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1/*
2 * LED Class Core
3 *
4 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
5 * Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/init.h>
15#include <linux/list.h>
16#include <linux/spinlock.h>
17#include <linux/device.h>
18#include <linux/sysdev.h>
19#include <linux/timer.h>
20#include <linux/err.h>
21#include <linux/ctype.h>
22#include <linux/leds.h>
23#include "leds.h"
24
25static struct class *leds_class;
26
27static void led_update_brightness(struct led_classdev *led_cdev)
28{
29 if (led_cdev->brightness_get)
30 led_cdev->brightness = led_cdev->brightness_get(led_cdev);
31}
32
33static ssize_t led_brightness_show(struct device *dev,
34 struct device_attribute *attr, char *buf)
35{
36 struct led_classdev *led_cdev = dev_get_drvdata(dev);
37
38 /* no lock needed for this */
39 led_update_brightness(led_cdev);
40
41 return sprintf(buf, "%u\n", led_cdev->brightness);
42}
43
44static ssize_t led_brightness_store(struct device *dev,
45 struct device_attribute *attr, const char *buf, size_t size)
46{
47 struct led_classdev *led_cdev = dev_get_drvdata(dev);
48 ssize_t ret = -EINVAL;
49 char *after;
50 unsigned long state = simple_strtoul(buf, &after, 10);
51 size_t count = after - buf;
52
53 if (isspace(*after))
54 count++;
55
56 if (count == size) {
57 ret = count;
58
59 if (state == LED_OFF)
60 led_trigger_remove(led_cdev);
61 led_set_brightness(led_cdev, state);
62 }
63
64 return ret;
65}
66
67static ssize_t led_max_brightness_show(struct device *dev,
68 struct device_attribute *attr, char *buf)
69{
70 struct led_classdev *led_cdev = dev_get_drvdata(dev);
71
72 return sprintf(buf, "%u\n", led_cdev->max_brightness);
73}
74
75static struct device_attribute led_class_attrs[] = {
76 __ATTR(brightness, 0644, led_brightness_show, led_brightness_store),
77 __ATTR(max_brightness, 0444, led_max_brightness_show, NULL),
78#ifdef CONFIG_LEDS_TRIGGERS
79 __ATTR(trigger, 0644, led_trigger_show, led_trigger_store),
80#endif
81 __ATTR_NULL,
82};
83
84static void led_timer_function(unsigned long data)
85{
86 struct led_classdev *led_cdev = (void *)data;
87 unsigned long brightness;
88 unsigned long delay;
89
90 if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) {
91 led_set_brightness(led_cdev, LED_OFF);
92 return;
93 }
94
95 brightness = led_get_brightness(led_cdev);
96 if (!brightness) {
97 /* Time to switch the LED on. */
98 brightness = led_cdev->blink_brightness;
99 delay = led_cdev->blink_delay_on;
100 } else {
101 /* Store the current brightness value to be able
102 * to restore it when the delay_off period is over.
103 */
104 led_cdev->blink_brightness = brightness;
105 brightness = LED_OFF;
106 delay = led_cdev->blink_delay_off;
107 }
108
109 led_set_brightness(led_cdev, brightness);
110
111 mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
112}
113
114static void led_stop_software_blink(struct led_classdev *led_cdev)
115{
116 /* deactivate previous settings */
117 del_timer_sync(&led_cdev->blink_timer);
118 led_cdev->blink_delay_on = 0;
119 led_cdev->blink_delay_off = 0;
120}
121
122static void led_set_software_blink(struct led_classdev *led_cdev,
123 unsigned long delay_on,
124 unsigned long delay_off)
125{
126 int current_brightness;
127
128 current_brightness = led_get_brightness(led_cdev);
129 if (current_brightness)
130 led_cdev->blink_brightness = current_brightness;
131 if (!led_cdev->blink_brightness)
132 led_cdev->blink_brightness = led_cdev->max_brightness;
133
134 if (led_get_trigger_data(led_cdev) &&
135 delay_on == led_cdev->blink_delay_on &&
136 delay_off == led_cdev->blink_delay_off)
137 return;
138
139 led_stop_software_blink(led_cdev);
140
141 led_cdev->blink_delay_on = delay_on;
142 led_cdev->blink_delay_off = delay_off;
143
144 /* never on - don't blink */
145 if (!delay_on)
146 return;
147
148 /* never off - just set to brightness */
149 if (!delay_off) {
150 led_set_brightness(led_cdev, led_cdev->blink_brightness);
151 return;
152 }
153
154 mod_timer(&led_cdev->blink_timer, jiffies + 1);
155}
156
157
158/**
159 * led_classdev_suspend - suspend an led_classdev.
