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 <blogic@openwrt.org>
 15 */
 16
 17#include <linux/module.h>
 18#include <linux/gpio.h>
 19#include <linux/device.h>
 20#include <linux/gfp.h>
 21
 22static void devm_gpio_release(struct device *dev, void *res)
 23{
 24	unsigned *gpio = res;
 25
 26	gpio_free(*gpio);
 27}
 28
 29static 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/**
 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
 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
 51int 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}
 71EXPORT_SYMBOL(devm_gpio_request);
 72
 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 */
 80int 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}
101EXPORT_SYMBOL(devm_gpio_request_one);
102
103/**
104 *      devm_gpio_free - free an interrupt
105 *      @dev: device to free gpio for
106 *      @gpio: gpio to free
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 */
113void devm_gpio_free(struct device *dev, unsigned int gpio)
114{
115
116	WARN_ON(devres_release(dev, devm_gpio_release, devm_gpio_match,
117		&gpio));
118}
119EXPORT_SYMBOL(devm_gpio_free);