Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
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 | |
c685ce05 | 15 | * interface supporting various ioctl() and also the /proc/driver/rtc |
1da177e4 LT |
16 | * 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> | |
86ae13b0 | 46 | #include <linux/sched.h> |
1da177e4 LT |
47 | #include <linux/errno.h> |
48 | #include <linux/miscdevice.h> | |
49 | #include <linux/fcntl.h> | |
50 | ||
51 | #include <linux/rtc.h> | |
52 | #include <linux/init.h> | |
53 | #include <linux/poll.h> | |
54 | #include <linux/proc_fs.h> | |
613655fa | 55 | #include <linux/mutex.h> |
1da177e4 LT |
56 | #include <linux/workqueue.h> |
57 | ||
58 | #include <asm/uaccess.h> | |
1da177e4 LT |
59 | #include <asm/rtc.h> |
60 | ||
61 | /* | |
62 | * We sponge a minor off of the misc major. No need slurping | |
63 | * up another valuable major dev number for this. If you add | |
64 | * an ioctl, make sure you don't conflict with SPARC's RTC | |
65 | * ioctls. | |
66 | */ | |
67 | ||
613655fa | 68 | static DEFINE_MUTEX(gen_rtc_mutex); |
1da177e4 LT |
69 | static DECLARE_WAIT_QUEUE_HEAD(gen_rtc_wait); |
70 | ||
71 | /* | |
72 | * Bits in gen_rtc_status. | |
73 | */ | |
74 | ||
75 | #define RTC_IS_OPEN 0x01 /* means /dev/rtc is in use */ | |
76 | ||
77 | static unsigned char gen_rtc_status; /* bitmapped status byte. */ | |
78 | static unsigned long gen_rtc_irq_data; /* our output to the world */ | |
79 | ||
80 | /* months start at 0 now */ | |
81 | static unsigned char days_in_mo[] = | |
82 | {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; | |
83 | ||
84 | static int irq_active; | |
85 | ||
86 | #ifdef CONFIG_GEN_RTC_X | |
87 | static struct work_struct genrtc_task; | |
88 | static struct timer_list timer_task; | |
89 | ||
90 | static unsigned int oldsecs; | |
91 | static int lostint; | |
92 | static unsigned long tt_exp; | |
93 | ||
94 | static void gen_rtc_timer(unsigned long data); | |
95 | ||
96 | static volatile int stask_active; /* schedule_work */ | |
97 | static volatile int ttask_active; /* timer_task */ | |
98 | static int stop_rtc_timers; /* don't requeue tasks */ | |
99 | static DEFINE_SPINLOCK(gen_rtc_lock); | |
100 | ||
101 | static void gen_rtc_interrupt(unsigned long arg); | |
102 | ||
103 | /* | |
104 | * Routine to poll RTC seconds field for change as often as possible, | |
105 | * after first RTC_UIE use timer to reduce polling | |
106 | */ | |
c4028958 | 107 | static void genrtc_troutine(struct work_struct *work) |
1da177e4 LT |
108 | { |
109 | unsigned int tmp = get_rtc_ss(); | |
110 | ||
111 | if (stop_rtc_timers) { | |
112 | stask_active = 0; | |
113 | return; | |
114 | } | |
115 | ||
116 | if (oldsecs != tmp){ | |
117 | oldsecs = tmp; | |
118 | ||
119 | timer_task.function = gen_rtc_timer; | |
120 | timer_task.expires = jiffies + HZ - (HZ/10); | |
121 | tt_exp=timer_task.expires; | |
122 | ttask_active=1; | |
123 | stask_active=0; | |
124 | add_timer(&timer_task); | |
125 | ||
126 | gen_rtc_interrupt(0); | |
127 | } else if (schedule_work(&genrtc_task) == 0) | |
128 | stask_active = 0; | |
129 | } | |
130 | ||
131 | static void gen_rtc_timer(unsigned long data) | |
132 | { | |
