1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Driver model for leds and led triggers
4 *
5 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
6 * Copyright (C) 2005 Richard Purdie <rpurdie@openedhand.com>
7 */
8 #ifndef __LINUX_LEDS_H_INCLUDED
9 #define __LINUX_LEDS_H_INCLUDED
10
11 #include <dt-bindings/leds/common.h>
12 #include <linux/device.h>
13 #include <linux/kernfs.h>
14 #include <linux/list.h>
15 #include <linux/mutex.h>
16 #include <linux/rwsem.h>
17 #include <linux/spinlock.h>
18 #include <linux/timer.h>
19 #include <linux/workqueue.h>
20
21 struct device;
22 struct led_pattern;
23 struct device_node;
24 /*
25 * LED Core
26 */
27
28 /* This is obsolete/useless. We now support variable maximum brightness. */
29 enum led_brightness {
30 LED_OFF = 0,
31 LED_ON = 1,
32 LED_HALF = 127,
33 LED_FULL = 255,
34 };
35
36 enum led_default_state {
37 LEDS_DEFSTATE_OFF = 0,
38 LEDS_DEFSTATE_ON = 1,
39 LEDS_DEFSTATE_KEEP = 2,
40 };
41
42 struct led_init_data {
43 /* device fwnode handle */
44 struct fwnode_handle *fwnode;
45 /*
46 * default <color:function> tuple, for backward compatibility
47 * with in-driver hard-coded LED names used as a fallback when
48 * DT "label" property is absent; it should be set to NULL
49 * in new LED class drivers.
50 */
51 const char *default_label;
52 /*
53 * string to be used for devicename section of LED class device
54 * either for label based LED name composition path or for fwnode
55 * based when devname_mandatory is true
56 */
57 const char *devicename;
58 /*
59 * indicates if LED name should always comprise devicename section;
60 * only LEDs exposed by drivers of hot-pluggable devices should
61 * set it to true
62 */
63 bool devname_mandatory;
64 };
65
66 struct led_hw_trigger_type {
67 int dummy;
68 };
69
70 struct led_classdev {
71 const char *name;
72 unsigned int brightness;
73 unsigned int max_brightness;
74 int flags;
75
76 /* Lower 16 bits reflect status */
77 #define LED_SUSPENDED BIT(0)
78 #define LED_UNREGISTERING BIT(1)
79 /* Upper 16 bits reflect control information */
80 #define LED_CORE_SUSPENDRESUME BIT(16)
81 #define LED_SYSFS_DISABLE BIT(17)
82 #define LED_DEV_CAP_FLASH BIT(18)
83 #define LED_HW_PLUGGABLE BIT(19)
84 #define LED_PANIC_INDICATOR BIT(20)
85 #define LED_BRIGHT_HW_CHANGED BIT(21)
86 #define LED_RETAIN_AT_SHUTDOWN BIT(22)
87 #define LED_INIT_DEFAULT_TRIGGER BIT(23)
88
89 /* set_brightness_work / blink_timer flags, atomic, private. */
90 unsigned long work_flags;
91
92 #define LED_BLINK_SW 0
93 #define LED_BLINK_ONESHOT 1
94 #define LED_BLINK_ONESHOT_STOP 2
95 #define LED_BLINK_INVERT 3
96 #define LED_BLINK_BRIGHTNESS_CHANGE 4
97 #define LED_BLINK_DISABLE 5
98
99 /* Set LED brightness level
100 * Must not sleep. Use brightness_set_blocking for drivers
101 * that can sleep while setting brightness.
102 */
103 void (*brightness_set)(struct led_classdev *led_cdev,
104 enum led_brightness brightness);
105 /*
106 * Set LED brightness level immediately - it can block the caller for
107 * the time required for accessing a LED device register.
108 */
109 int (*brightness_set_blocking)(struct led_classdev *led_cdev,
110 enum led_brightness brightness);
111 /* Get LED brightness level */
112 enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
113
114 /*
115 * Activate hardware accelerated blink, delays are in milliseconds
116 * and if both are zero then a sensible default should be chosen.
