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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 <[email protected]>
8 */
9
10#include <linux/kernel.h>
11#include <linux/led-class-multicolor.h>
12#include <linux/leds.h>
13#include <linux/list.h>
14#include <linux/module.h>
15#include <linux/mutex.h>
16#include <linux/of.h>
17#include <linux/property.h>
18#include <linux/rwsem.h>
19#include <linux/slab.h>
20#include <uapi/linux/uleds.h>
21#include "leds.h"
22
23DECLARE_RWSEM(leds_list_lock);
24EXPORT_SYMBOL_GPL(leds_list_lock);
25
26LIST_HEAD(leds_list);
27EXPORT_SYMBOL_GPL(leds_list);
28
29static const char * const led_colors[LED_COLOR_ID_MAX] = {
30 [LED_COLOR_ID_WHITE] = "white",
31 [LED_COLOR_ID_RED] = "red",
32 [LED_COLOR_ID_GREEN] = "green",
33 [LED_COLOR_ID_BLUE] = "blue",
34 [LED_COLOR_ID_AMBER] = "amber",
35 [LED_COLOR_ID_VIOLET] = "violet",
36 [LED_COLOR_ID_YELLOW] = "yellow",
37 [LED_COLOR_ID_IR] = "ir",
38 [LED_COLOR_ID_MULTI] = "multicolor",
39 [LED_COLOR_ID_RGB] = "rgb",
40 [LED_COLOR_ID_PURPLE] = "purple",
41 [LED_COLOR_ID_ORANGE] = "orange",
42 [LED_COLOR_ID_PINK] = "pink",
43 [LED_COLOR_ID_CYAN] = "cyan",
44 [LED_COLOR_ID_LIME] = "lime",
45};
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 = timer_container_of(led_cdev, t,
68 blink_timer);
69 unsigned long brightness;
70 unsigned long delay;
71
72 if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) {
73 led_set_brightness_nosleep(led_cdev, LED_OFF);
74 clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
75 return;
76 }
77
78 if (test_and_clear_bit(LED_BLINK_ONESHOT_STOP,
79 &led_cdev->work_flags)) {
80 clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
81 return;
82 }
83
84 brightness = led_get_brightness(led_cdev);
85 if (!brightness) {
86 /* Time to switch the LED on. */
87 if (test_and_clear_bit(LED_BLINK_BRIGHTNESS_CHANGE,
88 &led_cdev->work_flags))
89 brightness = led_cdev->new_blink_brightness;
90 else
91 brightness = led_cdev->blink_brightness;
92 delay = led_cdev->blink_delay_on;
93 } else {
94 /* Store the current brightness value to be able
95 * to restore it when the delay_off period is over.
96 */
97 led_cdev->blink_brightness = brightness;
98 brightness = LED_OFF;
99 delay = led_cdev->blink_delay_off;
100 }
101
102 led_set_brightness_nosleep(led_cdev, brightness);
103
104 /* Return in next iteration if led is in one-shot mode and we are in
105 * the final blink state so that the led is toggled each delay_on +
106 * delay_off milliseconds in worst case.
107 */
108 if (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags)) {
109 if (test_bit(LED_BLINK_INVERT, &led_cdev->work_flags)) {
110 if (brightness)
111 set_bit(LED_BLINK_ONESHOT_STOP,
112 &led_cdev->work_flags);
113 } else {
114 if (!brightness)
115 set_bit(LED_BLINK_ONESHOT_STOP,
116 &led_cdev->work_flags);
117 }
118 }
119
120 mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
121}
122
123static void set_brightness_delayed_set_brightness(struct led_classdev *led_cdev,
124 unsigned int value)
125{
126 int ret;
127
128 ret = __led_set_brightness(led_cdev, value);
129 if (ret == -ENOTSUPP) {
130 ret = __led_set_brightness_blocking(led_cdev, value);
131 if (ret == -ENOTSUPP)
132 /* No back-end support to set a fixed brightness value */
133 return;
134 }
135
136 /* LED HW might have been unplugged, therefore don't warn */
137 if (ret == -ENODEV && led_cdev->flags & LED_UNREGISTERING &&
138 led_cdev->flags & LED_HW_PLUGGABLE)
139 return;
140
141 if (ret < 0)
142 dev_err(led_cdev->dev,
143 "Setting an LED's brightness failed (%d)\n", ret);
144}
145
146static void set_brightness_delayed(struct work_struct *ws)
147{
148 struct led_classdev *led_cdev =
149 container_of(ws, struct led_classdev, set_brightness_work);
150
151 if (test_and_clear_bit(LED_BLINK_DISABLE, &led_cdev->work_flags)) {
152 led_stop_software_blink(led_cdev);
153 set_bit(LED_SET_BRIGHTNESS_OFF, &led_cdev->work_flags);
154 }
155
156 /*
157 * Triggers may call led_set_brightness(LED_OFF),
158 * led_set_brightness(LED_FULL) in quick succession to disable blinking
159 * and turn the LED on. Both actions may have been scheduled to run
160 * before this work item runs once. To make sure this works properly
161 * handle LED_SET_BRIGHTNESS_OFF first.
