Linux kernel mirror (for testing)
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linux
1/* drivers/rtc/alarm-dev.c
2 *
3 * Copyright (C) 2007-2009 Google, Inc.
4 *
5 * This software is licensed under the terms of the GNU General Public
6 * License version 2, as published by the Free Software Foundation, and
7 * may be copied, distributed, and modified under those terms.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 */
15
16#include <linux/time.h>
17#include <linux/module.h>
18#include <linux/device.h>
19#include <linux/miscdevice.h>
20#include <linux/fs.h>
21#include <linux/platform_device.h>
22#include <linux/sched.h>
23#include <linux/spinlock.h>
24#include <linux/uaccess.h>
25#include <linux/alarmtimer.h>
26#include "android_alarm.h"
27
28#define ANDROID_ALARM_PRINT_INFO (1U << 0)
29#define ANDROID_ALARM_PRINT_IO (1U << 1)
30#define ANDROID_ALARM_PRINT_INT (1U << 2)
31
32static int debug_mask = ANDROID_ALARM_PRINT_INFO;
33module_param_named(debug_mask, debug_mask, int, S_IRUGO | S_IWUSR | S_IWGRP);
34
35#define alarm_dbg(debug_level_mask, fmt, ...) \
36do { \
37 if (debug_mask & ANDROID_ALARM_PRINT_##debug_level_mask) \
38 pr_info(fmt, ##__VA_ARGS__); \
39} while (0)
40
41#define ANDROID_ALARM_WAKEUP_MASK ( \
42 ANDROID_ALARM_RTC_WAKEUP_MASK | \
43 ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP_MASK)
44
45static int alarm_opened;
46static DEFINE_SPINLOCK(alarm_slock);
47static struct wakeup_source alarm_wake_lock;
48static DECLARE_WAIT_QUEUE_HEAD(alarm_wait_queue);
49static uint32_t alarm_pending;
50static uint32_t alarm_enabled;
51static uint32_t wait_pending;
52
53struct devalarm {
54 union {
55 struct hrtimer hrt;
56 struct alarm alrm;
57 } u;
58 enum android_alarm_type type;
59};
60
61static struct devalarm alarms[ANDROID_ALARM_TYPE_COUNT];
62
63/**
64 * is_wakeup() - Checks to see if this alarm can wake the device
65 * @type: The type of alarm being checked
66 *
67 * Return: 1 if this is a wakeup alarm, otherwise 0
68 */
69static int is_wakeup(enum android_alarm_type type)
70{
71 return (type == ANDROID_ALARM_RTC_WAKEUP ||
72 type == ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP);
73}
74
75
76static void devalarm_start(struct devalarm *alrm, ktime_t exp)
77{
78 if (is_wakeup(alrm->type))
79 alarm_start(&alrm->u.alrm, exp);
80 else
81 hrtimer_start(&alrm->u.hrt, exp, HRTIMER_MODE_ABS);
82}
83
84static int devalarm_try_to_cancel(struct devalarm *alrm)
85{
86 if (is_wakeup(alrm->type))
87 return alarm_try_to_cancel(&alrm->u.alrm);
88 return hrtimer_try_to_cancel(&alrm->u.hrt);
89}
90
91static void devalarm_cancel(struct devalarm *alrm)
92{
93 if (is_wakeup(alrm->type))
94 alarm_cancel(&alrm->u.alrm);
95 else
96 hrtimer_cancel(&alrm->u.hrt);
97}
98
99static void alarm_clear(enum android_alarm_type alarm_type)
100{
101 uint32_t alarm_type_mask = 1U << alarm_type;
102 unsigned long flags;
103
104 spin_lock_irqsave(&alarm_slock, flags);
105 alarm_dbg(IO, "alarm %d clear\n", alarm_type);
