summaryrefslogtreecommitdiff
path: root/drivers/leds/led-core.c
blob: f0c1c403f6784f9ced4e009875cb9911a9d1551a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
// SPDX-License-Identifier: GPL-2.0-only
/*
 * LED Class Core
 *
 * Copyright 2005-2006 Openedhand Ltd.
 *
 * Author: Richard Purdie <rpurdie@openedhand.com>
 */

#include <linux/kernel.h>
#include <linux/leds.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/property.h>
#include <linux/rwsem.h>
#include <linux/slab.h>
#include <uapi/linux/uleds.h>
#include "leds.h"

DECLARE_RWSEM(leds_list_lock);
EXPORT_SYMBOL_GPL(leds_list_lock);

LIST_HEAD(leds_list);
EXPORT_SYMBOL_GPL(leds_list);

const char * const led_colors[LED_COLOR_ID_MAX] = {
	[LED_COLOR_ID_WHITE] = "white",
	[LED_COLOR_ID_RED] = "red",
	[LED_COLOR_ID_GREEN] = "green",
	[LED_COLOR_ID_BLUE] = "blue",
	[LED_COLOR_ID_AMBER] = "amber",
	[LED_COLOR_ID_VIOLET] = "violet",
	[LED_COLOR_ID_YELLOW] = "yellow",
	[LED_COLOR_ID_IR] = "ir",
};
EXPORT_SYMBOL_GPL(led_colors);

static int __led_set_brightness(struct led_classdev *led_cdev,
				enum led_brightness value)
{
	if (!led_cdev->brightness_set)
		return -ENOTSUPP;

	led_cdev->brightness_set(led_cdev, value);

	return 0;
}

static int __led_set_brightness_blocking(struct led_classdev *led_cdev,
					 enum led_brightness value)
{
	if (!led_cdev->brightness_set_blocking)
		return -ENOTSUPP;

	return led_cdev->brightness_set_blocking(led_cdev, value);
}

static void led_timer_function(struct timer_list *t)
{
	struct led_classdev *led_cdev = from_timer(led_cdev, t, blink_timer);
	unsigned long brightness;
	unsigned long delay;

	if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) {
		led_set_brightness_nosleep(led_cdev, LED_OFF);
		clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
		return;
	}

	if (test_and_clear_bit(LED_BLINK_ONESHOT_STOP,
			       &led_cdev->work_flags)) {
		clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
		return;
	}

	brightness = led_get_brightness(led_cdev);
	if (!brightness) {
		/* Time to switch the LED on. */
		if (test_and_clear_bit(LED_BLINK_BRIGHTNESS_CHANGE,
					&led_cdev->work_flags))
			brightness = led_cdev->new_blink_brightness;
		else
			brightness = led_cdev->blink_brightness;
		delay = led_cdev->blink_delay_on;
	} else {
		/* Store the current brightness value to be able
		 * to restore it when the delay_off period is over.
		 */
		led_cdev->blink_brightness = brightness;
		brightness = LED_OFF;
		delay = led_cdev->blink_delay_off;
	}

	led_set_brightness_nosleep(led_cdev, brightness);

	/* Return in next iteration if led is in one-shot mode and we are in
	 * the final blink state so that the led is toggled each delay_on +
	 * delay_off milliseconds in worst case.
	 */
	if (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags)) {
		if (test_bit(LED_BLINK_INVERT, &led_cdev->work_flags)) {
			if (brightness)
				set_bit(LED_BLINK_ONESHOT_STOP,
					&led_cdev->work_flags);
		} else {
			if (!brightness)
				set_bit(LED_BLINK_ONESHOT_STOP,
					&led_cdev->work_flags);
		}
	}

	mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
}

static void set_brightness_delayed(struct work_struct *ws)
{
	struct led_classdev *led_cdev =
		container_of(ws, struct led_classdev, set_brightness_work);
	int ret = 0;

	if (test_and_clear_bit(LED_BLINK_DISABLE, &led_cdev->work_flags)) {
		led_cdev->delayed_set_value = LED_OFF;
		led_stop_software_blink(led_cdev);
	}

	ret = __led_set_brightness(led_cdev, led_cdev->delayed_set_value);
	if (ret == -ENOTSUPP)
		ret = __led_set_brightness_blocking(led_cdev,
					led_cdev->delayed_set_value);
	if (ret < 0 &&
	    /* LED HW might have been unplugged, therefore don't warn */
	    !(ret == -ENODEV && (led_cdev->flags & LED_UNREGISTERING) &&
	    (led_cdev->flags & LED_HW_PLUGGABLE)))
		dev_err(led_cdev->dev,
			"Setting an LED's brightness failed (%d)\n", ret);
}

static void led_set_software_blink(struct led_classdev *led_cdev,
				   unsigned long delay_on,
				   unsigned long delay_off)
{
	int current_brightness;

	current_brightness = led_get_brightness(led_cdev);
	if (current_brightness)
		led_cdev->blink_brightness = current_brightness;
	if (!led_cdev->blink_brightness)
		led_cdev->blink_brightness = led_cdev->max_brightness;

	led_cdev->blink_delay_on = delay_on;
	led_cdev->blink_delay_off = delay_off;

