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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> | |
3c2c628f | 18 | #include <linux/err.h> |
1a0703ed | 19 | #include <linux/gpio.h> |
3c2c628f | 20 | #include <linux/gpio/consumer.h> |
1a0703ed JC |
21 | #include <linux/device.h> |
22 | #include <linux/gfp.h> | |
23 | ||
bae48da2 AC |
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 | ||
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 | * | |
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 | */ | |
47 | struct 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 | } | |
52 | EXPORT_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 | */ | |
64 | struct 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 | ||
5fcdb9dc | 85 | return desc; |
bae48da2 AC |
86 | } |
87 | EXPORT_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 | */ | |
97 | void 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 | } | |
102 | EXPORT_SYMBOL(devm_gpiod_put); | |
103 | ||
104 | ||
105 | ||
106 | ||
1a0703ed JC |
107 | static void devm_gpio_release(struct device *dev, void *res) |
108 | { | |
109 | unsigned *gpio = res; | |
110 | ||
111 | gpio_free(*gpio); | |
112 | } | |
113 | ||
114 | static 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 | /** | |
713b7ef8 WS |
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 | |
1a0703ed JC |
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 | ||
136 | int 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 | } | |
156 | EXPORT_SYMBOL(devm_gpio_request); | |
157 | ||
09d71ff1 MB |
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 | */ | |
165 | int 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 | } | |
3996bfc7 | 186 | EXPORT_SYMBOL(devm_gpio_request_one); |
09d71ff1 | 187 | |
1a0703ed | 188 | /** |
713b7ef8 WS |
189 | * devm_gpio_free - free a GPIO |
190 | * @dev: device to free GPIO for | |
191 | * @gpio: GPIO to free | |
1a0703ed JC |
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 | */ | |
198 | void devm_gpio_free(struct device *dev, unsigned int gpio) | |
199 | { | |
200 | ||
a85990b3 | 201 | WARN_ON(devres_release(dev, devm_gpio_release, devm_gpio_match, |
1a0703ed | 202 | &gpio)); |
1a0703ed JC |
203 | } |
204 | EXPORT_SYMBOL(devm_gpio_free); |