162 */
163 if (test_and_clear_bit(LED_SET_BRIGHTNESS_OFF, &led_cdev->work_flags)) {
164 set_brightness_delayed_set_brightness(led_cdev, LED_OFF);
165 /*
166 * The consecutives led_set_brightness(LED_OFF),
167 * led_set_brightness(LED_FULL) could have been executed out of
168 * order (LED_FULL first), if the work_flags has been set
169 * between LED_SET_BRIGHTNESS_OFF and LED_SET_BRIGHTNESS of this
170 * work. To avoid ending with the LED turned off, turn the LED
171 * on again.
172 */
173 if (led_cdev->delayed_set_value != LED_OFF)
174 set_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags);
175 }
176
177 if (test_and_clear_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags))
178 set_brightness_delayed_set_brightness(led_cdev, led_cdev->delayed_set_value);
179
180 if (test_and_clear_bit(LED_SET_BLINK, &led_cdev->work_flags)) {
181 unsigned long delay_on = led_cdev->delayed_delay_on;
182 unsigned long delay_off = led_cdev->delayed_delay_off;
183
184 led_blink_set(led_cdev, &delay_on, &delay_off);
185 }
186}
187
188static void led_set_software_blink(struct led_classdev *led_cdev,
189 unsigned long delay_on,
190 unsigned long delay_off)
191{
192 int current_brightness;
193
194 current_brightness = led_get_brightness(led_cdev);
195 if (current_brightness)
196 led_cdev->blink_brightness = current_brightness;
197 if (!led_cdev->blink_brightness)
198 led_cdev->blink_brightness = led_cdev->max_brightness;
199
200 led_cdev->blink_delay_on = delay_on;
201 led_cdev->blink_delay_off = delay_off;
202
203 /* never on - just set to off */
204 if (!delay_on) {
205 led_set_brightness_nosleep(led_cdev, LED_OFF);
206 return;
207 }
208
209 /* never off - just set to brightness */
210 if (!delay_off) {
211 led_set_brightness_nosleep(led_cdev,
212 led_cdev->blink_brightness);
213 return;
214 }
215
216 set_bit(LED_BLINK_SW, &led_cdev->work_flags);
217 mod_timer(&led_cdev->blink_timer, jiffies + 1);
218}
219
220static void led_blink_setup(struct led_classdev *led_cdev,
221 unsigned long *delay_on,
222 unsigned long *delay_off)
223{
224 if (!test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) &&
225 led_cdev->blink_set &&
226 !led_cdev->blink_set(led_cdev, delay_on, delay_off))
227 return;
228
229 /* blink with 1 Hz as default if nothing specified */
230 if (!*delay_on && !*delay_off)
231 *delay_on = *delay_off = 500;
232
233 led_set_software_blink(led_cdev, *delay_on, *delay_off);
234}
235
236void led_init_core(struct led_classdev *led_cdev)
237{
238 INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);
239
240 timer_setup(&led_cdev->blink_timer, led_timer_function, 0);
241}
242EXPORT_SYMBOL_GPL(led_init_core);
243
244void led_blink_set(struct led_classdev *led_cdev,
245 unsigned long *delay_on,
246 unsigned long *delay_off)
247{
248 timer_delete_sync(&led_cdev->blink_timer);
249
250 clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
251 clear_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags);
252 clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags);
253
254 led_blink_setup(led_cdev, delay_on, delay_off);
255}
256EXPORT_SYMBOL_GPL(led_blink_set);
257
258void led_blink_set_oneshot(struct led_classdev *led_cdev,
259 unsigned long *delay_on,
260 unsigned long *delay_off,
261 int invert)
262{
