1 /* SPDX-License-Identifier: GPL-2.0-only */
3 * Driver model for leds and led triggers
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/mutex.h>
14 #include <linux/rwsem.h>
15 #include <linux/spinlock.h>
16 #include <linux/timer.h>
17 #include <linux/types.h>
18 #include <linux/workqueue.h>
20 struct attribute_group;
26 struct platform_device;
32 /* This is obsolete/useless. We now support variable maximum brightness. */
40 enum led_default_state {
41 LEDS_DEFSTATE_OFF = 0,
43 LEDS_DEFSTATE_KEEP = 2,
47 * struct led_lookup_data - represents a single LED lookup entry
49 * @list: internal list of all LED lookup entries
50 * @provider: name of led_classdev providing the LED
51 * @dev_id: name of the device associated with this LED
52 * @con_id: name of the LED from the device's point of view
54 struct led_lookup_data {
55 struct list_head list;
61 struct led_init_data {
62 /* device fwnode handle */
63 struct fwnode_handle *fwnode;
65 * default <color:function> tuple, for backward compatibility
66 * with in-driver hard-coded LED names used as a fallback when
67 * DT "label" property is absent; it should be set to NULL
68 * in new LED class drivers.
70 const char *default_label;
72 * string to be used for devicename section of LED class device
73 * either for label based LED name composition path or for fwnode
74 * based when devname_mandatory is true
76 const char *devicename;
78 * indicates if LED name should always comprise devicename section;
79 * only LEDs exposed by drivers of hot-pluggable devices should
82 bool devname_mandatory;
85 enum led_default_state led_init_default_state_get(struct fwnode_handle *fwnode);
87 struct led_hw_trigger_type {
93 unsigned int brightness;
94 unsigned int max_brightness;
97 /* Lower 16 bits reflect status */
98 #define LED_SUSPENDED BIT(0)
99 #define LED_UNREGISTERING BIT(1)
100 /* Upper 16 bits reflect control information */
101 #define LED_CORE_SUSPENDRESUME BIT(16)
102 #define LED_SYSFS_DISABLE BIT(17)
103 #define LED_DEV_CAP_FLASH BIT(18)
104 #define LED_HW_PLUGGABLE BIT(19)
105 #define LED_PANIC_INDICATOR BIT(20)
106 #define LED_BRIGHT_HW_CHANGED BIT(21)
107 #define LED_RETAIN_AT_SHUTDOWN BIT(22)
108 #define LED_INIT_DEFAULT_TRIGGER BIT(23)
110 /* set_brightness_work / blink_timer flags, atomic, private. */
111 unsigned long work_flags;
113 #define LED_BLINK_SW 0
114 #define LED_BLINK_ONESHOT 1
115 #define LED_BLINK_ONESHOT_STOP 2
116 #define LED_BLINK_INVERT 3
117 #define LED_BLINK_BRIGHTNESS_CHANGE 4
118 #define LED_BLINK_DISABLE 5
120 /* Set LED brightness level
121 * Must not sleep. Use brightness_set_blocking for drivers
122 * that can sleep while setting brightness.
124 void (*brightness_set)(struct led_classdev *led_cdev,
125 enum led_brightness brightness);
127 * Set LED brightness level immediately - it can block the caller for
128 * the time required for accessing a LED device register.
130 int (*brightness_set_blocking)(struct led_classdev *led_cdev,
131 enum led_brightness brightness);
132 /* Get LED brightness level */
133 enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
136 * Activate hardware accelerated blink, delays are in milliseconds
137 * and if both are zero then a sensible default should be chosen.
138 * The call should adjust the timings in that case and if it can't
139 * match the values specified exactly.
140 * Deactivate blinking again when the brightness is set to LED_OFF
141 * via the brightness_set() callback.
143 int (*blink_set)(struct led_classdev *led_cdev,
144 unsigned long *delay_on,
145 unsigned long *delay_off);
147 int (*pattern_set)(struct led_classdev *led_cdev,
148 struct led_pattern *pattern, u32 len, int repeat);
149 int (*pattern_clear)(struct led_classdev *led_cdev);
152 const struct attribute_group **groups;
154 struct list_head node; /* LED Device list */
155 const char *default_trigger; /* Trigger to use */
157 unsigned long blink_delay_on, blink_delay_off;
158 struct timer_list blink_timer;
159 int blink_brightness;
160 int new_blink_brightness;
161 void (*flash_resume)(struct led_classdev *led_cdev);
163 struct work_struct set_brightness_work;
164 int delayed_set_value;
166 #ifdef CONFIG_LEDS_TRIGGERS
167 /* Protects the trigger data below */
168 struct rw_semaphore trigger_lock;
170 struct led_trigger *trigger;
171 struct list_head trig_list;
173 /* true if activated - deactivate routine uses it to do cleanup */
176 /* LEDs that have private triggers have this set */
177 struct led_hw_trigger_type *trigger_type;
180 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
181 int brightness_hw_changed;
182 struct kernfs_node *brightness_hw_changed_kn;
185 /* Ensures consistent access to the LED Flash Class device */
186 struct mutex led_access;
190 * led_classdev_register_ext - register a new object of LED class with
192 * @parent: LED controller device this LED is driven by
193 * @led_cdev: the led_classdev structure for this device
194 * @init_data: the LED class device initialization data
196 * Register a new object of LED class, with name derived from init_data.
