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> | |
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 | ||
67 | static 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 | ||
75 | static unsigned char gen_rtc_status; /* bitmapped status byte. */ | |
76 | static unsigned long gen_rtc_irq_data; /* our output to the world */ | |
77 | ||
78 | /* months start at 0 now */ | |
79 | static unsigned char days_in_mo[] = | |
80 | {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; | |
81 | ||
82 | static int irq_active; | |
83 | ||
84 | #ifdef CONFIG_GEN_RTC_X | |
85 | static struct work_struct genrtc_task; | |
86 | static struct timer_list timer_task; | |
87 | ||
88 | static unsigned int oldsecs; | |
89 | static int lostint; | |
90 | static unsigned long tt_exp; | |
91 | ||
92 | static void gen_rtc_timer(unsigned long data); | |
93 | ||
94 | static volatile int stask_active; /* schedule_work */ | |
95 | static volatile int ttask_active; /* timer_task */ | |
96 | static int stop_rtc_timers; /* don't requeue tasks */ | |
97 | static DEFINE_SPINLOCK(gen_rtc_lock); | |
98 | ||
99 | static 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 | */ | |
c4028958 | 105 | static void genrtc_troutine(struct work_struct *work) |
1da177e4 LT |
106 | { |
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 | ||
129 | static 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 | */ | |
150 | static 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 | */ | |
173 | static ssize_t gen_rtc_read(struct file *file, char __user *buf, | |
174 | size_t count, loff_t *ppos) | |
175 | { | |
1da177e4 LT |
176 | 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 | ||
e0955e14 JS |
185 | retval = wait_event_interruptible(gen_rtc_wait, |
186 | (data = xchg(&gen_rtc_irq_data, 0))); | |
187 | if (retval) | |
188 | goto out; | |
1da177e4 LT |
189 | |
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; | |
f3537ea7 AN |
193 | retval = put_user(uidata, (unsigned int __user *)buf) ?: |
194 | sizeof(unsigned int); | |
1da177e4 LT |
195 | } |
196 | else { | |
f3537ea7 AN |
197 | retval = put_user(data, (unsigned long __user *)buf) ?: |
198 | sizeof(unsigned long); | |
1da177e4 | 199 | } |
e0955e14 | 200 | out: |
1da177e4 LT |
201 | return retval; |
202 | } | |
203 | ||
204 | static 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 | ||
221 | static 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 | ||
238 | static 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; | |
c4028958 | 246 | INIT_WORK(&genrtc_task, genrtc_troutine); |
1da177e4 LT |
247 | 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 | ||
263 | static 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 | ||
339 | static 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 | ||
351 | static 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 | /* | |
c685ce05 | 368 | * Info exported via "/proc/driver/rtc". |
1da177e4 LT |
369 | */ |
370 | ||
371 | static 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 | ||
443 | static 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 | ||
455 | static 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 | |
465 | static 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 | ||
62322d25 | 473 | static const struct file_operations gen_rtc_fops = { |
1da177e4 LT |
474 | .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 | ||
484 | static struct miscdevice rtc_gen_dev = | |
485 | { | |
486 | .minor = RTC_MINOR, | |
487 | .name = "rtc", | |
488 | .fops = &gen_rtc_fops, | |
489 | }; | |
490 | ||
491 | static 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 | ||
510 | static void __exit rtc_generic_exit(void) | |
511 | { | |
512 | remove_proc_entry ("driver/rtc", NULL); | |
513 | misc_deregister(&rtc_gen_dev); | |
514 | } | |
515 | ||
516 | ||
517 | module_init(rtc_generic_init); | |
518 | module_exit(rtc_generic_exit); | |
519 | ||
520 | MODULE_AUTHOR("Richard Zidlicky"); | |
521 | MODULE_LICENSE("GPL"); | |
522 | MODULE_ALIAS_MISCDEV(RTC_MINOR); |