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Linux-2.6.12-rc2
[linux-2.6/kvm.git] / drivers / char / s3c2410-rtc.c
blobec666395a26cb33009fb75aa1cc68c10f5173a58
1 /* drivers/char/s3c2410_rtc.c
2 *
3 * Copyright (c) 2004 Simtec Electronics <linux@simtec.co.uk>
4 * http://www.simtec.co.uk/products/SWLINUX/
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * S3C2410 Internal RTC Driver
11 *
12 * Changelog:
13 * 08-Nov-2004 BJD Initial creation
14 * 12-Nov-2004 BJD Added periodic IRQ and PM code
15 * 22-Nov-2004 BJD Sign-test on alarm code to check for <0
16 * 10-Mar-2005 LCVR Changed S3C2410_VA_RTC to S3C24XX_VA_RTC
17 */
18
19 #include <linux/module.h>
20 #include <linux/fs.h>
21 #include <linux/string.h>
22 #include <linux/init.h>
23 #include <linux/device.h>
24 #include <linux/interrupt.h>
25 #include <linux/rtc.h>
26 #include <linux/bcd.h>
27
28 #include <asm/hardware.h>
29 #include <asm/uaccess.h>
30 #include <asm/io.h>
31 #include <asm/irq.h>
32 #include <asm/rtc.h>
33
34 #include <asm/mach/time.h>
35
36 #include <asm/hardware/clock.h>
37 #include <asm/arch/regs-rtc.h>
38
39 /* need this for the RTC_AF definitions */
40 #include <linux/mc146818rtc.h>
41
42 #undef S3C24XX_VA_RTC
43 #define S3C24XX_VA_RTC s3c2410_rtc_base
44
45 static struct resource *s3c2410_rtc_mem;
46
47 static void __iomem *s3c2410_rtc_base;
48 static int s3c2410_rtc_alarmno = NO_IRQ;
49 static int s3c2410_rtc_tickno = NO_IRQ;
50 static int s3c2410_rtc_freq = 1;
51
52 static DEFINE_SPINLOCK(s3c2410_rtc_pie_lock);
53
54 /* IRQ Handlers */
55
56 static irqreturn_t s3c2410_rtc_alarmirq(int irq, void *id, struct pt_regs *r)
57 {
58 rtc_update(1, RTC_AF | RTC_IRQF);
59 return IRQ_HANDLED;
60 }
61
62 static irqreturn_t s3c2410_rtc_tickirq(int irq, void *id, struct pt_regs *r)
63 {
64 rtc_update(1, RTC_PF | RTC_IRQF);
65 return IRQ_HANDLED;
66 }
67
68 /* Update control registers */
69 static void s3c2410_rtc_setaie(int to)
70 {
71 unsigned int tmp;
72
73 pr_debug("%s: aie=%d\n", __FUNCTION__, to);
74
75 tmp = readb(S3C2410_RTCALM);
76
77 if (to)
78 tmp |= S3C2410_RTCALM_ALMEN;
79 else
80 tmp &= ~S3C2410_RTCALM_ALMEN;
81
82
83 writeb(tmp, S3C2410_RTCALM);
84 }
85
86 static void s3c2410_rtc_setpie(int to)
87 {
88 unsigned int tmp;
89
90 pr_debug("%s: pie=%d\n", __FUNCTION__, to);
91
92 spin_lock_irq(&s3c2410_rtc_pie_lock);
93 tmp = readb(S3C2410_TICNT) & ~S3C2410_TICNT_ENABLE;
94
95 if (to)
96 tmp |= S3C2410_TICNT_ENABLE;
97
98 writeb(tmp, S3C2410_TICNT);
99 spin_unlock_irq(&s3c2410_rtc_pie_lock);
100 }
101
102 static void s3c2410_rtc_setfreq(int freq)
103 {
104 unsigned int tmp;
105
106 spin_lock_irq(&s3c2410_rtc_pie_lock);
107 tmp = readb(S3C2410_TICNT) & S3C2410_TICNT_ENABLE;
108
109 s3c2410_rtc_freq = freq;
110
111 tmp |= (128 / freq)-1;
112
113 writeb(tmp, S3C2410_TICNT);
114 spin_unlock_irq(&s3c2410_rtc_pie_lock);
115 }
116
117 /* Time read/write */
118
119 static void s3c2410_rtc_gettime(struct rtc_time *rtc_tm)
120 {
121 unsigned int have_retried = 0;
122
123 retry_get_time:
124 rtc_tm->tm_min = readb(S3C2410_RTCMIN);