	/* never on - just set to off */
	if (!delay_on) {
		led_set_brightness_nosleep(led_cdev, LED_OFF);
		return;
	}

	/* never off - just set to brightness */
	if (!delay_off) {
		led_set_brightness_nosleep(led_cdev,
					   led_cdev->blink_brightness);
		return;
	}

	set_bit(LED_BLINK_SW, &led_cdev->work_flags);
	mod_timer(&led_cdev->blink_timer, jiffies + 1);
}


static void led_blink_setup(struct led_classdev *led_cdev,
		     unsigned long *delay_on,
		     unsigned long *delay_off)
{
	if (!test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) &&
	    led_cdev->blink_set &&
	    !led_cdev->blink_set(led_cdev, delay_on, delay_off))
		return;

	/* blink with 1 Hz as default if nothing specified */
	if (!*delay_on && !*delay_off)
		*delay_on = *delay_off = 500;

	led_set_software_blink(led_cdev, *delay_on, *delay_off);
}

void led_init_core(struct led_classdev *led_cdev)
{
	INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);

	timer_setup(&led_cdev->blink_timer, led_timer_function, 0);
}
EXPORT_SYMBOL_GPL(led_init_core);

void led_blink_set(struct led_classdev *led_cdev,
		   unsigned long *delay_on,
		   unsigned long *delay_off)
{
	del_timer_sync(&led_cdev->blink_timer);

	clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
	clear_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags);
	clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags);

	led_blink_setup(led_cdev, delay_on, delay_off);
}
EXPORT_SYMBOL_GPL(led_blink_set);

void led_blink_set_oneshot(struct led_classdev *led_cdev,
			   unsigned long *delay_on,
			   unsigned long *delay_off,
			   int invert)
{
	if (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) &&
	     timer_pending(&led_cdev->blink_timer))
		return;

	set_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags);
	clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags);

	if (invert)
		set_bit(LED_BLINK_INVERT, &led_cdev->work_flags);
	else
		clear_bit(LED_BLINK_INVERT, &led_cdev->work_flags);

	led_blink_setup(led_cdev, delay_on, delay_off);
}
EXPORT_SYMBOL_GPL(led_blink_set_oneshot);

void led_stop_software_blink(struct led_classdev *led_cdev)
{
	del_timer_sync(&led_cdev->blink_timer);
	led_cdev->blink_delay_on = 0;
	led_cdev->blink_delay_off = 0;
	clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
}
EXPORT_SYMBOL_GPL(led_stop_software_blink);

void led_set_brightness(struct led_classdev *led_cdev,
			enum led_brightness brightness)
{
	/*
	 * If software blink is active, delay brightness setting
	 * until the next timer tick.
	 */
	if (test_bit(LED_BLINK_SW, &led_cdev->work_flags)) {
		/*
		 * If we need to disable soft blinking delegate this to the
		 * work queue task to avoid problems in case we are called
		 * from hard irq context.
		 */
		if (brightness == LED_OFF) {
			set_bit(LED_BLINK_DISABLE, &led_cdev->work_flags);
			schedule_work(&led_cdev->set_brightness_work);
		} else {
			set_bit(LED_BLINK_BRIGHTNESS_CHANGE,
				&led_cdev->work_flags);
			led_cdev->new_blink_brightness = brightness;
		}
		return;
	}

	led_set_brightness_nosleep(led_cdev, brightness);
}
EXPORT_SYMBOL_GPL(led_set_brightness);

void led_set_brightness_nopm(struct led_classdev *led_cdev,
			      enum led_brightness value)
{
	/* Use brightness_set op if available, it is guaranteed not to sleep */
	if (!__led_set_brightness(led_cdev, value))
		return;

	/* If brightness setting can sleep, delegate it to a work queue task */
	led_cdev->delayed_set_value = value;
	schedule_work(&led_cdev->set_brightness_work);
}
EXPORT_SYMBOL_GPL(led_set_brightness_nopm);

void led_set_brightness_nosleep(struct led_classdev *led_cdev,
				enum led_brightness value)
{
	led_cdev->brightness = min(value, led_cdev->max_brightness);

	if (led_cdev->flags & LED_SUSPENDED)
		return;

	led_set_brightness_nopm(led_cdev, led_cdev->brightness);
}
EXPORT_SYMBOL_GPL(led_set_brightness_nosleep);

int led_set_brightness_sync(struct led_classdev *led_cdev,
			    enum led_brightness value)
{
	if (led_cdev->blink_delay_on || led_cdev->blink_delay_off)
		return -EBUSY;

	led_cdev->brightness = min(value, led_cdev->max_brightness);

	if (led_cdev->flags & LED_SUSPENDED)
		return 0;

	return __led_set_brightness_blocking(led_cdev, led_cdev->brightness);
}
EXPORT_SYMBOL_GPL(led_set_brightness_sync);

int led_update_brightness(struct led_classdev *led_cdev)
{
	int ret = 0;

