1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * LED Class Core
4 *
5 * Copyright 2005-2006 Openedhand Ltd.
6 *
7 * Author: Richard Purdie <rpurdie@openedhand.com>
8 */
9
10#include <linux/kernel.h>
11#include <linux/leds.h>
12#include <linux/list.h>
13#include <linux/module.h>
14#include <linux/mutex.h>
15#include <linux/of.h>
16#include <linux/property.h>
17#include <linux/rwsem.h>
18#include <linux/slab.h>
19#include <uapi/linux/uleds.h>
20#include "leds.h"
21
22DECLARE_RWSEM(leds_list_lock);
23EXPORT_SYMBOL_GPL(leds_list_lock);
24
25LIST_HEAD(leds_list);
26EXPORT_SYMBOL_GPL(leds_list);
27
28const char * const led_colors[LED_COLOR_ID_MAX] = {
29 [LED_COLOR_ID_WHITE] = "white",
30 [LED_COLOR_ID_RED] = "red",
31 [LED_COLOR_ID_GREEN] = "green",
32 [LED_COLOR_ID_BLUE] = "blue",
33 [LED_COLOR_ID_AMBER] = "amber",
34 [LED_COLOR_ID_VIOLET] = "violet",
35 [LED_COLOR_ID_YELLOW] = "yellow",
36 [LED_COLOR_ID_IR] = "ir",
37 [LED_COLOR_ID_MULTI] = "multicolor",
38 [LED_COLOR_ID_RGB] = "rgb",
39 [LED_COLOR_ID_PURPLE] = "purple",
40 [LED_COLOR_ID_ORANGE] = "orange",
41 [LED_COLOR_ID_PINK] = "pink",
42 [LED_COLOR_ID_CYAN] = "cyan",
43 [LED_COLOR_ID_LIME] = "lime",
44};
45EXPORT_SYMBOL_GPL(led_colors);
46
47static int __led_set_brightness(struct led_classdev *led_cdev, unsigned int value)
48{
49 if (!led_cdev->brightness_set)
50 return -ENOTSUPP;
51
52 led_cdev->brightness_set(led_cdev, value);
53
54 return 0;
55}
56
57static int __led_set_brightness_blocking(struct led_classdev *led_cdev, unsigned int value)
58{
59 if (!led_cdev->brightness_set_blocking)
60 return -ENOTSUPP;
61
62 return led_cdev->brightness_set_blocking(led_cdev, value);
63}
64
65static void led_timer_function(struct timer_list *t)
66{
67 struct led_classdev *led_cdev = from_timer(led_cdev, t, blink_timer);
68 unsigned long brightness;
69 unsigned long delay;
70
71 if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) {
72 led_set_brightness_nosleep(led_cdev, value: LED_OFF);
73 clear_bit(LED_BLINK_SW, addr: &led_cdev->work_flags);
74 return;
75 }
76
77 if (test_and_clear_bit(LED_BLINK_ONESHOT_STOP,
78 addr: &led_cdev->work_flags)) {
79 clear_bit(LED_BLINK_SW, addr: &led_cdev->work_flags);
80 return;
81 }
82
83 brightness = led_get_brightness(led_cdev);
84 if (!brightness) {
85 /* Time to switch the LED on. */
86 if (test_and_clear_bit(LED_BLINK_BRIGHTNESS_CHANGE,
87 addr: &led_cdev->work_flags))
88 brightness = led_cdev->new_blink_brightness;
89 else
90 brightness = led_cdev->blink_brightness;
91 delay = led_cdev->blink_delay_on;
92 } else {
93 /* Store the current brightness value to be able
94 * to restore it when the delay_off period is over.
95 */
96 led_cdev->blink_brightness = brightness;
97 brightness = LED_OFF;
98 delay = led_cdev->blink_delay_off;
99 }
100
101 led_set_brightness_nosleep(led_cdev, value: brightness);
102
103 /* Return in next iteration if led is in one-shot mode and we are in
104 * the final blink state so that the led is toggled each delay_on +
105 * delay_off milliseconds in worst case.