106 devalarm_try_to_cancel(&alarms[alarm_type]);
107 if (alarm_pending) {
108 alarm_pending &= ~alarm_type_mask;
109 if (!alarm_pending && !wait_pending)
110 __pm_relax(&alarm_wake_lock);
111 }
112 alarm_enabled &= ~alarm_type_mask;
113 spin_unlock_irqrestore(&alarm_slock, flags);
114
115}
116
117static void alarm_set(enum android_alarm_type alarm_type,
118 struct timespec *ts)
119{
120 uint32_t alarm_type_mask = 1U << alarm_type;
121 unsigned long flags;
122
123 spin_lock_irqsave(&alarm_slock, flags);
124 alarm_dbg(IO, "alarm %d set %ld.%09ld\n",
125 alarm_type, ts->tv_sec, ts->tv_nsec);
126 alarm_enabled |= alarm_type_mask;
127 devalarm_start(&alarms[alarm_type], timespec_to_ktime(*ts));
128 spin_unlock_irqrestore(&alarm_slock, flags);
129}
130
131static int alarm_wait(void)
132{
133 unsigned long flags;
134 int rv = 0;
135
136 spin_lock_irqsave(&alarm_slock, flags);
137 alarm_dbg(IO, "alarm wait\n");
138 if (!alarm_pending && wait_pending) {
139 __pm_relax(&alarm_wake_lock);
140 wait_pending = 0;
141 }
142 spin_unlock_irqrestore(&alarm_slock, flags);
143
144 rv = wait_event_interruptible(alarm_wait_queue, alarm_pending);
145 if (rv)
146 return rv;
147
148 spin_lock_irqsave(&alarm_slock, flags);
149 rv = alarm_pending;
150 wait_pending = 1;
151 alarm_pending = 0;
152 spin_unlock_irqrestore(&alarm_slock, flags);
153
154 return rv;
155}
156
157static int alarm_set_rtc(struct timespec *ts)
158{
159 struct rtc_time new_rtc_tm;
160 struct rtc_device *rtc_dev;
161 unsigned long flags;
162 int rv = 0;
163
164 rtc_time_to_tm(ts->tv_sec, &new_rtc_tm);
165 rtc_dev = alarmtimer_get_rtcdev();
166 rv = do_settimeofday(ts);
167 if (rv < 0)
168 return rv;
169 if (rtc_dev)
170 rv = rtc_set_time(rtc_dev, &new_rtc_tm);
171
172 spin_lock_irqsave(&alarm_slock, flags);
173 alarm_pending |= ANDROID_ALARM_TIME_CHANGE_MASK;
174 wake_up(&alarm_wait_queue);
175 spin_unlock_irqrestore(&alarm_slock, flags);
176
177 return rv;
178}
179
180static int alarm_get_time(enum android_alarm_type alarm_type,
181 struct timespec *ts)
182{
183 int rv = 0;
184
185 switch (alarm_type) {
186 case ANDROID_ALARM_RTC_WAKEUP:
187 case ANDROID_ALARM_RTC:
188 getnstimeofday(ts);
189 break;
190 case ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP:
191 case ANDROID_ALARM_ELAPSED_REALTIME:
192 get_monotonic_boottime(ts);
193 break;
194 case ANDROID_ALARM_SYSTEMTIME:
195 ktime_get_ts(ts);
196 break;
197 default:
198 rv = -EINVAL;
199 }
200 return rv;
201}
202
203static long alarm_do_ioctl(struct file *file, unsigned int cmd,
204 struct timespec *ts)
205{
206 int rv = 0;
207 unsigned long flags;
208 enum android_alarm_type alarm_type = ANDROID_ALARM_IOCTL_TO_TYPE(cmd);
209
210 if (alarm_type >= ANDROID_ALARM_TYPE_COUNT)
211 return -EINVAL;
212
213 if (ANDROID_ALARM_BASE_CMD(cmd) != ANDROID_ALARM_GET_TIME(0)) {
214 if ((file->f_flags & O_ACCMODE) == O_RDONLY)
215 return -EPERM;
216 if (file->private_data == NULL &&
217 cmd != ANDROID_ALARM_SET_RTC) {