	if (led_cdev->brightness_get) {
		ret = led_cdev->brightness_get(led_cdev);
		if (ret >= 0) {
			led_cdev->brightness = ret;
			return 0;
		}
	}

	return ret;
}
EXPORT_SYMBOL_GPL(led_update_brightness);

u32 *led_get_default_pattern(struct led_classdev *led_cdev, unsigned int *size)
{
	struct device_node *np = dev_of_node(led_cdev->dev);
	u32 *pattern;
	int count;

	if (!np)
		return NULL;

	count = of_property_count_u32_elems(np, "led-pattern");
	if (count < 0)
		return NULL;

	pattern = kcalloc(count, sizeof(*pattern), GFP_KERNEL);
	if (!pattern)
		return NULL;

	if (of_property_read_u32_array(np, "led-pattern", pattern, count)) {
		kfree(pattern);
		return NULL;
	}

	*size = count;

	return pattern;
}
EXPORT_SYMBOL_GPL(led_get_default_pattern);

/* Caller must ensure led_cdev->led_access held */
void led_sysfs_disable(struct led_classdev *led_cdev)
{
	lockdep_assert_held(&led_cdev->led_access);

	led_cdev->flags |= LED_SYSFS_DISABLE;
}
EXPORT_SYMBOL_GPL(led_sysfs_disable);

/* Caller must ensure led_cdev->led_access held */
void led_sysfs_enable(struct led_classdev *led_cdev)
{
	lockdep_assert_held(&led_cdev->led_access);

	led_cdev->flags &= ~LED_SYSFS_DISABLE;
}
EXPORT_SYMBOL_GPL(led_sysfs_enable);

static void led_parse_fwnode_props(struct device *dev,
				   struct fwnode_handle *fwnode,
				   struct led_properties *props)
{
	int ret;

	if (!fwnode)
		return;

	if (fwnode_property_present(fwnode, "label")) {
		ret = fwnode_property_read_string(fwnode, "label", &props->label);
		if (ret)
			dev_err(dev, "Error parsing 'label' property (%d)\n", ret);
		return;
	}

	if (fwnode_property_present(fwnode, "color")) {
		ret = fwnode_property_read_u32(fwnode, "color", &props->color);
		if (ret)
			dev_err(dev, "Error parsing 'color' property (%d)\n", ret);
		else if (props->color >= LED_COLOR_ID_MAX)
			dev_err(dev, "LED color identifier out of range\n");
		else
			props->color_present = true;
	}


	if (!fwnode_property_present(fwnode, "function"))
		return;

	ret = fwnode_property_read_string(fwnode, "function", &props->function);
	if (ret) {
		dev_err(dev,
			"Error parsing 'function' property (%d)\n",
			ret);
	}

	if (!fwnode_property_present(fwnode, "function-enumerator"))
		return;

	ret = fwnode_property_read_u32(fwnode, "function-enumerator",
				       &props->func_enum);
	if (ret) {
		dev_err(dev,
			"Error parsing 'function-enumerator' property (%d)\n",
			ret);
	} else {
		props->func_enum_present = true;
	}
}

int led_compose_name(struct device *dev, struct led_init_data *init_data,
		     char *led_classdev_name)
{
	struct led_properties props = {};
	struct fwnode_handle *fwnode = init_data->fwnode;
	const char *devicename = init_data->devicename;

	if (!led_classdev_name)
		return -EINVAL;

	led_parse_fwnode_props(dev, fwnode, &props);

	if (props.label) {
		/*
		 * If init_data.devicename is NULL, then it indicates that
		 * DT label should be used as-is for LED class device name.
		 * Otherwise the label is prepended with devicename to compose
		 * the final LED class device name.
		 */
		if (!devicename) {
			strscpy(led_classdev_name, props.label,
				LED_MAX_NAME_SIZE);
		} else {
			snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s",
				 devicename, props.label);
		}
	} else if (props.function || props.color_present) {
		char tmp_buf[LED_MAX_NAME_SIZE];

		if (props.func_enum_present) {
			snprintf(tmp_buf, LED_MAX_NAME_SIZE, "%s:%s-%d",
				 props.color_present ? led_colors[props.color] : "",
				 props.function ?: "", props.func_enum);
		} else {
			snprintf(tmp_buf, LED_MAX_NAME_SIZE, "%s:%s",
				 props.color_present ? led_colors[props.color] : "",
				 props.function ?: "");
		}
		if (init_data->devname_mandatory) {
			snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s",
				 devicename, tmp_buf);
		} else {
			strscpy(led_classdev_name, tmp_buf, LED_MAX_NAME_SIZE);

		}
	} else if (init_data->default_label) {
		if (!devicename) {
			dev_err(dev, "Legacy LED naming requires devicename segment");
			return -EINVAL;
		}
		snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s",
			 devicename, init_data->default_label);
	} else if (is_of_node(fwnode)) {
		strscpy(led_classdev_name, to_of_node(fwnode)->name,
			LED_MAX_NAME_SIZE);
	} else
		return -EINVAL;

	return 0;
}
EXPORT_SYMBOL_GPL(led_compose_name);