blob: 9e9947cb86a3d4fe29bb018987176275d4476e2c [file] [log] [blame]
John Crispin1a0703e2011-12-20 21:40:21 +01001/*
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
22static void devm_gpio_release(struct device *dev, void *res)
23{
24 unsigned *gpio = res;
25
26 gpio_free(*gpio);
27}
28
29static 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
51int 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}
71EXPORT_SYMBOL(devm_gpio_request);
72
73/**
Mark Brown09d71ff2012-05-02 12:46:46 +010074 * devm_gpio_request_one - request a single GPIO with initial setup
75 * @dev: device to request for
76 * @gpio: the GPIO number
77 * @flags: GPIO configuration as specified by GPIOF_*
78 * @label: a literal description string of this GPIO
79 */
80int devm_gpio_request_one(struct device *dev, unsigned gpio,
81 unsigned long flags, const char *label)
82{
83 unsigned *dr;
84 int rc;
85
86 dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
87 if (!dr)
88 return -ENOMEM;
89
90 rc = gpio_request_one(gpio, flags, label);
91 if (rc) {
92 devres_free(dr);
93 return rc;
94 }
95
96 *dr = gpio;
97 devres_add(dev, dr);
98
99 return 0;
100}
101
102/**
John Crispin1a0703e2011-12-20 21:40:21 +0100103 * devm_gpio_free - free an interrupt
104 * @dev: device to free gpio for
105 * @gpio: gpio to free
106 *
107 * Except for the extra @dev argument, this function takes the
108 * same arguments and performs the same function as gpio_free().
109 * This function instead of gpio_free() should be used to manually
110 * free GPIOs allocated with devm_gpio_request().
111 */
112void devm_gpio_free(struct device *dev, unsigned int gpio)
113{
114
Mark Browna85990b2012-05-03 18:15:14 +0100115 WARN_ON(devres_release(dev, devm_gpio_release, devm_gpio_match,
John Crispin1a0703e2011-12-20 21:40:21 +0100116 &gpio));
John Crispin1a0703e2011-12-20 21:40:21 +0100117}
118EXPORT_SYMBOL(devm_gpio_free);