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 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 * OF GPIO chip for memory mapped banks 37 */ 38 struct of_mm_gpio_chip { 39 struct gpio_chip gc; 40 void (*save_regs)(struct of_mm_gpio_chip *mm_gc); 41 void __iomem *regs; 42 }; 43 44 static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc) 45 { 46 return container_of(gc, struct of_mm_gpio_chip, gc); 47 } 48 49 extern int of_get_named_gpio_flags(struct device_node *np, 50 const char *list_name, int index, enum of_gpio_flags *flags); 51 52 extern unsigned int of_gpio_count(struct device_node *np); 53 54 extern int of_mm_gpiochip_add(struct device_node *np, 55 struct of_mm_gpio_chip *mm_gc); 56 57 extern void of_gpiochip_add(struct gpio_chip *gc); 58 extern void of_gpiochip_remove(struct gpio_chip *gc); 59 extern struct gpio_chip *of_node_to_gpiochip(struct device_node *np); 60 extern int of_gpio_simple_xlate(struct gpio_chip *gc, struct device_node *np, 61 const void *gpio_spec, u32 *flags); 62 63 #else /* CONFIG_OF_GPIO */ 64 65 /* Drivers may not strictly depend on the GPIO support, so let them link. */ 66 static inline int of_get_named_gpio_flags(struct device_node *np, 67 const char *list_name, int index, enum of_gpio_flags *flags) 68 { 69 return -ENOSYS; 70 } 71 72 static inline unsigned int of_gpio_count(struct device_node *np) 73 { 74 return 0; 75 } 76 77 static inline int of_gpio_simple_xlate(struct gpio_chip *gc, 78 struct device_node *np, 79 const void *gpio_spec, u32 *flags) 80 { 81 return -ENOSYS; 82 } 83 84 static inline void of_gpiochip_add(struct gpio_chip *gc) { } 85 static inline void of_gpiochip_remove(struct gpio_chip *gc) { } 86 87 #endif /* CONFIG_OF_GPIO */ 88 89 /** 90 * of_get_gpio_flags() - Get a GPIO number and flags to use with GPIO API 91 * @np: device node to get GPIO from 92 * @index: index of the GPIO 93 * @flags: a flags pointer to fill in 94 * 95 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 96 * value on the error condition. If @flags is not NULL the function also fills 97 * in flags for the GPIO. 98 */ 99 static inline int of_get_gpio_flags(struct device_node *np, int index, 100 enum of_gpio_flags *flags) 101 { 102 return of_get_named_gpio_flags(np, "gpios", index, flags); 103 } 104 105 /** 106 * of_get_named_gpio() - Get a GPIO number to use with GPIO API 107 * @np: device node to get GPIO from 108 * @propname: Name of property containing gpio specifier(s) 109 * @index: index of the GPIO 110 * 111 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 112 * value on the error condition. 113 */ 114 static inline int of_get_named_gpio(struct device_node *np, 115 const char *propname, int index) 116 { 117 return of_get_named_gpio_flags(np, propname, index, NULL); 118 } 119 120 /** 121 * of_get_gpio() - Get a GPIO number to use with GPIO API 122 * @np: device node to get GPIO from 123 * @index: index of the GPIO 124 * 125 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 126 * value on the error condition. 127 */ 128 static inline int of_get_gpio(struct device_node *np, int index) 129 { 130 return of_get_gpio_flags(np, index, NULL); 131 } 132 133 #endif /* __LINUX_OF_GPIO_H */ 134