Linux kernel mirror (for testing)
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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_optional - Resource-managed gpiod_get_optional()
56 * @dev: GPIO consumer
57 * @con_id: function within the GPIO consumer
58 *
59 * Managed gpiod_get_optional(). GPIO descriptors returned from this function
60 * are automatically disposed on driver detach. See gpiod_get_optional() for
61 * detailed information about behavior and return values.
62 */
63struct gpio_desc *__must_check devm_gpiod_get_optional(struct device *dev,
64 const char *con_id)
65{
66 return devm_gpiod_get_index_optional(dev, con_id, 0);
67}
68EXPORT_SYMBOL(devm_gpiod_get_optional);
69
70/**
71 * devm_gpiod_get_index - Resource-managed gpiod_get_index()
72 * @dev: GPIO consumer
73 * @con_id: function within the GPIO consumer
74 * @idx: index of the GPIO to obtain in the consumer
75 *
76 * Managed gpiod_get_index(). GPIO descriptors returned from this function are
77 * automatically disposed on driver detach. See gpiod_get_index() for detailed
78 * information about behavior and return values.
79 */
80struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
81 const char *con_id,
82 unsigned int idx)
83{
84 struct gpio_desc **dr;
85 struct gpio_desc *desc;
86
87 dr = devres_alloc(devm_gpiod_release, sizeof(struct gpiod_desc *),
88 GFP_KERNEL);
89 if (!dr)
90 return ERR_PTR(-ENOMEM);
91
92 desc = gpiod_get_index(dev, con_id, idx);
93 if (IS_ERR(desc)) {
94 devres_free(dr);
95 return desc;
96 }
97
98 *dr = desc;
99 devres_add(dev, dr);
100
101 return desc;
102}
103EXPORT_SYMBOL(devm_gpiod_get_index);
104
105/**
106 * devm_gpiod_get_index_optional - Resource-managed gpiod_get_index_optional()
107 * @dev: GPIO consumer
108 * @con_id: function within the GPIO consumer
109 * @index: index of the GPIO to obtain in the consumer
110 *
111 * Managed gpiod_get_index_optional(). GPIO descriptors returned from this
112 * function are automatically disposed on driver detach. See
113 * gpiod_get_index_optional() for detailed information about behavior and
114 * return values.
115 */
116struct gpio_desc *__must_check devm_gpiod_get_index_optional(struct device *dev,
117 const char *con_id,
118 unsigned int index)
119{
120 struct gpio_desc *desc;
121
122 desc = devm_gpiod_get_index(dev, con_id, index);
123 if (IS_ERR(desc)) {
124 if (PTR_ERR(desc) == -ENOENT)
125 return NULL;
126 }
127
128 return desc;
129}
130EXPORT_SYMBOL(devm_gpiod_get_index_optional);
131
132/**
133 * devm_gpiod_put - Resource-managed gpiod_put()
134 * @desc: GPIO descriptor to dispose of
135 *
136 * Dispose of a GPIO descriptor obtained with devm_gpiod_get() or
137 * devm_gpiod_get_index(). Normally this function will not be called as the GPIO
138 * will be disposed of by the resource management code.
139 */
140void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
141{
142 WARN_ON(devres_release(dev, devm_gpiod_release, devm_gpiod_match,
143 &desc));
144}
145EXPORT_SYMBOL(devm_gpiod_put);
146
147
148
149
150static void devm_gpio_release(struct device *dev, void *res)
151{
152 unsigned *gpio = res;
153
154 gpio_free(*gpio);
155}
156
157static int devm_gpio_match(struct device *dev, void *res, void *data)
158{
159 unsigned *this = res, *gpio = data;
160
161 return *this == *gpio;
162}
163
164/**
165 * devm_gpio_request - request a GPIO for a managed device
166 * @dev: device to request the GPIO for
167 * @gpio: GPIO to allocate
168 * @label: the name of the requested GPIO
169 *
170 * Except for the extra @dev argument, this function takes the
171 * same arguments and performs the same function as
172 * gpio_request(). GPIOs requested with this function will be
173 * automatically freed on driver detach.
174 *
175 * If an GPIO allocated with this function needs to be freed
176 * separately, devm_gpio_free() must be used.
177 */
178
179int devm_gpio_request(struct device *dev, unsigned gpio, const char *label)
180{
181 unsigned *dr;
182 int rc;
183
184 dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
185 if (!dr)
186 return -ENOMEM;
187
188 rc = gpio_request(gpio, label);
189 if (rc) {
190 devres_free(dr);
191 return rc;
192 }
193
194 *dr = gpio;
195 devres_add(dev, dr);
196
197 return 0;
198}
199EXPORT_SYMBOL(devm_gpio_request);
200
201/**
202 * devm_gpio_request_one - request a single GPIO with initial setup
203 * @dev: device to request for
204 * @gpio: the GPIO number
205 * @flags: GPIO configuration as specified by GPIOF_*
206 * @label: a literal description string of this GPIO
207 */
208int devm_gpio_request_one(struct device *dev, unsigned gpio,
209 unsigned long flags, const char *label)
210{
211 unsigned *dr;
212 int rc;
213
214 dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
215 if (!dr)
216 return -ENOMEM;
217
218 rc = gpio_request_one(gpio, flags, label);
219 if (rc) {
220 devres_free(dr);
221 return rc;
222 }
223
224 *dr = gpio;
225 devres_add(dev, dr);
226
227 return 0;
228}
229EXPORT_SYMBOL(devm_gpio_request_one);
230
231/**
232 * devm_gpio_free - free a GPIO
233 * @dev: device to free GPIO for
234 * @gpio: GPIO to free
235 *
236 * Except for the extra @dev argument, this function takes the
237 * same arguments and performs the same function as gpio_free().
238 * This function instead of gpio_free() should be used to manually
239 * free GPIOs allocated with devm_gpio_request().
240 */
241void devm_gpio_free(struct device *dev, unsigned int gpio)
242{
243
244 WARN_ON(devres_release(dev, devm_gpio_release, devm_gpio_match,
245 &gpio));
246}
247EXPORT_SYMBOL(devm_gpio_free);