[PATCH 2/3] staging:iio:dac:max517: Convert to channel spec

[Lars-Peter Clausen <lars@metafoo.de>]

Convert the max517 driver to channel spec. As part of the conversion the
"out_voltage_1&2_raw" property, which updates both channel 1 and 2
simultaneously with the same value, is lost, since this is not really covered by
the IIO spec.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Roland Stigge <stigge@antcom.de>
---
 drivers/staging/iio/dac/max517.c |  145 ++++++++++++++------------------------
 1 file changed, 53 insertions(+), 92 deletions(-)

diff --git a/drivers/staging/iio/dac/max517.c b/drivers/staging/iio/dac/max517.c
index 65d6349..ec8c88c 100644
--- a/drivers/staging/iio/dac/max517.c
+++ b/drivers/staging/iio/dac/max517.c
@@ -27,7 +27,6 @@
 
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
-#include "dac.h"
 
 #include "max517.h"
 
@@ -55,22 +54,14 @@ struct max517_data {
  *          bit 1: channel 2
  * (this way, it's possible to set both channels at once)
  */
-static ssize_t max517_set_value(struct device *dev,
-				 struct device_attribute *attr,
-				 const char *buf, size_t count, int channel)
+static ssize_t max517_set_value(struct iio_dev *indio_dev,
+	long val, int channel)
 {
-	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct max517_data *data = iio_priv(indio_dev);
 	struct i2c_client *client = data->client;
 	u8 outbuf[4]; /* 1x or 2x command + value */
 	int outbuf_size = 0;
 	int res;
-	long val;
-
-	res = strict_strtol(buf, 10, &val);
-
-	if (res)
-		return res;
 
 	if (val < 0 || val > 255)
 		return -EINVAL;
@@ -95,89 +86,46 @@ static ssize_t max517_set_value(struct device *dev,
 	if (res < 0)
 		return res;
 
-	return count;
-}
-
-static ssize_t max517_set_value_1(struct device *dev,
-				 struct device_attribute *attr,
-				 const char *buf, size_t count)
-{
-	return max517_set_value(dev, attr, buf, count, 1);
-}
-static IIO_DEV_ATTR_OUT_RAW(1, max517_set_value_1, 0);
-
-static ssize_t max517_set_value_2(struct device *dev,
-				 struct device_attribute *attr,
-				 const char *buf, size_t count)
-{
-	return max517_set_value(dev, attr, buf, count, 2);
-}
-static IIO_DEV_ATTR_OUT_RAW(2, max517_set_value_2, 1);
-
-static ssize_t max517_set_value_both(struct device *dev,
-				 struct device_attribute *attr,
-				 const char *buf, size_t count)
-{
-	return max517_set_value(dev, attr, buf, count, 3);
+	return 0;
 }
-static IIO_DEVICE_ATTR_NAMED(out_voltage1and2_raw,
-			     out_voltage1&2_raw, S_IWUSR, NULL,
-			     max517_set_value_both, -1);
 
-static ssize_t max517_show_scale(struct device *dev,
-				struct device_attribute *attr,
-				char *buf, int channel)
+static int max517_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_get_drvdata(dev);
 	struct max517_data *data = iio_priv(indio_dev);
-	/* Corresponds to Vref / 2^(bits) */
-	unsigned int scale_uv = (data->vref_mv[channel - 1] * 1000) >> 8;
-
-	return sprintf(buf, "%d.%03d\n", scale_uv / 1000, scale_uv % 1000);
+	int scale_uv;
+
+	switch (m) {
+	case IIO_CHAN_INFO_SCALE:
+		/* Corresponds to Vref / 2^(bits) */
+		scale_uv = (data->vref_mv[chan->channel] * 1000) >> 8;
+		*val =  scale_uv / 1000000;
+		*val2 = scale_uv % 1000000;
+		return IIO_VAL_INT_PLUS_MICRO;
+	default:
+		break;
+	}
+	return -EINVAL;
 }
 
