Commit | Line | Data |
---|---|---|
1a0703ed JC |
1 | /* |
2 | * drivers/gpio/devres.c - managed gpio resources | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 | |
6 | * as published by the Free Software Foundation. | |
7 | * | |
8 | * You should have received a copy of the GNU General Public License | |
9 | * along with this program; if not, write to the Free Software | |
10 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
11 | * | |
12 | * This file is based on kernel/irq/devres.c | |
13 | * | |
14 | * Copyright (c) 2011 John Crispin <blogic@openwrt.org> | |
15 | */ | |
16 | ||
17 | #include <linux/module.h> | |
18 | #include <linux/gpio.h> | |
19 | #include <linux/device.h> | |
20 | #include <linux/gfp.h> | |
21 | ||
22 | static void devm_gpio_release(struct device *dev, void *res) | |
23 | { | |
24 | unsigned *gpio = res; | |
25 | ||
26 | gpio_free(*gpio); | |
27 | } | |
28 | ||
29 | static int devm_gpio_match(struct device *dev, void *res, void *data) | |
30 | { | |
31 | unsigned *this = res, *gpio = data; | |
32 | ||
33 | return *this == *gpio; | |
34 | } | |
35 | ||
36 | /** | |
37 | * devm_gpio_request - request a gpio for a managed device | |
38 | * @dev: device to request the gpio for | |
39 | * @gpio: gpio to allocate | |
40 | * @label: the name of the requested gpio | |
41 | * | |
42 | * Except for the extra @dev argument, this function takes the | |
43 | * same arguments and performs the same function as | |
44 | * gpio_request(). GPIOs requested with this function will be | |
45 | * automatically freed on driver detach. | |
46 | * | |
47 | * If an GPIO allocated with this function needs to be freed | |
48 | * separately, devm_gpio_free() must be used. | |
49 | */ | |
50 | ||
51 | int devm_gpio_request(struct device *dev, unsigned gpio, const char *label) | |
52 | { | |
53 | unsigned *dr; | |
54 | int rc; | |
55 | ||
56 | dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL); | |
57 | if (!dr) | |
58 | return -ENOMEM; | |
59 | ||
60 | rc = gpio_request(gpio, label); | |
61 | if (rc) { | |
62 | devres_free(dr); | |
63 | return rc; | |
64 | } | |
65 | ||
66 | *dr = gpio; | |
67 | devres_add(dev, dr); | |
68 | ||
69 | return 0; | |
70 | } | |
71 | EXPORT_SYMBOL(devm_gpio_request); | |
72 | ||
73 | /** | |
74 | * devm_gpio_free - free an interrupt | |
75 | * @dev: device to free gpio for | |
76 | * @gpio: gpio to free | |
77 | * | |
78 | * Except for the extra @dev argument, this function takes the | |
79 | * same arguments and performs the same function as gpio_free(). | |
80 | * This function instead of gpio_free() should be used to manually | |
81 | * free GPIOs allocated with devm_gpio_request(). | |
82 | */ | |
83 | void devm_gpio_free(struct device *dev, unsigned int gpio) | |
84 | { | |
85 | ||
86 | WARN_ON(devres_destroy(dev, devm_gpio_release, devm_gpio_match, | |
87 | &gpio)); | |
88 | gpio_free(gpio); | |
89 | } | |
90 | EXPORT_SYMBOL(devm_gpio_free); |