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28 /* This is obsolete/useless.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 	spinlock_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