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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// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * LED Class Core
4 *
5 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
6 * Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com>
7 */
8
9#include <linux/ctype.h>
10#include <linux/device.h>
11#include <linux/err.h>
12#include <linux/init.h>
13#include <linux/kernel.h>
14#include <linux/leds.h>
15#include <linux/list.h>
16#include <linux/module.h>
17#include <linux/property.h>
18#include <linux/slab.h>
19#include <linux/spinlock.h>
20#include <linux/timer.h>
21#include <uapi/linux/uleds.h>
22#include "leds.h"
23
24static struct class *leds_class;
25
26static ssize_t brightness_show(struct device *dev,
27 struct device_attribute *attr, char *buf)
28{
29 struct led_classdev *led_cdev = dev_get_drvdata(dev);
30
31 /* no lock needed for this */
32 led_update_brightness(led_cdev);
33
34 return sprintf(buf, "%u\n", led_cdev->brightness);
35}
36
37static ssize_t brightness_store(struct device *dev,
38 struct device_attribute *attr, const char *buf, size_t size)
39{
40 struct led_classdev *led_cdev = dev_get_drvdata(dev);
41 unsigned long state;
42 ssize_t ret;
43
44 mutex_lock(&led_cdev->led_access);
45
46 if (led_sysfs_is_disabled(led_cdev)) {
47 ret = -EBUSY;
48 goto unlock;
49 }
50
51 ret = kstrtoul(buf, 10, &state);
52 if (ret)
53 goto unlock;
54
55 if (state == LED_OFF)
56 led_trigger_remove(led_cdev);
57 led_set_brightness(led_cdev, state);
58 flush_work(&led_cdev->set_brightness_work);
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#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
106static ssize_t brightness_hw_changed_show(struct device *dev,
107 struct device_attribute *attr, char *buf)
108{
109 struct led_classdev *led_cdev = dev_get_drvdata(dev);
110
111 if (led_cdev->brightness_hw_changed == -1)
112 return -ENODATA;
113
114 return sprintf(buf, "%u\n", led_cdev->brightness_hw_changed);
115}
116
117static DEVICE_ATTR_RO(brightness_hw_changed);
118
119static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
120{
121 struct device *dev = led_cdev->dev;
122 int ret;
123
124 ret = device_create_file(dev, &dev_attr_brightness_hw_changed);
125 if (ret) {
126 dev_err(dev, "Error creating brightness_hw_changed\n");
127 return ret;
128 }
129
130 led_cdev->brightness_hw_changed_kn =
131 sysfs_get_dirent(dev->kobj.sd, "brightness_hw_changed");
132 if (!led_cdev->brightness_hw_changed_kn) {
133 dev_err(dev, "Error getting brightness_hw_changed kn\n");
134 device_remove_file(dev, &dev_attr_brightness_hw_changed);
135 return -ENXIO;
136 }
137
138 return 0;
139}
140
141static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
142{
143 sysfs_put(led_cdev->brightness_hw_changed_kn);
144 device_remove_file(led_cdev->dev, &dev_attr_brightness_hw_changed);
145}
146
147void led_classdev_notify_brightness_hw_changed(struct led_classdev *led_cdev,
148 enum led_brightness brightness)
149{
150 if (WARN_ON(!led_cdev->brightness_hw_changed_kn))
151 return;
152
153 led_cdev->brightness_hw_changed = brightness;
154 sysfs_notify_dirent(led_cdev->brightness_hw_changed_kn);
155}
156EXPORT_SYMBOL_GPL(led_classdev_notify_brightness_hw_changed);
157#else
158static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
159{
160 return 0;
161}
162static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
163{
164}
165#endif
166
167/**
168 * led_classdev_suspend - suspend an led_classdev.
169 * @led_cdev: the led_classdev to suspend.
170 */
171void led_classdev_suspend(struct led_classdev *led_cdev)
172{
173 led_cdev->flags |= LED_SUSPENDED;
174 led_set_brightness_nopm(led_cdev, 0);
175}
176EXPORT_SYMBOL_GPL(led_classdev_suspend);
177
178/**
179 * led_classdev_resume - resume an led_classdev.
180 * @led_cdev: the led_classdev to resume.
