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>
28 /* This is obsolete/useless. We now support variable maximum brightness. */
36 enum led_default_state {
37 LEDS_DEFSTATE_OFF = 0,
39 LEDS_DEFSTATE_KEEP = 2,
42 struct led_init_data {
43 /* device fwnode handle */
44 struct fwnode_handle *fwnode;
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.
51 const char *default_label;
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
57 const char *devicename;
59 * indicates if LED name should always comprise devicename section;
60 * only LEDs exposed by drivers of hot-pluggable devices should
63 bool devname_mandatory;
66 struct led_hw_trigger_type {
72 unsigned int brightness;
73 unsigned int max_brightness;
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 /* Additions for Raspberry Pi PWR LED */
89 #define SET_GPIO_INPUT BIT(30)
90 #define SET_GPIO_OUTPUT BIT(31)
92 /* set_brightness_work / blink_timer flags, atomic, private. */
93 unsigned long work_flags;
95 #define LED_BLINK_SW 0
96 #define LED_BLINK_ONESHOT 1
97 #define LED_BLINK_ONESHOT_STOP 2
98 #define LED_BLINK_INVERT 3
99 #define LED_BLINK_BRIGHTNESS_CHANGE 4
100 #define LED_BLINK_DISABLE 5
102 /* Set LED brightness level
103 * Must not sleep. Use brightness_set_blocking for drivers
104 * that can sleep while setting brightness.
106 void (*brightness_set)(struct led_classdev *led_cdev,
107 enum led_brightness brightness);
109 * Set LED brightness level immediately - it can block the caller for
110 * the time required for accessing a LED device register.
112 int (*brightness_set_blocking)(struct led_classdev *led_cdev,
113 enum led_brightness brightness);
114 /* Get LED brightness level */
115 enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
118 * Activate hardware accelerated blink, delays are in milliseconds
119 * and if both are zero then a sensible default should be chosen.
120 * The call should adjust the timings in that case and if it can't
121 * match the values specified exactly.
122 * Deactivate blinking again when the brightness is set to LED_OFF
123 * via the brightness_set() callback.
125 int (*blink_set)(struct led_classdev *led_cdev,
126 unsigned long *delay_on,
127 unsigned long *delay_off);
129 int (*pattern_set)(struct led_classdev *led_cdev,
130 struct led_pattern *pattern, u32 len, int repeat);
131 int (*pattern_clear)(struct led_classdev *led_cdev);
134 const struct attribute_group **groups;
136 struct list_head node; /* LED Device list */
137 const char *default_trigger; /* Trigger to use */
139 unsigned long blink_delay_on, blink_delay_off;
140 struct timer_list blink_timer;
141 int blink_brightness;
142 int new_blink_brightness;
143 void (*flash_resume)(struct led_classdev *led_cdev);
145 struct work_struct set_brightness_work;
146 int delayed_set_value;
148 #ifdef CONFIG_LEDS_TRIGGERS
149 /* Protects the trigger data below */
150 struct rw_semaphore trigger_lock;
152 struct led_trigger *trigger;
153 struct list_head trig_list;
155 /* true if activated - deactivate routine uses it to do cleanup */
158 /* LEDs that have private triggers have this set */
159 struct led_hw_trigger_type *trigger_type;
162 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
163 int brightness_hw_changed;
164 struct kernfs_node *brightness_hw_changed_kn;
167 /* Ensures consistent access to the LED Flash Class device */
168 struct mutex led_access;
172 * led_classdev_register_ext - register a new object of LED class with
174 * @parent: LED controller device this LED is driven by
175 * @led_cdev: the led_classdev structure for this device
176 * @init_data: the LED class device initialization data
178 * Register a new object of LED class, with name derived from init_data.
180 * Returns: 0 on success or negative error value on failure
182 int led_classdev_register_ext(struct device *parent,
183 struct led_classdev *led_cdev,
184 struct led_init_data *init_data);
187 * led_classdev_register - register a new object of LED class
188 * @parent: LED controller device this LED is driven by
189 * @led_cdev: the led_classdev structure for this device
191 * Register a new object of LED class, with name derived from the name property
192 * of passed led_cdev argument.