106 */
107 if (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags)) {
108 if (test_bit(LED_BLINK_INVERT, &led_cdev->work_flags)) {
109 if (brightness)
110 set_bit(LED_BLINK_ONESHOT_STOP,
111 addr: &led_cdev->work_flags);
112 } else {
113 if (!brightness)
114 set_bit(LED_BLINK_ONESHOT_STOP,
115 addr: &led_cdev->work_flags);
116 }
117 }
118
119 mod_timer(timer: &led_cdev->blink_timer, expires: jiffies + msecs_to_jiffies(m: delay));
120}
121
122static void set_brightness_delayed_set_brightness(struct led_classdev *led_cdev,
123 unsigned int value)
124{
125 int ret = 0;
126
127 ret = __led_set_brightness(led_cdev, value);
128 if (ret == -ENOTSUPP)
129 ret = __led_set_brightness_blocking(led_cdev, value);
130 if (ret < 0 &&
131 /* LED HW might have been unplugged, therefore don't warn */
132 !(ret == -ENODEV && (led_cdev->flags & LED_UNREGISTERING) &&
133 (led_cdev->flags & LED_HW_PLUGGABLE)))
134 dev_err(led_cdev->dev,
135 "Setting an LED's brightness failed (%d)\n", ret);
136}
137
138static void set_brightness_delayed(struct work_struct *ws)
139{
140 struct led_classdev *led_cdev =
141 container_of(ws, struct led_classdev, set_brightness_work);
142
143 if (test_and_clear_bit(LED_BLINK_DISABLE, addr: &led_cdev->work_flags)) {
144 led_stop_software_blink(led_cdev);
145 set_bit(LED_SET_BRIGHTNESS_OFF, addr: &led_cdev->work_flags);
146 }
147
148 /*
149 * Triggers may call led_set_brightness(LED_OFF),
150 * led_set_brightness(LED_FULL) in quick succession to disable blinking
151 * and turn the LED on. Both actions may have been scheduled to run
152 * before this work item runs once. To make sure this works properly
153 * handle LED_SET_BRIGHTNESS_OFF first.
154 */
155 if (test_and_clear_bit(LED_SET_BRIGHTNESS_OFF, addr: &led_cdev->work_flags))
156 set_brightness_delayed_set_brightness(led_cdev, value: LED_OFF);
157
158 if (test_and_clear_bit(LED_SET_BRIGHTNESS, addr: &led_cdev->work_flags))
159 set_brightness_delayed_set_brightness(led_cdev, value: led_cdev->delayed_set_value);
160
161 if (test_and_clear_bit(LED_SET_BLINK, addr: &led_cdev->work_flags)) {
162 unsigned long delay_on = led_cdev->delayed_delay_on;
163 unsigned long delay_off = led_cdev->delayed_delay_off;
164
165 led_blink_set(led_cdev, delay_on: &delay_on, delay_off: &delay_off);
166 }
167}
168
169static void led_set_software_blink(struct led_classdev *led_cdev,
170 unsigned long delay_on,
171 unsigned long delay_off)
172{
173 int current_brightness;
174
175 current_brightness = led_get_brightness(led_cdev);
176 if (current_brightness)
177 led_cdev->blink_brightness = current_brightness;
178 if (!led_cdev->blink_brightness)
179 led_cdev->blink_brightness = led_cdev->max_brightness;
180
181 led_cdev->blink_delay_on = delay_on;
182 led_cdev->blink_delay_off = delay_off;
183
184 /* never on - just set to off */
185 if (!delay_on) {
186 led_set_brightness_nosleep(led_cdev, value: LED_OFF);
187 return;
188 }
189
190 /* never off - just set to brightness */
191 if (!delay_off) {
192 led_set_brightness_nosleep(led_cdev,
193 value: led_cdev->blink_brightness);
194 return;
195 }
196
197 set_bit(LED_BLINK_SW, addr: &led_cdev->work_flags);
198 mod_timer(timer: &led_cdev->blink_timer, expires: jiffies + 1);
199}
200
201
202static void led_blink_setup(struct led_classdev *led_cdev,
203 unsigned long *delay_on,
204 unsigned long *delay_off)
205{
206 if (!test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) &&
207 led_cdev->blink_set &&
208 !led_cdev->blink_set(led_cdev, delay_on, delay_off))
209 return;
210
211 /* blink with 1 Hz as default if nothing specified */
