| 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 | OF_GPIO_SINGLE_ENDED = 0x2, |
| 33 | }; |
| 34 | |
| 35 | #ifdef CONFIG_OF_GPIO |
| 36 | |
| 37 | /* |
| 38 | * OF GPIO chip for memory mapped banks |
| 39 | */ |
| 40 | struct of_mm_gpio_chip { |
| 41 | struct gpio_chip 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 | return container_of(gc, struct of_mm_gpio_chip, gc); |
| 49 | } |
| 50 | |
| 51 | extern int of_get_named_gpio_flags(struct device_node *np, |
| 52 | const char *list_name, int index, enum of_gpio_flags *flags); |
| 53 | |
| 54 | extern int of_mm_gpiochip_add_data(struct device_node *np, |
| 55 | struct of_mm_gpio_chip *mm_gc, |
| 56 | void *data); |
| 57 | static inline int of_mm_gpiochip_add(struct device_node *np, |
| 58 | struct of_mm_gpio_chip *mm_gc) |
| 59 | { |
| 60 | return of_mm_gpiochip_add_data(np, mm_gc, NULL); |
| 61 | } |
| 62 | extern void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc); |
| 63 | |
| 64 | extern int of_gpiochip_add(struct gpio_chip *gc); |
| 65 | extern void of_gpiochip_remove(struct gpio_chip *gc); |
| 66 | extern int of_gpio_simple_xlate(struct gpio_chip *gc, |
| 67 | const struct of_phandle_args *gpiospec, |
| 68 | u32 *flags); |
| 69 | |
| 70 | #else /* CONFIG_OF_GPIO */ |
| 71 | |
| 72 | /* Drivers may not strictly depend on the GPIO support, so let them link. */ |
| 73 | static inline int of_get_named_gpio_flags(struct device_node *np, |
| 74 | const char *list_name, int index, enum of_gpio_flags *flags) |
| 75 | { |
| 76 | if (flags) |
| 77 | *flags = 0; |
| 78 | |
| 79 | return -ENOSYS; |
| 80 | } |
| 81 | |
| 82 | static inline int of_gpio_simple_xlate(struct gpio_chip *gc, |
| 83 | const struct of_phandle_args *gpiospec, |
| 84 | u32 *flags) |
| 85 | { |
| 86 | return -ENOSYS; |
| 87 | } |
| 88 | |
| 89 | static inline int of_gpiochip_add(struct gpio_chip *gc) { return 0; } |
| 90 | static inline void of_gpiochip_remove(struct gpio_chip *gc) { } |
| 91 | |
| 92 | #endif /* CONFIG_OF_GPIO */ |
| 93 | |
| 94 | /** |
| 95 | * of_gpio_named_count() - Count GPIOs for a device |
| 96 | * @np: device node to count GPIOs for |
| 97 | * @propname: property name containing gpio specifier(s) |
| 98 | * |
| 99 | * The function returns the count of GPIOs specified for a node. |
| 100 | * Note that the empty GPIO specifiers count too. Returns either |
| 101 | * Number of gpios defined in property, |
| 102 | * -EINVAL for an incorrectly formed gpios property, or |
| 103 | * -ENOENT for a missing gpios property |
| 104 | * |
| 105 | * Example: |
| 106 | * gpios = <0 |
| 107 | * &gpio1 1 2 |
| 108 | * 0 |
| 109 | * &gpio2 3 4>; |
| 110 | * |
| 111 | * The above example defines four GPIOs, two of which are not specified. |
| 112 | * This function will return '4' |
| 113 | */ |
| 114 | static inline int of_gpio_named_count(struct device_node *np, const char* propname) |
| 115 | { |
| 116 | return of_count_phandle_with_args(np, propname, "#gpio-cells"); |
| 117 | } |
| 118 | |
| 119 | /** |
| 120 | * of_gpio_count() - Count GPIOs for a device |
| 121 | * @np: device node to count GPIOs for |
| 122 | * |
| 123 | * Same as of_gpio_named_count, but hard coded to use the 'gpios' property |
| 124 | */ |
| 125 | static inline int of_gpio_count(struct device_node *np) |
| 126 | { |
| 127 | return of_gpio_named_count(np, "gpios"); |
| 128 | } |
| 129 | |
| 130 | static inline int of_get_gpio_flags(struct device_node *np, int index, |
| 131 | enum of_gpio_flags *flags) |
| 132 | { |
| 133 | return of_get_named_gpio_flags(np, "gpios", index, flags); |
| 134 | } |
| 135 | |
| 136 | /** |
| 137 | * of_get_named_gpio() - Get a GPIO number to use with GPIO API |
| 138 | * @np: device node to get GPIO from |
| 139 | * @propname: Name of property containing gpio specifier(s) |
| 140 | * @index: index of the GPIO |
| 141 | * |
| 142 | * Returns GPIO number to use with Linux generic GPIO API, or one of the errno |
| 143 | * value on the error condition. |
| 144 | */ |
| 145 | static inline int of_get_named_gpio(struct device_node *np, |
| 146 | const char *propname, int index) |
| 147 | { |
| 148 | return of_get_named_gpio_flags(np, propname, index, NULL); |
| 149 | } |
| 150 | |
| 151 | /** |
| 152 | * of_get_gpio() - Get a GPIO number to use with GPIO API |
| 153 | * @np: device node to get GPIO from |
| 154 | * @index: index of the GPIO |
| 155 | * |
| 156 | * Returns GPIO number to use with Linux generic GPIO API, or one of the errno |
| 157 | * value on the error condition. |
| 158 | */ |
| 159 | static inline int of_get_gpio(struct device_node *np, int index) |
| 160 | { |
| 161 | return of_get_gpio_flags(np, index, NULL); |
| 162 | } |
| 163 | |
| 164 | #endif /* __LINUX_OF_GPIO_H */ |