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 <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>
35 struct led_init_data {
36 /* device fwnode handle */
37 struct fwnode_handle *fwnode;
39 * default <color:function> tuple, for backward compatibility
40 * with in-driver hard-coded LED names used as a fallback when
41 * DT "label" property is absent; it should be set to NULL
42 * in new LED class drivers.
44 const char *default_label;
46 * string to be used for devicename section of LED class device
47 * either for label based LED name composition path or for fwnode
48 * based when devname_mandatory is true
50 const char *devicename;
52 * indicates if LED name should always comprise devicename section;
53 * only LEDs exposed by drivers of hot-pluggable devices should
56 bool devname_mandatory;
61 enum led_brightness brightness;
62 enum led_brightness max_brightness;
65 /* Lower 16 bits reflect status */
66 #define LED_SUSPENDED BIT(0)
67 #define LED_UNREGISTERING BIT(1)
68 /* Upper 16 bits reflect control information */
69 #define LED_CORE_SUSPENDRESUME BIT(16)
70 #define LED_SYSFS_DISABLE BIT(17)
71 #define LED_DEV_CAP_FLASH BIT(18)
72 #define LED_HW_PLUGGABLE BIT(19)
73 #define LED_PANIC_INDICATOR BIT(20)
74 #define LED_BRIGHT_HW_CHANGED BIT(21)
75 #define LED_RETAIN_AT_SHUTDOWN BIT(22)
76 #define LED_INIT_DEFAULT_TRIGGER BIT(23)
78 /* set_brightness_work / blink_timer flags, atomic, private. */
79 unsigned long work_flags;
81 #define LED_BLINK_SW 0
82 #define LED_BLINK_ONESHOT 1
83 #define LED_BLINK_ONESHOT_STOP 2
84 #define LED_BLINK_INVERT 3
85 #define LED_BLINK_BRIGHTNESS_CHANGE 4
86 #define LED_BLINK_DISABLE 5
88 /* Set LED brightness level
89 * Must not sleep. Use brightness_set_blocking for drivers
90 * that can sleep while setting brightness.
92 void (*brightness_set)(struct led_classdev *led_cdev,
93 enum led_brightness brightness);
95 * Set LED brightness level immediately - it can block the caller for
96 * the time required for accessing a LED device register.
98 int (*brightness_set_blocking)(struct led_classdev *led_cdev,
99 enum led_brightness brightness);
100 /* Get LED brightness level */
101 enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
104 * Activate hardware accelerated blink, delays are in milliseconds
105 * and if both are zero then a sensible default should be chosen.
106 * The call should adjust the timings in that case and if it can't
107 * match the values specified exactly.
108 * Deactivate blinking again when the brightness is set to LED_OFF
109 * via the brightness_set() callback.
111 int (*blink_set)(struct led_classdev *led_cdev,
112 unsigned long *delay_on,
113 unsigned long *delay_off);
115 int (*pattern_set)(struct led_classdev *led_cdev,
116 struct led_pattern *pattern, u32 len, int repeat);
117 int (*pattern_clear)(struct led_classdev *led_cdev);
120 const struct attribute_group **groups;
122 struct list_head node; /* LED Device list */
123 const char *default_trigger; /* Trigger to use */
125 unsigned long blink_delay_on, blink_delay_off;
126 struct timer_list blink_timer;
127 int blink_brightness;
128 int new_blink_brightness;
129 void (*flash_resume)(struct led_classdev *led_cdev);
131 struct work_struct set_brightness_work;
132 int delayed_set_value;
134 #ifdef CONFIG_LEDS_TRIGGERS
135 /* Protects the trigger data below */
136 struct rw_semaphore trigger_lock;
138 struct led_trigger *trigger;
139 struct list_head trig_list;
141 /* true if activated - deactivate routine uses it to do cleanup */
145 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
146 int brightness_hw_changed;
147 struct kernfs_node *brightness_hw_changed_kn;
150 /* Ensures consistent access to the LED Flash Class device */
151 struct mutex led_access;
155 * led_classdev_register_ext - register a new object of LED class with
157 * @parent: LED controller device this LED is driven by
158 * @led_cdev: the led_classdev structure for this device
159 * @init_data: the LED class device initialization data
161 * Register a new object of LED class, with name derived from init_data.
