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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/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 <uapi/linux/uleds.h>
24#include "leds.h"
25
26static struct class *leds_class;
27
28static ssize_t brightness_show(struct device *dev,
29 struct device_attribute *attr, char *buf)
30{
31 struct led_classdev *led_cdev = dev_get_drvdata(dev);
32
33 /* no lock needed for this */
34 led_update_brightness(led_cdev);
35
36 return sprintf(buf, "%u\n", led_cdev->brightness);
37}
38
39static ssize_t brightness_store(struct device *dev,
40 struct device_attribute *attr, const char *buf, size_t size)
41{
42 struct led_classdev *led_cdev = dev_get_drvdata(dev);
43 unsigned long state;
44 ssize_t ret;
45
46 mutex_lock(&led_cdev->led_access);
47
48 if (led_sysfs_is_disabled(led_cdev)) {
49 ret = -EBUSY;
50 goto unlock;
51 }
52
53 ret = kstrtoul(buf, 10, &state);
54 if (ret)
55 goto unlock;
56
57 if (state == LED_OFF)
58 led_trigger_remove(led_cdev);
59 led_set_brightness(led_cdev, state);
60
61 ret = size;
62unlock:
63 mutex_unlock(&led_cdev->led_access);
64 return ret;
65}
66static DEVICE_ATTR_RW(brightness);
67
68static ssize_t max_brightness_show(struct device *dev,
69 struct device_attribute *attr, char *buf)
70{
71 struct led_classdev *led_cdev = dev_get_drvdata(dev);
72
73 return sprintf(buf, "%u\n", led_cdev->max_brightness);
74}
75static DEVICE_ATTR_RO(max_brightness);
76
77#ifdef CONFIG_LEDS_TRIGGERS
78static DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store);
79static struct attribute *led_trigger_attrs[] = {
80 &dev_attr_trigger.attr,
81 NULL,
82};
83static const struct attribute_group led_trigger_group = {
84 .attrs = led_trigger_attrs,
85};
86#endif
87
88static struct attribute *led_class_attrs[] = {
89 &dev_attr_brightness.attr,
90 &dev_attr_max_brightness.attr,
91 NULL,
92};
93
94static const struct attribute_group led_group = {
95 .attrs = led_class_attrs,
96};
97
98static const struct attribute_group *led_groups[] = {
99 &led_group,
100#ifdef CONFIG_LEDS_TRIGGERS
101 &led_trigger_group,
102#endif
103 NULL,
104};
105
106#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
107static ssize_t brightness_hw_changed_show(struct device *dev,
108 struct device_attribute *attr, char *buf)
109{
110 struct led_classdev *led_cdev = dev_get_drvdata(dev);
111
112 if (led_cdev->brightness_hw_changed == -1)
113 return -ENODATA;
114
115 return sprintf(buf, "%u\n", led_cdev->brightness_hw_changed);
116}
117
118static DEVICE_ATTR_RO(brightness_hw_changed);
119
120static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
121{
122 struct device *dev = led_cdev->dev;
123 int ret;
124
125 ret = device_create_file(dev, &dev_attr_brightness_hw_changed);
126 if (ret) {
127 dev_err(dev, "Error creating brightness_hw_changed\n");
128 return ret;
129 }
130
131 led_cdev->brightness_hw_changed_kn =
132 sysfs_get_dirent(dev->kobj.sd, "brightness_hw_changed");
133 if (!led_cdev->brightness_hw_changed_kn) {
134 dev_err(dev, "Error getting brightness_hw_changed kn\n");
135 device_remove_file(dev, &dev_attr_brightness_hw_changed);
136 return -ENXIO;
137 }
138
139 return 0;
140}
141
142static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
143{
144 sysfs_put(led_cdev->brightness_hw_changed_kn);
145 device_remove_file(led_cdev->dev, &dev_attr_brightness_hw_changed);
146}
147
148void led_classdev_notify_brightness_hw_changed(struct led_classdev *led_cdev,
149 enum led_brightness brightness)
150{
151 if (WARN_ON(!led_cdev->brightness_hw_changed_kn))
152 return;
153
154 led_cdev->brightness_hw_changed = brightness;
155 sysfs_notify_dirent(led_cdev->brightness_hw_changed_kn);
156}
157EXPORT_SYMBOL_GPL(led_classdev_notify_brightness_hw_changed);
158#else
159static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
160{
161 return 0;
162}
163static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
164{
165}
166#endif
167
168/**
169 * led_classdev_suspend - suspend an led_classdev.