263 if (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) &&
264 timer_pending(&led_cdev->blink_timer))
265 return;
266
267 set_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags);
268 clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags);
269
270 if (invert)
271 set_bit(LED_BLINK_INVERT, &led_cdev->work_flags);
272 else
273 clear_bit(LED_BLINK_INVERT, &led_cdev->work_flags);
274
275 led_blink_setup(led_cdev, delay_on, delay_off);
276}
277EXPORT_SYMBOL_GPL(led_blink_set_oneshot);
278
279void led_blink_set_nosleep(struct led_classdev *led_cdev, unsigned long delay_on,
280 unsigned long delay_off)
281{
282 /* If necessary delegate to a work queue task. */
283 if (led_cdev->blink_set && led_cdev->brightness_set_blocking) {
284 led_cdev->delayed_delay_on = delay_on;
285 led_cdev->delayed_delay_off = delay_off;
286 set_bit(LED_SET_BLINK, &led_cdev->work_flags);
287 queue_work(led_cdev->wq, &led_cdev->set_brightness_work);
288 return;
289 }
290
291 led_blink_set(led_cdev, &delay_on, &delay_off);
292}
293EXPORT_SYMBOL_GPL(led_blink_set_nosleep);
294
295void led_stop_software_blink(struct led_classdev *led_cdev)
296{
297 timer_delete_sync(&led_cdev->blink_timer);
298 led_cdev->blink_delay_on = 0;
299 led_cdev->blink_delay_off = 0;
300 clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
301}
302EXPORT_SYMBOL_GPL(led_stop_software_blink);
303
304void led_set_brightness(struct led_classdev *led_cdev, unsigned int brightness)
305{
306 if (brightness) {
307 /*
308 * If software blink disable is pending, also queue brightness setting.
309 * If software blink is active, delay brightness setting
310 * until the next timer tick.
311 */
312 if (test_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags) ||
313 test_bit(LED_BLINK_DISABLE, &led_cdev->work_flags)) {
314 led_cdev->delayed_set_value = brightness;
315 set_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags);
316 queue_work(led_cdev->wq, &led_cdev->set_brightness_work);
317 return;
318 } else if (test_bit(LED_BLINK_SW, &led_cdev->work_flags)) {
319 led_cdev->new_blink_brightness = brightness;
320 set_bit(LED_BLINK_BRIGHTNESS_CHANGE, &led_cdev->work_flags);
321 return;
322 }
323 } else if (test_bit(LED_BLINK_SW, &led_cdev->work_flags)) {
324 /*
325 * If we need to disable soft blinking delegate this to the
326 * work queue task to avoid problems in case we are called
327 * from hard irq context.
328 */
329 set_bit(LED_BLINK_DISABLE, &led_cdev->work_flags);
330 queue_work(led_cdev->wq, &led_cdev->set_brightness_work);
331 return;
332 }
333
334 led_set_brightness_nosleep(led_cdev, brightness);
335}
336EXPORT_SYMBOL_GPL(led_set_brightness);
337
338void led_set_brightness_nopm(struct led_classdev *led_cdev, unsigned int value)
339{
340 /* Use brightness_set op if available, it is guaranteed not to sleep */
341 if (!__led_set_brightness(led_cdev, value))
342 return;
343
344 /*
345 * Brightness setting can sleep, delegate it to a work queue task.
346 * value 0 / LED_OFF is special, since it also disables hw-blinking
347 * (sw-blink disable is handled in led_set_brightness()).
348 * To avoid a hw-blink-disable getting lost when a second brightness
349 * change is done immediately afterwards (before the work runs),
350 * it uses a separate work_flag.