163 * Returns: 0 on success or negative error value on failure
165 int led_classdev_register_ext(struct device *parent,
166 struct led_classdev *led_cdev,
167 struct led_init_data *init_data);
170 * led_classdev_register - register a new object of LED class
171 * @parent: LED controller device this LED is driven by
172 * @led_cdev: the led_classdev structure for this device
174 * Register a new object of LED class, with name derived from the name property
175 * of passed led_cdev argument.
177 * Returns: 0 on success or negative error value on failure
179 static inline int led_classdev_register(struct device *parent,
180 struct led_classdev *led_cdev)
182 return led_classdev_register_ext(parent, led_cdev, NULL);
185 int devm_led_classdev_register_ext(struct device *parent,
186 struct led_classdev *led_cdev,
187 struct led_init_data *init_data);
189 static inline int devm_led_classdev_register(struct device *parent,
190 struct led_classdev *led_cdev)
192 return devm_led_classdev_register_ext(parent, led_cdev, NULL);
194 void led_classdev_unregister(struct led_classdev *led_cdev);
195 void devm_led_classdev_unregister(struct device *parent,
196 struct led_classdev *led_cdev);
197 void led_classdev_suspend(struct led_classdev *led_cdev);
198 void led_classdev_resume(struct led_classdev *led_cdev);
200 extern struct led_classdev *of_led_get(struct device_node *np, int index);
201 extern void led_put(struct led_classdev *led_cdev);
202 struct led_classdev *__must_check devm_of_led_get(struct device *dev,
206 * led_blink_set - set blinking with software fallback
207 * @led_cdev: the LED to start blinking
208 * @delay_on: the time it should be on (in ms)
209 * @delay_off: the time it should ble off (in ms)
211 * This function makes the LED blink, attempting to use the
212 * hardware acceleration if possible, but falling back to
213 * software blinking if there is no hardware blinking or if
214 * the LED refuses the passed values.
216 * Note that if software blinking is active, simply calling
217 * led_cdev->brightness_set() will not stop the blinking,
218 * use led_classdev_brightness_set() instead.
220 void led_blink_set(struct led_classdev *led_cdev, unsigned long *delay_on,
221 unsigned long *delay_off);
223 * led_blink_set_oneshot - do a oneshot software blink
224 * @led_cdev: the LED to start blinking
225 * @delay_on: the time it should be on (in ms)
226 * @delay_off: the time it should ble off (in ms)
227 * @invert: blink off, then on, leaving the led on
229 * This function makes the LED blink one time for delay_on +
230 * delay_off time, ignoring the request if another one-shot
231 * blink is already in progress.
233 * If invert is set, led blinks for delay_off first, then for
234 * delay_on and leave the led on after the on-off cycle.
236 void led_blink_set_oneshot(struct led_classdev *led_cdev,
237 unsigned long *delay_on, unsigned long *delay_off,
240 * led_set_brightness - set LED brightness
241 * @led_cdev: the LED to set
242 * @brightness: the brightness to set it to
244 * Set an LED's brightness, and, if necessary, cancel the
245 * software blink timer that implements blinking when the
246 * hardware doesn't. This function is guaranteed not to sleep.
248 void led_set_brightness(struct led_classdev *led_cdev,
249 enum led_brightness brightness);
252 * led_set_brightness_sync - set LED brightness synchronously
253 * @led_cdev: the LED to set
254 * @value: the brightness to set it to
256 * Set an LED's brightness immediately. This function will block
257 * the caller for the time required for accessing device registers,
260 * Returns: 0 on success or negative error value on failure
262 int led_set_brightness_sync(struct led_classdev *led_cdev,
263 enum led_brightness value);
266 * led_update_brightness - update LED brightness
267 * @led_cdev: the LED to query
269 * Get an LED's current brightness and update led_cdev->brightness
270 * member with the obtained value.
272 * Returns: 0 on success or negative error value on failure
274 int led_update_brightness(struct led_classdev *led_cdev);
277 * led_get_default_pattern - return default pattern
279 * @led_cdev: the LED to get default pattern for
280 * @size: pointer for storing the number of elements in returned array,
281 * modified only if return != NULL
283 * Return: Allocated array of integers with default pattern from device tree
284 * or NULL. Caller is responsible for kfree().
286 u32 *led_get_default_pattern(struct led_classdev *led_cdev, unsigned int *size);
289 * led_sysfs_disable - disable LED sysfs interface
290 * @led_cdev: the LED to set
292 * Disable the led_cdev's sysfs interface.