181 */
182void led_classdev_resume(struct led_classdev *led_cdev)
183{
184 led_set_brightness_nopm(led_cdev, led_cdev->brightness);
185
186 if (led_cdev->flash_resume)
187 led_cdev->flash_resume(led_cdev);
188
189 led_cdev->flags &= ~LED_SUSPENDED;
190}
191EXPORT_SYMBOL_GPL(led_classdev_resume);
192
193#ifdef CONFIG_PM_SLEEP
194static int led_suspend(struct device *dev)
195{
196 struct led_classdev *led_cdev = dev_get_drvdata(dev);
197
198 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
199 led_classdev_suspend(led_cdev);
200
201 return 0;
202}
203
204static int led_resume(struct device *dev)
205{
206 struct led_classdev *led_cdev = dev_get_drvdata(dev);
207
208 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
209 led_classdev_resume(led_cdev);
210
211 return 0;
212}
213#endif
214
215static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
216
217static int led_classdev_next_name(const char *init_name, char *name,
218 size_t len)
219{
220 unsigned int i = 0;
221 int ret = 0;
222 struct device *dev;
223
224 strlcpy(name, init_name, len);
225
226 while ((ret < len) &&
227 (dev = class_find_device_by_name(leds_class, name))) {
228 put_device(dev);
229 ret = snprintf(name, len, "%s_%u", init_name, ++i);
230 }
231
232 if (ret >= len)
233 return -ENOMEM;
234
235 return i;
236}
237
238/**
239 * led_classdev_register_ext - register a new object of led_classdev class
240 * with init data.
241 *
242 * @parent: parent of LED device
243 * @led_cdev: the led_classdev structure for this device.
244 * @init_data: LED class device initialization data
245 */
246int led_classdev_register_ext(struct device *parent,
247 struct led_classdev *led_cdev,
248 struct led_init_data *init_data)
249{
250 char composed_name[LED_MAX_NAME_SIZE];
251 char final_name[LED_MAX_NAME_SIZE];
252 const char *proposed_name = composed_name;
253 int ret;
254
255 if (init_data) {
256 if (init_data->devname_mandatory && !init_data->devicename) {
257 dev_err(parent, "Mandatory device name is missing");
258 return -EINVAL;
259 }
260 ret = led_compose_name(parent, init_data, composed_name);
261 if (ret < 0)
262 return ret;
263 } else {
264 proposed_name = led_cdev->name;
265 }
266
267 ret = led_classdev_next_name(proposed_name, final_name, sizeof(final_name));
268 if (ret < 0)
269 return ret;
270
271 mutex_init(&led_cdev->led_access);
272 mutex_lock(&led_cdev->led_access);
273 led_cdev->dev = device_create_with_groups(leds_class, parent, 0,
274 led_cdev, led_cdev->groups, "%s", final_name);
275 if (IS_ERR(led_cdev->dev)) {
276 mutex_unlock(&led_cdev->led_access);
277 return PTR_ERR(led_cdev->dev);
278 }
279 if (init_data && init_data->fwnode)
280 led_cdev->dev->fwnode = init_data->fwnode;
281
282 if (ret)
283 dev_warn(parent, "Led %s renamed to %s due to name collision",
284 led_cdev->name, dev_name(led_cdev->dev));
285
286 if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) {
287 ret = led_add_brightness_hw_changed(led_cdev);
288 if (ret) {
289 device_unregister(led_cdev->dev);
290 led_cdev->dev = NULL;
291 mutex_unlock(&led_cdev->led_access);
292 return ret;
293 }
294 }
295
296 led_cdev->work_flags = 0;
297#ifdef CONFIG_LEDS_TRIGGERS
298 init_rwsem(&led_cdev->trigger_lock);
299#endif
300#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
301 led_cdev->brightness_hw_changed = -1;
302#endif
303 /* add to the list of leds */
304 down_write(&leds_list_lock);
305 list_add_tail(&led_cdev->node, &leds_list);
306 up_write(&leds_list_lock);
307
308 if (!led_cdev->max_brightness)
309 led_cdev->max_brightness = LED_FULL;
310
311 led_update_brightness(led_cdev);
312
313 led_init_core(led_cdev);
314
315#ifdef CONFIG_LEDS_TRIGGERS
316 led_trigger_set_default(led_cdev);
317#endif
318
319 mutex_unlock(&led_cdev->led_access);
320
321 dev_dbg(parent, "Registered led device: %s\n",
322 led_cdev->name);
323
324 return 0;
325}
326EXPORT_SYMBOL_GPL(led_classdev_register_ext);
327
328/**
329 * led_classdev_unregister - unregisters a object of led_properties class.
