iio: light: al3320a: Implement regmap support

Modernize and clean up the driver using the regmap framework.

With the regmap implementation, the compiler produces
a significantly smaller module.

Size before: 72 kB
Size after:  58 kB

Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://patch.msgid.link/20250402-al3010-iio-regmap-v4-5-d189bea87261@ixit.cz
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

1 files changed, 48 insertions, 39 deletions

diff --git a/drivers/iio/light/al3320a.c b/drivers/iio/light/al3320a.c
index 86ed23461cee..31f5e033c386 100644
--- a/drivers/iio/light/al3320a.c
+++ b/drivers/iio/light/al3320a.c
@@ -15,6 +15,7 @@
 #include <linux/bitfield.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
+#include <linux/regmap.h>
 #include <linux/mod_devicetable.h>
 
 #include <linux/iio/iio.h>
@@ -57,8 +58,14 @@ static const int al3320a_scales[][2] = {
 	{0, 512000}, {0, 128000}, {0, 32000}, {0, 10000}
 };
 
+static const struct regmap_config al3320a_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = AL3320A_REG_HIGH_THRESH_HIGH,
+};
+
 struct al3320a_data {
-	struct i2c_client *client;
+	struct regmap *regmap;
 };
 
 static const struct iio_chan_spec al3320a_channels[] = {
@@ -80,50 +87,47 @@ static const struct attribute_group al3320a_attribute_group = {
 	.attrs = al3320a_attributes,
 };
 
-static int al3320a_set_pwr_on(struct i2c_client *client)
+static int al3320a_set_pwr_on(struct al3320a_data *data)
 {
-	return i2c_smbus_write_byte_data(client, AL3320A_REG_CONFIG, AL3320A_CONFIG_ENABLE);
+	return regmap_write(data->regmap, AL3320A_REG_CONFIG, AL3320A_CONFIG_ENABLE);
 }
 
 static void al3320a_set_pwr_off(void *_data)
 {
 	struct al3320a_data *data = _data;
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
 
-	i2c_smbus_write_byte_data(data->client, AL3320A_REG_CONFIG, AL3320A_CONFIG_DISABLE);
+	ret = regmap_write(data->regmap, AL3320A_REG_CONFIG, AL3320A_CONFIG_DISABLE);
+	if (ret)
+		dev_err(dev, "failed to write system register\n");
 }
 
 static int al3320a_init(struct al3320a_data *data)
 {
+	struct device *dev = regmap_get_device(data->regmap);
 	int ret;
 
-	ret = al3320a_set_pwr_on(data->client);
-
-	if (ret < 0)
-		return ret;
-
-	ret = devm_add_action_or_reset(&data->client->dev,
-				       al3320a_set_pwr_off,
-				       data);
+	ret = al3320a_set_pwr_on(data);
 	if (ret)
 		return ret;
 
-	ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_CONFIG_RANGE,
-					FIELD_PREP(AL3320A_GAIN_MASK,
-						   AL3320A_RANGE_3));
-	if (ret < 0)
+	ret = devm_add_action_or_reset(dev, al3320a_set_pwr_off, data);
+	if (ret)
 		return ret;
 
-	ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_MEAN_TIME,
-					AL3320A_DEFAULT_MEAN_TIME);
-	if (ret < 0)
+	ret = regmap_write(data->regmap, AL3320A_REG_CONFIG_RANGE,
+			   FIELD_PREP(AL3320A_GAIN_MASK, AL3320A_RANGE_3));
+	if (ret)
 		return ret;
 
-	ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_WAIT,
-					AL3320A_DEFAULT_WAIT_TIME);
-	if (ret < 0)
+	ret = regmap_write(data->regmap, AL3320A_REG_MEAN_TIME,
+			   AL3320A_DEFAULT_MEAN_TIME);
+	if (ret)
 		return ret;
 
-	return 0;
+	return regmap_write(data->regmap, AL3320A_REG_WAIT,
+			    AL3320A_DEFAULT_WAIT_TIME);
 }
 
 static int al3320a_read_raw(struct iio_dev *indio_dev,
@@ -131,7 +135,7 @@ static int al3320a_read_raw(struct iio_dev *indio_dev,
 			    int *val2, long mask)
 {
 	struct al3320a_data *data = iio_priv(indio_dev);
-	int ret;
+	int ret, gain, raw;
 
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
@@ -140,21 +144,21 @@ static int al3320a_read_raw(struct iio_dev *indio_dev,
 		 * - low byte of output is stored at AL3320A_REG_DATA_LOW
 		 * - high byte of output is stored at AL3320A_REG_DATA_LOW + 1
 		 */
-		ret = i2c_smbus_read_word_data(data->client,
-					       AL3320A_REG_DATA_LOW);
-		if (ret < 0)
+		ret = regmap_read(data->regmap, AL3320A_REG_DATA_LOW, &raw);
+		if (ret)
 			return ret;
-		*val = ret;
+
+		*val = raw;
+
 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SCALE:
-		ret = i2c_smbus_read_byte_data(data->client,
-					       AL3320A_REG_CONFIG_RANGE);
-		if (ret < 0)
+		ret = regmap_read(data->regmap, AL3320A_REG_CONFIG_RANGE, &gain);
+		if (ret)
 			return ret;
 
-		ret = FIELD_GET(AL3320A_GAIN_MASK, ret);
-		*val = al3320a_scales[ret][0];
-		*val2 = al3320a_scales[ret][1];
+		gain = FIELD_GET(AL3320A_GAIN_MASK, gain);
+		*val = al3320a_scales[gain][0];
+		*val2 = al3320a_scales[gain][1];
 
 		return IIO_VAL_INT_PLUS_MICRO;
 	}
@@ -175,9 +179,8 @@ static int al3320a_write_raw(struct iio_dev *indio_dev,
 			    val2 != al3320a_scales[i][1])
 				continue;
 
-			return i2c_smbus_write_byte_data(data->client,
-					AL3320A_REG_CONFIG_RANGE,
-					FIELD_PREP(AL3320A_GAIN_MASK, i));
+			return regmap_write(data->regmap, AL3320A_REG_CONFIG_RANGE,
+					    FIELD_PREP(AL3320A_GAIN_MASK, i));
 		}
 		break;
 	}
@@ -203,7 +206,11 @@ static int al3320a_probe(struct i2c_client *client)
 
 	data = iio_priv(indio_dev);
 	i2c_set_clientdata(client, indio_dev);
-	data->client = client;
+
+	data->regmap = devm_regmap_init_i2c(client, &al3320a_regmap_config);
+	if (IS_ERR(data->regmap))
+		return dev_err_probe(dev, PTR_ERR(data->regmap),
+				     "cannot allocate regmap\n");
 
 	indio_dev->info = &al3320a_info;
 	indio_dev->name = "al3320a";
@@ -230,7 +237,9 @@ static int al3320a_suspend(struct device *dev)
 
 static int al3320a_resume(struct device *dev)
 {
-	return al3320a_set_pwr_on(to_i2c_client(dev));
+	struct al3320a_data *data = iio_priv(dev_get_drvdata(dev));
+
+	return al3320a_set_pwr_on(data);
 }
 
 static DEFINE_SIMPLE_DEV_PM_OPS(al3320a_pm_ops, al3320a_suspend,