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/*
* 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 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);
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