leds: trigger: gpio: Avoid warning on update of inverted
[linux-block.git] / drivers / leds / led-class.c
CommitLineData
d2912cb1 1// SPDX-License-Identifier: GPL-2.0-only
c72a1d60
RP
2/*
3 * LED Class Core
4 *
5 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
f8a7c6fe 6 * Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com>
c72a1d60
RP
7 */
8
04713306
JA
9#include <linux/ctype.h>
10#include <linux/device.h>
11#include <linux/err.h>
c72a1d60 12#include <linux/init.h>
04713306
JA
13#include <linux/kernel.h>
14#include <linux/leds.h>
c72a1d60 15#include <linux/list.h>
04713306 16#include <linux/module.h>
fd81d7e9 17#include <linux/property.h>
04713306 18#include <linux/slab.h>
c72a1d60 19#include <linux/spinlock.h>
9067359f 20#include <linux/timer.h>
eb1ce746 21#include <uapi/linux/uleds.h>
699a8c7c 22#include <linux/of.h>
c72a1d60
RP
23#include "leds.h"
24
25static struct class *leds_class;
26
5baa7503 27static ssize_t brightness_show(struct device *dev,
f8a7c6fe 28 struct device_attribute *attr, char *buf)
c72a1d60 29{
f8a7c6fe 30 struct led_classdev *led_cdev = dev_get_drvdata(dev);
c72a1d60
RP
31
32 /* no lock needed for this */
29d76dfa 33 led_update_brightness(led_cdev);
c72a1d60 34
dd8e5a20 35 return sprintf(buf, "%u\n", led_cdev->brightness);
c72a1d60
RP
36}
37
5baa7503 38static ssize_t brightness_store(struct device *dev,
f8a7c6fe 39 struct device_attribute *attr, const char *buf, size_t size)
c72a1d60 40{
f8a7c6fe 41 struct led_classdev *led_cdev = dev_get_drvdata(dev);
872b86be 42 unsigned long state;
acd899e4
JA
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 }
c72a1d60 51
872b86be
SK
52 ret = kstrtoul(buf, 10, &state);
53 if (ret)
acd899e4 54 goto unlock;
3dc7b82e 55
872b86be
SK
56 if (state == LED_OFF)
57 led_trigger_remove(led_cdev);
4d71a4a1 58 led_set_brightness(led_cdev, state);
0db37915 59 flush_work(&led_cdev->set_brightness_work);
0013b23d 60
acd899e4
JA
61 ret = size;
62unlock:
63 mutex_unlock(&led_cdev->led_access);
64 return ret;
c72a1d60 65}
5baa7503 66static DEVICE_ATTR_RW(brightness);
c72a1d60 67
38419612 68static ssize_t max_brightness_show(struct device *dev,
1bd465e6
GL
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}
38419612 75static DEVICE_ATTR_RO(max_brightness);
1bd465e6 76
c3bc9956 77#ifdef CONFIG_LEDS_TRIGGERS
11f70002
AM
78static BIN_ATTR(trigger, 0644, led_trigger_read, led_trigger_write, 0);
79static struct bin_attribute *led_trigger_bin_attrs[] = {
80 &bin_attr_trigger,
5baa7503
GKH
81 NULL,
82};
83static const struct attribute_group led_trigger_group = {
11f70002 84 .bin_attrs = led_trigger_bin_attrs,
5baa7503
GKH
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,
c3bc9956 102#endif
5baa7503 103 NULL,
14b5d6dd 104};
c72a1d60 105
0cb8eb30
HG
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
c72a1d60
RP
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;
81fe8e5b 175 led_set_brightness_nopm(led_cdev, 0);
c72a1d60
RP
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{
81fe8e5b 185 led_set_brightness_nopm(led_cdev, led_cdev->brightness);
7aea8389
JA
186
187 if (led_cdev->flash_resume)
188 led_cdev->flash_resume(led_cdev);
189
c72a1d60
RP
190 led_cdev->flags &= ~LED_SUSPENDED;
191}
192EXPORT_SYMBOL_GPL(led_classdev_resume);
193
084609bf 194#ifdef CONFIG_PM_SLEEP
73e1ab41 195static int led_suspend(struct device *dev)
859cb7f2
RP
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}
084609bf 214#endif
859cb7f2 215
084609bf 216static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
73e1ab41 217
699a8c7c
TV
218/**
219 * of_led_get() - request a LED device via the LED framework
220 * @np: device node to get the LED device from
221 * @index: the index of the LED
222 *
223 * Returns the LED device parsed from the phandle specified in the "leds"
224 * property of a device tree node or a negative error-code on failure.
