[PATCH v2 4/7] iio: inv_mpu6050: Cache non-volatile bits of user_ctrl

[Crestez Dan Leonard]

Signed-off-by: Crestez Dan Leonard <leonard.crestez@xxxxxxxxx>
---
 drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h     | 2 ++
 drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c    | 9 ++++++---
 drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c | 4 +++-
 3 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
index 297b0ef..bd2c0fd 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
@@ -80,6 +80,7 @@ enum inv_devices {
  *  @enable:		master enable state.
  *  @accl_fifo_enable:	enable accel data output
  *  @gyro_fifo_enable:	enable gyro data output
+ *  @user_ctrl:		The non-volatile bits of user_ctrl
  *  @fifo_rate:		FIFO update rate.
  */
 struct inv_mpu6050_chip_config {
@@ -89,6 +90,7 @@ struct inv_mpu6050_chip_config {
 	unsigned int enable:1;
 	unsigned int accl_fifo_enable:1;
 	unsigned int gyro_fifo_enable:1;
+	u8 user_ctrl;
 	u16 fifo_rate;
 };
 
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
index 3fc0b71..56ee1e2 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
@@ -53,13 +53,15 @@ int inv_reset_fifo(struct iio_dev *indio_dev)
 	if (result)
 		goto reset_fifo_fail;
 	/* disable fifo reading */
-	result = regmap_write(st->map, st->reg->user_ctrl, 0);
+	st->chip_config.user_ctrl &= ~INV_MPU6050_BIT_FIFO_EN;
+	result = regmap_write(st->map, st->reg->user_ctrl,
+			      st->chip_config.user_ctrl);
 	if (result)
 		goto reset_fifo_fail;
 
 	/* reset FIFO*/
 	result = regmap_write(st->map, st->reg->user_ctrl,
-			      INV_MPU6050_BIT_FIFO_RST);
+			      st->chip_config.user_ctrl | INV_MPU6050_BIT_FIFO_RST);
 	if (result)
 		goto reset_fifo_fail;
 
@@ -76,8 +78,9 @@ int inv_reset_fifo(struct iio_dev *indio_dev)
 			return result;
 	}
 	/* enable FIFO reading and I2C master interface*/
+	st->chip_config.user_ctrl |= INV_MPU6050_BIT_FIFO_EN;
 	result = regmap_write(st->map, st->reg->user_ctrl,
-			      INV_MPU6050_BIT_FIFO_EN);
+			      st->chip_config.user_ctrl);
 	if (result)
 		goto reset_fifo_fail;
 	/* enable sensor output to FIFO */
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c
index 1a6bad3..fc55923 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c
@@ -74,7 +74,9 @@ static int inv_mpu6050_set_enable(struct iio_dev *indio_dev, bool enable)
 		if (result)
 			return result;
 
-		result = regmap_write(st->map, st->reg->user_ctrl, 0);
+		st->chip_config.user_ctrl &= ~INV_MPU6050_BIT_FIFO_EN;
+		result = regmap_write(st->map, st->reg->user_ctrl,
+				      st->chip_config.user_ctrl);
 		if (result)
 			return result;
 
-- 
2.5.5