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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28 /* This is obsolete/useless.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 	enum led_brightness	 brightness;
67 	enum led_brightness	 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,
257 			enum led_brightness brightness);
258 
259 /**
260  * led_set_brightness_sync - set LED brightness synchronously
261  * @led_cdev: the LED to set
262  * @value: the brightness to set it to
263  *
264  * Set an LED's brightness immediately. This function will block
265  * the caller for the time required for accessing device registers,
266  * and it can sleep.
267  *
268  * Returns: 0 on success or negative error value on failure
269  */
270 int led_set_brightness_sync(struct led_classdev *led_cdev,
271 			    enum led_brightness value);
272 
273 /**
274  * led_update_brightness - update LED brightness
275  * @led_cdev: the LED to query
276  *
277  * Get an LED's current brightness and update led_cdev->brightness
278  * member with the obtained value.
279  *
280  * Returns: 0 on success or negative error value on failure
281  */
282 int led_update_brightness(struct led_classdev *led_cdev);
283 
284 /**
285  * led_get_default_pattern - return default pattern
286  *
287  * @led_cdev: the LED to get default pattern for
288  * @size:     pointer for storing the number of elements in returned array,
289  *            modified only if return != NULL
290  *
291  * Return:    Allocated array of integers with default pattern from device tree
292  *            or NULL.  Caller is responsible for kfree().
293  */
294 u32 *led_get_default_pattern(struct led_classdev *led_cdev, unsigned int *size);
295 
296 /**
297  * led_sysfs_disable - disable LED sysfs interface
298  * @led_cdev: the LED to set
299  *
300  * Disable the led_cdev's sysfs interface.
301  */
302 void led_sysfs_disable(struct led_classdev *led_cdev);
303 
304 /**
305  * led_sysfs_enable - enable LED sysfs interface
306  * @led_cdev: the LED to set
307  *
308  * Enable the led_cdev's sysfs interface.
309  */
310 void led_sysfs_enable(struct led_classdev *led_cdev);
311 
312 /**
313  * led_compose_name - compose LED class device name
314  * @dev: LED controller device object
315  * @init_data: the LED class device initialization data
316  * @led_classdev_name: composed LED class device name
317  *
318  * Create LED class device name basing on the provided init_data argument.
319  * The name can have <devicename:color:function> or <color:function>.
320  * form, depending on the init_data configuration.
321  *
322  * Returns: 0 on success or negative error value on failure
323  */
324 int led_compose_name(struct device *dev, struct led_init_data *init_data,
325 		     char *led_classdev_name);
326 
327 /**
328  * led_sysfs_is_disabled - check if LED sysfs interface is disabled
329  * @led_cdev: the LED to query
330  *
331  * Returns: true if the led_cdev's sysfs interface is disabled.
332  */
led_sysfs_is_disabled(struct led_classdev * led_cdev)333 static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
334 {
335 	return led_cdev->flags & LED_SYSFS_DISABLE;
336 }
337 
338 /*
339  * LED Triggers
340  */
341 /* Registration functions for simple triggers */
342 #define DEFINE_LED_TRIGGER(x)		static struct led_trigger *x;
343 #define DEFINE_LED_TRIGGER_GLOBAL(x)	struct led_trigger *x;
344 
345 #ifdef CONFIG_LEDS_TRIGGERS
346 
347 #define TRIG_NAME_MAX 50
348 
349 struct led_trigger {
350 	/* Trigger Properties */
351 	const char	 *name;
352 	int		(*activate)(struct led_classdev *led_cdev);
353 	void		(*deactivate)(struct led_classdev *led_cdev);
354 
355 	/* LED-private triggers have this set */
356 	struct led_hw_trigger_type *trigger_type;
357 
358 	/* LEDs under control by this trigger (for simple triggers) */
359 	rwlock_t	  leddev_list_lock;
360 	struct list_head  led_cdevs;
361 
362 	/* Link to next registered trigger */
363 	struct list_head  next_trig;
364 
365 	const struct attribute_group **groups;
366 };
367 
368 /*
369  * Currently the attributes in struct led_trigger::groups are added directly to
370  * the LED device. As this might change in the future, the following
371  * macros abstract getting the LED device and its trigger_data from the dev
372  * parameter passed to the attribute accessor functions.
