[mynewt-core] 05/06: hw/drivers/ms5840: Fix sensor register read

[an...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

andk pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/mynewt-core.git

commit b378268598fef3d53a283ac23099e888947d8721
Author: Andrzej Kaczmarek <an...@codecoup.pl>
AuthorDate: Mon Jan 7 12:00:09 2019 +0100

    hw/drivers/ms5840: Fix sensor register read
    
    With i2cn, we need to make sure that before retrying read we also
    perform write as otherwise we may read subsequent registers instead of
    those we wanted to read thus invalid values will be reported.
---
 hw/drivers/sensors/ms5840/src/ms5840.c | 35 ++++++++++------------------------
 1 file changed, 10 insertions(+), 25 deletions(-)

diff --git a/hw/drivers/sensors/ms5840/src/ms5840.c b/hw/drivers/sensors/ms5840/src/ms5840.c
index 7892601..0038a08 100644
--- a/hw/drivers/sensors/ms5840/src/ms5840.c
+++ b/hw/drivers/sensors/ms5840/src/ms5840.c
@@ -379,12 +379,15 @@ ms5840_readlen(struct sensor_itf *itf, uint8_t addr, uint8_t *buffer,
 #if MYNEWT_VAL(BUS_DRIVER_PRESENT)
     rc = bus_node_simple_write_read_transact(itf->si_dev, &addr, 1, buffer, len);
 #else
-    uint8_t payload[3] = {addr, 0, 0};
-
-    struct hal_i2c_master_data data_struct = {
+    struct hal_i2c_master_data wdata = {
         .address = itf->si_addr,
         .len = 1,
-        .buffer = payload
+        .buffer = &addr,
+    };
+    struct hal_i2c_master_data rdata = {
+        .address = itf->si_addr,
+        .len = len,
+        .buffer = buffer,
     };
 
     /* Clear the supplied buffer */
@@ -395,32 +398,14 @@ ms5840_readlen(struct sensor_itf *itf, uint8_t addr, uint8_t *buffer,
         return rc;
     }
 
-    /* Command write */
-    rc = i2cn_master_write(itf->si_num, &data_struct, MYNEWT_VAL(MS5840_I2C_TIMEOUT_TICKS), 1,
-                           MYNEWT_VAL(MS5840_I2C_RETRIES));
-    if (rc) {
-        MS5840_LOG(ERROR, "I2C read command write failed at address 0x%02X\n",
-                   data_struct.address);
-        STATS_INC(g_ms5840stats, write_errors);
-        goto err;
-    }
-
-    /* Read len bytes back */
-    memset(payload, 0, sizeof(payload));
-    data_struct.len = len;
-    rc = i2cn_master_read(itf->si_num, &data_struct, MYNEWT_VAL(MS5840_I2C_TIMEOUT_TICKS), 1,
-                          MYNEWT_VAL(MS5840_I2C_RETRIES));
+    rc = i2cn_master_write_read_transact(itf->si_num, &wdata, &rdata, MYNEWT_VAL(MS5840_I2C_TIMEOUT_TICKS) * 2,
+                                         1, MYNEWT_VAL(MS5840_I2C_RETRIES));
     if (rc) {
         MS5840_LOG(ERROR, "Failed to read from 0x%02X:0x%02X\n",
-                   data_struct.address, addr);
+                   itf->si_addr, addr);
         STATS_INC(g_ms5840stats, read_errors);
-        goto err;
     }
 
-    /* Copy the I2C results into the supplied buffer */
-    memcpy(buffer, payload, len);
-
-err:
     sensor_itf_unlock(itf);
 #endif