198 * Returns: 0 on success or negative error value on failure
200 int led_classdev_register_ext(struct device *parent,
201 struct led_classdev *led_cdev,
202 struct led_init_data *init_data);
205 * led_classdev_register - register a new object of LED class
206 * @parent: LED controller device this LED is driven by
207 * @led_cdev: the led_classdev structure for this device
209 * Register a new object of LED class, with name derived from the name property
210 * of passed led_cdev argument.
212 * Returns: 0 on success or negative error value on failure
214 static inline int led_classdev_register(struct device *parent,
215 struct led_classdev *led_cdev)
217 return led_classdev_register_ext(parent, led_cdev, NULL);
220 int devm_led_classdev_register_ext(struct device *parent,
221 struct led_classdev *led_cdev,
222 struct led_init_data *init_data);
224 static inline int devm_led_classdev_register(struct device *parent,
225 struct led_classdev *led_cdev)
227 return devm_led_classdev_register_ext(parent, led_cdev, NULL);
229 void led_classdev_unregister(struct led_classdev *led_cdev);
230 void devm_led_classdev_unregister(struct device *parent,
231 struct led_classdev *led_cdev);
232 void led_classdev_suspend(struct led_classdev *led_cdev);
233 void led_classdev_resume(struct led_classdev *led_cdev);
235 void led_add_lookup(struct led_lookup_data *led_lookup);
236 void led_remove_lookup(struct led_lookup_data *led_lookup);
238 struct led_classdev *__must_check led_get(struct device *dev, char *con_id);
239 struct led_classdev *__must_check devm_led_get(struct device *dev, char *con_id);
241 extern struct led_classdev *of_led_get(struct device_node *np, int index);
242 extern void led_put(struct led_classdev *led_cdev);
243 struct led_classdev *__must_check devm_of_led_get(struct device *dev,
247 * led_blink_set - set blinking with software fallback
248 * @led_cdev: the LED to start blinking
249 * @delay_on: the time it should be on (in ms)
250 * @delay_off: the time it should ble off (in ms)
252 * This function makes the LED blink, attempting to use the
253 * hardware acceleration if possible, but falling back to
254 * software blinking if there is no hardware blinking or if
255 * the LED refuses the passed values.
257 * Note that if software blinking is active, simply calling
258 * led_cdev->brightness_set() will not stop the blinking,
259 * use led_classdev_brightness_set() instead.
261 void led_blink_set(struct led_classdev *led_cdev, unsigned long *delay_on,
262 unsigned long *delay_off);
264 * led_blink_set_oneshot - do a oneshot software blink
265 * @led_cdev: the LED to start blinking
266 * @delay_on: the time it should be on (in ms)
267 * @delay_off: the time it should ble off (in ms)
268 * @invert: blink off, then on, leaving the led on
270 * This function makes the LED blink one time for delay_on +
271 * delay_off time, ignoring the request if another one-shot
272 * blink is already in progress.
274 * If invert is set, led blinks for delay_off first, then for
275 * delay_on and leave the led on after the on-off cycle.
277 void led_blink_set_oneshot(struct led_classdev *led_cdev,
278 unsigned long *delay_on, unsigned long *delay_off,
281 * led_set_brightness - set LED brightness
282 * @led_cdev: the LED to set
283 * @brightness: the brightness to set it to
285 * Set an LED's brightness, and, if necessary, cancel the
286 * software blink timer that implements blinking when the
287 * hardware doesn't. This function is guaranteed not to sleep.
289 void led_set_brightness(struct led_classdev *led_cdev, unsigned int brightness);
292 * led_set_brightness_sync - set LED brightness synchronously
293 * @led_cdev: the LED to set
294 * @value: the brightness to set it to
296 * Set an LED's brightness immediately. This function will block
297 * the caller for the time required for accessing device registers,
300 * Returns: 0 on success or negative error value on failure
302 int led_set_brightness_sync(struct led_classdev *led_cdev, unsigned int value);
305 * led_update_brightness - update LED brightness
306 * @led_cdev: the LED to query
308 * Get an LED's current brightness and update led_cdev->brightness
309 * member with the obtained value.
