16_565
+
+#define APA102_LUT_SIZE     MAX(APA102_XRES, APA102_YRES)
+
+/* The size of the shadow frame buffer (4 bytes per LED) */
+
+#define APA102_FBSIZE       (APA102_XRES * APA102_YRES)
+
+/* LCD RGB Mapping */
+
+#ifdef CONFIG_FB_CMAP
+#  error "RGB color mapping not supported by this driver"
+#endif
+
+/* Cursor Controls */
+
+#ifdef CONFIG_FB_HWCURSOR
+#  error "Cursor control not supported by this driver"
+#endif
+
+/****************************************************************************
+ * Private Type Definition
+ ****************************************************************************/
+
+/* This structure describes the state of this driver */
+
+struct apa102_dev_s
+{
+  /* Publicly visible device structure */
+
+  struct lcd_dev_s dev;
+
+  /* Private LCD-specific information follows */
+
+  FAR struct spi_dev_s *spi;
+  uint8_t contrast;
+  uint8_t powered;
+
+  /* We need to send all the APA102 matrix screen once.
+   * So, create a framebuffer to save it in memory
+   */
+
+  struct apa102_ledstrip_s fb[APA102_FBSIZE];
+};
+
+/****************************************************************************
+ * Private Function Protototypes
+ ****************************************************************************/
+
+/* LCD Data Transfer Methods */
+
+static int apa102_putrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR const uint8_t *buffer,
+                         size_t npixels);
+static int apa102_getrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR uint8_t *buffer,
+                         size_t npixels);
+
+/* LCD Configuration */
+
+static int apa102_getvideoinfo(FAR struct lcd_dev_s *dev,
+                               FAR struct fb_videoinfo_s *vinfo);
+static int apa102_getplaneinfo(FAR struct lcd_dev_s *dev,
+                               unsigned int planeno,
+                               FAR struct lcd_planeinfo_s *pinfo);
+
+/* LCD Specific Controls */
+
+static int apa102_getpower(FAR struct lcd_dev_s *dev);
+static int apa102_setpower(FAR struct lcd_dev_s *dev, int power);
+static int apa102_getcontrast(FAR struct lcd_dev_s *dev);
+static int apa102_setcontrast(FAR struct lcd_dev_s *dev,
+                               unsigned int contrast);
+
+/* Initialization */
+
+static inline void up_clear(FAR struct apa102_dev_s  *priv);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* This is working memory allocated by the LCD driver for each LCD device
+ * and for each color plane.  This memory will hold one raster line of data.
+ * The size of the allocated run buffer must therefore be at least
+ * (bpp * xres / 8).  Actual alignment of the buffer must conform to the
+ * bitwidth of the underlying pixel type.
+ *
+ * If there are multiple planes, they may share the same working buffer
+ * because different planes will not be operate on concurrently.  However,
+ * if there are multiple LCD devices, they must each have unique run buffers.
+ */
+
+static uint8_t g_runbuffer[APA102_LUT_SIZE];
+
+/* This structure describes the overall LCD video controller */
+
+static const struct fb_videoinfo_s g_videoinfo =
+{
+  APA102_COLORFMT,    /* Color format: RGB16-565: RRRR RGGG GGGB BBBB */
+  APA102_XRES,        /* Horizontal resolution in pixel columns */
+  APA102_YRES,        /* Vertical resolution in pixel rows */
+  1,                  /* Number of color planes supported */
+};
+
+/* This is the standard, NuttX Plane information object */
+
+static const struct lcd_planeinfo_s g_planeinfo =
+{
+  .putrun = apa102_putrun,              /* Put a run into LCD memory */
+  .getrun = apa102_getrun,              /* Get a run from LCD memory */
+  .buffer = (FAR uint8_t *)g_runbuffer, /* Run scratch buffer */
+  .bpp    = APA102_BPP,                 /* Bits-per-pixel */
+};
+
+/* This is the standard, NuttX LCD driver object */
+
+static struct apa102_dev_s g_apa102dev =
+{
+  /* struct lcd_dev_s */
+
+  {
+    /* LCD Configuration */
+
+    apa102_getvideoinfo,
+    apa102_getplaneinfo,
+
+#ifdef CONFIG_FB_CMAP
+    /* LCD RGB Mapping -- Not supported */
+
+    NULL,
+    NULL,
+#endif
+
+#ifdef CONFIG_FB_HWCURSOR
+    /* Cursor Controls -- Not supported */
+
+    NULL,
+    NULL,
+#endif
+
+    /* LCD Specific Controls */
+
+    apa102_getpower,
+    apa102_setpower,
+    apa102_getcontrast,
+    apa102_setcontrast,
+  },
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: rgb565_apa102
+ *
+ * Description:
+ *   Convert RGB565 to APA102 RGB888 format
+ *
+ ****************************************************************************/
+
+static struct apa102_ledstrip_s rgb565_apa102(uint16_t rgb565)
+{
+  struct apa102_ledstrip_s led;
+  led.red    = (rgb565 & 0b1111100000000000) >> 8;
+  led.green  = (rgb565 & 0b11111100000) >> 3;
+  led.blue   = (rgb565 & 0b11111) << 3;
+  led.bright = 0;
+  return led;
+}
+
+/****************************************************************************
+ * Name: apa102_rgb565
+ *
+ * Description:
+ *   Convert APA102 RGB888 to RGB565 format
+ *
+ ****************************************************************************/
+
+static uint16_t apa102_rgb565(struct apa102_ledstrip_s led)
+{
+  uint16_t pixel;
+
+  pixel  = (led.red & 0b11111000) << 8;
+  pixel |= (led.green & 0b11111100) << 3;
+  pixel |= (led.blue & 0b11111000) >> 3;
+  return pixel;
+}
+
+/****************************************************************************
+ * Name: apa102_configspi
+ *
+ * Description:
+ *   Set the SPI bus configuration
+ *
+ ****************************************************************************/
+
+static inline void apa102_configspi(FAR struct spi_dev_s *spi)
+{
+  /* Configure SPI for the APA102 */
+
+  SPI_SETMODE(spi, SPIDEV_MODE0);
+  SPI_SETBITS(spi, 8);
+  SPI_HWFEATURES(spi, 0);
+  SPI_SETFREQUENCY(spi, APA102_SPI_MAXFREQUENCY);
+}
+
+/****************************************************************************
+ * Name: apa102_write32
+ *
+ * Description:
+ *   Write 32-bit to APA102
+ *
+ ****************************************************************************/
+
+static inline void apa102_write32(FAR struct apa102_dev_s *priv,
+                                  FAR uint32_t value)
+{
+  /* If SPI bus is shared then lock and configure it */
+
+  SPI_LOCK(priv->spi, true);
+
+  /* Note: APA102 doesn't use chip select */
+
+  /* Send 32 bits (4 bytes) */
+
+  SPI_SEND(priv->spi, (value & 0xff));
+  SPI_SEND(priv->spi, ((value & 0xff00) >> 8));
+  SPI_SEND(priv->spi, ((value & 0xff0000) >> 16));
+  SPI_SEND(priv->spi, ((value & 0xff000000) >> 24));
+
+  /* Unlock bus */
+
+  SPI_LOCK(priv->spi, false);
+}
+
+/****************************************************************************
+ * Name:  apa102_putrun
+ *
+ * Description:
+ *   This method can be used to write a partial raster line to the LCD:
+ *
+ *   dev     - The lcd device
+ *   row     - Starting row to write to (range: 0 <= row < yres)
+ *   col     - Starting column to write to (range: 0 <= col <= xres-npixels)
+ *   buffer  - The buffer containing the run to be written to the LCD
+ *   npixels - The number of pixels to write to the LCD
+ *             (range: 0 < npixels <= xres-col)
+ *
+ ****************************************************************************/
+
+static int apa102_putrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                          fb_coord_t col, FAR const uint8_t *buffer,
+                          size_t npixels)
+{
+  /* Because of this line of code, we will only be able to support a single
+   * APA102 device .
+   */
+
+  FAR struct apa102_dev_s *priv = (FAR struct apa102_dev_s *)dev;
+  int i;
+  int pixlen;
+
+  ginfo("row: %d col: %d npixels: %d\n", row, col, npixels);
+  DEBUGASSERT(buffer && ((uintptr_t)buffer & 1) == 0);
+
+  /* Clip the run to the display */
+
+  pixlen = npixels;
+  if ((unsigned int)col + (unsigned int)pixlen > (unsigned int)APA102_XRES)
+    {
+      pixlen = (int)APA102_XRES - (int)col;
+    }
+
+  /* Verify that some portion of the run remains on the display */
+
+  if (pixlen <= 0 || row > APA102_YRES)
+    {
+      return OK;
+    }
+
+  /* Convert rgb565 to APA102 LED values */
+
+  for (i = 0; i < pixlen; i++)
+    {
+      uint16_t *ptr = (uint16_t *)buffer;
+
+      priv->fb[(row * APA102_XRES) + col + i] = rgb565_apa102(*ptr++);
+    }
+
+  /* Confirm that SPI is configured correctly */
+
+  apa102_configspi(priv->spi);
+
+  /* Send a start of frame */
+
+  apa102_write32(priv, APA102_START_FRAME);
+
+  /* Send all LEDs values in the matrix */
+
+  for (i = 0; i < (APA102_XRES * APA102_YRES); i++)
+    {
+      uint32_t *led = (uint32_t *) &priv->fb[i];
+
+      /* Then transfer 4 bytes per LED */
+
+      apa102_write32(priv, (uint32_t) (*led | APA102_HEADER_FRAME));
+    }
+
+  /* Send an end of frame */
+
+  apa102_write32(priv, APA102_END_FRAME);
+
+  for (i = 0; i < (1 + APA102_XRES * APA102_YRES / 32); i++)
+    {
+      apa102_write32(priv, 0);
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getrun
+ *
+ * Description:
+ *   This method can be used to read a partial raster line from the LCD:
+ *
+ *  dev     - The lcd device
+ *  row     - Starting row to read from (range: 0 <= row < yres)
+ *  col     - Starting column to read read (range: 0 <= col <= xres-npixels)
+ *  buffer  - The buffer in which to return the run read from the LCD
+ *  npixels - The number of pixels to read from the LCD
+ *            (range: 0 < npixels <= xres-col)
+ *
+ ****************************************************************************/
+
+static int apa102_getrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                          fb_coord_t col, FAR uint8_t *buffer,
+                          size_t npixels)
+{
+  /* Because of this line of code, we will only be able to support a single
+   * APA102 device.
