diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/char/genrtc.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/char/genrtc.c')
-rw-r--r-- | drivers/char/genrtc.c | 535 |
1 files changed, 535 insertions, 0 deletions
diff --git a/drivers/char/genrtc.c b/drivers/char/genrtc.c new file mode 100644 index 000000000000..d3a2bc36129b --- /dev/null +++ b/drivers/char/genrtc.c | |||
@@ -0,0 +1,535 @@ | |||
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 | ||
15 | * interface supporting various ioctl() and also the /proc/dev/rtc | ||
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> | ||
46 | #include <linux/config.h> | ||
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> | ||
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 | */ | ||
106 | static void genrtc_troutine(void *data) | ||
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 | { | ||
177 | DECLARE_WAITQUEUE(wait, current); | ||
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 | |||
187 | add_wait_queue(&gen_rtc_wait, &wait); | ||
188 | retval = -ERESTARTSYS; | ||
189 | |||
190 | while (1) { | ||
191 | set_current_state(TASK_INTERRUPTIBLE); | ||
192 | data = xchg(&gen_rtc_irq_data, 0); | ||
193 | if (data) | ||
194 | break; | ||
195 | if (signal_pending(current)) | ||
196 | goto out; | ||
197 | schedule(); | ||
198 | } | ||
199 | |||
200 | /* first test allows optimizer to nuke this case for 32-bit machines */ | ||
201 | if (sizeof (int) != sizeof (long) && count == sizeof (unsigned int)) { | ||
202 | unsigned int uidata = data; | ||
203 | retval = put_user(uidata, (unsigned long __user *)buf); | ||
204 | } | ||
205 | else { | ||
206 | retval = put_user(data, (unsigned long __user *)buf); | ||
207 | } | ||
208 | if (!retval) | ||
209 | retval = sizeof(unsigned long); | ||
210 | out: | ||
211 | current->state = TASK_RUNNING; | ||
212 | remove_wait_queue(&gen_rtc_wait, &wait); | ||
213 | |||
214 | return retval; | ||
215 | } | ||
216 | |||
217 | static unsigned int gen_rtc_poll(struct file *file, | ||
218 | struct poll_table_struct *wait) | ||
219 | { | ||
220 | poll_wait(file, &gen_rtc_wait, wait); | ||
221 | if (gen_rtc_irq_data != 0) | ||
222 | return POLLIN | POLLRDNORM; | ||
223 | return 0; | ||
224 | } | ||
225 | |||
226 | #endif | ||
227 | |||
228 | /* | ||
229 | * Used to disable/enable interrupts, only RTC_UIE supported | ||
230 | * We also clear out any old irq data after an ioctl() that | ||
231 | * meddles with the interrupt enable/disable bits. | ||
232 | */ | ||
233 | |||
234 | static inline void gen_clear_rtc_irq_bit(unsigned char bit) | ||
235 | { | ||
236 | #ifdef CONFIG_GEN_RTC_X | ||
237 | stop_rtc_timers = 1; | ||
238 | if (ttask_active){ | ||
239 | del_timer_sync(&timer_task); | ||
240 | ttask_active = 0; | ||
241 | } | ||
242 | while (stask_active) | ||
243 | schedule(); | ||
244 | |||
245 | spin_lock(&gen_rtc_lock); | ||
246 | irq_active = 0; | ||
247 | spin_unlock(&gen_rtc_lock); | ||