311 * Returns: 0 on success or negative error value on failure
313 int led_update_brightness(struct led_classdev *led_cdev);
316 * led_get_default_pattern - return default pattern
318 * @led_cdev: the LED to get default pattern for
319 * @size: pointer for storing the number of elements in returned array,
320 * modified only if return != NULL
322 * Return: Allocated array of integers with default pattern from device tree
323 * or NULL. Caller is responsible for kfree().
325 u32 *led_get_default_pattern(struct led_classdev *led_cdev, unsigned int *size);
328 * led_sysfs_disable - disable LED sysfs interface
329 * @led_cdev: the LED to set
331 * Disable the led_cdev's sysfs interface.
333 void led_sysfs_disable(struct led_classdev *led_cdev);
336 * led_sysfs_enable - enable LED sysfs interface
337 * @led_cdev: the LED to set
339 * Enable the led_cdev's sysfs interface.
341 void led_sysfs_enable(struct led_classdev *led_cdev);
344 * led_compose_name - compose LED class device name
345 * @dev: LED controller device object
346 * @init_data: the LED class device initialization data
347 * @led_classdev_name: composed LED class device name
349 * Create LED class device name basing on the provided init_data argument.
350 * The name can have <devicename:color:function> or <color:function>.
351 * form, depending on the init_data configuration.
353 * Returns: 0 on success or negative error value on failure
355 int led_compose_name(struct device *dev, struct led_init_data *init_data,
356 char *led_classdev_name);
359 * led_sysfs_is_disabled - check if LED sysfs interface is disabled
360 * @led_cdev: the LED to query
362 * Returns: true if the led_cdev's sysfs interface is disabled.
364 static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
366 return led_cdev->flags & LED_SYSFS_DISABLE;
372 /* Registration functions for simple triggers */
373 #define DEFINE_LED_TRIGGER(x) static struct led_trigger *x;
374 #define DEFINE_LED_TRIGGER_GLOBAL(x) struct led_trigger *x;
376 #ifdef CONFIG_LEDS_TRIGGERS
378 #define TRIG_NAME_MAX 50
381 /* Trigger Properties */
383 int (*activate)(struct led_classdev *led_cdev);
384 void (*deactivate)(struct led_classdev *led_cdev);
386 /* LED-private triggers have this set */
387 struct led_hw_trigger_type *trigger_type;
389 /* LEDs under control by this trigger (for simple triggers) */
390 spinlock_t leddev_list_lock;
391 struct list_head led_cdevs;
393 /* Link to next registered trigger */
394 struct list_head next_trig;
396 const struct attribute_group **groups;
400 * Currently the attributes in struct led_trigger::groups are added directly to
401 * the LED device. As this might change in the future, the following
402 * macros abstract getting the LED device and its trigger_data from the dev
403 * parameter passed to the attribute accessor functions.
405 #define led_trigger_get_led(dev) ((struct led_classdev *)dev_get_drvdata((dev)))
406 #define led_trigger_get_drvdata(dev) (led_get_trigger_data(led_trigger_get_led(dev)))
408 /* Registration functions for complex triggers */
409 int led_trigger_register(struct led_trigger *trigger);
410 void led_trigger_unregister(struct led_trigger *trigger);
411 int devm_led_trigger_register(struct device *dev,
412 struct led_trigger *trigger);
414 void led_trigger_register_simple(const char *name,
415 struct led_trigger **trigger);
416 void led_trigger_unregister_simple(struct led_trigger *trigger);
417 void led_trigger_event(struct led_trigger *trigger, enum led_brightness event);
418 void led_trigger_blink(struct led_trigger *trigger, unsigned long *delay_on,
419 unsigned long *delay_off);
420 void led_trigger_blink_oneshot(struct led_trigger *trigger,
421 unsigned long *delay_on,
422 unsigned long *delay_off,
424 void led_trigger_set_default(struct led_classdev *led_cdev);
425 int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger);
426 void led_trigger_remove(struct led_classdev *led_cdev);
428 static inline void led_set_trigger_data(struct led_classdev *led_cdev,
431 led_cdev->trigger_data = trigger_data;
434 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
436 return led_cdev->trigger_data;
440 * led_trigger_rename_static - rename a trigger
441 * @name: the new trigger name
442 * @trig: the LED trigger to rename
444 * Change a LED trigger name by copying the string passed in
445 * name into current trigger name, which MUST be large
446 * enough for the new string.
448 * Note that name must NOT point to the same string used
449 * during LED registration, as that could lead to races.
