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12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/time.h>
15#include <linux/rtc.h>
16#include <linux/poll.h>
17#include <linux/proc_fs.h>
18#include <linux/miscdevice.h>
19#include <linux/spinlock.h>
20#include <linux/capability.h>
21#include <linux/device.h>
22#include <linux/mutex.h>
23#include <linux/rtc.h>
24
25#include <asm/rtc.h>
26#include <asm/semaphore.h>
27
28static DECLARE_WAIT_QUEUE_HEAD(rtc_wait);
29static struct fasync_struct *rtc_async_queue;
30
31
32
33
34static DEFINE_SPINLOCK(rtc_lock);
35static unsigned long rtc_irq_data;
36
37
38
39
40static DEFINE_MUTEX(rtc_mutex);
41static unsigned long rtc_inuse;
42static struct rtc_ops *rtc_ops;
43
44#define rtc_epoch 1900UL
45
46
47
48
49
50void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now, struct rtc_time *alrm)
51{
52 unsigned long next_time;
53 unsigned long now_time;
54
55 next->tm_year = now->tm_year;
56 next->tm_mon = now->tm_mon;
57 next->tm_mday = now->tm_mday;
58 next->tm_hour = alrm->tm_hour;
59 next->tm_min = alrm->tm_min;
60 next->tm_sec = alrm->tm_sec;
61
62 rtc_tm_to_time(now, &now_time);
63 rtc_tm_to_time(next, &next_time);
64
65 if (next_time < now_time) {
66
67 next_time += 60 * 60 * 24;
68 rtc_time_to_tm(next_time, next);
69 }
70}
71EXPORT_SYMBOL(rtc_next_alarm_time);
72
73static inline int rtc_arm_read_time(struct rtc_ops *ops, struct rtc_time *tm)
74{
75 memset(tm, 0, sizeof(struct rtc_time));
76 return ops->read_time(tm);
77}
78
79static inline int rtc_arm_set_time(struct rtc_ops *ops, struct rtc_time *tm)
80{
81 int ret;
82
83 ret = rtc_valid_tm(tm);
84 if (ret == 0)
85 ret = ops->set_time(tm);
86
87 return ret;
88}
89
90static inline int rtc_arm_read_alarm(struct rtc_ops *ops, struct rtc_wkalrm *alrm)
91{
92 int ret = -EINVAL;
93 if (ops->read_alarm) {
94 memset(alrm, 0, sizeof(struct rtc_wkalrm));
95 ret = ops->read_alarm(alrm);
96 }
97 return ret;
98}
99
100static inline int rtc_arm_set_alarm(struct rtc_ops *ops, struct rtc_wkalrm *alrm)
101{
102 int ret = -EINVAL;
103 if (ops->set_alarm)
104 ret = ops->set_alarm(alrm);
105 return ret;
106}
107
108void rtc_update(unsigned long num, unsigned long events)
109{
110 spin_lock(&rtc_lock);
111 rtc_irq_data = (rtc_irq_data + (num << 8)) | events;
112 spin_unlock(&rtc_lock);
113
114 wake_up_interruptible(&rtc_wait);
115 kill_fasync(&rtc_async_queue, SIGIO, POLL_IN);
116}
117EXPORT_SYMBOL(rtc_update);
118
119
120static ssize_t
121rtc_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
122{
123 DECLARE_WAITQUEUE(wait, current);
124 unsigned long data;
125 ssize_t ret;
126
127 if (count < sizeof(unsigned long))
128 return -EINVAL;
129
130 add_wait_queue(&rtc_wait, &wait);
131 do {
132 __set_current_state(TASK_INTERRUPTIBLE);
133
134 spin_lock_irq(&rtc_lock);
135 data = rtc_irq_data;
136 rtc_irq_data = 0;
137 spin_unlock_irq(&rtc_lock);
138
139 if (data != 0) {
140 ret = 0;
141 break;
142 }
143 if (file->f_flags & O_NONBLOCK) {
144 ret = -EAGAIN;
145 break;
146 }
147 if (signal_pending(current)) {
148 ret = -ERESTARTSYS;
149 break;
150 }
151 schedule();
152 } while (1);
153 set_current_state(TASK_RUNNING);