351 */
352 led_cdev->delayed_set_value = value;
353 /* Ensure delayed_set_value is seen before work_flags modification */
354 smp_mb__before_atomic();
355
356 if (value) {
357 set_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags);
358 } else {
359 clear_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags);
360 clear_bit(LED_SET_BLINK, &led_cdev->work_flags);
361 set_bit(LED_SET_BRIGHTNESS_OFF, &led_cdev->work_flags);
362 }
363
364 queue_work(led_cdev->wq, &led_cdev->set_brightness_work);
365}
366EXPORT_SYMBOL_GPL(led_set_brightness_nopm);
367
368void led_set_brightness_nosleep(struct led_classdev *led_cdev, unsigned int value)
369{
370 led_cdev->brightness = min(value, led_cdev->max_brightness);
371
372 if (led_cdev->flags & LED_SUSPENDED)
373 return;
374
375 led_set_brightness_nopm(led_cdev, led_cdev->brightness);
376}
377EXPORT_SYMBOL_GPL(led_set_brightness_nosleep);
378
379int led_set_brightness_sync(struct led_classdev *led_cdev, unsigned int value)
380{
381 if (led_cdev->blink_delay_on || led_cdev->blink_delay_off)
382 return -EBUSY;
383
384 led_cdev->brightness = min(value, led_cdev->max_brightness);
385
386 if (led_cdev->flags & LED_SUSPENDED)
387 return 0;
388
389 return __led_set_brightness_blocking(led_cdev, led_cdev->brightness);
390}
391EXPORT_SYMBOL_GPL(led_set_brightness_sync);
392
393/*
394 * This is a led-core function because just like led_set_brightness()
395 * it is used in the kernel by e.g. triggers.
396 */
397void led_mc_set_brightness(struct led_classdev *led_cdev,
398 unsigned int *intensity_value, unsigned int num_colors,
399 unsigned int brightness)
400{
401 struct led_classdev_mc *mcled_cdev;
402 unsigned int i;
403
404 if (!(led_cdev->flags & LED_MULTI_COLOR)) {
405 dev_err_once(led_cdev->dev, "error not a multi-color LED\n");
406 return;
407 }
408
409 mcled_cdev = lcdev_to_mccdev(led_cdev);
410 if (num_colors != mcled_cdev->num_colors) {
411 dev_err_once(led_cdev->dev, "error num_colors mismatch %u != %u\n",
412 num_colors, mcled_cdev->num_colors);
413 return;
414 }
415
416 for (i = 0; i < mcled_cdev->num_colors; i++)
417 mcled_cdev->subled_info[i].intensity = intensity_value[i];
418
419 led_set_brightness(led_cdev, brightness);
420}
421EXPORT_SYMBOL_GPL(led_mc_set_brightness);
422
423int led_update_brightness(struct led_classdev *led_cdev)
424{
425 int ret;
426
427 if (led_cdev->brightness_get) {
428 ret = led_cdev->brightness_get(led_cdev);
429 if (ret < 0)
430 return ret;
431
432 led_cdev->brightness = ret;
433 }
434
435 return 0;
436}
437EXPORT_SYMBOL_GPL(led_update_brightness);
438
439u32 *led_get_default_pattern(struct led_classdev *led_cdev, unsigned int *size)
440{
441 struct fwnode_handle *fwnode = led_cdev->dev->fwnode;
442 u32 *pattern;
443 int count;
444
445 count = fwnode_property_count_u32(fwnode, "led-pattern");
446 if (count < 0)
447 return NULL;
448
449 pattern = kcalloc(count, sizeof(*pattern), GFP_KERNEL);
450 if (!pattern)
451 return NULL;
452
453 if (fwnode_property_read_u32_array(fwnode, "led-pattern", pattern, count)) {
454 kfree(pattern);
455 return NULL;
456 }
457
458 *size = count;
459
460 return pattern;
461}
462EXPORT_SYMBOL_GPL(led_get_default_pattern);
463
464/* Caller must ensure led_cdev->led_access held */
465void led_sysfs_disable(struct led_classdev *led_cdev)
466{
467 lockdep_assert_held(&led_cdev->led_access);
468
469 led_cdev->flags |= LED_SYSFS_DISABLE;
470}
471EXPORT_SYMBOL_GPL(led_sysfs_disable);
472
473/* Caller must ensure led_cdev->led_access held */
474void led_sysfs_enable(struct led_classdev *led_cdev)
475{
476 lockdep_assert_held(&led_cdev->led_access);
477
478 led_cdev->flags &= ~LED_SYSFS_DISABLE;
479}
480EXPORT_SYMBOL_GPL(led_sysfs_enable);
481
482static void led_parse_fwnode_props(struct device *dev,
483 struct fwnode_handle *fwnode,
484 struct led_properties *props)
485{
486 int ret;
487
488 if (!fwnode)
489 return;
490
491 if (fwnode_property_present(fwnode, "label")) {
492 ret = fwnode_property_read_string(fwnode, "label", &props->label);