133 | lostint = get_rtc_ss() - oldsecs ; | |
134 | if (lostint<0) | |
135 | lostint = 60 - lostint; | |
136 | if (time_after(jiffies, tt_exp)) | |
137 | printk(KERN_INFO "genrtc: timer task delayed by %ld jiffies\n", | |
138 | jiffies-tt_exp); | |
139 | ttask_active=0; | |
140 | stask_active=1; | |
141 | if ((schedule_work(&genrtc_task) == 0)) | |
142 | stask_active = 0; | |
143 | } | |
144 | ||
145 | /* | |
146 | * call gen_rtc_interrupt function to signal an RTC_UIE, | |
147 | * arg is unused. | |
148 | * Could be invoked either from a real interrupt handler or | |
149 | * from some routine that periodically (eg 100HZ) monitors | |
150 | * whether RTC_SECS changed | |
151 | */ | |
152 | static void gen_rtc_interrupt(unsigned long arg) | |
153 | { | |
154 | /* We store the status in the low byte and the number of | |
155 | * interrupts received since the last read in the remainder | |
156 | * of rtc_irq_data. */ | |
157 | ||
158 | gen_rtc_irq_data += 0x100; | |
159 | gen_rtc_irq_data &= ~0xff; | |
160 | gen_rtc_irq_data |= RTC_UIE; | |
161 | ||
162 | if (lostint){ | |
163 | printk("genrtc: system delaying clock ticks?\n"); | |
164 | /* increment count so that userspace knows something is wrong */ | |
165 | gen_rtc_irq_data += ((lostint-1)<<8); | |
166 | lostint = 0; | |
167 | } | |
168 | ||
169 | wake_up_interruptible(&gen_rtc_wait); | |
170 | } | |
171 | ||
172 | /* | |
173 | * Now all the various file operations that we export. | |
174 | */ | |
175 | static ssize_t gen_rtc_read(struct file *file, char __user *buf, | |
176 | size_t count, loff_t *ppos) | |
177 | { | |
1da177e4 LT |
178 | unsigned long data; |
179 | ssize_t retval; | |
180 | ||
181 | if (count != sizeof (unsigned int) && count != sizeof (unsigned long)) | |
182 | return -EINVAL; | |
183 | ||
184 | if (file->f_flags & O_NONBLOCK && !gen_rtc_irq_data) | |
185 | return -EAGAIN; | |
186 | ||
e0955e14 JS |
187 | retval = wait_event_interruptible(gen_rtc_wait, |
188 | (data = xchg(&gen_rtc_irq_data, 0))); | |
189 | if (retval) | |
190 | goto out; | |
1da177e4 LT |
191 | |
192 | /* first test allows optimizer to nuke this case for 32-bit machines */ | |
193 | if (sizeof (int) != sizeof (long) && count == sizeof (unsigned int)) { | |
194 | unsigned int uidata = data; | |
f3537ea7 AN |
195 | retval = put_user(uidata, (unsigned int __user *)buf) ?: |
196 | sizeof(unsigned int); | |
1da177e4 LT |
197 | } |
198 | else { | |
f3537ea7 AN |
199 | retval = put_user(data, (unsigned long __user *)buf) ?: |
200 | sizeof(unsigned long); | |
1da177e4 | 201 | } |
e0955e14 | 202 | out: |
1da177e4 LT |
203 | return retval; |
204 | } | |
205 | ||
206 | static unsigned int gen_rtc_poll(struct file *file, | |
207 | struct poll_table_struct *wait) | |
208 | { | |
209 | poll_wait(file, &gen_rtc_wait, wait); | |
210 | if (gen_rtc_irq_data != 0) | |
211 | return POLLIN | POLLRDNORM; | |
212 | return 0; | |
213 | } | |
214 | ||
215 | #endif | |
216 | ||
217 | /* | |
218 | * Used to disable/enable interrupts, only RTC_UIE supported | |
219 | * We also clear out any old irq data after an ioctl() that | |
220 | * meddles with the interrupt enable/disable bits. | |
221 | */ | |
222 | ||
223 | static inline void gen_clear_rtc_irq_bit(unsigned char bit) | |