154 remove_wait_queue(&rtc_wait, &wait);
155
156 if (ret == 0) {
157 ret = put_user(data, (unsigned long __user *)buf);
158 if (ret == 0)
159 ret = sizeof(unsigned long);
160 }
161 return ret;
162}
163
164static unsigned int rtc_poll(struct file *file, poll_table *wait)
165{
166 unsigned long data;
167
168 poll_wait(file, &rtc_wait, wait);
169
170 spin_lock_irq(&rtc_lock);
171 data = rtc_irq_data;
172 spin_unlock_irq(&rtc_lock);
173
174 return data != 0 ? POLLIN | POLLRDNORM : 0;
175}
176
177static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
178 unsigned long arg)
179{
180 struct rtc_ops *ops = file->private_data;
181 struct rtc_time tm;
182 struct rtc_wkalrm alrm;
183 void __user *uarg = (void __user *)arg;
184 int ret = -EINVAL;
185
186 switch (cmd) {
187 case RTC_ALM_READ:
188 ret = rtc_arm_read_alarm(ops, &alrm);
189 if (ret)
190 break;
191 ret = copy_to_user(uarg, &alrm.time, sizeof(tm));
192 if (ret)
193 ret = -EFAULT;
194 break;
195
196 case RTC_ALM_SET:
197 ret = copy_from_user(&alrm.time, uarg, sizeof(tm));
198 if (ret) {
199 ret = -EFAULT;
200 break;
201 }
202 alrm.enabled = 0;
203 alrm.pending = 0;
204 alrm.time.tm_mday = -1;
205 alrm.time.tm_mon = -1;
206 alrm.time.tm_year = -1;
207 alrm.time.tm_wday = -1;
208 alrm.time.tm_yday = -1;
209 alrm.time.tm_isdst = -1;
210 ret = rtc_arm_set_alarm(ops, &alrm);
211 break;
212
213 case RTC_RD_TIME:
214 ret = rtc_arm_read_time(ops, &tm);
215 if (ret)
216 break;
217 ret = copy_to_user(uarg, &tm, sizeof(tm));
218 if (ret)
219 ret = -EFAULT;
220 break;
221
222 case RTC_SET_TIME:
223 if (!capable(CAP_SYS_TIME)) {
224 ret = -EACCES;
225 break;
226 }
227 ret = copy_from_user(&tm, uarg, sizeof(tm));
228 if (ret) {
229 ret = -EFAULT;
230 break;
231 }
232 ret = rtc_arm_set_time(ops, &tm);
233 break;
234
235 case RTC_EPOCH_SET:
236#ifndef rtc_epoch
237
238
239
240 if (arg < 1900) {
241 ret = -EINVAL;
242 break;
243 }
244 if (!capable(CAP_SYS_TIME)) {
245 ret = -EACCES;
246 break;
247 }
248 rtc_epoch = arg;
249 ret = 0;
250#endif
251 break;
252
253 case RTC_EPOCH_READ:
254 ret = put_user(rtc_epoch, (unsigned long __user *)uarg);
255 break;
256
257 case RTC_WKALM_SET:
258 ret = copy_from_user(&alrm, uarg, sizeof(alrm));
259 if (ret) {
260 ret = -EFAULT;
261 break;
262 }
263 ret = rtc_arm_set_alarm(ops, &alrm);
264 break;
265
266 case RTC_WKALM_RD:
267 ret = rtc_arm_read_alarm(ops, &alrm);
268 if (ret)
269 break;
270 ret = copy_to_user(uarg, &alrm, sizeof(alrm));
271 if (ret)
272 ret = -EFAULT;
273 break;
274
275 default:
276 if (ops->ioctl)
277 ret = ops->ioctl(cmd, arg);
278 break;
279 }
280 return ret;
281}
282
283static int rtc_open(struct inode *inode, struct file *file)
284{
285 int ret;
286
287 mutex_lock(&rtc_mutex);
288
289 if (rtc_inuse) {
290 ret = -EBUSY;
291 } else if (!rtc_ops || !try_module_get(rtc_ops->owner)) {
292 ret = -ENODEV;
293 } else {
294 file->private_data = rtc_ops;
295
296 ret = rtc_ops->open ? rtc_ops->open() : 0;
297 if (ret == 0) {
298 spin_lock_irq(&rtc_lock);
299 rtc_irq_data = 0;
300 spin_unlock_irq(&rtc_lock);
301
302 rtc_inuse = 1;
303 }
304 }
305 mutex_unlock(&rtc_mutex);
306
307 return ret;
308}
309