294 void led_sysfs_disable(struct led_classdev *led_cdev);
297 * led_sysfs_enable - enable LED sysfs interface
298 * @led_cdev: the LED to set
300 * Enable the led_cdev's sysfs interface.
302 void led_sysfs_enable(struct led_classdev *led_cdev);
305 * led_compose_name - compose LED class device name
306 * @dev: LED controller device object
307 * @init_data: the LED class device initialization data
308 * @led_classdev_name: composed LED class device name
310 * Create LED class device name basing on the provided init_data argument.
311 * The name can have <devicename:color:function> or <color:function>.
312 * form, depending on the init_data configuration.
314 * Returns: 0 on success or negative error value on failure
316 int led_compose_name(struct device *dev, struct led_init_data *init_data,
317 char *led_classdev_name);
320 * led_sysfs_is_disabled - check if LED sysfs interface is disabled
321 * @led_cdev: the LED to query
323 * Returns: true if the led_cdev's sysfs interface is disabled.
325 static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
327 return led_cdev->flags & LED_SYSFS_DISABLE;
333 /* Registration functions for simple triggers */
334 #define DEFINE_LED_TRIGGER(x) static struct led_trigger *x;
335 #define DEFINE_LED_TRIGGER_GLOBAL(x) struct led_trigger *x;
337 #ifdef CONFIG_LEDS_TRIGGERS
339 #define TRIG_NAME_MAX 50
342 /* Trigger Properties */
344 int (*activate)(struct led_classdev *led_cdev);
345 void (*deactivate)(struct led_classdev *led_cdev);
347 /* LEDs under control by this trigger (for simple triggers) */
348 rwlock_t leddev_list_lock;
349 struct list_head led_cdevs;
351 /* Link to next registered trigger */
352 struct list_head next_trig;
354 const struct attribute_group **groups;
358 * Currently the attributes in struct led_trigger::groups are added directly to
359 * the LED device. As this might change in the future, the following
360 * macros abstract getting the LED device and its trigger_data from the dev
361 * parameter passed to the attribute accessor functions.
363 #define led_trigger_get_led(dev) ((struct led_classdev *)dev_get_drvdata((dev)))
364 #define led_trigger_get_drvdata(dev) (led_get_trigger_data(led_trigger_get_led(dev)))
366 /* Registration functions for complex triggers */
367 int led_trigger_register(struct led_trigger *trigger);
368 void led_trigger_unregister(struct led_trigger *trigger);
369 int devm_led_trigger_register(struct device *dev,
370 struct led_trigger *trigger);
372 void led_trigger_register_simple(const char *name,
373 struct led_trigger **trigger);
374 void led_trigger_unregister_simple(struct led_trigger *trigger);
375 void led_trigger_event(struct led_trigger *trigger, enum led_brightness event);
376 void led_trigger_blink(struct led_trigger *trigger, unsigned long *delay_on,
377 unsigned long *delay_off);
378 void led_trigger_blink_oneshot(struct led_trigger *trigger,
379 unsigned long *delay_on,
380 unsigned long *delay_off,
382 void led_trigger_set_default(struct led_classdev *led_cdev);
383 int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger);
384 void led_trigger_remove(struct led_classdev *led_cdev);
386 static inline void led_set_trigger_data(struct led_classdev *led_cdev,
389 led_cdev->trigger_data = trigger_data;
392 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
394 return led_cdev->trigger_data;
398 * led_trigger_rename_static - rename a trigger
399 * @name: the new trigger name
400 * @trig: the LED trigger to rename
402 * Change a LED trigger name by copying the string passed in
403 * name into current trigger name, which MUST be large
404 * enough for the new string.
406 * Note that name must NOT point to the same string used
407 * during LED registration, as that could lead to races.
