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28 /* This is obsolete/useless.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