1 /*
2 * Driver model for leds and led triggers
3 *
4 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
5 * Copyright (C) 2005 Richard Purdie <rpurdie@openedhand.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 */
12 #ifndef __LINUX_LEDS_H_INCLUDED
13 #define __LINUX_LEDS_H_INCLUDED
14
15 #include <linux/device.h>
16 #include <linux/kernfs.h>
17 #include <linux/list.h>
18 #include <linux/mutex.h>
19 #include <linux/rwsem.h>
20 #include <linux/spinlock.h>
21 #include <linux/timer.h>
22 #include <linux/workqueue.h>
23
24 struct device;
25 /*
26 * LED Core
27 */
28
29 enum led_brightness {
30 LED_OFF = 0,
31 LED_ON = 1,
32 LED_HALF = 127,
33 LED_FULL = 255,
34 };
35
36 struct led_classdev {
37 const char *name;
38 enum led_brightness brightness;
39 enum led_brightness max_brightness;
40 int flags;
41
42 /* Lower 16 bits reflect status */
43 #define LED_SUSPENDED BIT(0)
44 #define LED_UNREGISTERING BIT(1)
45 /* Upper 16 bits reflect control information */
46 #define LED_CORE_SUSPENDRESUME BIT(16)
47 #define LED_SYSFS_DISABLE BIT(17)
48 #define LED_DEV_CAP_FLASH BIT(18)
49 #define LED_HW_PLUGGABLE BIT(19)
50 #define LED_PANIC_INDICATOR BIT(20)
51 #define LED_BRIGHT_HW_CHANGED BIT(21)
52 #define LED_RETAIN_AT_SHUTDOWN BIT(22)
53
54 /* set_brightness_work / blink_timer flags, atomic, private. */
55 unsigned long work_flags;
56
57 #define LED_BLINK_SW 0
58 #define LED_BLINK_ONESHOT 1
59 #define LED_BLINK_ONESHOT_STOP 2
60 #define LED_BLINK_INVERT 3
61 #define LED_BLINK_BRIGHTNESS_CHANGE 4
62 #define LED_BLINK_DISABLE 5
63
64 /* Set LED brightness level
65 * Must not sleep. Use brightness_set_blocking for drivers
66 * that can sleep while setting brightness.
67 */
68 void (*brightness_set)(struct led_classdev *led_cdev,
69 enum led_brightness brightness);
70 /*
71 * Set LED brightness level immediately - it can block the caller for
72 * the time required for accessing a LED device register.
73 */
74 int (*brightness_set_blocking)(struct led_classdev *led_cdev,
75 enum led_brightness brightness);
76 /* Get LED brightness level */
77 enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
78
79 /*
80 * Activate hardware accelerated blink, delays are in milliseconds
81 * and if both are zero then a sensible default should be chosen.
82 * The call should adjust the timings in that case and if it can't
83 * match the values specified exactly.
84 * Deactivate blinking again when the brightness is set to LED_OFF
85 * via the brightness_set() callback.
86 */
87 int (*blink_set)(struct led_classdev *led_cdev,
88 unsigned long *delay_on,
89 unsigned long *delay_off);
90
91 struct device *dev;
92 const struct attribute_group **groups;
93
94 struct list_head node; /* LED Device list */
95 const char *default_trigger; /* Trigger to use */
96
97 unsigned long blink_delay_on, blink_delay_off;
98 struct timer_list blink_timer;
99 int blink_brightness;
100 int new_blink_brightness;
101 void (*flash_resume)(struct led_classdev *led_cdev);
102
103 struct work_struct set_brightness_work;
104 int delayed_set_value;
105
106 #ifdef CONFIG_LEDS_TRIGGERS
107 /* Protects the trigger data below */
108 struct rw_semaphore trigger_lock;
109
110 struct led_trigger *trigger;
111 struct list_head trig_list;
112 void *trigger_data;
113 /* true if activated - deactivate routine uses it to do cleanup */
114 bool activated;
115 #endif
116
117 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
118 int brightness_hw_changed;
119 struct kernfs_node *brightness_hw_changed_kn;
120 #endif
121
122 /* Ensures consistent access to the LED Flash Class device */
123 struct mutex led_access;
124 };
125
126 extern int of_led_classdev_register(struct device *parent,
127 struct device_node *np,
128 struct led_classdev *led_cdev);
129 #define led_classdev_register(parent, led_cdev) \
130 of_led_classdev_register(parent, NULL, led_cdev)
131 extern int devm_of_led_classdev_register(struct device *parent,
132 struct device_node *np,
133 struct led_classdev *led_cdev);
134 #define devm_led_classdev_register(parent, led_cdev) \
135 devm_of_led_classdev_register(parent, NULL, led_cdev)
136 extern void led_classdev_unregister(struct led_classdev *led_cdev);
137 extern void devm_led_classdev_unregister(struct device *parent,
138 struct led_classdev *led_cdev);
139 extern void led_classdev_suspend(struct led_classdev *led_cdev);
140 extern void led_classdev_resume(struct led_classdev *led_cdev);
141
142 /**
143 * led_blink_set - set blinking with software fallback
144 * @led_cdev: the LED to start blinking
145 * @delay_on: the time it should be on (in ms)
146 * @delay_off: the time it should ble off (in ms)
147 *
148 * This function makes the LED blink, attempting to use the
149 * hardware acceleration if possible, but falling back to
150 * software blinking if there is no hardware blinking or if
151 * the LED refuses the passed values.
