[PATCH 1/4] iio: accel: adxl345: Use I2C regmap instead of direct I2C access

[Eva Rachel Retuya]

Convert the driver to use regmap instead of I2C-specific functions. This
is done in preparation for splitting this driver into core and
I2C-specific code as well as introduction of SPI driver.

Signed-off-by: Eva Rachel Retuya <eraret...@gmail.com>
---
 drivers/iio/accel/Kconfig   |  1 +
 drivers/iio/accel/adxl345.c | 43 +++++++++++++++++++++++++++++++------------
 2 files changed, 32 insertions(+), 12 deletions(-)

diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index 2308bac..26b8614 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -9,6 +9,7 @@ config ADXL345
        tristate "Analog Devices ADXL345 3-Axis Digital Accelerometer Driver"
        depends on !(INPUT_ADXL34X=y || INPUT_ADXL34X=m)
        depends on I2C
+       select REGMAP_I2C
        help
          Say Y here if you want to build support for the Analog Devices
          ADXL345 3-axis digital accelerometer.
diff --git a/drivers/iio/accel/adxl345.c b/drivers/iio/accel/adxl345.c
index c34991f..a1fdf60 100644
--- a/drivers/iio/accel/adxl345.c
+++ b/drivers/iio/accel/adxl345.c
@@ -14,6 +14,7 @@
 
 #include <linux/i2c.h>
 #include <linux/module.h>
+#include <linux/regmap.h>
 
 #include <linux/iio/iio.h>
 
@@ -46,9 +47,15 @@ static const int adxl345_uscale = 38300;
 
 struct adxl345_data {
        struct i2c_client *client;
+       struct regmap *regmap;
        u8 data_range;
 };
 
+static const struct regmap_config adxl345_regmap_config = {
+       .reg_bits = 8,
+       .val_bits = 8,
+};
+
 #define ADXL345_CHANNEL(reg, axis) {                                   \
        .type = IIO_ACCEL,                                              \
        .modified = 1,                                                  \
@@ -70,6 +77,7 @@ static int adxl345_read_raw(struct iio_dev *indio_dev,
 {
        struct adxl345_data *data = iio_priv(indio_dev);
        int ret;
+       __le16 regval;
 
        switch (mask) {
        case IIO_CHAN_INFO_RAW:
@@ -78,11 +86,12 @@ static int adxl345_read_raw(struct iio_dev *indio_dev,
                 * ADXL345_REG_DATA(X0/Y0/Z0) contain the least significant byte
                 * and ADXL345_REG_DATA(X0/Y0/Z0) + 1 the most significant byte
                 */
-               ret = i2c_smbus_read_word_data(data->client, chan->address);
+               ret = regmap_bulk_read(data->regmap, chan->address, &regval,
+                                      sizeof(regval));
                if (ret < 0)
                        return ret;
 
-               *val = sign_extend32(ret, 12);
+               *val = sign_extend32(le16_to_cpu(regval), 12);
                return IIO_VAL_INT;
        case IIO_CHAN_INFO_SCALE:
                *val = 0;
@@ -104,15 +113,24 @@ static int adxl345_probe(struct i2c_client *client,
 {
        struct adxl345_data *data;
        struct iio_dev *indio_dev;
+       struct regmap *regmap;
        int ret;
+       u32 regval;
+
+       regmap = devm_regmap_init_i2c(client, &adxl345_regmap_config);
+       if (IS_ERR(regmap)) {
+               dev_err(&client->dev, "Error initializing regmap: %d\n",
+                       (int)PTR_ERR(regmap));
+               return PTR_ERR(regmap);
+       }
 
-       ret = i2c_smbus_read_byte_data(client, ADXL345_REG_DEVID);
+       ret = regmap_read(regmap, ADXL345_REG_DEVID, &regval);
        if (ret < 0) {
                dev_err(&client->dev, "Error reading device ID: %d\n", ret);
                return ret;
        }
 
-       if (ret != ADXL345_DEVID) {
+       if (regval != ADXL345_DEVID) {
                dev_err(&client->dev, "Invalid device ID: %d\n", ret);
                return -ENODEV;
        }
@@ -124,11 +142,12 @@ static int adxl345_probe(struct i2c_client *client,
        data = iio_priv(indio_dev);
        i2c_set_clientdata(client, indio_dev);
        data->client = client;
+       data->regmap = regmap;
        /* Enable full-resolution mode */
        data->data_range = ADXL345_DATA_FORMAT_FULL_RES;
 
-       ret = i2c_smbus_write_byte_data(data->client, ADXL345_REG_DATA_FORMAT,
-                                       data->data_range);
+       ret = regmap_write(data->regmap, ADXL345_REG_DATA_FORMAT,
+                          data->data_range);
        if (ret < 0) {
                dev_err(&client->dev, "Failed to set data range: %d\n", ret);
                return ret;
@@ -142,8 +161,8 @@ static int adxl345_probe(struct i2c_client *client,
        indio_dev->num_channels = ARRAY_SIZE(adxl345_channels);
 
        /* Enable measurement mode */
-       ret = i2c_smbus_write_byte_data(data->client, ADXL345_REG_POWER_CTL,
-                                       ADXL345_POWER_CTL_MEASURE);
+       ret = regmap_write(data->regmap, ADXL345_REG_POWER_CTL,
+                          ADXL345_POWER_CTL_MEASURE);
        if (ret < 0) {
                dev_err(&client->dev, "Failed to enable measurement mode: %d\n",
                        ret);
@@ -153,8 +172,8 @@ static int adxl345_probe(struct i2c_client *client,
        ret = iio_device_register(indio_dev);
        if (ret < 0) {
                dev_err(&client->dev, "iio_device_register failed: %d\n", ret);
-               i2c_smbus_write_byte_data(data->client, ADXL345_REG_POWER_CTL,
-                                         ADXL345_POWER_CTL_STANDBY);
+               regmap_write(data->regmap, ADXL345_REG_POWER_CTL,
+                            ADXL345_POWER_CTL_STANDBY);
        }
 
        return ret;
@@ -167,8 +186,8 @@ static int adxl345_remove(struct i2c_client *client)
 
        iio_device_unregister(indio_dev);
 
-       return i2c_smbus_write_byte_data(data->client, ADXL345_REG_POWER_CTL,
-                                        ADXL345_POWER_CTL_STANDBY);
+       return regmap_write(data->regmap, ADXL345_REG_POWER_CTL,
+                           ADXL345_POWER_CTL_STANDBY);
 }
 
 static const struct i2c_device_id adxl345_i2c_id[] = {
-- 
2.7.4