blob: 69f0a2993af0f7456b118bcaa0931e7730751067 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Real Time Clock interface for
3 * - q40 and other m68k machines,
4 * - HP PARISC machines
5 * - PowerPC machines
6 * emulate some RTC irq capabilities in software
7 *
8 * Copyright (C) 1999 Richard Zidlicky
9 *
10 * based on Paul Gortmaker's rtc.c device and
11 * Sam Creasey Generic rtc driver
12 *
13 * This driver allows use of the real time clock (built into
14 * nearly all computers) from user space. It exports the /dev/rtc
Robert P. J. Dayc685ce02007-05-09 07:21:11 +020015 * interface supporting various ioctl() and also the /proc/driver/rtc
Linus Torvalds1da177e2005-04-16 15:20:36 -070016 * pseudo-file for status information.
17 *
18 * The ioctls can be used to set the interrupt behaviour where
19 * supported.
20 *
21 * The /dev/rtc interface will block on reads until an interrupt
22 * has been received. If a RTC interrupt has already happened,
23 * it will output an unsigned long and then block. The output value
24 * contains the interrupt status in the low byte and the number of
25 * interrupts since the last read in the remaining high bytes. The
26 * /dev/rtc interface can also be used with the select(2) call.
27 *
28 * This program is free software; you can redistribute it and/or
29 * modify it under the terms of the GNU General Public License
30 * as published by the Free Software Foundation; either version
31 * 2 of the License, or (at your option) any later version.
32 *
33
34 * 1.01 fix for 2.3.X rz@linux-m68k.org
35 * 1.02 merged with code from genrtc.c rz@linux-m68k.org
36 * 1.03 make it more portable zippel@linux-m68k.org
37 * 1.04 removed useless timer code rz@linux-m68k.org
38 * 1.05 portable RTC_UIE emulation rz@linux-m68k.org
39 * 1.06 set_rtc_time can return an error trini@kernel.crashing.org
40 * 1.07 ported to HP PARISC (hppa) Helge Deller <deller@gmx.de>
41 */
42
43#define RTC_VERSION "1.07"
44
45#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070046#include <linux/errno.h>
47#include <linux/miscdevice.h>
48#include <linux/fcntl.h>
49
50#include <linux/rtc.h>
51#include <linux/init.h>
52#include <linux/poll.h>
53#include <linux/proc_fs.h>
54#include <linux/workqueue.h>
55
56#include <asm/uaccess.h>
57#include <asm/system.h>
58#include <asm/rtc.h>
59
60/*
61 * We sponge a minor off of the misc major. No need slurping
62 * up another valuable major dev number for this. If you add
63 * an ioctl, make sure you don't conflict with SPARC's RTC
64 * ioctls.
65 */
66
67static DECLARE_WAIT_QUEUE_HEAD(gen_rtc_wait);
68
69/*
70 * Bits in gen_rtc_status.
71 */
72
73#define RTC_IS_OPEN 0x01 /* means /dev/rtc is in use */
74
75static unsigned char gen_rtc_status; /* bitmapped status byte. */
76static unsigned long gen_rtc_irq_data; /* our output to the world */
77
78/* months start at 0 now */
79static unsigned char days_in_mo[] =
80{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
81
82static int irq_active;
83
84#ifdef CONFIG_GEN_RTC_X
85static struct work_struct genrtc_task;
86static struct timer_list timer_task;
87
88static unsigned int oldsecs;
89static int lostint;
90static unsigned long tt_exp;
91
92static void gen_rtc_timer(unsigned long data);
93
94static volatile int stask_active; /* schedule_work */
95static volatile int ttask_active; /* timer_task */
96static int stop_rtc_timers; /* don't requeue tasks */
97static DEFINE_SPINLOCK(gen_rtc_lock);
98
99static void gen_rtc_interrupt(unsigned long arg);
100
101/*
102 * Routine to poll RTC seconds field for change as often as possible,
103 * after first RTC_UIE use timer to reduce polling
104 */
David Howellsc4028952006-11-22 14:57:56 +0000105static void genrtc_troutine(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106{
107 unsigned int tmp = get_rtc_ss();
108
109 if (stop_rtc_timers) {
110 stask_active = 0;
111 return;
112 }
113
114 if (oldsecs != tmp){
115 oldsecs = tmp;
116
117 timer_task.function = gen_rtc_timer;
118 timer_task.expires = jiffies + HZ - (HZ/10);
119 tt_exp=timer_task.expires;
120 ttask_active=1;
121 stask_active=0;
122 add_timer(&timer_task);
123
124 gen_rtc_interrupt(0);
125 } else if (schedule_work(&genrtc_task) == 0)
126 stask_active = 0;
127}
128
129static void gen_rtc_timer(unsigned long data)
130{
131 lostint = get_rtc_ss() - oldsecs ;
132 if (lostint<0)
133 lostint = 60 - lostint;
134 if (time_after(jiffies, tt_exp))
135 printk(KERN_INFO "genrtc: timer task delayed by %ld jiffies\n",
136 jiffies-tt_exp);
137 ttask_active=0;
138 stask_active=1;
139 if ((schedule_work(&genrtc_task) == 0))
140 stask_active = 0;
141}
142
143/*
144 * call gen_rtc_interrupt function to signal an RTC_UIE,
145 * arg is unused.