225 */
226struct led_classdev *of_led_get(struct device_node *np, int index)
227{
228 struct device *led_dev;
229 struct led_classdev *led_cdev;
230 struct device_node *led_node;
231
232 led_node = of_parse_phandle(np, "leds", index);
233 if (!led_node)
234 return ERR_PTR(-ENOENT);
235
236 led_dev = class_find_device_by_of_node(leds_class, led_node);
237 of_node_put(led_node);
238
239 if (!led_dev)
240 return ERR_PTR(-EPROBE_DEFER);
241
242 led_cdev = dev_get_drvdata(led_dev);
243
244 if (!try_module_get(led_cdev->dev->parent->driver->owner))
245 return ERR_PTR(-ENODEV);
246
247 return led_cdev;
248}
249EXPORT_SYMBOL_GPL(of_led_get);
250
251/**
252 * led_put() - release a LED device
253 * @led_cdev: LED device
254 */
255void led_put(struct led_classdev *led_cdev)
256{
257 module_put(led_cdev->dev->parent->driver->owner);
258}
259EXPORT_SYMBOL_GPL(led_put);
260
e389240a
JJH
261static void devm_led_release(struct device *dev, void *res)
262{
263 struct led_classdev **p = res;
264
265 led_put(*p);
266}
267
268/**
269 * devm_of_led_get - Resource-managed request of a LED device
270 * @dev: LED consumer
271 * @index: index of the LED to obtain in the consumer
272 *
273 * The device node of the device is parse to find the request LED device.
274 * The LED device returned from this function is automatically released
275 * on driver detach.
276 *
277 * @return a pointer to a LED device or ERR_PTR(errno) on failure.
278 */
279struct led_classdev *__must_check devm_of_led_get(struct device *dev,
280 int index)
281{
282 struct led_classdev *led;
283 struct led_classdev **dr;
284
285 if (!dev)
286 return ERR_PTR(-EINVAL);
287
288 /* Not using device tree? */
289 if (!IS_ENABLED(CONFIG_OF) || !dev->of_node)
290 return ERR_PTR(-ENOTSUPP);
291
292 led = of_led_get(dev->of_node, index);
293 if (IS_ERR(led))
294 return led;
295
296 dr = devres_alloc(devm_led_release, sizeof(struct led_classdev *),
297 GFP_KERNEL);
298 if (!dr) {
299 led_put(led);
300 return ERR_PTR(-ENOMEM);
301 }
302
303 *dr = led;
304 devres_add(dev, dr);
305
306 return led;
307}
308EXPORT_SYMBOL_GPL(devm_of_led_get);
309
a96aa64c
RRD
310static int led_classdev_next_name(const char *init_name, char *name,
311 size_t len)
312{
313 unsigned int i = 0;
314 int ret = 0;
e5b5a61f 315 struct device *dev;
a96aa64c
RRD
316
317 strlcpy(name, init_name, len);
318
e5b5a61f 319 while ((ret < len) &&
6cda08a2 320 (dev = class_find_device_by_name(leds_class, name))) {
e5b5a61f 321 put_device(dev);
a96aa64c 322 ret = snprintf(name, len, "%s_%u", init_name, ++i);
e5b5a61f 323 }
a96aa64c
RRD
324
325 if (ret >= len)
326 return -ENOMEM;
327
328 return i;
329}
330
c72a1d60 331/**
b2b998c0
JA
332 * led_classdev_register_ext - register a new object of led_classdev class
333 * with init data.