160 * @led_cdev: the led_classdev to suspend.
161 */
162void led_classdev_suspend(struct led_classdev *led_cdev)
163{
164 led_cdev->flags |= LED_SUSPENDED;
165 led_cdev->brightness_set(led_cdev, 0);
166}
167EXPORT_SYMBOL_GPL(led_classdev_suspend);
168
169/**
170 * led_classdev_resume - resume an led_classdev.
171 * @led_cdev: the led_classdev to resume.
172 */
173void led_classdev_resume(struct led_classdev *led_cdev)
174{
175 led_cdev->brightness_set(led_cdev, led_cdev->brightness);
176 led_cdev->flags &= ~LED_SUSPENDED;
177}
178EXPORT_SYMBOL_GPL(led_classdev_resume);
179
180static int led_suspend(struct device *dev, pm_message_t state)
181{
182 struct led_classdev *led_cdev = dev_get_drvdata(dev);
183
184 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
185 led_classdev_suspend(led_cdev);
186
187 return 0;
188}
189
190static int led_resume(struct device *dev)
191{
192 struct led_classdev *led_cdev = dev_get_drvdata(dev);
193
194 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
195 led_classdev_resume(led_cdev);
196
197 return 0;
198}
199
200/**
201 * led_classdev_register - register a new object of led_classdev class.
202 * @parent: The device to register.
203 * @led_cdev: the led_classdev structure for this device.
204 */
205int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
206{
207 led_cdev->dev = device_create(leds_class, parent, 0, led_cdev,
208 "%s", led_cdev->name);
209 if (IS_ERR(led_cdev->dev))
210 return PTR_ERR(led_cdev->dev);
211
212#ifdef CONFIG_LEDS_TRIGGERS
213 init_rwsem(&led_cdev->trigger_lock);
214#endif
215 /* add to the list of leds */
216 down_write(&leds_list_lock);
217 list_add_tail(&led_cdev->node, &leds_list);
218 up_write(&leds_list_lock);
219
220 if (!led_cdev->max_brightness)
221 led_cdev->max_brightness = LED_FULL;
222
223 led_update_brightness(led_cdev);
224
225 init_timer(&led_cdev->blink_timer);
226 led_cdev->blink_timer.function = led_timer_function;
227 led_cdev->blink_timer.data = (unsigned long)led_cdev;
228
229#ifdef CONFIG_LEDS_TRIGGERS
230 led_trigger_set_default(led_cdev);
231#endif
232
233 printk(KERN_DEBUG "Registered led device: %s\n",
234 led_cdev->name);
235
236 return 0;
237}
238EXPORT_SYMBOL_GPL(led_classdev_register);
239
240/**
241 * led_classdev_unregister - unregisters a object of led_properties class.
242 * @led_cdev: the led device to unregister
243 *
244 * Unregisters a previously registered via led_classdev_register object.
