[PATCH v5 2/4] iio: accel: adxl345: Use I2C regmap instead of direct I2C access

Eva Rachel Retuya
2017-02-28T02:44:36Z

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 <eraretuya@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
---
Changes from v4:
* Add Andy's Reviewed-by tag

Changes from v3:
* Keep intact I2C client structure which was deleted from v3
* Make use of regmap_get_device to retrieve struct device, use these for
debugging prints instead of &client->dev.

drivers/iio/accel/Kconfig | 1 +
drivers/iio/accel/adxl345.c | 66 +++++++++++++++++++++++++++++----------------
2 files changed, 44 insertions(+), 23 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..bec8bec 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>

@@ -45,10 +46,15 @@
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 +76,7 @@ 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 +85,12 @@ 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;
@@ -104,37 +112,50 @@ static int adxl345_probe(struct i2c_client *client,
{
struct adxl345_data *data;
struct iio_dev *indio_dev;
+ struct device *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);
+ }
+
+ dev = regmap_get_device(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);
+ dev_err(dev, "Error reading device ID: %d\n", ret);
return ret;
}

- if (ret != ADXL345_DEVID) {
- dev_err(&client->dev, "Invalid device ID: %d\n", ret);
+ if (regval != ADXL345_DEVID) {
+ dev_err(dev, "Invalid device ID: %x, expected %x\n",
+ regval, ADXL345_DEVID);
return -ENODEV;
}

- indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;

data = iio_priv(indio_dev);
- i2c_set_clientdata(client, indio_dev);
- data->client = client;
+ dev_set_drvdata(dev, indio_dev);
+ 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);
+ dev_err(dev, "Failed to set data range: %d\n", ret);
return ret;
}

- indio_dev->dev.parent = &client->dev;
+ indio_dev->dev.parent = dev;
indio_dev->name = id->name;
indio_dev->info = &adxl345_info;
indio_dev->modes = INDIO_DIRECT_MODE;
@@ -142,19 +163,18 @@ 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);
+ dev_err(dev, "Failed to enable measurement mode: %d\n", ret);
return ret;
}

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);
+ dev_err(dev, "iio_device_register failed: %d\n", ret);
+ regmap_write(data->regmap, ADXL345_REG_POWER_CTL,
+ ADXL345_POWER_CTL_STANDBY);
}

return ret;
@@ -167,8 +187,8 @@ 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