1 /* SPDX-License-Identifier: GPL-2.0-only */
3 * Driver model for leds and led triggers
5 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
6 * Copyright (C) 2005 Richard Purdie <rpurdie@openedhand.com>
8 #ifndef __LINUX_LEDS_H_INCLUDED
9 #define __LINUX_LEDS_H_INCLUDED
11 #include <linux/device.h>
12 #include <linux/kernfs.h>
13 #include <linux/list.h>
14 #include <linux/mutex.h>
15 #include <linux/rwsem.h>
16 #include <linux/spinlock.h>
17 #include <linux/timer.h>
18 #include <linux/workqueue.h>
35 enum led_brightness brightness
;
36 enum led_brightness max_brightness
;
39 /* Lower 16 bits reflect status */
40 #define LED_SUSPENDED BIT(0)
41 #define LED_UNREGISTERING BIT(1)
42 /* Upper 16 bits reflect control information */
43 #define LED_CORE_SUSPENDRESUME BIT(16)
44 #define LED_SYSFS_DISABLE BIT(17)
45 #define LED_DEV_CAP_FLASH BIT(18)
46 #define LED_HW_PLUGGABLE BIT(19)
47 #define LED_PANIC_INDICATOR BIT(20)
48 #define LED_BRIGHT_HW_CHANGED BIT(21)
49 #define LED_RETAIN_AT_SHUTDOWN BIT(22)
50 #define LED_INIT_DEFAULT_TRIGGER BIT(23)
52 /* set_brightness_work / blink_timer flags, atomic, private. */
53 unsigned long work_flags
;
55 #define LED_BLINK_SW 0
56 #define LED_BLINK_ONESHOT 1
57 #define LED_BLINK_ONESHOT_STOP 2
58 #define LED_BLINK_INVERT 3
59 #define LED_BLINK_BRIGHTNESS_CHANGE 4
60 #define LED_BLINK_DISABLE 5
62 /* Set LED brightness level
63 * Must not sleep. Use brightness_set_blocking for drivers
64 * that can sleep while setting brightness.
66 void (*brightness_set
)(struct led_classdev
*led_cdev
,
67 enum led_brightness brightness
);
69 * Set LED brightness level immediately - it can block the caller for
70 * the time required for accessing a LED device register.
72 int (*brightness_set_blocking
)(struct led_classdev
*led_cdev
,
73 enum led_brightness brightness
);
74 /* Get LED brightness level */
75 enum led_brightness (*brightness_get
)(struct led_classdev
*led_cdev
);
78 * Activate hardware accelerated blink, delays are in milliseconds
79 * and if both are zero then a sensible default should be chosen.
80 * The call should adjust the timings in that case and if it can't
81 * match the values specified exactly.
82 * Deactivate blinking again when the brightness is set to LED_OFF
83 * via the brightness_set() callback.
85 int (*blink_set
)(struct led_classdev
*led_cdev
,
86 unsigned long *delay_on
,
87 unsigned long *delay_off
);
89 int (*pattern_set
)(struct led_classdev
*led_cdev
,
90 struct led_pattern
*pattern
, u32 len
, int repeat
);
91 int (*pattern_clear
)(struct led_classdev
*led_cdev
);
94 const struct attribute_group
**groups
;
96 struct list_head node
; /* LED Device list */
97 const char *default_trigger
; /* Trigger to use */
99 unsigned long blink_delay_on
, blink_delay_off
;
100 struct timer_list blink_timer
;
101 int blink_brightness
;
102 int new_blink_brightness
;
103 void (*flash_resume
)(struct led_classdev
*led_cdev
);
105 struct work_struct set_brightness_work
;
106 int delayed_set_value
;
108 #ifdef CONFIG_LEDS_TRIGGERS
109 /* Protects the trigger data below */
110 struct rw_semaphore trigger_lock
;
112 struct led_trigger
*trigger
;
113 struct list_head trig_list
;
115 /* true if activated - deactivate routine uses it to do cleanup */
119 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
120 int brightness_hw_changed
;
121 struct kernfs_node
*brightness_hw_changed_kn
;
124 /* Ensures consistent access to the LED Flash Class device */
125 struct mutex led_access
;
128 extern int of_led_classdev_register(struct device
*parent
,
129 struct device_node
*np
,
130 struct led_classdev
*led_cdev
);
131 #define led_classdev_register(parent, led_cdev) \
132 of_led_classdev_register(parent, NULL, led_cdev)
133 extern int devm_of_led_classdev_register(struct device
*parent
,
134 struct device_node
*np
,
135 struct led_classdev
*led_cdev
);
136 #define devm_led_classdev_register(parent, led_cdev) \
137 devm_of_led_classdev_register(parent, NULL, led_cdev)
138 extern void led_classdev_unregister(struct led_classdev
*led_cdev
);
139 extern void devm_led_classdev_unregister(struct device
*parent
,
140 struct led_classdev
*led_cdev
);
141 extern void led_classdev_suspend(struct led_classdev
*led_cdev
);
142 extern void led_classdev_resume(struct led_classdev
*led_cdev
);
145 * led_blink_set - set blinking with software fallback
146 * @led_cdev: the LED to start blinking
147 * @delay_on: the time it should be on (in ms)
148 * @delay_off: the time it should ble off (in ms)
150 * This function makes the LED blink, attempting to use the
151 * hardware acceleration if possible, but falling back to
152 * software blinking if there is no hardware blinking or if
153 * the LED refuses the passed values.
