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
32
33static int debug_mask = ANDROID_ALARM_PRINT_INFO;
34module_param_named(debug_mask, debug_mask, int, S_IRUGO | S_IWUSR | S_IWGRP);
35
36#define pr_alarm(debug_level_mask, args...) \
37 do { \
38 if (debug_mask & ANDROID_ALARM_PRINT_##debug_level_mask) { \
39 pr_info(args); \
40 } \
41 } while (0)
42
43#define ANDROID_ALARM_WAKEUP_MASK ( \
44 ANDROID_ALARM_RTC_WAKEUP_MASK | \
45 ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP_MASK)
46
47/* support old userspace code */
48#define ANDROID_ALARM_SET_OLD _IOW('a', 2, time_t) /* set alarm */
49#define ANDROID_ALARM_SET_AND_WAIT_OLD _IOW('a', 3, time_t)
50
51static int alarm_opened;
52static DEFINE_SPINLOCK(alarm_slock);
53static struct wakeup_source alarm_wake_lock;
54static DECLARE_WAIT_QUEUE_HEAD(alarm_wait_queue);
55static uint32_t alarm_pending;
56static uint32_t alarm_enabled;
57static uint32_t wait_pending;
58
59struct devalarm {
60 union {
61 struct hrtimer hrt;
62 struct alarm alrm;
63 } u;
64 enum android_alarm_type type;
65};
66
67static struct devalarm alarms[ANDROID_ALARM_TYPE_COUNT];
68
69
70static int is_wakeup(enum android_alarm_type type)
71{
72 if (type == ANDROID_ALARM_RTC_WAKEUP ||
73 type == ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP)
74 return 1;
75 return 0;
76}
77
78
79static void devalarm_start(struct devalarm *alrm, ktime_t exp)
80{
81 if (is_wakeup(alrm->type))
82 alarm_start(&alrm->u.alrm, exp);
83 else
84 hrtimer_start(&alrm->u.hrt, exp, HRTIMER_MODE_ABS);
85}
86
87
88static int devalarm_try_to_cancel(struct devalarm *alrm)
89{
90 int ret;
91 if (is_wakeup(alrm->type))
92 ret = alarm_try_to_cancel(&alrm->u.alrm);
93 else
94 ret = hrtimer_try_to_cancel(&alrm->u.hrt);
95 return ret;
96}
97
98static void devalarm_cancel(struct devalarm *alrm)
99{
100 if (is_wakeup(alrm->type))
101 alarm_cancel(&alrm->u.alrm);
102 else
103 hrtimer_cancel(&alrm->u.hrt);
104}
105
106
107static long alarm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
108{
109 int rv = 0;
110 unsigned long flags;
111 struct timespec new_alarm_time;
112 struct timespec new_rtc_time;
113 struct timespec tmp_time;
114 struct rtc_time new_rtc_tm;
115 struct rtc_device *rtc_dev;
116 enum android_alarm_type alarm_type = ANDROID_ALARM_IOCTL_TO_TYPE(cmd);
117 uint32_t alarm_type_mask = 1U << alarm_type;
118
119 if (alarm_type >= ANDROID_ALARM_TYPE_COUNT)
120 return -EINVAL;
121
122 if (ANDROID_ALARM_BASE_CMD(cmd) != ANDROID_ALARM_GET_TIME(0)) {
123 if ((file->f_flags & O_ACCMODE) == O_RDONLY)
124 return -EPERM;
125 if (file->private_data == NULL &&
126 cmd != ANDROID_ALARM_SET_RTC) {
127 spin_lock_irqsave(&alarm_slock, flags);
128 if (alarm_opened) {
129 spin_unlock_irqrestore(&alarm_slock, flags);
130 return -EBUSY;
131 }
132 alarm_opened = 1;
133 file->private_data = (void *)1;
134 spin_unlock_irqrestore(&alarm_slock, flags);
135 }
136 }
137
138 switch (ANDROID_ALARM_BASE_CMD(cmd)) {
139 case ANDROID_ALARM_CLEAR(0):
140 spin_lock_irqsave(&alarm_slock, flags);
141 pr_alarm(IO, "alarm %d clear\n", alarm_type);
142 devalarm_try_to_cancel(&alarms[alarm_type]);
143 if (alarm_pending) {
144 alarm_pending &= ~alarm_type_mask;
145 if (!alarm_pending && !wait_pending)
