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>
34 struct led_init_data {
35 /* device fwnode handle */
36 struct fwnode_handle *fwnode;
38 * default <color:function> tuple, for backward compatibility
39 * with in-driver hard-coded LED names used as a fallback when
40 * DT "label" property is absent; it should be set to NULL
41 * in new LED class drivers.
43 const char *default_label;
45 * string to be used for devicename section of LED class device
46 * either for label based LED name composition path or for fwnode
47 * based when devname_mandatory is true
49 const char *devicename;
51 * indicates if LED name should always comprise devicename section;
52 * only LEDs exposed by drivers of hot-pluggable devices should
55 bool devname_mandatory;
60 enum led_brightness brightness;
61 enum led_brightness max_brightness;
64 /* Lower 16 bits reflect status */
65 #define LED_SUSPENDED BIT(0)
66 #define LED_UNREGISTERING BIT(1)
67 /* Upper 16 bits reflect control information */
68 #define LED_CORE_SUSPENDRESUME BIT(16)
69 #define LED_SYSFS_DISABLE BIT(17)
70 #define LED_DEV_CAP_FLASH BIT(18)
71 #define LED_HW_PLUGGABLE BIT(19)
72 #define LED_PANIC_INDICATOR BIT(20)
73 #define LED_BRIGHT_HW_CHANGED BIT(21)
74 #define LED_RETAIN_AT_SHUTDOWN BIT(22)
75 #define LED_INIT_DEFAULT_TRIGGER BIT(23)
77 /* set_brightness_work / blink_timer flags, atomic, private. */
78 unsigned long work_flags;
80 #define LED_BLINK_SW 0
81 #define LED_BLINK_ONESHOT 1
82 #define LED_BLINK_ONESHOT_STOP 2
83 #define LED_BLINK_INVERT 3
84 #define LED_BLINK_BRIGHTNESS_CHANGE 4
85 #define LED_BLINK_DISABLE 5
87 /* Set LED brightness level
88 * Must not sleep. Use brightness_set_blocking for drivers
89 * that can sleep while setting brightness.
91 void (*brightness_set)(struct led_classdev *led_cdev,
92 enum led_brightness brightness);
94 * Set LED brightness level immediately - it can block the caller for
95 * the time required for accessing a LED device register.
97 int (*brightness_set_blocking)(struct led_classdev *led_cdev,
98 enum led_brightness brightness);
99 /* Get LED brightness level */
100 enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
103 * Activate hardware accelerated blink, delays are in milliseconds
104 * and if both are zero then a sensible default should be chosen.
105 * The call should adjust the timings in that case and if it can't
106 * match the values specified exactly.
107 * Deactivate blinking again when the brightness is set to LED_OFF
108 * via the brightness_set() callback.
110 int (*blink_set)(struct led_classdev *led_cdev,
111 unsigned long *delay_on,
112 unsigned long *delay_off);
114 int (*pattern_set)(struct led_classdev *led_cdev,
115 struct led_pattern *pattern, u32 len, int repeat);
116 int (*pattern_clear)(struct led_classdev *led_cdev);
119 const struct attribute_group **groups;
121 struct list_head node; /* LED Device list */
122 const char *default_trigger; /* Trigger to use */
124 unsigned long blink_delay_on, blink_delay_off;
125 struct timer_list blink_timer;
126 int blink_brightness;
127 int new_blink_brightness;
128 void (*flash_resume)(struct led_classdev *led_cdev);
130 struct work_struct set_brightness_work;
131 int delayed_set_value;
133 #ifdef CONFIG_LEDS_TRIGGERS
134 /* Protects the trigger data below */
135 struct rw_semaphore trigger_lock;
137 struct led_trigger *trigger;
138 struct list_head trig_list;
140 /* true if activated - deactivate routine uses it to do cleanup */
144 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
145 int brightness_hw_changed;
146 struct kernfs_node *brightness_hw_changed_kn;
149 /* Ensures consistent access to the LED Flash Class device */
150 struct mutex led_access;
154 * led_classdev_register_ext - register a new object of LED class with
156 * @parent: LED controller device this LED is driven by
157 * @led_cdev: the led_classdev structure for this device
158 * @init_data: the LED class device initialization data
160 * Register a new object of LED class, with name derived from init_data.