117 * The call should adjust the timings in that case and if it can't
118 * match the values specified exactly.
119 * Deactivate blinking again when the brightness is set to LED_OFF
120 * via the brightness_set() callback.
121 */
122 int (*blink_set)(struct led_classdev *led_cdev,
123 unsigned long *delay_on,
124 unsigned long *delay_off);
125
126 int (*pattern_set)(struct led_classdev *led_cdev,
127 struct led_pattern *pattern, u32 len, int repeat);
128 int (*pattern_clear)(struct led_classdev *led_cdev);
129
130 struct device *dev;
131 const struct attribute_group **groups;
132
133 struct list_head node; /* LED Device list */
134 const char *default_trigger; /* Trigger to use */
135
136 unsigned long blink_delay_on, blink_delay_off;
137 struct timer_list blink_timer;
138 int blink_brightness;
139 int new_blink_brightness;
140 void (*flash_resume)(struct led_classdev *led_cdev);
141
142 struct work_struct set_brightness_work;
143 int delayed_set_value;
144
145 #ifdef CONFIG_LEDS_TRIGGERS
146 /* Protects the trigger data below */
147 struct rw_semaphore trigger_lock;
148
149 struct led_trigger *trigger;
150 struct list_head trig_list;
151 void *trigger_data;
152 /* true if activated - deactivate routine uses it to do cleanup */
153 bool activated;
154
155 /* LEDs that have private triggers have this set */
156 struct led_hw_trigger_type *trigger_type;
157 #endif
158
159 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
160 int brightness_hw_changed;
161 struct kernfs_node *brightness_hw_changed_kn;
162 #endif
163
164 /* Ensures consistent access to the LED Flash Class device */
165 struct mutex led_access;
166 };
167
168 /**
169 * led_classdev_register_ext - register a new object of LED class with
170 * init data
171 * @parent: LED controller device this LED is driven by
172 * @led_cdev: the led_classdev structure for this device
173 * @init_data: the LED class device initialization data
174 *
175 * Register a new object of LED class, with name derived from init_data.
176 *
177 * Returns: 0 on success or negative error value on failure
178 */
179 int led_classdev_register_ext(struct device *parent,
180 struct led_classdev *led_cdev,
181 struct led_init_data *init_data);
182
183 /**
184 * led_classdev_register - register a new object of LED class
185 * @parent: LED controller device this LED is driven by
186 * @led_cdev: the led_classdev structure for this device
187 *
188 * Register a new object of LED class, with name derived from the name property
189 * of passed led_cdev argument.
190 *
191 * Returns: 0 on success or negative error value on failure
192 */
led_classdev_register(struct device * parent,struct led_classdev * led_cdev)193 static inline int led_classdev_register(struct device *parent,
194 struct led_classdev *led_cdev)
195 {
196 return led_classdev_register_ext(parent, led_cdev, NULL);
197 }
198
199 int devm_led_classdev_register_ext(struct device *parent,
200 struct led_classdev *led_cdev,
201 struct led_init_data *init_data);
202
devm_led_classdev_register(struct device * parent,struct led_classdev * led_cdev)203 static inline int devm_led_classdev_register(struct device *parent,
204 struct led_classdev *led_cdev)
205 {
206 return devm_led_classdev_register_ext(parent, led_cdev, NULL);
207 }
208 void led_classdev_unregister(struct led_classdev *led_cdev);
209 void devm_led_classdev_unregister(struct device *parent,
210 struct led_classdev *led_cdev);
211 void led_classdev_suspend(struct led_classdev *led_cdev);
212 void led_classdev_resume(struct led_classdev *led_cdev);
213
214 extern struct led_classdev *of_led_get(struct device_node *np, int index);
215 extern void led_put(struct led_classdev *led_cdev);
216 struct led_classdev *__must_check devm_of_led_get(struct device *dev,
217 int index);
218
219 /**
220 * led_blink_set - set blinking with software fallback
221 * @led_cdev: the LED to start blinking
222 * @delay_on: the time it should be on (in ms)
223 * @delay_off: the time it should ble off (in ms)
224 *
225 * This function makes the LED blink, attempting to use the
226 * hardware acceleration if possible, but falling back to
227 * software blinking if there is no hardware blinking or if
228 * the LED refuses the passed values.
