Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland...
[linux-2.6] / drivers / rtc / rtc-s3c.c
1 /* drivers/rtc/rtc-s3c.c
2  *
3  * Copyright (c) 2004,2006 Simtec Electronics
4  *      Ben Dooks, <ben@simtec.co.uk>
5  *      http://armlinux.simtec.co.uk/
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  * S3C2410/S3C2440/S3C24XX Internal RTC Driver
12 */
13
14 #include <linux/module.h>
15 #include <linux/fs.h>
16 #include <linux/string.h>
17 #include <linux/init.h>
18 #include <linux/platform_device.h>
19 #include <linux/interrupt.h>
20 #include <linux/rtc.h>
21 #include <linux/bcd.h>
22 #include <linux/clk.h>
23
24 #include <asm/hardware.h>
25 #include <asm/uaccess.h>
26 #include <asm/io.h>
27 #include <asm/irq.h>
28 #include <asm/rtc.h>
29
30 #include <asm/mach/time.h>
31
32 #include <asm/arch/regs-rtc.h>
33
34 /* I have yet to find an S3C implementation with more than one
35  * of these rtc blocks in */
36
37 static struct resource *s3c_rtc_mem;
38
39 static void __iomem *s3c_rtc_base;
40 static int s3c_rtc_alarmno = NO_IRQ;
41 static int s3c_rtc_tickno  = NO_IRQ;
42 static int s3c_rtc_freq    = 1;
43
44 static DEFINE_SPINLOCK(s3c_rtc_pie_lock);
45 static unsigned int tick_count;
46
47 /* IRQ Handlers */
48
49 static irqreturn_t s3c_rtc_alarmirq(int irq, void *id, struct pt_regs *r)
50 {
51         struct rtc_device *rdev = id;
52
53         rtc_update_irq(&rdev->class_dev, 1, RTC_AF | RTC_IRQF);
54         return IRQ_HANDLED;
55 }
56
57 static irqreturn_t s3c_rtc_tickirq(int irq, void *id, struct pt_regs *r)
58 {
59         struct rtc_device *rdev = id;
60
61         rtc_update_irq(&rdev->class_dev, tick_count++, RTC_PF | RTC_IRQF);
62         return IRQ_HANDLED;
63 }
64
65 /* Update control registers */
66 static void s3c_rtc_setaie(int to)
67 {
68         unsigned int tmp;
69
70         pr_debug("%s: aie=%d\n", __FUNCTION__, to);
71
72         tmp = readb(S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
73
74         if (to)
75                 tmp |= S3C2410_RTCALM_ALMEN;
76
77         writeb(tmp, S3C2410_RTCALM);
78 }
79
80 static void s3c_rtc_setpie(int to)
81 {
82         unsigned int tmp;
83
84         pr_debug("%s: pie=%d\n", __FUNCTION__, to);
85
86         spin_lock_irq(&s3c_rtc_pie_lock);
87         tmp = readb(S3C2410_TICNT) & ~S3C2410_TICNT_ENABLE;
88
89         if (to)
90                 tmp |= S3C2410_TICNT_ENABLE;
91
92         writeb(tmp, S3C2410_TICNT);
93         spin_unlock_irq(&s3c_rtc_pie_lock);
94 }
95
96 static void s3c_rtc_setfreq(int freq)
97 {
98         unsigned int tmp;
99
100         spin_lock_irq(&s3c_rtc_pie_lock);
101         tmp = readb(S3C2410_TICNT) & S3C2410_TICNT_ENABLE;
102
103         s3c_rtc_freq = freq;
104
105         tmp |= (128 / freq)-1;
106
107         writeb(tmp, S3C2410_TICNT);
108         spin_unlock_irq(&s3c_rtc_pie_lock);
109 }
110
111 /* Time read/write */
112
113 static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
114 {
115         unsigned int have_retried = 0;
116
117  retry_get_time:
118         rtc_tm->tm_min  = readb(S3C2410_RTCMIN);
119         rtc_tm->tm_hour = readb(S3C2410_RTCHOUR);
120         rtc_tm->tm_mday = readb(S3C2410_RTCDATE);
121         rtc_tm->tm_mon  = readb(S3C2410_RTCMON);
122         rtc_tm->tm_year = readb(S3C2410_RTCYEAR);