146 __pm_relax(&alarm_wake_lock);
147 }
148 alarm_enabled &= ~alarm_type_mask;
149 spin_unlock_irqrestore(&alarm_slock, flags);
150 break;
151
152 case ANDROID_ALARM_SET_OLD:
153 case ANDROID_ALARM_SET_AND_WAIT_OLD:
154 if (get_user(new_alarm_time.tv_sec, (int __user *)arg)) {
155 rv = -EFAULT;
156 goto err1;
157 }
158 new_alarm_time.tv_nsec = 0;
159 goto from_old_alarm_set;
160
161 case ANDROID_ALARM_SET_AND_WAIT(0):
162 case ANDROID_ALARM_SET(0):
163 if (copy_from_user(&new_alarm_time, (void __user *)arg,
164 sizeof(new_alarm_time))) {
165 rv = -EFAULT;
166 goto err1;
167 }
168from_old_alarm_set:
169 spin_lock_irqsave(&alarm_slock, flags);
170 pr_alarm(IO, "alarm %d set %ld.%09ld\n", alarm_type,
171 new_alarm_time.tv_sec, new_alarm_time.tv_nsec);
172 alarm_enabled |= alarm_type_mask;
173 devalarm_start(&alarms[alarm_type],
174 timespec_to_ktime(new_alarm_time));
175 spin_unlock_irqrestore(&alarm_slock, flags);
176 if (ANDROID_ALARM_BASE_CMD(cmd) != ANDROID_ALARM_SET_AND_WAIT(0)
177 && cmd != ANDROID_ALARM_SET_AND_WAIT_OLD)
178 break;
179 /* fall though */
180 case ANDROID_ALARM_WAIT:
181 spin_lock_irqsave(&alarm_slock, flags);
182 pr_alarm(IO, "alarm wait\n");
183 if (!alarm_pending && wait_pending) {
184 __pm_relax(&alarm_wake_lock);
185 wait_pending = 0;
186 }
187 spin_unlock_irqrestore(&alarm_slock, flags);
188 rv = wait_event_interruptible(alarm_wait_queue, alarm_pending);
189 if (rv)
190 goto err1;
191 spin_lock_irqsave(&alarm_slock, flags);
192 rv = alarm_pending;
193 wait_pending = 1;
194 alarm_pending = 0;
195 spin_unlock_irqrestore(&alarm_slock, flags);
196 break;
197 case ANDROID_ALARM_SET_RTC:
198 if (copy_from_user(&new_rtc_time, (void __user *)arg,
199 sizeof(new_rtc_time))) {
200 rv = -EFAULT;
201 goto err1;
202 }
203 rtc_time_to_tm(new_rtc_time.tv_sec, &new_rtc_tm);
204 rtc_dev = alarmtimer_get_rtcdev();
205 rv = do_settimeofday(&new_rtc_time);
206 if (rv < 0)
207 goto err1;
208 if (rtc_dev)
209 rv = rtc_set_time(rtc_dev, &new_rtc_tm);
210 spin_lock_irqsave(&alarm_slock, flags);
211 alarm_pending |= ANDROID_ALARM_TIME_CHANGE_MASK;
212 wake_up(&alarm_wait_queue);
213 spin_unlock_irqrestore(&alarm_slock, flags);
214 if (rv < 0)
215 goto err1;
216 break;
217 case ANDROID_ALARM_GET_TIME(0):
218 switch (alarm_type) {
219 case ANDROID_ALARM_RTC_WAKEUP:
220 case ANDROID_ALARM_RTC:
221 getnstimeofday(&tmp_time);
222 break;
223 case ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP:
224 case ANDROID_ALARM_ELAPSED_REALTIME:
225 get_monotonic_boottime(&tmp_time);
226 break;
227 case ANDROID_ALARM_TYPE_COUNT:
228 case ANDROID_ALARM_SYSTEMTIME:
229 ktime_get_ts(&tmp_time);
230 break;
231 }
232 if (copy_to_user((void __user *)arg, &tmp_time,
233 sizeof(tmp_time))) {
234 rv = -EFAULT;
235 goto err1;
236 }
237 break;
238
239 default:
240 rv = -EINVAL;
241 goto err1;
242 }
243err1:
244 return rv;
245}
246
247static int alarm_open(struct inode *inode, struct file *file)
248{
249 file->private_data = NULL;
250 return 0;
251}
252
253static int alarm_release(struct inode *inode, struct file *file)
254{
255 int i;
256 unsigned long flags;
257
258 spin_lock_irqsave(&alarm_slock, flags);
259 if (file->private_data != 0) {
