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/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, value: LED_OFF);
74 clear_bit(LED_BLINK_SW, addr: &led_cdev->work_flags);
75 return;
76 }
77
78 if (test_and_clear_bit(LED_BLINK_ONESHOT_STOP,
79 addr: &led_cdev->work_flags)) {
80 clear_bit(LED_BLINK_SW, addr: &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 addr: &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, value: 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 addr: &led_cdev->work_flags);
113 } else {
114 if (!brightness)
115 set_bit(LED_BLINK_ONESHOT_STOP,
116 addr: &led_cdev->work_flags);
117 }
118 }
119
120 mod_timer(timer: &led_cdev->blink_timer, expires: jiffies + msecs_to_jiffies(m: 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, addr: &led_cdev->work_flags)) {
152 led_stop_software_blink(led_cdev);
153 set_bit(LED_SET_BRIGHTNESS_OFF, addr: &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, addr: &led_cdev->work_flags)) {
164 set_brightness_delayed_set_brightness(led_cdev, value: 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, addr: &led_cdev->work_flags);
175 }
176
177 if (test_and_clear_bit(LED_SET_BRIGHTNESS, addr: &led_cdev->work_flags))
178 set_brightness_delayed_set_brightness(led_cdev, value: led_cdev->delayed_set_value);
179
180 if (test_and_clear_bit(LED_SET_BLINK, addr: &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_on, delay_off: &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, value: 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 value: led_cdev->blink_brightness);
213 return;
214 }
215
216 set_bit(LED_BLINK_SW, addr: &led_cdev->work_flags);
217 mod_timer(timer: &led_cdev->blink_timer, expires: jiffies + 1);
218}
219
220
221static void led_blink_setup(struct led_classdev *led_cdev,
222 unsigned long *delay_on,
223 unsigned long *delay_off)
224{
225 if (!test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) &&
226 led_cdev->blink_set &&
227 !led_cdev->blink_set(led_cdev, delay_on, delay_off))
228 return;
229
230 /* blink with 1 Hz as default if nothing specified */
231 if (!*delay_on && !*delay_off)
232 *delay_on = *delay_off = 500;
233
234 led_set_software_blink(led_cdev, delay_on: *delay_on, delay_off: *delay_off);
235}
236
237void led_init_core(struct led_classdev *led_cdev)
238{
239 INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);
240
241 timer_setup(&led_cdev->blink_timer, led_timer_function, 0);
242}
243EXPORT_SYMBOL_GPL(led_init_core);
244
245void led_blink_set(struct led_classdev *led_cdev,
246 unsigned long *delay_on,
247 unsigned long *delay_off)
248{
249 timer_delete_sync(timer: &led_cdev->blink_timer);
250
251 clear_bit(LED_BLINK_SW, addr: &led_cdev->work_flags);
252 clear_bit(LED_BLINK_ONESHOT, addr: &led_cdev->work_flags);
253 clear_bit(LED_BLINK_ONESHOT_STOP, addr: &led_cdev->work_flags);
254
255 led_blink_setup(led_cdev, delay_on, delay_off);
256}
257EXPORT_SYMBOL_GPL(led_blink_set);
258
259void led_blink_set_oneshot(struct led_classdev *led_cdev,
260 unsigned long *delay_on,
261 unsigned long *delay_off,
262 int invert)
263{
264 if (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) &&
265 timer_pending(timer: &led_cdev->blink_timer))
266 return;
267
268 set_bit(LED_BLINK_ONESHOT, addr: &led_cdev->work_flags);
269 clear_bit(LED_BLINK_ONESHOT_STOP, addr: &led_cdev->work_flags);
270
271 if (invert)
272 set_bit(LED_BLINK_INVERT, addr: &led_cdev->work_flags);
273 else
274 clear_bit(LED_BLINK_INVERT, addr: &led_cdev->work_flags);
275
276 led_blink_setup(led_cdev, delay_on, delay_off);
277}
278EXPORT_SYMBOL_GPL(led_blink_set_oneshot);
279
280void led_blink_set_nosleep(struct led_classdev *led_cdev, unsigned long delay_on,
281 unsigned long delay_off)
282{
283 /* If necessary delegate to a work queue task. */
284 if (led_cdev->blink_set && led_cdev->brightness_set_blocking) {
285 led_cdev->delayed_delay_on = delay_on;
286 led_cdev->delayed_delay_off = delay_off;
287 set_bit(LED_SET_BLINK, addr: &led_cdev->work_flags);
288 queue_work(wq: led_cdev->wq, work: &led_cdev->set_brightness_work);
289 return;
290 }
291
292 led_blink_set(led_cdev, &delay_on, &delay_off);
293}
294EXPORT_SYMBOL_GPL(led_blink_set_nosleep);
295
296void led_stop_software_blink(struct led_classdev *led_cdev)
297{
298 timer_delete_sync(timer: &led_cdev->blink_timer);
299 led_cdev->blink_delay_on = 0;
300 led_cdev->blink_delay_off = 0;
301 clear_bit(LED_BLINK_SW, addr: &led_cdev->work_flags);
302}
303EXPORT_SYMBOL_GPL(led_stop_software_blink);
304
305void led_set_brightness(struct led_classdev *led_cdev, unsigned int brightness)
306{
307 /*
308 * If software blink is active, delay brightness setting
309 * until the next timer tick.
