iio: core: Add devm_ APIs for iio_channel_{get,release}

Some of kernel driver uses the IIO framework to get the sensor
value via ADC or IIO HW driver. The client driver get iio channel
by iio_channel_get() and release it by calling iio_channel_release().

Add resource managed version (devm_*) of these APIs so that if client
calls the devm_iio_channel_get() then it need not to release it explicitly,
it can be done by managed device framework when driver get un-binded.

This reduces the code in error path and also need of .remove callback in
some cases.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 27 insertions, 0 deletions

diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
index fad58671c49e..e1e033d6a81f 100644
--- a/include/linux/iio/consumer.h
+++ b/include/linux/iio/consumer.h
@@ -49,6 +49,33 @@ struct iio_channel *iio_channel_get(struct device *dev,
 void iio_channel_release(struct iio_channel *chan);
 
 /**
+ * devm_iio_channel_get() - Resource managed version of iio_channel_get().
+ * @dev:		Pointer to consumer device. Device name must match
+ *			the name of the device as provided in the iio_map
+ *			with which the desired provider to consumer mapping
+ *			was registered.
+ * @consumer_channel:	Unique name to identify the channel on the consumer
+ *			side. This typically describes the channels use within
+ *			the consumer. E.g. 'battery_voltage'
+ *
+ * Returns a pointer to negative errno if it is not able to get the iio channel
+ * otherwise returns valid pointer for iio channel.
+ *
+ * The allocated iio channel is automatically released when the device is
+ * unbound.
+ */
+struct iio_channel *devm_iio_channel_get(struct device *dev,
+					 const char *consumer_channel);
+/**
+ * devm_iio_channel_release() - Resource managed version of
+ *				iio_channel_release().
+ * @dev:		Pointer to consumer device for which resource
+ *			is allocared.
+ * @chan:		The channel to be released.
+ */
+void devm_iio_channel_release(struct device *dev, struct iio_channel *chan);
+
+/**
  * iio_channel_get_all() - get all channels associated with a client
  * @dev:		Pointer to consumer device.
  *