212 if (!*delay_on && !*delay_off)
213 *delay_on = *delay_off = 500;
214
215 led_set_software_blink(led_cdev, delay_on: *delay_on, delay_off: *delay_off);
216}
217
218void led_init_core(struct led_classdev *led_cdev)
219{
220 INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);
221
222 timer_setup(&led_cdev->blink_timer, led_timer_function, 0);
223}
224EXPORT_SYMBOL_GPL(led_init_core);
225
226void led_blink_set(struct led_classdev *led_cdev,
227 unsigned long *delay_on,
228 unsigned long *delay_off)
229{
230 del_timer_sync(timer: &led_cdev->blink_timer);
231
232 clear_bit(LED_BLINK_SW, addr: &led_cdev->work_flags);
233 clear_bit(LED_BLINK_ONESHOT, addr: &led_cdev->work_flags);
234 clear_bit(LED_BLINK_ONESHOT_STOP, addr: &led_cdev->work_flags);
235
236 led_blink_setup(led_cdev, delay_on, delay_off);
237}
238EXPORT_SYMBOL_GPL(led_blink_set);
239
240void led_blink_set_oneshot(struct led_classdev *led_cdev,
241 unsigned long *delay_on,
242 unsigned long *delay_off,
243 int invert)
244{
245 if (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) &&
246 timer_pending(timer: &led_cdev->blink_timer))
247 return;
248
249 set_bit(LED_BLINK_ONESHOT, addr: &led_cdev->work_flags);
250 clear_bit(LED_BLINK_ONESHOT_STOP, addr: &led_cdev->work_flags);
251
252 if (invert)
253 set_bit(LED_BLINK_INVERT, addr: &led_cdev->work_flags);
254 else
255 clear_bit(LED_BLINK_INVERT, addr: &led_cdev->work_flags);
256
257 led_blink_setup(led_cdev, delay_on, delay_off);
258}
259EXPORT_SYMBOL_GPL(led_blink_set_oneshot);
260
261void led_blink_set_nosleep(struct led_classdev *led_cdev, unsigned long delay_on,
262 unsigned long delay_off)
263{
264 /* If necessary delegate to a work queue task. */
265 if (led_cdev->blink_set && led_cdev->brightness_set_blocking) {
266 led_cdev->delayed_delay_on = delay_on;
267 led_cdev->delayed_delay_off = delay_off;
268 set_bit(LED_SET_BLINK, addr: &led_cdev->work_flags);
269 schedule_work(work: &led_cdev->set_brightness_work);
270 return;
271 }
272
273 led_blink_set(led_cdev, &delay_on, &delay_off);
274}
275EXPORT_SYMBOL_GPL(led_blink_set_nosleep);
276
277void led_stop_software_blink(struct led_classdev *led_cdev)
278{
279 del_timer_sync(timer: &led_cdev->blink_timer);
280 led_cdev->blink_delay_on = 0;
281 led_cdev->blink_delay_off = 0;
282 clear_bit(LED_BLINK_SW, addr: &led_cdev->work_flags);
283}
284EXPORT_SYMBOL_GPL(led_stop_software_blink);
285
286void led_set_brightness(struct led_classdev *led_cdev, unsigned int brightness)
287{
288 /*
289 * If software blink is active, delay brightness setting
290 * until the next timer tick.
291 */
292 if (test_bit(LED_BLINK_SW, &led_cdev->work_flags)) {
293 /*
294 * If we need to disable soft blinking delegate this to the
295 * work queue task to avoid problems in case we are called
296 * from hard irq context.
297 */
298 if (!brightness) {
299 set_bit(LED_BLINK_DISABLE, addr: &led_cdev->work_flags);
300 schedule_work(work: &led_cdev->set_brightness_work);
301 } else {
302 set_bit(LED_BLINK_BRIGHTNESS_CHANGE,
303 addr: &led_cdev->work_flags);
304 led_cdev->new_blink_brightness = brightness;
305 }
306 return;
307 }
308
309 led_set_brightness_nosleep(led_cdev, value: brightness);
310}
311EXPORT_SYMBOL_GPL(led_set_brightness);
312
313void led_set_brightness_nopm(struct led_classdev *led_cdev, unsigned int value)
314{
315 /* Use brightness_set op if available, it is guaranteed not to sleep */
316 if (!__led_set_brightness(led_cdev, value))
317 return;
318
319 /*
320 * Brightness setting can sleep, delegate it to a work queue task.
