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