229 *
230 * Note that if software blinking is active, simply calling
231 * led_cdev->brightness_set() will not stop the blinking,
232 * use led_classdev_brightness_set() instead.
233 */
234 void led_blink_set(struct led_classdev *led_cdev, unsigned long *delay_on,
235 unsigned long *delay_off);
236 /**
237 * led_blink_set_oneshot - do a oneshot software blink
238 * @led_cdev: the LED to start blinking
239 * @delay_on: the time it should be on (in ms)
240 * @delay_off: the time it should ble off (in ms)
241 * @invert: blink off, then on, leaving the led on
242 *
243 * This function makes the LED blink one time for delay_on +
244 * delay_off time, ignoring the request if another one-shot
245 * blink is already in progress.
246 *
247 * If invert is set, led blinks for delay_off first, then for
248 * delay_on and leave the led on after the on-off cycle.
249 */
250 void led_blink_set_oneshot(struct led_classdev *led_cdev,
251 unsigned long *delay_on, unsigned long *delay_off,
252 int invert);
253 /**
254 * led_set_brightness - set LED brightness
255 * @led_cdev: the LED to set
256 * @brightness: the brightness to set it to
257 *
258 * Set an LED's brightness, and, if necessary, cancel the
259 * software blink timer that implements blinking when the
260 * hardware doesn't. This function is guaranteed not to sleep.
261 */
262 void led_set_brightness(struct led_classdev *led_cdev, unsigned int brightness);
263
264 /**
265 * led_set_brightness_sync - set LED brightness synchronously
266 * @led_cdev: the LED to set
267 * @value: the brightness to set it to
268 *
269 * Set an LED's brightness immediately. This function will block
270 * the caller for the time required for accessing device registers,
271 * and it can sleep.
272 *
273 * Returns: 0 on success or negative error value on failure
274 */
275 int led_set_brightness_sync(struct led_classdev *led_cdev, unsigned int value);
276
277 /**
278 * led_update_brightness - update LED brightness
279 * @led_cdev: the LED to query
280 *
281 * Get an LED's current brightness and update led_cdev->brightness
282 * member with the obtained value.
283 *
284 * Returns: 0 on success or negative error value on failure
285 */
286 int led_update_brightness(struct led_classdev *led_cdev);
287
288 /**
289 * led_get_default_pattern - return default pattern
290 *
291 * @led_cdev: the LED to get default pattern for
292 * @size: pointer for storing the number of elements in returned array,
293 * modified only if return != NULL
294 *
295 * Return: Allocated array of integers with default pattern from device tree
296 * or NULL. Caller is responsible for kfree().
297 */
298 u32 *led_get_default_pattern(struct led_classdev *led_cdev, unsigned int *size);
299
300 /**
301 * led_sysfs_disable - disable LED sysfs interface
302 * @led_cdev: the LED to set
303 *
304 * Disable the led_cdev's sysfs interface.
305 */
306 void led_sysfs_disable(struct led_classdev *led_cdev);
307
308 /**
309 * led_sysfs_enable - enable LED sysfs interface
310 * @led_cdev: the LED to set
311 *
312 * Enable the led_cdev's sysfs interface.
313 */
314 void led_sysfs_enable(struct led_classdev *led_cdev);
315
316 /**
317 * led_compose_name - compose LED class device name
318 * @dev: LED controller device object
319 * @init_data: the LED class device initialization data
320 * @led_classdev_name: composed LED class device name
321 *
322 * Create LED class device name basing on the provided init_data argument.