260 for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++) {
261 uint32_t alarm_type_mask = 1U << i;
262 if (alarm_enabled & alarm_type_mask) {
263 pr_alarm(INFO, "alarm_release: clear alarm, "
264 "pending %d\n",
265 !!(alarm_pending & alarm_type_mask));
266 alarm_enabled &= ~alarm_type_mask;
267 }
268 spin_unlock_irqrestore(&alarm_slock, flags);
269 devalarm_cancel(&alarms[i]);
270 spin_lock_irqsave(&alarm_slock, flags);
271 }
272 if (alarm_pending | wait_pending) {
273 if (alarm_pending)
274 pr_alarm(INFO, "alarm_release: clear "
275 "pending alarms %x\n", alarm_pending);
276 __pm_relax(&alarm_wake_lock);
277 wait_pending = 0;
278 alarm_pending = 0;
279 }
280 alarm_opened = 0;
281 }
282 spin_unlock_irqrestore(&alarm_slock, flags);
283 return 0;
284}
285
286static void devalarm_triggered(struct devalarm *alarm)
287{
288 unsigned long flags;
289 uint32_t alarm_type_mask = 1U << alarm->type;
290
291 pr_alarm(INT, "devalarm_triggered type %d\n", alarm->type);
292 spin_lock_irqsave(&alarm_slock, flags);
293 if (alarm_enabled & alarm_type_mask) {
294 __pm_wakeup_event(&alarm_wake_lock, 5000); /* 5secs */
295 alarm_enabled &= ~alarm_type_mask;
296 alarm_pending |= alarm_type_mask;
297 wake_up(&alarm_wait_queue);
298 }
299 spin_unlock_irqrestore(&alarm_slock, flags);
300}
301
302
303static enum hrtimer_restart devalarm_hrthandler(struct hrtimer *hrt)
304{
305 struct devalarm *devalrm = container_of(hrt, struct devalarm, u.hrt);
306
307 devalarm_triggered(devalrm);
308 return HRTIMER_NORESTART;
309}
310
311static enum alarmtimer_restart devalarm_alarmhandler(struct alarm *alrm,
312 ktime_t now)
313{
314 struct devalarm *devalrm = container_of(alrm, struct devalarm, u.alrm);
315
316 devalarm_triggered(devalrm);
317 return ALARMTIMER_NORESTART;
318}
319
320
321static const struct file_operations alarm_fops = {
322 .owner = THIS_MODULE,
323 .unlocked_ioctl = alarm_ioctl,
324 .open = alarm_open,
325 .release = alarm_release,
326};
327
328static struct miscdevice alarm_device = {
329 .minor = MISC_DYNAMIC_MINOR,
330 .name = "alarm",
331 .fops = &alarm_fops,
332};
333
334static int __init alarm_dev_init(void)
335{
336 int err;
337 int i;
338
339 err = misc_register(&alarm_device);
340 if (err)
341 return err;
342
343 alarm_init(&alarms[ANDROID_ALARM_RTC_WAKEUP].u.alrm,
344 ALARM_REALTIME, devalarm_alarmhandler);
345 hrtimer_init(&alarms[ANDROID_ALARM_RTC].u.hrt,
346 CLOCK_REALTIME, HRTIMER_MODE_ABS);
347 alarm_init(&alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP].u.alrm,
348 ALARM_BOOTTIME, devalarm_alarmhandler);
349 hrtimer_init(&alarms[ANDROID_ALARM_ELAPSED_REALTIME].u.hrt,
350 CLOCK_BOOTTIME, HRTIMER_MODE_ABS);
351 hrtimer_init(&alarms[ANDROID_ALARM_SYSTEMTIME].u.hrt,
352 CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
353
354 for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++) {
355 alarms[i].type = i;
356 if (!is_wakeup(i))
357 alarms[i].u.hrt.function = devalarm_hrthandler;
358 }
359
360 wakeup_source_init(&alarm_wake_lock, "alarm");
361 return 0;
362}
363
364static void __exit alarm_dev_exit(void)
365{
366 misc_deregister(&alarm_device);
367 wakeup_source_trash(&alarm_wake_lock);
368}
369
370module_init(alarm_dev_init);
371module_exit(alarm_dev_exit);
372