224 | { | |
225 | #ifdef CONFIG_GEN_RTC_X | |
226 | stop_rtc_timers = 1; | |
227 | if (ttask_active){ | |
228 | del_timer_sync(&timer_task); | |
229 | ttask_active = 0; | |
230 | } | |
231 | while (stask_active) | |
232 | schedule(); | |
233 | ||
234 | spin_lock(&gen_rtc_lock); | |
235 | irq_active = 0; | |
236 | spin_unlock(&gen_rtc_lock); | |
237 | #endif | |
238 | } | |
239 | ||
240 | static inline int gen_set_rtc_irq_bit(unsigned char bit) | |
241 | { | |
242 | #ifdef CONFIG_GEN_RTC_X | |
243 | spin_lock(&gen_rtc_lock); | |
244 | if ( !irq_active ) { | |
245 | irq_active = 1; | |
246 | stop_rtc_timers = 0; | |
247 | lostint = 0; | |
c4028958 | 248 | INIT_WORK(&genrtc_task, genrtc_troutine); |
1da177e4 LT |
249 | oldsecs = get_rtc_ss(); |
250 | init_timer(&timer_task); | |
251 | ||
252 | stask_active = 1; | |
253 | if (schedule_work(&genrtc_task) == 0){ | |
254 | stask_active = 0; | |
255 | } | |
256 | } | |
257 | spin_unlock(&gen_rtc_lock); | |
258 | gen_rtc_irq_data = 0; | |
259 | return 0; | |
260 | #else | |
261 | return -EINVAL; | |
262 | #endif | |
263 | } | |
264 | ||
55929332 | 265 | static int gen_rtc_ioctl(struct file *file, |
1da177e4 LT |
266 | unsigned int cmd, unsigned long arg) |
267 | { | |
268 | struct rtc_time wtime; | |
269 | struct rtc_pll_info pll; | |
270 | void __user *argp = (void __user *)arg; | |
271 | ||
272 | switch (cmd) { | |
273 | ||
274 | case RTC_PLL_GET: | |
275 | if (get_rtc_pll(&pll)) | |
276 | return -EINVAL; | |
277 | else | |
278 | return copy_to_user(argp, &pll, sizeof pll) ? -EFAULT : 0; | |
279 | ||
280 | case RTC_PLL_SET: | |
281 | if (!capable(CAP_SYS_TIME)) | |
282 | return -EACCES; | |
283 | if (copy_from_user(&pll, argp, sizeof(pll))) | |
284 | return -EFAULT; | |
285 | return set_rtc_pll(&pll); | |
286 | ||
287 | case RTC_UIE_OFF: /* disable ints from RTC updates. */ | |
288 | gen_clear_rtc_irq_bit(RTC_UIE); | |
289 | return 0; | |
290 | ||
291 | case RTC_UIE_ON: /* enable ints for RTC updates. */ | |
292 | return gen_set_rtc_irq_bit(RTC_UIE); | |
293 | ||
294 | case RTC_RD_TIME: /* Read the time/date from RTC */ | |
295 | /* this doesn't get week-day, who cares */ | |
296 | memset(&wtime, 0, sizeof(wtime)); | |
297 | get_rtc_time(&wtime); | |
298 | ||
299 | return copy_to_user(argp, &wtime, sizeof(wtime)) ? -EFAULT : 0; | |
300 | ||
301 | case RTC_SET_TIME: /* Set the RTC */ | |
302 | { | |
303 | int year; | |
304 | unsigned char leap_yr; | |
305 | ||
306 | if (!capable(CAP_SYS_TIME)) | |
307 | return -EACCES; | |
308 | ||
309 | if (copy_from_user(&wtime, argp, sizeof(wtime))) | |
310 | return -EFAULT; | |
311 | ||
312 | year = wtime.tm_year + 1900; | |
313 | leap_yr = ((!(year % 4) && (year % 100)) || | |
314 | !(year % 400)); | |
315 | ||
316 | if ((wtime.tm_mon < 0 || wtime.tm_mon > 11) || (wtime.tm_mday < 1)) | |
317 | return -EINVAL; | |
318 | ||
319 | if (wtime.tm_mday < 0 || wtime.tm_mday > | |
320 | (days_in_mo[wtime.tm_mon] + ((wtime.tm_mon == 1) && leap_yr))) | |
321 | return -EINVAL; | |
322 | ||
323 | if (wtime.tm_hour < 0 || wtime.tm_hour >= 24 || | |
324 | wtime.tm_min < 0 || wtime.tm_min >= 60 || | |
325 | wtime.tm_sec < 0 || wtime.tm_sec >= 60) | |
326 | return -EINVAL; | |
