[PATCH v1] staging: iio: ad7816: add iio interface

[JuenKit Yip <JuenKit_Yip@xxxxxxxxxxx>]

add iio interface for 4 channels, replacing the previous sysfs
interface

Signed-off-by: JuenKit Yip <JuenKit_Yip@xxxxxxxxxxx>
---
 drivers/staging/iio/adc/ad7816.c | 122 +++++++++++++++----------------
 1 file changed, 59 insertions(+), 63 deletions(-)

diff --git a/drivers/staging/iio/adc/ad7816.c b/drivers/staging/iio/adc/ad7816.c
index 6c14d7bcdd67..8af117b6ae11 100644
--- a/drivers/staging/iio/adc/ad7816.c
+++ b/drivers/staging/iio/adc/ad7816.c
@@ -162,64 +162,17 @@ static ssize_t ad7816_show_available_modes(struct device *dev,
 static IIO_DEVICE_ATTR(available_modes, 0444, ad7816_show_available_modes,
 			NULL, 0);
 
-static ssize_t ad7816_show_channel(struct device *dev,
-				   struct device_attribute *attr,
-				   char *buf)
+static int ad7816_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val,
+			   int *val2,
+			   long m)
 {
-	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-	struct ad7816_chip_info *chip = iio_priv(indio_dev);
-
-	return sprintf(buf, "%d\n", chip->channel_id);
-}
-
-static ssize_t ad7816_store_channel(struct device *dev,
-				    struct device_attribute *attr,
-				    const char *buf,
-				    size_t len)
-{
-	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-	struct ad7816_chip_info *chip = iio_priv(indio_dev);
-	unsigned long data;
-	int ret;
-
-	ret = kstrtoul(buf, 10, &data);
-	if (ret)
-		return ret;
-
-	if (data > AD7816_CS_MAX && data != AD7816_CS_MASK) {
-		dev_err(&chip->spi_dev->dev, "Invalid channel id %lu for %s.\n",
-			data, indio_dev->name);
-		return -EINVAL;
-	} else if (strcmp(indio_dev->name, "ad7818") == 0 && data > 1) {
-		dev_err(&chip->spi_dev->dev,
-			"Invalid channel id %lu for ad7818.\n", data);
-		return -EINVAL;
-	} else if (strcmp(indio_dev->name, "ad7816") == 0 && data > 0) {
-		dev_err(&chip->spi_dev->dev,
-			"Invalid channel id %lu for ad7816.\n", data);
-		return -EINVAL;
-	}
-
-	chip->channel_id = data;
-
-	return len;
-}
-
-static IIO_DEVICE_ATTR(channel, 0644,
-		ad7816_show_channel,
-		ad7816_store_channel,
-		0);
-
-static ssize_t ad7816_show_value(struct device *dev,
-				 struct device_attribute *attr,
-				 char *buf)
-{
-	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct ad7816_chip_info *chip = iio_priv(indio_dev);
 	u16 data;
-	s8 value;
 	int ret;
 
+	chip->channel_id = (u8)chan->channel;
 	ret = ad7816_spi_read(chip, &data);
 	if (ret)
 		return -EIO;
@@ -227,22 +180,21 @@ static ssize_t ad7816_show_value(struct device *dev,
 	data >>= AD7816_VALUE_OFFSET;
 
 	if (chip->channel_id == 0) {
-		value = (s8)((data >> AD7816_TEMP_FLOAT_OFFSET) - 103);
-		data &= AD7816_TEMP_FLOAT_MASK;
-		if (value < 0)
-			data = BIT(AD7816_TEMP_FLOAT_OFFSET) - data;
-		return sprintf(buf, "%d.%.2d\n", value, data * 25);
+		*val = (s8)((data >> AD7816_TEMP_FLOAT_OFFSET) - 103);
+		*val2 = (data & AD7816_TEMP_FLOAT_MASK) * 25;
+		if (*val < 0)
+			*val2 = BIT(AD7816_TEMP_FLOAT_OFFSET) - *val2;
+		return IIO_VAL_INT_PLUS_MICRO;
 	}
-	return sprintf(buf, "%u\n", data);
-}
 
-static IIO_DEVICE_ATTR(value, 0444, ad7816_show_value, NULL, 0);
+	*val = data;
+
+	return IIO_VAL_INT;
+}
 
 static struct attribute *ad7816_attributes[] = {
 	&iio_dev_attr_available_modes.dev_attr.attr,
 	&iio_dev_attr_mode.dev_attr.attr,
-	&iio_dev_attr_channel.dev_attr.attr,
-	&iio_dev_attr_value.dev_attr.attr,
 	NULL,
 };
 
@@ -341,10 +293,47 @@ static const struct attribute_group ad7816_event_attribute_group = {
 };
 
 static const struct iio_info ad7816_info = {
+	.read_raw = ad7816_read_raw,
 	.attrs = &ad7816_attribute_group,
 	.event_attrs = &ad7816_event_attribute_group,
 };
 
+static const struct iio_chan_spec ad7816_channels[] = {
+	{
+		.type = IIO_TEMP,
+		.indexed = 1,
+		.channel = 0,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+	},
+};
+
+static const struct iio_chan_spec ad7817_channels[] = {
+	{
+		.type = IIO_TEMP,
+		.indexed = 1,
+		.channel = 0,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+	},
+	{
+		.type = IIO_VOLTAGE,
+		.indexed = 1,
+		.channel = 1,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+	},
+	{
+		.type = IIO_VOLTAGE,
+		.indexed = 1,
+		.channel = 2,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+	},
+	{
+		.type = IIO_VOLTAGE,
+		.indexed = 1,
+		.channel = 3,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+	},
+};
+
 /*
  * device probe and remove
  */
@@ -367,6 +356,13 @@ static int ad7816_probe(struct spi_device *spi_dev)
 		chip->oti_data[i] = 203;
 
 	chip->id = spi_get_device_id(spi_dev)->driver_data;
+	if (chip->id == ID_AD7816) {
+		indio_dev->channels = ad7816_channels;
+		indio_dev->num_channels = ARRAY_SIZE(ad7816_channels);
+	} else {
+		indio_dev->channels = ad7817_channels;
+		indio_dev->num_channels = ARRAY_SIZE(ad7817_channels);
+	}
 	chip->rdwr_pin = devm_gpiod_get(&spi_dev->dev, "rdwr", GPIOD_OUT_HIGH);
 	if (IS_ERR(chip->rdwr_pin)) {
 		ret = PTR_ERR(chip->rdwr_pin);
-- 
2.39.2