493 if (ret)
494 dev_err(dev, "Error parsing 'label' property (%d)\n", ret);
495 return;
496 }
497
498 if (fwnode_property_present(fwnode, "color")) {
499 ret = fwnode_property_read_u32(fwnode, "color", &props->color);
500 if (ret)
501 dev_err(dev, "Error parsing 'color' property (%d)\n", ret);
502 else if (props->color >= LED_COLOR_ID_MAX)
503 dev_err(dev, "LED color identifier out of range\n");
504 else
505 props->color_present = true;
506 }
507
508 if (!fwnode_property_present(fwnode, "function"))
509 return;
510
511 ret = fwnode_property_read_string(fwnode, "function", &props->function);
512 if (ret) {
513 dev_err(dev,
514 "Error parsing 'function' property (%d)\n",
515 ret);
516 }
517
518 if (!fwnode_property_present(fwnode, "function-enumerator"))
519 return;
520
521 ret = fwnode_property_read_u32(fwnode, "function-enumerator",
522 &props->func_enum);
523 if (ret) {
524 dev_err(dev,
525 "Error parsing 'function-enumerator' property (%d)\n",
526 ret);
527 } else {
528 props->func_enum_present = true;
529 }
530}
531
532int led_compose_name(struct device *dev, struct led_init_data *init_data,
533 char *led_classdev_name)
534{
535 struct led_properties props = {};
536 struct fwnode_handle *fwnode = init_data->fwnode;
537 const char *devicename = init_data->devicename;
538 int n;
539
540 if (!led_classdev_name)
541 return -EINVAL;
542
543 led_parse_fwnode_props(dev, fwnode, &props);
544
545 if (props.label) {
546 /*
547 * If init_data.devicename is NULL, then it indicates that
548 * DT label should be used as-is for LED class device name.
549 * Otherwise the label is prepended with devicename to compose
550 * the final LED class device name.
551 */
552 if (devicename) {
553 n = snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s",
554 devicename, props.label);
555 } else {
556 n = snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s", props.label);
557 }
558 } else if (props.function || props.color_present) {
559 char tmp_buf[LED_MAX_NAME_SIZE];
560
561 if (props.func_enum_present) {
562 n = snprintf(tmp_buf, LED_MAX_NAME_SIZE, "%s:%s-%d",
563 props.color_present ? led_colors[props.color] : "",
564 props.function ?: "", props.func_enum);
565 } else {
566 n = snprintf(tmp_buf, LED_MAX_NAME_SIZE, "%s:%s",
567 props.color_present ? led_colors[props.color] : "",
568 props.function ?: "");
569 }
570 if (n >= LED_MAX_NAME_SIZE)
571 return -E2BIG;
572
573 if (init_data->devname_mandatory) {
574 n = snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s",
575 devicename, tmp_buf);
576 } else {
577 n = snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s", tmp_buf);
578 }
579 } else if (init_data->default_label) {
580 if (!devicename) {
581 dev_err(dev, "Legacy LED naming requires devicename segment");
582 return -EINVAL;
583 }
584 n = snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s",
585 devicename, init_data->default_label);
586 } else if (is_of_node(fwnode)) {
587 n = snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s",
588 to_of_node(fwnode)->name);
589 } else if (is_software_node(fwnode)) {
590 n = snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s",
591 fwnode_get_name(fwnode));
592 } else {
593 return -EINVAL;
594 }
595
596 if (n >= LED_MAX_NAME_SIZE)
597 return -E2BIG;
598
599 return 0;
600}
601EXPORT_SYMBOL_GPL(led_compose_name);
602
603const char *led_get_color_name(u8 color_id)
604{
605 if (color_id >= ARRAY_SIZE(led_colors))
606 return NULL;
607
608 return led_colors[color_id];
609}
610EXPORT_SYMBOL_GPL(led_get_color_name);
611
612enum led_default_state led_init_default_state_get(struct fwnode_handle *fwnode)
613{
614 const char *state = NULL;
615
616 if (!fwnode_property_read_string(fwnode, "default-state", &state)) {
617 if (!strcmp(state, "keep"))
618 return LEDS_DEFSTATE_KEEP;
619 if (!strcmp(state, "on"))
620 return LEDS_DEFSTATE_ON;
621 }
622
623 return LEDS_DEFSTATE_OFF;
624}
625EXPORT_SYMBOL_GPL(led_init_default_state_get);