310 */
311 if (test_bit(LED_BLINK_SW, &led_cdev->work_flags)) {
312 /*
313 * If we need to disable soft blinking delegate this to the
314 * work queue task to avoid problems in case we are called
315 * from hard irq context.
316 */
317 if (!brightness) {
318 set_bit(LED_BLINK_DISABLE, addr: &led_cdev->work_flags);
319 queue_work(wq: led_cdev->wq, work: &led_cdev->set_brightness_work);
320 } else {
321 set_bit(LED_BLINK_BRIGHTNESS_CHANGE,
322 addr: &led_cdev->work_flags);
323 led_cdev->new_blink_brightness = brightness;
324 }
325 return;
326 }
327
328 led_set_brightness_nosleep(led_cdev, value: brightness);
329}
330EXPORT_SYMBOL_GPL(led_set_brightness);
331
332void led_set_brightness_nopm(struct led_classdev *led_cdev, unsigned int value)
333{
334 /* Use brightness_set op if available, it is guaranteed not to sleep */
335 if (!__led_set_brightness(led_cdev, value))
336 return;
337
338 /*
339 * Brightness setting can sleep, delegate it to a work queue task.
340 * value 0 / LED_OFF is special, since it also disables hw-blinking
341 * (sw-blink disable is handled in led_set_brightness()).
342 * To avoid a hw-blink-disable getting lost when a second brightness
343 * change is done immediately afterwards (before the work runs),
344 * it uses a separate work_flag.
345 */
346 led_cdev->delayed_set_value = value;
347 /* Ensure delayed_set_value is seen before work_flags modification */
348 smp_mb__before_atomic();
349
350 if (value)
351 set_bit(LED_SET_BRIGHTNESS, addr: &led_cdev->work_flags);
352 else {
353 clear_bit(LED_SET_BRIGHTNESS, addr: &led_cdev->work_flags);
354 clear_bit(LED_SET_BLINK, addr: &led_cdev->work_flags);
355 set_bit(LED_SET_BRIGHTNESS_OFF, addr: &led_cdev->work_flags);
356 }
357
358 queue_work(wq: led_cdev->wq, work: &led_cdev->set_brightness_work);
359}
360EXPORT_SYMBOL_GPL(led_set_brightness_nopm);
361
362void led_set_brightness_nosleep(struct led_classdev *led_cdev, unsigned int value)
363{
364 led_cdev->brightness = min(value, led_cdev->max_brightness);
365
366 if (led_cdev->flags & LED_SUSPENDED)
367 return;
368
369 led_set_brightness_nopm(led_cdev, led_cdev->brightness);
370}
371EXPORT_SYMBOL_GPL(led_set_brightness_nosleep);
372
373int led_set_brightness_sync(struct led_classdev *led_cdev, unsigned int value)
374{
375 if (led_cdev->blink_delay_on || led_cdev->blink_delay_off)
376 return -EBUSY;
377
378 led_cdev->brightness = min(value, led_cdev->max_brightness);
379
380 if (led_cdev->flags & LED_SUSPENDED)
381 return 0;
382
383 return __led_set_brightness_blocking(led_cdev, value: led_cdev->brightness);
384}
385EXPORT_SYMBOL_GPL(led_set_brightness_sync);
386
387/*
388 * This is a led-core function because just like led_set_brightness()
389 * it is used in the kernel by e.g. triggers.