+   */
+
+  FAR struct apa102_dev_s *priv = (FAR struct apa102_dev_s *)dev;
+  int i;
+  int pixlen;
+
+  ginfo("row: %d col: %d npixels: %d\n", row, col, npixels);
+  DEBUGASSERT(buffer);
+
+  /* Clip the run to the display */
+
+  pixlen = npixels;
+  if ((unsigned int)col + (unsigned int)pixlen > (unsigned int)APA102_XRES)
+    {
+      pixlen = (int)APA102_XRES - (int)col;
+    }
+
+  /* Verify that some portion of the run is actually the display */
+
+  if (pixlen <= 0 || row > APA102_YRES)
+    {
+      return -EINVAL;
+    }
+
+  for (i = 0; i < pixlen; i++)
+    {
+      uint16_t *ptr = (uint16_t *) buffer;
+
+      *ptr++ = apa102_rgb565(priv->fb[(row * APA102_XRES) + col + i]);
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getvideoinfo
+ *
+ * Description:
+ *   Get information about the LCD video controller configuration.
+ *
+ ****************************************************************************/
+
+static int apa102_getvideoinfo(FAR struct lcd_dev_s *dev,
+                              FAR struct fb_videoinfo_s *vinfo)
+{
+  DEBUGASSERT(dev && vinfo);
+
+  ginfo("fmt: %d xres: %d yres: %d nplanes: %d\n",
+        g_videoinfo.fmt, g_videoinfo.xres, g_videoinfo.yres,
+        g_videoinfo.nplanes);
+
+  memcpy(vinfo, &g_videoinfo, sizeof(struct fb_videoinfo_s));
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getplaneinfo
+ *
+ * Description:
+ *   Get information about the configuration of each LCD color plane.
+ *
+ ****************************************************************************/
+
+static int apa102_getplaneinfo(FAR struct lcd_dev_s *dev,
+                                unsigned int planeno,
+                                FAR struct lcd_planeinfo_s *pinfo)

Review Comment:
   ```suggestion
   static int apa102_getplaneinfo(FAR struct lcd_dev_s *dev,
                                  unsigned int planeno,
                                  FAR struct lcd_planeinfo_s *pinfo)
   ```



##########
drivers/lcd/apa102.c:
##########
@@ -0,0 +1,667 @@
+/****************************************************************************
+ * drivers/lcd/apa102.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.
+ *
+ ****************************************************************************/
+
+/* Driver to create a display using RBG LEDs APA102 chained together */
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/spi/spi.h>
+#include <nuttx/lcd/lcd.h>
+#include <nuttx/lcd/apa102.h>
+#include <nuttx/leds/apa102.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define MAX(a,b)    ((a)>(b)?(a):(b))
+
+/* Configuration ************************************************************/
+
+/* APA102 Configuration Settings:
+ *
+ * CONFIG_APA102_XRES - Specifies the number of physical
+ *   APA102 devices that are connected together horizontally.
+ *
+ * CONFIG_APA102_YRES - Specifies the number of physical
+ *   APA102 devices that are connected together vertically.
+ *
+ * CONFIG_LCD_INTENSITY - Defines the default bright of LEDs.
+ *
+ * Required LCD driver settings:
+ * CONFIG_LCD_APA102 - Enable APA102 support
+ *
+ */
+
+/* Verify that all configuration requirements have been met */
+
+/* SPI frequency */
+
+#ifndef CONFIG_APA102_FREQUENCY
+#  define CONFIG_APA102_FREQUENCY 10000000
+#endif
+
+/* APA102_COLUMNS determines the number of physical LEDs
+ * matrices that are used connected horizontally.
+ */
+
+#ifndef CONFIG_APA102_XRES
+#  define CONFIG_APA102_XRES 16
+#endif
+
+/* APA102_LINES determines the number of physical LEDs
+ * matrices that are used connected vertically.
+ */
+
+#ifndef CONFIG_APA102_YRES
+#  define CONFIG_APA102_YRES 16
+#endif
+
+/* Check contrast selection */
+
+#if !defined(CONFIG_LCD_MAXCONTRAST)
+#  define CONFIG_LCD_MAXCONTRAST 1
+#endif
+
+/* Color Properties *********************************************************/
+
+/* Display Resolution */
+
+#define APA102_XRES         CONFIG_APA102_XRES
+#define APA102_YRES         CONFIG_APA102_YRES
+
+/* Color depth and format */
+
+#define APA102_BPP          16
+#define APA102_COLORFMT     FB_FMT_RGB16_565
+
+#define APA102_LUT_SIZE     MAX(APA102_XRES, APA102_YRES)
+
+/* The size of the shadow frame buffer (4 bytes per LED) */
+
+#define APA102_FBSIZE       (APA102_XRES * APA102_YRES)
+
+/* LCD RGB Mapping */
+
+#ifdef CONFIG_FB_CMAP
+#  error "RGB color mapping not supported by this driver"
+#endif
+
+/* Cursor Controls */
+
+#ifdef CONFIG_FB_HWCURSOR
+#  error "Cursor control not supported by this driver"
+#endif
+
+/****************************************************************************
+ * Private Type Definition
+ ****************************************************************************/
+
+/* This structure describes the state of this driver */
+
+struct apa102_dev_s
+{
+  /* Publicly visible device structure */
+
+  struct lcd_dev_s dev;
+
+  /* Private LCD-specific information follows */
+
+  FAR struct spi_dev_s *spi;
+  uint8_t contrast;
+  uint8_t powered;
+
+  /* We need to send all the APA102 matrix screen once.
+   * So, create a framebuffer to save it in memory
+   */
+
+  struct apa102_ledstrip_s fb[APA102_FBSIZE];
+};
+
+/****************************************************************************
+ * Private Function Protototypes
+ ****************************************************************************/
+
+/* LCD Data Transfer Methods */
+
+static int apa102_putrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR const uint8_t *buffer,
+                         size_t npixels);
+static int apa102_getrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR uint8_t *buffer,
+                         size_t npixels);
+
+/* LCD Configuration */
+
+static int apa102_getvideoinfo(FAR struct lcd_dev_s *dev,
+                               FAR struct fb_videoinfo_s *vinfo);
+static int apa102_getplaneinfo(FAR struct lcd_dev_s *dev,
+                               unsigned int planeno,
+                               FAR struct lcd_planeinfo_s *pinfo);
+
+/* LCD Specific Controls */
+
+static int apa102_getpower(FAR struct lcd_dev_s *dev);
+static int apa102_setpower(FAR struct lcd_dev_s *dev, int power);
+static int apa102_getcontrast(FAR struct lcd_dev_s *dev);
+static int apa102_setcontrast(FAR struct lcd_dev_s *dev,
+                               unsigned int contrast);
+
+/* Initialization */
+
+static inline void up_clear(FAR struct apa102_dev_s  *priv);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* This is working memory allocated by the LCD driver for each LCD device
+ * and for each color plane.  This memory will hold one raster line of data.
+ * The size of the allocated run buffer must therefore be at least
+ * (bpp * xres / 8).  Actual alignment of the buffer must conform to the
+ * bitwidth of the underlying pixel type.
+ *
+ * If there are multiple planes, they may share the same working buffer
+ * because different planes will not be operate on concurrently.  However,
+ * if there are multiple LCD devices, they must each have unique run buffers.
