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>
33 struct led_init_data {
34 /* device fwnode handle */
35 struct fwnode_handle *fwnode;
40 enum led_brightness brightness;
41 enum led_brightness max_brightness;
44 /* Lower 16 bits reflect status */
45 #define LED_SUSPENDED BIT(0)
46 #define LED_UNREGISTERING BIT(1)
47 /* Upper 16 bits reflect control information */
48 #define LED_CORE_SUSPENDRESUME BIT(16)
49 #define LED_SYSFS_DISABLE BIT(17)
50 #define LED_DEV_CAP_FLASH BIT(18)
51 #define LED_HW_PLUGGABLE BIT(19)
52 #define LED_PANIC_INDICATOR BIT(20)
53 #define LED_BRIGHT_HW_CHANGED BIT(21)
54 #define LED_RETAIN_AT_SHUTDOWN BIT(22)
55 #define LED_INIT_DEFAULT_TRIGGER BIT(23)
57 /* set_brightness_work / blink_timer flags, atomic, private. */
58 unsigned long work_flags;
60 #define LED_BLINK_SW 0
61 #define LED_BLINK_ONESHOT 1
62 #define LED_BLINK_ONESHOT_STOP 2
63 #define LED_BLINK_INVERT 3
64 #define LED_BLINK_BRIGHTNESS_CHANGE 4
65 #define LED_BLINK_DISABLE 5
67 /* Set LED brightness level
68 * Must not sleep. Use brightness_set_blocking for drivers
69 * that can sleep while setting brightness.
71 void (*brightness_set)(struct led_classdev *led_cdev,
72 enum led_brightness brightness);
74 * Set LED brightness level immediately - it can block the caller for
75 * the time required for accessing a LED device register.
77 int (*brightness_set_blocking)(struct led_classdev *led_cdev,
78 enum led_brightness brightness);
79 /* Get LED brightness level */
80 enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
83 * Activate hardware accelerated blink, delays are in milliseconds
84 * and if both are zero then a sensible default should be chosen.
85 * The call should adjust the timings in that case and if it can't
86 * match the values specified exactly.
87 * Deactivate blinking again when the brightness is set to LED_OFF
88 * via the brightness_set() callback.
90 int (*blink_set)(struct led_classdev *led_cdev,
91 unsigned long *delay_on,
92 unsigned long *delay_off);
94 int (*pattern_set)(struct led_classdev *led_cdev,
95 struct led_pattern *pattern, u32 len, int repeat);
96 int (*pattern_clear)(struct led_classdev *led_cdev);
99 const struct attribute_group **groups;
101 struct list_head node; /* LED Device list */
102 const char *default_trigger; /* Trigger to use */
104 unsigned long blink_delay_on, blink_delay_off;
105 struct timer_list blink_timer;
106 int blink_brightness;
107 int new_blink_brightness;
108 void (*flash_resume)(struct led_classdev *led_cdev);
110 struct work_struct set_brightness_work;
111 int delayed_set_value;
113 #ifdef CONFIG_LEDS_TRIGGERS
114 /* Protects the trigger data below */
115 struct rw_semaphore trigger_lock;
117 struct led_trigger *trigger;
118 struct list_head trig_list;
120 /* true if activated - deactivate routine uses it to do cleanup */
124 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
125 int brightness_hw_changed;
126 struct kernfs_node *brightness_hw_changed_kn;
129 /* Ensures consistent access to the LED Flash Class device */
130 struct mutex led_access;
134 * led_classdev_register_ext - register a new object of LED class with
136 * @parent: LED controller device this LED is driven by
137 * @led_cdev: the led_classdev structure for this device
138 * @init_data: the LED class device initialization data
140 * Returns: 0 on success or negative error value on failure
142 extern int led_classdev_register_ext(struct device *parent,
143 struct led_classdev *led_cdev,
144 struct led_init_data *init_data);
145 #define led_classdev_register(parent, led_cdev) \
146 led_classdev_register_ext(parent, led_cdev, NULL)
147 extern int devm_led_classdev_register_ext(struct device *parent,
148 struct led_classdev *led_cdev,
149 struct led_init_data *init_data);
150 #define devm_led_classdev_register(parent, led_cdev) \
151 devm_led_classdev_register_ext(parent, led_cdev, NULL)
152 extern void led_classdev_unregister(struct led_classdev *led_cdev);
153 extern void devm_led_classdev_unregister(struct device *parent,
154 struct led_classdev *led_cdev);
155 extern void led_classdev_suspend(struct led_classdev *led_cdev);
156 extern void led_classdev_resume(struct led_classdev *led_cdev);
159 * led_blink_set - set blinking with software fallback
160 * @led_cdev: the LED to start blinking
161 * @delay_on: the time it should be on (in ms)
162 * @delay_off: the time it should ble off (in ms)
164 * This function makes the LED blink, attempting to use the
165 * hardware acceleration if possible, but falling back to
166 * software blinking if there is no hardware blinking or if
167 * the LED refuses the passed values.