390 */
391void led_mc_set_brightness(struct led_classdev *led_cdev,
392 unsigned int *intensity_value, unsigned int num_colors,
393 unsigned int brightness)
394{
395 struct led_classdev_mc *mcled_cdev;
396 unsigned int i;
397
398 if (!(led_cdev->flags & LED_MULTI_COLOR)) {
399 dev_err_once(led_cdev->dev, "error not a multi-color LED\n");
400 return;
401 }
402
403 mcled_cdev = lcdev_to_mccdev(led_cdev);
404 if (num_colors != mcled_cdev->num_colors) {
405 dev_err_once(led_cdev->dev, "error num_colors mismatch %u != %u\n",
406 num_colors, mcled_cdev->num_colors);
407 return;
408 }
409
410 for (i = 0; i < mcled_cdev->num_colors; i++)
411 mcled_cdev->subled_info[i].intensity = intensity_value[i];
412
413 led_set_brightness(led_cdev, brightness);
414}
415EXPORT_SYMBOL_GPL(led_mc_set_brightness);
416
417int led_update_brightness(struct led_classdev *led_cdev)
418{
419 int ret;
420
421 if (led_cdev->brightness_get) {
422 ret = led_cdev->brightness_get(led_cdev);
423 if (ret < 0)
424 return ret;
425
426 led_cdev->brightness = ret;
427 }
428
429 return 0;
430}
431EXPORT_SYMBOL_GPL(led_update_brightness);
432
433u32 *led_get_default_pattern(struct led_classdev *led_cdev, unsigned int *size)
434{
435 struct fwnode_handle *fwnode = led_cdev->dev->fwnode;
436 u32 *pattern;
437 int count;
438
439 count = fwnode_property_count_u32(fwnode, propname: "led-pattern");
440 if (count < 0)
441 return NULL;
442
443 pattern = kcalloc(count, sizeof(*pattern), GFP_KERNEL);
444 if (!pattern)
445 return NULL;
446
447 if (fwnode_property_read_u32_array(fwnode, propname: "led-pattern", val: pattern, nval: count)) {
448 kfree(objp: pattern);
449 return NULL;
450 }
451
452 *size = count;
453
454 return pattern;
455}
456EXPORT_SYMBOL_GPL(led_get_default_pattern);
457
458/* Caller must ensure led_cdev->led_access held */
459void led_sysfs_disable(struct led_classdev *led_cdev)
460{
461 lockdep_assert_held(&led_cdev->led_access);
462
463 led_cdev->flags |= LED_SYSFS_DISABLE;
464}
465EXPORT_SYMBOL_GPL(led_sysfs_disable);
466
467/* Caller must ensure led_cdev->led_access held */
468void led_sysfs_enable(struct led_classdev *led_cdev)
469{
470 lockdep_assert_held(&led_cdev->led_access);
471
472 led_cdev->flags &= ~LED_SYSFS_DISABLE;
473}
474EXPORT_SYMBOL_GPL(led_sysfs_enable);
475
476static void led_parse_fwnode_props(struct device *dev,
477 struct fwnode_handle *fwnode,
478 struct led_properties *props)
479{
480 int ret;
481
482 if (!fwnode)
483 return;
484
485 if (fwnode_property_present(fwnode, propname: "label")) {
486 ret = fwnode_property_read_string(fwnode, propname: "label", val: &props->label);
487 if (ret)
488 dev_err(dev, "Error parsing 'label' property (%d)\n", ret);
489 return;
490 }
491
492 if (fwnode_property_present(fwnode, propname: "color")) {
493 ret = fwnode_property_read_u32(fwnode, propname: "color", val: &props->color);
494 if (ret)
495 dev_err(dev, "Error parsing 'color' property (%d)\n", ret);
496 else if (props->color >= LED_COLOR_ID_MAX)
497 dev_err(dev, "LED color identifier out of range\n");
498 else
499 props->color_present = true;
500 }
501
502
503 if (!fwnode_property_present(fwnode, propname: "function"))
504 return;
505
506 ret = fwnode_property_read_string(fwnode, propname: "function", val: &props->function);
507 if (ret) {
508 dev_err(dev,
509 "Error parsing 'function' property (%d)\n",
510 ret);
511 }
512
513 if (!fwnode_property_present(fwnode, propname: "function-enumerator"))
514 return;
515
516 ret = fwnode_property_read_u32(fwnode, propname: "function-enumerator",
517 val: &props->func_enum);
518 if (ret) {
519 dev_err(dev,
520 "Error parsing 'function-enumerator' property (%d)\n",
521 ret);
522 } else {
523 props->func_enum_present = true;
524 }
525}
526
527int led_compose_name(struct device *dev, struct led_init_data *init_data,
528 char *led_classdev_name)
529{
530 struct led_properties props = {};
531 struct fwnode_handle *fwnode = init_data->fwnode;
532 const char *devicename = init_data->devicename;
533 int n;
534
535 if (!led_classdev_name)
536 return -EINVAL;
537
538 led_parse_fwnode_props(dev, fwnode, props: &props);
539
540 if (props.label) {
541 /*
542 * If init_data.devicename is NULL, then it indicates that
543 * DT label should be used as-is for LED class device name.
