xref: /linux-6.15/include/linux/leds.h (revision 8fdff1dc)
1 /*
2  * Driver model for leds and led triggers
3  *
4  * Copyright (C) 2005 John Lenz <[email protected]>
5  * Copyright (C) 2005 Richard Purdie <[email protected]>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  */
12 #ifndef __LINUX_LEDS_H_INCLUDED
13 #define __LINUX_LEDS_H_INCLUDED
14 
15 #include <linux/list.h>
16 #include <linux/spinlock.h>
17 #include <linux/rwsem.h>
18 #include <linux/timer.h>
19 #include <linux/workqueue.h>
20 
21 struct device;
22 /*
23  * LED Core
24  */
25 
26 enum led_brightness {
27 	LED_OFF		= 0,
28 	LED_HALF	= 127,
29 	LED_FULL	= 255,
30 };
31 
32 struct led_classdev {
33 	const char		*name;
34 	int			 brightness;
35 	int			 max_brightness;
36 	int			 flags;
37 
38 	/* Lower 16 bits reflect status */
39 #define LED_SUSPENDED		(1 << 0)
40 	/* Upper 16 bits reflect control information */
41 #define LED_CORE_SUSPENDRESUME	(1 << 16)
42 #define LED_BLINK_ONESHOT	(1 << 17)
43 #define LED_BLINK_ONESHOT_STOP	(1 << 18)
44 #define LED_BLINK_INVERT	(1 << 19)
45 
46 	/* Set LED brightness level */
47 	/* Must not sleep, use a workqueue if needed */
48 	void		(*brightness_set)(struct led_classdev *led_cdev,
49 					  enum led_brightness brightness);
50 	/* Get LED brightness level */
51 	enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
52 
53 	/*
54 	 * Activate hardware accelerated blink, delays are in milliseconds
55 	 * and if both are zero then a sensible default should be chosen.
56 	 * The call should adjust the timings in that case and if it can't
57 	 * match the values specified exactly.
58 	 * Deactivate blinking again when the brightness is set to a fixed
59 	 * value via the brightness_set() callback.
60 	 */
61 	int		(*blink_set)(struct led_classdev *led_cdev,
62 				     unsigned long *delay_on,
63 				     unsigned long *delay_off);
64 
65 	struct device		*dev;
66 	struct list_head	 node;			/* LED Device list */
67 	const char		*default_trigger;	/* Trigger to use */
68 
69 	unsigned long		 blink_delay_on, blink_delay_off;
70 	struct timer_list	 blink_timer;
71 	int			 blink_brightness;
72 
73 	struct work_struct	set_brightness_work;
74 	int			delayed_set_value;
75 
76 #ifdef CONFIG_LEDS_TRIGGERS
77 	/* Protects the trigger data below */
78 	struct rw_semaphore	 trigger_lock;
79 
80 	struct led_trigger	*trigger;
81 	struct list_head	 trig_list;
82 	void			*trigger_data;
83 	/* true if activated - deactivate routine uses it to do cleanup */
84 	bool			activated;
85 #endif
86 };
87 
88 extern int led_classdev_register(struct device *parent,
89 				 struct led_classdev *led_cdev);
90 extern void led_classdev_unregister(struct led_classdev *led_cdev);
91 extern void led_classdev_suspend(struct led_classdev *led_cdev);
92 extern void led_classdev_resume(struct led_classdev *led_cdev);
93 
94 /**
95  * led_blink_set - set blinking with software fallback
96  * @led_cdev: the LED to start blinking
97  * @delay_on: the time it should be on (in ms)
98  * @delay_off: the time it should ble off (in ms)
99  *
100  * This function makes the LED blink, attempting to use the
101  * hardware acceleration if possible, but falling back to
102  * software blinking if there is no hardware blinking or if
103  * the LED refuses the passed values.
104  *
105  * Note that if software blinking is active, simply calling
106  * led_cdev->brightness_set() will not stop the blinking,
107  * use led_classdev_brightness_set() instead.
108  */
109 extern void led_blink_set(struct led_classdev *led_cdev,
110 			  unsigned long *delay_on,
111 			  unsigned long *delay_off);
112 /**
113  * led_blink_set_oneshot - do a oneshot software blink
114  * @led_cdev: the LED to start blinking
115  * @delay_on: the time it should be on (in ms)
116  * @delay_off: the time it should ble off (in ms)
117  * @invert: blink off, then on, leaving the led on
118  *
119  * This function makes the LED blink one time for delay_on +
120  * delay_off time, ignoring the request if another one-shot
121  * blink is already in progress.
122  *
123  * If invert is set, led blinks for delay_off first, then for
124  * delay_on and leave the led on after the on-off cycle.
125  */
126 extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
127 				  unsigned long *delay_on,
128 				  unsigned long *delay_off,
129 				  int invert);
130 /**
131  * led_set_brightness - set LED brightness
132  * @led_cdev: the LED to set
133  * @brightness: the brightness to set it to
134  *
135  * Set an LED's brightness, and, if necessary, cancel the
136  * software blink timer that implements blinking when the
137  * hardware doesn't.