321 * value 0 / LED_OFF is special, since it also disables hw-blinking
322 * (sw-blink disable is handled in led_set_brightness()).
323 * To avoid a hw-blink-disable getting lost when a second brightness
324 * change is done immediately afterwards (before the work runs),
325 * it uses a separate work_flag.
326 */
327 if (value) {
328 led_cdev->delayed_set_value = value;
329 set_bit(LED_SET_BRIGHTNESS, addr: &led_cdev->work_flags);
330 } else {
331 clear_bit(LED_SET_BRIGHTNESS, addr: &led_cdev->work_flags);
332 clear_bit(LED_SET_BLINK, addr: &led_cdev->work_flags);
333 set_bit(LED_SET_BRIGHTNESS_OFF, addr: &led_cdev->work_flags);
334 }
335
336 schedule_work(work: &led_cdev->set_brightness_work);
337}
338EXPORT_SYMBOL_GPL(led_set_brightness_nopm);
339
340void led_set_brightness_nosleep(struct led_classdev *led_cdev, unsigned int value)
341{
342 led_cdev->brightness = min(value, led_cdev->max_brightness);
343
344 if (led_cdev->flags & LED_SUSPENDED)
345 return;
346
347 led_set_brightness_nopm(led_cdev, led_cdev->brightness);
348}
349EXPORT_SYMBOL_GPL(led_set_brightness_nosleep);
350
351int led_set_brightness_sync(struct led_classdev *led_cdev, unsigned int value)
352{
353 if (led_cdev->blink_delay_on || led_cdev->blink_delay_off)
354 return -EBUSY;
355
356 led_cdev->brightness = min(value, led_cdev->max_brightness);
357
358 if (led_cdev->flags & LED_SUSPENDED)
359 return 0;
360
361 return __led_set_brightness_blocking(led_cdev, value: led_cdev->brightness);
362}
363EXPORT_SYMBOL_GPL(led_set_brightness_sync);
364
365int led_update_brightness(struct led_classdev *led_cdev)
366{
367 int ret;
368
369 if (led_cdev->brightness_get) {
370 ret = led_cdev->brightness_get(led_cdev);
371 if (ret < 0)
372 return ret;
373
374 led_cdev->brightness = ret;
375 }
376
377 return 0;
378}
379EXPORT_SYMBOL_GPL(led_update_brightness);
380
381u32 *led_get_default_pattern(struct led_classdev *led_cdev, unsigned int *size)
382{
383 struct fwnode_handle *fwnode = led_cdev->dev->fwnode;
384 u32 *pattern;
385 int count;
386
387 count = fwnode_property_count_u32(fwnode, propname: "led-pattern");
388 if (count < 0)
389 return NULL;
390
391 pattern = kcalloc(n: count, size: sizeof(*pattern), GFP_KERNEL);
392 if (!pattern)
393 return NULL;
394
395 if (fwnode_property_read_u32_array(fwnode, propname: "led-pattern", val: pattern, nval: count)) {
396 kfree(objp: pattern);
397 return NULL;
398 }
399
400 *size = count;
401
402 return pattern;
403}
404EXPORT_SYMBOL_GPL(led_get_default_pattern);
405
406/* Caller must ensure led_cdev->led_access held */
407void led_sysfs_disable(struct led_classdev *led_cdev)
408{
409 lockdep_assert_held(&led_cdev->led_access);
410
411 led_cdev->flags |= LED_SYSFS_DISABLE;
412}
413EXPORT_SYMBOL_GPL(led_sysfs_disable);
414
415/* Caller must ensure led_cdev->led_access held */
416void led_sysfs_enable(struct led_classdev *led_cdev)
417{
418 lockdep_assert_held(&led_cdev->led_access);
419
420 led_cdev->flags &= ~LED_SYSFS_DISABLE;
421}
422EXPORT_SYMBOL_GPL(led_sysfs_enable);
423
424static void led_parse_fwnode_props(struct device *dev,
425 struct fwnode_handle *fwnode,
426 struct led_properties *props)
427{
428 int ret;
429
430 if (!fwnode)
431 return;
432
433 if (fwnode_property_present(fwnode, propname: "label")) {
434 ret = fwnode_property_read_string(fwnode, propname: "label", val: &props->label);
435 if (ret)
436 dev_err(dev, "Error parsing 'label' property (%d)\n", ret);
437 return;
438 }
439
440 if (fwnode_property_present(fwnode, propname: "color")) {