248 | #endif | ||
249 | } | ||
250 | |||
251 | static inline int gen_set_rtc_irq_bit(unsigned char bit) | ||
252 | { | ||
253 | #ifdef CONFIG_GEN_RTC_X | ||
254 | spin_lock(&gen_rtc_lock); | ||
255 | if ( !irq_active ) { | ||
256 | irq_active = 1; | ||
257 | stop_rtc_timers = 0; | ||
258 | lostint = 0; | ||
259 | INIT_WORK(&genrtc_task, genrtc_troutine, NULL); | ||
260 | oldsecs = get_rtc_ss(); | ||
261 | init_timer(&timer_task); | ||
262 | |||
263 | stask_active = 1; | ||
264 | if (schedule_work(&genrtc_task) == 0){ | ||
265 | stask_active = 0; | ||
266 | } | ||
267 | } | ||
268 | spin_unlock(&gen_rtc_lock); | ||
269 | gen_rtc_irq_data = 0; | ||
270 | return 0; | ||
271 | #else | ||
272 | return -EINVAL; | ||
273 | #endif | ||
274 | } | ||
275 | |||
276 | static int gen_rtc_ioctl(struct inode *inode, struct file *file, | ||
277 | unsigned int cmd, unsigned long arg) | ||
278 | { | ||
279 | struct rtc_time wtime; | ||
280 | struct rtc_pll_info pll; | ||
281 | void __user *argp = (void __user *)arg; | ||
282 | |||
283 | switch (cmd) { | ||
284 | |||
285 | case RTC_PLL_GET: | ||
286 | if (get_rtc_pll(&pll)) | ||
287 | return -EINVAL; | ||
288 | else | ||
289 | return copy_to_user(argp, &pll, sizeof pll) ? -EFAULT : 0; | ||
290 | |||
291 | case RTC_PLL_SET: | ||
292 | if (!capable(CAP_SYS_TIME)) | ||
293 | return -EACCES; | ||
294 | if (copy_from_user(&pll, argp, sizeof(pll))) | ||
295 | return -EFAULT; | ||
296 | return set_rtc_pll(&pll); | ||
297 | |||
298 | case RTC_UIE_OFF: /* disable ints from RTC updates. */ | ||
299 | gen_clear_rtc_irq_bit(RTC_UIE); | ||
300 | return 0; | ||
301 | |||
302 | case RTC_UIE_ON: /* enable ints for RTC updates. */ | ||
303 | return gen_set_rtc_irq_bit(RTC_UIE); | ||
304 | |||
305 | case RTC_RD_TIME: /* Read the time/date from RTC */ | ||
306 | /* this doesn't get week-day, who cares */ | ||
307 | memset(&wtime, 0, sizeof(wtime)); | ||
308 | get_rtc_time(&wtime); | ||
309 | |||
310 | return copy_to_user(argp, &wtime, sizeof(wtime)) ? -EFAULT : 0; | ||
311 | |||
312 | case RTC_SET_TIME: /* Set the RTC */ | ||
313 | { | ||
314 | int year; | ||
315 | unsigned char leap_yr; | ||
316 | |||
317 | if (!capable(CAP_SYS_TIME)) | ||
318 | return -EACCES; | ||
319 | |||
320 | if (copy_from_user(&wtime, argp, sizeof(wtime))) | ||
321 | return -EFAULT; | ||
322 | |||
323 | year = wtime.tm_year + 1900; | ||
324 | leap_yr = ((!(year % 4) && (year % 100)) || | ||
325 | !(year % 400)); | ||
326 | |||
327 | if ((wtime.tm_mon < 0 || wtime.tm_mon > 11) || (wtime.tm_mday < 1)) | ||
328 | return -EINVAL; | ||
329 | |||
330 | if (wtime.tm_mday < 0 || wtime.tm_mday > | ||
331 | (days_in_mo[wtime.tm_mon] + ((wtime.tm_mon == 1) && leap_yr))) | ||
332 | return -EINVAL; | ||
333 | |||
334 | if (wtime.tm_hour < 0 || wtime.tm_hour >= 24 || | ||
335 | wtime.tm_min < 0 || wtime.tm_min >= 60 || | ||
336 | wtime.tm_sec < 0 || wtime.tm_sec >= 60) | ||
337 | return -EINVAL; | ||