+ */
+
+static uint8_t g_runbuffer[APA102_LUT_SIZE];
+
+/* This structure describes the overall LCD video controller */
+
+static const struct fb_videoinfo_s g_videoinfo =
+{
+  APA102_COLORFMT,    /* Color format: RGB16-565: RRRR RGGG GGGB BBBB */
+  APA102_XRES,        /* Horizontal resolution in pixel columns */
+  APA102_YRES,        /* Vertical resolution in pixel rows */
+  1,                  /* Number of color planes supported */
+};
+
+/* This is the standard, NuttX Plane information object */
+
+static const struct lcd_planeinfo_s g_planeinfo =
+{
+  .putrun = apa102_putrun,              /* Put a run into LCD memory */
+  .getrun = apa102_getrun,              /* Get a run from LCD memory */
+  .buffer = (FAR uint8_t *)g_runbuffer, /* Run scratch buffer */
+  .bpp    = APA102_BPP,                 /* Bits-per-pixel */
+};
+
+/* This is the standard, NuttX LCD driver object */
+
+static struct apa102_dev_s g_apa102dev =
+{
+  /* struct lcd_dev_s */
+
+  {
+    /* LCD Configuration */
+
+    apa102_getvideoinfo,
+    apa102_getplaneinfo,
+
+#ifdef CONFIG_FB_CMAP
+    /* LCD RGB Mapping -- Not supported */
+
+    NULL,
+    NULL,
+#endif
+
+#ifdef CONFIG_FB_HWCURSOR
+    /* Cursor Controls -- Not supported */
+
+    NULL,
+    NULL,
+#endif
+
+    /* LCD Specific Controls */
+
+    apa102_getpower,
+    apa102_setpower,
+    apa102_getcontrast,
+    apa102_setcontrast,
+  },
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: rgb565_apa102
+ *
+ * Description:
+ *   Convert RGB565 to APA102 RGB888 format
+ *
+ ****************************************************************************/
+
+static struct apa102_ledstrip_s rgb565_apa102(uint16_t rgb565)
+{
+  struct apa102_ledstrip_s led;
+  led.red    = (rgb565 & 0b1111100000000000) >> 8;
+  led.green  = (rgb565 & 0b11111100000) >> 3;
+  led.blue   = (rgb565 & 0b11111) << 3;
+  led.bright = 0;
+  return led;
+}
+
+/****************************************************************************
+ * Name: apa102_rgb565
+ *
+ * Description:
+ *   Convert APA102 RGB888 to RGB565 format
+ *
+ ****************************************************************************/
+
+static uint16_t apa102_rgb565(struct apa102_ledstrip_s led)
+{
+  uint16_t pixel;
+
+  pixel  = (led.red & 0b11111000) << 8;
+  pixel |= (led.green & 0b11111100) << 3;
+  pixel |= (led.blue & 0b11111000) >> 3;
+  return pixel;
+}
+
+/****************************************************************************
+ * Name: apa102_configspi
+ *
+ * Description:
+ *   Set the SPI bus configuration
+ *
+ ****************************************************************************/
+
+static inline void apa102_configspi(FAR struct spi_dev_s *spi)
+{
+  /* Configure SPI for the APA102 */
+
+  SPI_SETMODE(spi, SPIDEV_MODE0);
+  SPI_SETBITS(spi, 8);
+  SPI_HWFEATURES(spi, 0);
+  SPI_SETFREQUENCY(spi, APA102_SPI_MAXFREQUENCY);
+}
+
+/****************************************************************************
+ * Name: apa102_write32
+ *
+ * Description:
+ *   Write 32-bit to APA102
+ *
+ ****************************************************************************/
+
+static inline void apa102_write32(FAR struct apa102_dev_s *priv,
+                                  FAR uint32_t value)
+{
+  /* If SPI bus is shared then lock and configure it */
+
+  SPI_LOCK(priv->spi, true);
+
+  /* Note: APA102 doesn't use chip select */
+
+  /* Send 32 bits (4 bytes) */
+
+  SPI_SEND(priv->spi, (value & 0xff));
+  SPI_SEND(priv->spi, ((value & 0xff00) >> 8));
+  SPI_SEND(priv->spi, ((value & 0xff0000) >> 16));
+  SPI_SEND(priv->spi, ((value & 0xff000000) >> 24));
+
+  /* Unlock bus */
+
+  SPI_LOCK(priv->spi, false);
+}
+
+/****************************************************************************
+ * Name:  apa102_putrun
+ *
+ * Description:
+ *   This method can be used to write a partial raster line to the LCD:
+ *
+ *   dev     - The lcd device
+ *   row     - Starting row to write to (range: 0 <= row < yres)
+ *   col     - Starting column to write to (range: 0 <= col <= xres-npixels)
+ *   buffer  - The buffer containing the run to be written to the LCD
+ *   npixels - The number of pixels to write to the LCD
+ *             (range: 0 < npixels <= xres-col)
+ *
+ ****************************************************************************/
+
+static int apa102_putrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                          fb_coord_t col, FAR const uint8_t *buffer,
+                          size_t npixels)
+{
+  /* Because of this line of code, we will only be able to support a single
+   * APA102 device .
+   */
+
+  FAR struct apa102_dev_s *priv = (FAR struct apa102_dev_s *)dev;
+  int i;
+  int pixlen;
+
+  ginfo("row: %d col: %d npixels: %d\n", row, col, npixels);
+  DEBUGASSERT(buffer && ((uintptr_t)buffer & 1) == 0);
+
+  /* Clip the run to the display */
+
+  pixlen = npixels;
+  if ((unsigned int)col + (unsigned int)pixlen > (unsigned int)APA102_XRES)
+    {
+      pixlen = (int)APA102_XRES - (int)col;
+    }
+
+  /* Verify that some portion of the run remains on the display */
+
+  if (pixlen <= 0 || row > APA102_YRES)
+    {
+      return OK;
+    }
+
+  /* Convert rgb565 to APA102 LED values */
+
+  for (i = 0; i < pixlen; i++)
+    {
+      uint16_t *ptr = (uint16_t *)buffer;
+
+      priv->fb[(row * APA102_XRES) + col + i] = rgb565_apa102(*ptr++);
+    }
+
+  /* Confirm that SPI is configured correctly */
+
+  apa102_configspi(priv->spi);
+
+  /* Send a start of frame */
+
+  apa102_write32(priv, APA102_START_FRAME);
+
+  /* Send all LEDs values in the matrix */
+
+  for (i = 0; i < (APA102_XRES * APA102_YRES); i++)
+    {
+      uint32_t *led = (uint32_t *) &priv->fb[i];
+
+      /* Then transfer 4 bytes per LED */
+
+      apa102_write32(priv, (uint32_t) (*led | APA102_HEADER_FRAME));
+    }
+
+  /* Send an end of frame */
+
+  apa102_write32(priv, APA102_END_FRAME);
+
+  for (i = 0; i < (1 + APA102_XRES * APA102_YRES / 32); i++)
+    {
+      apa102_write32(priv, 0);
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getrun
+ *
+ * Description:
+ *   This method can be used to read a partial raster line from the LCD:
+ *
+ *  dev     - The lcd device
+ *  row     - Starting row to read from (range: 0 <= row < yres)
+ *  col     - Starting column to read read (range: 0 <= col <= xres-npixels)
+ *  buffer  - The buffer in which to return the run read from the LCD
+ *  npixels - The number of pixels to read from the LCD
+ *            (range: 0 < npixels <= xres-col)
+ *
+ ****************************************************************************/
+
+static int apa102_getrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                          fb_coord_t col, FAR uint8_t *buffer,
+                          size_t npixels)

Review Comment:
   ```suggestion
   static int apa102_getrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
                            fb_coord_t col, FAR uint8_t *buffer,
                            size_t npixels)
   ```



##########
drivers/lcd/apa102.c:
##########
@@ -0,0 +1,667 @@
+/****************************************************************************
+ * drivers/lcd/apa102.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.
+ *
+ ****************************************************************************/
+
+/* Driver to create a display using RBG LEDs APA102 chained together */
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/spi/spi.h>
+#include <nuttx/lcd/lcd.h>
+#include <nuttx/lcd/apa102.h>
+#include <nuttx/leds/apa102.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define MAX(a,b)    ((a)>(b)?(a):(b))
+
+/* Configuration ************************************************************/
+
+/* APA102 Configuration Settings:
+ *
+ * CONFIG_APA102_XRES - Specifies the number of physical
+ *   APA102 devices that are connected together horizontally.
+ *
+ * CONFIG_APA102_YRES - Specifies the number of physical
+ *   APA102 devices that are connected together vertically.
+ *
+ * CONFIG_LCD_INTENSITY - Defines the default bright of LEDs.
+ *
+ * Required LCD driver settings:
+ * CONFIG_LCD_APA102 - Enable APA102 support
+ *
+ */
+
+/* Verify that all configuration requirements have been met */
+
+/* SPI frequency */
+
+#ifndef CONFIG_APA102_FREQUENCY
+#  define CONFIG_APA102_FREQUENCY 10000000
+#endif
+
+/* APA102_COLUMNS determines the number of physical LEDs
+ * matrices that are used connected horizontally.
+ */
+
+#ifndef CONFIG_APA102_XRES
+#  define CONFIG_APA102_XRES 16
+#endif
+
+/* APA102_LINES determines the number of physical LEDs
+ * matrices that are used connected vertically.