162 * Returns: 0 on success or negative error value on failure
164 extern int led_classdev_register_ext(struct device *parent,
165 struct led_classdev *led_cdev,
166 struct led_init_data *init_data);
169 * led_classdev_register - register a new object of LED class
170 * @parent: LED controller device this LED is driven by
171 * @led_cdev: the led_classdev structure for this device
173 * Register a new object of LED class, with name derived from the name property
174 * of passed led_cdev argument.
176 * Returns: 0 on success or negative error value on failure
178 static inline int led_classdev_register(struct device *parent,
179 struct led_classdev *led_cdev)
181 return led_classdev_register_ext(parent, led_cdev, NULL);
184 extern int devm_led_classdev_register_ext(struct device *parent,
185 struct led_classdev *led_cdev,
186 struct led_init_data *init_data);
188 static inline int devm_led_classdev_register(struct device *parent,
189 struct led_classdev *led_cdev)
191 return devm_led_classdev_register_ext(parent, led_cdev, NULL);
193 extern void led_classdev_unregister(struct led_classdev *led_cdev);
194 extern void devm_led_classdev_unregister(struct device *parent,
195 struct led_classdev *led_cdev);
196 extern void led_classdev_suspend(struct led_classdev *led_cdev);
197 extern void led_classdev_resume(struct led_classdev *led_cdev);
200 * led_blink_set - set blinking with software fallback
201 * @led_cdev: the LED to start blinking
202 * @delay_on: the time it should be on (in ms)
203 * @delay_off: the time it should ble off (in ms)
205 * This function makes the LED blink, attempting to use the
206 * hardware acceleration if possible, but falling back to
207 * software blinking if there is no hardware blinking or if
208 * the LED refuses the passed values.
210 * Note that if software blinking is active, simply calling
211 * led_cdev->brightness_set() will not stop the blinking,
212 * use led_classdev_brightness_set() instead.
214 extern void led_blink_set(struct led_classdev *led_cdev,
215 unsigned long *delay_on,
216 unsigned long *delay_off);
218 * led_blink_set_oneshot - do a oneshot software blink
219 * @led_cdev: the LED to start blinking
220 * @delay_on: the time it should be on (in ms)
221 * @delay_off: the time it should ble off (in ms)
222 * @invert: blink off, then on, leaving the led on
224 * This function makes the LED blink one time for delay_on +
225 * delay_off time, ignoring the request if another one-shot
226 * blink is already in progress.
228 * If invert is set, led blinks for delay_off first, then for
229 * delay_on and leave the led on after the on-off cycle.
231 extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
232 unsigned long *delay_on,
233 unsigned long *delay_off,
236 * led_set_brightness - set LED brightness
237 * @led_cdev: the LED to set
238 * @brightness: the brightness to set it to
240 * Set an LED's brightness, and, if necessary, cancel the
241 * software blink timer that implements blinking when the
242 * hardware doesn't. This function is guaranteed not to sleep.
244 extern void led_set_brightness(struct led_classdev *led_cdev,
245 enum led_brightness brightness);
248 * led_set_brightness_sync - set LED brightness synchronously
249 * @led_cdev: the LED to set
250 * @brightness: the brightness to set it to
252 * Set an LED's brightness immediately. This function will block
253 * the caller for the time required for accessing device registers,
256 * Returns: 0 on success or negative error value on failure
258 extern int led_set_brightness_sync(struct led_classdev *led_cdev,
259 enum led_brightness value);
262 * led_update_brightness - update LED brightness
263 * @led_cdev: the LED to query
265 * Get an LED's current brightness and update led_cdev->brightness
266 * member with the obtained value.
268 * Returns: 0 on success or negative error value on failure
270 extern int led_update_brightness(struct led_classdev *led_cdev);
273 * led_get_default_pattern - return default pattern
275 * @led_cdev: the LED to get default pattern for
276 * @size: pointer for storing the number of elements in returned array,
277 * modified only if return != NULL
279 * Return: Allocated array of integers with default pattern from device tree
280 * or NULL. Caller is responsible for kfree().
282 extern u32 *led_get_default_pattern(struct led_classdev *led_cdev,
286 * led_sysfs_disable - disable LED sysfs interface
287 * @led_cdev: the LED to set
289 * Disable the led_cdev's sysfs interface.
291 extern void led_sysfs_disable(struct led_classdev *led_cdev);
294 * led_sysfs_enable - enable LED sysfs interface
295 * @led_cdev: the LED to set
297 * Enable the led_cdev's sysfs interface.