138  */
139 extern void led_set_brightness(struct led_classdev *led_cdev,
140 			       enum led_brightness brightness);
141 
142 /*
143  * LED Triggers
144  */
145 #ifdef CONFIG_LEDS_TRIGGERS
146 
147 #define TRIG_NAME_MAX 50
148 
149 struct led_trigger {
150 	/* Trigger Properties */
151 	const char	 *name;
152 	void		(*activate)(struct led_classdev *led_cdev);
153 	void		(*deactivate)(struct led_classdev *led_cdev);
154 
155 	/* LEDs under control by this trigger (for simple triggers) */
156 	rwlock_t	  leddev_list_lock;
157 	struct list_head  led_cdevs;
158 
159 	/* Link to next registered trigger */
160 	struct list_head  next_trig;
161 };
162 
163 /* Registration functions for complex triggers */
164 extern int led_trigger_register(struct led_trigger *trigger);
165 extern void led_trigger_unregister(struct led_trigger *trigger);
166 
167 /* Registration functions for simple triggers */
168 #define DEFINE_LED_TRIGGER(x)		static struct led_trigger *x;
169 #define DEFINE_LED_TRIGGER_GLOBAL(x)	struct led_trigger *x;
170 extern void led_trigger_register_simple(const char *name,
171 				struct led_trigger **trigger);
172 extern void led_trigger_unregister_simple(struct led_trigger *trigger);
173 extern void led_trigger_event(struct led_trigger *trigger,
174 				enum led_brightness event);
175 extern void led_trigger_blink(struct led_trigger *trigger,
176 			      unsigned long *delay_on,
177 			      unsigned long *delay_off);
178 extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
179 				      unsigned long *delay_on,
180 				      unsigned long *delay_off,
181 				      int invert);
182 /**
183  * led_trigger_rename_static - rename a trigger
184  * @name: the new trigger name
185  * @trig: the LED trigger to rename
186  *
187  * Change a LED trigger name by copying the string passed in
188  * name into current trigger name, which MUST be large
189  * enough for the new string.
190  *
191  * Note that name must NOT point to the same string used
192  * during LED registration, as that could lead to races.
193  *
194  * This is meant to be used on triggers with statically
195  * allocated name.
196  */
197 extern void led_trigger_rename_static(const char *name,
198 				      struct led_trigger *trig);
199 
200 #else
201 
202 /* Triggers aren't active - null macros */
203 #define DEFINE_LED_TRIGGER(x)
204 #define DEFINE_LED_TRIGGER_GLOBAL(x)
205 #define led_trigger_register_simple(x, y) do {} while(0)
206 #define led_trigger_unregister_simple(x) do {} while(0)
207 #define led_trigger_event(x, y) do {} while(0)
208 
209 #endif
210 
211 /* Trigger specific functions */
212 #ifdef CONFIG_LEDS_TRIGGER_IDE_DISK
213 extern void ledtrig_ide_activity(void);
214 #else
215 #define ledtrig_ide_activity() do {} while(0)
216 #endif
217 
218 /*
219  * Generic LED platform data for describing LED names and default triggers.
220  */
221 struct led_info {
222 	const char	*name;
223 	const char	*default_trigger;
224 	int		flags;
225 };
226 
227 struct led_platform_data {
228 	int		num_leds;
229 	struct led_info	*leds;
230 };
231 
232 /* For the leds-gpio driver */
233 struct gpio_led {
234 	const char *name;
235 	const char *default_trigger;
236 	unsigned 	gpio;
237 	unsigned	active_low : 1;
238 	unsigned	retain_state_suspended : 1;
239 	unsigned	default_state : 2;
240 	/* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
241 };
242 #define LEDS_GPIO_DEFSTATE_OFF		0
243 #define LEDS_GPIO_DEFSTATE_ON		1
244 #define LEDS_GPIO_DEFSTATE_KEEP		2
245 
246 struct gpio_led_platform_data {
247 	int 		num_leds;
248 	const struct gpio_led *leds;
249 
250 #define GPIO_LED_NO_BLINK_LOW	0	/* No blink GPIO state low */
251 #define GPIO_LED_NO_BLINK_HIGH	1	/* No blink GPIO state high */
252 #define GPIO_LED_BLINK		2	/* Please, blink */
253 	int		(*gpio_blink_set)(unsigned gpio, int state,
254 					unsigned long *delay_on,
255 					unsigned long *delay_off);
256 };
257 
258 struct platform_device *gpio_led_register_device(
259 		int id, const struct gpio_led_platform_data *pdata);
260 
261 enum cpu_led_event {
262 	CPU_LED_IDLE_START,	/* CPU enters idle */
263 	CPU_LED_IDLE_END,	/* CPU idle ends */
264 	CPU_LED_START,		/* Machine starts, especially resume */
265 	CPU_LED_STOP,		/* Machine stops, especially suspend */
266 	CPU_LED_HALTED,		/* Machine shutdown */
267 };
268 #ifdef CONFIG_LEDS_TRIGGER_CPU
269 extern void ledtrig_cpu(enum cpu_led_event evt);
270 #else
271 static inline void ledtrig_cpu(enum cpu_led_event evt)
272 {
273 	return;
274 }
275 #endif
276 
277 #endif		/* __LINUX_LEDS_H_INCLUDED */
278