/*
   * 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_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_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);