338 | |||
339 | return set_rtc_time(&wtime); | ||
340 | } | ||
341 | } | ||
342 | |||
343 | return -EINVAL; | ||
344 | } | ||
345 | |||
346 | /* | ||
347 | * We enforce only one user at a time here with the open/close. | ||
348 | * Also clear the previous interrupt data on an open, and clean | ||
349 | * up things on a close. | ||
350 | */ | ||
351 | |||
352 | static int gen_rtc_open(struct inode *inode, struct file *file) | ||
353 | { | ||
354 | if (gen_rtc_status & RTC_IS_OPEN) | ||
355 | return -EBUSY; | ||
356 | |||
357 | gen_rtc_status |= RTC_IS_OPEN; | ||
358 | gen_rtc_irq_data = 0; | ||
359 | irq_active = 0; | ||
360 | |||
361 | return 0; | ||
362 | } | ||
363 | |||
364 | static int gen_rtc_release(struct inode *inode, struct file *file) | ||
365 | { | ||
366 | /* | ||
367 | * Turn off all interrupts once the device is no longer | ||
368 | * in use and clear the data. | ||
369 | */ | ||
370 | |||
371 | gen_clear_rtc_irq_bit(RTC_PIE|RTC_AIE|RTC_UIE); | ||
372 | |||
373 | gen_rtc_status &= ~RTC_IS_OPEN; | ||
374 | return 0; | ||
375 | } | ||
376 | |||
377 | |||
378 | #ifdef CONFIG_PROC_FS | ||
379 | |||
380 | /* | ||
381 | * Info exported via "/proc/rtc". | ||
382 | */ | ||
383 | |||
384 | static int gen_rtc_proc_output(char *buf) | ||
385 | { | ||
386 | char *p; | ||
387 | struct rtc_time tm; | ||
388 | unsigned int flags; | ||
389 | struct rtc_pll_info pll; | ||
390 | |||
391 | p = buf; | ||
392 | |||
393 | flags = get_rtc_time(&tm); | ||
394 | |||
395 | p += sprintf(p, | ||
396 | "rtc_time\t: %02d:%02d:%02d\n" | ||
397 | "rtc_date\t: %04d-%02d-%02d\n" | ||
398 | "rtc_epoch\t: %04u\n", | ||
399 | tm.tm_hour, tm.tm_min, tm.tm_sec, | ||
400 | tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, 1900); | ||
401 | |||
402 | tm.tm_hour = tm.tm_min = tm.tm_sec = 0; | ||
403 | |||
404 | p += sprintf(p, "alarm\t\t: "); | ||
405 | if (tm.tm_hour <= 24) | ||
406 | p += sprintf(p, "%02d:", tm.tm_hour); | ||
407 | else | ||
408 | p += sprintf(p, "**:"); | ||
409 | |||
410 | if (tm.tm_min <= 59) | ||
411 | p += sprintf(p, "%02d:", tm.tm_min); | ||
412 | else | ||
413 | p += sprintf(p, "**:"); | ||
414 | |||
415 | if (tm.tm_sec <= 59) | ||
416 | p += sprintf(p, "%02d\n", tm.tm_sec); | ||
417 | else | ||
418 | p += sprintf(p, "**\n"); | ||
419 | |||
420 | p += sprintf(p, | ||
421 | "DST_enable\t: %s\n" | ||
422 | "BCD\t\t: %s\n" | ||
423 | "24hr\t\t: %s\n" | ||
424 | "square_wave\t: %s\n" | ||
425 | "alarm_IRQ\t: %s\n" | ||
426 | "update_IRQ\t: %s\n" | ||
427 | "periodic_IRQ\t: %s\n" | ||
428 | "periodic_freq\t: %ld\n" | ||
429 | "batt_status\t: %s\n", | ||
430 | (flags & RTC_DST_EN) ? "yes" : "no", | ||
431 | (flags & RTC_DM_BINARY) ? "no" : "yes", | ||
432 | (flags & RTC_24H) ? "yes" : "no", | ||
433 | (flags & RTC_SQWE) ? "yes" : "no", | ||
434 | (flags & RTC_AIE) ? "yes" : "no", | ||
435 | irq_active ? "yes" : "no", | ||
436 | (flags & RTC_PIE) ? "yes" : "no", | ||