146 * Could be invoked either from a real interrupt handler or
147 * from some routine that periodically (eg 100HZ) monitors
148 * whether RTC_SECS changed
149 */
150static void gen_rtc_interrupt(unsigned long arg)
151{
152 /* We store the status in the low byte and the number of
153 * interrupts received since the last read in the remainder
154 * of rtc_irq_data. */
155
156 gen_rtc_irq_data += 0x100;
157 gen_rtc_irq_data &= ~0xff;
158 gen_rtc_irq_data |= RTC_UIE;
159
160 if (lostint){
161 printk("genrtc: system delaying clock ticks?\n");
162 /* increment count so that userspace knows something is wrong */
163 gen_rtc_irq_data += ((lostint-1)<<8);
164 lostint = 0;
165 }
166
167 wake_up_interruptible(&gen_rtc_wait);
168}
169
170/*
171 * Now all the various file operations that we export.
172 */
173static ssize_t gen_rtc_read(struct file *file, char __user *buf,
174 size_t count, loff_t *ppos)
175{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 unsigned long data;
177 ssize_t retval;
178
179 if (count != sizeof (unsigned int) && count != sizeof (unsigned long))
180 return -EINVAL;
181
182 if (file->f_flags & O_NONBLOCK && !gen_rtc_irq_data)
183 return -EAGAIN;
184
Jiri Slabye0955e12007-07-15 23:40:19 -0700185 retval = wait_event_interruptible(gen_rtc_wait,
186 (data = xchg(&gen_rtc_irq_data, 0)));
187 if (retval)
188 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189
190 /* first test allows optimizer to nuke this case for 32-bit machines */
191 if (sizeof (int) != sizeof (long) && count == sizeof (unsigned int)) {
192 unsigned int uidata = data;
Atsushi Nemotof3537ea2006-05-01 12:16:17 -0700193 retval = put_user(uidata, (unsigned int __user *)buf) ?:
194 sizeof(unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 }
196 else {
Atsushi Nemotof3537ea2006-05-01 12:16:17 -0700197 retval = put_user(data, (unsigned long __user *)buf) ?:
198 sizeof(unsigned long);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 }
Jiri Slabye0955e12007-07-15 23:40:19 -0700200out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 return retval;
202}
203
204static unsigned int gen_rtc_poll(struct file *file,
205 struct poll_table_struct *wait)
206{
207 poll_wait(file, &gen_rtc_wait, wait);
208 if (gen_rtc_irq_data != 0)
209 return POLLIN | POLLRDNORM;
210 return 0;
211}
212
213#endif
214
215/*
216 * Used to disable/enable interrupts, only RTC_UIE supported
217 * We also clear out any old irq data after an ioctl() that
218 * meddles with the interrupt enable/disable bits.