169 * Note that if software blinking is active, simply calling
170 * led_cdev->brightness_set() will not stop the blinking,
171 * use led_classdev_brightness_set() instead.
173 extern void led_blink_set(struct led_classdev *led_cdev,
174 unsigned long *delay_on,
175 unsigned long *delay_off);
177 * led_blink_set_oneshot - do a oneshot software blink
178 * @led_cdev: the LED to start blinking
179 * @delay_on: the time it should be on (in ms)
180 * @delay_off: the time it should ble off (in ms)
181 * @invert: blink off, then on, leaving the led on
183 * This function makes the LED blink one time for delay_on +
184 * delay_off time, ignoring the request if another one-shot
185 * blink is already in progress.
187 * If invert is set, led blinks for delay_off first, then for
188 * delay_on and leave the led on after the on-off cycle.
190 extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
191 unsigned long *delay_on,
192 unsigned long *delay_off,
195 * led_set_brightness - set LED brightness
196 * @led_cdev: the LED to set
197 * @brightness: the brightness to set it to
199 * Set an LED's brightness, and, if necessary, cancel the
200 * software blink timer that implements blinking when the
201 * hardware doesn't. This function is guaranteed not to sleep.
203 extern void led_set_brightness(struct led_classdev *led_cdev,
204 enum led_brightness brightness);
207 * led_set_brightness_sync - set LED brightness synchronously
208 * @led_cdev: the LED to set
209 * @brightness: the brightness to set it to
211 * Set an LED's brightness immediately. This function will block
212 * the caller for the time required for accessing device registers,
215 * Returns: 0 on success or negative error value on failure
217 extern int led_set_brightness_sync(struct led_classdev *led_cdev,
218 enum led_brightness value);
221 * led_update_brightness - update LED brightness
222 * @led_cdev: the LED to query
224 * Get an LED's current brightness and update led_cdev->brightness
225 * member with the obtained value.
227 * Returns: 0 on success or negative error value on failure
229 extern int led_update_brightness(struct led_classdev *led_cdev);
232 * led_get_default_pattern - return default pattern
234 * @led_cdev: the LED to get default pattern for
235 * @size: pointer for storing the number of elements in returned array,
236 * modified only if return != NULL
238 * Return: Allocated array of integers with default pattern from device tree
239 * or NULL. Caller is responsible for kfree().
241 extern u32 *led_get_default_pattern(struct led_classdev *led_cdev,
245 * led_sysfs_disable - disable LED sysfs interface
246 * @led_cdev: the LED to set
248 * Disable the led_cdev's sysfs interface.
250 extern void led_sysfs_disable(struct led_classdev *led_cdev);
253 * led_sysfs_enable - enable LED sysfs interface
254 * @led_cdev: the LED to set
256 * Enable the led_cdev's sysfs interface.
258 extern void led_sysfs_enable(struct led_classdev *led_cdev);
261 * led_sysfs_is_disabled - check if LED sysfs interface is disabled
262 * @led_cdev: the LED to query
264 * Returns: true if the led_cdev's sysfs interface is disabled.