245 */
246void led_classdev_unregister(struct led_classdev *led_cdev)
247{
248#ifdef CONFIG_LEDS_TRIGGERS
249 down_write(&led_cdev->trigger_lock);
250 if (led_cdev->trigger)
251 led_trigger_set(led_cdev, NULL);
252 up_write(&led_cdev->trigger_lock);
253#endif
254
255 /* Stop blinking */
256 led_brightness_set(led_cdev, LED_OFF);
257
258 device_unregister(led_cdev->dev);
259
260 down_write(&leds_list_lock);
261 list_del(&led_cdev->node);
262 up_write(&leds_list_lock);
263}
264EXPORT_SYMBOL_GPL(led_classdev_unregister);
265
266void led_blink_set(struct led_classdev *led_cdev,
267 unsigned long *delay_on,
268 unsigned long *delay_off)
269{
270 if (led_cdev->blink_set &&
271 !led_cdev->blink_set(led_cdev, delay_on, delay_off))
272 return;
273
274 /* blink with 1 Hz as default if nothing specified */
275 if (!*delay_on && !*delay_off)
276 *delay_on = *delay_off = 500;
277
278 led_set_software_blink(led_cdev, *delay_on, *delay_off);
279}
280EXPORT_SYMBOL(led_blink_set);
281
282void led_brightness_set(struct led_classdev *led_cdev,
283 enum led_brightness brightness)
284{
285 led_stop_software_blink(led_cdev);
286 led_cdev->brightness_set(led_cdev, brightness);
287}
288EXPORT_SYMBOL(led_brightness_set);
289
290static int __init leds_init(void)
291{
292 leds_class = class_create(THIS_MODULE, "leds");
293 if (IS_ERR(leds_class))
294 return PTR_ERR(leds_class);
295 leds_class->suspend = led_suspend;
296 leds_class->resume = led_resume;
297 leds_class->dev_attrs = led_class_attrs;
298 return 0;
299}
300
301static void __exit leds_exit(void)
302{
303 class_destroy(leds_class);
304}
305
306subsys_initcall(leds_init);
307module_exit(leds_exit);
308
309MODULE_AUTHOR("John Lenz, Richard Purdie");
310MODULE_LICENSE("GPL");
311MODULE_DESCRIPTION("LED Class Interface");
1/*
2 * LED Class Core
3 *
4 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
5 * Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/ctype.h>
13#include <linux/device.h>
14#include <linux/err.h>
15#include <linux/init.h>
16#include <linux/kernel.h>
17#include <linux/leds.h>
18#include <linux/list.h>
19#include <linux/module.h>
20#include <linux/slab.h>
21#include <linux/spinlock.h>
22#include <linux/timer.h>
23#include "leds.h"
24
25static struct class *leds_class;
26
27static ssize_t brightness_show(struct device *dev,
28 struct device_attribute *attr, char *buf)
29{
30 struct led_classdev *led_cdev = dev_get_drvdata(dev);
31
32 /* no lock needed for this */
33 led_update_brightness(led_cdev);
34
35 return sprintf(buf, "%u\n", led_cdev->brightness);
36}
37
38static ssize_t brightness_store(struct device *dev,
39 struct device_attribute *attr, const char *buf, size_t size)
40{
41 struct led_classdev *led_cdev = dev_get_drvdata(dev);
42 unsigned long state;
43 ssize_t ret;
44
45 mutex_lock(&led_cdev->led_access);
46
47 if (led_sysfs_is_disabled(led_cdev)) {
48 ret = -EBUSY;
49 goto unlock;
50 }
51
52 ret = kstrtoul(buf, 10, &state);
53 if (ret)
54 goto unlock;
55
56 if (state == LED_OFF)
57 led_trigger_remove(led_cdev);
58 led_set_brightness(led_cdev, state);
59
60 ret = size;
61unlock:
62 mutex_unlock(&led_cdev->led_access);
63 return ret;
64}
65static DEVICE_ATTR_RW(brightness);
66
67static ssize_t max_brightness_show(struct device *dev,
68 struct device_attribute *attr, char *buf)
69{
70 struct led_classdev *led_cdev = dev_get_drvdata(dev);
71
72 return sprintf(buf, "%u\n", led_cdev->max_brightness);
73}
74static DEVICE_ATTR_RO(max_brightness);
75
76#ifdef CONFIG_LEDS_TRIGGERS
77static DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store);
78static struct attribute *led_trigger_attrs[] = {
79 &dev_attr_trigger.attr,
80 NULL,
81};
82static const struct attribute_group led_trigger_group = {
83 .attrs = led_trigger_attrs,
84};
85#endif
86
87static struct attribute *led_class_attrs[] = {
88 &dev_attr_brightness.attr,
89 &dev_attr_max_brightness.attr,
90 NULL,
91};
92
93static const struct attribute_group led_group = {
94 .attrs = led_class_attrs,
95};
96
97static const struct attribute_group *led_groups[] = {
98 &led_group,
99#ifdef CONFIG_LEDS_TRIGGERS
100 &led_trigger_group,
101#endif
102 NULL,
103};
104
105/**
106 * led_classdev_suspend - suspend an led_classdev.
