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_named_count(struct device_node *np, 54 const char* propname); 55 56 extern int of_mm_gpiochip_add(struct device_node *np, 57 struct of_mm_gpio_chip *mm_gc); 58 59 extern void of_gpiochip_add(struct gpio_chip *gc); 60 extern void of_gpiochip_remove(struct gpio_chip *gc); 61 extern struct gpio_chip *of_node_to_gpiochip(struct device_node *np); 62 extern int of_gpio_simple_xlate(struct gpio_chip *gc, 63 const struct of_phandle_args *gpiospec, 64 u32 *flags); 65 66 #else /* CONFIG_OF_GPIO */ 67 68 /* Drivers may not strictly depend on the GPIO support, so let them link. */ 69 static inline int of_get_named_gpio_flags(struct device_node *np, 70 const char *list_name, int index, enum of_gpio_flags *flags) 71 { 72 return -ENOSYS; 73 } 74 75 static inline unsigned int of_gpio_named_count(struct device_node *np, 76 const char* propname) 77 { 78 return 0; 79 } 80 81 static inline int of_gpio_simple_xlate(struct gpio_chip *gc, 82 const struct of_phandle_args *gpiospec, 83 u32 *flags) 84 { 85 return -ENOSYS; 86 } 87 88 static inline void of_gpiochip_add(struct gpio_chip *gc) { } 89 static inline void of_gpiochip_remove(struct gpio_chip *gc) { } 90 91 #endif /* CONFIG_OF_GPIO */ 92 93 /** 94 * of_gpio_count - Count GPIOs for a device 95 * @np: device node to count GPIOs for 96 * 97 * The function returns the count of GPIOs specified for a node. 98 * 99 * Note that the empty GPIO specifiers counts too. For example, 100 * 101 * gpios = <0 102 * &pio1 1 2 103 * 0 104 * &pio2 3 4>; 105 * 106 * defines four GPIOs (so this function will return 4), two of which 107 * are not specified. 108 */ 109 static inline unsigned int of_gpio_count(struct device_node *np) 110 { 111 return of_gpio_named_count(np, "gpios"); 112 } 113 114 /** 115 * of_get_gpio_flags() - Get a GPIO number and flags to use with GPIO API 116 * @np: device node to get GPIO from 117 * @index: index of the GPIO 118 * @flags: a flags pointer to fill in 119 * 120 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 121 * value on the error condition. If @flags is not NULL the function also fills 122 * in flags for the GPIO. 123 */ 124 static inline int of_get_gpio_flags(struct device_node *np, int index, 125 enum of_gpio_flags *flags) 126 { 127 return of_get_named_gpio_flags(np, "gpios", index, flags); 128 } 129 130 /** 131 * of_get_named_gpio() - Get a GPIO number to use with GPIO API 132 * @np: device node to get GPIO from 133 * @propname: Name of property containing gpio specifier(s) 134 * @index: index of the GPIO 135 * 136 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 137 * value on the error condition. 138 */ 139 static inline int of_get_named_gpio(struct device_node *np, 140 const char *propname, int index) 141 { 142 return of_get_named_gpio_flags(np, propname, index, NULL); 143 } 144 145 /** 146 * of_get_gpio() - Get a GPIO number to use with GPIO API 147 * @np: device node to get GPIO from 148 * @index: index of the GPIO 149 * 150 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 151 * value on the error condition. 152 */ 153 static inline int of_get_gpio(struct device_node *np, int index) 154 { 155 return of_get_gpio_flags(np, index, NULL); 156 } 157 158 #endif /* __LINUX_OF_GPIO_H */ 159