120 lines
3.0 KiB
C
120 lines
3.0 KiB
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 <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);
|