iio: imu: inv_mpu6050: fix user_ctrl register overwritten

When in spi mode, we are setting i2c disable bit in user_ctrl
register. But the register is overwritten after when turning fifo
on. So save user_ctrl init value and always use it when updating
the register.
Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/inv_mpu6050/inv_mpu_core.c

@@ -88,6 +88,7 @@ static const struct inv_mpu6050_chip_config chip_config_6050 = {
 	.gyro_fifo_enable = false,
 	.accl_fifo_enable = false,
 	.accl_fs = INV_MPU6050_FS_02G,
+	.user_ctrl = 0,
 };
 
 /* Indexed by enum inv_devices */
@@ -972,15 +973,15 @@ int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name,
 	if (result)
 		return result;
 
-	if (inv_mpu_bus_setup)
-		inv_mpu_bus_setup(indio_dev);
-
 	result = inv_mpu6050_init_config(indio_dev);
 	if (result) {
 		dev_err(dev, "Could not initialize device.\n");
 		return result;
 	}
 
+	if (inv_mpu_bus_setup)
+		inv_mpu_bus_setup(indio_dev);
+
 	dev_set_drvdata(dev, indio_dev);
 	indio_dev->dev.parent = dev;
 	/* name will be NULL when enumerated via ACPI */

drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h

@@ -97,6 +97,7 @@ struct inv_mpu6050_chip_config {
 	unsigned int accl_fifo_enable:1;
 	unsigned int gyro_fifo_enable:1;
 	u16 fifo_rate;
+	u8 user_ctrl;
 };
 
 /**

drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c

@@ -51,13 +51,14 @@ 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);
+	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);
+	d = st->chip_config.user_ctrl | INV_MPU6050_BIT_FIFO_RST;
+	result = regmap_write(st->map, st->reg->user_ctrl, d);
 	if (result)
 		goto reset_fifo_fail;
 
@@ -72,9 +73,9 @@ int inv_reset_fifo(struct iio_dev *indio_dev)
 		if (result)
 			return result;
 	}
-	/* enable FIFO reading and I2C master interface*/
-	result = regmap_write(st->map, st->reg->user_ctrl,
-			      INV_MPU6050_BIT_FIFO_EN);
+	/* enable FIFO reading */
+	d = st->chip_config.user_ctrl | INV_MPU6050_BIT_FIFO_EN;
+	result = regmap_write(st->map, st->reg->user_ctrl, d);
 	if (result)
 		goto reset_fifo_fail;
 	/* enable sensor output to FIFO */

drivers/iio/imu/inv_mpu6050/inv_mpu_spi.c

@@ -31,8 +31,9 @@ static int inv_mpu_i2c_disable(struct iio_dev *indio_dev)
 	if (ret)
 		return ret;
 
-	ret = regmap_write(st->map, INV_MPU6050_REG_USER_CTRL,
-			   INV_MPU6050_BIT_I2C_IF_DIS);
+	st->chip_config.user_ctrl |= INV_MPU6050_BIT_I2C_IF_DIS;
+	ret = regmap_write(st->map, st->reg->user_ctrl,
+			   st->chip_config.user_ctrl);
 	if (ret) {
 		inv_mpu6050_set_power_itg(st, false);
 		return ret;

drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c

@@ -76,7 +76,8 @@ static int inv_mpu6050_set_enable(struct iio_dev *indio_dev, bool enable)
 		if (result)
 			goto error_accl_off;
 
-		result = regmap_write(st->map, st->reg->user_ctrl, 0);
+		result = regmap_write(st->map, st->reg->user_ctrl,
+				      st->chip_config.user_ctrl);
 		if (result)
 			goto error_accl_off;