152 *
153 * Note that if software blinking is active, simply calling
154 * led_cdev->brightness_set() will not stop the blinking,
155 * use led_classdev_brightness_set() instead.
156 */
157 extern void led_blink_set(struct led_classdev *led_cdev,
158 unsigned long *delay_on,
159 unsigned long *delay_off);
160 /**
161 * led_blink_set_oneshot - do a oneshot software blink
162 * @led_cdev: the LED to start blinking
163 * @delay_on: the time it should be on (in ms)
164 * @delay_off: the time it should ble off (in ms)
165 * @invert: blink off, then on, leaving the led on
166 *
167 * This function makes the LED blink one time for delay_on +
168 * delay_off time, ignoring the request if another one-shot
169 * blink is already in progress.
170 *
171 * If invert is set, led blinks for delay_off first, then for
172 * delay_on and leave the led on after the on-off cycle.
173 */
174 extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
175 unsigned long *delay_on,
176 unsigned long *delay_off,
177 int invert);
178 /**
179 * led_set_brightness - set LED brightness
180 * @led_cdev: the LED to set
181 * @brightness: the brightness to set it to
182 *
183 * Set an LED's brightness, and, if necessary, cancel the
184 * software blink timer that implements blinking when the
185 * hardware doesn't. This function is guaranteed not to sleep.
186 */
187 extern void led_set_brightness(struct led_classdev *led_cdev,
188 enum led_brightness brightness);
189
190 /**
191 * led_set_brightness_sync - set LED brightness synchronously
192 * @led_cdev: the LED to set
193 * @brightness: the brightness to set it to
194 *
195 * Set an LED's brightness immediately. This function will block
196 * the caller for the time required for accessing device registers,
197 * and it can sleep.
198 *
199 * Returns: 0 on success or negative error value on failure
200 */
201 extern int led_set_brightness_sync(struct led_classdev *led_cdev,
202 enum led_brightness value);
203
204 /**
205 * led_update_brightness - update LED brightness
206 * @led_cdev: the LED to query
207 *
208 * Get an LED's current brightness and update led_cdev->brightness
209 * member with the obtained value.
210 *
211 * Returns: 0 on success or negative error value on failure
212 */
213 extern int led_update_brightness(struct led_classdev *led_cdev);
214
215 /**
216 * led_sysfs_disable - disable LED sysfs interface
217 * @led_cdev: the LED to set
218 *
219 * Disable the led_cdev's sysfs interface.
220 */
221 extern void led_sysfs_disable(struct led_classdev *led_cdev);
222
223 /**
224 * led_sysfs_enable - enable LED sysfs interface
225 * @led_cdev: the LED to set
226 *
227 * Enable the led_cdev's sysfs interface.
228 */
229 extern void led_sysfs_enable(struct led_classdev *led_cdev);
230
231 /**
232 * led_sysfs_is_disabled - check if LED sysfs interface is disabled
233 * @led_cdev: the LED to query
234 *
235 * Returns: true if the led_cdev's sysfs interface is disabled.
236 */
led_sysfs_is_disabled(struct led_classdev * led_cdev)237 static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
238 {
239 return led_cdev->flags & LED_SYSFS_DISABLE;
240 }
241
242 /*
243 * LED Triggers
244 */
245 /* Registration functions for simple triggers */
246 #define DEFINE_LED_TRIGGER(x) static struct led_trigger *x;
247 #define DEFINE_LED_TRIGGER_GLOBAL(x) struct led_trigger *x;
248
249 #ifdef CONFIG_LEDS_TRIGGERS
250
251 #define TRIG_NAME_MAX 50
252
253 struct led_trigger {
254 /* Trigger Properties */
255 const char *name;
256 int (*activate)(struct led_classdev *led_cdev);
257 void (*deactivate)(struct led_classdev *led_cdev);
258
259 /* LEDs under control by this trigger (for simple triggers) */
260 rwlock_t leddev_list_lock;
261 struct list_head led_cdevs;
262
263 /* Link to next registered trigger */
264 struct list_head next_trig;
265
266 const struct attribute_group **groups;
267 };
268
269 /*
270 * Currently the attributes in struct led_trigger::groups are added directly to
271 * the LED device. As this might change in the future, the following
272 * macros abstract getting the LED device and its trigger_data from the dev
273 * parameter passed to the attribute accessor functions.