373  */
374 #define led_trigger_get_led(dev)	((struct led_classdev *)dev_get_drvdata((dev)))
375 #define led_trigger_get_drvdata(dev)	(led_get_trigger_data(led_trigger_get_led(dev)))
376 
377 /* Registration functions for complex triggers */
378 int led_trigger_register(struct led_trigger *trigger);
379 void led_trigger_unregister(struct led_trigger *trigger);
380 int devm_led_trigger_register(struct device *dev,
381 				     struct led_trigger *trigger);
382 
383 void led_trigger_register_simple(const char *name,
384 				struct led_trigger **trigger);
385 void led_trigger_unregister_simple(struct led_trigger *trigger);
386 void led_trigger_event(struct led_trigger *trigger,  enum led_brightness event);
387 void led_trigger_blink(struct led_trigger *trigger, unsigned long *delay_on,
388 		       unsigned long *delay_off);
389 void led_trigger_blink_oneshot(struct led_trigger *trigger,
390 			       unsigned long *delay_on,
391 			       unsigned long *delay_off,
392 			       int invert);
393 void led_trigger_set_default(struct led_classdev *led_cdev);
394 int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger);
395 void led_trigger_remove(struct led_classdev *led_cdev);
396 
led_set_trigger_data(struct led_classdev * led_cdev,void * trigger_data)397 static inline void led_set_trigger_data(struct led_classdev *led_cdev,
398 					void *trigger_data)
399 {
400 	led_cdev->trigger_data = trigger_data;
401 }
402 
led_get_trigger_data(struct led_classdev * led_cdev)403 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
404 {
405 	return led_cdev->trigger_data;
406 }
407 
408 /**
409  * led_trigger_rename_static - rename a trigger
410  * @name: the new trigger name
411  * @trig: the LED trigger to rename
412  *
413  * Change a LED trigger name by copying the string passed in
414  * name into current trigger name, which MUST be large
415  * enough for the new string.
416  *
417  * Note that name must NOT point to the same string used
418  * during LED registration, as that could lead to races.
419  *
420  * This is meant to be used on triggers with statically
421  * allocated name.
422  */
423 void led_trigger_rename_static(const char *name, struct led_trigger *trig);
424 
425 #define module_led_trigger(__led_trigger) \
426 	module_driver(__led_trigger, led_trigger_register, \
427 		      led_trigger_unregister)
428 
429 #else
430 
431 /* Trigger has no members */
432 struct led_trigger {};
433 
434 /* Trigger inline empty functions */
led_trigger_register_simple(const char * name,struct led_trigger ** trigger)435 static inline void led_trigger_register_simple(const char *name,
436 					struct led_trigger **trigger) {}
led_trigger_unregister_simple(struct led_trigger * trigger)437 static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
led_trigger_event(struct led_trigger * trigger,enum led_brightness event)438 static inline void led_trigger_event(struct led_trigger *trigger,
439 				enum led_brightness event) {}
led_trigger_blink(struct led_trigger * trigger,unsigned long * delay_on,unsigned long * delay_off)440 static inline void led_trigger_blink(struct led_trigger *trigger,
441 				      unsigned long *delay_on,
442 				      unsigned long *delay_off) {}
led_trigger_blink_oneshot(struct led_trigger * trigger,unsigned long * delay_on,unsigned long * delay_off,int invert)443 static inline void led_trigger_blink_oneshot(struct led_trigger *trigger,
444 				      unsigned long *delay_on,
445 				      unsigned long *delay_off,
446 				      int invert) {}
led_trigger_set_default(struct led_classdev * led_cdev)447 static inline void led_trigger_set_default(struct led_classdev *led_cdev) {}
led_trigger_set(struct led_classdev * led_cdev,struct led_trigger * trigger)448 static inline int led_trigger_set(struct led_classdev *led_cdev,
449 				  struct led_trigger *trigger)
450 {
451 	return 0;
452 }
453 
led_trigger_remove(struct led_classdev * led_cdev)454 static inline void led_trigger_remove(struct led_classdev *led_cdev) {}
led_set_trigger_data(struct led_classdev * led_cdev)455 static inline void led_set_trigger_data(struct led_classdev *led_cdev) {}
led_get_trigger_data(struct led_classdev * led_cdev)456 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
457 {
458 	return NULL;
459 }
460 
461 #endif /* CONFIG_LEDS_TRIGGERS */
462 
463 /* Trigger specific functions */
464 #ifdef CONFIG_LEDS_TRIGGER_DISK
465 void ledtrig_disk_activity(bool write);
466 #else
ledtrig_disk_activity(bool write)467 static inline void ledtrig_disk_activity(bool write) {}
468 #endif
469 
470 #ifdef CONFIG_LEDS_TRIGGER_MTD
471 void ledtrig_mtd_activity(void);
472 #else
ledtrig_mtd_activity(void)473 static inline void ledtrig_mtd_activity(void) {}
474 #endif
475 
476 #if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
477 void ledtrig_flash_ctrl(bool on);
478 void ledtrig_torch_ctrl(bool on);
479 #else
ledtrig_flash_ctrl(bool on)480 static inline void ledtrig_flash_ctrl(bool on) {}
ledtrig_torch_ctrl(bool on)481 static inline void ledtrig_torch_ctrl(bool on) {}
482 #endif
483 
484 /*
485  * Generic LED platform data for describing LED names and default triggers.