327 | ||
328 | return set_rtc_time(&wtime); | |
329 | } | |
330 | } | |
331 | ||
332 | return -EINVAL; | |
333 | } | |
334 | ||
55929332 AB |
335 | static long gen_rtc_unlocked_ioctl(struct file *file, unsigned int cmd, |
336 | unsigned long arg) | |
337 | { | |
338 | int ret; | |
339 | ||
613655fa | 340 | mutex_lock(&gen_rtc_mutex); |
55929332 | 341 | ret = gen_rtc_ioctl(file, cmd, arg); |
613655fa | 342 | mutex_unlock(&gen_rtc_mutex); |
55929332 AB |
343 | |
344 | return ret; | |
345 | } | |
346 | ||
1da177e4 LT |
347 | /* |
348 | * We enforce only one user at a time here with the open/close. | |
349 | * Also clear the previous interrupt data on an open, and clean | |
350 | * up things on a close. | |
351 | */ | |
352 | ||
353 | static int gen_rtc_open(struct inode *inode, struct file *file) | |
354 | { | |
613655fa | 355 | mutex_lock(&gen_rtc_mutex); |
742a2fe3 | 356 | if (gen_rtc_status & RTC_IS_OPEN) { |
613655fa | 357 | mutex_unlock(&gen_rtc_mutex); |
1da177e4 | 358 | return -EBUSY; |
742a2fe3 | 359 | } |
1da177e4 LT |
360 | |
361 | gen_rtc_status |= RTC_IS_OPEN; | |
362 | gen_rtc_irq_data = 0; | |
363 | irq_active = 0; | |
613655fa | 364 | mutex_unlock(&gen_rtc_mutex); |
1da177e4 LT |
365 | |
366 | return 0; | |
367 | } | |
368 | ||
369 | static int gen_rtc_release(struct inode *inode, struct file *file) | |
370 | { | |
371 | /* | |
372 | * Turn off all interrupts once the device is no longer | |
373 | * in use and clear the data. | |
374 | */ | |
375 | ||
376 | gen_clear_rtc_irq_bit(RTC_PIE|RTC_AIE|RTC_UIE); | |
377 | ||
378 | gen_rtc_status &= ~RTC_IS_OPEN; | |
379 | return 0; | |
380 | } | |
381 | ||
382 | ||
383 | #ifdef CONFIG_PROC_FS | |
384 | ||
385 | /* | |
c685ce05 | 386 | * Info exported via "/proc/driver/rtc". |
1da177e4 LT |
387 | */ |
388 | ||
389 | static int gen_rtc_proc_output(char *buf) | |
390 | { | |
391 | char *p; | |
392 | struct rtc_time tm; | |
393 | unsigned int flags; | |
394 | struct rtc_pll_info pll; | |
395 | ||
396 | p = buf; | |
397 | ||
398 | flags = get_rtc_time(&tm); | |
399 | ||
400 | p += sprintf(p, | |
401 | "rtc_time\t: %02d:%02d:%02d\n" | |
402 | "rtc_date\t: %04d-%02d-%02d\n" | |
403 | "rtc_epoch\t: %04u\n", | |
404 | tm.tm_hour, tm.tm_min, tm.tm_sec, | |
405 | tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, 1900); | |
406 | ||
407 | tm.tm_hour = tm.tm_min = tm.tm_sec = 0; | |
408 | ||
409 | p += sprintf(p, "alarm\t\t: "); | |
410 | if (tm.tm_hour <= 24) | |
411 | p += sprintf(p, "%02d:", tm.tm_hour); | |
412 | else | |
413 | p += sprintf(p, "**:"); | |
414 | ||
415 | if (tm.tm_min <= 59) | |
416 | p += sprintf(p, "%02d:", tm.tm_min); | |
417 | else | |
418 | p += sprintf(p, "**:"); | |
419 | ||
420 | if (tm.tm_sec <= 59) | |
421 | p += sprintf(p, "%02d\n", tm.tm_sec); | |
422 | else | |
423 | p += sprintf(p, "**\n"); | |
424 | ||
425 | p += sprintf(p, | |
426 | "DST_enable\t: %s\n" | |
427 | "BCD\t\t: %s\n" | |
428 | "24hr\t\t: %s\n" | |
429 | "square_wave\t: %s\n" | |
430 | "alarm_IRQ\t: %s\n" | |
431 | "update_IRQ\t: %s\n" | |
432 | "periodic_IRQ\t: %s\n" | |
433 | "periodic_freq\t: %ld\n" | |
434 | "batt_status\t: %s\n", | |
435 | (flags & RTC_DST_EN) ? "yes" : "no", | |
