of_gpio.h

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/*
 * OF helpers for the GPIO API
 *
 * Copyright (c) 2007-2008  MontaVista Software, Inc.
 *
 * Author: Anton Vorontsov <[email protected]>
 *
 * 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 unsigned int of_gpio_named_count(struct device_node *np,
                    const char* propname);

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 unsigned int of_gpio_named_count(struct device_node *np,
                    const char* propname)
{
    return 0;
}

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 unsigned int of_gpio_count(struct device_node *np)
{
    return of_gpio_named_count(np, "gpios");
}

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);
}

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);
}

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 */