125 rtc_tm->tm_hour = readb(S3C2410_RTCHOUR);
126 rtc_tm->tm_mday = readb(S3C2410_RTCDATE);
127 rtc_tm->tm_mon = readb(S3C2410_RTCMON);
128 rtc_tm->tm_year = readb(S3C2410_RTCYEAR);
129 rtc_tm->tm_sec = readb(S3C2410_RTCSEC);
130
131 /* the only way to work out wether the system was mid-update
132 * when we read it is to check the second counter, and if it
133 * is zero, then we re-try the entire read
134 */
135
136 if (rtc_tm->tm_sec == 0 && !have_retried) {
137 have_retried = 1;
138 goto retry_get_time;
139 }
140
141 pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n",
142 rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
143 rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
144
145 BCD_TO_BIN(rtc_tm->tm_sec);
146 BCD_TO_BIN(rtc_tm->tm_min);
147 BCD_TO_BIN(rtc_tm->tm_hour);
148 BCD_TO_BIN(rtc_tm->tm_mday);
149 BCD_TO_BIN(rtc_tm->tm_mon);
150 BCD_TO_BIN(rtc_tm->tm_year);
151
152 rtc_tm->tm_year += 100;
153 rtc_tm->tm_mon -= 1;
154 }
155
156
157 static int s3c2410_rtc_settime(struct rtc_time *tm)
158 {
159 /* the rtc gets round the y2k problem by just not supporting it */
160
161 if (tm->tm_year < 100)
162 return -EINVAL;
163
164 writeb(BIN2BCD(tm->tm_sec), S3C2410_RTCSEC);
165 writeb(BIN2BCD(tm->tm_min), S3C2410_RTCMIN);
166 writeb(BIN2BCD(tm->tm_hour), S3C2410_RTCHOUR);
167 writeb(BIN2BCD(tm->tm_mday), S3C2410_RTCDATE);
168 writeb(BIN2BCD(tm->tm_mon + 1), S3C2410_RTCMON);
169 writeb(BIN2BCD(tm->tm_year - 100), S3C2410_RTCYEAR);
170
171 return 0;
172 }
173
174 static void s3c2410_rtc_getalarm(struct rtc_wkalrm *alrm)
175 {
176 struct rtc_time *alm_tm = &alrm->time;
177 unsigned int alm_en;
178
179 alm_tm->tm_sec = readb(S3C2410_ALMSEC);
180 alm_tm->tm_min = readb(S3C2410_ALMMIN);
181 alm_tm->tm_hour = readb(S3C2410_ALMHOUR);
182 alm_tm->tm_mon = readb(S3C2410_ALMMON);
183 alm_tm->tm_mday = readb(S3C2410_ALMDATE);
184 alm_tm->tm_year = readb(S3C2410_ALMYEAR);
185
186 alm_en = readb(S3C2410_RTCALM);
187
188 pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
189 alm_en,
190 alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
191 alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
192
193
194 /* decode the alarm enable field */
195
196 if (alm_en & S3C2410_RTCALM_SECEN) {
197 BCD_TO_BIN(alm_tm->tm_sec);
198 } else {
199 alm_tm->tm_sec = 0xff;
200 }
201
202 if (alm_en & S3C2410_RTCALM_MINEN) {
203 BCD_TO_BIN(alm_tm->tm_min);
204 } else {
205 alm_tm->tm_min = 0xff;
206 }
207
208 if (alm_en & S3C2410_RTCALM_HOUREN) {
209 BCD_TO_BIN(alm_tm->tm_hour);
210 } else {
211 alm_tm->tm_hour = 0xff;
212 }
213
214 if (alm_en & S3C2410_RTCALM_DAYEN) {
215 BCD_TO_BIN(alm_tm->tm_mday);
216 } else {
217 alm_tm->tm_mday = 0xff;
218 }
219
220 if (alm_en & S3C2410_RTCALM_MONEN) {
221 BCD_TO_BIN(alm_tm->tm_mon);
222 alm_tm->tm_mon -= 1;
223 } else {
224 alm_tm->tm_mon = 0xff;
225 }
226
227 if (alm_en & S3C2410_RTCALM_YEAREN) {
228 BCD_TO_BIN(alm_tm->tm_year);
229 } else {
230 alm_tm->tm_year = 0xffff;
231 }
232
233 /* todo - set alrm->enabled ? */
234 }
235