155 * Note that if software blinking is active, simply calling
156 * led_cdev->brightness_set() will not stop the blinking,
157 * use led_classdev_brightness_set() instead.
159 extern void led_blink_set(struct led_classdev
*led_cdev
,
160 unsigned long *delay_on
,
161 unsigned long *delay_off
);
163 * led_blink_set_oneshot - do a oneshot software blink
164 * @led_cdev: the LED to start blinking
165 * @delay_on: the time it should be on (in ms)
166 * @delay_off: the time it should ble off (in ms)
167 * @invert: blink off, then on, leaving the led on
169 * This function makes the LED blink one time for delay_on +
170 * delay_off time, ignoring the request if another one-shot
171 * blink is already in progress.
173 * If invert is set, led blinks for delay_off first, then for
174 * delay_on and leave the led on after the on-off cycle.
176 extern void led_blink_set_oneshot(struct led_classdev
*led_cdev
,
177 unsigned long *delay_on
,
178 unsigned long *delay_off
,
181 * led_set_brightness - set LED brightness
182 * @led_cdev: the LED to set
183 * @brightness: the brightness to set it to
185 * Set an LED's brightness, and, if necessary, cancel the
186 * software blink timer that implements blinking when the
187 * hardware doesn't. This function is guaranteed not to sleep.
189 extern void led_set_brightness(struct led_classdev
*led_cdev
,
190 enum led_brightness brightness
);
193 * led_set_brightness_sync - set LED brightness synchronously
194 * @led_cdev: the LED to set
195 * @brightness: the brightness to set it to
197 * Set an LED's brightness immediately. This function will block
198 * the caller for the time required for accessing device registers,
201 * Returns: 0 on success or negative error value on failure
203 extern int led_set_brightness_sync(struct led_classdev
*led_cdev
,
204 enum led_brightness value
);
207 * led_update_brightness - update LED brightness
208 * @led_cdev: the LED to query
210 * Get an LED's current brightness and update led_cdev->brightness
211 * member with the obtained value.
213 * Returns: 0 on success or negative error value on failure
215 extern int led_update_brightness(struct led_classdev
*led_cdev
);
218 * led_get_default_pattern - return default pattern
220 * @led_cdev: the LED to get default pattern for
221 * @size: pointer for storing the number of elements in returned array,
222 * modified only if return != NULL
224 * Return: Allocated array of integers with default pattern from device tree
225 * or NULL. Caller is responsible for kfree().
227 extern u32
*led_get_default_pattern(struct led_classdev
*led_cdev
,
231 * led_sysfs_disable - disable LED sysfs interface
232 * @led_cdev: the LED to set
234 * Disable the led_cdev's sysfs interface.
236 extern void led_sysfs_disable(struct led_classdev
*led_cdev
);
239 * led_sysfs_enable - enable LED sysfs interface
240 * @led_cdev: the LED to set
242 * Enable the led_cdev's sysfs interface.
244 extern void led_sysfs_enable(struct led_classdev
*led_cdev
);
247 * led_sysfs_is_disabled - check if LED sysfs interface is disabled
248 * @led_cdev: the LED to query
250 * Returns: true if the led_cdev's sysfs interface is disabled.