194 * Returns: 0 on success or negative error value on failure
196 static inline int led_classdev_register(struct device *parent,
197 struct led_classdev *led_cdev)
199 return led_classdev_register_ext(parent, led_cdev, NULL);
202 int devm_led_classdev_register_ext(struct device *parent,
203 struct led_classdev *led_cdev,
204 struct led_init_data *init_data);
206 static inline int devm_led_classdev_register(struct device *parent,
207 struct led_classdev *led_cdev)
209 return devm_led_classdev_register_ext(parent, led_cdev, NULL);
211 void led_classdev_unregister(struct led_classdev *led_cdev);
212 void devm_led_classdev_unregister(struct device *parent,
213 struct led_classdev *led_cdev);
214 void led_classdev_suspend(struct led_classdev *led_cdev);
215 void led_classdev_resume(struct led_classdev *led_cdev);
217 extern struct led_classdev *of_led_get(struct device_node *np, int index);
218 extern void led_put(struct led_classdev *led_cdev);
219 struct led_classdev *__must_check devm_of_led_get(struct device *dev,
223 * led_blink_set - set blinking with software fallback
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)
228 * This function makes the LED blink, attempting to use the
229 * hardware acceleration if possible, but falling back to
230 * software blinking if there is no hardware blinking or if
231 * the LED refuses the passed values.
233 * Note that if software blinking is active, simply calling
234 * led_cdev->brightness_set() will not stop the blinking,
235 * use led_classdev_brightness_set() instead.
237 void led_blink_set(struct led_classdev *led_cdev, unsigned long *delay_on,
238 unsigned long *delay_off);
240 * led_blink_set_oneshot - do a oneshot software blink
241 * @led_cdev: the LED to start blinking
242 * @delay_on: the time it should be on (in ms)
243 * @delay_off: the time it should ble off (in ms)
244 * @invert: blink off, then on, leaving the led on
246 * This function makes the LED blink one time for delay_on +
247 * delay_off time, ignoring the request if another one-shot
248 * blink is already in progress.
250 * If invert is set, led blinks for delay_off first, then for
251 * delay_on and leave the led on after the on-off cycle.
253 void led_blink_set_oneshot(struct led_classdev *led_cdev,
254 unsigned long *delay_on, unsigned long *delay_off,
257 * led_set_brightness - set LED brightness
258 * @led_cdev: the LED to set
259 * @brightness: the brightness to set it to
261 * Set an LED's brightness, and, if necessary, cancel the
262 * software blink timer that implements blinking when the
263 * hardware doesn't. This function is guaranteed not to sleep.
265 void led_set_brightness(struct led_classdev *led_cdev, unsigned int brightness);
268 * led_set_brightness_sync - set LED brightness synchronously
269 * @led_cdev: the LED to set
270 * @value: the brightness to set it to
272 * Set an LED's brightness immediately. This function will block
273 * the caller for the time required for accessing device registers,
276 * Returns: 0 on success or negative error value on failure
278 int led_set_brightness_sync(struct led_classdev *led_cdev, unsigned int value);
281 * led_update_brightness - update LED brightness
282 * @led_cdev: the LED to query
284 * Get an LED's current brightness and update led_cdev->brightness
285 * member with the obtained value.
287 * Returns: 0 on success or negative error value on failure
289 int led_update_brightness(struct led_classdev *led_cdev);
292 * led_get_default_pattern - return default pattern
294 * @led_cdev: the LED to get default pattern for
295 * @size: pointer for storing the number of elements in returned array,
296 * modified only if return != NULL
298 * Return: Allocated array of integers with default pattern from device tree
299 * or NULL. Caller is responsible for kfree().
301 u32 *led_get_default_pattern(struct led_classdev *led_cdev, unsigned int *size);
304 * led_sysfs_disable - disable LED sysfs interface
305 * @led_cdev: the LED to set
307 * Disable the led_cdev's sysfs interface.
309 void led_sysfs_disable(struct led_classdev *led_cdev);
312 * led_sysfs_enable - enable LED sysfs interface
313 * @led_cdev: the LED to set
315 * Enable the led_cdev's sysfs interface.
317 void led_sysfs_enable(struct led_classdev *led_cdev);
320 * led_compose_name - compose LED class device name
321 * @dev: LED controller device object
322 * @init_data: the LED class device initialization data
323 * @led_classdev_name: composed LED class device name
325 * Create LED class device name basing on the provided init_data argument.
