iio: imu: st_lsm6dsx: add regmap API support

Introduce regmap API support to access to i2c/spi bus instead of
using a custom support. Set max bulk read to
(32 / SAMPLE_SIZE) * SAMPLE_SIZE since spi_write_then_read() used in
regmap_spi indicates that is the max buffer length to use in order to
avoid a kmalloc for each bus access.
Remove lock mutex since concurrency is already managed by regmap API

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 6 insertions, 25 deletions

diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h
index cebc6bd31b79..ccbe44cef41a 100644
--- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h
+++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h
@@ -29,21 +29,9 @@ enum st_lsm6dsx_hw_id {
 
 #define ST_LSM6DSX_CHAN_SIZE		2
 #define ST_LSM6DSX_SAMPLE_SIZE		6
-
-#if defined(CONFIG_SPI_MASTER)
-#define ST_LSM6DSX_RX_MAX_LENGTH	256
-#define ST_LSM6DSX_TX_MAX_LENGTH	8
-
-struct st_lsm6dsx_transfer_buffer {
-	u8 rx_buf[ST_LSM6DSX_RX_MAX_LENGTH];
-	u8 tx_buf[ST_LSM6DSX_TX_MAX_LENGTH] ____cacheline_aligned;
-};
-#endif /* CONFIG_SPI_MASTER */
-
-struct st_lsm6dsx_transfer_function {
-	int (*read)(struct device *dev, u8 addr, int len, u8 *data);
-	int (*write)(struct device *dev, u8 addr, int len, u8 *data);
-};
+#define ST_LSM6DSX_MAX_WORD_LEN		((32 / ST_LSM6DSX_SAMPLE_SIZE) * \
+					 ST_LSM6DSX_SAMPLE_SIZE)
+#define ST_LSM6DSX_SHIFT_VAL(val, mask)	(((val) << __ffs(mask)) & (mask))
 
 struct st_lsm6dsx_reg {
 	u8 addr;
@@ -127,8 +115,8 @@ struct st_lsm6dsx_sensor {
 /**
  * struct st_lsm6dsx_hw - ST IMU MEMS hw instance
  * @dev: Pointer to instance of struct device (I2C or SPI).
+ * @regmap: Register map of the device.
  * @irq: Device interrupt line (I2C or SPI).
- * @lock: Mutex to protect read and write operations.
  * @fifo_lock: Mutex to prevent concurrent access to the hw FIFO.
  * @conf_lock: Mutex to prevent concurrent FIFO configuration update.
  * @fifo_mode: FIFO operating mode supported by the device.
@@ -136,14 +124,12 @@ struct st_lsm6dsx_sensor {
  * @sip: Total number of samples (acc/gyro) in a given pattern.
  * @iio_devs: Pointers to acc/gyro iio_dev instances.
  * @settings: Pointer to the specific sensor settings in use.
- * @tf: Transfer function structure used by I/O operations.
- * @tb: Transfer buffers used by SPI I/O operations.
  */
 struct st_lsm6dsx_hw {
 	struct device *dev;
+	struct regmap *regmap;
 	int irq;
 
-	struct mutex lock;
 	struct mutex fifo_lock;
 	struct mutex conf_lock;
 
@@ -154,17 +140,12 @@ struct st_lsm6dsx_hw {
 	struct iio_dev *iio_devs[ST_LSM6DSX_ID_MAX];
 
 	const struct st_lsm6dsx_settings *settings;
-
-	const struct st_lsm6dsx_transfer_function *tf;
-#if defined(CONFIG_SPI_MASTER)
-	struct st_lsm6dsx_transfer_buffer tb;
-#endif /* CONFIG_SPI_MASTER */
 };
 
 extern const struct dev_pm_ops st_lsm6dsx_pm_ops;
 
 int st_lsm6dsx_probe(struct device *dev, int irq, int hw_id, const char *name,
-		     const struct st_lsm6dsx_transfer_function *tf_ops);
+		     struct regmap *regmap);
 int st_lsm6dsx_sensor_enable(struct st_lsm6dsx_sensor *sensor);
 int st_lsm6dsx_sensor_disable(struct st_lsm6dsx_sensor *sensor);
 int st_lsm6dsx_fifo_setup(struct st_lsm6dsx_hw *hw);