+ */
+
+#ifndef CONFIG_APA102_YRES
+#  define CONFIG_APA102_YRES 16
+#endif
+
+/* Check contrast selection */
+
+#if !defined(CONFIG_LCD_MAXCONTRAST)
+#  define CONFIG_LCD_MAXCONTRAST 1
+#endif
+
+/* Color Properties *********************************************************/
+
+/* Display Resolution */
+
+#define APA102_XRES         CONFIG_APA102_XRES
+#define APA102_YRES         CONFIG_APA102_YRES
+
+/* Color depth and format */
+
+#define APA102_BPP          16
+#define APA102_COLORFMT     FB_FMT_RGB16_565
+
+#define APA102_LUT_SIZE     MAX(APA102_XRES, APA102_YRES)
+
+/* The size of the shadow frame buffer (4 bytes per LED) */
+
+#define APA102_FBSIZE       (APA102_XRES * APA102_YRES)
+
+/* LCD RGB Mapping */
+
+#ifdef CONFIG_FB_CMAP
+#  error "RGB color mapping not supported by this driver"
+#endif
+
+/* Cursor Controls */
+
+#ifdef CONFIG_FB_HWCURSOR
+#  error "Cursor control not supported by this driver"
+#endif
+
+/****************************************************************************
+ * Private Type Definition
+ ****************************************************************************/
+
+/* This structure describes the state of this driver */
+
+struct apa102_dev_s
+{
+  /* Publicly visible device structure */
+
+  struct lcd_dev_s dev;
+
+  /* Private LCD-specific information follows */
+
+  FAR struct spi_dev_s *spi;
+  uint8_t contrast;
+  uint8_t powered;
+
+  /* We need to send all the APA102 matrix screen once.
+   * So, create a framebuffer to save it in memory
+   */
+
+  struct apa102_ledstrip_s fb[APA102_FBSIZE];
+};
+
+/****************************************************************************
+ * Private Function Protototypes
+ ****************************************************************************/
+
+/* LCD Data Transfer Methods */
+
+static int apa102_putrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR const uint8_t *buffer,
+                         size_t npixels);
+static int apa102_getrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR uint8_t *buffer,
+                         size_t npixels);
+
+/* LCD Configuration */
+
+static int apa102_getvideoinfo(FAR struct lcd_dev_s *dev,
+                               FAR struct fb_videoinfo_s *vinfo);
+static int apa102_getplaneinfo(FAR struct lcd_dev_s *dev,
+                               unsigned int planeno,
+                               FAR struct lcd_planeinfo_s *pinfo);
+
+/* LCD Specific Controls */
+
+static int apa102_getpower(FAR struct lcd_dev_s *dev);
+static int apa102_setpower(FAR struct lcd_dev_s *dev, int power);
+static int apa102_getcontrast(FAR struct lcd_dev_s *dev);
+static int apa102_setcontrast(FAR struct lcd_dev_s *dev,
+                               unsigned int contrast);
+
+/* Initialization */
+
+static inline void up_clear(FAR struct apa102_dev_s  *priv);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* This is working memory allocated by the LCD driver for each LCD device
+ * and for each color plane.  This memory will hold one raster line of data.
+ * The size of the allocated run buffer must therefore be at least
+ * (bpp * xres / 8).  Actual alignment of the buffer must conform to the
+ * bitwidth of the underlying pixel type.
+ *
+ * If there are multiple planes, they may share the same working buffer
+ * because different planes will not be operate on concurrently.  However,
+ * if there are multiple LCD devices, they must each have unique run buffers.
+ */
+
+static uint8_t g_runbuffer[APA102_LUT_SIZE];
+
+/* This structure describes the overall LCD video controller */
+
+static const struct fb_videoinfo_s g_videoinfo =
+{
+  APA102_COLORFMT,    /* Color format: RGB16-565: RRRR RGGG GGGB BBBB */
+  APA102_XRES,        /* Horizontal resolution in pixel columns */
+  APA102_YRES,        /* Vertical resolution in pixel rows */
+  1,                  /* Number of color planes supported */
+};
+
+/* This is the standard, NuttX Plane information object */
+
+static const struct lcd_planeinfo_s g_planeinfo =
+{
+  .putrun = apa102_putrun,              /* Put a run into LCD memory */
+  .getrun = apa102_getrun,              /* Get a run from LCD memory */
+  .buffer = (FAR uint8_t *)g_runbuffer, /* Run scratch buffer */
+  .bpp    = APA102_BPP,                 /* Bits-per-pixel */
+};
+
+/* This is the standard, NuttX LCD driver object */
+
+static struct apa102_dev_s g_apa102dev =
+{
+  /* struct lcd_dev_s */
+
+  {
+    /* LCD Configuration */
+
+    apa102_getvideoinfo,
+    apa102_getplaneinfo,
+
+#ifdef CONFIG_FB_CMAP
+    /* LCD RGB Mapping -- Not supported */
+
+    NULL,
+    NULL,
+#endif
+
+#ifdef CONFIG_FB_HWCURSOR
+    /* Cursor Controls -- Not supported */
+
+    NULL,
+    NULL,
+#endif
+
+    /* LCD Specific Controls */
+
+    apa102_getpower,
+    apa102_setpower,
+    apa102_getcontrast,
+    apa102_setcontrast,
+  },
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: rgb565_apa102
+ *
+ * Description:
+ *   Convert RGB565 to APA102 RGB888 format
+ *
+ ****************************************************************************/
+
+static struct apa102_ledstrip_s rgb565_apa102(uint16_t rgb565)
+{
+  struct apa102_ledstrip_s led;
+  led.red    = (rgb565 & 0b1111100000000000) >> 8;
+  led.green  = (rgb565 & 0b11111100000) >> 3;
+  led.blue   = (rgb565 & 0b11111) << 3;
+  led.bright = 0;
+  return led;
+}
+
+/****************************************************************************
+ * Name: apa102_rgb565
+ *
+ * Description:
+ *   Convert APA102 RGB888 to RGB565 format
+ *
+ ****************************************************************************/
+
+static uint16_t apa102_rgb565(struct apa102_ledstrip_s led)
+{
+  uint16_t pixel;
+
+  pixel  = (led.red & 0b11111000) << 8;
+  pixel |= (led.green & 0b11111100) << 3;
+  pixel |= (led.blue & 0b11111000) >> 3;
+  return pixel;
+}
+
+/****************************************************************************
+ * Name: apa102_configspi
+ *
+ * Description:
+ *   Set the SPI bus configuration
+ *
+ ****************************************************************************/
+
+static inline void apa102_configspi(FAR struct spi_dev_s *spi)
+{
+  /* Configure SPI for the APA102 */
+
+  SPI_SETMODE(spi, SPIDEV_MODE0);
+  SPI_SETBITS(spi, 8);
+  SPI_HWFEATURES(spi, 0);
+  SPI_SETFREQUENCY(spi, APA102_SPI_MAXFREQUENCY);
+}
+
+/****************************************************************************
+ * Name: apa102_write32
+ *
+ * Description:
+ *   Write 32-bit to APA102
+ *
+ ****************************************************************************/
+
+static inline void apa102_write32(FAR struct apa102_dev_s *priv,
+                                  FAR uint32_t value)
+{
+  /* If SPI bus is shared then lock and configure it */
+
+  SPI_LOCK(priv->spi, true);
+
+  /* Note: APA102 doesn't use chip select */
+
+  /* Send 32 bits (4 bytes) */
+
+  SPI_SEND(priv->spi, (value & 0xff));
+  SPI_SEND(priv->spi, ((value & 0xff00) >> 8));
+  SPI_SEND(priv->spi, ((value & 0xff0000) >> 16));
+  SPI_SEND(priv->spi, ((value & 0xff000000) >> 24));
+
+  /* Unlock bus */
+
+  SPI_LOCK(priv->spi, false);
+}
+
+/****************************************************************************
+ * Name:  apa102_putrun
+ *
+ * Description:
+ *   This method can be used to write a partial raster line to the LCD:
+ *
+ *   dev     - The lcd device
+ *   row     - Starting row to write to (range: 0 <= row < yres)
+ *   col     - Starting column to write to (range: 0 <= col <= xres-npixels)
+ *   buffer  - The buffer containing the run to be written to the LCD
+ *   npixels - The number of pixels to write to the LCD
+ *             (range: 0 < npixels <= xres-col)
+ *
+ ****************************************************************************/
+
+static int apa102_putrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                          fb_coord_t col, FAR const uint8_t *buffer,
+                          size_t npixels)
+{
+  /* Because of this line of code, we will only be able to support a single
+   * APA102 device .
