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 "android_alarm.h"
26
27 /* XXX - Hack out wakelocks, while they are out of tree */
28 struct wake_lock {
29 int i;
30 };
31 #define wake_lock(x)
32 #define wake_lock_timeout(x, y)
33 #define wake_unlock(x)
34 #define WAKE_LOCK_SUSPEND 0
35 #define wake_lock_init(x, y, z) ((x)->i = 1)
36 #define wake_lock_destroy(x)
37
38 #define ANDROID_ALARM_PRINT_INFO (1U << 0)
39 #define ANDROID_ALARM_PRINT_IO (1U << 1)
40 #define ANDROID_ALARM_PRINT_INT (1U << 2)
41
42
43 static int debug_mask = ANDROID_ALARM_PRINT_INFO;
44 module_param_named(debug_mask, debug_mask, int, S_IRUGO | S_IWUSR | S_IWGRP);
45
46 #define pr_alarm(debug_level_mask, args...) \
47 do { \
48 if (debug_mask & ANDROID_ALARM_PRINT_##debug_level_mask) { \
49 pr_info(args); \
50 } \
51 } while (0)
52
53 #define ANDROID_ALARM_WAKEUP_MASK ( \
54 ANDROID_ALARM_RTC_WAKEUP_MASK | \
55 ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP_MASK)
56
57 /* support old usespace code */
58 #define ANDROID_ALARM_SET_OLD _IOW('a', 2, time_t) /* set alarm */
59 #define ANDROID_ALARM_SET_AND_WAIT_OLD _IOW('a', 3, time_t)
60
61 static int alarm_opened;
62 static DEFINE_SPINLOCK(alarm_slock);
63 static struct wake_lock alarm_wake_lock;
64 static DECLARE_WAIT_QUEUE_HEAD(alarm_wait_queue);
65 static uint32_t alarm_pending;
66 static uint32_t alarm_enabled;
67 static uint32_t wait_pending;
68
69 static struct android_alarm alarms[ANDROID_ALARM_TYPE_COUNT];
70
alarm_ioctl(struct file * file,unsigned int cmd,unsigned long arg)71 static long alarm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
72 {
73 int rv = 0;
74 unsigned long flags;
75 struct timespec new_alarm_time;
76 struct timespec new_rtc_time;
77 struct timespec tmp_time;
78 enum android_alarm_type alarm_type = ANDROID_ALARM_IOCTL_TO_TYPE(cmd);
79 uint32_t alarm_type_mask = 1U << alarm_type;
80
81 if (alarm_type >= ANDROID_ALARM_TYPE_COUNT)
82 return -EINVAL;
83
84 if (ANDROID_ALARM_BASE_CMD(cmd) != ANDROID_ALARM_GET_TIME(0)) {
85 if ((file->f_flags & O_ACCMODE) == O_RDONLY)
86 return -EPERM;
87 if (file->private_data == NULL &&
88 cmd != ANDROID_ALARM_SET_RTC) {
89 spin_lock_irqsave(&alarm_slock, flags);
90 if (alarm_opened) {
91 spin_unlock_irqrestore(&alarm_slock, flags);
92 return -EBUSY;
93 }
94 alarm_opened = 1;
95 file->private_data = (void *)1;
96 spin_unlock_irqrestore(&alarm_slock, flags);
97 }
98 }
99
100 switch (ANDROID_ALARM_BASE_CMD(cmd)) {
101 case ANDROID_ALARM_CLEAR(0):
102 spin_lock_irqsave(&alarm_slock, flags);
103 pr_alarm(IO, "alarm %d clear\n", alarm_type);
104 android_alarm_try_to_cancel(&alarms[alarm_type]);
105 if (alarm_pending) {
106 alarm_pending &= ~alarm_type_mask;
107 if (!alarm_pending && !wait_pending)
108 wake_unlock(&alarm_wake_lock);
109 }
110 alarm_enabled &= ~alarm_type_mask;
111 spin_unlock_irqrestore(&alarm_slock, flags);
112 break;
113
114 case ANDROID_ALARM_SET_OLD:
115 case ANDROID_ALARM_SET_AND_WAIT_OLD:
116 if (get_user(new_alarm_time.tv_sec, (int __user *)arg)) {
117 rv = -EFAULT;
118 goto err1;
119 }
120 new_alarm_time.tv_nsec = 0;
121 goto from_old_alarm_set;
122
123 case ANDROID_ALARM_SET_AND_WAIT(0):
124 case ANDROID_ALARM_SET(0):
125 if (copy_from_user(&new_alarm_time, (void __user *)arg,
126 sizeof(new_alarm_time))) {
127 rv = -EFAULT;
128 goto err1;
129 }
130 from_old_alarm_set:
131 spin_lock_irqsave(&alarm_slock, flags);
132 pr_alarm(IO, "alarm %d set %ld.%09ld\n", alarm_type,
133 new_alarm_time.tv_sec, new_alarm_time.tv_nsec);
134 alarm_enabled |= alarm_type_mask;
135 android_alarm_start_range(&alarms[alarm_type],
136 timespec_to_ktime(new_alarm_time),
137 timespec_to_ktime(new_alarm_time));
138 spin_unlock_irqrestore(&alarm_slock, flags);
139 if (ANDROID_ALARM_BASE_CMD(cmd) != ANDROID_ALARM_SET_AND_WAIT(0)
140 && cmd != ANDROID_ALARM_SET_AND_WAIT_OLD)
141 break;
142 /* fall though */
143 case ANDROID_ALARM_WAIT:
144 spin_lock_irqsave(&alarm_slock, flags);
145 pr_alarm(IO, "alarm wait\n");
146 if (!alarm_pending && wait_pending) {
147 wake_unlock(&alarm_wake_lock);
148 wait_pending = 0;
149 }
150 spin_unlock_irqrestore(&alarm_slock, flags);
