/*
* 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/err.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/device.h>
#include <linux/gfp.h>
static void devm_gpiod_release(struct device *dev, void *res)
{
struct gpio_desc **desc = res;
gpiod_put(*desc);
}
static int devm_gpiod_match(struct device *dev, void *res, void *data)
{
struct gpio_desc **this = res, **gpio = data;
return *this == *gpio;
}
/**
* devm_gpiod_get - Resource-managed gpiod_get()
* @dev: GPIO consumer
* @con_id: function within the GPIO consumer
*
* Managed gpiod_get(). GPIO descriptors returned from this function are
* automatically disposed on driver detach. See gpiod_get() for detailed
* information about behavior and return values.
*/
struct gpio_desc *__must_check devm_gpiod_get(struct device *dev,
const char *con_id)
{
return devm_gpiod_get_index(dev, con_id, 0);
}
EXPORT_SYMBOL(devm_gpiod_get);
/**
* devm_gpiod_get_optional - Resource-managed gpiod_get_optional()
* @dev: GPIO consumer
* @con_id: function within the GPIO consumer
*
* Managed gpiod_get_optional(). GPIO descriptors returned from this function
* are automatically disposed on driver detach. See gpiod_get_optional() for
* detailed information about behavior and return values.
*/
struct gpio_desc *__must_check devm_gpiod_get_optional(struct device *dev,
const char *con_id)
{
return devm_gpiod_get_index_optional(dev, con_id, 0);
}
EXPORT_SYMBOL(devm_gpiod_get_optional);
/**
* devm_gpiod_get_index - Resource-managed gpiod_get_index()
* @dev: GPIO consumer
* @con_id: function within the GPIO consumer
* @idx: index of the GPIO to obtain in the consumer
*
* Managed gpiod_get_index(). GPIO descriptors returned from this function are
* automatically disposed on driver detach. See gpiod_get_index() for detailed
* information about behavior and return values.
*/
struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
const char *con_id,
unsigned int idx)
{
struct gpio_desc **dr;
struct gpio_desc *desc;
dr = devres_alloc(devm_gpiod_release, sizeof(struct gpiod_desc *),
GFP_KERNEL);
if (!dr)
return ERR_PTR(-ENOMEM);
desc = gpiod_get_index(dev, con_id, idx);
if (IS_ERR(desc)) {
devres_free(dr);
return desc;
}
*dr = desc;
devres_add(dev, dr);
return desc;
}
EXPORT_SYMBOL(devm_gpiod_get_index);
/**
* devm_gpiod_get_index_optional - Resource-managed gpiod_get_index_optional()
* @dev: GPIO consumer
* @con_id: function within the GPIO consumer
* @index: index of the GPIO to obtain in the consumer
*
* Managed gpiod_get_index_optional(). GPIO descriptors returned from this
* function are automatically disposed on driver detach. See
* gpiod_get_index_optional() for detailed information about behavior and
* return values.
*/
struct gpio_desc *__must_check devm_gpiod_get_index_optional(struct device *dev,
const char *con_id,
unsigned int index)
{
struct gpio_desc *desc;
desc = devm_gpiod_get_index(dev, con_id, index);
if (IS_ERR(desc)) {
if (PTR_ERR(desc) == -ENOENT)
return NULL;
}
return desc;
}
EXPORT_SYMBOL(devm_gpiod_get_index_optional);
/**
* devm_gpiod_put - Resource-managed gpiod_put()
* @desc: GPIO descriptor to dispose of
*
* Dispose of a GPIO descriptor obtained with devm_gpiod_get() or
* devm_gpiod_get_index(). Normally this function will not be called as the GPIO
* will be disposed of by the resource management code.
*/
void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
{
WARN_ON(devres_release(dev, devm_gpiod_release, devm_gpiod_match,
&desc));
}
EXPORT_SYMBOL(devm_gpiod_put);
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);