437 | 0L /* freq */, | ||
438 | (flags & RTC_BATT_BAD) ? "bad" : "okay"); | ||
439 | if (!get_rtc_pll(&pll)) | ||
440 | p += sprintf(p, | ||
441 | "PLL adjustment\t: %d\n" | ||
442 | "PLL max +ve adjustment\t: %d\n" | ||
443 | "PLL max -ve adjustment\t: %d\n" | ||
444 | "PLL +ve adjustment factor\t: %d\n" | ||
445 | "PLL -ve adjustment factor\t: %d\n" | ||
446 | "PLL frequency\t: %ld\n", | ||
447 | pll.pll_value, | ||
448 | pll.pll_max, | ||
449 | pll.pll_min, | ||
450 | pll.pll_posmult, | ||
451 | pll.pll_negmult, | ||
452 | pll.pll_clock); | ||
453 | return p - buf; | ||
454 | } | ||
455 | |||
456 | static int gen_rtc_read_proc(char *page, char **start, off_t off, | ||
457 | int count, int *eof, void *data) | ||
458 | { | ||
459 | int len = gen_rtc_proc_output (page); | ||
460 | if (len <= off+count) *eof = 1; | ||
461 | *start = page + off; | ||
462 | len -= off; | ||
463 | if (len>count) len = count; | ||
464 | if (len<0) len = 0; | ||
465 | return len; | ||
466 | } | ||
467 | |||
468 | static int __init gen_rtc_proc_init(void) | ||
469 | { | ||
470 | struct proc_dir_entry *r; | ||
471 | |||
472 | r = create_proc_read_entry("driver/rtc", 0, NULL, gen_rtc_read_proc, NULL); | ||
473 | if (!r) | ||
474 | return -ENOMEM; | ||
475 | return 0; | ||
476 | } | ||
477 | #else | ||
478 | static inline int gen_rtc_proc_init(void) { return 0; } | ||
479 | #endif /* CONFIG_PROC_FS */ | ||
480 | |||
481 | |||
482 | /* | ||
483 | * The various file operations we support. | ||
484 | */ | ||
485 | |||
486 | static struct file_operations gen_rtc_fops = { | ||
487 | .owner = THIS_MODULE, | ||
488 | #ifdef CONFIG_GEN_RTC_X | ||
489 | .read = gen_rtc_read, | ||
490 | .poll = gen_rtc_poll, | ||
491 | #endif | ||
492 | .ioctl = gen_rtc_ioctl, | ||
493 | .open = gen_rtc_open, | ||
494 | .release = gen_rtc_release, | ||
495 | }; | ||
496 | |||
497 | static struct miscdevice rtc_gen_dev = | ||
498 | { | ||
499 | .minor = RTC_MINOR, | ||
500 | .name = "rtc", | ||
501 | .fops = &gen_rtc_fops, | ||
502 | }; | ||
503 | |||
504 | static int __init rtc_generic_init(void) | ||
505 | { | ||
506 | int retval; | ||
507 | |||
508 | printk(KERN_INFO "Generic RTC Driver v%s\n", RTC_VERSION); | ||
509 | |||
510 | retval = misc_register(&rtc_gen_dev); | ||
511 | if (retval < 0) | ||
512 | return retval; | ||
513 | |||
514 | retval = gen_rtc_proc_init(); | ||
515 | if (retval) { | ||
516 | misc_deregister(&rtc_gen_dev); | ||
517 | return retval; | ||
518 | } | ||
519 | |||
520 | return 0; | ||
521 | } | ||
522 | |||
523 | static void __exit rtc_generic_exit(void) | ||
524 | { | ||
525 | remove_proc_entry ("driver/rtc", NULL); | ||
526 | misc_deregister(&rtc_gen_dev); | ||
527 | } | ||
528 | |||
529 | |||
530 | module_init(rtc_generic_init); | ||
531 | module_exit(rtc_generic_exit); | ||
532 | |||
533 | MODULE_AUTHOR("Richard Zidlicky"); | ||
534 | MODULE_LICENSE("GPL"); | ||
535 | MODULE_ALIAS_MISCDEV(RTC_MINOR); | ||