/*
* 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>
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 int of_get_named_gpio_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 int of_get_named_gpio_flags(struct device_node *np,
const char *list_name, int index, enum of_gpio_flags *flags)
{
return -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 */
/**
* 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_gpio_flags() - Get a GPIO number 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 number to use with Linux generic GPIO API, or one of the errno
* value on the error condition. If @flags is not NULL the function also fills
* in flags for the GPIO.
*/
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 */