170 * @led_cdev: the led_classdev to suspend.
171 */
172void led_classdev_suspend(struct led_classdev *led_cdev)
173{
174 led_cdev->flags |= LED_SUSPENDED;
175 led_set_brightness_nopm(led_cdev, 0);
176}
177EXPORT_SYMBOL_GPL(led_classdev_suspend);
178
179/**
180 * led_classdev_resume - resume an led_classdev.
181 * @led_cdev: the led_classdev to resume.
182 */
183void led_classdev_resume(struct led_classdev *led_cdev)
184{
185 led_set_brightness_nopm(led_cdev, led_cdev->brightness);
186
187 if (led_cdev->flash_resume)
188 led_cdev->flash_resume(led_cdev);
189
190 led_cdev->flags &= ~LED_SUSPENDED;
191}
192EXPORT_SYMBOL_GPL(led_classdev_resume);
193
194#ifdef CONFIG_PM_SLEEP
195static int led_suspend(struct device *dev)
196{
197 struct led_classdev *led_cdev = dev_get_drvdata(dev);
198
199 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
200 led_classdev_suspend(led_cdev);
201
202 return 0;
203}
204
205static int led_resume(struct device *dev)
206{
207 struct led_classdev *led_cdev = dev_get_drvdata(dev);
208
209 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
210 led_classdev_resume(led_cdev);
211
212 return 0;
213}
214#endif
215
216static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
217
218static int match_name(struct device *dev, const void *data)
219{
220 if (!dev_name(dev))
221 return 0;
222 return !strcmp(dev_name(dev), (char *)data);
223}
224
225static int led_classdev_next_name(const char *init_name, char *name,
226 size_t len)
227{
228 unsigned int i = 0;
229 int ret = 0;
230 struct device *dev;
231
232 strlcpy(name, init_name, len);
233
234 while ((ret < len) &&
235 (dev = class_find_device(leds_class, NULL, name, match_name))) {
236 put_device(dev);
237 ret = snprintf(name, len, "%s_%u", init_name, ++i);
238 }
239
240 if (ret >= len)
241 return -ENOMEM;
242
243 return i;
244}
245
246/**
247 * of_led_classdev_register - register a new object of led_classdev class.
248 *
249 * @parent: parent of LED device
250 * @led_cdev: the led_classdev structure for this device.
251 * @np: DT node describing this LED
252 */
253int of_led_classdev_register(struct device *parent, struct device_node *np,
254 struct led_classdev *led_cdev)
255{
256 char name[LED_MAX_NAME_SIZE];
257 int ret;
258
259 ret = led_classdev_next_name(led_cdev->name, name, sizeof(name));
260 if (ret < 0)
261 return ret;
262
263 led_cdev->dev = device_create_with_groups(leds_class, parent, 0,
264 led_cdev, led_cdev->groups, "%s", name);
265 if (IS_ERR(led_cdev->dev))
266 return PTR_ERR(led_cdev->dev);
267 led_cdev->dev->of_node = np;
268
269 if (ret)
270 dev_warn(parent, "Led %s renamed to %s due to name collision",
271 led_cdev->name, dev_name(led_cdev->dev));
272
273 if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) {
274 ret = led_add_brightness_hw_changed(led_cdev);
275 if (ret) {
276 device_unregister(led_cdev->dev);
277 return ret;
278 }
279 }
280
281 led_cdev->work_flags = 0;
282#ifdef CONFIG_LEDS_TRIGGERS
283 init_rwsem(&led_cdev->trigger_lock);
284#endif
285#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
286 led_cdev->brightness_hw_changed = -1;
287#endif
288 mutex_init(&led_cdev->led_access);
289 /* add to the list of leds */
290 down_write(&leds_list_lock);
291 list_add_tail(&led_cdev->node, &leds_list);
292 up_write(&leds_list_lock);
293
294 if (!led_cdev->max_brightness)
295 led_cdev->max_brightness = LED_FULL;
296
297 led_update_brightness(led_cdev);
298
299 led_init_core(led_cdev);
300
301#ifdef CONFIG_LEDS_TRIGGERS
302 led_trigger_set_default(led_cdev);
303#endif
304
305 dev_dbg(parent, "Registered led device: %s\n",
306 led_cdev->name);
307
308 return 0;
309}
310EXPORT_SYMBOL_GPL(of_led_classdev_register);
311
312/**
313 * led_classdev_unregister - unregisters a object of led_properties class.
