basic_mmio_gpio.h

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/*
 * Basic memory-mapped GPIO controllers.
 *
 * Copyright 2008 MontaVista Software, Inc.
 * Copyright 2008,2010 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 __BASIC_MMIO_GPIO_H
#define __BASIC_MMIO_GPIO_H

#include <linux/gpio.h>
#include <linux/types.h>
#include <linux/compiler.h>
#include <linux/spinlock_types.h>

struct bgpio_pdata {
    int base;
    int ngpio;
};

struct device;

struct bgpio_chip {
    struct gpio_chip gc;

    unsigned long (*read_reg)(void __iomem *reg);
    void (*write_reg)(void __iomem *reg, unsigned long data);

    void __iomem *reg_dat;
    void __iomem *reg_set;
    void __iomem *reg_clr;
    void __iomem *reg_dir;

    /* Number of bits (GPIOs): <register width> * 8. */
    int bits;

    /*
     * Some GPIO controllers work with the big-endian bits notation,
     * e.g. in a 8-bits register, GPIO7 is the least significant bit.
     */
    unsigned long (*pin2mask)(struct bgpio_chip *bgc, unsigned int pin);

    /*
     * Used to lock bgpio_chip->data. Also, this is needed to keep
     * shadowed and real data registers writes together.
     */
    spinlock_t lock;

    /* Shadowed data register to clear/set bits safely. */
    unsigned long data;

    /* Shadowed direction registers to clear/set direction safely. */
    unsigned long dir;
};

static inline struct bgpio_chip *to_bgpio_chip(struct gpio_chip *gc)
{
    return container_of(gc, struct bgpio_chip, gc);
}

int bgpio_remove(struct bgpio_chip *bgc);
int bgpio_init(struct bgpio_chip *bgc, struct device *dev,
           unsigned long sz, void __iomem *dat, void __iomem *set,
           void __iomem *clr, void __iomem *dirout, void __iomem *dirin,
           unsigned long flags);

#define BGPIOF_BIG_ENDIAN       BIT(0)
#define BGPIOF_UNREADABLE_REG_SET   BIT(1) /* reg_set is unreadable */
#define BGPIOF_UNREADABLE_REG_DIR   BIT(2) /* reg_dir is unreadable */

#endif /* __BASIC_MMIO_GPIO_H */