486  */
487 struct led_info {
488 	const char	*name;
489 	const char	*default_trigger;
490 	int		flags;
491 };
492 
493 struct led_platform_data {
494 	int		num_leds;
495 	struct led_info	*leds;
496 };
497 
498 struct led_properties {
499 	u32		color;
500 	bool		color_present;
501 	const char	*function;
502 	u32		func_enum;
503 	bool		func_enum_present;
504 	const char	*label;
505 };
506 
507 struct gpio_desc;
508 typedef int (*gpio_blink_set_t)(struct gpio_desc *desc, int state,
509 				unsigned long *delay_on,
510 				unsigned long *delay_off);
511 
512 /* For the leds-gpio driver */
513 struct gpio_led {
514 	const char *name;
515 	const char *default_trigger;
516 	unsigned 	gpio;
517 	unsigned	active_low : 1;
518 	unsigned	retain_state_suspended : 1;
519 	unsigned	panic_indicator : 1;
520 	unsigned	default_state : 2;
521 	unsigned	retain_state_shutdown : 1;
522 	/* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
523 	struct gpio_desc *gpiod;
524 };
525 #define LEDS_GPIO_DEFSTATE_OFF		0
526 #define LEDS_GPIO_DEFSTATE_ON		1
527 #define LEDS_GPIO_DEFSTATE_KEEP		2
528 
529 struct gpio_led_platform_data {
530 	int 		num_leds;
531 	const struct gpio_led *leds;
532 
533 #define GPIO_LED_NO_BLINK_LOW	0	/* No blink GPIO state low */
534 #define GPIO_LED_NO_BLINK_HIGH	1	/* No blink GPIO state high */
535 #define GPIO_LED_BLINK		2	/* Please, blink */
536 	gpio_blink_set_t	gpio_blink_set;
537 };
538 
539 #ifdef CONFIG_NEW_LEDS
540 struct platform_device *gpio_led_register_device(
541 		int id, const struct gpio_led_platform_data *pdata);
542 #else
gpio_led_register_device(int id,const struct gpio_led_platform_data * pdata)543 static inline struct platform_device *gpio_led_register_device(
544 		int id, const struct gpio_led_platform_data *pdata)
545 {
546 	return 0;
547 }
548 #endif
549 
550 enum cpu_led_event {
551 	CPU_LED_IDLE_START,	/* CPU enters idle */
552 	CPU_LED_IDLE_END,	/* CPU idle ends */
553 	CPU_LED_START,		/* Machine starts, especially resume */
554 	CPU_LED_STOP,		/* Machine stops, especially suspend */
555 	CPU_LED_HALTED,		/* Machine shutdown */
556 };
557 #ifdef CONFIG_LEDS_TRIGGER_CPU
558 void ledtrig_cpu(enum cpu_led_event evt);
559 #else
ledtrig_cpu(enum cpu_led_event evt)560 static inline void ledtrig_cpu(enum cpu_led_event evt)
561 {
562 	return;
563 }
564 #endif
565 
566 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
567 void led_classdev_notify_brightness_hw_changed(
568 	struct led_classdev *led_cdev, enum led_brightness brightness);
569 #else
led_classdev_notify_brightness_hw_changed(struct led_classdev * led_cdev,enum led_brightness brightness)570 static inline void led_classdev_notify_brightness_hw_changed(
571 	struct led_classdev *led_cdev, enum led_brightness brightness) { }
572 #endif
573 
574 /**
575  * struct led_pattern - pattern interval settings
576  * @delta_t: pattern interval delay, in milliseconds
577  * @brightness: pattern interval brightness
578  */
579 struct led_pattern {
580 	u32 delta_t;
581 	int brightness;
582 };
583 
584 enum led_audio {
585 	LED_AUDIO_MUTE,		/* master mute LED */
586 	LED_AUDIO_MICMUTE,	/* mic mute LED */
587 	NUM_AUDIO_LEDS
588 };
589 
590 #if IS_ENABLED(CONFIG_LEDS_TRIGGER_AUDIO)
591 enum led_brightness ledtrig_audio_get(enum led_audio type);
592 void ledtrig_audio_set(enum led_audio type, enum led_brightness state);
593 #else
ledtrig_audio_get(enum led_audio type)594 static inline enum led_brightness ledtrig_audio_get(enum led_audio type)
595 {
596 	return LED_OFF;
597 }
ledtrig_audio_set(enum led_audio type,enum led_brightness state)598 static inline void ledtrig_audio_set(enum led_audio type,
599 				     enum led_brightness state)
600 {
601 }
602 #endif
603 
604 #endif		/* __LINUX_LEDS_H_INCLUDED */
605