xref: /openbmc/linux/include/linux/of_gpio.h (revision 8fa5723aa7e053d498336b48448b292fc2e0458b)
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/errno.h>
18 #include <linux/gpio.h>
19 
20 #ifdef CONFIG_OF_GPIO
21 
22 /*
23  * Generic OF GPIO chip
24  */
25 struct of_gpio_chip {
26 	struct gpio_chip gc;
27 	int gpio_cells;
28 	int (*xlate)(struct of_gpio_chip *of_gc, struct device_node *np,
29 		     const void *gpio_spec);
30 };
31 
32 static inline struct of_gpio_chip *to_of_gpio_chip(struct gpio_chip *gc)
33 {
34 	return container_of(gc, struct of_gpio_chip, gc);
35 }
36 
37 /*
38  * OF GPIO chip for memory mapped banks
39  */
40 struct of_mm_gpio_chip {
41 	struct of_gpio_chip of_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 	struct of_gpio_chip *of_gc = to_of_gpio_chip(gc);
49 
50 	return container_of(of_gc, struct of_mm_gpio_chip, of_gc);
51 }
52 
53 extern int of_get_gpio(struct device_node *np, int index);
54 extern int of_mm_gpiochip_add(struct device_node *np,
55 			      struct of_mm_gpio_chip *mm_gc);
56 extern int of_gpio_simple_xlate(struct of_gpio_chip *of_gc,
57 				struct device_node *np,
58 				const void *gpio_spec);
59 #else
60 
61 /* Drivers may not strictly depend on the GPIO support, so let them link. */
62 static inline int of_get_gpio(struct device_node *np, int index)
63 {
64 	return -ENOSYS;
65 }
66 
67 #endif /* CONFIG_OF_GPIO */
68 
69 #endif /* __LINUX_OF_GPIO_H */
70