323 * The name can have <devicename:color:function> or <color:function>.
324 * form, depending on the init_data configuration.
325 *
326 * Returns: 0 on success or negative error value on failure
327 */
328 int led_compose_name(struct device *dev, struct led_init_data *init_data,
329 char *led_classdev_name);
330
331 /**
332 * led_sysfs_is_disabled - check if LED sysfs interface is disabled
333 * @led_cdev: the LED to query
334 *
335 * Returns: true if the led_cdev's sysfs interface is disabled.
336 */
led_sysfs_is_disabled(struct led_classdev * led_cdev)337 static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
338 {
339 return led_cdev->flags & LED_SYSFS_DISABLE;
340 }
341
342 /*
343 * LED Triggers
344 */
345 /* Registration functions for simple triggers */
346 #define DEFINE_LED_TRIGGER(x) static struct led_trigger *x;
347 #define DEFINE_LED_TRIGGER_GLOBAL(x) struct led_trigger *x;
348
349 #ifdef CONFIG_LEDS_TRIGGERS
350
351 #define TRIG_NAME_MAX 50
352
353 struct led_trigger {
354 /* Trigger Properties */
355 const char *name;
356 int (*activate)(struct led_classdev *led_cdev);
357 void (*deactivate)(struct led_classdev *led_cdev);
358
359 /* LED-private triggers have this set */
360 struct led_hw_trigger_type *trigger_type;
361
362 /* LEDs under control by this trigger (for simple triggers) */
363 rwlock_t leddev_list_lock;
364 struct list_head led_cdevs;
365
366 /* Link to next registered trigger */
367 struct list_head next_trig;
368
369 const struct attribute_group **groups;
370 };
371
372 /*
373 * Currently the attributes in struct led_trigger::groups are added directly to
374 * the LED device. As this might change in the future, the following
375 * macros abstract getting the LED device and its trigger_data from the dev
376 * parameter passed to the attribute accessor functions.
377 */
378 #define led_trigger_get_led(dev) ((struct led_classdev *)dev_get_drvdata((dev)))
379 #define led_trigger_get_drvdata(dev) (led_get_trigger_data(led_trigger_get_led(dev)))
380
381 /* Registration functions for complex triggers */
382 int led_trigger_register(struct led_trigger *trigger);
383 void led_trigger_unregister(struct led_trigger *trigger);
384 int devm_led_trigger_register(struct device *dev,
385 struct led_trigger *trigger);
386
387 void led_trigger_register_simple(const char *name,
388 struct led_trigger **trigger);
389 void led_trigger_unregister_simple(struct led_trigger *trigger);
390 void led_trigger_event(struct led_trigger *trigger, enum led_brightness event);
391 void led_trigger_blink(struct led_trigger *trigger, unsigned long *delay_on,
392 unsigned long *delay_off);
393 void led_trigger_blink_oneshot(struct led_trigger *trigger,
394 unsigned long *delay_on,
395 unsigned long *delay_off,
396 int invert);
397 void led_trigger_set_default(struct led_classdev *led_cdev);
398 int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger);
399 void led_trigger_remove(struct led_classdev *led_cdev);
400
led_set_trigger_data(struct led_classdev * led_cdev,void * trigger_data)401 static inline void led_set_trigger_data(struct led_classdev *led_cdev,
402 void *trigger_data)
403 {
404 led_cdev->trigger_data = trigger_data;
405 }
406
led_get_trigger_data(struct led_classdev * led_cdev)407 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
408 {
409 return led_cdev->trigger_data;
410 }
411
412 /**
413 * led_trigger_rename_static - rename a trigger
414 * @name: the new trigger name
415 * @trig: the LED trigger to rename
416 *
417 * Change a LED trigger name by copying the string passed in
418 * name into current trigger name, which MUST be large
419 * enough for the new string.
420 *
421 * Note that name must NOT point to the same string used
422 * during LED registration, as that could lead to races.
