aboutsummaryrefslogtreecommitdiff
path: root/arch/arm/common/rtctime.c
blob: aa8f7739c822c5efa1a850beda94bbd4ea8b971a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
/*
 *  linux/arch/arm/common/rtctime.c
 *
 *  Copyright (C) 2003 Deep Blue Solutions Ltd.
 *  Based on sa1100-rtc.c, Nils Faerber, CIH, Nicolas Pitre.
 *  Based on rtc.c by Paul Gortmaker
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/time.h>
#include <linux/rtc.h>
#include <linux/poll.h>
#include <linux/proc_fs.h>
#include <linux/miscdevice.h>
#include <linux/spinlock.h>
#include <linux/capability.h>
#include <linux/device.h>
#include <linux/mutex.h>

#include <asm/rtc.h>

static DECLARE_WAIT_QUEUE_HEAD(rtc_wait);
static struct fasync_struct *rtc_async_queue;

/*
 * rtc_lock protects rtc_irq_data
 */
static DEFINE_SPINLOCK(rtc_lock);
static unsigned long rtc_irq_data;

/*
 * rtc_sem protects rtc_inuse and rtc_ops
 */
static DEFINE_MUTEX(rtc_mutex);
static unsigned long rtc_inuse;
static struct rtc_ops *rtc_ops;

#define rtc_epoch 1900UL

/*
 * Calculate the next alarm time given the requested alarm time mask
 * and the current time.
 */
void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now, struct rtc_time *alrm)
{
	unsigned long next_time;
	unsigned long now_time;

	next->tm_year = now->tm_year;
	next->tm_mon = now->tm_mon;
	next->tm_mday = now->tm_mday;
	next->tm_hour = alrm->tm_hour;
	next->tm_min = alrm->tm_min;
	next->tm_sec = alrm->tm_sec;

	rtc_tm_to_time(now, &now_time);
	rtc_tm_to_time(next, &next_time);

	if (next_time < now_time) {
		/* Advance one day */
		next_time += 60 * 60 * 24;
		rtc_time_to_tm(next_time, next);
	}
}
EXPORT_SYMBOL(rtc_next_alarm_time);

static inline int rtc_arm_read_time(struct rtc_ops *ops, struct rtc_time *tm)
{
	memset(tm, 0, sizeof(struct rtc_time));
	return ops->read_time(tm);
}

static inline int rtc_arm_set_time(struct rtc_ops *ops, struct rtc_time *tm)
{
	int ret;

	ret = rtc_valid_tm(tm);
	if (ret == 0)
		ret = ops->set_time(tm);

	return ret;
}

static inline int rtc_arm_read_alarm(struct rtc_ops *ops, struct rtc_wkalrm *alrm)
{
	int ret = -EINVAL;
	if (ops->read_alarm) {
		memset(alrm, 0, sizeof(struct rtc_wkalrm));
		ret = ops->read_alarm(alrm);
	}
	return ret;
}

static inline int rtc_arm_set_alarm(struct rtc_ops *ops, struct rtc_wkalrm *alrm)
{
	int ret = -EINVAL;
	if (ops->set_alarm)
		ret = ops->set_alarm(alrm);
	return ret;
}

void rtc_update(unsigned long num, unsigned long events)
{
	spin_lock(&rtc_lock);
	rtc_irq_data = (rtc_irq_data + (num << 8)) | events;
	spin_unlock(&rtc_lock);

	wake_up_interruptible(&rtc_wait);
	kill_fasync(&rtc_async_queue, SIGIO, POLL_IN);
}
EXPORT_SYMBOL(rtc_update);


static ssize_t
rtc_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{
	DECLARE_WAITQUEUE(wait, current);
	unsigned long data;
	ssize_t ret;

	if (count < sizeof(unsigned long))
		return -EINVAL;

	add_wait_queue(&rtc_wait, &wait);
	do {
		__set_current_state(TASK_INTERRUPTIBLE);

		spin_lock_irq(&rtc_lock);
		data = rtc_irq_data;
		rtc_irq_data = 0;
		spin_unlock_irq(&rtc_lock);

