/* * 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 <blogic@openwrt.org> */ #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 an interrupt *      @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);