423 *
424 * This is meant to be used on triggers with statically
425 * allocated name.
426 */
427 void led_trigger_rename_static(const char *name, struct led_trigger *trig);
428
429 #define module_led_trigger(__led_trigger) \
430 module_driver(__led_trigger, led_trigger_register, \
431 led_trigger_unregister)
432
433 #else
434
435 /* Trigger has no members */
436 struct led_trigger {};
437
438 /* Trigger inline empty functions */
led_trigger_register_simple(const char * name,struct led_trigger ** trigger)439 static inline void led_trigger_register_simple(const char *name,
440 struct led_trigger **trigger) {}
led_trigger_unregister_simple(struct led_trigger * trigger)441 static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
led_trigger_event(struct led_trigger * trigger,enum led_brightness event)442 static inline void led_trigger_event(struct led_trigger *trigger,
443 enum led_brightness event) {}
led_trigger_blink(struct led_trigger * trigger,unsigned long * delay_on,unsigned long * delay_off)444 static inline void led_trigger_blink(struct led_trigger *trigger,
445 unsigned long *delay_on,
446 unsigned long *delay_off) {}
led_trigger_blink_oneshot(struct led_trigger * trigger,unsigned long * delay_on,unsigned long * delay_off,int invert)447 static inline void led_trigger_blink_oneshot(struct led_trigger *trigger,
448 unsigned long *delay_on,
449 unsigned long *delay_off,
450 int invert) {}
led_trigger_set_default(struct led_classdev * led_cdev)451 static inline void led_trigger_set_default(struct led_classdev *led_cdev) {}
led_trigger_set(struct led_classdev * led_cdev,struct led_trigger * trigger)452 static inline int led_trigger_set(struct led_classdev *led_cdev,
453 struct led_trigger *trigger)
454 {
455 return 0;
456 }
457
led_trigger_remove(struct led_classdev * led_cdev)458 static inline void led_trigger_remove(struct led_classdev *led_cdev) {}
led_set_trigger_data(struct led_classdev * led_cdev)459 static inline void led_set_trigger_data(struct led_classdev *led_cdev) {}
led_get_trigger_data(struct led_classdev * led_cdev)460 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
461 {
462 return NULL;
463 }
464
465 #endif /* CONFIG_LEDS_TRIGGERS */
466
467 /* Trigger specific functions */
468 #ifdef CONFIG_LEDS_TRIGGER_DISK
469 void ledtrig_disk_activity(bool write);
470 #else
ledtrig_disk_activity(bool write)471 static inline void ledtrig_disk_activity(bool write) {}
472 #endif
473
474 #ifdef CONFIG_LEDS_TRIGGER_MTD
475 void ledtrig_mtd_activity(void);
476 #else
ledtrig_mtd_activity(void)477 static inline void ledtrig_mtd_activity(void) {}
478 #endif
479
480 #if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
481 void ledtrig_flash_ctrl(bool on);
482 void ledtrig_torch_ctrl(bool on);
483 #else
ledtrig_flash_ctrl(bool on)484 static inline void ledtrig_flash_ctrl(bool on) {}
ledtrig_torch_ctrl(bool on)485 static inline void ledtrig_torch_ctrl(bool on) {}
486 #endif
487
488 /*
489 * Generic LED platform data for describing LED names and default triggers.