236 static int s3c2410_rtc_setalarm(struct rtc_wkalrm *alrm)
237 {
238 struct rtc_time *tm = &alrm->time;
239 unsigned int alrm_en;
240
241 pr_debug("s3c2410_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
242 alrm->enabled,
243 tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
244 tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);
245
246 if (alrm->enabled || 1) {
247 alrm_en = readb(S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
248 writeb(0x00, S3C2410_RTCALM);
249
250 if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
251 alrm_en |= S3C2410_RTCALM_SECEN;
252 writeb(BIN2BCD(tm->tm_sec), S3C2410_ALMSEC);
253 }
254
255 if (tm->tm_min < 60 && tm->tm_min >= 0) {
256 alrm_en |= S3C2410_RTCALM_MINEN;
257 writeb(BIN2BCD(tm->tm_min), S3C2410_ALMMIN);
258 }
259
260 if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
261 alrm_en |= S3C2410_RTCALM_HOUREN;
262 writeb(BIN2BCD(tm->tm_hour), S3C2410_ALMHOUR);
263 }
264
265 pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
266
267 writeb(alrm_en, S3C2410_RTCALM);
268 enable_irq_wake(s3c2410_rtc_alarmno);
269 } else {
270 alrm_en = readb(S3C2410_RTCALM);
271 alrm_en &= ~S3C2410_RTCALM_ALMEN;
272 writeb(alrm_en, S3C2410_RTCALM);
273 disable_irq_wake(s3c2410_rtc_alarmno);
274 }
275
276 return 0;
277 }
278
279 static int s3c2410_rtc_ioctl(unsigned int cmd, unsigned long arg)
280 {
281 switch (cmd) {
282 case RTC_AIE_OFF:
283 case RTC_AIE_ON:
284 s3c2410_rtc_setaie((cmd == RTC_AIE_ON) ? 1 : 0);
285 return 0;
286
287 case RTC_PIE_OFF:
288 case RTC_PIE_ON:
289 s3c2410_rtc_setpie((cmd == RTC_PIE_ON) ? 1 : 0);
290 return 0;
291
292 case RTC_IRQP_READ:
293 return put_user(s3c2410_rtc_freq, (unsigned long __user *)arg);
294
295 case RTC_IRQP_SET:
296 if (arg < 1 || arg > 64)
297 return -EINVAL;
298
299 if (!capable(CAP_SYS_RESOURCE))
300 return -EACCES;
301
302 /* check for power of 2 */
303
304 if ((arg & (arg-1)) != 0)
305 return -EINVAL;
306
307 pr_debug("s3c2410_rtc: setting frequency %ld\n", arg);
308
309 s3c2410_rtc_setfreq(arg);
310 return 0;
311
312 case RTC_UIE_ON:
313 case RTC_UIE_OFF:
314 return -EINVAL;
315 }
316
317 return -EINVAL;
318 }
319
320 static int s3c2410_rtc_proc(char *buf)
321 {
322 unsigned int rtcalm = readb(S3C2410_RTCALM);
323 unsigned int ticnt = readb (S3C2410_TICNT);
324 char *p = buf;
325
326 p += sprintf(p, "alarm_IRQ\t: %s\n",
327 (rtcalm & S3C2410_RTCALM_ALMEN) ? "yes" : "no" );
328 p += sprintf(p, "periodic_IRQ\t: %s\n",
329 (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" );
330 p += sprintf(p, "periodic_freq\t: %d\n", s3c2410_rtc_freq);
331
332 return p - buf;
333 }
334
335 static int s3c2410_rtc_open(void)
336 {
337 int ret;
338
339 ret = request_irq(s3c2410_rtc_alarmno, s3c2410_rtc_alarmirq,
340 SA_INTERRUPT, "s3c2410-rtc alarm", NULL);
341
342 if (ret)
343 printk(KERN_ERR "IRQ%d already in use\n", s3c2410_rtc_alarmno);
344
345 ret = request_irq(s3c2410_rtc_tickno, s3c2410_rtc_tickirq,
346 SA_INTERRUPT, "s3c2410-rtc tick", NULL);
347
348 if (ret) {
349 printk(KERN_ERR "IRQ%d already in use\n", s3c2410_rtc_tickno);
