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
75static void devalarm_start(struct devalarm *alrm, ktime_t exp)
76{
77 if (is_wakeup(alrm->type))
78 alarm_start(&alrm->u.alrm, exp);
79 else
80 hrtimer_start(&alrm->u.hrt, exp, HRTIMER_MODE_ABS);
81}
82
83static int devalarm_try_to_cancel(struct devalarm *alrm)
84{
85 if (is_wakeup(alrm->type))
86 return alarm_try_to_cancel(&alrm->u.alrm);
87 return hrtimer_try_to_cancel(&alrm->u.hrt);
88}
89
90static void devalarm_cancel(struct devalarm *alrm)
91{
92 if (is_wakeup(alrm->type))
93 alarm_cancel(&alrm->u.alrm);
94 else
95 hrtimer_cancel(&alrm->u.hrt);
96}
97
98static void alarm_clear(enum android_alarm_type alarm_type)
99{
100 uint32_t alarm_type_mask = 1U << alarm_type;
101 unsigned long flags;
102
103 spin_lock_irqsave(&alarm_slock, flags);
104 alarm_dbg(IO, "alarm %d clear\n", alarm_type);
105 devalarm_try_to_cancel(&alarms[alarm_type]);
106 if (alarm_pending) {
107 alarm_pending &= ~alarm_type_mask;
108 if (!alarm_pending && !wait_pending)
109 __pm_relax(&alarm_wake_lock);
110 }
111 alarm_enabled &= ~alarm_type_mask;
112 spin_unlock_irqrestore(&alarm_slock, flags);
113}
114
115static void alarm_set(enum android_alarm_type alarm_type,
116 struct timespec *ts)
117{
118 uint32_t alarm_type_mask = 1U << alarm_type;
119 unsigned long flags;
120
121 spin_lock_irqsave(&alarm_slock, flags);
122 alarm_dbg(IO, "alarm %d set %ld.%09ld\n",
123 alarm_type, ts->tv_sec, ts->tv_nsec);
124 alarm_enabled |= alarm_type_mask;
125 devalarm_start(&alarms[alarm_type], timespec_to_ktime(*ts));
126 spin_unlock_irqrestore(&alarm_slock, flags);
127}
128
129static int alarm_wait(void)
130{
131 unsigned long flags;
132 int rv = 0;
133
134 spin_lock_irqsave(&alarm_slock, flags);
135 alarm_dbg(IO, "alarm wait\n");
136 if (!alarm_pending && wait_pending) {
137 __pm_relax(&alarm_wake_lock);
138 wait_pending = 0;
139 }
140 spin_unlock_irqrestore(&alarm_slock, flags);
141
142 rv = wait_event_interruptible(alarm_wait_queue, alarm_pending);
143 if (rv)
144 return rv;
145
146 spin_lock_irqsave(&alarm_slock, flags);
147 rv = alarm_pending;
148 wait_pending = 1;
149 alarm_pending = 0;
150 spin_unlock_irqrestore(&alarm_slock, flags);
151
152 return rv;
153}
154
155static int alarm_set_rtc(struct timespec *ts)
156{
157 struct rtc_time new_rtc_tm;
158 struct rtc_device *rtc_dev;
159 unsigned long flags;
160 int rv = 0;
161
162 rtc_time_to_tm(ts->tv_sec, &new_rtc_tm);
163 rtc_dev = alarmtimer_get_rtcdev();
164 rv = do_settimeofday(ts);
165 if (rv < 0)
166 return rv;
167 if (rtc_dev)
168 rv = rtc_set_time(rtc_dev, &new_rtc_tm);
169
170 spin_lock_irqsave(&alarm_slock, flags);
171 alarm_pending |= ANDROID_ALARM_TIME_CHANGE_MASK;
172 wake_up(&alarm_wait_queue);
173 spin_unlock_irqrestore(&alarm_slock, flags);
174
175 return rv;
176}
177
178static int alarm_get_time(enum android_alarm_type alarm_type,
179 struct timespec *ts)
180{
181 int rv = 0;
182
183 switch (alarm_type) {
184 case ANDROID_ALARM_RTC_WAKEUP:
185 case ANDROID_ALARM_RTC:
186 getnstimeofday(ts);
187 break;
188 case ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP:
189 case ANDROID_ALARM_ELAPSED_REALTIME:
190 get_monotonic_boottime(ts);
191 break;
192 case ANDROID_ALARM_SYSTEMTIME:
193 ktime_get_ts(ts);
194 break;