+   */
+
+  FAR struct apa102_dev_s *priv = (FAR struct apa102_dev_s *)dev;
+  int i;
+  int pixlen;
+
+  ginfo("row: %d col: %d npixels: %d\n", row, col, npixels);
+  DEBUGASSERT(buffer && ((uintptr_t)buffer & 1) == 0);
+
+  /* Clip the run to the display */
+
+  pixlen = npixels;
+  if ((unsigned int)col + (unsigned int)pixlen > (unsigned int)APA102_XRES)
+    {
+      pixlen = (int)APA102_XRES - (int)col;
+    }
+
+  /* Verify that some portion of the run remains on the display */
+
+  if (pixlen <= 0 || row > APA102_YRES)
+    {
+      return OK;
+    }
+
+  /* Convert rgb565 to APA102 LED values */
+
+  for (i = 0; i < pixlen; i++)
+    {
+      uint16_t *ptr = (uint16_t *)buffer;
+
+      priv->fb[(row * APA102_XRES) + col + i] = rgb565_apa102(*ptr++);
+    }
+
+  /* Confirm that SPI is configured correctly */
+
+  apa102_configspi(priv->spi);
+
+  /* Send a start of frame */
+
+  apa102_write32(priv, APA102_START_FRAME);
+
+  /* Send all LEDs values in the matrix */
+
+  for (i = 0; i < (APA102_XRES * APA102_YRES); i++)
+    {
+      uint32_t *led = (uint32_t *) &priv->fb[i];
+
+      /* Then transfer 4 bytes per LED */
+
+      apa102_write32(priv, (uint32_t) (*led | APA102_HEADER_FRAME));
+    }
+
+  /* Send an end of frame */
+
+  apa102_write32(priv, APA102_END_FRAME);
+
+  for (i = 0; i < (1 + APA102_XRES * APA102_YRES / 32); i++)
+    {
+      apa102_write32(priv, 0);
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getrun
+ *
+ * Description:
+ *   This method can be used to read a partial raster line from the LCD:
+ *
+ *  dev     - The lcd device
+ *  row     - Starting row to read from (range: 0 <= row < yres)
+ *  col     - Starting column to read read (range: 0 <= col <= xres-npixels)
+ *  buffer  - The buffer in which to return the run read from the LCD
+ *  npixels - The number of pixels to read from the LCD
+ *            (range: 0 < npixels <= xres-col)
+ *
+ ****************************************************************************/
+
+static int apa102_getrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                          fb_coord_t col, FAR uint8_t *buffer,
+                          size_t npixels)
+{
+  /* Because of this line of code, we will only be able to support a single
+   * APA102 device.
+   */
+
+  FAR struct apa102_dev_s *priv = (FAR struct apa102_dev_s *)dev;
+  int i;
+  int pixlen;
+
+  ginfo("row: %d col: %d npixels: %d\n", row, col, npixels);
+  DEBUGASSERT(buffer);
+
+  /* Clip the run to the display */
+
+  pixlen = npixels;
+  if ((unsigned int)col + (unsigned int)pixlen > (unsigned int)APA102_XRES)
+    {
+      pixlen = (int)APA102_XRES - (int)col;
+    }
+
+  /* Verify that some portion of the run is actually the display */
+
+  if (pixlen <= 0 || row > APA102_YRES)
+    {
+      return -EINVAL;
+    }
+
+  for (i = 0; i < pixlen; i++)
+    {
+      uint16_t *ptr = (uint16_t *) buffer;
+
+      *ptr++ = apa102_rgb565(priv->fb[(row * APA102_XRES) + col + i]);
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getvideoinfo
+ *
+ * Description:
+ *   Get information about the LCD video controller configuration.
+ *
+ ****************************************************************************/
+
+static int apa102_getvideoinfo(FAR struct lcd_dev_s *dev,
+                              FAR struct fb_videoinfo_s *vinfo)
+{
+  DEBUGASSERT(dev && vinfo);
+
+  ginfo("fmt: %d xres: %d yres: %d nplanes: %d\n",
+        g_videoinfo.fmt, g_videoinfo.xres, g_videoinfo.yres,
+        g_videoinfo.nplanes);
+
+  memcpy(vinfo, &g_videoinfo, sizeof(struct fb_videoinfo_s));
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getplaneinfo
+ *
+ * Description:
+ *   Get information about the configuration of each LCD color plane.
+ *
+ ****************************************************************************/
+
+static int apa102_getplaneinfo(FAR struct lcd_dev_s *dev,
+                                unsigned int planeno,
+                                FAR struct lcd_planeinfo_s *pinfo)
+{
+  DEBUGASSERT(dev && pinfo && planeno == 0);
+
+  ginfo("planeno: %d bpp: %d\n", planeno, g_planeinfo.bpp);
+
+  memcpy(pinfo, &g_planeinfo, sizeof(struct lcd_planeinfo_s));
+  pinfo->dev = dev;
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getpower
+ *
+ * Description:
+ *   Get the LCD panel power status (0: full off - CONFIG_LCD_MAXPOWER: full
+ *   on). On backlit LCDs, this setting may correspond to the backlight
+ *   setting.
+ *
+ ****************************************************************************/
+
+static int apa102_getpower(struct lcd_dev_s *dev)
+{
+  struct apa102_dev_s *priv = (struct apa102_dev_s *)dev;
+
+  DEBUGASSERT(priv);
+  ginfo("powered: %d\n", priv->powered);
+
+  return priv->powered;
+}
+
+/****************************************************************************
+ * Name:  apa102_setpower
+ *
+ * Description:
+ *   Enable/disable LCD panel power (0: full off - CONFIG_LCD_MAXPOWER: full
+ *   on). On backlit LCDs, this setting may correspond to the backlight
+ *   setting.
+ *
+ ****************************************************************************/
+
+static int apa102_setpower(struct lcd_dev_s *dev, int power)
+{
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getcontrast
+ *
+ * Description:
+ *   Get the current contrast setting (0-CONFIG_LCD_MAXCONTRAST).
+ *
+ ****************************************************************************/
+
+static int apa102_getcontrast(struct lcd_dev_s *dev)
+{
+  struct apa102_dev_s *priv = (struct apa102_dev_s *)dev;

Review Comment:
   ```suggestion
   static int apa102_getcontrast(FAR struct lcd_dev_s *dev)
   {
     struct apa102_dev_s *priv = (FAR struct apa102_dev_s *)dev;
   ```



##########
drivers/lcd/apa102.c:
##########
@@ -0,0 +1,667 @@
+/****************************************************************************
+ * drivers/lcd/apa102.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.
+ *
+ ****************************************************************************/
+
+/* Driver to create a display using RBG LEDs APA102 chained together */
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/spi/spi.h>
+#include <nuttx/lcd/lcd.h>
+#include <nuttx/lcd/apa102.h>
+#include <nuttx/leds/apa102.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define MAX(a,b)    ((a)>(b)?(a):(b))
+
+/* Configuration ************************************************************/
+
+/* APA102 Configuration Settings:
+ *
+ * CONFIG_APA102_XRES - Specifies the number of physical
+ *   APA102 devices that are connected together horizontally.
+ *
+ * CONFIG_APA102_YRES - Specifies the number of physical
+ *   APA102 devices that are connected together vertically.
+ *
+ * CONFIG_LCD_INTENSITY - Defines the default bright of LEDs.
+ *
+ * Required LCD driver settings:
+ * CONFIG_LCD_APA102 - Enable APA102 support
+ *
+ */
+
+/* Verify that all configuration requirements have been met */
+
+/* SPI frequency */
+
+#ifndef CONFIG_APA102_FREQUENCY
+#  define CONFIG_APA102_FREQUENCY 10000000
+#endif
+
+/* APA102_COLUMNS determines the number of physical LEDs
+ * matrices that are used connected horizontally.
+ */
+
+#ifndef CONFIG_APA102_XRES
+#  define CONFIG_APA102_XRES 16
+#endif
+
+/* APA102_LINES determines the number of physical LEDs
+ * matrices that are used connected vertically.
+ */
+
+#ifndef CONFIG_APA102_YRES
+#  define CONFIG_APA102_YRES 16
+#endif
+
+/* Check contrast selection */
+
+#if !defined(CONFIG_LCD_MAXCONTRAST)
+#  define CONFIG_LCD_MAXCONTRAST 1
+#endif
+
+/* Color Properties *********************************************************/
+
+/* Display Resolution */
+
+#define APA102_XRES         CONFIG_APA102_XRES
+#define APA102_YRES         CONFIG_APA102_YRES
+
+/* Color depth and format */
+
+#define APA102_BPP          16
+#define APA102_COLORFMT     FB_FMT_RGB16_565
+
+#define APA102_LUT_SIZE     MAX(APA102_XRES, APA102_YRES)
+
+/* The size of the shadow frame buffer (4 bytes per LED) */
+
+#define APA102_FBSIZE       (APA102_XRES * APA102_YRES)
+
+/* LCD RGB Mapping */
+
+#ifdef CONFIG_FB_CMAP
+#  error "RGB color mapping not supported by this driver"
+#endif
+
+/* Cursor Controls */
+
+#ifdef CONFIG_FB_HWCURSOR
+#  error "Cursor control not supported by this driver"
+#endif
+
+/****************************************************************************
+ * Private Type Definition
+ ****************************************************************************/
+
+/* This structure describes the state of this driver */
+
+struct apa102_dev_s
+{
+  /* Publicly visible device structure */
+
+  struct lcd_dev_s dev;
+
+  /* Private LCD-specific information follows */
+
+  FAR struct spi_dev_s *spi;
+  uint8_t contrast;
+  uint8_t powered;
+
+  /* We need to send all the APA102 matrix screen once.
+   * So, create a framebuffer to save it in memory
+   */
+
+  struct apa102_ledstrip_s fb[APA102_FBSIZE];
+};
+
+/****************************************************************************
+ * Private Function Protototypes
+ ****************************************************************************/
+
+/* LCD Data Transfer Methods */
+
+static int apa102_putrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR const uint8_t *buffer,
+                         size_t npixels);
+static int apa102_getrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR uint8_t *buffer,
+                         size_t npixels);
+
+/* LCD Configuration */
+
+static int apa102_getvideoinfo(FAR struct lcd_dev_s *dev,
+                               FAR struct fb_videoinfo_s *vinfo);
+static int apa102_getplaneinfo(FAR struct lcd_dev_s *dev,
+                               unsigned int planeno,
+                               FAR struct lcd_planeinfo_s *pinfo);
+
+/* LCD Specific Controls */
+
+static int apa102_getpower(FAR struct lcd_dev_s *dev);
+static int apa102_setpower(FAR struct lcd_dev_s *dev, int power);
+static int apa102_getcontrast(FAR struct lcd_dev_s *dev);
+static int apa102_setcontrast(FAR struct lcd_dev_s *dev,
+                               unsigned int contrast);
+
+/* Initialization */
+
+static inline void up_clear(FAR struct apa102_dev_s  *priv);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* This is working memory allocated by the LCD driver for each LCD device
+ * and for each color plane.  This memory will hold one raster line of data.
