[PATCH v2 3/4] iio: light: opt4001: refactor driver to prepare to support more devices

[Jesper X Nilsson <jesper.x.nilsson@axis.com>]

Prepare opt4001 driver to be able to support OPT4041. Extend struct
opt4001_chip_info with fields channels and device_id because OPT4041 has
two channels and another device id.

Datasheet: https://www.ti.com/lit/gpn/opt4041
Signed-off-by: Jesper X Nilsson <jesper.x.nilsson@axis.com>
---
 drivers/iio/light/opt4001.c | 85 +++++++++++++++++++++++++++++----------------
 1 file changed, 55 insertions(+), 30 deletions(-)

diff --git a/drivers/iio/light/opt4001.c b/drivers/iio/light/opt4001.c
index dcde10914a1e..dc2eac8ad4af 100644
--- a/drivers/iio/light/opt4001.c
+++ b/drivers/iio/light/opt4001.c
@@ -77,6 +77,9 @@
 struct opt4001_chip_info {
 	struct s32_fract ratio;
 	const char *name;
+	const struct iio_chan_spec *channels;
+	int num_channels;
+	u16 device_id;
 };
 
 struct opt4001_chip {
@@ -86,14 +89,30 @@ struct opt4001_chip {
 	const struct opt4001_chip_info *chip_info;
 };
 
+static const struct iio_chan_spec opt4001_channels[] = {
+	{
+		.type = IIO_LIGHT,
+		.address = OPT4001_LIGHT1_MSB,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+		.info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
+	},
+};
+
 static const struct opt4001_chip_info opt4001_sot_5x3_info = {
 	.ratio = { .numerator = 4375, .denominator = 10000000 },
-	.name = "opt4001-sot-5x3"
+	.name = "opt4001-sot-5x3",
+	.channels = opt4001_channels,
+	.num_channels = ARRAY_SIZE(opt4001_channels),
+	.device_id = OPT4001_DEVICE_ID_VAL,
 };
 
 static const struct opt4001_chip_info opt4001_picostar_info = {
 	.ratio = { .numerator = 3125, .denominator = 10000000 },
-	.name = "opt4001-picostar"
+	.name = "opt4001-picostar",
+	.channels = opt4001_channels,
+	.num_channels = ARRAY_SIZE(opt4001_channels),
+	.device_id = OPT4001_DEVICE_ID_VAL,
 };
 
 static const int opt4001_int_time_available[][2] = {
@@ -156,30 +175,28 @@ static u8 opt4001_calculate_crc(u8 exp, u32 mantissa, u8 count)
 	return crc;
 }
 
-static int opt4001_read_lux_value(struct iio_dev *indio_dev,
-				  int *val, int *val2)
+static int opt4001_read_raw_value(struct opt4001_chip *chip, unsigned int reg,
+				  u64 *raw_value)
 {
-	struct opt4001_chip *chip = iio_priv(indio_dev);
 	struct device *dev = &chip->client->dev;
 	unsigned int light1;
 	unsigned int light2;
+	u32 mantissa;
+	u8 calc_crc;
+	u8 count;
 	u16 msb;
 	u16 lsb;
+	int ret;
 	u8 exp;
-	u8 count;
 	u8 crc;
-	u8 calc_crc;
-	u64 lux_raw;
-	u32 rem;
-	int ret;
 
-	ret = regmap_read(chip->regmap, OPT4001_LIGHT1_MSB, &light1);
+	ret = regmap_read(chip->regmap, reg, &light1);
 	if (ret < 0) {
 		dev_err(dev, "Failed to read data bytes");
 		return ret;
 	}
 
-	ret = regmap_read(chip->regmap, OPT4001_LIGHT1_LSB, &light2);
+	ret = regmap_read(chip->regmap, reg + 1, &light2);
 	if (ret < 0) {
 		dev_err(dev, "Failed to read data bytes");
 		return ret;
@@ -190,12 +207,27 @@ static int opt4001_read_lux_value(struct iio_dev *indio_dev,
 	crc = FIELD_GET(OPT4001_CRC_MASK, light2);
 	msb = FIELD_GET(OPT4001_MSB_MASK, light1);
 	lsb = FIELD_GET(OPT4001_LSB_MASK, light2);
-	lux_raw = (msb << 8) + lsb;
-	calc_crc = opt4001_calculate_crc(exp, lux_raw, count);
+	mantissa = (msb << 8) + lsb;
+	calc_crc = opt4001_calculate_crc(exp, mantissa, count);
 	if (calc_crc != crc)
 		return -EIO;
 
-	lux_raw = lux_raw << exp;
+	*raw_value = (u64)mantissa << exp;
+
+	return 0;
+}
+
+static int opt4001_read_lux_value(struct opt4001_chip *chip, unsigned int reg,
+				  int *val, int *val2)
+{
+	u64 lux_raw;
+	u32 rem;
+	int ret;
+
+	ret = opt4001_read_raw_value(chip, reg, &lux_raw);
+	if (ret)
+		return ret;
+
 	lux_raw = lux_raw * chip->chip_info->ratio.numerator;
 	*val = div_u64_rem(lux_raw, chip->chip_info->ratio.denominator, &rem);
 	*val2 = rem * 100;
@@ -230,15 +262,6 @@ static void opt4001_chip_off_action(void *data)
 		dev_err(&chip->client->dev, "Failed to power down\n");
 }
 
-static const struct iio_chan_spec opt4001_channels[] = {
-	{
-		.type = IIO_LIGHT,
-		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
-		.info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME),
-		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME)
-	},
-};
-
 static int opt4001_read_raw(struct iio_dev *indio_dev,
 			    struct iio_chan_spec const *chan,
 			    int *val, int *val2, long mask)
@@ -247,7 +270,7 @@ static int opt4001_read_raw(struct iio_dev *indio_dev,
 
 	switch (mask) {
 	case IIO_CHAN_INFO_PROCESSED:
-		return opt4001_read_lux_value(indio_dev, val, val2);
+		return opt4001_read_lux_value(chip, chan->address, val, val2);
 	case IIO_CHAN_INFO_INT_TIME:
 		*val = 0;
 		*val2 = opt4001_int_time_reg[chip->int_time][0];
@@ -385,19 +408,21 @@ static int opt4001_probe(struct i2c_client *client)
 		return dev_err_probe(&client->dev, ret,
 				     "failed to reinit regmap cache\n");
 
+	chip->chip_info = i2c_get_match_data(client);
+	if (!chip->chip_info)
+		return -ENODATA;
+
 	ret = regmap_read(chip->regmap, OPT4001_DEVICE_ID, &dev_id);
 	if (ret < 0)
 		return dev_err_probe(&client->dev, ret,
 			"Failed to read the device ID register\n");
 
 	dev_id = FIELD_GET(OPT4001_DEVICE_ID_MASK, dev_id);
-	if (dev_id != OPT4001_DEVICE_ID_VAL)
+	if (dev_id != chip->chip_info->device_id)
 		dev_warn(&client->dev, "Device ID: %#04x unknown\n", dev_id);
 
-	chip->chip_info = i2c_get_match_data(client);
-
-	indio_dev->channels = opt4001_channels;
-	indio_dev->num_channels = ARRAY_SIZE(opt4001_channels);
+	indio_dev->channels = chip->chip_info->channels;
+	indio_dev->num_channels = chip->chip_info->num_channels;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->name = chip->chip_info->name;
 

-- 
2.43.0