409 * This is meant to be used on triggers with statically
412 void led_trigger_rename_static(const char *name, struct led_trigger *trig);
414 #define module_led_trigger(__led_trigger) \
415 module_driver(__led_trigger, led_trigger_register, \
416 led_trigger_unregister)
420 /* Trigger has no members */
421 struct led_trigger {};
423 /* Trigger inline empty functions */
424 static inline void led_trigger_register_simple(const char *name,
425 struct led_trigger **trigger) {}
426 static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
427 static inline void led_trigger_event(struct led_trigger *trigger,
428 enum led_brightness event) {}
429 static inline void led_trigger_blink(struct led_trigger *trigger,
430 unsigned long *delay_on,
431 unsigned long *delay_off) {}
432 static inline void led_trigger_blink_oneshot(struct led_trigger *trigger,
433 unsigned long *delay_on,
434 unsigned long *delay_off,
436 static inline void led_trigger_set_default(struct led_classdev *led_cdev) {}
437 static inline int led_trigger_set(struct led_classdev *led_cdev,
438 struct led_trigger *trigger)
443 static inline void led_trigger_remove(struct led_classdev *led_cdev) {}
444 static inline void led_set_trigger_data(struct led_classdev *led_cdev) {}
445 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
450 #endif /* CONFIG_LEDS_TRIGGERS */
452 /* Trigger specific functions */
453 #ifdef CONFIG_LEDS_TRIGGER_DISK
454 void ledtrig_disk_activity(bool write);
456 static inline void ledtrig_disk_activity(bool write) {}
459 #ifdef CONFIG_LEDS_TRIGGER_MTD
460 void ledtrig_mtd_activity(void);
462 static inline void ledtrig_mtd_activity(void) {}
465 #if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
466 void ledtrig_flash_ctrl(bool on);
467 void ledtrig_torch_ctrl(bool on);
469 static inline void ledtrig_flash_ctrl(bool on) {}
470 static inline void ledtrig_torch_ctrl(bool on) {}
474 * Generic LED platform data for describing LED names and default triggers.
478 const char *default_trigger;
482 struct led_platform_data {
484 struct led_info *leds;
487 struct led_properties {
490 const char *function;
492 bool func_enum_present;
497 typedef int (*gpio_blink_set_t)(struct gpio_desc *desc, int state,
498 unsigned long *delay_on,
499 unsigned long *delay_off);
501 /* For the leds-gpio driver */
504 const char *default_trigger;
506 unsigned active_low : 1;
507 unsigned retain_state_suspended : 1;
508 unsigned panic_indicator : 1;
509 unsigned default_state : 2;
510 unsigned retain_state_shutdown : 1;
511 /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
512 struct gpio_desc *gpiod;
514 #define LEDS_GPIO_DEFSTATE_OFF 0
515 #define LEDS_GPIO_DEFSTATE_ON 1
516 #define LEDS_GPIO_DEFSTATE_KEEP 2
518 struct gpio_led_platform_data {
520 const struct gpio_led *leds;
522 #define GPIO_LED_NO_BLINK_LOW 0 /* No blink GPIO state low */
523 #define GPIO_LED_NO_BLINK_HIGH 1 /* No blink GPIO state high */
524 #define GPIO_LED_BLINK 2 /* Please, blink */
525 gpio_blink_set_t gpio_blink_set;
528 #ifdef CONFIG_NEW_LEDS
529 struct platform_device *gpio_led_register_device(
530 int id, const struct gpio_led_platform_data *pdata);
532 static inline struct platform_device *gpio_led_register_device(
533 int id, const struct gpio_led_platform_data *pdata)
540 CPU_LED_IDLE_START, /* CPU enters idle */
541 CPU_LED_IDLE_END, /* CPU idle ends */
542 CPU_LED_START, /* Machine starts, especially resume */
543 CPU_LED_STOP, /* Machine stops, especially suspend */
544 CPU_LED_HALTED, /* Machine shutdown */
546 #ifdef CONFIG_LEDS_TRIGGER_CPU
547 void ledtrig_cpu(enum cpu_led_event evt);
549 static inline void ledtrig_cpu(enum cpu_led_event evt)
555 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
556 void led_classdev_notify_brightness_hw_changed(
557 struct led_classdev *led_cdev, enum led_brightness brightness);
559 static inline void led_classdev_notify_brightness_hw_changed(
560 struct led_classdev *led_cdev, enum led_brightness brightness) { }
564 * struct led_pattern - pattern interval settings
565 * @delta_t: pattern interval delay, in milliseconds
566 * @brightness: pattern interval brightness
574 LED_AUDIO_MUTE, /* master mute LED */
575 LED_AUDIO_MICMUTE, /* mic mute LED */
579 #if IS_ENABLED(CONFIG_LEDS_TRIGGER_AUDIO)
580 enum led_brightness ledtrig_audio_get(enum led_audio type);
581 void ledtrig_audio_set(enum led_audio type, enum led_brightness state);
583 static inline enum led_brightness ledtrig_audio_get(enum led_audio type)
587 static inline void ledtrig_audio_set(enum led_audio type,
588 enum led_brightness state)
593 #endif /* __LINUX_LEDS_H_INCLUDED */