299 extern void led_sysfs_enable(struct led_classdev *led_cdev);
302 * led_compose_name - compose LED class device name
303 * @dev: LED controller device object
304 * @child: child fwnode_handle describing a LED or a group of synchronized LEDs;
305 * it must be provided only for fwnode based LEDs
306 * @led_classdev_name: composed LED class device name
308 * Create LED class device name basing on the provided init_data argument.
309 * The name can have <devicename:color:function> or <color:function>.
310 * form, depending on the init_data configuration.
312 * Returns: 0 on success or negative error value on failure
314 extern int led_compose_name(struct device *dev, struct led_init_data *init_data,
315 char *led_classdev_name);
318 * led_sysfs_is_disabled - check if LED sysfs interface is disabled
319 * @led_cdev: the LED to query
321 * Returns: true if the led_cdev's sysfs interface is disabled.
323 static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
325 return led_cdev->flags & LED_SYSFS_DISABLE;
331 /* Registration functions for simple triggers */
332 #define DEFINE_LED_TRIGGER(x) static struct led_trigger *x;
333 #define DEFINE_LED_TRIGGER_GLOBAL(x) struct led_trigger *x;
335 #ifdef CONFIG_LEDS_TRIGGERS
337 #define TRIG_NAME_MAX 50
340 /* Trigger Properties */
342 int (*activate)(struct led_classdev *led_cdev);
343 void (*deactivate)(struct led_classdev *led_cdev);
345 /* LEDs under control by this trigger (for simple triggers) */
346 rwlock_t leddev_list_lock;
347 struct list_head led_cdevs;
349 /* Link to next registered trigger */
350 struct list_head next_trig;
352 const struct attribute_group **groups;
356 * Currently the attributes in struct led_trigger::groups are added directly to
357 * the LED device. As this might change in the future, the following
358 * macros abstract getting the LED device and its trigger_data from the dev
359 * parameter passed to the attribute accessor functions.
361 #define led_trigger_get_led(dev) ((struct led_classdev *)dev_get_drvdata((dev)))
362 #define led_trigger_get_drvdata(dev) (led_get_trigger_data(led_trigger_get_led(dev)))
364 ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
365 const char *buf, size_t count);
366 ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
369 /* Registration functions for complex triggers */
370 extern int led_trigger_register(struct led_trigger *trigger);
371 extern void led_trigger_unregister(struct led_trigger *trigger);
372 extern int devm_led_trigger_register(struct device *dev,
373 struct led_trigger *trigger);
375 extern void led_trigger_register_simple(const char *name,
376 struct led_trigger **trigger);
377 extern void led_trigger_unregister_simple(struct led_trigger *trigger);
378 extern void led_trigger_event(struct led_trigger *trigger,
379 enum led_brightness event);
380 extern void led_trigger_blink(struct led_trigger *trigger,
381 unsigned long *delay_on,
382 unsigned long *delay_off);
383 extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
384 unsigned long *delay_on,
385 unsigned long *delay_off,
387 extern void led_trigger_set_default(struct led_classdev *led_cdev);
388 extern int led_trigger_set(struct led_classdev *led_cdev,
389 struct led_trigger *trigger);
390 extern void led_trigger_remove(struct led_classdev *led_cdev);
392 static inline void led_set_trigger_data(struct led_classdev *led_cdev,
395 led_cdev->trigger_data = trigger_data;
398 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
400 return led_cdev->trigger_data;
404 * led_trigger_rename_static - rename a trigger
405 * @name: the new trigger name
406 * @trig: the LED trigger to rename
408 * Change a LED trigger name by copying the string passed in
409 * name into current trigger name, which MUST be large
410 * enough for the new string.
412 * Note that name must NOT point to the same string used
413 * during LED registration, as that could lead to races.