274 */
275 #define led_trigger_get_led(dev) ((struct led_classdev *)dev_get_drvdata((dev)))
276 #define led_trigger_get_drvdata(dev) (led_get_trigger_data(led_trigger_get_led(dev)))
277
278 ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
279 const char *buf, size_t count);
280 ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
281 char *buf);
282
283 /* Registration functions for complex triggers */
284 extern int led_trigger_register(struct led_trigger *trigger);
285 extern void led_trigger_unregister(struct led_trigger *trigger);
286 extern int devm_led_trigger_register(struct device *dev,
287 struct led_trigger *trigger);
288
289 extern void led_trigger_register_simple(const char *name,
290 struct led_trigger **trigger);
291 extern void led_trigger_unregister_simple(struct led_trigger *trigger);
292 extern void led_trigger_event(struct led_trigger *trigger,
293 enum led_brightness event);
294 extern void led_trigger_blink(struct led_trigger *trigger,
295 unsigned long *delay_on,
296 unsigned long *delay_off);
297 extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
298 unsigned long *delay_on,
299 unsigned long *delay_off,
300 int invert);
301 extern void led_trigger_set_default(struct led_classdev *led_cdev);
302 extern int led_trigger_set(struct led_classdev *led_cdev,
303 struct led_trigger *trigger);
304 extern void led_trigger_remove(struct led_classdev *led_cdev);
305
led_set_trigger_data(struct led_classdev * led_cdev,void * trigger_data)306 static inline void led_set_trigger_data(struct led_classdev *led_cdev,
307 void *trigger_data)
308 {
309 led_cdev->trigger_data = trigger_data;
310 }
311
led_get_trigger_data(struct led_classdev * led_cdev)312 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
313 {
314 return led_cdev->trigger_data;
315 }
316
317 /**
318 * led_trigger_rename_static - rename a trigger
319 * @name: the new trigger name
320 * @trig: the LED trigger to rename
321 *
322 * Change a LED trigger name by copying the string passed in
323 * name into current trigger name, which MUST be large
324 * enough for the new string.
325 *
326 * Note that name must NOT point to the same string used
327 * during LED registration, as that could lead to races.
328 *
329 * This is meant to be used on triggers with statically
330 * allocated name.
331 */
332 extern void led_trigger_rename_static(const char *name,
333 struct led_trigger *trig);
334
335 #define module_led_trigger(__led_trigger) \
336 module_driver(__led_trigger, led_trigger_register, \
337 led_trigger_unregister)
338
339 #else
340
341 /* Trigger has no members */
342 struct led_trigger {};
343
344 /* Trigger inline empty functions */
led_trigger_register_simple(const char * name,struct led_trigger ** trigger)345 static inline void led_trigger_register_simple(const char *name,
346 struct led_trigger **trigger) {}
led_trigger_unregister_simple(struct led_trigger * trigger)347 static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
led_trigger_event(struct led_trigger * trigger,enum led_brightness event)348 static inline void led_trigger_event(struct led_trigger *trigger,
349 enum led_brightness event) {}
led_trigger_blink(struct led_trigger * trigger,unsigned long * delay_on,unsigned long * delay_off)350 static inline void led_trigger_blink(struct led_trigger *trigger,
351 unsigned long *delay_on,
352 unsigned long *delay_off) {}
led_trigger_blink_oneshot(struct led_trigger * trigger,unsigned long * delay_on,unsigned long * delay_off,int invert)353 static inline void led_trigger_blink_oneshot(struct led_trigger *trigger,
354 unsigned long *delay_on,
355 unsigned long *delay_off,
356 int invert) {}
led_trigger_set_default(struct led_classdev * led_cdev)357 static inline void led_trigger_set_default(struct led_classdev *led_cdev) {}
led_trigger_set(struct led_classdev * led_cdev,struct led_trigger * trigger)358 static inline int led_trigger_set(struct led_classdev *led_cdev,