436 | (flags & RTC_DM_BINARY) ? "no" : "yes", | |
437 | (flags & RTC_24H) ? "yes" : "no", | |
438 | (flags & RTC_SQWE) ? "yes" : "no", | |
439 | (flags & RTC_AIE) ? "yes" : "no", | |
440 | irq_active ? "yes" : "no", | |
441 | (flags & RTC_PIE) ? "yes" : "no", | |
442 | 0L /* freq */, | |
443 | (flags & RTC_BATT_BAD) ? "bad" : "okay"); | |
444 | if (!get_rtc_pll(&pll)) | |
445 | p += sprintf(p, | |
446 | "PLL adjustment\t: %d\n" | |
447 | "PLL max +ve adjustment\t: %d\n" | |
448 | "PLL max -ve adjustment\t: %d\n" | |
449 | "PLL +ve adjustment factor\t: %d\n" | |
450 | "PLL -ve adjustment factor\t: %d\n" | |
451 | "PLL frequency\t: %ld\n", | |
452 | pll.pll_value, | |
453 | pll.pll_max, | |
454 | pll.pll_min, | |
455 | pll.pll_posmult, | |
456 | pll.pll_negmult, | |
457 | pll.pll_clock); | |
458 | return p - buf; | |
459 | } | |
460 | ||
461 | static int gen_rtc_read_proc(char *page, char **start, off_t off, | |
462 | int count, int *eof, void *data) | |
463 | { | |
464 | int len = gen_rtc_proc_output (page); | |
465 | if (len <= off+count) *eof = 1; | |
466 | *start = page + off; | |
467 | len -= off; | |
468 | if (len>count) len = count; | |
469 | if (len<0) len = 0; | |
470 | return len; | |
471 | } | |
472 | ||
473 | static int __init gen_rtc_proc_init(void) | |
474 | { | |
475 | struct proc_dir_entry *r; | |
476 | ||
477 | r = create_proc_read_entry("driver/rtc", 0, NULL, gen_rtc_read_proc, NULL); | |
478 | if (!r) | |
479 | return -ENOMEM; | |
480 | return 0; | |
481 | } | |
482 | #else | |
483 | static inline int gen_rtc_proc_init(void) { return 0; } | |
484 | #endif /* CONFIG_PROC_FS */ | |
485 | ||
486 | ||
487 | /* | |
488 | * The various file operations we support. | |
489 | */ | |
490 | ||
62322d25 | 491 | static const struct file_operations gen_rtc_fops = { |
1da177e4 LT |
492 | .owner = THIS_MODULE, |
493 | #ifdef CONFIG_GEN_RTC_X | |
494 | .read = gen_rtc_read, | |
495 | .poll = gen_rtc_poll, | |
496 | #endif | |
55929332 | 497 | .unlocked_ioctl = gen_rtc_unlocked_ioctl, |
1da177e4 LT |
498 | .open = gen_rtc_open, |
499 | .release = gen_rtc_release, | |
6038f373 | 500 | .llseek = noop_llseek, |
1da177e4 LT |
501 | }; |
502 | ||
503 | static struct miscdevice rtc_gen_dev = | |
504 | { | |
505 | .minor = RTC_MINOR, | |
506 | .name = "rtc", | |
507 | .fops = &gen_rtc_fops, | |
508 | }; | |
509 | ||
510 | static int __init rtc_generic_init(void) | |
511 | { | |
512 | int retval; | |
513 | ||
514 | printk(KERN_INFO "Generic RTC Driver v%s\n", RTC_VERSION); | |
515 | ||
516 | retval = misc_register(&rtc_gen_dev); | |
517 | if (retval < 0) | |
518 | return retval; | |
519 | ||
520 | retval = gen_rtc_proc_init(); | |
521 | if (retval) { | |
522 | misc_deregister(&rtc_gen_dev); | |
523 | return retval; | |
524 | } | |
525 | ||
526 | return 0; | |
527 | } | |
528 | ||
529 | static void __exit rtc_generic_exit(void) | |
530 | { | |
531 | remove_proc_entry ("driver/rtc", NULL); | |
532 | misc_deregister(&rtc_gen_dev); | |
533 | } | |
534 | ||
535 | ||
536 | module_init(rtc_generic_init); | |
537 | module_exit(rtc_generic_exit); | |
538 | ||
539 | MODULE_AUTHOR("Richard Zidlicky"); | |
540 | MODULE_LICENSE("GPL"); | |
541 | MODULE_ALIAS_MISCDEV(RTC_MINOR); |