219 */
220
221static inline void gen_clear_rtc_irq_bit(unsigned char bit)
222{
223#ifdef CONFIG_GEN_RTC_X
224 stop_rtc_timers = 1;
225 if (ttask_active){
226 del_timer_sync(&timer_task);
227 ttask_active = 0;
228 }
229 while (stask_active)
230 schedule();
231
232 spin_lock(&gen_rtc_lock);
233 irq_active = 0;
234 spin_unlock(&gen_rtc_lock);
235#endif
236}
237
238static inline int gen_set_rtc_irq_bit(unsigned char bit)
239{
240#ifdef CONFIG_GEN_RTC_X
241 spin_lock(&gen_rtc_lock);
242 if ( !irq_active ) {
243 irq_active = 1;
244 stop_rtc_timers = 0;
245 lostint = 0;
David Howellsc4028952006-11-22 14:57:56 +0000246 INIT_WORK(&genrtc_task, genrtc_troutine);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 oldsecs = get_rtc_ss();
248 init_timer(&timer_task);
249
250 stask_active = 1;
251 if (schedule_work(&genrtc_task) == 0){
252 stask_active = 0;
253 }
254 }
255 spin_unlock(&gen_rtc_lock);
256 gen_rtc_irq_data = 0;
257 return 0;
258#else
259 return -EINVAL;
260#endif
261}
262
263static int gen_rtc_ioctl(struct inode *inode, struct file *file,
264 unsigned int cmd, unsigned long arg)
265{
266 struct rtc_time wtime;
267 struct rtc_pll_info pll;
268 void __user *argp = (void __user *)arg;
269
270 switch (cmd) {
271
272 case RTC_PLL_GET:
273 if (get_rtc_pll(&pll))
274 return -EINVAL;
275 else
276 return copy_to_user(argp, &pll, sizeof pll) ? -EFAULT : 0;
277
278 case RTC_PLL_SET:
279 if (!capable(CAP_SYS_TIME))
280 return -EACCES;
281 if (copy_from_user(&pll, argp, sizeof(pll)))
282 return -EFAULT;
283 return set_rtc_pll(&pll);
284
285 case RTC_UIE_OFF: /* disable ints from RTC updates. */
286 gen_clear_rtc_irq_bit(RTC_UIE);
287 return 0;
288
289 case RTC_UIE_ON: /* enable ints for RTC updates. */
290 return gen_set_rtc_irq_bit(RTC_UIE);
291
292 case RTC_RD_TIME: /* Read the time/date from RTC */
293 /* this doesn't get week-day, who cares */
294 memset(&wtime, 0, sizeof(wtime));
295 get_rtc_time(&wtime);
296
297 return copy_to_user(argp, &wtime, sizeof(wtime)) ? -EFAULT : 0;
298
299 case RTC_SET_TIME: /* Set the RTC */
300 {
301 int year;
302 unsigned char leap_yr;
303
304 if (!capable(CAP_SYS_TIME))
305 return -EACCES;
306
307 if (copy_from_user(&wtime, argp, sizeof(wtime)))
308 return -EFAULT;
309
310 year = wtime.tm_year + 1900;
311 leap_yr = ((!(year % 4) && (year % 100)) ||
312 !(year % 400));
313
314 if ((wtime.tm_mon < 0 || wtime.tm_mon > 11) || (wtime.tm_mday < 1))
315 return -EINVAL;
316
317 if (wtime.tm_mday < 0 || wtime.tm_mday >
318 (days_in_mo[wtime.tm_mon] + ((wtime.tm_mon == 1) && leap_yr)))
319 return -EINVAL;
320
321 if (wtime.tm_hour < 0 || wtime.tm_hour >= 24 ||
322 wtime.tm_min < 0 || wtime.tm_min >= 60 ||
323 wtime.tm_sec < 0 || wtime.tm_sec >= 60)
324 return -EINVAL;
325
326 return set_rtc_time(&wtime);
327 }
328 }
329
330 return -EINVAL;
331}
332
333/*
334 * We enforce only one user at a time here with the open/close.
335 * Also clear the previous interrupt data on an open, and clean
336 * up things on a close.
337 */
338
339static int gen_rtc_open(struct inode *inode, struct file *file)
340{
341 if (gen_rtc_status & RTC_IS_OPEN)
342 return -EBUSY;
343
344 gen_rtc_status |= RTC_IS_OPEN;
345 gen_rtc_irq_data = 0;
346 irq_active = 0;
347
348 return 0;
349}
350
351static int gen_rtc_release(struct inode *inode, struct file *file)
352{
353 /*
354 * Turn off all interrupts once the device is no longer
355 * in use and clear the data.
356 */
357
358 gen_clear_rtc_irq_bit(RTC_PIE|RTC_AIE|RTC_UIE);
359
360 gen_rtc_status &= ~RTC_IS_OPEN;
361 return 0;
362}
363
364
365#ifdef CONFIG_PROC_FS
366
367/*
Robert P. J. Dayc685ce02007-05-09 07:21:11 +0200368 * Info exported via "/proc/driver/rtc".
