[PATCH 1/2] iio: core: Add devm_ API for iio_channel_get_sys

[Chris Morgan <macroalpha82@gmail.com>]

From: Chris Morgan <macromorgan@hotmail.com>

Some kernel drivers use the IIO framework to get voltage and current
data via ADC or IIO HW driver. This is complicated by the fact that
the consumer of this data is not a child of the IIO HW which current
helpers depend on being the case.

Add resource managed version (devm_*) of the APIs so that the client
driver can call by name alone for the iio channel.

Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
---
 drivers/iio/inkern.c         | 18 ++++++++++++++++++
 include/linux/iio/consumer.h | 20 ++++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index 136b225b6bc8..5df9e272743f 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -418,6 +418,24 @@ struct iio_channel *devm_iio_channel_get(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(devm_iio_channel_get);
 
+struct iio_channel *devm_iio_channel_get_sys(struct device *dev,
+					     const char *channel_name)
+{
+	struct iio_channel *channel;
+	int ret;
+
+	channel = iio_channel_get_sys(NULL, channel_name);
+	if (IS_ERR(channel))
+		return channel;
+
+	ret = devm_add_action_or_reset(dev, devm_iio_channel_free, channel);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return channel;
+}
+EXPORT_SYMBOL_GPL(devm_iio_channel_get_sys);
+
 struct iio_channel *devm_fwnode_iio_channel_get_by_name(struct device *dev,
 							struct fwnode_handle *fwnode,
 							const char *channel_name)
diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
index 333d1d8ccb37..bde075b5fb65 100644
--- a/include/linux/iio/consumer.h
+++ b/include/linux/iio/consumer.h
@@ -64,6 +64,26 @@ void iio_channel_release(struct iio_channel *chan);
  */
 struct iio_channel *devm_iio_channel_get(struct device *dev,
 					 const char *consumer_channel);
+
+/**
+ * devm_iio_channel_get_sys() - Resource managed version of
+				iio_channel_get_sys().
+ * @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_sys(struct device *dev,
+					     const char *consumer_channel);
 /**
  * iio_channel_get_all() - get all channels associated with a client
  * @dev:		Pointer to consumer device.
-- 
2.43.0