218 spin_lock_irqsave(&alarm_slock, flags);
219 if (alarm_opened) {
220 spin_unlock_irqrestore(&alarm_slock, flags);
221 return -EBUSY;
222 }
223 alarm_opened = 1;
224 file->private_data = (void *)1;
225 spin_unlock_irqrestore(&alarm_slock, flags);
226 }
227 }
228
229 switch (ANDROID_ALARM_BASE_CMD(cmd)) {
230 case ANDROID_ALARM_CLEAR(0):
231 alarm_clear(alarm_type);
232 break;
233 case ANDROID_ALARM_SET(0):
234 alarm_set(alarm_type, ts);
235 break;
236 case ANDROID_ALARM_SET_AND_WAIT(0):
237 alarm_set(alarm_type, ts);
238 /* fall though */
239 case ANDROID_ALARM_WAIT:
240 rv = alarm_wait();
241 break;
242 case ANDROID_ALARM_SET_RTC:
243 rv = alarm_set_rtc(ts);
244 break;
245 case ANDROID_ALARM_GET_TIME(0):
246 rv = alarm_get_time(alarm_type, ts);
247 break;
248
249 default:
250 rv = -EINVAL;
251 }
252 return rv;
253}
254
255static long alarm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
256{
257
258 struct timespec ts;
259 int rv;
260
261 switch (ANDROID_ALARM_BASE_CMD(cmd)) {
262 case ANDROID_ALARM_SET_AND_WAIT(0):
263 case ANDROID_ALARM_SET(0):
264 case ANDROID_ALARM_SET_RTC:
265 if (copy_from_user(&ts, (void __user *)arg, sizeof(ts)))
266 return -EFAULT;
267 break;
268 }
269
270 rv = alarm_do_ioctl(file, cmd, &ts);
271 if (rv)
272 return rv;
273
274 switch (ANDROID_ALARM_BASE_CMD(cmd)) {
275 case ANDROID_ALARM_GET_TIME(0):
276 if (copy_to_user((void __user *)arg, &ts, sizeof(ts)))
277 return -EFAULT;
278 break;
279 }
280
281 return 0;
282}
283#ifdef CONFIG_COMPAT
284static long alarm_compat_ioctl(struct file *file, unsigned int cmd,
285 unsigned long arg)
286{
287
288 struct timespec ts;
289 int rv;
290
291 switch (ANDROID_ALARM_BASE_CMD(cmd)) {
292 case ANDROID_ALARM_SET_AND_WAIT_COMPAT(0):
293 case ANDROID_ALARM_SET_COMPAT(0):
294 case ANDROID_ALARM_SET_RTC_COMPAT:
295 if (compat_get_timespec(&ts, (void __user *)arg))
296 return -EFAULT;
297 /* fall through */
298 case ANDROID_ALARM_GET_TIME_COMPAT(0):
299 cmd = ANDROID_ALARM_COMPAT_TO_NORM(cmd);
300 break;
301 }
302
303 rv = alarm_do_ioctl(file, cmd, &ts);
304 if (rv)
305 return rv;
306
307 switch (ANDROID_ALARM_BASE_CMD(cmd)) {
308 case ANDROID_ALARM_GET_TIME(0): /* NOTE: we modified cmd above */
309 if (compat_put_timespec(&ts, (void __user *)arg))
310 return -EFAULT;
311 break;
312 }
313
314 return 0;
315}
316#endif
317
318static int alarm_open(struct inode *inode, struct file *file)
319{
320 file->private_data = NULL;
321 return 0;
322}
323
324static int alarm_release(struct inode *inode, struct file *file)
325{
326 int i;
327 unsigned long flags;
328
329 spin_lock_irqsave(&alarm_slock, flags);
330 if (file->private_data) {
331 for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++) {
332 uint32_t alarm_type_mask = 1U << i;
333 if (alarm_enabled & alarm_type_mask) {
334 alarm_dbg(INFO,
335 "%s: clear alarm, pending %d\n",
336 __func__,
337 !!(alarm_pending & alarm_type_mask));
338 alarm_enabled &= ~alarm_type_mask;
339 }
340 spin_unlock_irqrestore(&alarm_slock, flags);