107 * @led_cdev: the led_classdev to suspend.
108 */
109void led_classdev_suspend(struct led_classdev *led_cdev)
110{
111 led_cdev->flags |= LED_SUSPENDED;
112 led_set_brightness_nopm(led_cdev, 0);
113}
114EXPORT_SYMBOL_GPL(led_classdev_suspend);
115
116/**
117 * led_classdev_resume - resume an led_classdev.
118 * @led_cdev: the led_classdev to resume.
119 */
120void led_classdev_resume(struct led_classdev *led_cdev)
121{
122 led_set_brightness_nopm(led_cdev, led_cdev->brightness);
123
124 if (led_cdev->flash_resume)
125 led_cdev->flash_resume(led_cdev);
126
127 led_cdev->flags &= ~LED_SUSPENDED;
128}
129EXPORT_SYMBOL_GPL(led_classdev_resume);
130
131#ifdef CONFIG_PM_SLEEP
132static int led_suspend(struct device *dev)
133{
134 struct led_classdev *led_cdev = dev_get_drvdata(dev);
135
136 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
137 led_classdev_suspend(led_cdev);
138
139 return 0;
140}
141
142static int led_resume(struct device *dev)
143{
144 struct led_classdev *led_cdev = dev_get_drvdata(dev);
145
146 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
147 led_classdev_resume(led_cdev);
148
149 return 0;
150}
151#endif
152
153static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
154
155static int match_name(struct device *dev, const void *data)
156{
157 if (!dev_name(dev))
158 return 0;
159 return !strcmp(dev_name(dev), (char *)data);
160}
161
162static int led_classdev_next_name(const char *init_name, char *name,
163 size_t len)
164{
165 unsigned int i = 0;
166 int ret = 0;
167 struct device *dev;
168
169 strlcpy(name, init_name, len);
170
171 while ((ret < len) &&
172 (dev = class_find_device(leds_class, NULL, name, match_name))) {
173 put_device(dev);
174 ret = snprintf(name, len, "%s_%u", init_name, ++i);
175 }
176
177 if (ret >= len)
178 return -ENOMEM;
179
180 return i;
181}
182
183/**
184 * led_classdev_register - register a new object of led_classdev class.
185 * @parent: The device to register.
186 * @led_cdev: the led_classdev structure for this device.
187 */
188int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
189{
190 char name[64];
191 int ret;
192
193 ret = led_classdev_next_name(led_cdev->name, name, sizeof(name));
194 if (ret < 0)
195 return ret;
196
197 led_cdev->dev = device_create_with_groups(leds_class, parent, 0,
198 led_cdev, led_cdev->groups, "%s", name);
199 if (IS_ERR(led_cdev->dev))
200 return PTR_ERR(led_cdev->dev);
201
202 if (ret)
203 dev_warn(parent, "Led %s renamed to %s due to name collision",
204 led_cdev->name, dev_name(led_cdev->dev));
205
206#ifdef CONFIG_LEDS_TRIGGERS
207 init_rwsem(&led_cdev->trigger_lock);
208#endif
209 mutex_init(&led_cdev->led_access);
210 /* add to the list of leds */
211 down_write(&leds_list_lock);
212 list_add_tail(&led_cdev->node, &leds_list);
213 up_write(&leds_list_lock);
214
215 if (!led_cdev->max_brightness)
216 led_cdev->max_brightness = LED_FULL;
217
218 led_update_brightness(led_cdev);
219
220 led_init_core(led_cdev);
221
222#ifdef CONFIG_LEDS_TRIGGERS
223 led_trigger_set_default(led_cdev);
224#endif
225
226 dev_dbg(parent, "Registered led device: %s\n",
227 led_cdev->name);
228
229 return 0;
230}
231EXPORT_SYMBOL_GPL(led_classdev_register);
232
233/**
234 * led_classdev_unregister - unregisters a object of led_properties class.
