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         int base;
  23         int ngpio;
  24 };
  25
  26 struct device;
  27
  28 struct 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
  61 static inline struct bgpio_chip *to_bgpio_chip(struct gpio_chip *gc)
  62 {
  63         return container_of(gc, struct bgpio_chip, gc);
  64 }
  65
  66 int bgpio_remove(struct bgpio_chip *bgc);
  67 int 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 #define BGPIOF_BIG_ENDIAN_BYTE_ORDER    BIT(3)
  76
  77 #endif /* __BASIC_MMIO_GPIO_H */