441 ret = fwnode_property_read_u32(fwnode, propname: "color", val: &props->color);
442 if (ret)
443 dev_err(dev, "Error parsing 'color' property (%d)\n", ret);
444 else if (props->color >= LED_COLOR_ID_MAX)
445 dev_err(dev, "LED color identifier out of range\n");
446 else
447 props->color_present = true;
448 }
449
450
451 if (!fwnode_property_present(fwnode, propname: "function"))
452 return;
453
454 ret = fwnode_property_read_string(fwnode, propname: "function", val: &props->function);
455 if (ret) {
456 dev_err(dev,
457 "Error parsing 'function' property (%d)\n",
458 ret);
459 }
460
461 if (!fwnode_property_present(fwnode, propname: "function-enumerator"))
462 return;
463
464 ret = fwnode_property_read_u32(fwnode, propname: "function-enumerator",
465 val: &props->func_enum);
466 if (ret) {
467 dev_err(dev,
468 "Error parsing 'function-enumerator' property (%d)\n",
469 ret);
470 } else {
471 props->func_enum_present = true;
472 }
473}
474
475int led_compose_name(struct device *dev, struct led_init_data *init_data,
476 char *led_classdev_name)
477{
478 struct led_properties props = {};
479 struct fwnode_handle *fwnode = init_data->fwnode;
480 const char *devicename = init_data->devicename;
481
482 if (!led_classdev_name)
483 return -EINVAL;
484
485 led_parse_fwnode_props(dev, fwnode, props: &props);
486
487 if (props.label) {
488 /*
489 * If init_data.devicename is NULL, then it indicates that
490 * DT label should be used as-is for LED class device name.
491 * Otherwise the label is prepended with devicename to compose
492 * the final LED class device name.
493 */
494 if (!devicename) {
495 strscpy(p: led_classdev_name, q: props.label,
496 LED_MAX_NAME_SIZE);
497 } else {
498 snprintf(buf: led_classdev_name, LED_MAX_NAME_SIZE, fmt: "%s:%s",
499 devicename, props.label);
500 }
501 } else if (props.function || props.color_present) {
502 char tmp_buf[LED_MAX_NAME_SIZE];
503
504 if (props.func_enum_present) {
505 snprintf(buf: tmp_buf, LED_MAX_NAME_SIZE, fmt: "%s:%s-%d",
506 props.color_present ? led_colors[props.color] : "",
507 props.function ?: "", props.func_enum);
508 } else {
509 snprintf(buf: tmp_buf, LED_MAX_NAME_SIZE, fmt: "%s:%s",
510 props.color_present ? led_colors[props.color] : "",
511 props.function ?: "");
512 }
513 if (init_data->devname_mandatory) {
514 snprintf(buf: led_classdev_name, LED_MAX_NAME_SIZE, fmt: "%s:%s",
515 devicename, tmp_buf);
516 } else {
517 strscpy(p: led_classdev_name, q: tmp_buf, LED_MAX_NAME_SIZE);
518
519 }
520 } else if (init_data->default_label) {
521 if (!devicename) {
522 dev_err(dev, "Legacy LED naming requires devicename segment");
523 return -EINVAL;
524 }
525 snprintf(buf: led_classdev_name, LED_MAX_NAME_SIZE, fmt: "%s:%s",
526 devicename, init_data->default_label);
527 } else if (is_of_node(fwnode)) {
528 strscpy(p: led_classdev_name, to_of_node(fwnode)->name,
529 LED_MAX_NAME_SIZE);
530 } else
531 return -EINVAL;
532
533 return 0;
534}
535EXPORT_SYMBOL_GPL(led_compose_name);
536
537enum led_default_state led_init_default_state_get(struct fwnode_handle *fwnode)
538{
539 const char *state = NULL;
540
541 if (!fwnode_property_read_string(fwnode, propname: "default-state", val: &state)) {
542 if (!strcmp(state, "keep"))
543 return LEDS_DEFSTATE_KEEP;
544 if (!strcmp(state, "on"))
545 return LEDS_DEFSTATE_ON;
546 }
547
548 return LEDS_DEFSTATE_OFF;
549}
550EXPORT_SYMBOL_GPL(led_init_default_state_get);
551

source code of linux/drivers/leds/led-core.c