266 static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
268 return led_cdev->flags & LED_SYSFS_DISABLE;
274 /* Registration functions for simple triggers */
275 #define DEFINE_LED_TRIGGER(x) static struct led_trigger *x;
276 #define DEFINE_LED_TRIGGER_GLOBAL(x) struct led_trigger *x;
278 #ifdef CONFIG_LEDS_TRIGGERS
280 #define TRIG_NAME_MAX 50
283 /* Trigger Properties */
285 int (*activate)(struct led_classdev *led_cdev);
286 void (*deactivate)(struct led_classdev *led_cdev);
288 /* LEDs under control by this trigger (for simple triggers) */
289 rwlock_t leddev_list_lock;
290 struct list_head led_cdevs;
292 /* Link to next registered trigger */
293 struct list_head next_trig;
295 const struct attribute_group **groups;
299 * Currently the attributes in struct led_trigger::groups are added directly to
300 * the LED device. As this might change in the future, the following
301 * macros abstract getting the LED device and its trigger_data from the dev
302 * parameter passed to the attribute accessor functions.
304 #define led_trigger_get_led(dev) ((struct led_classdev *)dev_get_drvdata((dev)))
305 #define led_trigger_get_drvdata(dev) (led_get_trigger_data(led_trigger_get_led(dev)))
307 ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
308 const char *buf, size_t count);
309 ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
312 /* Registration functions for complex triggers */
313 extern int led_trigger_register(struct led_trigger *trigger);
314 extern void led_trigger_unregister(struct led_trigger *trigger);
315 extern int devm_led_trigger_register(struct device *dev,
316 struct led_trigger *trigger);
318 extern void led_trigger_register_simple(const char *name,
319 struct led_trigger **trigger);
320 extern void led_trigger_unregister_simple(struct led_trigger *trigger);
321 extern void led_trigger_event(struct led_trigger *trigger,
322 enum led_brightness event);
323 extern void led_trigger_blink(struct led_trigger *trigger,
324 unsigned long *delay_on,
325 unsigned long *delay_off);
326 extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
327 unsigned long *delay_on,
328 unsigned long *delay_off,
330 extern void led_trigger_set_default(struct led_classdev *led_cdev);
331 extern int led_trigger_set(struct led_classdev *led_cdev,
332 struct led_trigger *trigger);
333 extern void led_trigger_remove(struct led_classdev *led_cdev);
335 static inline void led_set_trigger_data(struct led_classdev *led_cdev,
338 led_cdev->trigger_data = trigger_data;
341 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
343 return led_cdev->trigger_data;
347 * led_trigger_rename_static - rename a trigger
348 * @name: the new trigger name
349 * @trig: the LED trigger to rename
351 * Change a LED trigger name by copying the string passed in
352 * name into current trigger name, which MUST be large
353 * enough for the new string.
355 * Note that name must NOT point to the same string used
356 * during LED registration, as that could lead to races.
358 * This is meant to be used on triggers with statically
361 extern void led_trigger_rename_static(const char *name,
362 struct led_trigger *trig);
364 #define module_led_trigger(__led_trigger) \
365 module_driver(__led_trigger, led_trigger_register, \
366 led_trigger_unregister)
370 /* Trigger has no members */
371 struct led_trigger {};
373 /* Trigger inline empty functions */
374 static inline void led_trigger_register_simple(const char *name,
375 struct led_trigger **trigger) {}
376 static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
377 static inline void led_trigger_event(struct led_trigger *trigger,
378 enum led_brightness event) {}
379 static inline void led_trigger_blink(struct led_trigger *trigger,
380 unsigned long *delay_on,
381 unsigned long *delay_off) {}
382 static inline void led_trigger_blink_oneshot(struct led_trigger *trigger,
383 unsigned long *delay_on,
384 unsigned long *delay_off,
386 static inline void led_trigger_set_default(struct led_classdev *led_cdev) {}
387 static inline int led_trigger_set(struct led_classdev *led_cdev,
388 struct led_trigger *trigger)
393 static inline void led_trigger_remove(struct led_classdev *led_cdev) {}
394 static inline void led_set_trigger_data(struct led_classdev *led_cdev) {}
395 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
400 #endif /* CONFIG_LEDS_TRIGGERS */
402 /* Trigger specific functions */
403 #ifdef CONFIG_LEDS_TRIGGER_DISK
404 extern void ledtrig_disk_activity(bool write);
406 static inline void ledtrig_disk_activity(bool write) {}
409 #ifdef CONFIG_LEDS_TRIGGER_MTD
410 extern void ledtrig_mtd_activity(void);
412 static inline void ledtrig_mtd_activity(void) {}
415 #if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
416 extern void ledtrig_flash_ctrl(bool on);
417 extern void ledtrig_torch_ctrl(bool on);
419 static inline void ledtrig_flash_ctrl(bool on) {}
420 static inline void ledtrig_torch_ctrl(bool on) {}
424 * Generic LED platform data for describing LED names and default triggers.
