[PATCH v4 5/7] iio: potentiometer: Add device specific read_raw function

[Jagath Jog J <jagathjog1996@gmail.com>]

Added function pointer in the device specific structure to
call the appropriate device read_raw function, so that the
other type of devices with different read method can be
handled.

Signed-off-by: Jagath Jog J <jagathjog1996@gmail.com>
---
 drivers/iio/potentiometer/ds1803.c | 34 ++++++++++++++++++++++--------
 1 file changed, 25 insertions(+), 9 deletions(-)

diff --git a/drivers/iio/potentiometer/ds1803.c b/drivers/iio/potentiometer/ds1803.c
index 3b86a4106277..1d6175dc4319 100644
--- a/drivers/iio/potentiometer/ds1803.c
+++ b/drivers/iio/potentiometer/ds1803.c
@@ -31,6 +31,8 @@ struct ds1803_cfg {
 	int kohms;
 	const struct iio_chan_spec *channels;
 	u8 num_channels;
+	int (*read)(struct iio_dev *indio_dev,
+		    struct iio_chan_spec const *chan, int *val);
 };
 
 struct ds1803_data {
@@ -54,16 +56,35 @@ static const struct iio_chan_spec ds1803_channels[] = {
 	DS1803_CHANNEL(1, DS1803_WIPER_1),
 };
 
+static int ds1803_read(struct iio_dev *indio_dev,
+		       struct iio_chan_spec const *chan,
+		       int *val)
+{
+	struct ds1803_data *data = iio_priv(indio_dev);
+	int ret;
+	u8 result[ARRAY_SIZE(ds1803_channels)];
+
+	ret = i2c_master_recv(data->client, result, indio_dev->num_channels);
+	if (ret < 0)
+		return ret;
+
+	*val = result[chan->channel];
+	return ret;
+}
+
 static const struct ds1803_cfg ds1803_cfg[] = {
 	[DS1803_010] = { .wipers = 2, .avail = { 0, 1, 255 }, .kohms =  10,
 			 .channels = ds1803_channels,
-			 .num_channels = ARRAY_SIZE(ds1803_channels) },
+			 .num_channels = ARRAY_SIZE(ds1803_channels),
+			 .read = ds1803_read },
 	[DS1803_050] = { .wipers = 2, .avail = { 0, 1, 255 }, .kohms =  50,
 			 .channels = ds1803_channels,
-			 .num_channels = ARRAY_SIZE(ds1803_channels) },
+			 .num_channels = ARRAY_SIZE(ds1803_channels),
+			 .read = ds1803_read },
 	[DS1803_100] = { .wipers = 2, .avail = { 0, 1, 255 }, .kohms = 100,
 			 .channels = ds1803_channels,
-			 .num_channels = ARRAY_SIZE(ds1803_channels) },
+			 .num_channels = ARRAY_SIZE(ds1803_channels),
+			 .read = ds1803_read },
 };
 
 static int ds1803_read_raw(struct iio_dev *indio_dev,
@@ -71,20 +92,15 @@ static int ds1803_read_raw(struct iio_dev *indio_dev,
 			   int *val, int *val2, long mask)
 {
 	struct ds1803_data *data = iio_priv(indio_dev);
-	int pot = chan->channel;
 	int ret;
-	u8 result[ARRAY_SIZE(ds1803_channels)];
 
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
-		ret = i2c_master_recv(data->client, result,
-				      indio_dev->num_channels);
+		ret = data->cfg->read(indio_dev, chan, val);
 		if (ret < 0)
 			return ret;
 
-		*val = result[pot];
 		return IIO_VAL_INT;
-
 	case IIO_CHAN_INFO_SCALE:
 		*val = 1000 * data->cfg->kohms;
 		*val2 = data->cfg->avail[2]; /* Max wiper position */
-- 
2.17.1