1 /* 2 * OF helpers for the GPIO API 3 * 4 * Copyright (c) 2007-2008 MontaVista Software, Inc. 5 * 6 * Author: Anton Vorontsov <[email protected]> 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/compiler.h> 18 #include <linux/kernel.h> 19 #include <linux/errno.h> 20 #include <linux/gpio.h> 21 22 struct device_node; 23 24 /* 25 * This is Linux-specific flags. By default controllers' and Linux' mapping 26 * match, but GPIO controllers are free to translate their own flags to 27 * Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended. 28 */ 29 enum of_gpio_flags { 30 OF_GPIO_ACTIVE_LOW = 0x1, 31 }; 32 33 #ifdef CONFIG_OF_GPIO 34 35 /* 36 * Generic OF GPIO chip 37 */ 38 struct of_gpio_chip { 39 struct gpio_chip gc; 40 int gpio_cells; 41 int (*xlate)(struct of_gpio_chip *of_gc, struct device_node *np, 42 const void *gpio_spec, enum of_gpio_flags *flags); 43 }; 44 45 static inline struct of_gpio_chip *to_of_gpio_chip(struct gpio_chip *gc) 46 { 47 return container_of(gc, struct of_gpio_chip, gc); 48 } 49 50 /* 51 * OF GPIO chip for memory mapped banks 52 */ 53 struct of_mm_gpio_chip { 54 struct of_gpio_chip of_gc; 55 void (*save_regs)(struct of_mm_gpio_chip *mm_gc); 56 void __iomem *regs; 57 }; 58 59 static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc) 60 { 61 struct of_gpio_chip *of_gc = to_of_gpio_chip(gc); 62 63 return container_of(of_gc, struct of_mm_gpio_chip, of_gc); 64 } 65 66 extern int of_get_gpio_flags(struct device_node *np, int index, 67 enum of_gpio_flags *flags); 68 extern unsigned int of_gpio_count(struct device_node *np); 69 70 extern int of_mm_gpiochip_add(struct device_node *np, 71 struct of_mm_gpio_chip *mm_gc); 72 extern int of_gpio_simple_xlate(struct of_gpio_chip *of_gc, 73 struct device_node *np, 74 const void *gpio_spec, 75 enum of_gpio_flags *flags); 76 #else 77 78 /* Drivers may not strictly depend on the GPIO support, so let them link. */ 79 static inline int of_get_gpio_flags(struct device_node *np, int index, 80 enum of_gpio_flags *flags) 81 { 82 return -ENOSYS; 83 } 84 85 static inline unsigned int of_gpio_count(struct device_node *np) 86 { 87 return 0; 88 } 89 90 #endif /* CONFIG_OF_GPIO */ 91 92 /** 93 * of_get_gpio - Get a GPIO number to use with GPIO API 94 * @np: device node to get GPIO from 95 * @index: index of the GPIO 96 * 97 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 98 * value on the error condition. 99 */ 100 static inline int of_get_gpio(struct device_node *np, int index) 101 { 102 return of_get_gpio_flags(np, index, NULL); 103 } 104 105 #endif /* __LINUX_OF_GPIO_H */ 106