428 const char *default_trigger;
432 struct led_platform_data {
434 struct led_info *leds;
438 typedef int (*gpio_blink_set_t)(struct gpio_desc *desc, int state,
439 unsigned long *delay_on,
440 unsigned long *delay_off);
442 /* For the leds-gpio driver */
445 const char *default_trigger;
447 unsigned active_low : 1;
448 unsigned retain_state_suspended : 1;
449 unsigned panic_indicator : 1;
450 unsigned default_state : 2;
451 unsigned retain_state_shutdown : 1;
452 /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
453 struct gpio_desc *gpiod;
455 #define LEDS_GPIO_DEFSTATE_OFF 0
456 #define LEDS_GPIO_DEFSTATE_ON 1
457 #define LEDS_GPIO_DEFSTATE_KEEP 2
459 struct gpio_led_platform_data {
461 const struct gpio_led *leds;
463 #define GPIO_LED_NO_BLINK_LOW 0 /* No blink GPIO state low */
464 #define GPIO_LED_NO_BLINK_HIGH 1 /* No blink GPIO state high */
465 #define GPIO_LED_BLINK 2 /* Please, blink */
466 gpio_blink_set_t gpio_blink_set;
469 #ifdef CONFIG_NEW_LEDS
470 struct platform_device *gpio_led_register_device(
471 int id, const struct gpio_led_platform_data *pdata);
473 static inline struct platform_device *gpio_led_register_device(
474 int id, const struct gpio_led_platform_data *pdata)
481 CPU_LED_IDLE_START, /* CPU enters idle */
482 CPU_LED_IDLE_END, /* CPU idle ends */
483 CPU_LED_START, /* Machine starts, especially resume */
484 CPU_LED_STOP, /* Machine stops, especially suspend */
485 CPU_LED_HALTED, /* Machine shutdown */
487 #ifdef CONFIG_LEDS_TRIGGER_CPU
488 extern void ledtrig_cpu(enum cpu_led_event evt);
490 static inline void ledtrig_cpu(enum cpu_led_event evt)
496 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
497 extern void led_classdev_notify_brightness_hw_changed(
498 struct led_classdev *led_cdev, enum led_brightness brightness);
500 static inline void led_classdev_notify_brightness_hw_changed(
501 struct led_classdev *led_cdev, enum led_brightness brightness) { }
505 * struct led_pattern - pattern interval settings
506 * @delta_t: pattern interval delay, in milliseconds
507 * @brightness: pattern interval brightness
515 LED_AUDIO_MUTE, /* master mute LED */
516 LED_AUDIO_MICMUTE, /* mic mute LED */
520 #if IS_ENABLED(CONFIG_LEDS_TRIGGER_AUDIO)
521 enum led_brightness ledtrig_audio_get(enum led_audio type);
522 void ledtrig_audio_set(enum led_audio type, enum led_brightness state);
524 static inline enum led_brightness ledtrig_audio_get(enum led_audio type)
528 static inline void ledtrig_audio_set(enum led_audio type,
529 enum led_brightness state)
534 #endif /* __LINUX_LEDS_H_INCLUDED */