490 */
491 struct led_info {
492 const char *name;
493 const char *default_trigger;
494 int flags;
495 };
496
497 struct led_platform_data {
498 int num_leds;
499 struct led_info *leds;
500 };
501
502 struct led_properties {
503 u32 color;
504 bool color_present;
505 const char *function;
506 u32 func_enum;
507 bool func_enum_present;
508 const char *label;
509 };
510
511 struct gpio_desc;
512 typedef int (*gpio_blink_set_t)(struct gpio_desc *desc, int state,
513 unsigned long *delay_on,
514 unsigned long *delay_off);
515
516 /* For the leds-gpio driver */
517 struct gpio_led {
518 const char *name;
519 const char *default_trigger;
520 unsigned gpio;
521 unsigned active_low : 1;
522 unsigned retain_state_suspended : 1;
523 unsigned panic_indicator : 1;
524 unsigned default_state : 2;
525 unsigned retain_state_shutdown : 1;
526 /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
527 struct gpio_desc *gpiod;
528 };
529 #define LEDS_GPIO_DEFSTATE_OFF LEDS_DEFSTATE_OFF
530 #define LEDS_GPIO_DEFSTATE_ON LEDS_DEFSTATE_ON
531 #define LEDS_GPIO_DEFSTATE_KEEP LEDS_DEFSTATE_KEEP
532
533 struct gpio_led_platform_data {
534 int num_leds;
535 const struct gpio_led *leds;
536
537 #define GPIO_LED_NO_BLINK_LOW 0 /* No blink GPIO state low */
538 #define GPIO_LED_NO_BLINK_HIGH 1 /* No blink GPIO state high */
539 #define GPIO_LED_BLINK 2 /* Please, blink */
540 gpio_blink_set_t gpio_blink_set;
541 };
542
543 #ifdef CONFIG_NEW_LEDS
544 struct platform_device *gpio_led_register_device(
545 int id, const struct gpio_led_platform_data *pdata);
546 #else
gpio_led_register_device(int id,const struct gpio_led_platform_data * pdata)547 static inline struct platform_device *gpio_led_register_device(
548 int id, const struct gpio_led_platform_data *pdata)
549 {
550 return 0;
551 }
552 #endif
553
554 enum cpu_led_event {
555 CPU_LED_IDLE_START, /* CPU enters idle */
556 CPU_LED_IDLE_END, /* CPU idle ends */
557 CPU_LED_START, /* Machine starts, especially resume */
558 CPU_LED_STOP, /* Machine stops, especially suspend */
559 CPU_LED_HALTED, /* Machine shutdown */
560 };
561 #ifdef CONFIG_LEDS_TRIGGER_CPU
562 void ledtrig_cpu(enum cpu_led_event evt);
563 #else
ledtrig_cpu(enum cpu_led_event evt)564 static inline void ledtrig_cpu(enum cpu_led_event evt)
565 {
566 return;
567 }
568 #endif
569
570 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
571 void led_classdev_notify_brightness_hw_changed(
572 struct led_classdev *led_cdev, unsigned int brightness);
573 #else
led_classdev_notify_brightness_hw_changed(struct led_classdev * led_cdev,enum led_brightness brightness)574 static inline void led_classdev_notify_brightness_hw_changed(
575 struct led_classdev *led_cdev, enum led_brightness brightness) { }
576 #endif
577
578 /**
579 * struct led_pattern - pattern interval settings
580 * @delta_t: pattern interval delay, in milliseconds
581 * @brightness: pattern interval brightness
582 */
583 struct led_pattern {
584 u32 delta_t;
585 int brightness;
586 };
587
588 enum led_audio {
589 LED_AUDIO_MUTE, /* master mute LED */
590 LED_AUDIO_MICMUTE, /* mic mute LED */
591 NUM_AUDIO_LEDS
592 };
593
594 #if IS_ENABLED(CONFIG_LEDS_TRIGGER_AUDIO)
595 enum led_brightness ledtrig_audio_get(enum led_audio type);
596 void ledtrig_audio_set(enum led_audio type, enum led_brightness state);
597 #else
ledtrig_audio_get(enum led_audio type)598 static inline enum led_brightness ledtrig_audio_get(enum led_audio type)
599 {
600 return LED_OFF;
601 }
ledtrig_audio_set(enum led_audio type,enum led_brightness state)602 static inline void ledtrig_audio_set(enum led_audio type,
603 enum led_brightness state)
604 {
605 }
606 #endif
607
608 #endif /* __LINUX_LEDS_H_INCLUDED */
609
