/*
 * 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
 * @flags:      optional GPIO initialization flags
 *
 * 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,
                                              enum gpiod_flags flags)
{
        return devm_gpiod_get_index(dev, con_id, 0, flags);
}
EXPORT_SYMBOL(__devm_gpiod_get);

/**
 * devm_gpiod_get_optional - Resource-managed gpiod_get_optional()
 * @dev: GPIO consumer
 * @con_id: function within the GPIO consumer
 * @flags: optional GPIO initialization flags
 *
 * 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,
                                                       enum gpiod_flags flags)
{
        return devm_gpiod_get_index_optional(dev, con_id, 0, flags);
}
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
 * @flags:      optional GPIO initialization flags
 *
 * 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,
                                                    enum gpiod_flags flags)
{
        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, flags);
        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
 * @flags: optional GPIO initialization flags
 *
 * 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,
                                                         enum gpiod_flags flags)
{
        struct gpio_desc *desc;

        desc = devm_gpiod_get_index(dev, con_id, index, flags);
        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);