		if (data != 0) {
			ret = 0;
			break;
		}
		if (file->f_flags & O_NONBLOCK) {
			ret = -EAGAIN;
			break;
		}
		if (signal_pending(current)) {
			ret = -ERESTARTSYS;
			break;
		}
		schedule();
	} while (1);
	set_current_state(TASK_RUNNING);
	remove_wait_queue(&rtc_wait, &wait);

	if (ret == 0) {
		ret = put_user(data, (unsigned long __user *)buf);
		if (ret == 0)
			ret = sizeof(unsigned long);
	}
	return ret;
}

static unsigned int rtc_poll(struct file *file, poll_table *wait)
{
	unsigned long data;

	poll_wait(file, &rtc_wait, wait);

	spin_lock_irq(&rtc_lock);
	data = rtc_irq_data;
	spin_unlock_irq(&rtc_lock);

	return data != 0 ? POLLIN | POLLRDNORM : 0;
}

static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
		     unsigned long arg)
{
	struct rtc_ops *ops = file->private_data;
	struct rtc_time tm;
	struct rtc_wkalrm alrm;
	void __user *uarg = (void __user *)arg;
	int ret = -EINVAL;

	switch (cmd) {
	case RTC_ALM_READ:
		ret = rtc_arm_read_alarm(ops, &alrm);
		if (ret)
			break;
		ret = copy_to_user(uarg, &alrm.time, sizeof(tm));
		if (ret)
			ret = -EFAULT;
		break;

	case RTC_ALM_SET:
		ret = copy_from_user(&alrm.time, uarg, sizeof(tm));
		if (ret) {
			ret = -EFAULT;
			break;
		}
		alrm.enabled = 0;
		alrm.pending = 0;
		alrm.time.tm_mday = -1;
		alrm.time.tm_mon = -1;
		alrm.time.tm_year = -1;
		alrm.time.tm_wday = -1;
		alrm.time.tm_yday = -1;
		alrm.time.tm_isdst = -1;
		ret = rtc_arm_set_alarm(ops, &alrm);
		break;

	case RTC_RD_TIME:
		ret = rtc_arm_read_time(ops, &tm);
		if (ret)
			break;
		ret = copy_to_user(uarg, &tm, sizeof(tm));
		if (ret)
			ret = -EFAULT;
		break;

	case RTC_SET_TIME:
		if (!capable(CAP_SYS_TIME)) {
			ret = -EACCES;
			break;
		}
		ret = copy_from_user(&tm, uarg, sizeof(tm));
		if (ret) {
			ret = -EFAULT;
			break;
		}
		ret = rtc_arm_set_time(ops, &tm);
		break;

	case RTC_EPOCH_SET:
#ifndef rtc_epoch
		/*
		 * There were no RTC clocks before 1900.
		 */
		if (arg < 1900) {
			ret = -EINVAL;
			break;
		}
		if (!capable(CAP_SYS_TIME)) {
			ret = -EACCES;
			break;
		}
		rtc_epoch = arg;
		ret = 0;
#endif
		break;

	case RTC_EPOCH_READ:
		ret = put_user(rtc_epoch, (unsigned long __user *)uarg);
		break;

	case RTC_WKALM_SET:
		ret = copy_from_user(&alrm, uarg, sizeof(alrm));
		if (ret) {
			ret = -EFAULT;
			break;
		}
		ret = rtc_arm_set_alarm(ops, &alrm);
		break;

	case RTC_WKALM_RD:
		ret = rtc_arm_read_alarm(ops, &alrm);
		if (ret)
			break;
		ret = copy_to_user(uarg, &alrm, sizeof(alrm));
		if (ret)
			ret = -EFAULT;
		break;

	default:
		if (ops->ioctl)
			ret = ops->ioctl(cmd, arg);
		break;
	}
	return ret;
}

static int rtc_open(struct inode *inode, struct file *file)
{
	int ret;

	mutex_lock(&rtc_mutex);

	if (rtc_inuse) {
		ret = -EBUSY;
	} else if (!rtc_ops || !try_module_get(rtc_ops->owner)) {
		ret = -ENODEV;
	} else {
		file->private_data = rtc_ops;

		ret = rtc_ops->open ? rtc_ops->open() : 0;
		if (ret == 0) {
			spin_lock_irq(&rtc_lock);
			rtc_irq_data = 0;
			spin_unlock_irq(&rtc_lock);