195 default:
196 rv = -EINVAL;
197 }
198 return rv;
199}
200
201static long alarm_do_ioctl(struct file *file, unsigned int cmd,
202 struct timespec *ts)
203{
204 int rv = 0;
205 unsigned long flags;
206 enum android_alarm_type alarm_type = ANDROID_ALARM_IOCTL_TO_TYPE(cmd);
207
208 if (alarm_type >= ANDROID_ALARM_TYPE_COUNT)
209 return -EINVAL;
210
211 if (ANDROID_ALARM_BASE_CMD(cmd) != ANDROID_ALARM_GET_TIME(0)) {
212 if ((file->f_flags & O_ACCMODE) == O_RDONLY)
213 return -EPERM;
214 if (file->private_data == NULL &&
215 cmd != ANDROID_ALARM_SET_RTC) {
216 spin_lock_irqsave(&alarm_slock, flags);
217 if (alarm_opened) {
218 spin_unlock_irqrestore(&alarm_slock, flags);
219 return -EBUSY;
220 }
221 alarm_opened = 1;
222 file->private_data = (void *)1;
223 spin_unlock_irqrestore(&alarm_slock, flags);
224 }
225 }
226
227 switch (ANDROID_ALARM_BASE_CMD(cmd)) {
228 case ANDROID_ALARM_CLEAR(0):
229 alarm_clear(alarm_type);
230 break;
231 case ANDROID_ALARM_SET(0):
232 alarm_set(alarm_type, ts);
233 break;
234 case ANDROID_ALARM_SET_AND_WAIT(0):
235 alarm_set(alarm_type, ts);
236 /* fall though */
237 case ANDROID_ALARM_WAIT:
238 rv = alarm_wait();
239 break;
240 case ANDROID_ALARM_SET_RTC:
241 rv = alarm_set_rtc(ts);
242 break;
243 case ANDROID_ALARM_GET_TIME(0):
244 rv = alarm_get_time(alarm_type, ts);
245 break;
246
247 default:
248 rv = -EINVAL;
249 }
250 return rv;
251}
252
253static long alarm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
254{
255
256 struct timespec ts;
257 int rv;
258
259 switch (ANDROID_ALARM_BASE_CMD(cmd)) {
260 case ANDROID_ALARM_SET_AND_WAIT(0):
261 case ANDROID_ALARM_SET(0):
262 case ANDROID_ALARM_SET_RTC:
263 if (copy_from_user(&ts, (void __user *)arg, sizeof(ts)))
264 return -EFAULT;
265 break;
266 }
267
268 rv = alarm_do_ioctl(file, cmd, &ts);
269 if (rv)
270 return rv;
271
272 switch (ANDROID_ALARM_BASE_CMD(cmd)) {
273 case ANDROID_ALARM_GET_TIME(0):
274 if (copy_to_user((void __user *)arg, &ts, sizeof(ts)))
275 return -EFAULT;
276 break;
277 }
278
279 return 0;
280}
281
282#ifdef CONFIG_COMPAT
283static long alarm_compat_ioctl(struct file *file, unsigned int cmd,
284 unsigned long arg)
285{
286
287 struct timespec ts;
288 int rv;
289
290 switch (ANDROID_ALARM_BASE_CMD(cmd)) {
291 case ANDROID_ALARM_SET_AND_WAIT_COMPAT(0):
292 case ANDROID_ALARM_SET_COMPAT(0):
293 case ANDROID_ALARM_SET_RTC_COMPAT:
294 if (compat_get_timespec(&ts, (void __user *)arg))
295 return -EFAULT;
296 /* fall through */
297 case ANDROID_ALARM_GET_TIME_COMPAT(0):
298 cmd = ANDROID_ALARM_COMPAT_TO_NORM(cmd);
299 break;
300 }
301
302 rv = alarm_do_ioctl(file, cmd, &ts);
303 if (rv)
304 return rv;
305
306 switch (ANDROID_ALARM_BASE_CMD(cmd)) {
307 case ANDROID_ALARM_GET_TIME(0): /* NOTE: we modified cmd above */
308 if (compat_put_timespec(&ts, (void __user *)arg))
309 return -EFAULT;
310 break;
311 }
312
313 return 0;
314}
315#endif
316
317static int alarm_open(struct inode *inode, struct file *file)
318{
319 file->private_data = NULL;
320 return 0;
321}
322
323static int alarm_release(struct inode *inode, struct file *file)
324{
325 int i;
326 unsigned long flags;
327
328 spin_lock_irqsave(&alarm_slock, flags);
329 if (file->private_data) {
330 for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++) {