544 * Otherwise the label is prepended with devicename to compose
545 * the final LED class device name.
546 */
547 if (devicename) {
548 n = snprintf(buf: led_classdev_name, LED_MAX_NAME_SIZE, fmt: "%s:%s",
549 devicename, props.label);
550 } else {
551 n = snprintf(buf: led_classdev_name, LED_MAX_NAME_SIZE, fmt: "%s", props.label);
552 }
553 } else if (props.function || props.color_present) {
554 char tmp_buf[LED_MAX_NAME_SIZE];
555
556 if (props.func_enum_present) {
557 n = snprintf(buf: tmp_buf, LED_MAX_NAME_SIZE, fmt: "%s:%s-%d",
558 props.color_present ? led_colors[props.color] : "",
559 props.function ?: "", props.func_enum);
560 } else {
561 n = snprintf(buf: tmp_buf, LED_MAX_NAME_SIZE, fmt: "%s:%s",
562 props.color_present ? led_colors[props.color] : "",
563 props.function ?: "");
564 }
565 if (n >= LED_MAX_NAME_SIZE)
566 return -E2BIG;
567
568 if (init_data->devname_mandatory) {
569 n = snprintf(buf: led_classdev_name, LED_MAX_NAME_SIZE, fmt: "%s:%s",
570 devicename, tmp_buf);
571 } else {
572 n = snprintf(buf: led_classdev_name, LED_MAX_NAME_SIZE, fmt: "%s", tmp_buf);
573 }
574 } else if (init_data->default_label) {
575 if (!devicename) {
576 dev_err(dev, "Legacy LED naming requires devicename segment");
577 return -EINVAL;
578 }
579 n = snprintf(buf: led_classdev_name, LED_MAX_NAME_SIZE, fmt: "%s:%s",
580 devicename, init_data->default_label);
581 } else if (is_of_node(fwnode)) {
582 n = snprintf(buf: led_classdev_name, LED_MAX_NAME_SIZE, fmt: "%s",
583 to_of_node(fwnode)->name);
584 } else
585 return -EINVAL;
586
587 if (n >= LED_MAX_NAME_SIZE)
588 return -E2BIG;
589
590 return 0;
591}
592EXPORT_SYMBOL_GPL(led_compose_name);
593
594const char *led_get_color_name(u8 color_id)
595{
596 if (color_id >= ARRAY_SIZE(led_colors))
597 return NULL;
598
599 return led_colors[color_id];
600}
601EXPORT_SYMBOL_GPL(led_get_color_name);
602
603enum led_default_state led_init_default_state_get(struct fwnode_handle *fwnode)
604{
605 const char *state = NULL;
606
607 if (!fwnode_property_read_string(fwnode, propname: "default-state", val: &state)) {
608 if (!strcmp(state, "keep"))
609 return LEDS_DEFSTATE_KEEP;
610 if (!strcmp(state, "on"))
611 return LEDS_DEFSTATE_ON;
612 }
613
614 return LEDS_DEFSTATE_OFF;
615}
616EXPORT_SYMBOL_GPL(led_init_default_state_get);
617