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