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