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
devm_gpiod_release(struct device * dev,void * res)24 static void devm_gpiod_release(struct device *dev, void *res)
25 {
26 struct gpio_desc **desc = res;
27
28 gpiod_put(*desc);
29 }
30
devm_gpiod_match(struct device * dev,void * res,void * data)31 static 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 * @flags: optional GPIO initialization flags
43 *
44 * Managed gpiod_get(). GPIO descriptors returned from this function are
45 * automatically disposed on driver detach. See gpiod_get() for detailed
46 * information about behavior and return values.
47 */
__devm_gpiod_get(struct device * dev,const char * con_id,enum gpiod_flags flags)48 struct gpio_desc *__must_check __devm_gpiod_get(struct device *dev,
49 const char *con_id,
50 enum gpiod_flags flags)
51 {
52 return devm_gpiod_get_index(dev, con_id, 0, flags);
53 }
54 EXPORT_SYMBOL(__devm_gpiod_get);
55
56 /**
57 * devm_gpiod_get_optional - Resource-managed gpiod_get_optional()
58 * @dev: GPIO consumer
59 * @con_id: function within the GPIO consumer
60 * @flags: optional GPIO initialization flags
61 *
62 * Managed gpiod_get_optional(). GPIO descriptors returned from this function
63 * are automatically disposed on driver detach. See gpiod_get_optional() for
64 * detailed information about behavior and return values.
65 */
__devm_gpiod_get_optional(struct device * dev,const char * con_id,enum gpiod_flags flags)66 struct gpio_desc *__must_check __devm_gpiod_get_optional(struct device *dev,
67 const char *con_id,
68 enum gpiod_flags flags)
69 {
70 return devm_gpiod_get_index_optional(dev, con_id, 0, flags);
71 }
72 EXPORT_SYMBOL(__devm_gpiod_get_optional);
73
74 /**
75 * devm_gpiod_get_index - Resource-managed gpiod_get_index()
76 * @dev: GPIO consumer
77 * @con_id: function within the GPIO consumer
78 * @idx: index of the GPIO to obtain in the consumer
79 * @flags: optional GPIO initialization flags
80 *
81 * Managed gpiod_get_index(). GPIO descriptors returned from this function are
82 * automatically disposed on driver detach. See gpiod_get_index() for detailed
83 * information about behavior and return values.
84 */
__devm_gpiod_get_index(struct device * dev,const char * con_id,unsigned int idx,enum gpiod_flags flags)85 struct gpio_desc *__must_check __devm_gpiod_get_index(struct device *dev,
86 const char *con_id,
87 unsigned int idx,
88 enum gpiod_flags flags)
89 {
90 struct gpio_desc **dr;
91 struct gpio_desc *desc;
92
93 dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
94 GFP_KERNEL);
95 if (!dr)
96 return ERR_PTR(-ENOMEM);
97
98 desc = gpiod_get_index(dev, con_id, idx, flags);
99 if (IS_ERR(desc)) {
100 devres_free(dr);
101 return desc;
102 }
103
104 *dr = desc;
105 devres_add(dev, dr);
106
107 return desc;
108 }
109 EXPORT_SYMBOL(__devm_gpiod_get_index);
110
111 /**
112 * devm_gpiod_get_index_optional - Resource-managed gpiod_get_index_optional()
113 * @dev: GPIO consumer
114 * @con_id: function within the GPIO consumer
115 * @index: index of the GPIO to obtain in the consumer
116 * @flags: optional GPIO initialization flags
117 *
118 * Managed gpiod_get_index_optional(). GPIO descriptors returned from this
119 * function are automatically disposed on driver detach. See
120 * gpiod_get_index_optional() for detailed information about behavior and
121 * return values.