359 struct led_trigger *trigger)
360 {
361 return 0;
362 }
363
led_trigger_remove(struct led_classdev * led_cdev)364 static inline void led_trigger_remove(struct led_classdev *led_cdev) {}
led_set_trigger_data(struct led_classdev * led_cdev)365 static inline void led_set_trigger_data(struct led_classdev *led_cdev) {}
led_get_trigger_data(struct led_classdev * led_cdev)366 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
367 {
368 return NULL;
369 }
370
371 #endif /* CONFIG_LEDS_TRIGGERS */
372
373 /* Trigger specific functions */
374 #ifdef CONFIG_LEDS_TRIGGER_DISK
375 extern void ledtrig_disk_activity(bool write);
376 #else
ledtrig_disk_activity(bool write)377 static inline void ledtrig_disk_activity(bool write) {}
378 #endif
379
380 #ifdef CONFIG_LEDS_TRIGGER_MTD
381 extern void ledtrig_mtd_activity(void);
382 #else
ledtrig_mtd_activity(void)383 static inline void ledtrig_mtd_activity(void) {}
384 #endif
385
386 #if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
387 extern void ledtrig_flash_ctrl(bool on);
388 extern void ledtrig_torch_ctrl(bool on);
389 #else
ledtrig_flash_ctrl(bool on)390 static inline void ledtrig_flash_ctrl(bool on) {}
ledtrig_torch_ctrl(bool on)391 static inline void ledtrig_torch_ctrl(bool on) {}
392 #endif
393
394 /*
395 * Generic LED platform data for describing LED names and default triggers.
396 */
397 struct led_info {
398 const char *name;
399 const char *default_trigger;
400 int flags;
401 };
402
403 struct led_platform_data {
404 int num_leds;
405 struct led_info *leds;
406 };
407
408 struct gpio_desc;
409 typedef int (*gpio_blink_set_t)(struct gpio_desc *desc, int state,
410 unsigned long *delay_on,
411 unsigned long *delay_off);
412
413 /* For the leds-gpio driver */
414 struct gpio_led {
415 const char *name;
416 const char *default_trigger;
417 unsigned gpio;
418 unsigned active_low : 1;
419 unsigned retain_state_suspended : 1;
420 unsigned panic_indicator : 1;
421 unsigned default_state : 2;
422 unsigned retain_state_shutdown : 1;
423 /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
424 struct gpio_desc *gpiod;
425 };
426 #define LEDS_GPIO_DEFSTATE_OFF 0
427 #define LEDS_GPIO_DEFSTATE_ON 1
428 #define LEDS_GPIO_DEFSTATE_KEEP 2
429
430 struct gpio_led_platform_data {
431 int num_leds;
432 const struct gpio_led *leds;
433
434 #define GPIO_LED_NO_BLINK_LOW 0 /* No blink GPIO state low */
435 #define GPIO_LED_NO_BLINK_HIGH 1 /* No blink GPIO state high */
436 #define GPIO_LED_BLINK 2 /* Please, blink */
437 gpio_blink_set_t gpio_blink_set;
438 };
439
440 #ifdef CONFIG_NEW_LEDS
441 struct platform_device *gpio_led_register_device(
442 int id, const struct gpio_led_platform_data *pdata);
443 #else
gpio_led_register_device(int id,const struct gpio_led_platform_data * pdata)444 static inline struct platform_device *gpio_led_register_device(
445 int id, const struct gpio_led_platform_data *pdata)
446 {
447 return 0;
448 }
449 #endif
450
451 enum cpu_led_event {
452 CPU_LED_IDLE_START, /* CPU enters idle */
453 CPU_LED_IDLE_END, /* CPU idle ends */
454 CPU_LED_START, /* Machine starts, especially resume */
455 CPU_LED_STOP, /* Machine stops, especially suspend */
456 CPU_LED_HALTED, /* Machine shutdown */
457 };
458 #ifdef CONFIG_LEDS_TRIGGER_CPU
459 extern void ledtrig_cpu(enum cpu_led_event evt);
460 #else
ledtrig_cpu(enum cpu_led_event evt)461 static inline void ledtrig_cpu(enum cpu_led_event evt)
462 {
463 return;
464 }
465 #endif
466
467 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
468 extern void led_classdev_notify_brightness_hw_changed(
469 struct led_classdev *led_cdev, enum led_brightness brightness);
470 #else
led_classdev_notify_brightness_hw_changed(struct led_classdev * led_cdev,enum led_brightness brightness)471 static inline void led_classdev_notify_brightness_hw_changed(
472 struct led_classdev *led_cdev, enum led_brightness brightness) { }
473 #endif
474
475 #endif /* __LINUX_LEDS_H_INCLUDED */
476