			rtc_inuse = 1;
		}
	}
	mutex_unlock(&rtc_mutex);

	return ret;
}

static int rtc_release(struct inode *inode, struct file *file)
{
	struct rtc_ops *ops = file->private_data;

	if (ops->release)
		ops->release();

	spin_lock_irq(&rtc_lock);
	rtc_irq_data = 0;
	spin_unlock_irq(&rtc_lock);

	module_put(rtc_ops->owner);
	rtc_inuse = 0;

	return 0;
}

static int rtc_fasync(int fd, struct file *file, int on)
{
	return fasync_helper(fd, file, on, &rtc_async_queue);
}

static const struct file_operations rtc_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.read		= rtc_read,
	.poll		= rtc_poll,
	.ioctl		= rtc_ioctl,
	.open		= rtc_open,
	.release	= rtc_release,
	.fasync		= rtc_fasync,
};

static struct miscdevice rtc_miscdev = {
	.minor		= RTC_MINOR,
	.name		= "rtc",
	.fops		= &rtc_fops,
};


static int rtc_read_proc(char *page, char **start, off_t off, int count, int *eof, void *data)
{
	struct rtc_ops *ops = data;
	struct rtc_wkalrm alrm;
	struct rtc_time tm;
	char *p = page;

	if (rtc_arm_read_time(ops, &tm) == 0) {
		p += sprintf(p,
			"rtc_time\t: %02d:%02d:%02d\n"
			"rtc_date\t: %04d-%02d-%02d\n"
			"rtc_epoch\t: %04lu\n",
			tm.tm_hour, tm.tm_min, tm.tm_sec,
			tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
			rtc_epoch);
	}

	if (rtc_arm_read_alarm(ops, &alrm) == 0) {
		p += sprintf(p, "alrm_time\t: ");
		if ((unsigned int)alrm.time.tm_hour <= 24)
			p += sprintf(p, "%02d:", alrm.time.tm_hour);
		else
			p += sprintf(p, "**:");
		if ((unsigned int)alrm.time.tm_min <= 59)
			p += sprintf(p, "%02d:", alrm.time.tm_min);
		else
			p += sprintf(p, "**:");
		if ((unsigned int)alrm.time.tm_sec <= 59)
			p += sprintf(p, "%02d\n", alrm.time.tm_sec);
		else
			p += sprintf(p, "**\n");

		p += sprintf(p, "alrm_date\t: ");
		if ((unsigned int)alrm.time.tm_year <= 200)
			p += sprintf(p, "%04d-", alrm.time.tm_year + 1900);
		else
			p += sprintf(p, "****-");
		if ((unsigned int)alrm.time.tm_mon <= 11)
			p += sprintf(p, "%02d-", alrm.time.tm_mon + 1);
		else
			p += sprintf(p, "**-");
		if ((unsigned int)alrm.time.tm_mday <= 31)
			p += sprintf(p, "%02d\n", alrm.time.tm_mday);
		else
			p += sprintf(p, "**\n");
		p += sprintf(p, "alrm_wakeup\t: %s\n",
			     alrm.enabled ? "yes" : "no");
		p += sprintf(p, "alrm_pending\t: %s\n",
			     alrm.pending ? "yes" : "no");
	}

	if (ops->proc)
		p += ops->proc(p);

	return p - page;
}

int register_rtc(struct rtc_ops *ops)
{
	int ret = -EBUSY;

	mutex_lock(&rtc_mutex);
	if (rtc_ops == NULL) {
		rtc_ops = ops;

		ret = misc_register(&rtc_miscdev);
		if (ret == 0)
			create_proc_read_entry("driver/rtc", 0, NULL,
					       rtc_read_proc, ops);
	}
	mutex_unlock(&rtc_mutex);

	return ret;
}
EXPORT_SYMBOL(register_rtc);

void unregister_rtc(struct rtc_ops *rtc)
{
	mutex_lock(&rtc_mutex);
	if (rtc == rtc_ops) {
		remove_proc_entry("driver/rtc", NULL);
		misc_deregister(&rtc_miscdev);
		rtc_ops = NULL;
	}
	mutex_unlock(&rtc_mutex);
}
EXPORT_SYMBOL(unregister_rtc);