-static ssize_t max517_show_scale1(struct device *dev,
-				struct device_attribute *attr,
-				char *buf)
+static int max517_write_raw(struct iio_dev *indio_dev,
+	struct iio_chan_spec const *chan, int val, int val2, long mask)
 {
-	return max517_show_scale(dev, attr, buf, 1);
-}
-static IIO_DEVICE_ATTR(out_voltage1_scale, S_IRUGO,
-		       max517_show_scale1, NULL, 0);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = max517_set_value(indio_dev, val, chan->channel);
+		break;
+	default:
+		ret = -EINVAL;
+	}
 
-static ssize_t max517_show_scale2(struct device *dev,
-				struct device_attribute *attr,
-				char *buf)
-{
-	return max517_show_scale(dev, attr, buf, 2);
+	return ret;
 }
-static IIO_DEVICE_ATTR(out_voltage2_scale, S_IRUGO,
-		       max517_show_scale2, NULL, 0);
-
-/* On MAX517 variant, we have one output */
-static struct attribute *max517_attributes[] = {
-	&iio_dev_attr_out_voltage1_raw.dev_attr.attr,
-	&iio_dev_attr_out_voltage1_scale.dev_attr.attr,
-	NULL
-};
-
-static struct attribute_group max517_attribute_group = {
-	.attrs = max517_attributes,
-};
-
-/* On MAX518 and MAX519 variant, we have two outputs */
-static struct attribute *max518_attributes[] = {
-	&iio_dev_attr_out_voltage1_raw.dev_attr.attr,
-	&iio_dev_attr_out_voltage1_scale.dev_attr.attr,
-	&iio_dev_attr_out_voltage2_raw.dev_attr.attr,
-	&iio_dev_attr_out_voltage2_scale.dev_attr.attr,
-	&iio_dev_attr_out_voltage1and2_raw.dev_attr.attr,
-	NULL
-};
-
-static struct attribute_group max518_attribute_group = {
-	.attrs = max518_attributes,
-};
 
 #ifdef CONFIG_PM_SLEEP
 static int max517_suspend(struct device *dev)
@@ -201,13 +149,24 @@ static SIMPLE_DEV_PM_OPS(max517_pm_ops, max517_suspend, max517_resume);
 #endif
 
 static const struct iio_info max517_info = {
-	.attrs = &max517_attribute_group,
+	.read_raw = max517_read_raw,
+	.write_raw = max517_write_raw,
 	.driver_module = THIS_MODULE,
 };
 
-static const struct iio_info max518_info = {
-	.attrs = &max518_attribute_group,
-	.driver_module = THIS_MODULE,
+#define MAX517_CHANNEL(chan) {				\
+	.type = IIO_VOLTAGE,					\
+	.indexed = 1,						\
+	.output = 1,						\
+	.channel = (chan),					\
+	.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |		\
+	IIO_CHAN_INFO_SCALE_SEPARATE_BIT,			\
+	.scan_type = IIO_ST('u', 8, 8, 0),	\
+}
+
+static const struct iio_chan_spec max517_channels[] = {
+	MAX517_CHANNEL(0),
+	MAX517_CHANNEL(1)
 };
 
 static int max517_probe(struct i2c_client *client,
@@ -230,12 +189,14 @@ static int max517_probe(struct i2c_client *client,
 	/* establish that the iio_dev is a child of the i2c device */
 	indio_dev->dev.parent = &client->dev;
 
-	/* reduced attribute set for MAX517 */
+	/* reduced channel set for MAX517 */
 	if (id->driver_data == ID_MAX517)
-		indio_dev->info = &max517_info;
+		indio_dev->num_channels = 1;
 	else
-		indio_dev->info = &max518_info;
+		indio_dev->num_channels = 2;
+	indio_dev->channels = max517_channels;
 	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &max517_info;
 
 	/*
 	 * Reference voltage on MAX518 and default is 5V, else take vref_mv
-- 
1.7.10