341 devalarm_cancel(&alarms[i]);
342 spin_lock_irqsave(&alarm_slock, flags);
343 }
344 if (alarm_pending | wait_pending) {
345 if (alarm_pending)
346 alarm_dbg(INFO, "%s: clear pending alarms %x\n",
347 __func__, alarm_pending);
348 __pm_relax(&alarm_wake_lock);
349 wait_pending = 0;
350 alarm_pending = 0;
351 }
352 alarm_opened = 0;
353 }
354 spin_unlock_irqrestore(&alarm_slock, flags);
355 return 0;
356}
357
358static void devalarm_triggered(struct devalarm *alarm)
359{
360 unsigned long flags;
361 uint32_t alarm_type_mask = 1U << alarm->type;
362
363 alarm_dbg(INT, "%s: type %d\n", __func__, alarm->type);
364 spin_lock_irqsave(&alarm_slock, flags);
365 if (alarm_enabled & alarm_type_mask) {
366 __pm_wakeup_event(&alarm_wake_lock, 5000); /* 5secs */
367 alarm_enabled &= ~alarm_type_mask;
368 alarm_pending |= alarm_type_mask;
369 wake_up(&alarm_wait_queue);
370 }
371 spin_unlock_irqrestore(&alarm_slock, flags);
372}
373
374
375static enum hrtimer_restart devalarm_hrthandler(struct hrtimer *hrt)
376{
377 struct devalarm *devalrm = container_of(hrt, struct devalarm, u.hrt);
378
379 devalarm_triggered(devalrm);
380 return HRTIMER_NORESTART;
381}
382
383static enum alarmtimer_restart devalarm_alarmhandler(struct alarm *alrm,
384 ktime_t now)
385{
386 struct devalarm *devalrm = container_of(alrm, struct devalarm, u.alrm);
387
388 devalarm_triggered(devalrm);
389 return ALARMTIMER_NORESTART;
390}
391
392
393static const struct file_operations alarm_fops = {
394 .owner = THIS_MODULE,
395 .unlocked_ioctl = alarm_ioctl,
396 .open = alarm_open,
397 .release = alarm_release,
398#ifdef CONFIG_COMPAT
399 .compat_ioctl = alarm_compat_ioctl,
400#endif
401};
402
403static struct miscdevice alarm_device = {
404 .minor = MISC_DYNAMIC_MINOR,
405 .name = "alarm",
406 .fops = &alarm_fops,
407};
408
409static int __init alarm_dev_init(void)
410{
411 int err;
412 int i;
413
414 err = misc_register(&alarm_device);
415 if (err)
416 return err;
417
418 alarm_init(&alarms[ANDROID_ALARM_RTC_WAKEUP].u.alrm,
419 ALARM_REALTIME, devalarm_alarmhandler);
420 hrtimer_init(&alarms[ANDROID_ALARM_RTC].u.hrt,
421 CLOCK_REALTIME, HRTIMER_MODE_ABS);
422 alarm_init(&alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP].u.alrm,
423 ALARM_BOOTTIME, devalarm_alarmhandler);
424 hrtimer_init(&alarms[ANDROID_ALARM_ELAPSED_REALTIME].u.hrt,
425 CLOCK_BOOTTIME, HRTIMER_MODE_ABS);
426 hrtimer_init(&alarms[ANDROID_ALARM_SYSTEMTIME].u.hrt,
427 CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
428
429 for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++) {
430 alarms[i].type = i;
431 if (!is_wakeup(i))
432 alarms[i].u.hrt.function = devalarm_hrthandler;
433 }
434
435 wakeup_source_init(&alarm_wake_lock, "alarm");
436 return 0;
437}
438
439static void __exit alarm_dev_exit(void)
440{
441 misc_deregister(&alarm_device);
442 wakeup_source_trash(&alarm_wake_lock);
443}
444
445module_init(alarm_dev_init);
446module_exit(alarm_dev_exit);
447