FIXUP: fix lsm6dsm driver specific data type declaration

accelgyro_lsm6dsm driver use lsm6dsm_data as its driver specific
data type rather than stprivate_data. Wrong data type will lead
to random corrupted runtime data.

Signed-off-by: Paul Ma <magf@bitland.corp-partner.google.com>

BRANCH=none
BUG=b:110013316
TEST=make buildall -j

Change-Id: I50e0da293921c2662e97aa6f47c83519609186b5
Reviewed-on: https://chromium-review.googlesource.com/1105797
Commit-Ready: Paul Ma <magf@bitland.corp-partner.google.com>
Tested-by: Paul Ma <magf@bitland.corp-partner.google.com>
Reviewed-by: Jett Rink <jettrink@chromium.org>

1 files changed, 32 insertions, 0 deletions

diff --git a/driver/accelgyro_lsm6dsm.c b/driver/accelgyro_lsm6dsm.c
index d0ef49b906..683b2ed616 100644
--- a/driver/accelgyro_lsm6dsm.c
+++ b/driver/accelgyro_lsm6dsm.c
@@ -337,6 +337,14 @@ static int set_range(const struct motion_sensor_t *s, int range, int rnd)
 {
 	int err;
 	uint8_t ctrl_reg, reg_val;
+	/*
+	 * Since 'stprivate_data a_data;' is the first member of lsm6dsm_data,
+	 * the address of lsm6dsm_data is the same as a_data's. Using this
+	 * fact, we can do the following conversion. This conversion is equal
+	 * to:
+	 *     struct lsm6dsm_data *lsm_data = s->drv_data;
+	 *     struct stprivate_data *data = &lsm_data->a_data;
+	 */
 	struct stprivate_data *data = s->drv_data;
 	int newrange = range;
 
@@ -381,6 +389,14 @@ static int set_range(const struct motion_sensor_t *s, int range, int rnd)
  */
 static int get_range(const struct motion_sensor_t *s)
 {
+	/*
+	 * Since 'stprivate_data a_data;' is the first member of lsm6dsm_data,
+	 * the address of lsm6dsm_data is the same as a_data's. Using this
+	 * fact, we can do the following conversion. This conversion is equal
+	 * to:
+	 *     struct lsm6dsm_data *lsm_data = s->drv_data;
+	 *     struct stprivate_data *data = &lsm_data->a_data;
+	 */
 	struct stprivate_data *data = s->drv_data;
 
 	if (s->type == MOTIONSENSE_TYPE_ACCEL)
@@ -399,6 +415,14 @@ static int get_range(const struct motion_sensor_t *s)
 static int set_data_rate(const struct motion_sensor_t *s, int rate, int rnd)
 {
 	int ret, normalized_rate;
+	/*
+	 * Since 'stprivate_data a_data;' is the first member of lsm6dsm_data,
+	 * the address of lsm6dsm_data is the same as a_data's. Using this
+	 * fact, we can do the following conversion. This conversion is equal
+	 * to:
+	 *     struct lsm6dsm_data *lsm_data = s->drv_data;
+	 *     struct stprivate_data *data = &lsm_data->a_data;
+	 */
 	struct stprivate_data *data = s->drv_data;
 	uint8_t ctrl_reg, reg_val;
 
@@ -491,6 +515,14 @@ static int read(const struct motion_sensor_t *s, vector_3_t v)
 static int init(const struct motion_sensor_t *s)
 {
 	int ret = 0, tmp;
+	/*
+	 * Since 'stprivate_data a_data;' is the first member of lsm6dsm_data,
+	 * the address of lsm6dsm_data is the same as a_data's. Using this
+	 * fact, we can do the following conversion. This conversion is equal
+	 * to:
+	 *     struct lsm6dsm_data *lsm_data = s->drv_data;
+	 *     struct stprivate_data *data = &lsm_data->a_data;
+	 */
 	struct stprivate_data *data = s->drv_data;
 
 	ret = st_raw_read8(s->port, s->addr, LSM6DSM_WHO_AM_I_REG, &tmp);