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Commit 8bf872d8 authored by Laxman Dewangan's avatar Laxman Dewangan Committed by Jonathan Cameron
Browse files

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: default avatarLaxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 5f991a92

drivers/iio/inkern.c

+48 −0
Original line number Diff line number Diff line
@@ -356,6 +356,54 @@ void iio_channel_release(struct iio_channel *channel) 
}

EXPORT_SYMBOL_GPL(iio_channel_release);



static void devm_iio_channel_free(struct device *dev, void *res)

{

	struct iio_channel *channel = *(struct iio_channel **)res;



	iio_channel_release(channel);

}



static int devm_iio_channel_match(struct device *dev, void *res, void *data)

{

	struct iio_channel **r = res;



	if (!r || !*r) {

		WARN_ON(!r || !*r);

		return 0;

	}



	return *r == data;

}



struct iio_channel *devm_iio_channel_get(struct device *dev,

					 const char *channel_name)

{

	struct iio_channel **ptr, *channel;



	ptr = devres_alloc(devm_iio_channel_free, sizeof(*ptr), GFP_KERNEL);

	if (!ptr)

		return ERR_PTR(-ENOMEM);



	channel = iio_channel_get(dev, channel_name);

	if (IS_ERR(channel)) {

		devres_free(ptr);

		return channel;

	}



	*ptr = channel;

	devres_add(dev, ptr);



	return channel;

}

EXPORT_SYMBOL_GPL(devm_iio_channel_get);



void devm_iio_channel_release(struct device *dev, struct iio_channel *channel)

{

	WARN_ON(devres_release(dev, devm_iio_channel_free,

			       devm_iio_channel_match, channel));

}

EXPORT_SYMBOL_GPL(devm_iio_channel_release);



struct iio_channel *iio_channel_get_all(struct device *dev)

{

	const char *name;

include/linux/iio/consumer.h

+27 −0
Original line number Diff line number Diff line
@@ -48,6 +48,33 @@ 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.