1 files changed, 45 insertions, 16 deletions

diff --git a/drivers/iio/potentiometer/ds1803.c b/drivers/iio/potentiometer/ds1803.c
index 3c542a50ece6..2861c4d39328 100644
--- a/drivers/iio/potentiometer/ds1803.c
+++ b/drivers/iio/potentiometer/ds1803.c
@@ -16,7 +16,6 @@
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>
 
-#define DS1803_MAX_POS		255
 #define DS1803_WRITE(chan)	(0xa8 | ((chan) + 1))
 
 enum ds1803_type {
@@ -26,27 +25,23 @@ enum ds1803_type {
 };
 
 struct ds1803_cfg {
+	int avail[3];
 	int kohms;
 };
 
-static const struct ds1803_cfg ds1803_cfg[] = {
-	[DS1803_010] = { .kohms =  10, },
-	[DS1803_050] = { .kohms =  50, },
-	[DS1803_100] = { .kohms = 100, },
-};
-
 struct ds1803_data {
 	struct i2c_client *client;
 	const struct ds1803_cfg *cfg;
 };
 
-#define DS1803_CHANNEL(ch) {					\
-	.type = IIO_RESISTANCE,					\
-	.indexed = 1,						\
-	.output = 1,						\
-	.channel = (ch),					\
-	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
-	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+#define DS1803_CHANNEL(ch) {						\
+	.type = IIO_RESISTANCE,						\
+	.indexed = 1,							\
+	.output = 1,							\
+	.channel = (ch),						\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),		\
+	.info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_RAW),   \
 }
 
 static const struct iio_chan_spec ds1803_channels[] = {
@@ -54,6 +49,21 @@ static const struct iio_chan_spec ds1803_channels[] = {
 	DS1803_CHANNEL(1),
 };
 
+static const struct ds1803_cfg ds1803_cfg[] = {
+	[DS1803_010] = {
+		.avail = { 0, 1, 255 },
+		.kohms =  10,
+	},
+	[DS1803_050] = {
+		.avail = { 0, 1, 255 },
+		.kohms =  50,
+	},
+	[DS1803_100] = {
+		.avail = { 0, 1, 255 },
+		.kohms = 100,
+	},
+};
+
 static int ds1803_read_raw(struct iio_dev *indio_dev,
 			   struct iio_chan_spec const *chan,
 			   int *val, int *val2, long mask)
@@ -75,7 +85,7 @@ static int ds1803_read_raw(struct iio_dev *indio_dev,
 
 	case IIO_CHAN_INFO_SCALE:
 		*val = 1000 * data->cfg->kohms;
-		*val2 = DS1803_MAX_POS;
+		*val2 = data->cfg->avail[2]; /* Max wiper position */
 		return IIO_VAL_FRACTIONAL;
 	}
 
@@ -88,13 +98,14 @@ static int ds1803_write_raw(struct iio_dev *indio_dev,
 {
 	struct ds1803_data *data = iio_priv(indio_dev);
 	int pot = chan->channel;
+	int max_pos = data->cfg->avail[2];
 
 	if (val2 != 0)
 		return -EINVAL;
 
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
-		if (val > DS1803_MAX_POS || val < 0)
+		if (val > max_pos || val < 0)
 			return -EINVAL;
 		break;
 	default:
@@ -104,9 +115,27 @@ static int ds1803_write_raw(struct iio_dev *indio_dev,
 	return i2c_smbus_write_byte_data(data->client, DS1803_WRITE(pot), val);
 }
 
+static int ds1803_read_avail(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     const int **vals, int *type,
+			     int *length, long mask)
+{
+	struct ds1803_data *data = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		*vals = data->cfg->avail;
+		*length = ARRAY_SIZE(data->cfg->avail);
+		*type = IIO_VAL_INT;
+		return IIO_AVAIL_RANGE;
+	}
+	return -EINVAL;
+}
+
 static const struct iio_info ds1803_info = {
 	.read_raw = ds1803_read_raw,
 	.write_raw = ds1803_write_raw,
+	.read_avail = ds1803_read_avail,
 };
 
 static int ds1803_probe(struct i2c_client *client, const struct i2c_device_id *id)