350 goto tick_err;
351 }
352
353 return ret;
354
355 tick_err:
356 free_irq(s3c2410_rtc_alarmno, NULL);
357 return ret;
358 }
359
360 static void s3c2410_rtc_release(void)
361 {
362 /* do not clear AIE here, it may be needed for wake */
363
364 s3c2410_rtc_setpie(0);
365 free_irq(s3c2410_rtc_alarmno, NULL);
366 free_irq(s3c2410_rtc_tickno, NULL);
367 }
368
369 static struct rtc_ops s3c2410_rtcops = {
370 .owner = THIS_MODULE,
371 .open = s3c2410_rtc_open,
372 .release = s3c2410_rtc_release,
373 .ioctl = s3c2410_rtc_ioctl,
374 .read_time = s3c2410_rtc_gettime,
375 .set_time = s3c2410_rtc_settime,
376 .read_alarm = s3c2410_rtc_getalarm,
377 .set_alarm = s3c2410_rtc_setalarm,
378 .proc = s3c2410_rtc_proc,
379 };
380
381 static void s3c2410_rtc_enable(struct device *dev, int en)
382 {
383 unsigned int tmp;
384
385 if (s3c2410_rtc_base == NULL)
386 return;
387
388 if (!en) {
389 tmp = readb(S3C2410_RTCCON);
390 writeb(tmp & ~S3C2410_RTCCON_RTCEN, S3C2410_RTCCON);
391
392 tmp = readb(S3C2410_TICNT);
393 writeb(tmp & ~S3C2410_TICNT_ENABLE, S3C2410_TICNT);
394 } else {
395 /* re-enable the device, and check it is ok */
396
397 if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){
398 dev_info(dev, "rtc disabled, re-enabling\n");
399
400 tmp = readb(S3C2410_RTCCON);
401 writeb(tmp | S3C2410_RTCCON_RTCEN , S3C2410_RTCCON);
402 }
403
404 if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){
405 dev_info(dev, "removing S3C2410_RTCCON_CNTSEL\n");
406
407 tmp = readb(S3C2410_RTCCON);
408 writeb(tmp& ~S3C2410_RTCCON_CNTSEL , S3C2410_RTCCON);
409 }
410
411 if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){
412 dev_info(dev, "removing S3C2410_RTCCON_CLKRST\n");
413
414 tmp = readb(S3C2410_RTCCON);
415 writeb(tmp & ~S3C2410_RTCCON_CLKRST, S3C2410_RTCCON);
416 }
417 }
418 }
419
420 static int s3c2410_rtc_remove(struct device *dev)
421 {
422 unregister_rtc(&s3c2410_rtcops);
423
424 s3c2410_rtc_setpie(0);
425 s3c2410_rtc_setaie(0);
426
427 if (s3c2410_rtc_mem != NULL) {
428 pr_debug("s3c2410_rtc: releasing s3c2410_rtc_mem\n");
429 iounmap(s3c2410_rtc_base);
430 release_resource(s3c2410_rtc_mem);
431 kfree(s3c2410_rtc_mem);
432 }
433
434 return 0;
435 }
436
437 static int s3c2410_rtc_probe(struct device *dev)
438 {
439 struct platform_device *pdev = to_platform_device(dev);
440 struct resource *res;
441 int ret;
442
443 pr_debug("%s: probe=%p, device=%p\n", __FUNCTION__, pdev, dev);
444
445 /* find the IRQs */
446
447 s3c2410_rtc_tickno = platform_get_irq(pdev, 1);
448 if (s3c2410_rtc_tickno <= 0) {
449 dev_err(dev, "no irq for rtc tick\n");
450 return -ENOENT;
451 }
452
453 s3c2410_rtc_alarmno = platform_get_irq(pdev, 0);
454 if (s3c2410_rtc_alarmno <= 0) {
455 dev_err(dev, "no irq for alarm\n");
456 return -ENOENT;
457 }
458
459 pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
460 s3c2410_rtc_tickno, s3c2410_rtc_alarmno);
461
462 /* get the memory region */
463
464 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
465 if (res == NULL) {
