include/linux/of_gpio.h

   1 /*
   2  * OF helpers for the GPIO API
   3  *
   4  * Copyright (c) 2007-2008  MontaVista Software, Inc.
   5  *
   6  * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  */
  13
  14 #ifndef __LINUX_OF_GPIO_H
  15 #define __LINUX_OF_GPIO_H
  16
  17 #include <linux/errno.h>
  18 #include <asm/gpio.h>
  19
  20 #ifdef CONFIG_OF_GPIO
  21
  22 /*
  23  * Generic OF GPIO chip
  24  */
  25 struct of_gpio_chip {
  26         struct gpio_chip gc;
  27         int gpio_cells;
  28         int (*xlate)(struct of_gpio_chip *of_gc, struct device_node *np,
  29                      const void *gpio_spec);
  30 };
  31
  32 static inline struct of_gpio_chip *to_of_gpio_chip(struct gpio_chip *gc)
  33 {
  34         return container_of(gc, struct of_gpio_chip, gc);
  35 }
  36
  37 /*
  38  * OF GPIO chip for memory mapped banks
  39  */
  40 struct of_mm_gpio_chip {
  41         struct of_gpio_chip of_gc;
  42         void (*save_regs)(struct of_mm_gpio_chip *mm_gc);
  43         void __iomem *regs;
  44 };
  45
  46 static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc)
  47 {
  48         struct of_gpio_chip *of_gc = to_of_gpio_chip(gc);
  49
  50         return container_of(of_gc, struct of_mm_gpio_chip, of_gc);
  51 }
  52
  53 extern int of_get_gpio(struct device_node *np, int index);
  54 extern int of_mm_gpiochip_add(struct device_node *np,
  55                               struct of_mm_gpio_chip *mm_gc);
  56 extern int of_gpio_simple_xlate(struct of_gpio_chip *of_gc,
  57                                 struct device_node *np,
  58                                 const void *gpio_spec);
  59 #else
  60
  61 /* Drivers may not strictly depend on the GPIO support, so let them link. */
  62 static inline int of_get_gpio(struct device_node *np, int index)
  63 {
  64         return -ENOSYS;
  65 }
  66
  67 #endif /* CONFIG_OF_GPIO */
  68
  69 #endif /* __LINUX_OF_GPIO_H */