LXR linux/include/linux/basic_mmio

   1/*
   2 * Basic memory-mapped GPIO controllers.
   3 *
   4 * Copyright 2008 MontaVista Software, Inc.
   5 * Copyright 2008,2010 Anton Vorontsov <cbouatmailru@gmail.com>
   6 *
   7 * This program is free software; you can redistribute  it and/or modify it
   8 * under  the terms of  the GNU General  Public License as published by the
   9 * Free Software Foundation;  either version 2 of the  License, or (at your
  10 * option) any later version.
  11 */
  12
  13#ifndef __BASIC_MMIO_GPIO_H
  14#define __BASIC_MMIO_GPIO_H
  15
  16#include <linux/gpio.h>
  17#include <linux/types.h>
  18#include <linux/compiler.h>
  19#include <linux/spinlock_types.h>
  20
  21struct bgpio_pdata {
  22        int base;
  23        int ngpio;
  24};
  25
  26struct device;
  27
  28struct bgpio_chip {
  29        struct gpio_chip gc;
  30
  31        unsigned long (*read_reg)(void __iomem *reg);
  32        void (*write_reg)(void __iomem *reg, unsigned long data);
  33
  34        void __iomem *reg_dat;
  35        void __iomem *reg_set;
  36        void __iomem *reg_clr;
  37        void __iomem *reg_dir;
  38
  39        /* Number of bits (GPIOs): <register width> * 8. */
  40        int bits;
  41
  42        /*
  43         * Some GPIO controllers work with the big-endian bits notation,
  44         * e.g. in a 8-bits register, GPIO7 is the least significant bit.
  45         */
  46        unsigned long (*pin2mask)(struct bgpio_chip *bgc, unsigned int pin);
  47
  48        /*
  49         * Used to lock bgpio_chip->data. Also, this is needed to keep
  50         * shadowed and real data registers writes together.
  51         */
  52        spinlock_t lock;
  53
  54        /* Shadowed data register to clear/set bits safely. */
  55        unsigned long data;
  56
  57        /* Shadowed direction registers to clear/set direction safely. */
  58        unsigned long dir;
  59};
  60
  61static inline struct bgpio_chip *to_bgpio_chip(struct gpio_chip *gc)
  62{
  63        return container_of(gc, struct bgpio_chip, gc);
  64}
  65
  66int bgpio_remove(struct bgpio_chip *bgc);
  67int bgpio_init(struct bgpio_chip *bgc, struct device *dev,
  68               unsigned long sz, void __iomem *dat, void __iomem *set,
  69               void __iomem *clr, void __iomem *dirout, void __iomem *dirin,
  70               unsigned long flags);
  71
  72#define BGPIOF_BIG_ENDIAN               BIT(0)
  73#define BGPIOF_UNREADABLE_REG_SET       BIT(1) /* reg_set is unreadable */
  74#define BGPIOF_UNREADABLE_REG_DIR       BIT(2) /* reg_dir is unreadable */
  75
  76#endif /* __BASIC_MMIO_GPIO_H */
  77