330 * @led_cdev: the led device to unregister
331 *
332 * Unregisters a previously registered via led_classdev_register object.
333 */
334void led_classdev_unregister(struct led_classdev *led_cdev)
335{
336 if (IS_ERR_OR_NULL(led_cdev->dev))
337 return;
338
339#ifdef CONFIG_LEDS_TRIGGERS
340 down_write(&led_cdev->trigger_lock);
341 if (led_cdev->trigger)
342 led_trigger_set(led_cdev, NULL);
343 up_write(&led_cdev->trigger_lock);
344#endif
345
346 led_cdev->flags |= LED_UNREGISTERING;
347
348 /* Stop blinking */
349 led_stop_software_blink(led_cdev);
350
351 led_set_brightness(led_cdev, LED_OFF);
352
353 flush_work(&led_cdev->set_brightness_work);
354
355 if (led_cdev->flags & LED_BRIGHT_HW_CHANGED)
356 led_remove_brightness_hw_changed(led_cdev);
357
358 device_unregister(led_cdev->dev);
359
360 down_write(&leds_list_lock);
361 list_del(&led_cdev->node);
362 up_write(&leds_list_lock);
363
364 mutex_destroy(&led_cdev->led_access);
365}
366EXPORT_SYMBOL_GPL(led_classdev_unregister);
367
368static void devm_led_classdev_release(struct device *dev, void *res)
369{
370 led_classdev_unregister(*(struct led_classdev **)res);
371}
372
373/**
374 * devm_led_classdev_register_ext - resource managed led_classdev_register_ext()
375 *
376 * @parent: parent of LED device
377 * @led_cdev: the led_classdev structure for this device.
378 * @init_data: LED class device initialization data
379 */
380int devm_led_classdev_register_ext(struct device *parent,
381 struct led_classdev *led_cdev,
382 struct led_init_data *init_data)
383{
384 struct led_classdev **dr;
385 int rc;
386
387 dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL);
388 if (!dr)
389 return -ENOMEM;
390
391 rc = led_classdev_register_ext(parent, led_cdev, init_data);
392 if (rc) {
393 devres_free(dr);
394 return rc;
395 }
396
397 *dr = led_cdev;
398 devres_add(parent, dr);
399
400 return 0;
401}
402EXPORT_SYMBOL_GPL(devm_led_classdev_register_ext);
403
404static int devm_led_classdev_match(struct device *dev, void *res, void *data)
405{
406 struct led_cdev **p = res;
407
408 if (WARN_ON(!p || !*p))
409 return 0;
410
411 return *p == data;
412}
413
414/**
415 * devm_led_classdev_unregister() - resource managed led_classdev_unregister()
416 * @parent: The device to unregister.
417 * @led_cdev: the led_classdev structure for this device.
418 */
419void devm_led_classdev_unregister(struct device *dev,
420 struct led_classdev *led_cdev)
421{
422 WARN_ON(devres_release(dev,
423 devm_led_classdev_release,
424 devm_led_classdev_match, led_cdev));
425}
426EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
427
428static int __init leds_init(void)
429{
430 leds_class = class_create(THIS_MODULE, "leds");
431 if (IS_ERR(leds_class))
432 return PTR_ERR(leds_class);
433 leds_class->pm = &leds_class_dev_pm_ops;
434 leds_class->dev_groups = led_groups;
435 return 0;
436}
437
438static void __exit leds_exit(void)
439{
440 class_destroy(leds_class);
441}
442
443subsys_initcall(leds_init);
444module_exit(leds_exit);
445
446MODULE_AUTHOR("John Lenz, Richard Purdie");
447MODULE_LICENSE("GPL");
448MODULE_DESCRIPTION("LED Class Interface");