326 * The name can have <devicename:color:function> or <color:function>.
327 * form, depending on the init_data configuration.
329 * Returns: 0 on success or negative error value on failure
331 int led_compose_name(struct device *dev, struct led_init_data *init_data,
332 char *led_classdev_name);
335 * led_sysfs_is_disabled - check if LED sysfs interface is disabled
336 * @led_cdev: the LED to query
338 * Returns: true if the led_cdev's sysfs interface is disabled.
340 static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
342 return led_cdev->flags & LED_SYSFS_DISABLE;
348 /* Registration functions for simple triggers */
349 #define DEFINE_LED_TRIGGER(x) static struct led_trigger *x;
350 #define DEFINE_LED_TRIGGER_GLOBAL(x) struct led_trigger *x;
352 #ifdef CONFIG_LEDS_TRIGGERS
354 #define TRIG_NAME_MAX 50
357 /* Trigger Properties */
359 int (*activate)(struct led_classdev *led_cdev);
360 void (*deactivate)(struct led_classdev *led_cdev);
362 /* LED-private triggers have this set */
363 struct led_hw_trigger_type *trigger_type;
365 /* LEDs under control by this trigger (for simple triggers) */
366 rwlock_t leddev_list_lock;
367 struct list_head led_cdevs;
369 /* Link to next registered trigger */
370 struct list_head next_trig;
372 const struct attribute_group **groups;
376 * Currently the attributes in struct led_trigger::groups are added directly to
377 * the LED device. As this might change in the future, the following
378 * macros abstract getting the LED device and its trigger_data from the dev
379 * parameter passed to the attribute accessor functions.
381 #define led_trigger_get_led(dev) ((struct led_classdev *)dev_get_drvdata((dev)))
382 #define led_trigger_get_drvdata(dev) (led_get_trigger_data(led_trigger_get_led(dev)))
384 /* Registration functions for complex triggers */
385 int led_trigger_register(struct led_trigger *trigger);
386 void led_trigger_unregister(struct led_trigger *trigger);
387 int devm_led_trigger_register(struct device *dev,
388 struct led_trigger *trigger);
390 void led_trigger_register_simple(const char *name,
391 struct led_trigger **trigger);
392 void led_trigger_unregister_simple(struct led_trigger *trigger);
393 void led_trigger_event(struct led_trigger *trigger, enum led_brightness event);
394 void led_trigger_blink(struct led_trigger *trigger, unsigned long *delay_on,
395 unsigned long *delay_off);
396 void led_trigger_blink_oneshot(struct led_trigger *trigger,
397 unsigned long *delay_on,
398 unsigned long *delay_off,
400 void led_trigger_set_default(struct led_classdev *led_cdev);
401 int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger);
402 void led_trigger_remove(struct led_classdev *led_cdev);
404 static inline void led_set_trigger_data(struct led_classdev *led_cdev,
407 led_cdev->trigger_data = trigger_data;
410 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
412 return led_cdev->trigger_data;
416 * led_trigger_rename_static - rename a trigger
417 * @name: the new trigger name
418 * @trig: the LED trigger to rename
420 * Change a LED trigger name by copying the string passed in
421 * name into current trigger name, which MUST be large
422 * enough for the new string.
424 * Note that name must NOT point to the same string used
425 * during LED registration, as that could lead to races.