235 * @led_cdev: the led device to unregister
236 *
237 * Unregisters a previously registered via led_classdev_register object.
238 */
239void led_classdev_unregister(struct led_classdev *led_cdev)
240{
241#ifdef CONFIG_LEDS_TRIGGERS
242 down_write(&led_cdev->trigger_lock);
243 if (led_cdev->trigger)
244 led_trigger_set(led_cdev, NULL);
245 up_write(&led_cdev->trigger_lock);
246#endif
247
248 led_cdev->flags |= LED_UNREGISTERING;
249
250 /* Stop blinking */
251 led_stop_software_blink(led_cdev);
252
253 led_set_brightness(led_cdev, LED_OFF);
254
255 flush_work(&led_cdev->set_brightness_work);
256
257 device_unregister(led_cdev->dev);
258
259 down_write(&leds_list_lock);
260 list_del(&led_cdev->node);
261 up_write(&leds_list_lock);
262
263 mutex_destroy(&led_cdev->led_access);
264}
265EXPORT_SYMBOL_GPL(led_classdev_unregister);
266
267static void devm_led_classdev_release(struct device *dev, void *res)
268{
269 led_classdev_unregister(*(struct led_classdev **)res);
270}
271
272/**
273 * devm_led_classdev_register - resource managed led_classdev_register()
274 * @parent: The device to register.
275 * @led_cdev: the led_classdev structure for this device.
276 */
277int devm_led_classdev_register(struct device *parent,
278 struct led_classdev *led_cdev)
279{
280 struct led_classdev **dr;
281 int rc;
282
283 dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL);
284 if (!dr)
285 return -ENOMEM;
286
287 rc = led_classdev_register(parent, led_cdev);
288 if (rc) {
289 devres_free(dr);
290 return rc;
291 }
292
293 *dr = led_cdev;
294 devres_add(parent, dr);
295
296 return 0;
297}
298EXPORT_SYMBOL_GPL(devm_led_classdev_register);
299
300static int devm_led_classdev_match(struct device *dev, void *res, void *data)
301{
302 struct led_cdev **p = res;
303
304 if (WARN_ON(!p || !*p))
305 return 0;
306
307 return *p == data;
308}
309
310/**
311 * devm_led_classdev_unregister() - resource managed led_classdev_unregister()
312 * @parent: The device to unregister.
313 * @led_cdev: the led_classdev structure for this device.
314 */
315void devm_led_classdev_unregister(struct device *dev,
316 struct led_classdev *led_cdev)
317{
318 WARN_ON(devres_release(dev,
319 devm_led_classdev_release,
320 devm_led_classdev_match, led_cdev));
321}
322EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
323
324static int __init leds_init(void)
325{
326 leds_class = class_create(THIS_MODULE, "leds");
327 if (IS_ERR(leds_class))
328 return PTR_ERR(leds_class);
329 leds_class->pm = &leds_class_dev_pm_ops;
330 leds_class->dev_groups = led_groups;
331 return 0;
332}
333
334static void __exit leds_exit(void)
335{
336 class_destroy(leds_class);
337}
338
339subsys_initcall(leds_init);
340module_exit(leds_exit);
341
342MODULE_AUTHOR("John Lenz, Richard Purdie");
343MODULE_LICENSE("GPL");
344MODULE_DESCRIPTION("LED Class Interface");