151 rv = wait_event_interruptible(alarm_wait_queue, alarm_pending);
152 if (rv)
153 goto err1;
154 spin_lock_irqsave(&alarm_slock, flags);
155 rv = alarm_pending;
156 wait_pending = 1;
157 alarm_pending = 0;
158 spin_unlock_irqrestore(&alarm_slock, flags);
159 break;
160 case ANDROID_ALARM_SET_RTC:
161 if (copy_from_user(&new_rtc_time, (void __user *)arg,
162 sizeof(new_rtc_time))) {
163 rv = -EFAULT;
164 goto err1;
165 }
166 rv = android_alarm_set_rtc(new_rtc_time);
167 spin_lock_irqsave(&alarm_slock, flags);
168 alarm_pending |= ANDROID_ALARM_TIME_CHANGE_MASK;
169 wake_up(&alarm_wait_queue);
170 spin_unlock_irqrestore(&alarm_slock, flags);
171 if (rv < 0)
172 goto err1;
173 break;
174 case ANDROID_ALARM_GET_TIME(0):
175 switch (alarm_type) {
176 case ANDROID_ALARM_RTC_WAKEUP:
177 case ANDROID_ALARM_RTC:
178 getnstimeofday(&tmp_time);
179 break;
180 case ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP:
181 case ANDROID_ALARM_ELAPSED_REALTIME:
182 tmp_time =
183 ktime_to_timespec(alarm_get_elapsed_realtime());
184 break;
185 case ANDROID_ALARM_TYPE_COUNT:
186 case ANDROID_ALARM_SYSTEMTIME:
187 ktime_get_ts(&tmp_time);
188 break;
189 }
190 if (copy_to_user((void __user *)arg, &tmp_time,
191 sizeof(tmp_time))) {
192 rv = -EFAULT;
193 goto err1;
194 }
195 break;
196
197 default:
198 rv = -EINVAL;
199 goto err1;
200 }
201 err1:
202 return rv;
203 }
204
alarm_open(struct inode * inode,struct file * file)205 static int alarm_open(struct inode *inode, struct file *file)
206 {
207 file->private_data = NULL;
208 return 0;
209 }
210
alarm_release(struct inode * inode,struct file * file)211 static int alarm_release(struct inode *inode, struct file *file)
212 {
213 int i;
214 unsigned long flags;
215
216 spin_lock_irqsave(&alarm_slock, flags);
217 if (file->private_data != 0) {
218 for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++) {
219 uint32_t alarm_type_mask = 1U << i;
220 if (alarm_enabled & alarm_type_mask) {
221 pr_alarm(INFO, "alarm_release: clear alarm, "
222 "pending %d\n",
223 !!(alarm_pending & alarm_type_mask));
224 alarm_enabled &= ~alarm_type_mask;
225 }
226 spin_unlock_irqrestore(&alarm_slock, flags);
227 android_alarm_cancel(&alarms[i]);
228 spin_lock_irqsave(&alarm_slock, flags);
229 }
230 if (alarm_pending | wait_pending) {
231 if (alarm_pending)
232 pr_alarm(INFO, "alarm_release: clear "
233 "pending alarms %x\n", alarm_pending);
234 wake_unlock(&alarm_wake_lock);
235 wait_pending = 0;
236 alarm_pending = 0;
237 }
238 alarm_opened = 0;
239 }
240 spin_unlock_irqrestore(&alarm_slock, flags);
241 return 0;
242 }
243
alarm_triggered(struct android_alarm * alarm)244 static void alarm_triggered(struct android_alarm *alarm)
245 {
246 unsigned long flags;
247 uint32_t alarm_type_mask = 1U << alarm->type;
248
249 pr_alarm(INT, "alarm_triggered type %d\n", alarm->type);
250 spin_lock_irqsave(&alarm_slock, flags);
251 if (alarm_enabled & alarm_type_mask) {
252 wake_lock_timeout(&alarm_wake_lock, 5 * HZ);
253 alarm_enabled &= ~alarm_type_mask;
254 alarm_pending |= alarm_type_mask;
255 wake_up(&alarm_wait_queue);
256 }
257 spin_unlock_irqrestore(&alarm_slock, flags);
258 }
259
260 static const struct file_operations alarm_fops = {
261 .owner = THIS_MODULE,
262 .unlocked_ioctl = alarm_ioctl,
263 .open = alarm_open,
264 .release = alarm_release,
265 };
266
267 static struct miscdevice alarm_device = {
268 .minor = MISC_DYNAMIC_MINOR,
269 .name = "alarm",
270 .fops = &alarm_fops,
271 };
272
alarm_dev_init(void)273 static int __init alarm_dev_init(void)
274 {
275 int err;
276 int i;
277
278 err = misc_register(&alarm_device);
279 if (err)
280 return err;
281
282 for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++)
283 android_alarm_init(&alarms[i], i, alarm_triggered);
284 wake_lock_init(&alarm_wake_lock, WAKE_LOCK_SUSPEND, "alarm");
285
286 return 0;
287 }
288
alarm_dev_exit(void)289 static void __exit alarm_dev_exit(void)
290 {
291 misc_deregister(&alarm_device);
292 wake_lock_destroy(&alarm_wake_lock);
293 }
294
295 module_init(alarm_dev_init);
296 module_exit(alarm_dev_exit);
297
298