+ * The size of the allocated run buffer must therefore be at least
+ * (bpp * xres / 8).  Actual alignment of the buffer must conform to the
+ * bitwidth of the underlying pixel type.
+ *
+ * If there are multiple planes, they may share the same working buffer
+ * because different planes will not be operate on concurrently.  However,
+ * if there are multiple LCD devices, they must each have unique run buffers.
+ */
+
+static uint8_t g_runbuffer[APA102_LUT_SIZE];
+
+/* This structure describes the overall LCD video controller */
+
+static const struct fb_videoinfo_s g_videoinfo =
+{
+  APA102_COLORFMT,    /* Color format: RGB16-565: RRRR RGGG GGGB BBBB */
+  APA102_XRES,        /* Horizontal resolution in pixel columns */
+  APA102_YRES,        /* Vertical resolution in pixel rows */
+  1,                  /* Number of color planes supported */
+};
+
+/* This is the standard, NuttX Plane information object */
+
+static const struct lcd_planeinfo_s g_planeinfo =
+{
+  .putrun = apa102_putrun,              /* Put a run into LCD memory */
+  .getrun = apa102_getrun,              /* Get a run from LCD memory */
+  .buffer = (FAR uint8_t *)g_runbuffer, /* Run scratch buffer */
+  .bpp    = APA102_BPP,                 /* Bits-per-pixel */
+};
+
+/* This is the standard, NuttX LCD driver object */
+
+static struct apa102_dev_s g_apa102dev =
+{
+  /* struct lcd_dev_s */
+
+  {
+    /* LCD Configuration */
+
+    apa102_getvideoinfo,
+    apa102_getplaneinfo,
+
+#ifdef CONFIG_FB_CMAP
+    /* LCD RGB Mapping -- Not supported */
+
+    NULL,
+    NULL,
+#endif
+
+#ifdef CONFIG_FB_HWCURSOR
+    /* Cursor Controls -- Not supported */
+
+    NULL,
+    NULL,
+#endif
+
+    /* LCD Specific Controls */
+
+    apa102_getpower,
+    apa102_setpower,
+    apa102_getcontrast,
+    apa102_setcontrast,
+  },
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: rgb565_apa102
+ *
+ * Description:
+ *   Convert RGB565 to APA102 RGB888 format
+ *
+ ****************************************************************************/
+
+static struct apa102_ledstrip_s rgb565_apa102(uint16_t rgb565)
+{
+  struct apa102_ledstrip_s led;
+  led.red    = (rgb565 & 0b1111100000000000) >> 8;
+  led.green  = (rgb565 & 0b11111100000) >> 3;
+  led.blue   = (rgb565 & 0b11111) << 3;
+  led.bright = 0;
+  return led;
+}
+
+/****************************************************************************
+ * Name: apa102_rgb565
+ *
+ * Description:
+ *   Convert APA102 RGB888 to RGB565 format
+ *
+ ****************************************************************************/
+
+static uint16_t apa102_rgb565(struct apa102_ledstrip_s led)
+{
+  uint16_t pixel;
+
+  pixel  = (led.red & 0b11111000) << 8;
+  pixel |= (led.green & 0b11111100) << 3;
+  pixel |= (led.blue & 0b11111000) >> 3;
+  return pixel;
+}
+
+/****************************************************************************
+ * Name: apa102_configspi
+ *
+ * Description:
+ *   Set the SPI bus configuration
+ *
+ ****************************************************************************/
+
+static inline void apa102_configspi(FAR struct spi_dev_s *spi)
+{
+  /* Configure SPI for the APA102 */
+
+  SPI_SETMODE(spi, SPIDEV_MODE0);
+  SPI_SETBITS(spi, 8);
+  SPI_HWFEATURES(spi, 0);
+  SPI_SETFREQUENCY(spi, APA102_SPI_MAXFREQUENCY);
+}
+
+/****************************************************************************
+ * Name: apa102_write32
+ *
+ * Description:
+ *   Write 32-bit to APA102
+ *
+ ****************************************************************************/
+
+static inline void apa102_write32(FAR struct apa102_dev_s *priv,
+                                  FAR uint32_t value)
+{
+  /* If SPI bus is shared then lock and configure it */
+
+  SPI_LOCK(priv->spi, true);
+
+  /* Note: APA102 doesn't use chip select */
+
+  /* Send 32 bits (4 bytes) */
+
+  SPI_SEND(priv->spi, (value & 0xff));
+  SPI_SEND(priv->spi, ((value & 0xff00) >> 8));
+  SPI_SEND(priv->spi, ((value & 0xff0000) >> 16));
+  SPI_SEND(priv->spi, ((value & 0xff000000) >> 24));
+
+  /* Unlock bus */
+
+  SPI_LOCK(priv->spi, false);
+}
+
+/****************************************************************************
+ * Name:  apa102_putrun
+ *
+ * Description:
+ *   This method can be used to write a partial raster line to the LCD:
+ *
+ *   dev     - The lcd device
+ *   row     - Starting row to write to (range: 0 <= row < yres)
+ *   col     - Starting column to write to (range: 0 <= col <= xres-npixels)
+ *   buffer  - The buffer containing the run to be written to the LCD
+ *   npixels - The number of pixels to write to the LCD
+ *             (range: 0 < npixels <= xres-col)
+ *
+ ****************************************************************************/
+
+static int apa102_putrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                          fb_coord_t col, FAR const uint8_t *buffer,
+                          size_t npixels)
+{
+  /* Because of this line of code, we will only be able to support a single
+   * APA102 device .
+   */
+
+  FAR struct apa102_dev_s *priv = (FAR struct apa102_dev_s *)dev;
+  int i;
+  int pixlen;
+
+  ginfo("row: %d col: %d npixels: %d\n", row, col, npixels);
+  DEBUGASSERT(buffer && ((uintptr_t)buffer & 1) == 0);
+
+  /* Clip the run to the display */
+
+  pixlen = npixels;
+  if ((unsigned int)col + (unsigned int)pixlen > (unsigned int)APA102_XRES)
+    {
+      pixlen = (int)APA102_XRES - (int)col;
+    }
+
+  /* Verify that some portion of the run remains on the display */
+
+  if (pixlen <= 0 || row > APA102_YRES)
+    {
+      return OK;
+    }
+
+  /* Convert rgb565 to APA102 LED values */
+
+  for (i = 0; i < pixlen; i++)
+    {
+      uint16_t *ptr = (uint16_t *)buffer;
+
+      priv->fb[(row * APA102_XRES) + col + i] = rgb565_apa102(*ptr++);
+    }
+
+  /* Confirm that SPI is configured correctly */
+
+  apa102_configspi(priv->spi);
+
+  /* Send a start of frame */
+
+  apa102_write32(priv, APA102_START_FRAME);
+
+  /* Send all LEDs values in the matrix */
+
+  for (i = 0; i < (APA102_XRES * APA102_YRES); i++)
+    {
+      uint32_t *led = (uint32_t *) &priv->fb[i];
+
+      /* Then transfer 4 bytes per LED */
+
+      apa102_write32(priv, (uint32_t) (*led | APA102_HEADER_FRAME));
+    }
+
+  /* Send an end of frame */
+
+  apa102_write32(priv, APA102_END_FRAME);
+
+  for (i = 0; i < (1 + APA102_XRES * APA102_YRES / 32); i++)
+    {
+      apa102_write32(priv, 0);
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getrun
+ *
+ * Description:
+ *   This method can be used to read a partial raster line from the LCD:
+ *
+ *  dev     - The lcd device
+ *  row     - Starting row to read from (range: 0 <= row < yres)
+ *  col     - Starting column to read read (range: 0 <= col <= xres-npixels)
+ *  buffer  - The buffer in which to return the run read from the LCD
+ *  npixels - The number of pixels to read from the LCD
+ *            (range: 0 < npixels <= xres-col)
+ *
+ ****************************************************************************/
+
+static int apa102_getrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                          fb_coord_t col, FAR uint8_t *buffer,
+                          size_t npixels)
+{
+  /* Because of this line of code, we will only be able to support a single
+   * APA102 device.
+   */
+
+  FAR struct apa102_dev_s *priv = (FAR struct apa102_dev_s *)dev;
+  int i;
+  int pixlen;
+
+  ginfo("row: %d col: %d npixels: %d\n", row, col, npixels);
+  DEBUGASSERT(buffer);
+
+  /* Clip the run to the display */
+
+  pixlen = npixels;
+  if ((unsigned int)col + (unsigned int)pixlen > (unsigned int)APA102_XRES)
+    {
+      pixlen = (int)APA102_XRES - (int)col;
+    }
+
+  /* Verify that some portion of the run is actually the display */
+
+  if (pixlen <= 0 || row > APA102_YRES)
+    {
+      return -EINVAL;
+    }
+
+  for (i = 0; i < pixlen; i++)
+    {
+      uint16_t *ptr = (uint16_t *) buffer;
+
+      *ptr++ = apa102_rgb565(priv->fb[(row * APA102_XRES) + col + i]);
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getvideoinfo
+ *
+ * Description:
+ *   Get information about the LCD video controller configuration.