122 */
__devm_gpiod_get_index_optional(struct device * dev,const char * con_id,unsigned int index,enum gpiod_flags flags)123 struct gpio_desc *__must_check __devm_gpiod_get_index_optional(struct device *dev,
124 const char *con_id,
125 unsigned int index,
126 enum gpiod_flags flags)
127 {
128 struct gpio_desc *desc;
129
130 desc = devm_gpiod_get_index(dev, con_id, index, flags);
131 if (IS_ERR(desc)) {
132 if (PTR_ERR(desc) == -ENOENT)
133 return NULL;
134 }
135
136 return desc;
137 }
138 EXPORT_SYMBOL(__devm_gpiod_get_index_optional);
139
140 /**
141 * devm_gpiod_put - Resource-managed gpiod_put()
142 * @desc: GPIO descriptor to dispose of
143 *
144 * Dispose of a GPIO descriptor obtained with devm_gpiod_get() or
145 * devm_gpiod_get_index(). Normally this function will not be called as the GPIO
146 * will be disposed of by the resource management code.
147 */
devm_gpiod_put(struct device * dev,struct gpio_desc * desc)148 void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)
149 {
150 WARN_ON(devres_release(dev, devm_gpiod_release, devm_gpiod_match,
151 &desc));
152 }
153 EXPORT_SYMBOL(devm_gpiod_put);
154
155
156
157
devm_gpio_release(struct device * dev,void * res)158 static void devm_gpio_release(struct device *dev, void *res)
159 {
160 unsigned *gpio = res;
161
162 gpio_free(*gpio);
163 }
164
devm_gpio_match(struct device * dev,void * res,void * data)165 static int devm_gpio_match(struct device *dev, void *res, void *data)
166 {
167 unsigned *this = res, *gpio = data;
168
169 return *this == *gpio;
170 }
171
172 /**
173 * devm_gpio_request - request a GPIO for a managed device
174 * @dev: device to request the GPIO for
175 * @gpio: GPIO to allocate
176 * @label: the name of the requested GPIO
177 *
178 * Except for the extra @dev argument, this function takes the
179 * same arguments and performs the same function as
180 * gpio_request(). GPIOs requested with this function will be
181 * automatically freed on driver detach.
182 *
183 * If an GPIO allocated with this function needs to be freed
184 * separately, devm_gpio_free() must be used.
185 */
186
devm_gpio_request(struct device * dev,unsigned gpio,const char * label)187 int devm_gpio_request(struct device *dev, unsigned gpio, const char *label)
188 {
189 unsigned *dr;
190 int rc;
191
192 dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
193 if (!dr)
194 return -ENOMEM;
195
196 rc = gpio_request(gpio, label);
197 if (rc) {
198 devres_free(dr);
199 return rc;
200 }
201
202 *dr = gpio;
203 devres_add(dev, dr);
204
205 return 0;
206 }
207 EXPORT_SYMBOL(devm_gpio_request);
208
209 /**
210 * devm_gpio_request_one - request a single GPIO with initial setup
211 * @dev: device to request for
212 * @gpio: the GPIO number
213 * @flags: GPIO configuration as specified by GPIOF_*
214 * @label: a literal description string of this GPIO
215 */
devm_gpio_request_one(struct device * dev,unsigned gpio,unsigned long flags,const char * label)216 int devm_gpio_request_one(struct device *dev, unsigned gpio,
217 unsigned long flags, const char *label)
218 {
219 unsigned *dr;
220 int rc;
221
222 dr = devres_alloc(devm_gpio_release, sizeof(unsigned), GFP_KERNEL);
223 if (!dr)
224 return -ENOMEM;
225
226 rc = gpio_request_one(gpio, flags, label);
227 if (rc) {
228 devres_free(dr);
229 return rc;
230 }
231
232 *dr = gpio;
233 devres_add(dev, dr);
234
235 return 0;
236 }
237 EXPORT_SYMBOL(devm_gpio_request_one);
238
239 /**
240 * devm_gpio_free - free a GPIO
241 * @dev: device to free GPIO for
242 * @gpio: GPIO to free
243 *
244 * Except for the extra @dev argument, this function takes the
245 * same arguments and performs the same function as gpio_free().
246 * This function instead of gpio_free() should be used to manually
247 * free GPIOs allocated with devm_gpio_request().
248 */
devm_gpio_free(struct device * dev,unsigned int gpio)249 void devm_gpio_free(struct device *dev, unsigned int gpio)
250 {
251
252 WARN_ON(devres_release(dev, devm_gpio_release, devm_gpio_match,
253 &gpio));
254 }
255 EXPORT_SYMBOL(devm_gpio_free);
256