427 * This is meant to be used on triggers with statically
430 void led_trigger_rename_static(const char *name, struct led_trigger *trig);
432 #define module_led_trigger(__led_trigger) \
433 module_driver(__led_trigger, led_trigger_register, \
434 led_trigger_unregister)
438 /* Trigger has no members */
439 struct led_trigger {};
441 /* Trigger inline empty functions */
442 static inline void led_trigger_register_simple(const char *name,
443 struct led_trigger **trigger) {}
444 static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
445 static inline void led_trigger_event(struct led_trigger *trigger,
446 enum led_brightness event) {}
447 static inline void led_trigger_blink(struct led_trigger *trigger,
448 unsigned long *delay_on,
449 unsigned long *delay_off) {}
450 static inline void led_trigger_blink_oneshot(struct led_trigger *trigger,
451 unsigned long *delay_on,
452 unsigned long *delay_off,
454 static inline void led_trigger_set_default(struct led_classdev *led_cdev) {}
455 static inline int led_trigger_set(struct led_classdev *led_cdev,
456 struct led_trigger *trigger)
461 static inline void led_trigger_remove(struct led_classdev *led_cdev) {}
462 static inline void led_set_trigger_data(struct led_classdev *led_cdev) {}
463 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
468 #endif /* CONFIG_LEDS_TRIGGERS */
470 /* Trigger specific functions */
471 #ifdef CONFIG_LEDS_TRIGGER_DISK
472 void ledtrig_disk_activity(bool write);
474 static inline void ledtrig_disk_activity(bool write) {}
477 #ifdef CONFIG_LEDS_TRIGGER_MTD
478 void ledtrig_mtd_activity(void);
480 static inline void ledtrig_mtd_activity(void) {}
483 #if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
484 void ledtrig_flash_ctrl(bool on);
485 void ledtrig_torch_ctrl(bool on);
487 static inline void ledtrig_flash_ctrl(bool on) {}
488 static inline void ledtrig_torch_ctrl(bool on) {}
492 * Generic LED platform data for describing LED names and default triggers.
496 const char *default_trigger;
500 struct led_platform_data {
502 struct led_info *leds;
505 struct led_properties {
508 const char *function;
510 bool func_enum_present;
515 typedef int (*gpio_blink_set_t)(struct gpio_desc *desc, int state,
516 unsigned long *delay_on,
517 unsigned long *delay_off);
519 /* For the leds-gpio driver */
522 const char *default_trigger;
524 unsigned active_low : 1;
525 unsigned retain_state_suspended : 1;
526 unsigned panic_indicator : 1;
527 unsigned default_state : 2;
528 unsigned retain_state_shutdown : 1;
529 /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
530 struct gpio_desc *gpiod;
532 #define LEDS_GPIO_DEFSTATE_OFF LEDS_DEFSTATE_OFF
533 #define LEDS_GPIO_DEFSTATE_ON LEDS_DEFSTATE_ON
534 #define LEDS_GPIO_DEFSTATE_KEEP LEDS_DEFSTATE_KEEP
536 struct gpio_led_platform_data {
538 const struct gpio_led *leds;
540 #define GPIO_LED_NO_BLINK_LOW 0 /* No blink GPIO state low */
541 #define GPIO_LED_NO_BLINK_HIGH 1 /* No blink GPIO state high */
542 #define GPIO_LED_BLINK 2 /* Please, blink */
543 gpio_blink_set_t gpio_blink_set;
546 #ifdef CONFIG_NEW_LEDS
547 struct platform_device *gpio_led_register_device(
548 int id, const struct gpio_led_platform_data *pdata);
550 static inline struct platform_device *gpio_led_register_device(
551 int id, const struct gpio_led_platform_data *pdata)
558 CPU_LED_IDLE_START, /* CPU enters idle */
559 CPU_LED_IDLE_END, /* CPU idle ends */
560 CPU_LED_START, /* Machine starts, especially resume */
561 CPU_LED_STOP, /* Machine stops, especially suspend */
562 CPU_LED_HALTED, /* Machine shutdown */
564 #ifdef CONFIG_LEDS_TRIGGER_CPU
565 void ledtrig_cpu(enum cpu_led_event evt);
567 static inline void ledtrig_cpu(enum cpu_led_event evt)
573 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
574 void led_classdev_notify_brightness_hw_changed(
575 struct led_classdev *led_cdev, unsigned int brightness);
577 static inline void led_classdev_notify_brightness_hw_changed(
578 struct led_classdev *led_cdev, enum led_brightness brightness) { }
582 * struct led_pattern - pattern interval settings
583 * @delta_t: pattern interval delay, in milliseconds
584 * @brightness: pattern interval brightness
592 LED_AUDIO_MUTE, /* master mute LED */
593 LED_AUDIO_MICMUTE, /* mic mute LED */
597 #if IS_ENABLED(CONFIG_LEDS_TRIGGER_AUDIO)
598 enum led_brightness ledtrig_audio_get(enum led_audio type);
599 void ledtrig_audio_set(enum led_audio type, enum led_brightness state);
601 static inline enum led_brightness ledtrig_audio_get(enum led_audio type)
605 static inline void ledtrig_audio_set(enum led_audio type,
606 enum led_brightness state)
611 #endif /* __LINUX_LEDS_H_INCLUDED */