442c6098
RM
334 *
335 * @parent: parent of LED device
c72a1d60 336 * @led_cdev: the led_classdev structure for this device.
b2b998c0 337 * @init_data: LED class device initialization data
c72a1d60 338 */
b2b998c0
JA
339int led_classdev_register_ext(struct device *parent,
340 struct led_classdev *led_cdev,
341 struct led_init_data *init_data)
c72a1d60 342{
bb4e9af0
JA
343 char composed_name[LED_MAX_NAME_SIZE];
344 char final_name[LED_MAX_NAME_SIZE];
345 const char *proposed_name = composed_name;
a96aa64c
RRD
346 int ret;
347
bb4e9af0
JA
348 if (init_data) {
349 if (init_data->devname_mandatory && !init_data->devicename) {
350 dev_err(parent, "Mandatory device name is missing");
351 return -EINVAL;
352 }
353 ret = led_compose_name(parent, init_data, composed_name);
354 if (ret < 0)
355 return ret;
356 } else {
357 proposed_name = led_cdev->name;
358 }
359
360 ret = led_classdev_next_name(proposed_name, final_name, sizeof(final_name));
a96aa64c
RRD
361 if (ret < 0)
362 return ret;
363
6d71021a
LH
364 mutex_init(&led_cdev->led_access);
365 mutex_lock(&led_cdev->led_access);
d0d480cc 366 led_cdev->dev = device_create_with_groups(leds_class, parent, 0,
bb4e9af0 367 led_cdev, led_cdev->groups, "%s", final_name);
6d71021a
LH
368 if (IS_ERR(led_cdev->dev)) {
369 mutex_unlock(&led_cdev->led_access);
f8a7c6fe 370 return PTR_ERR(led_cdev->dev);
6d71021a 371 }
7a349e8c 372 if (init_data && init_data->fwnode) {
fd81d7e9 373 led_cdev->dev->fwnode = init_data->fwnode;
7a349e8c
JJH
374 led_cdev->dev->of_node = to_of_node(init_data->fwnode);
375 }
c72a1d60 376
a96aa64c 377 if (ret)
6f06c7f8 378 dev_warn(parent, "Led %s renamed to %s due to name collision",
64ed6588 379 proposed_name, dev_name(led_cdev->dev));
a96aa64c 380
0cb8eb30
HG
381 if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) {
382 ret = led_add_brightness_hw_changed(led_cdev);
383 if (ret) {
384 device_unregister(led_cdev->dev);
1dbb9fb4 385 led_cdev->dev = NULL;
6d71021a 386 mutex_unlock(&led_cdev->led_access);
0cb8eb30
HG
387 return ret;
388 }
389 }
390
a9c6ce57 391 led_cdev->work_flags = 0;
270c3957
RP
392#ifdef CONFIG_LEDS_TRIGGERS
393 init_rwsem(&led_cdev->trigger_lock);
0cb8eb30
HG
394#endif
395#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
396 led_cdev->brightness_hw_changed = -1;
270c3957 397#endif
c72a1d60 398 /* add to the list of leds */
72f8da32 399 down_write(&leds_list_lock);
c72a1d60 400 list_add_tail(&led_cdev->node, &leds_list);
72f8da32 401 up_write(&leds_list_lock);
c72a1d60 402
1bd465e6
GL
403 if (!led_cdev->max_brightness)
404 led_cdev->max_brightness = LED_FULL;
405
29d76dfa
HMH
406 led_update_brightness(led_cdev);
407
757b06ae 408 led_init_core(led_cdev);
5ada28bf 409
c3bc9956 410#ifdef CONFIG_LEDS_TRIGGERS
12fda168 411 led_trigger_set_default(led_cdev);
c3bc9956
RP
412#endif
413
6d71021a
LH
414 mutex_unlock(&led_cdev->led_access);
415
d23e7b8b 416 dev_dbg(parent, "Registered led device: %s\n",
f8a7c6fe 417 led_cdev->name);
c72a1d60
RP
418
419 return 0;
420}
b2b998c0 421EXPORT_SYMBOL_GPL(led_classdev_register_ext);
c72a1d60
RP
422
423/**
0266a458 424 * led_classdev_unregister - unregisters a object of led_properties class.
70d63ccc 425 * @led_cdev: the led device to unregister
c72a1d60
RP
426 *
427 * Unregisters a previously registered via led_classdev_register object.
