iio: make st_sensors drivers use regmap

This patch is meant to replace the i2c/spi transfer functions with
regmap. SPI framework requires DMA safe buffers so let's add GFP_DMA
flag for memory allocation used by bulk_read functions.

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

2 files changed, 5 insertions, 39 deletions

diff --git a/include/linux/iio/common/st_sensors.h b/include/linux/iio/common/st_sensors.h
index 566b955e2980..28fc1f9fa7d5 100644
--- a/include/linux/iio/common/st_sensors.h
+++ b/include/linux/iio/common/st_sensors.h
@@ -16,6 +16,7 @@
 #include <linux/iio/trigger.h>
 #include <linux/bitops.h>
 #include <linux/regulator/consumer.h>
+#include <linux/regmap.h>
 
 #include <linux/platform_data/st_sensors_pdata.h>
 
@@ -170,36 +171,6 @@ struct st_sensor_data_ready_irq {
 };
 
 /**
- * struct st_sensor_transfer_buffer - ST sensor device I/O buffer
- * @buf_lock: Mutex to protect rx and tx buffers.
- * @tx_buf: Buffer used by SPI transfer function to send data to the sensors.
- *	This buffer is used to avoid DMA not-aligned issue.
- * @rx_buf: Buffer used by SPI transfer to receive data from sensors.
- *	This buffer is used to avoid DMA not-aligned issue.
- */
-struct st_sensor_transfer_buffer {
-	struct mutex buf_lock;
-	u8 rx_buf[ST_SENSORS_RX_MAX_LENGTH];
-	u8 tx_buf[ST_SENSORS_TX_MAX_LENGTH] ____cacheline_aligned;
-};
-
-/**
- * struct st_sensor_transfer_function - ST sensor device I/O function
- * @read_byte: Function used to read one byte.
- * @write_byte: Function used to write one byte.
- * @read_multiple_byte: Function used to read multiple byte.
- */
-struct st_sensor_transfer_function {
-	int (*read_byte) (struct st_sensor_transfer_buffer *tb,
-				struct device *dev, u8 reg_addr, u8 *res_byte);
-	int (*write_byte) (struct st_sensor_transfer_buffer *tb,
-				struct device *dev, u8 reg_addr, u8 data);
-	int (*read_multiple_byte) (struct st_sensor_transfer_buffer *tb,
-		struct device *dev, u8 reg_addr, int len, u8 *data,
-							bool multiread_bit);
-};
-
-/**
  * struct st_sensor_settings - ST specific sensor settings
  * @wai: Contents of WhoAmI register.
  * @wai_addr: The address of WhoAmI register.
@@ -242,16 +213,14 @@ struct st_sensor_settings {
  * @current_fullscale: Maximum range of measure by the sensor.
  * @vdd: Pointer to sensor's Vdd power supply
  * @vdd_io: Pointer to sensor's Vdd-IO power supply
+ * @regmap: Pointer to specific sensor regmap configuration.
  * @enabled: Status of the sensor (false->off, true->on).
- * @multiread_bit: Use or not particular bit for [I2C/SPI] multiread.
  * @buffer_data: Data used by buffer part.
  * @odr: Output data rate of the sensor [Hz].
  * num_data_channels: Number of data channels used in buffer.
  * @drdy_int_pin: Redirect DRDY on pin 1 (1) or pin 2 (2).
  * @int_pin_open_drain: Set the interrupt/DRDY to open drain.
  * @get_irq_data_ready: Function to get the IRQ used for data ready signal.
- * @tf: Transfer function structure used by I/O operations.
- * @tb: Transfer buffers and mutex used by I/O operations.
  * @edge_irq: the IRQ triggers on edges and need special handling.
  * @hw_irq_trigger: if we're using the hardware interrupt on the sensor.
  * @hw_timestamp: Latest timestamp from the interrupt handler, when in use.
@@ -264,9 +233,9 @@ struct st_sensor_data {
 	struct st_sensor_fullscale_avl *current_fullscale;
 	struct regulator *vdd;
 	struct regulator *vdd_io;
+	struct regmap *regmap;
 
 	bool enabled;
-	bool multiread_bit;
 
 	char *buffer_data;
 
@@ -278,9 +247,6 @@ struct st_sensor_data {
 
 	unsigned int (*get_irq_data_ready) (struct iio_dev *indio_dev);
 
-	const struct st_sensor_transfer_function *tf;
-	struct st_sensor_transfer_buffer tb;
-
 	bool edge_irq;
 	bool hw_irq_trigger;
 	s64 hw_timestamp;
diff --git a/include/linux/iio/common/st_sensors_i2c.h b/include/linux/iio/common/st_sensors_i2c.h
index 5ada89944698..01e424e2af4f 100644
--- a/include/linux/iio/common/st_sensors_i2c.h
+++ b/include/linux/iio/common/st_sensors_i2c.h
@@ -14,8 +14,8 @@
 #include <linux/iio/common/st_sensors.h>
 #include <linux/of.h>
 
-void st_sensors_i2c_configure(struct iio_dev *indio_dev,
-		struct i2c_client *client, struct st_sensor_data *sdata);
+int st_sensors_i2c_configure(struct iio_dev *indio_dev,
+			     struct i2c_client *client);
 
 #ifdef CONFIG_ACPI
 int st_sensors_match_acpi_device(struct device *dev);