314 * @led_cdev: the led device to unregister
315 *
316 * Unregisters a previously registered via led_classdev_register object.
317 */
318void led_classdev_unregister(struct led_classdev *led_cdev)
319{
320#ifdef CONFIG_LEDS_TRIGGERS
321 down_write(&led_cdev->trigger_lock);
322 if (led_cdev->trigger)
323 led_trigger_set(led_cdev, NULL);
324 up_write(&led_cdev->trigger_lock);
325#endif
326
327 led_cdev->flags |= LED_UNREGISTERING;
328
329 /* Stop blinking */
330 led_stop_software_blink(led_cdev);
331
332 led_set_brightness(led_cdev, LED_OFF);
333
334 flush_work(&led_cdev->set_brightness_work);
335
336 if (led_cdev->flags & LED_BRIGHT_HW_CHANGED)
337 led_remove_brightness_hw_changed(led_cdev);
338
339 device_unregister(led_cdev->dev);
340
341 down_write(&leds_list_lock);
342 list_del(&led_cdev->node);
343 up_write(&leds_list_lock);
344
345 mutex_destroy(&led_cdev->led_access);
346}
347EXPORT_SYMBOL_GPL(led_classdev_unregister);
348
349static void devm_led_classdev_release(struct device *dev, void *res)
350{
351 led_classdev_unregister(*(struct led_classdev **)res);
352}
353
354/**
355 * devm_of_led_classdev_register - resource managed led_classdev_register()
356 *
357 * @parent: parent of LED device
358 * @led_cdev: the led_classdev structure for this device.
359 */
360int devm_of_led_classdev_register(struct device *parent,
361 struct device_node *np,
362 struct led_classdev *led_cdev)
363{
364 struct led_classdev **dr;
365 int rc;
366
367 dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL);
368 if (!dr)
369 return -ENOMEM;
370
371 rc = of_led_classdev_register(parent, np, led_cdev);
372 if (rc) {
373 devres_free(dr);
374 return rc;
375 }
376
377 *dr = led_cdev;
378 devres_add(parent, dr);
379
380 return 0;
381}
382EXPORT_SYMBOL_GPL(devm_of_led_classdev_register);
383
384static int devm_led_classdev_match(struct device *dev, void *res, void *data)
385{
386 struct led_cdev **p = res;
387
388 if (WARN_ON(!p || !*p))
389 return 0;
390
391 return *p == data;
392}
393
394/**
395 * devm_led_classdev_unregister() - resource managed led_classdev_unregister()
396 * @parent: The device to unregister.
397 * @led_cdev: the led_classdev structure for this device.
398 */
399void devm_led_classdev_unregister(struct device *dev,
400 struct led_classdev *led_cdev)
401{
402 WARN_ON(devres_release(dev,
403 devm_led_classdev_release,
404 devm_led_classdev_match, led_cdev));
405}
406EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
407
408static int __init leds_init(void)
409{
410 leds_class = class_create(THIS_MODULE, "leds");
411 if (IS_ERR(leds_class))
412 return PTR_ERR(leds_class);
413 leds_class->pm = &leds_class_dev_pm_ops;
414 leds_class->dev_groups = led_groups;
415 return 0;
416}
417
418static void __exit leds_exit(void)
419{
420 class_destroy(leds_class);
421}
422
423subsys_initcall(leds_init);
424module_exit(leds_exit);
425
426MODULE_AUTHOR("John Lenz, Richard Purdie");
427MODULE_LICENSE("GPL");
428MODULE_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/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");