415 * This is meant to be used on triggers with statically
418 extern void led_trigger_rename_static(const char *name,
419 struct led_trigger *trig);
421 #define module_led_trigger(__led_trigger) \
422 module_driver(__led_trigger, led_trigger_register, \
423 led_trigger_unregister)
427 /* Trigger has no members */
428 struct led_trigger {};
430 /* Trigger inline empty functions */
431 static inline void led_trigger_register_simple(const char *name,
432 struct led_trigger **trigger) {}
433 static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
434 static inline void led_trigger_event(struct led_trigger *trigger,
435 enum led_brightness event) {}
436 static inline void led_trigger_blink(struct led_trigger *trigger,
437 unsigned long *delay_on,
438 unsigned long *delay_off) {}
439 static inline void led_trigger_blink_oneshot(struct led_trigger *trigger,
440 unsigned long *delay_on,
441 unsigned long *delay_off,
443 static inline void led_trigger_set_default(struct led_classdev *led_cdev) {}
444 static inline int led_trigger_set(struct led_classdev *led_cdev,
445 struct led_trigger *trigger)
450 static inline void led_trigger_remove(struct led_classdev *led_cdev) {}
451 static inline void led_set_trigger_data(struct led_classdev *led_cdev) {}
452 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
457 #endif /* CONFIG_LEDS_TRIGGERS */
459 /* Trigger specific functions */
460 #ifdef CONFIG_LEDS_TRIGGER_DISK
461 extern void ledtrig_disk_activity(bool write);
463 static inline void ledtrig_disk_activity(bool write) {}
466 #ifdef CONFIG_LEDS_TRIGGER_MTD
467 extern void ledtrig_mtd_activity(void);
469 static inline void ledtrig_mtd_activity(void) {}
472 #if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
473 extern void ledtrig_flash_ctrl(bool on);
474 extern void ledtrig_torch_ctrl(bool on);
476 static inline void ledtrig_flash_ctrl(bool on) {}
477 static inline void ledtrig_torch_ctrl(bool on) {}
481 * Generic LED platform data for describing LED names and default triggers.
485 const char *default_trigger;
489 struct led_platform_data {
491 struct led_info *leds;
494 struct led_properties {
497 const char *function;
499 bool func_enum_present;
504 typedef int (*gpio_blink_set_t)(struct gpio_desc *desc, int state,
505 unsigned long *delay_on,
506 unsigned long *delay_off);
508 /* For the leds-gpio driver */
511 const char *default_trigger;
513 unsigned active_low : 1;
514 unsigned retain_state_suspended : 1;
515 unsigned panic_indicator : 1;
516 unsigned default_state : 2;
517 unsigned retain_state_shutdown : 1;
518 /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
519 struct gpio_desc *gpiod;
521 #define LEDS_GPIO_DEFSTATE_OFF 0
522 #define LEDS_GPIO_DEFSTATE_ON 1
523 #define LEDS_GPIO_DEFSTATE_KEEP 2
525 struct gpio_led_platform_data {
527 const struct gpio_led *leds;
529 #define GPIO_LED_NO_BLINK_LOW 0 /* No blink GPIO state low */
530 #define GPIO_LED_NO_BLINK_HIGH 1 /* No blink GPIO state high */
531 #define GPIO_LED_BLINK 2 /* Please, blink */
532 gpio_blink_set_t gpio_blink_set;
535 #ifdef CONFIG_NEW_LEDS
536 struct platform_device *gpio_led_register_device(
537 int id, const struct gpio_led_platform_data *pdata);
539 static inline struct platform_device *gpio_led_register_device(
540 int id, const struct gpio_led_platform_data *pdata)
547 CPU_LED_IDLE_START, /* CPU enters idle */
548 CPU_LED_IDLE_END, /* CPU idle ends */
549 CPU_LED_START, /* Machine starts, especially resume */
550 CPU_LED_STOP, /* Machine stops, especially suspend */
551 CPU_LED_HALTED, /* Machine shutdown */
553 #ifdef CONFIG_LEDS_TRIGGER_CPU
554 extern void ledtrig_cpu(enum cpu_led_event evt);
556 static inline void ledtrig_cpu(enum cpu_led_event evt)
562 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
563 extern void led_classdev_notify_brightness_hw_changed(
564 struct led_classdev *led_cdev, enum led_brightness brightness);
566 static inline void led_classdev_notify_brightness_hw_changed(
567 struct led_classdev *led_cdev, enum led_brightness brightness) { }
571 * struct led_pattern - pattern interval settings
572 * @delta_t: pattern interval delay, in milliseconds
573 * @brightness: pattern interval brightness
581 LED_AUDIO_MUTE, /* master mute LED */
582 LED_AUDIO_MICMUTE, /* mic mute LED */
586 #if IS_ENABLED(CONFIG_LEDS_TRIGGER_AUDIO)
587 enum led_brightness ledtrig_audio_get(enum led_audio type);
588 void ledtrig_audio_set(enum led_audio type, enum led_brightness state);
590 static inline enum led_brightness ledtrig_audio_get(enum led_audio type)
594 static inline void ledtrig_audio_set(enum led_audio type,
595 enum led_brightness state)
600 #endif /* __LINUX_LEDS_H_INCLUDED */