Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
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/err.h>
19#include <linux/gpio.h>
20#include <linux/gpio/consumer.h>
21#include <linux/device.h>
22#include <linux/gfp.h>
23
24static void devm_gpiod_release(struct device *dev, void *res)
25{
26 struct gpio_desc **desc = res;
27
28 gpiod_put(*desc);
29}
30
31static int devm_gpiod_match(struct device *dev, void *res, void *data)
32{
33 struct gpio_desc **this = res, **gpio = data;
34
35 return *this == *gpio;
36}
37
38/**
39 * devm_gpiod_get - Resource-managed gpiod_get()
40 * @dev: GPIO consumer
41 * @con_id: function within the GPIO consumer
42 *
43 * Managed gpiod_get(). GPIO descriptors returned from this function are
44 * automatically disposed on driver detach. See gpiod_get() for detailed
45 * information about behavior and return values.
46 */
47struct gpio_desc *__must_check devm_gpiod_get(struct device *dev,
48 const char *con_id)
49{
50 return devm_gpiod_get_index(dev, con_id, 0);
51}
52EXPORT_SYMBOL(devm_gpiod_get);
53
54/**
55 * devm_gpiod_get_index - Resource-managed gpiod_get_index()
56 * @dev: GPIO consumer
57 * @con_id: function within the GPIO consumer
58 * @idx: index of the GPIO to obtain in the consumer
59 *
60 * Managed gpiod_get_index(). GPIO descriptors returned from this function are
61 * automatically disposed on driver detach. See gpiod_get_index() for detailed
62 * information about behavior and return values.
63 */
64struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
65 const char *con_id,
66 unsigned int idx)
67{
68 struct gpio_desc **dr;
69 struct gpio_desc *desc;
70
71 dr = devres_alloc(devm_gpiod_release, sizeof(struct gpiod_desc *),
72 GFP_KERNEL);
73 if (!dr)
74 return ERR_PTR(-ENOMEM);
75
76 desc = gpiod_get_index(dev, con_id, idx);
77 if (IS_ERR(desc)) {
78 devres_free(dr);
79 return desc;
80 }
81
82 *dr = desc;
83 devres_add(dev, dr);
84
85 return desc;
86}
87EXPORT_SYMBOL(devm_gpiod_get_index);
88
89/**
90 * devm_gpiod_put - Resource-managed gpiod_put()
91 * @desc: GPIO descriptor to dispose of
92 *
93 * Dispose of a GPIO descriptor obtained with devm_gpiod_get() or
94 * devm_gpiod_get_index(). Normally this function will not be called as the GPIO
95 * will be disposed of by the resource management code.
96 */
97void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
98{
99 WARN_ON(devres_release(dev, devm_gpiod_release, devm_gpiod_match,
100 &desc));
101}
102EXPORT_SYMBOL(devm_gpiod_put);
103
104
105
106
107static void devm_gpio_release(struct device *dev, void *res)
108{
109 unsigned *gpio = res;
110
111 gpio_free(*gpio);
112}
113
114static int devm_gpio_match(struct device *dev, void *res, void *data)
115{
116 unsigned *this = res, *gpio = data;
117
118 return *this == *gpio;
119}
120
121/**
122 * devm_gpio_request - request a GPIO for a managed device
123 * @dev: device to request the GPIO for
124 * @gpio: GPIO to allocate
125 * @label: the name of the requested GPIO
126 *
127 * Except for the extra @dev argument, this function takes the
128 * same arguments and performs the same function as
129 * gpio_request(). GPIOs requested with this function will be
130 * automatically freed on driver detach.
131 *
132 * If an GPIO allocated with this function needs to be freed
133 * separately, devm_gpio_free() must be used.
134 */
135
136int devm_gpio_request(struct device *dev, unsigned gpio, const char *label)
137{
138 unsigned *dr;
139 int rc;
140
141 dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
142 if (!dr)
143 return -ENOMEM;
144
145 rc = gpio_request(gpio, label);
146 if (rc) {
147 devres_free(dr);
148 return rc;
149 }
150
151 *dr = gpio;
152 devres_add(dev, dr);
153
154 return 0;
155}
156EXPORT_SYMBOL(devm_gpio_request);
157
158/**
159 * devm_gpio_request_one - request a single GPIO with initial setup
160 * @dev: device to request for
161 * @gpio: the GPIO number
162 * @flags: GPIO configuration as specified by GPIOF_*
163 * @label: a literal description string of this GPIO
164 */
165int devm_gpio_request_one(struct device *dev, unsigned gpio,
166 unsigned long flags, const char *label)
167{
168 unsigned *dr;
169 int rc;
170
171 dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
172 if (!dr)
173 return -ENOMEM;
174
175 rc = gpio_request_one(gpio, flags, label);
176 if (rc) {
177 devres_free(dr);
178 return rc;
179 }
180
181 *dr = gpio;
182 devres_add(dev, dr);
183
184 return 0;
185}
186EXPORT_SYMBOL(devm_gpio_request_one);
187
188/**
189 * devm_gpio_free - free a GPIO
190 * @dev: device to free GPIO for
191 * @gpio: GPIO to free
192 *
193 * Except for the extra @dev argument, this function takes the
194 * same arguments and performs the same function as gpio_free().
195 * This function instead of gpio_free() should be used to manually
196 * free GPIOs allocated with devm_gpio_request().
197 */
198void devm_gpio_free(struct device *dev, unsigned int gpio)
199{
200
201 WARN_ON(devres_release(dev, devm_gpio_release, devm_gpio_match,
202 &gpio));
203}
204EXPORT_SYMBOL(devm_gpio_free);