+ *
+ ****************************************************************************/
+
+static int apa102_getvideoinfo(FAR struct lcd_dev_s *dev,
+                              FAR struct fb_videoinfo_s *vinfo)
+{
+  DEBUGASSERT(dev && vinfo);
+
+  ginfo("fmt: %d xres: %d yres: %d nplanes: %d\n",
+        g_videoinfo.fmt, g_videoinfo.xres, g_videoinfo.yres,
+        g_videoinfo.nplanes);
+
+  memcpy(vinfo, &g_videoinfo, sizeof(struct fb_videoinfo_s));
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getplaneinfo
+ *
+ * Description:
+ *   Get information about the configuration of each LCD color plane.
+ *
+ ****************************************************************************/
+
+static int apa102_getplaneinfo(FAR struct lcd_dev_s *dev,
+                                unsigned int planeno,
+                                FAR struct lcd_planeinfo_s *pinfo)
+{
+  DEBUGASSERT(dev && pinfo && planeno == 0);
+
+  ginfo("planeno: %d bpp: %d\n", planeno, g_planeinfo.bpp);
+
+  memcpy(pinfo, &g_planeinfo, sizeof(struct lcd_planeinfo_s));
+  pinfo->dev = dev;
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getpower
+ *
+ * Description:
+ *   Get the LCD panel power status (0: full off - CONFIG_LCD_MAXPOWER: full
+ *   on). On backlit LCDs, this setting may correspond to the backlight
+ *   setting.
+ *
+ ****************************************************************************/
+
+static int apa102_getpower(struct lcd_dev_s *dev)
+{
+  struct apa102_dev_s *priv = (struct apa102_dev_s *)dev;

Review Comment:
   ```suggestion
   static int apa102_getpower(FAR struct lcd_dev_s *dev)
   {
     struct apa102_dev_s *priv = (FAR struct apa102_dev_s *)dev;
   ```



##########
drivers/lcd/apa102.c:
##########
@@ -0,0 +1,667 @@
+/****************************************************************************
+ * drivers/lcd/apa102.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.
+ *
+ ****************************************************************************/
+
+/* Driver to create a display using RBG LEDs APA102 chained together */
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/spi/spi.h>
+#include <nuttx/lcd/lcd.h>
+#include <nuttx/lcd/apa102.h>
+#include <nuttx/leds/apa102.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define MAX(a,b)    ((a)>(b)?(a):(b))
+
+/* Configuration ************************************************************/
+
+/* APA102 Configuration Settings:
+ *
+ * CONFIG_APA102_XRES - Specifies the number of physical
+ *   APA102 devices that are connected together horizontally.
+ *
+ * CONFIG_APA102_YRES - Specifies the number of physical
+ *   APA102 devices that are connected together vertically.
+ *
+ * CONFIG_LCD_INTENSITY - Defines the default bright of LEDs.
+ *
+ * Required LCD driver settings:
+ * CONFIG_LCD_APA102 - Enable APA102 support
+ *
+ */
+
+/* Verify that all configuration requirements have been met */
+
+/* SPI frequency */
+
+#ifndef CONFIG_APA102_FREQUENCY
+#  define CONFIG_APA102_FREQUENCY 10000000
+#endif
+
+/* APA102_COLUMNS determines the number of physical LEDs
+ * matrices that are used connected horizontally.
+ */
+
+#ifndef CONFIG_APA102_XRES
+#  define CONFIG_APA102_XRES 16
+#endif
+
+/* APA102_LINES determines the number of physical LEDs
+ * matrices that are used connected vertically.
+ */
+
+#ifndef CONFIG_APA102_YRES
+#  define CONFIG_APA102_YRES 16
+#endif
+
+/* Check contrast selection */
+
+#if !defined(CONFIG_LCD_MAXCONTRAST)
+#  define CONFIG_LCD_MAXCONTRAST 1
+#endif
+
+/* Color Properties *********************************************************/
+
+/* Display Resolution */
+
+#define APA102_XRES         CONFIG_APA102_XRES
+#define APA102_YRES         CONFIG_APA102_YRES
+
+/* Color depth and format */
+
+#define APA102_BPP          16
+#define APA102_COLORFMT     FB_FMT_RGB16_565
+
+#define APA102_LUT_SIZE     MAX(APA102_XRES, APA102_YRES)
+
+/* The size of the shadow frame buffer (4 bytes per LED) */
+
+#define APA102_FBSIZE       (APA102_XRES * APA102_YRES)
+
+/* LCD RGB Mapping */
+
+#ifdef CONFIG_FB_CMAP
+#  error "RGB color mapping not supported by this driver"
+#endif
+
+/* Cursor Controls */
+
+#ifdef CONFIG_FB_HWCURSOR
+#  error "Cursor control not supported by this driver"
+#endif
+
+/****************************************************************************
+ * Private Type Definition
+ ****************************************************************************/
+
+/* This structure describes the state of this driver */
+
+struct apa102_dev_s
+{
+  /* Publicly visible device structure */
+
+  struct lcd_dev_s dev;
+
+  /* Private LCD-specific information follows */
+
+  FAR struct spi_dev_s *spi;
+  uint8_t contrast;
+  uint8_t powered;
+
+  /* We need to send all the APA102 matrix screen once.
+   * So, create a framebuffer to save it in memory
+   */
+
+  struct apa102_ledstrip_s fb[APA102_FBSIZE];
+};
+
+/****************************************************************************
+ * Private Function Protototypes
+ ****************************************************************************/
+
+/* LCD Data Transfer Methods */
+
+static int apa102_putrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR const uint8_t *buffer,
+                         size_t npixels);
+static int apa102_getrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                         fb_coord_t col, FAR uint8_t *buffer,
+                         size_t npixels);
+
+/* LCD Configuration */
+
+static int apa102_getvideoinfo(FAR struct lcd_dev_s *dev,
+                               FAR struct fb_videoinfo_s *vinfo);
+static int apa102_getplaneinfo(FAR struct lcd_dev_s *dev,
+                               unsigned int planeno,
+                               FAR struct lcd_planeinfo_s *pinfo);
+
+/* LCD Specific Controls */
+
+static int apa102_getpower(FAR struct lcd_dev_s *dev);
+static int apa102_setpower(FAR struct lcd_dev_s *dev, int power);
+static int apa102_getcontrast(FAR struct lcd_dev_s *dev);
+static int apa102_setcontrast(FAR struct lcd_dev_s *dev,
+                               unsigned int contrast);
+
+/* Initialization */
+
+static inline void up_clear(FAR struct apa102_dev_s  *priv);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* This is working memory allocated by the LCD driver for each LCD device
+ * and for each color plane.  This memory will hold one raster line of data.
+ * The size of the allocated run buffer must therefore be at least
+ * (bpp * xres / 8).  Actual alignment of the buffer must conform to the
+ * bitwidth of the underlying pixel type.
+ *
+ * If there are multiple planes, they may share the same working buffer
+ * because different planes will not be operate on concurrently.  However,
+ * if there are multiple LCD devices, they must each have unique run buffers.