252 static inline bool led_sysfs_is_disabled(struct led_classdev
*led_cdev
)
254 return led_cdev
->flags
& LED_SYSFS_DISABLE
;
260 /* Registration functions for simple triggers */
261 #define DEFINE_LED_TRIGGER(x) static struct led_trigger *x;
262 #define DEFINE_LED_TRIGGER_GLOBAL(x) struct led_trigger *x;
264 #ifdef CONFIG_LEDS_TRIGGERS
266 #define TRIG_NAME_MAX 50
269 /* Trigger Properties */
271 int (*activate
)(struct led_classdev
*led_cdev
);
272 void (*deactivate
)(struct led_classdev
*led_cdev
);
274 /* LEDs under control by this trigger (for simple triggers) */
275 rwlock_t leddev_list_lock
;
276 struct list_head led_cdevs
;
278 /* Link to next registered trigger */
279 struct list_head next_trig
;
281 const struct attribute_group
**groups
;
285 * Currently the attributes in struct led_trigger::groups are added directly to
286 * the LED device. As this might change in the future, the following
287 * macros abstract getting the LED device and its trigger_data from the dev
288 * parameter passed to the attribute accessor functions.
290 #define led_trigger_get_led(dev) ((struct led_classdev *)dev_get_drvdata((dev)))
291 #define led_trigger_get_drvdata(dev) (led_get_trigger_data(led_trigger_get_led(dev)))
293 ssize_t
led_trigger_store(struct device
*dev
, struct device_attribute
*attr
,
294 const char *buf
, size_t count
);
295 ssize_t
led_trigger_show(struct device
*dev
, struct device_attribute
*attr
,
298 /* Registration functions for complex triggers */
299 extern int led_trigger_register(struct led_trigger
*trigger
);
300 extern void led_trigger_unregister(struct led_trigger
*trigger
);
301 extern int devm_led_trigger_register(struct device
*dev
,
302 struct led_trigger
*trigger
);
304 extern void led_trigger_register_simple(const char *name
,
305 struct led_trigger
**trigger
);
306 extern void led_trigger_unregister_simple(struct led_trigger
*trigger
);
307 extern void led_trigger_event(struct led_trigger
*trigger
,
308 enum led_brightness event
);
309 extern void led_trigger_blink(struct led_trigger
*trigger
,
310 unsigned long *delay_on
,
311 unsigned long *delay_off
);
312 extern void led_trigger_blink_oneshot(struct led_trigger
*trigger
,
313 unsigned long *delay_on
,
314 unsigned long *delay_off
,
316 extern void led_trigger_set_default(struct led_classdev
*led_cdev
);
317 extern int led_trigger_set(struct led_classdev
*led_cdev
,
318 struct led_trigger
*trigger
);
319 extern void led_trigger_remove(struct led_classdev
*led_cdev
);
321 static inline void led_set_trigger_data(struct led_classdev
*led_cdev
,
324 led_cdev
->trigger_data
= trigger_data
;
327 static inline void *led_get_trigger_data(struct led_classdev
*led_cdev
)
329 return led_cdev
->trigger_data
;
333 * led_trigger_rename_static - rename a trigger
334 * @name: the new trigger name
335 * @trig: the LED trigger to rename
337 * Change a LED trigger name by copying the string passed in
338 * name into current trigger name, which MUST be large
339 * enough for the new string.
341 * Note that name must NOT point to the same string used
342 * during LED registration, as that could lead to races.
