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/compiler.h> 18 #include <linux/kernel.h> 19 #include <linux/errno.h> 20 #include <linux/gpio.h> 21 #include <linux/of.h> 22 23 struct device_node; 24 25 /* 26 * This is Linux-specific flags. By default controllers' and Linux' mapping 27 * match, but GPIO controllers are free to translate their own flags to 28 * Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended. 29 */ 30 enum of_gpio_flags { 31 OF_GPIO_ACTIVE_LOW = 0x1, 32 }; 33 34 #ifdef CONFIG_OF_GPIO 35 36 /* 37 * OF GPIO chip for memory mapped banks 38 */ 39 struct of_mm_gpio_chip { 40 struct gpio_chip gc; 41 void (*save_regs)(struct of_mm_gpio_chip *mm_gc); 42 void __iomem *regs; 43 }; 44 45 static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc) 46 { 47 return container_of(gc, struct of_mm_gpio_chip, gc); 48 } 49 50 extern int of_get_named_gpio_flags(struct device_node *np, 51 const char *list_name, int index, enum of_gpio_flags *flags); 52 53 extern unsigned int of_gpio_count(struct device_node *np); 54 55 extern int of_mm_gpiochip_add(struct device_node *np, 56 struct of_mm_gpio_chip *mm_gc); 57 58 extern void of_gpiochip_add(struct gpio_chip *gc); 59 extern void of_gpiochip_remove(struct gpio_chip *gc); 60 extern struct gpio_chip *of_node_to_gpiochip(struct device_node *np); 61 extern int of_gpio_simple_xlate(struct gpio_chip *gc, 62 const struct of_phandle_args *gpiospec, 63 u32 *flags); 64 65 #else /* CONFIG_OF_GPIO */ 66 67 /* Drivers may not strictly depend on the GPIO support, so let them link. */ 68 static inline int of_get_named_gpio_flags(struct device_node *np, 69 const char *list_name, int index, enum of_gpio_flags *flags) 70 { 71 return -ENOSYS; 72 } 73 74 static inline unsigned int of_gpio_count(struct device_node *np) 75 { 76 return 0; 77 } 78 79 static inline int of_gpio_simple_xlate(struct gpio_chip *gc, 80 const struct of_phandle_args *gpiospec, 81 u32 *flags) 82 { 83 return -ENOSYS; 84 } 85 86 static inline void of_gpiochip_add(struct gpio_chip *gc) { } 87 static inline void of_gpiochip_remove(struct gpio_chip *gc) { } 88 89 #endif /* CONFIG_OF_GPIO */ 90 91 /** 92 * of_get_gpio_flags() - Get a GPIO number and flags to use with GPIO API 93 * @np: device node to get GPIO from 94 * @index: index of the GPIO 95 * @flags: a flags pointer to fill in 96 * 97 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 98 * value on the error condition. If @flags is not NULL the function also fills 99 * in flags for the GPIO. 100 */ 101 static inline int of_get_gpio_flags(struct device_node *np, int index, 102 enum of_gpio_flags *flags) 103 { 104 return of_get_named_gpio_flags(np, "gpios", index, flags); 105 } 106 107 /** 108 * of_get_named_gpio() - Get a GPIO number to use with GPIO API 109 * @np: device node to get GPIO from 110 * @propname: Name of property containing gpio specifier(s) 111 * @index: index of the GPIO 112 * 113 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 114 * value on the error condition. 115 */ 116 static inline int of_get_named_gpio(struct device_node *np, 117 const char *propname, int index) 118 { 119 return of_get_named_gpio_flags(np, propname, index, NULL); 120 } 121 122 /** 123 * of_get_gpio() - Get a GPIO number to use with GPIO API 124 * @np: device node to get GPIO from 125 * @index: index of the GPIO 126 * 127 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 128 * value on the error condition. 129 */ 130 static inline int of_get_gpio(struct device_node *np, int index) 131 { 132 return of_get_gpio_flags(np, index, NULL); 133 } 134 135 #endif /* __LINUX_OF_GPIO_H */ 136