466 dev_err(dev, "failed to get memory region resource\n");
467 return -ENOENT;
468 }
469
470 s3c2410_rtc_mem = request_mem_region(res->start, res->end-res->start+1,
471 pdev->name);
472
473 if (s3c2410_rtc_mem == NULL) {
474 dev_err(dev, "failed to reserve memory region\n");
475 ret = -ENOENT;
476 goto exit_err;
477 }
478
479 s3c2410_rtc_base = ioremap(res->start, res->end - res->start + 1);
480 if (s3c2410_rtc_base == NULL) {
481 dev_err(dev, "failed ioremap()\n");
482 ret = -EINVAL;
483 goto exit_err;
484 }
485
486 s3c2410_rtc_mem = res;
487 pr_debug("s3c2410_rtc_base=%p\n", s3c2410_rtc_base);
488
489 pr_debug("s3c2410_rtc: RTCCON=%02x\n", readb(S3C2410_RTCCON));
490
491 /* check to see if everything is setup correctly */
492
493 s3c2410_rtc_enable(dev, 1);
494
495 pr_debug("s3c2410_rtc: RTCCON=%02x\n", readb(S3C2410_RTCCON));
496
497 s3c2410_rtc_setfreq(s3c2410_rtc_freq);
498
499 /* register RTC and exit */
500
501 register_rtc(&s3c2410_rtcops);
502 return 0;
503
504 exit_err:
505 dev_err(dev, "error %d during initialisation\n", ret);
506
507 return ret;
508 }
509
510 #ifdef CONFIG_PM
511
512 /* S3C2410 RTC Power management control */
513
514 static struct timespec s3c2410_rtc_delta;
515
516 static int ticnt_save;
517
518 static int s3c2410_rtc_suspend(struct device *dev, u32 state, u32 level)
519 {
520 struct rtc_time tm;
521 struct timespec time;
522
523 time.tv_nsec = 0;
524
525 if (level == SUSPEND_POWER_DOWN) {
526 /* save TICNT for anyone using periodic interrupts */
527
528 ticnt_save = readb(S3C2410_TICNT);
529
530 /* calculate time delta for suspend */
531
532 s3c2410_rtc_gettime(&tm);
533 rtc_tm_to_time(&tm, &time.tv_sec);
534 save_time_delta(&s3c2410_rtc_delta, &time);
535 s3c2410_rtc_enable(dev, 0);
536 }
537
538 return 0;
539 }
540
541 static int s3c2410_rtc_resume(struct device *dev, u32 level)
542 {
543 struct rtc_time tm;
544 struct timespec time;
545
546 time.tv_nsec = 0;
547
548 s3c2410_rtc_enable(dev, 1);
549 s3c2410_rtc_gettime(&tm);
550 rtc_tm_to_time(&tm, &time.tv_sec);
551 restore_time_delta(&s3c2410_rtc_delta, &time);
552
553 writeb(ticnt_save, S3C2410_TICNT);
554 return 0;
555 }
556 #else
557 #define s3c2410_rtc_suspend NULL
558 #define s3c2410_rtc_resume NULL
559 #endif
560
561 static struct device_driver s3c2410_rtcdrv = {
562 .name = "s3c2410-rtc",
563 .bus = &platform_bus_type,
564 .probe = s3c2410_rtc_probe,
565 .remove = s3c2410_rtc_remove,
566 .suspend = s3c2410_rtc_suspend,
567 .resume = s3c2410_rtc_resume,
568 };
569
570 static char __initdata banner[] = "S3C2410 RTC, (c) 2004 Simtec Electronics\n";
571
572 static int __init s3c2410_rtc_init(void)
573 {
574 printk(banner);
575 return driver_register(&s3c2410_rtcdrv);
576 }
577
578 static void __exit s3c2410_rtc_exit(void)
579 {
580 driver_unregister(&s3c2410_rtcdrv);
581 }
582
583 module_init(s3c2410_rtc_init);
584 module_exit(s3c2410_rtc_exit);
585
586 MODULE_DESCRIPTION("S3C24XX RTC Driver");
587 MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
588 MODULE_LICENSE("GPL");
kernel-based virtual machine