/*
   * OF helpers for the GPIO API
   *
   * Copyright (c) 2007-2008  MontaVista Software, Inc.
   *
   * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   */
  
  #ifndef __LINUX_OF_GPIO_H
  #define __LINUX_OF_GPIO_H
  
  #include <linux/compiler.h>
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/gpio.h>
  #include <linux/of.h>
  #include <linux/gpio/consumer.h>
  
  struct device_node;
  
  /*
   * This is Linux-specific flags. By default controllers' and Linux' mapping
   * match, but GPIO controllers are free to translate their own flags to
   * Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended.
   */
  enum of_gpio_flags {
  	OF_GPIO_ACTIVE_LOW = 0x1,
  };
  
  #ifdef CONFIG_OF_GPIO
  
  /*
   * OF GPIO chip for memory mapped banks
   */
  struct of_mm_gpio_chip {
  	struct gpio_chip gc;
  	void (*save_regs)(struct of_mm_gpio_chip *mm_gc);
  	void __iomem *regs;
  };
  
  static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc)
  {
  	return container_of(gc, struct of_mm_gpio_chip, gc);
  }
  
  extern struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
  		const char *list_name, int index, enum of_gpio_flags *flags);
  
  extern int of_mm_gpiochip_add(struct device_node *np,
  			      struct of_mm_gpio_chip *mm_gc);
  
  extern void of_gpiochip_add(struct gpio_chip *gc);
  extern void of_gpiochip_remove(struct gpio_chip *gc);
  extern int of_gpio_simple_xlate(struct gpio_chip *gc,
  				const struct of_phandle_args *gpiospec,
  				u32 *flags);
  
  #else /* CONFIG_OF_GPIO */
  
  /* Drivers may not strictly depend on the GPIO support, so let them link. */
  static inline struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
  		const char *list_name, int index, enum of_gpio_flags *flags)
  {
  	return ERR_PTR(-ENOSYS);
  }
  
  static inline int of_gpio_simple_xlate(struct gpio_chip *gc,
  				       const struct of_phandle_args *gpiospec,
  				       u32 *flags)
  {
  	return -ENOSYS;
  }
  
  static inline void of_gpiochip_add(struct gpio_chip *gc) { }
  static inline void of_gpiochip_remove(struct gpio_chip *gc) { }
  
  #endif /* CONFIG_OF_GPIO */
  
  static inline int of_get_named_gpio_flags(struct device_node *np,
  		const char *list_name, int index, enum of_gpio_flags *flags)
  {
  	struct gpio_desc *desc;
  	desc = of_get_named_gpiod_flags(np, list_name, index, flags);
  
  	if (IS_ERR(desc))
  		return PTR_ERR(desc);
  	else
  		return desc_to_gpio(desc);
  }
  
  /**
   * of_gpio_named_count() - Count GPIOs for a device
   * @np:		device node to count GPIOs for
   * @propname:	property name containing gpio specifier(s)
   *
   * The function returns the count of GPIOs specified for a node.
   * Note that the empty GPIO specifiers count too. Returns either
   *   Number of gpios defined in property,
   *   -EINVAL for an incorrectly formed gpios property, or
   *   -ENOENT for a missing gpios property
   *
   * Example:
   * gpios = <0
   *          &gpio1 1 2
   *          0
   *          &gpio2 3 4>;
   *
   * The above example defines four GPIOs, two of which are not specified.
   * This function will return '4'
   */
  static inline int of_gpio_named_count(struct device_node *np, const char* propname)
  {
  	return of_count_phandle_with_args(np, propname, "#gpio-cells");
  }
  
  /**
   * of_gpio_count() - Count GPIOs for a device
   * @np:		device node to count GPIOs for
   *
   * Same as of_gpio_named_count, but hard coded to use the 'gpios' property
   */
  static inline int of_gpio_count(struct device_node *np)
  {
  	return of_gpio_named_count(np, "gpios");
  }
  
  /**
   * of_get_gpiod_flags() - Get a GPIO descriptor and flags to use with GPIO API
   * @np:		device node to get GPIO from
   * @index:	index of the GPIO
   * @flags:	a flags pointer to fill in
   *
   * Returns GPIO descriptor to use with Linux generic GPIO API, or a errno
   * value on the error condition. If @flags is not NULL the function also fills
   * in flags for the GPIO.
   */
  static inline struct gpio_desc *of_get_gpiod_flags(struct device_node *np,
  					int index, enum of_gpio_flags *flags)
  {
  	return of_get_named_gpiod_flags(np, "gpios", index, flags);
  }
  
  static inline int of_get_gpio_flags(struct device_node *np, int index,
  		      enum of_gpio_flags *flags)
  {
  	return of_get_named_gpio_flags(np, "gpios", index, flags);
  }
  
  /**
   * of_get_named_gpio() - Get a GPIO number to use with GPIO API
   * @np:		device node to get GPIO from
   * @propname:	Name of property containing gpio specifier(s)
   * @index:	index of the GPIO
   *
   * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
   * value on the error condition.
   */
  static inline int of_get_named_gpio(struct device_node *np,
                                     const char *propname, int index)
  {
  	return of_get_named_gpio_flags(np, propname, index, NULL);
  }
  
  /**
   * of_get_gpio() - Get a GPIO number to use with GPIO API
   * @np:		device node to get GPIO from
   * @index:	index of the GPIO
   *
   * Returns GPIO number to use with Linux generic GPIO API, or one of the errno
   * value on the error condition.
   */
  static inline int of_get_gpio(struct device_node *np, int index)
  {
  	return of_get_gpio_flags(np, index, NULL);
  }
  
  #endif /* __LINUX_OF_GPIO_H */