Unverified Commit 891ddbc7 authored by Linus Walleij's avatar Linus Walleij Committed by Mark Brown
Browse files

gpio: Add devm_gpiod_unhinge() 



This adds a function named devm_gpiod_unhinge() that removes
the resource management from a GPIO descriptor.

I am not sure if this is the best anglosaxon name for the
function, no other managed resources have an equivalent
currently, but I chose "unhinge" as the closest intuitive
thing I could imagine that fits Rusty Russell's API design
criterions "the obvious use is the correct one" and
"the name tells you how to use it".

The idea came out of a remark from Mark Brown that it should
be possible to handle over management of a resource from
devres to the regulator core, and indeed we can do that.

Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Tested-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: default avatarCharles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent cb28ee38

Documentation/driver-model/devres.txt

+1 −0
Original line number Diff line number Diff line
@@ -254,6 +254,7 @@ GPIO 
  devm_gpiod_get_index_optional()

  devm_gpiod_get_optional()

  devm_gpiod_put()

  devm_gpiod_unhinge()

  devm_gpiochip_add_data()

  devm_gpiochip_remove()

  devm_gpio_request()

drivers/gpio/gpiolib-devres.c

+30 −0
Original line number Diff line number Diff line
@@ -346,6 +346,36 @@ void devm_gpiod_put(struct device *dev, struct gpio_desc *desc) 
}

EXPORT_SYMBOL(devm_gpiod_put);



/**

 * devm_gpiod_unhinge - Remove resource management from a gpio descriptor

 * @dev:	GPIO consumer

 * @desc:	GPIO descriptor to remove resource management from

 *

 * Remove resource management from a GPIO descriptor. This is needed when

 * you want to hand over lifecycle management of a descriptor to another

 * mechanism.

 */



void devm_gpiod_unhinge(struct device *dev, struct gpio_desc *desc)

{

	int ret;



	if (IS_ERR_OR_NULL(desc))

		return;

	ret = devres_destroy(dev, devm_gpiod_release,

			     devm_gpiod_match, &desc);

	/*

	 * If the GPIO descriptor is requested as nonexclusive, we

	 * may call this function several times on the same descriptor

	 * so it is OK if devres_destroy() returns -ENOENT.

	 */

	if (ret == -ENOENT)

		return;

	/* Anything else we should warn about */

	WARN_ON(ret);

}

EXPORT_SYMBOL(devm_gpiod_unhinge);



/**

 * devm_gpiod_put_array - Resource-managed gpiod_put_array()

 * @dev:	GPIO consumer

include/linux/gpio/consumer.h

+10 −0
Original line number Diff line number Diff line
@@ -104,6 +104,7 @@ struct gpio_descs *__must_check 
devm_gpiod_get_array_optional(struct device *dev, const char *con_id,

			      enum gpiod_flags flags);

void devm_gpiod_put(struct device *dev, struct gpio_desc *desc);

void devm_gpiod_unhinge(struct device *dev, struct gpio_desc *desc);

void devm_gpiod_put_array(struct device *dev, struct gpio_descs *descs);



int gpiod_get_direction(struct gpio_desc *desc);
@@ -249,6 +250,15 @@ static inline void gpiod_put(struct gpio_desc *desc) 
	WARN_ON(1);

}



static inline void devm_gpiod_unhinge(struct device *dev,

				      struct gpio_desc *desc)

{

	might_sleep();



	/* GPIO can never have been requested */

	WARN_ON(1);

}



static inline void gpiod_put_array(struct gpio_descs *descs)

{

	might_sleep();

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