451 * This is meant to be used on triggers with statically
454 void led_trigger_rename_static(const char *name, struct led_trigger *trig);
456 #define module_led_trigger(__led_trigger) \
457 module_driver(__led_trigger, led_trigger_register, \
458 led_trigger_unregister)
462 /* Trigger has no members */
463 struct led_trigger {};
465 /* Trigger inline empty functions */
466 static inline void led_trigger_register_simple(const char *name,
467 struct led_trigger **trigger) {}
468 static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
469 static inline void led_trigger_event(struct led_trigger *trigger,
470 enum led_brightness event) {}
471 static inline void led_trigger_blink(struct led_trigger *trigger,
472 unsigned long *delay_on,
473 unsigned long *delay_off) {}
474 static inline void led_trigger_blink_oneshot(struct led_trigger *trigger,
475 unsigned long *delay_on,
476 unsigned long *delay_off,
478 static inline void led_trigger_set_default(struct led_classdev *led_cdev) {}
479 static inline int led_trigger_set(struct led_classdev *led_cdev,
480 struct led_trigger *trigger)
485 static inline void led_trigger_remove(struct led_classdev *led_cdev) {}
486 static inline void led_set_trigger_data(struct led_classdev *led_cdev) {}
487 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
492 #endif /* CONFIG_LEDS_TRIGGERS */
494 /* Trigger specific functions */
495 #ifdef CONFIG_LEDS_TRIGGER_DISK
496 void ledtrig_disk_activity(bool write);
498 static inline void ledtrig_disk_activity(bool write) {}
501 #ifdef CONFIG_LEDS_TRIGGER_MTD
502 void ledtrig_mtd_activity(void);
504 static inline void ledtrig_mtd_activity(void) {}
507 #if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
508 void ledtrig_flash_ctrl(bool on);
509 void ledtrig_torch_ctrl(bool on);
511 static inline void ledtrig_flash_ctrl(bool on) {}
512 static inline void ledtrig_torch_ctrl(bool on) {}
516 * Generic LED platform data for describing LED names and default triggers.
520 const char *default_trigger;
524 struct led_platform_data {
526 struct led_info *leds;
529 struct led_properties {
532 const char *function;
534 bool func_enum_present;
538 typedef int (*gpio_blink_set_t)(struct gpio_desc *desc, int state,
539 unsigned long *delay_on,
540 unsigned long *delay_off);
542 /* For the leds-gpio driver */
545 const char *default_trigger;
547 unsigned active_low : 1;
548 unsigned retain_state_suspended : 1;
549 unsigned panic_indicator : 1;
550 unsigned default_state : 2;
551 unsigned retain_state_shutdown : 1;
552 /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
553 struct gpio_desc *gpiod;
555 #define LEDS_GPIO_DEFSTATE_OFF LEDS_DEFSTATE_OFF
556 #define LEDS_GPIO_DEFSTATE_ON LEDS_DEFSTATE_ON
557 #define LEDS_GPIO_DEFSTATE_KEEP LEDS_DEFSTATE_KEEP
559 struct gpio_led_platform_data {
561 const struct gpio_led *leds;
563 #define GPIO_LED_NO_BLINK_LOW 0 /* No blink GPIO state low */
564 #define GPIO_LED_NO_BLINK_HIGH 1 /* No blink GPIO state high */
565 #define GPIO_LED_BLINK 2 /* Please, blink */
566 gpio_blink_set_t gpio_blink_set;
569 #ifdef CONFIG_NEW_LEDS
570 struct platform_device *gpio_led_register_device(
571 int id, const struct gpio_led_platform_data *pdata);
573 static inline struct platform_device *gpio_led_register_device(
574 int id, const struct gpio_led_platform_data *pdata)
581 CPU_LED_IDLE_START, /* CPU enters idle */
582 CPU_LED_IDLE_END, /* CPU idle ends */
583 CPU_LED_START, /* Machine starts, especially resume */
584 CPU_LED_STOP, /* Machine stops, especially suspend */
585 CPU_LED_HALTED, /* Machine shutdown */
587 #ifdef CONFIG_LEDS_TRIGGER_CPU
588 void ledtrig_cpu(enum cpu_led_event evt);
590 static inline void ledtrig_cpu(enum cpu_led_event evt)
596 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
597 void led_classdev_notify_brightness_hw_changed(
598 struct led_classdev *led_cdev, unsigned int brightness);
600 static inline void led_classdev_notify_brightness_hw_changed(
601 struct led_classdev *led_cdev, enum led_brightness brightness) { }
605 * struct led_pattern - pattern interval settings
606 * @delta_t: pattern interval delay, in milliseconds
607 * @brightness: pattern interval brightness
615 LED_AUDIO_MUTE, /* master mute LED */
616 LED_AUDIO_MICMUTE, /* mic mute LED */
620 #if IS_ENABLED(CONFIG_LEDS_TRIGGER_AUDIO)
621 enum led_brightness ledtrig_audio_get(enum led_audio type);
622 void ledtrig_audio_set(enum led_audio type, enum led_brightness state);
624 static inline enum led_brightness ledtrig_audio_get(enum led_audio type)
628 static inline void ledtrig_audio_set(enum led_audio type,
629 enum led_brightness state)
634 #endif /* __LINUX_LEDS_H_INCLUDED */