IIO: inkern: API for manipulating channel attributes

Extend the inkern API with functions for reading and writing
attribute of iio channels.
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/iio/inkern.c

@@ -664,8 +664,7 @@ int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
 }
 EXPORT_SYMBOL_GPL(iio_convert_raw_to_processed);
 
-static int iio_read_channel_attribute(struct iio_channel *chan,
-				      int *val, int *val2,
+int iio_read_channel_attribute(struct iio_channel *chan, int *val, int *val2,
 			       enum iio_chan_info_enum attribute)
 {
 	int ret;
@@ -682,6 +681,7 @@ static int iio_read_channel_attribute(struct iio_channel *chan,
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(iio_read_channel_attribute);
 
 int iio_read_channel_offset(struct iio_channel *chan, int *val, int *val2)
 {
@@ -850,7 +850,8 @@ static int iio_channel_write(struct iio_channel *chan, int val, int val2,
 						chan->channel, val, val2, info);
 }
 
-int iio_write_channel_raw(struct iio_channel *chan, int val)
+int iio_write_channel_attribute(struct iio_channel *chan, int val, int val2,
+				enum iio_chan_info_enum attribute)
 {
 	int ret;
 
@@ -860,12 +861,18 @@ int iio_write_channel_raw(struct iio_channel *chan, int val)
 		goto err_unlock;
 	}
 
-	ret = iio_channel_write(chan, val, 0, IIO_CHAN_INFO_RAW);
+	ret = iio_channel_write(chan, val, val2, attribute);
 err_unlock:
 	mutex_unlock(&chan->indio_dev->info_exist_lock);
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(iio_write_channel_attribute);
+
+int iio_write_channel_raw(struct iio_channel *chan, int val)
+{
+	return iio_write_channel_attribute(chan, val, 0, IIO_CHAN_INFO_RAW);
+}
 EXPORT_SYMBOL_GPL(iio_write_channel_raw);
 
 unsigned int iio_get_channel_ext_info_count(struct iio_channel *chan)

include/linux/iio/consumer.h

@@ -215,6 +215,32 @@ int iio_read_channel_average_raw(struct iio_channel *chan, int *val);
  */
 int iio_read_channel_processed(struct iio_channel *chan, int *val);
 
+/**
+ * iio_write_channel_attribute() - Write values to the device attribute.
+ * @chan:	The channel being queried.
+ * @val:	Value being written.
+ * @val2:	Value being written.val2 use depends on attribute type.
+ * @attribute:	info attribute to be read.
+ *
+ * Returns an error code or 0.
+ */
+int iio_write_channel_attribute(struct iio_channel *chan, int val,
+				int val2, enum iio_chan_info_enum attribute);
+
+/**
+ * iio_read_channel_attribute() - Read values from the device attribute.
+ * @chan:	The channel being queried.
+ * @val:	Value being written.
+ * @val2:	Value being written.Val2 use depends on attribute type.
+ * @attribute:	info attribute to be written.
+ *
+ * Returns an error code if failed. Else returns a description of what is in val
+ * and val2, such as IIO_VAL_INT_PLUS_MICRO telling us we have a value of val
+ * + val2/1e6
+ */
+int iio_read_channel_attribute(struct iio_channel *chan, int *val,
+			       int *val2, enum iio_chan_info_enum attribute);
+
 /**
  * iio_write_channel_raw() - write to a given channel
  * @chan:		The channel being queried.

include/linux/iio/iio.h

@@ -20,34 +20,6 @@
  * Currently assumes nano seconds.
  */
 
-enum iio_chan_info_enum {
-	IIO_CHAN_INFO_RAW = 0,
-	IIO_CHAN_INFO_PROCESSED,
-	IIO_CHAN_INFO_SCALE,
-	IIO_CHAN_INFO_OFFSET,
-	IIO_CHAN_INFO_CALIBSCALE,
-	IIO_CHAN_INFO_CALIBBIAS,
-	IIO_CHAN_INFO_PEAK,
-	IIO_CHAN_INFO_PEAK_SCALE,
-	IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW,
-	IIO_CHAN_INFO_AVERAGE_RAW,
-	IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY,
-	IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY,
-	IIO_CHAN_INFO_SAMP_FREQ,
-	IIO_CHAN_INFO_FREQUENCY,
-	IIO_CHAN_INFO_PHASE,
-	IIO_CHAN_INFO_HARDWAREGAIN,
-	IIO_CHAN_INFO_HYSTERESIS,
-	IIO_CHAN_INFO_INT_TIME,
-	IIO_CHAN_INFO_ENABLE,
-	IIO_CHAN_INFO_CALIBHEIGHT,
-	IIO_CHAN_INFO_CALIBWEIGHT,
-	IIO_CHAN_INFO_DEBOUNCE_COUNT,
-	IIO_CHAN_INFO_DEBOUNCE_TIME,
-	IIO_CHAN_INFO_CALIBEMISSIVITY,
-	IIO_CHAN_INFO_OVERSAMPLING_RATIO,
-};
-
 enum iio_shared_by {
 	IIO_SEPARATE,
 	IIO_SHARED_BY_TYPE,

include/linux/iio/types.h

@@ -34,4 +34,32 @@ enum iio_available_type {
 	IIO_AVAIL_RANGE,
 };
 
+enum iio_chan_info_enum {
+	IIO_CHAN_INFO_RAW = 0,
+	IIO_CHAN_INFO_PROCESSED,
+	IIO_CHAN_INFO_SCALE,
+	IIO_CHAN_INFO_OFFSET,
+	IIO_CHAN_INFO_CALIBSCALE,
+	IIO_CHAN_INFO_CALIBBIAS,
+	IIO_CHAN_INFO_PEAK,
+	IIO_CHAN_INFO_PEAK_SCALE,
+	IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW,
+	IIO_CHAN_INFO_AVERAGE_RAW,
+	IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY,
+	IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY,
+	IIO_CHAN_INFO_SAMP_FREQ,
+	IIO_CHAN_INFO_FREQUENCY,
+	IIO_CHAN_INFO_PHASE,
+	IIO_CHAN_INFO_HARDWAREGAIN,
+	IIO_CHAN_INFO_HYSTERESIS,
+	IIO_CHAN_INFO_INT_TIME,
+	IIO_CHAN_INFO_ENABLE,
+	IIO_CHAN_INFO_CALIBHEIGHT,
+	IIO_CHAN_INFO_CALIBWEIGHT,
+	IIO_CHAN_INFO_DEBOUNCE_COUNT,
+	IIO_CHAN_INFO_DEBOUNCE_TIME,
+	IIO_CHAN_INFO_CALIBEMISSIVITY,
+	IIO_CHAN_INFO_OVERSAMPLING_RATIO,
+};
+
 #endif /* _IIO_TYPES_H_ */