+ */
+
+static uint8_t g_runbuffer[APA102_LUT_SIZE];
+
+/* This structure describes the overall LCD video controller */
+
+static const struct fb_videoinfo_s g_videoinfo =
+{
+  APA102_COLORFMT,    /* Color format: RGB16-565: RRRR RGGG GGGB BBBB */
+  APA102_XRES,        /* Horizontal resolution in pixel columns */
+  APA102_YRES,        /* Vertical resolution in pixel rows */
+  1,                  /* Number of color planes supported */
+};
+
+/* This is the standard, NuttX Plane information object */
+
+static const struct lcd_planeinfo_s g_planeinfo =
+{
+  .putrun = apa102_putrun,              /* Put a run into LCD memory */
+  .getrun = apa102_getrun,              /* Get a run from LCD memory */
+  .buffer = (FAR uint8_t *)g_runbuffer, /* Run scratch buffer */
+  .bpp    = APA102_BPP,                 /* Bits-per-pixel */
+};
+
+/* This is the standard, NuttX LCD driver object */
+
+static struct apa102_dev_s g_apa102dev =
+{
+  /* struct lcd_dev_s */
+
+  {
+    /* LCD Configuration */
+
+    apa102_getvideoinfo,
+    apa102_getplaneinfo,
+
+#ifdef CONFIG_FB_CMAP
+    /* LCD RGB Mapping -- Not supported */
+
+    NULL,
+    NULL,
+#endif
+
+#ifdef CONFIG_FB_HWCURSOR
+    /* Cursor Controls -- Not supported */
+
+    NULL,
+    NULL,
+#endif
+
+    /* LCD Specific Controls */
+
+    apa102_getpower,
+    apa102_setpower,
+    apa102_getcontrast,
+    apa102_setcontrast,
+  },
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: rgb565_apa102
+ *
+ * Description:
+ *   Convert RGB565 to APA102 RGB888 format
+ *
+ ****************************************************************************/
+
+static struct apa102_ledstrip_s rgb565_apa102(uint16_t rgb565)
+{
+  struct apa102_ledstrip_s led;
+  led.red    = (rgb565 & 0b1111100000000000) >> 8;
+  led.green  = (rgb565 & 0b11111100000) >> 3;
+  led.blue   = (rgb565 & 0b11111) << 3;
+  led.bright = 0;
+  return led;
+}
+
+/****************************************************************************
+ * Name: apa102_rgb565
+ *
+ * Description:
+ *   Convert APA102 RGB888 to RGB565 format
+ *
+ ****************************************************************************/
+
+static uint16_t apa102_rgb565(struct apa102_ledstrip_s led)
+{
+  uint16_t pixel;
+
+  pixel  = (led.red & 0b11111000) << 8;
+  pixel |= (led.green & 0b11111100) << 3;
+  pixel |= (led.blue & 0b11111000) >> 3;
+  return pixel;
+}
+
+/****************************************************************************
+ * Name: apa102_configspi
+ *
+ * Description:
+ *   Set the SPI bus configuration
+ *
+ ****************************************************************************/
+
+static inline void apa102_configspi(FAR struct spi_dev_s *spi)
+{
+  /* Configure SPI for the APA102 */
+
+  SPI_SETMODE(spi, SPIDEV_MODE0);
+  SPI_SETBITS(spi, 8);
+  SPI_HWFEATURES(spi, 0);
+  SPI_SETFREQUENCY(spi, APA102_SPI_MAXFREQUENCY);
+}
+
+/****************************************************************************
+ * Name: apa102_write32
+ *
+ * Description:
+ *   Write 32-bit to APA102
+ *
+ ****************************************************************************/
+
+static inline void apa102_write32(FAR struct apa102_dev_s *priv,
+                                  FAR uint32_t value)
+{
+  /* If SPI bus is shared then lock and configure it */
+
+  SPI_LOCK(priv->spi, true);
+
+  /* Note: APA102 doesn't use chip select */
+
+  /* Send 32 bits (4 bytes) */
+
+  SPI_SEND(priv->spi, (value & 0xff));
+  SPI_SEND(priv->spi, ((value & 0xff00) >> 8));
+  SPI_SEND(priv->spi, ((value & 0xff0000) >> 16));
+  SPI_SEND(priv->spi, ((value & 0xff000000) >> 24));
+
+  /* Unlock bus */
+
+  SPI_LOCK(priv->spi, false);
+}
+
+/****************************************************************************
+ * Name:  apa102_putrun
+ *
+ * Description:
+ *   This method can be used to write a partial raster line to the LCD:
+ *
+ *   dev     - The lcd device
+ *   row     - Starting row to write to (range: 0 <= row < yres)
+ *   col     - Starting column to write to (range: 0 <= col <= xres-npixels)
+ *   buffer  - The buffer containing the run to be written to the LCD
+ *   npixels - The number of pixels to write to the LCD
+ *             (range: 0 < npixels <= xres-col)
+ *
+ ****************************************************************************/
+
+static int apa102_putrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                          fb_coord_t col, FAR const uint8_t *buffer,
+                          size_t npixels)
+{
+  /* Because of this line of code, we will only be able to support a single
+   * APA102 device .
+   */
+
+  FAR struct apa102_dev_s *priv = (FAR struct apa102_dev_s *)dev;
+  int i;
+  int pixlen;
+
+  ginfo("row: %d col: %d npixels: %d\n", row, col, npixels);
+  DEBUGASSERT(buffer && ((uintptr_t)buffer & 1) == 0);
+
+  /* Clip the run to the display */
+
+  pixlen = npixels;
+  if ((unsigned int)col + (unsigned int)pixlen > (unsigned int)APA102_XRES)
+    {
+      pixlen = (int)APA102_XRES - (int)col;
+    }
+
+  /* Verify that some portion of the run remains on the display */
+
+  if (pixlen <= 0 || row > APA102_YRES)
+    {
+      return OK;
+    }
+
+  /* Convert rgb565 to APA102 LED values */
+
+  for (i = 0; i < pixlen; i++)
+    {
+      uint16_t *ptr = (uint16_t *)buffer;
+
+      priv->fb[(row * APA102_XRES) + col + i] = rgb565_apa102(*ptr++);
+    }
+
+  /* Confirm that SPI is configured correctly */
+
+  apa102_configspi(priv->spi);
+
+  /* Send a start of frame */
+
+  apa102_write32(priv, APA102_START_FRAME);
+
+  /* Send all LEDs values in the matrix */
+
+  for (i = 0; i < (APA102_XRES * APA102_YRES); i++)
+    {
+      uint32_t *led = (uint32_t *) &priv->fb[i];
+
+      /* Then transfer 4 bytes per LED */
+
+      apa102_write32(priv, (uint32_t) (*led | APA102_HEADER_FRAME));
+    }
+
+  /* Send an end of frame */
+
+  apa102_write32(priv, APA102_END_FRAME);
+
+  for (i = 0; i < (1 + APA102_XRES * APA102_YRES / 32); i++)
+    {
+      apa102_write32(priv, 0);
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getrun
+ *
+ * Description:
+ *   This method can be used to read a partial raster line from the LCD:
+ *
+ *  dev     - The lcd device
+ *  row     - Starting row to read from (range: 0 <= row < yres)
+ *  col     - Starting column to read read (range: 0 <= col <= xres-npixels)
+ *  buffer  - The buffer in which to return the run read from the LCD
+ *  npixels - The number of pixels to read from the LCD
+ *            (range: 0 < npixels <= xres-col)
+ *
+ ****************************************************************************/
+
+static int apa102_getrun(FAR struct lcd_dev_s *dev, fb_coord_t row,
+                          fb_coord_t col, FAR uint8_t *buffer,
+                          size_t npixels)
+{
+  /* Because of this line of code, we will only be able to support a single
+   * APA102 device.
+   */
+
+  FAR struct apa102_dev_s *priv = (FAR struct apa102_dev_s *)dev;
+  int i;
+  int pixlen;
+
+  ginfo("row: %d col: %d npixels: %d\n", row, col, npixels);
+  DEBUGASSERT(buffer);
+
+  /* Clip the run to the display */
+
+  pixlen = npixels;
+  if ((unsigned int)col + (unsigned int)pixlen > (unsigned int)APA102_XRES)
+    {
+      pixlen = (int)APA102_XRES - (int)col;
+    }
+
+  /* Verify that some portion of the run is actually the display */
+
+  if (pixlen <= 0 || row > APA102_YRES)
+    {
+      return -EINVAL;
+    }
+
+  for (i = 0; i < pixlen; i++)
+    {
+      uint16_t *ptr = (uint16_t *) buffer;
+
+      *ptr++ = apa102_rgb565(priv->fb[(row * APA102_XRES) + col + i]);
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getvideoinfo
+ *
+ * Description:
+ *   Get information about the LCD video controller configuration.
+ *
+ ****************************************************************************/
+
+static int apa102_getvideoinfo(FAR struct lcd_dev_s *dev,
+                              FAR struct fb_videoinfo_s *vinfo)
+{
+  DEBUGASSERT(dev && vinfo);
+
+  ginfo("fmt: %d xres: %d yres: %d nplanes: %d\n",
+        g_videoinfo.fmt, g_videoinfo.xres, g_videoinfo.yres,
+        g_videoinfo.nplanes);
+
+  memcpy(vinfo, &g_videoinfo, sizeof(struct fb_videoinfo_s));
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getplaneinfo
+ *
+ * Description:
+ *   Get information about the configuration of each LCD color plane.
+ *
+ ****************************************************************************/
+
+static int apa102_getplaneinfo(FAR struct lcd_dev_s *dev,
+                                unsigned int planeno,
+                                FAR struct lcd_planeinfo_s *pinfo)
+{
+  DEBUGASSERT(dev && pinfo && planeno == 0);
+
+  ginfo("planeno: %d bpp: %d\n", planeno, g_planeinfo.bpp);
+
+  memcpy(pinfo, &g_planeinfo, sizeof(struct lcd_planeinfo_s));
+  pinfo->dev = dev;
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name:  apa102_getpower
+ *
+ * Description:
+ *   Get the LCD panel power status (0: full off - CONFIG_LCD_MAXPOWER: full
+ *   on). On backlit LCDs, this setting may correspond to the backlight
+ *   setting.
+ *
+ ****************************************************************************/
+
+static int apa102_getpower(struct lcd_dev_s *dev)
+{
+  struct apa102_dev_s *priv = (struct apa102_dev_s *)dev;
+
+  DEBUGASSERT(priv);
+  ginfo("powered: %d\n", priv->powered);
+
+  return priv->powered;
+}
+
+/****************************************************************************
+ * Name:  apa102_setpower
+ *
+ * Description:
+ *   Enable/disable LCD panel power (0: full off - CONFIG_LCD_MAXPOWER: full
+ *   on). On backlit LCDs, this setting may correspond to the backlight
+ *   setting.
+ *
+ ****************************************************************************/
+
+static int apa102_setpower(struct lcd_dev_s *dev, int power)

Review Comment:
   ```suggestion
   static int apa102_setpower(FAR struct lcd_dev_s *dev, int power)
   ```



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