310static int rtc_release(struct inode *inode, struct file *file)
311{
312 struct rtc_ops *ops = file->private_data;
313
314 if (ops->release)
315 ops->release();
316
317 spin_lock_irq(&rtc_lock);
318 rtc_irq_data = 0;
319 spin_unlock_irq(&rtc_lock);
320
321 module_put(rtc_ops->owner);
322 rtc_inuse = 0;
323
324 return 0;
325}
326
327static int rtc_fasync(int fd, struct file *file, int on)
328{
329 return fasync_helper(fd, file, on, &rtc_async_queue);
330}
331
332static const struct file_operations rtc_fops = {
333 .owner = THIS_MODULE,
334 .llseek = no_llseek,
335 .read = rtc_read,
336 .poll = rtc_poll,
337 .ioctl = rtc_ioctl,
338 .open = rtc_open,
339 .release = rtc_release,
340 .fasync = rtc_fasync,
341};
342
343static struct miscdevice rtc_miscdev = {
344 .minor = RTC_MINOR,
345 .name = "rtc",
346 .fops = &rtc_fops,
347};
348
349
350static int rtc_read_proc(char *page, char **start, off_t off, int count, int *eof, void *data)
351{
352 struct rtc_ops *ops = data;
353 struct rtc_wkalrm alrm;
354 struct rtc_time tm;
355 char *p = page;
356
357 if (rtc_arm_read_time(ops, &tm) == 0) {
358 p += sprintf(p,
359 "rtc_time\t: %02d:%02d:%02d\n"
360 "rtc_date\t: %04d-%02d-%02d\n"
361 "rtc_epoch\t: %04lu\n",
362 tm.tm_hour, tm.tm_min, tm.tm_sec,
363 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
364 rtc_epoch);
365 }
366
367 if (rtc_arm_read_alarm(ops, &alrm) == 0) {
368 p += sprintf(p, "alrm_time\t: ");
369 if ((unsigned int)alrm.time.tm_hour <= 24)
370 p += sprintf(p, "%02d:", alrm.time.tm_hour);
371 else
372 p += sprintf(p, "**:");
373 if ((unsigned int)alrm.time.tm_min <= 59)
374 p += sprintf(p, "%02d:", alrm.time.tm_min);
375 else
376 p += sprintf(p, "**:");
377 if ((unsigned int)alrm.time.tm_sec <= 59)
378 p += sprintf(p, "%02d\n", alrm.time.tm_sec);
379 else
380 p += sprintf(p, "**\n");
381
382 p += sprintf(p, "alrm_date\t: ");
383 if ((unsigned int)alrm.time.tm_year <= 200)
384 p += sprintf(p, "%04d-", alrm.time.tm_year + 1900);
385 else
386 p += sprintf(p, "****-");
387 if ((unsigned int)alrm.time.tm_mon <= 11)
388 p += sprintf(p, "%02d-", alrm.time.tm_mon + 1);
389 else
390 p += sprintf(p, "**-");
391 if ((unsigned int)alrm.time.tm_mday <= 31)
392 p += sprintf(p, "%02d\n", alrm.time.tm_mday);
393 else
394 p += sprintf(p, "**\n");
395 p += sprintf(p, "alrm_wakeup\t: %s\n",
396 alrm.enabled ? "yes" : "no");
397 p += sprintf(p, "alrm_pending\t: %s\n",
398 alrm.pending ? "yes" : "no");
399 }
400
401 if (ops->proc)
402 p += ops->proc(p);
403
404 return p - page;
405}
406
407int register_rtc(struct rtc_ops *ops)
408{
409 int ret = -EBUSY;
410
411 mutex_lock(&rtc_mutex);
412 if (rtc_ops == NULL) {
413 rtc_ops = ops;
414
415 ret = misc_register(&rtc_miscdev);
416 if (ret == 0)
417 create_proc_read_entry("driver/rtc", 0, NULL,
418 rtc_read_proc, ops);
419 }
420 mutex_unlock(&rtc_mutex);
421
422 return ret;
423}
424EXPORT_SYMBOL(register_rtc);
425
426void unregister_rtc(struct rtc_ops *rtc)
427{
428 mutex_lock(&rtc_mutex);
429 if (rtc == rtc_ops) {
430 remove_proc_entry("driver/rtc", NULL);
431 misc_deregister(&rtc_miscdev);
432 rtc_ops = NULL;
433 }
434 mutex_unlock(&rtc_mutex);
435}
436EXPORT_SYMBOL(unregister_rtc);
437
