[linux.git] / drivers / gpio / devres.c

/*
 * drivers/gpio/devres.c - managed gpio resources
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * This file is based on kernel/irq/devres.c
 *
 * Copyright (c) 2011 John Crispin <[email protected]>
 */

#include <linux/module.h>
#include <linux/gpio.h>
#include <linux/device.h>
#include <linux/gfp.h>

static void devm_gpio_release(struct device *dev, void *res)
{
	unsigned *gpio = res;

	gpio_free(*gpio);
}

static int devm_gpio_match(struct device *dev, void *res, void *data)
{
	unsigned *this = res, *gpio = data;

	return *this == *gpio;
}

/**
 *      devm_gpio_request - request a GPIO for a managed device
 *      @dev: device to request the GPIO for
 *      @gpio: GPIO to allocate
 *      @label: the name of the requested GPIO
 *
 *      Except for the extra @dev argument, this function takes the
 *      same arguments and performs the same function as
 *      gpio_request().  GPIOs requested with this function will be
 *      automatically freed on driver detach.
 *
 *      If an GPIO allocated with this function needs to be freed
 *      separately, devm_gpio_free() must be used.
 */

int devm_gpio_request(struct device *dev, unsigned gpio, const char *label)
{
	unsigned *dr;
	int rc;

	dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
	if (!dr)
		return -ENOMEM;

	rc = gpio_request(gpio, label);
	if (rc) {
		devres_free(dr);
		return rc;
	}

	*dr = gpio;
	devres_add(dev, dr);

	return 0;
}
EXPORT_SYMBOL(devm_gpio_request);

/**
 *	devm_gpio_request_one - request a single GPIO with initial setup
 *	@dev:   device to request for
 *	@gpio:	the GPIO number
 *	@flags:	GPIO configuration as specified by GPIOF_*
 *	@label:	a literal description string of this GPIO
 */
int devm_gpio_request_one(struct device *dev, unsigned gpio,
			  unsigned long flags, const char *label)
{
	unsigned *dr;
	int rc;

	dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
	if (!dr)
		return -ENOMEM;

	rc = gpio_request_one(gpio, flags, label);
	if (rc) {
		devres_free(dr);
		return rc;
	}

	*dr = gpio;
	devres_add(dev, dr);

	return 0;
}
EXPORT_SYMBOL(devm_gpio_request_one);

/**
 *      devm_gpio_free - free a GPIO
 *      @dev: device to free GPIO for
 *      @gpio: GPIO to free
 *
 *      Except for the extra @dev argument, this function takes the
 *      same arguments and performs the same function as gpio_free().
 *      This function instead of gpio_free() should be used to manually
 *      free GPIOs allocated with devm_gpio_request().
 */
void devm_gpio_free(struct device *dev, unsigned int gpio)
{

	WARN_ON(devres_release(dev, devm_gpio_release, devm_gpio_match,
		&gpio));
}
EXPORT_SYMBOL(devm_gpio_free);
Commit	Line	Data
1a0703ed JC	1	/*
	2	* drivers/gpio/devres.c - managed gpio resources
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2
	6	* as published by the Free Software Foundation.
	7	*
	8	* You should have received a copy of the GNU General Public License
	9	* along with this program; if not, write to the Free Software
	10	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	11	*
	12	* This file is based on kernel/irq/devres.c
	13	*
	14	* Copyright (c) 2011 John Crispin <[email protected]>
	15	*/
	16
	17	#include <linux/module.h>
	18	#include <linux/gpio.h>
	19	#include <linux/device.h>
	20	#include <linux/gfp.h>
	21
	22	static void devm_gpio_release(struct device dev, void res)
	23	{
	24	unsigned *gpio = res;
	25
	26	gpio_free(*gpio);
	27	}
	28
	29	static int devm_gpio_match(struct device dev, void res, void *data)
	30	{
	31	unsigned this = res, gpio = data;
	32
	33	return this == gpio;
	34	}
	35
	36	/**
713b7ef8 WS	37	* devm_gpio_request - request a GPIO for a managed device
	38	* @dev: device to request the GPIO for
	39	* @gpio: GPIO to allocate
	40	* @label: the name of the requested GPIO
1a0703ed JC	41	*
	42	* Except for the extra @dev argument, this function takes the
	43	* same arguments and performs the same function as
	44	* gpio_request(). GPIOs requested with this function will be
	45	* automatically freed on driver detach.
	46	*
	47	* If an GPIO allocated with this function needs to be freed
	48	* separately, devm_gpio_free() must be used.
	49	*/
	50
	51	int devm_gpio_request(struct device dev, unsigned gpio, const char label)
	52	{
	53	unsigned *dr;
	54	int rc;
	55
	56	dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
	57	if (!dr)
	58	return -ENOMEM;
	59
	60	rc = gpio_request(gpio, label);
	61	if (rc) {
	62	devres_free(dr);
	63	return rc;
	64	}
	65
	66	*dr = gpio;
	67	devres_add(dev, dr);
	68
	69	return 0;
	70	}
	71	EXPORT_SYMBOL(devm_gpio_request);
	72
09d71ff1 MB	73	/**
	74	* devm_gpio_request_one - request a single GPIO with initial setup
	75	* @dev: device to request for
	76	* @gpio: the GPIO number
	77	* @flags: GPIO configuration as specified by GPIOF_*
	78	* @label: a literal description string of this GPIO
	79	*/
	80	int devm_gpio_request_one(struct device *dev, unsigned gpio,
	81	unsigned long flags, const char *label)
	82	{
	83	unsigned *dr;
	84	int rc;
	85
	86	dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
	87	if (!dr)
	88	return -ENOMEM;
	89
	90	rc = gpio_request_one(gpio, flags, label);
	91	if (rc) {
	92	devres_free(dr);
	93	return rc;
	94	}
	95
	96	*dr = gpio;
	97	devres_add(dev, dr);
	98
	99	return 0;
	100	}
3996bfc7	101	EXPORT_SYMBOL(devm_gpio_request_one);
09d71ff1	102
1a0703ed	103	/**
713b7ef8 WS	104	* devm_gpio_free - free a GPIO
	105	* @dev: device to free GPIO for
	106	* @gpio: GPIO to free
1a0703ed JC	107	*
	108	* Except for the extra @dev argument, this function takes the
	109	* same arguments and performs the same function as gpio_free().
	110	* This function instead of gpio_free() should be used to manually
	111	* free GPIOs allocated with devm_gpio_request().
	112	*/
	113	void devm_gpio_free(struct device *dev, unsigned int gpio)
	114	{
	115
a85990b3	116	WARN_ON(devres_release(dev, devm_gpio_release, devm_gpio_match,
1a0703ed	117	&gpio));
1a0703ed JC	118	}
1a0703ed JC	119	EXPORT_SYMBOL(devm_gpio_free);