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369 */
370
371static int gen_rtc_proc_output(char *buf)
372{
373 char *p;
374 struct rtc_time tm;
375 unsigned int flags;
376 struct rtc_pll_info pll;
377
378 p = buf;
379
380 flags = get_rtc_time(&tm);
381
382 p += sprintf(p,
383 "rtc_time\t: %02d:%02d:%02d\n"
384 "rtc_date\t: %04d-%02d-%02d\n"
385 "rtc_epoch\t: %04u\n",
386 tm.tm_hour, tm.tm_min, tm.tm_sec,
387 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, 1900);
388
389 tm.tm_hour = tm.tm_min = tm.tm_sec = 0;
390
391 p += sprintf(p, "alarm\t\t: ");
392 if (tm.tm_hour <= 24)
393 p += sprintf(p, "%02d:", tm.tm_hour);
394 else
395 p += sprintf(p, "**:");
396
397 if (tm.tm_min <= 59)
398 p += sprintf(p, "%02d:", tm.tm_min);
399 else
400 p += sprintf(p, "**:");
401
402 if (tm.tm_sec <= 59)
403 p += sprintf(p, "%02d\n", tm.tm_sec);
404 else
405 p += sprintf(p, "**\n");
406
407 p += sprintf(p,
408 "DST_enable\t: %s\n"
409 "BCD\t\t: %s\n"
410 "24hr\t\t: %s\n"
411 "square_wave\t: %s\n"
412 "alarm_IRQ\t: %s\n"
413 "update_IRQ\t: %s\n"
414 "periodic_IRQ\t: %s\n"
415 "periodic_freq\t: %ld\n"
416 "batt_status\t: %s\n",
417 (flags & RTC_DST_EN) ? "yes" : "no",
418 (flags & RTC_DM_BINARY) ? "no" : "yes",
419 (flags & RTC_24H) ? "yes" : "no",
420 (flags & RTC_SQWE) ? "yes" : "no",
421 (flags & RTC_AIE) ? "yes" : "no",
422 irq_active ? "yes" : "no",
423 (flags & RTC_PIE) ? "yes" : "no",
424 0L /* freq */,
425 (flags & RTC_BATT_BAD) ? "bad" : "okay");
426 if (!get_rtc_pll(&pll))
427 p += sprintf(p,
428 "PLL adjustment\t: %d\n"
429 "PLL max +ve adjustment\t: %d\n"
430 "PLL max -ve adjustment\t: %d\n"
431 "PLL +ve adjustment factor\t: %d\n"
432 "PLL -ve adjustment factor\t: %d\n"
433 "PLL frequency\t: %ld\n",
434 pll.pll_value,
435 pll.pll_max,
436 pll.pll_min,
437 pll.pll_posmult,
438 pll.pll_negmult,
439 pll.pll_clock);
440 return p - buf;
441}
442
443static int gen_rtc_read_proc(char *page, char **start, off_t off,
444 int count, int *eof, void *data)
445{
446 int len = gen_rtc_proc_output (page);
447 if (len <= off+count) *eof = 1;
448 *start = page + off;
449 len -= off;
450 if (len>count) len = count;
451 if (len<0) len = 0;
452 return len;
453}
454
455static int __init gen_rtc_proc_init(void)
456{
457 struct proc_dir_entry *r;
458
459 r = create_proc_read_entry("driver/rtc", 0, NULL, gen_rtc_read_proc, NULL);
460 if (!r)
461 return -ENOMEM;
462 return 0;
463}
464#else
465static inline int gen_rtc_proc_init(void) { return 0; }
466#endif /* CONFIG_PROC_FS */
467
468
469/*
470 * The various file operations we support.
471 */
472
Arjan van de Ven62322d22006-07-03 00:24:21 -0700473static const struct file_operations gen_rtc_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 .owner = THIS_MODULE,
475#ifdef CONFIG_GEN_RTC_X
476 .read = gen_rtc_read,
477 .poll = gen_rtc_poll,
478#endif
479 .ioctl = gen_rtc_ioctl,
480 .open = gen_rtc_open,
481 .release = gen_rtc_release,
482};
483
484static struct miscdevice rtc_gen_dev =
485{
486 .minor = RTC_MINOR,
487 .name = "rtc",
488 .fops = &gen_rtc_fops,
489};
490
491static int __init rtc_generic_init(void)
492{
493 int retval;
494
495 printk(KERN_INFO "Generic RTC Driver v%s\n", RTC_VERSION);
496
497 retval = misc_register(&rtc_gen_dev);
498 if (retval < 0)
499 return retval;
500
501 retval = gen_rtc_proc_init();
502 if (retval) {
503 misc_deregister(&rtc_gen_dev);
504 return retval;
505 }
506
507 return 0;
508}
509
510static void __exit rtc_generic_exit(void)
511{
512 remove_proc_entry ("driver/rtc", NULL);
513 misc_deregister(&rtc_gen_dev);
514}
515
516
517module_init(rtc_generic_init);
518module_exit(rtc_generic_exit);
519
520MODULE_AUTHOR("Richard Zidlicky");
521MODULE_LICENSE("GPL");
522MODULE_ALIAS_MISCDEV(RTC_MINOR);