iio: imu: st_lsm6dsx: reset hw ts after resume

Reset hw time samples generator after system resume in order to avoid
disalignment between system and device time reference since FIFO
batching and time samples generator are disabled during suspend.

Fixes: 21345107 ("iio: imu: st_lsm6dsx: add hw timestamp support")
Tested-by: Sean Nyekjaer <sean@geanix.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h

@@ -436,8 +436,7 @@ int st_lsm6dsx_update_watermark(struct st_lsm6dsx_sensor *sensor,
 				u16 watermark);
 int st_lsm6dsx_update_fifo(struct st_lsm6dsx_sensor *sensor, bool enable);
 int st_lsm6dsx_flush_fifo(struct st_lsm6dsx_hw *hw);
-int st_lsm6dsx_set_fifo_mode(struct st_lsm6dsx_hw *hw,
-			     enum st_lsm6dsx_fifo_mode fifo_mode);
+int st_lsm6dsx_resume_fifo(struct st_lsm6dsx_hw *hw);
 int st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw *hw);
 int st_lsm6dsx_read_tagged_fifo(struct st_lsm6dsx_hw *hw);
 int st_lsm6dsx_check_odr(struct st_lsm6dsx_sensor *sensor, u32 odr, u8 *val);

drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c

@@ -184,8 +184,8 @@ static int st_lsm6dsx_update_decimators(struct st_lsm6dsx_hw *hw)
 	return err;
 }
 
-int st_lsm6dsx_set_fifo_mode(struct st_lsm6dsx_hw *hw,
-			     enum st_lsm6dsx_fifo_mode fifo_mode)
+static int st_lsm6dsx_set_fifo_mode(struct st_lsm6dsx_hw *hw,
+				    enum st_lsm6dsx_fifo_mode fifo_mode)
 {
 	unsigned int data;
 
@@ -302,6 +302,18 @@ static int st_lsm6dsx_reset_hw_ts(struct st_lsm6dsx_hw *hw)
 	return 0;
 }
 
+int st_lsm6dsx_resume_fifo(struct st_lsm6dsx_hw *hw)
+{
+	int err;
+
+	/* reset hw ts counter */
+	err = st_lsm6dsx_reset_hw_ts(hw);
+	if (err < 0)
+		return err;
+
+	return st_lsm6dsx_set_fifo_mode(hw, ST_LSM6DSX_FIFO_CONT);
+}
+
 /*
  * Set max bulk read to ST_LSM6DSX_MAX_WORD_LEN/ST_LSM6DSX_MAX_TAGGED_WORD_LEN
  * in order to avoid a kmalloc for each bus access
@@ -675,12 +687,7 @@ int st_lsm6dsx_update_fifo(struct st_lsm6dsx_sensor *sensor, bool enable)
 		goto out;
 
 	if (fifo_mask) {
-		/* reset hw ts counter */
-		err = st_lsm6dsx_reset_hw_ts(hw);
-		if (err < 0)
-			goto out;
-
-		err = st_lsm6dsx_set_fifo_mode(hw, ST_LSM6DSX_FIFO_CONT);
+		err = st_lsm6dsx_resume_fifo(hw);
 		if (err < 0)
 			goto out;
 	}

drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c

@@ -2457,7 +2457,7 @@ static int __maybe_unused st_lsm6dsx_resume(struct device *dev)
 	}
 
 	if (hw->fifo_mask)
-		err = st_lsm6dsx_set_fifo_mode(hw, ST_LSM6DSX_FIFO_CONT);
+		err = st_lsm6dsx_resume_fifo(hw);
 
 	return err;
 }