include/linux/basic_mmio_gpio.h

   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
  21 struct bgpio_pdata {
  22         const char *label;
  23         int base;
  24         int ngpio;
  25 };
  26
  27 struct device;
  28
  29 struct bgpio_chip {
  30         struct gpio_chip gc;
  31
  32         unsigned long (*read_reg)(void __iomem *reg);
  33         void (*write_reg)(void __iomem *reg, unsigned long data);
  34
  35         void __iomem *reg_dat;
  36         void __iomem *reg_set;
  37         void __iomem *reg_clr;
  38         void __iomem *reg_dir;
  39
  40         /* Number of bits (GPIOs): <register width> * 8. */
  41         int bits;
  42
  43         /*
  44          * Some GPIO controllers work with the big-endian bits notation,
  45          * e.g. in a 8-bits register, GPIO7 is the least significant bit.
  46          */
  47         unsigned long (*pin2mask)(struct bgpio_chip *bgc, unsigned int pin);
  48
  49         /*
  50          * Used to lock bgpio_chip->data. Also, this is needed to keep
  51          * shadowed and real data registers writes together.
  52          */
  53         spinlock_t lock;
  54
  55         /* Shadowed data register to clear/set bits safely. */
  56         unsigned long data;
  57
  58         /* Shadowed direction registers to clear/set direction safely. */
  59         unsigned long dir;
  60 };
  61
  62 static inline struct bgpio_chip *to_bgpio_chip(struct gpio_chip *gc)
  63 {
  64         return container_of(gc, struct bgpio_chip, gc);
  65 }
  66
  67 int bgpio_remove(struct bgpio_chip *bgc);
  68 int bgpio_init(struct bgpio_chip *bgc, struct device *dev,
  69                unsigned long sz, void __iomem *dat, void __iomem *set,
  70                void __iomem *clr, void __iomem *dirout, void __iomem *dirin,
  71                unsigned long flags);
  72
  73 #define BGPIOF_BIG_ENDIAN               BIT(0)
  74 #define BGPIOF_UNREADABLE_REG_SET       BIT(1) /* reg_set is unreadable */
  75 #define BGPIOF_UNREADABLE_REG_DIR       BIT(2) /* reg_dir is unreadable */
  76 #define BGPIOF_BIG_ENDIAN_BYTE_ORDER    BIT(3)
  77
  78 #endif /* __BASIC_MMIO_GPIO_H */