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 * 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_gpio_flags(struct device_node *np, int index, 50 enum of_gpio_flags *flags); 51 extern unsigned int of_gpio_count(struct device_node *np); 52 53 extern int of_mm_gpiochip_add(struct device_node *np, 54 struct of_mm_gpio_chip *mm_gc); 55 56 extern void of_gpiochip_add(struct gpio_chip *gc); 57 extern void of_gpiochip_remove(struct gpio_chip *gc); 58 extern struct gpio_chip *of_node_to_gpiochip(struct device_node *np); 59 60 #else /* CONFIG_OF_GPIO */ 61 62 /* Drivers may not strictly depend on the GPIO support, so let them link. */ 63 static inline int of_get_gpio_flags(struct device_node *np, int index, 64 enum of_gpio_flags *flags) 65 { 66 return -ENOSYS; 67 } 68 69 static inline unsigned int of_gpio_count(struct device_node *np) 70 { 71 return 0; 72 } 73 74 static inline void of_gpiochip_add(struct gpio_chip *gc) { } 75 static inline void of_gpiochip_remove(struct gpio_chip *gc) { } 76 77 #endif /* CONFIG_OF_GPIO */ 78 79 /** 80 * of_get_gpio - Get a GPIO number to use with GPIO API 81 * @np: device node to get GPIO from 82 * @index: index of the GPIO 83 * 84 * Returns GPIO number to use with Linux generic GPIO API, or one of the errno 85 * value on the error condition. 86 */ 87 static inline int of_get_gpio(struct device_node *np, int index) 88 { 89 return of_get_gpio_flags(np, index, NULL); 90 } 91 92 #endif /* __LINUX_OF_GPIO_H */ 93