331 uint32_t alarm_type_mask = 1U << i;
332 if (alarm_enabled & alarm_type_mask) {
333 alarm_dbg(INFO,
334 "%s: clear alarm, pending %d\n",
335 __func__,
336 !!(alarm_pending & alarm_type_mask));
337 alarm_enabled &= ~alarm_type_mask;
338 }
339 spin_unlock_irqrestore(&alarm_slock, flags);
340 devalarm_cancel(&alarms[i]);
341 spin_lock_irqsave(&alarm_slock, flags);
342 }
343 if (alarm_pending | wait_pending) {
344 if (alarm_pending)
345 alarm_dbg(INFO, "%s: clear pending alarms %x\n",
346 __func__, alarm_pending);
347 __pm_relax(&alarm_wake_lock);
348 wait_pending = 0;
349 alarm_pending = 0;
350 }
351 alarm_opened = 0;
352 }
353 spin_unlock_irqrestore(&alarm_slock, flags);
354 return 0;
355}
356
357static void devalarm_triggered(struct devalarm *alarm)
358{
359 unsigned long flags;
360 uint32_t alarm_type_mask = 1U << alarm->type;
361
362 alarm_dbg(INT, "%s: type %d\n", __func__, alarm->type);
363 spin_lock_irqsave(&alarm_slock, flags);
364 if (alarm_enabled & alarm_type_mask) {
365 __pm_wakeup_event(&alarm_wake_lock, 5000); /* 5secs */
366 alarm_enabled &= ~alarm_type_mask;
367 alarm_pending |= alarm_type_mask;
368 wake_up(&alarm_wait_queue);
369 }
370 spin_unlock_irqrestore(&alarm_slock, flags);
371}
372
373static enum hrtimer_restart devalarm_hrthandler(struct hrtimer *hrt)
374{
375 struct devalarm *devalrm = container_of(hrt, struct devalarm, u.hrt);
376
377 devalarm_triggered(devalrm);
378 return HRTIMER_NORESTART;
379}
380
381static enum alarmtimer_restart devalarm_alarmhandler(struct alarm *alrm,
382 ktime_t now)
383{
384 struct devalarm *devalrm = container_of(alrm, struct devalarm, u.alrm);
385
386 devalarm_triggered(devalrm);
387 return ALARMTIMER_NORESTART;
388}
389
390
391static const struct file_operations alarm_fops = {
392 .owner = THIS_MODULE,
393 .unlocked_ioctl = alarm_ioctl,
394 .open = alarm_open,
395 .release = alarm_release,
396#ifdef CONFIG_COMPAT
397 .compat_ioctl = alarm_compat_ioctl,
398#endif
399};
400
401static struct miscdevice alarm_device = {
402 .minor = MISC_DYNAMIC_MINOR,
403 .name = "alarm",
404 .fops = &alarm_fops,
405};
406
407static int __init alarm_dev_init(void)
408{
409 int err;
410 int i;
411
412 err = misc_register(&alarm_device);
413 if (err)
414 return err;
415
416 alarm_init(&alarms[ANDROID_ALARM_RTC_WAKEUP].u.alrm,
417 ALARM_REALTIME, devalarm_alarmhandler);
418 hrtimer_init(&alarms[ANDROID_ALARM_RTC].u.hrt,
419 CLOCK_REALTIME, HRTIMER_MODE_ABS);
420 alarm_init(&alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP].u.alrm,
421 ALARM_BOOTTIME, devalarm_alarmhandler);
422 hrtimer_init(&alarms[ANDROID_ALARM_ELAPSED_REALTIME].u.hrt,
423 CLOCK_BOOTTIME, HRTIMER_MODE_ABS);
424 hrtimer_init(&alarms[ANDROID_ALARM_SYSTEMTIME].u.hrt,
425 CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
426
427 for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++) {
428 alarms[i].type = i;
429 if (!is_wakeup(i))
430 alarms[i].u.hrt.function = devalarm_hrthandler;
431 }
432
433 wakeup_source_init(&alarm_wake_lock, "alarm");
434 return 0;
435}
436
437static void __exit alarm_dev_exit(void)
438{
439 misc_deregister(&alarm_device);
440 wakeup_source_trash(&alarm_wake_lock);
441}
442
443module_init(alarm_dev_init);
444module_exit(alarm_dev_exit);
445