344 * This is meant to be used on triggers with statically
347 extern void led_trigger_rename_static(const char *name
,
348 struct led_trigger
*trig
);
350 #define module_led_trigger(__led_trigger) \
351 module_driver(__led_trigger, led_trigger_register, \
352 led_trigger_unregister)
356 /* Trigger has no members */
357 struct led_trigger
{};
359 /* Trigger inline empty functions */
360 static inline void led_trigger_register_simple(const char *name
,
361 struct led_trigger
**trigger
) {}
362 static inline void led_trigger_unregister_simple(struct led_trigger
*trigger
) {}
363 static inline void led_trigger_event(struct led_trigger
*trigger
,
364 enum led_brightness event
) {}
365 static inline void led_trigger_blink(struct led_trigger
*trigger
,
366 unsigned long *delay_on
,
367 unsigned long *delay_off
) {}
368 static inline void led_trigger_blink_oneshot(struct led_trigger
*trigger
,
369 unsigned long *delay_on
,
370 unsigned long *delay_off
,
372 static inline void led_trigger_set_default(struct led_classdev
*led_cdev
) {}
373 static inline int led_trigger_set(struct led_classdev
*led_cdev
,
374 struct led_trigger
*trigger
)
379 static inline void led_trigger_remove(struct led_classdev
*led_cdev
) {}
380 static inline void led_set_trigger_data(struct led_classdev
*led_cdev
) {}
381 static inline void *led_get_trigger_data(struct led_classdev
*led_cdev
)
386 #endif /* CONFIG_LEDS_TRIGGERS */
388 /* Trigger specific functions */
389 #ifdef CONFIG_LEDS_TRIGGER_DISK
390 extern void ledtrig_disk_activity(bool write
);
392 static inline void ledtrig_disk_activity(bool write
) {}
395 #ifdef CONFIG_LEDS_TRIGGER_MTD
396 extern void ledtrig_mtd_activity(void);
398 static inline void ledtrig_mtd_activity(void) {}
401 #if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
402 extern void ledtrig_flash_ctrl(bool on
);
403 extern void ledtrig_torch_ctrl(bool on
);
405 static inline void ledtrig_flash_ctrl(bool on
) {}
406 static inline void ledtrig_torch_ctrl(bool on
) {}
410 * Generic LED platform data for describing LED names and default triggers.
414 const char *default_trigger
;
418 struct led_platform_data
{
420 struct led_info
*leds
;
424 typedef int (*gpio_blink_set_t
)(struct gpio_desc
*desc
, int state
,
425 unsigned long *delay_on
,
426 unsigned long *delay_off
);
428 /* For the leds-gpio driver */
431 const char *default_trigger
;
433 unsigned active_low
: 1;
434 unsigned retain_state_suspended
: 1;
435 unsigned panic_indicator
: 1;
436 unsigned default_state
: 2;
437 unsigned retain_state_shutdown
: 1;
438 /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
439 struct gpio_desc
*gpiod
;
441 #define LEDS_GPIO_DEFSTATE_OFF 0
442 #define LEDS_GPIO_DEFSTATE_ON 1
443 #define LEDS_GPIO_DEFSTATE_KEEP 2
445 struct gpio_led_platform_data
{
447 const struct gpio_led
*leds
;
449 #define GPIO_LED_NO_BLINK_LOW 0 /* No blink GPIO state low */
450 #define GPIO_LED_NO_BLINK_HIGH 1 /* No blink GPIO state high */
451 #define GPIO_LED_BLINK 2 /* Please, blink */
452 gpio_blink_set_t gpio_blink_set
;
455 #ifdef CONFIG_NEW_LEDS
456 struct platform_device
*gpio_led_register_device(
457 int id
, const struct gpio_led_platform_data
*pdata
);
459 static inline struct platform_device
*gpio_led_register_device(
460 int id
, const struct gpio_led_platform_data
*pdata
)
467 CPU_LED_IDLE_START
, /* CPU enters idle */
468 CPU_LED_IDLE_END
, /* CPU idle ends */
469 CPU_LED_START
, /* Machine starts, especially resume */
470 CPU_LED_STOP
, /* Machine stops, especially suspend */
471 CPU_LED_HALTED
, /* Machine shutdown */
473 #ifdef CONFIG_LEDS_TRIGGER_CPU
474 extern void ledtrig_cpu(enum cpu_led_event evt
);
476 static inline void ledtrig_cpu(enum cpu_led_event evt
)
482 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
483 extern void led_classdev_notify_brightness_hw_changed(
484 struct led_classdev
*led_cdev
, enum led_brightness brightness
);
486 static inline void led_classdev_notify_brightness_hw_changed(
487 struct led_classdev
*led_cdev
, enum led_brightness brightness
) { }
491 * struct led_pattern - pattern interval settings
492 * @delta_t: pattern interval delay, in milliseconds
493 * @brightness: pattern interval brightness
501 LED_AUDIO_MUTE
, /* master mute LED */
502 LED_AUDIO_MICMUTE
, /* mic mute LED */
506 #if IS_ENABLED(CONFIG_LEDS_TRIGGER_AUDIO)
507 enum led_brightness
ledtrig_audio_get(enum led_audio type
);
508 void ledtrig_audio_set(enum led_audio type
, enum led_brightness state
);
510 static inline enum led_brightness
ledtrig_audio_get(enum led_audio type
)
514 static inline void ledtrig_audio_set(enum led_audio type
,
515 enum led_brightness state
)
520 #endif /* __LINUX_LEDS_H_INCLUDED */