428 */
b844eba2 429void led_classdev_unregister(struct led_classdev *led_cdev)
c72a1d60 430{
1dbb9fb4
AS
431 if (IS_ERR_OR_NULL(led_cdev->dev))
432 return;
433
c3bc9956 434#ifdef CONFIG_LEDS_TRIGGERS
dc47206e 435 down_write(&led_cdev->trigger_lock);
c3bc9956
RP
436 if (led_cdev->trigger)
437 led_trigger_set(led_cdev, NULL);
dc47206e 438 up_write(&led_cdev->trigger_lock);
c3bc9956 439#endif
c72a1d60 440
d84d80f3
HK
441 led_cdev->flags |= LED_UNREGISTERING;
442
5ada28bf 443 /* Stop blinking */
d23a22a7 444 led_stop_software_blink(led_cdev);
d1aa577f 445
19cd67e2 446 led_set_brightness(led_cdev, LED_OFF);
5ada28bf 447
d1aa577f
MK
448 flush_work(&led_cdev->set_brightness_work);
449
0cb8eb30
HG
450 if (led_cdev->flags & LED_BRIGHT_HW_CHANGED)
451 led_remove_brightness_hw_changed(led_cdev);
452
b844eba2 453 device_unregister(led_cdev->dev);
c72a1d60 454
72f8da32 455 down_write(&leds_list_lock);
c72a1d60 456 list_del(&led_cdev->node);
72f8da32 457 up_write(&leds_list_lock);
acd899e4
JA
458
459 mutex_destroy(&led_cdev->led_access);
c72a1d60 460}
b844eba2 461EXPORT_SYMBOL_GPL(led_classdev_unregister);
c72a1d60 462
ca1bb4ee
BA
463static void devm_led_classdev_release(struct device *dev, void *res)
464{
465 led_classdev_unregister(*(struct led_classdev **)res);
466}
467
468/**
b2b998c0 469 * devm_led_classdev_register_ext - resource managed led_classdev_register_ext()
442c6098
RM
470 *
471 * @parent: parent of LED device
ca1bb4ee 472 * @led_cdev: the led_classdev structure for this device.
b2b998c0 473 * @init_data: LED class device initialization data
ca1bb4ee 474 */
b2b998c0
JA
475int devm_led_classdev_register_ext(struct device *parent,
476 struct led_classdev *led_cdev,
477 struct led_init_data *init_data)
ca1bb4ee
BA
478{
479 struct led_classdev **dr;
480 int rc;
481
482 dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL);
483 if (!dr)
484 return -ENOMEM;
485
b2b998c0 486 rc = led_classdev_register_ext(parent, led_cdev, init_data);
ca1bb4ee
BA
487 if (rc) {
488 devres_free(dr);
489 return rc;
490 }
491
492 *dr = led_cdev;
493 devres_add(parent, dr);
494
495 return 0;
496}
b2b998c0 497EXPORT_SYMBOL_GPL(devm_led_classdev_register_ext);
ca1bb4ee
BA
498
499static int devm_led_classdev_match(struct device *dev, void *res, void *data)
500{
4b83cf07 501 struct led_classdev **p = res;
ca1bb4ee
BA
502
503 if (WARN_ON(!p || !*p))
504 return 0;
505
506 return *p == data;
507}
508
509/**
510 * devm_led_classdev_unregister() - resource managed led_classdev_unregister()
511 * @parent: The device to unregister.
512 * @led_cdev: the led_classdev structure for this device.
513 */
514void devm_led_classdev_unregister(struct device *dev,
515 struct led_classdev *led_cdev)
516{
517 WARN_ON(devres_release(dev,
518 devm_led_classdev_release,
519 devm_led_classdev_match, led_cdev));
520}
521EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
522
c72a1d60
RP
523static int __init leds_init(void)
524{
525 leds_class = class_create(THIS_MODULE, "leds");
526 if (IS_ERR(leds_class))
527 return PTR_ERR(leds_class);
73e1ab41 528 leds_class->pm = &leds_class_dev_pm_ops;
5baa7503 529 leds_class->dev_groups = led_groups;
c72a1d60
RP
530 return 0;
531}
532
533static void __exit leds_exit(void)
534{
535 class_destroy(leds_class);
536}
537
538subsys_initcall(leds_init);
539module_exit(leds_exit);
540
541MODULE_AUTHOR("John Lenz, Richard Purdie");
542MODULE_LICENSE("GPL");
543MODULE_DESCRIPTION("LED Class Interface");