123         rtc_tm->tm_sec  = readb(S3C2410_RTCSEC);
124
125         /* the only way to work out wether the system was mid-update
126          * when we read it is to check the second counter, and if it
127          * is zero, then we re-try the entire read
128          */
129
130         if (rtc_tm->tm_sec == 0 && !have_retried) {
131                 have_retried = 1;
132                 goto retry_get_time;
133         }
134
135         pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n",
136                  rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
137                  rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
138
139         BCD_TO_BIN(rtc_tm->tm_sec);
140         BCD_TO_BIN(rtc_tm->tm_min);
141         BCD_TO_BIN(rtc_tm->tm_hour);
142         BCD_TO_BIN(rtc_tm->tm_mday);
143         BCD_TO_BIN(rtc_tm->tm_mon);
144         BCD_TO_BIN(rtc_tm->tm_year);
145
146         rtc_tm->tm_year += 100;
147         rtc_tm->tm_mon -= 1;
148
149         return 0;
150 }
151
152 static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
153 {
154         /* the rtc gets round the y2k problem by just not supporting it */
155
156         if (tm->tm_year < 100)
157                 return -EINVAL;
158
159         writeb(BIN2BCD(tm->tm_sec),  S3C2410_RTCSEC);
160         writeb(BIN2BCD(tm->tm_min),  S3C2410_RTCMIN);
161         writeb(BIN2BCD(tm->tm_hour), S3C2410_RTCHOUR);
162         writeb(BIN2BCD(tm->tm_mday), S3C2410_RTCDATE);
163         writeb(BIN2BCD(tm->tm_mon + 1), S3C2410_RTCMON);
164         writeb(BIN2BCD(tm->tm_year - 100), S3C2410_RTCYEAR);
165
166         return 0;
167 }
168
169 static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
170 {
171         struct rtc_time *alm_tm = &alrm->time;
172         unsigned int alm_en;
173
174         alm_tm->tm_sec  = readb(S3C2410_ALMSEC);
175         alm_tm->tm_min  = readb(S3C2410_ALMMIN);
176         alm_tm->tm_hour = readb(S3C2410_ALMHOUR);
177         alm_tm->tm_mon  = readb(S3C2410_ALMMON);
178         alm_tm->tm_mday = readb(S3C2410_ALMDATE);
179         alm_tm->tm_year = readb(S3C2410_ALMYEAR);
180
181         alm_en = readb(S3C2410_RTCALM);
182
183         pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
184                  alm_en,
185                  alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
186                  alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
187
188
189         /* decode the alarm enable field */
190
191         if (alm_en & S3C2410_RTCALM_SECEN)
192                 BCD_TO_BIN(alm_tm->tm_sec);
193         else
194                 alm_tm->tm_sec = 0xff;
195
196         if (alm_en & S3C2410_RTCALM_MINEN)
197                 BCD_TO_BIN(alm_tm->tm_min);
198         else
199                 alm_tm->tm_min = 0xff;
200
201         if (alm_en & S3C2410_RTCALM_HOUREN)
202                 BCD_TO_BIN(alm_tm->tm_hour);
203         else
204                 alm_tm->tm_hour = 0xff;
205
206         if (alm_en & S3C2410_RTCALM_DAYEN)
207                 BCD_TO_BIN(alm_tm->tm_mday);
208         else
209                 alm_tm->tm_mday = 0xff;
210
211         if (alm_en & S3C2410_RTCALM_MONEN) {
212                 BCD_TO_BIN(alm_tm->tm_mon);
213                 alm_tm->tm_mon -= 1;
214         } else {
215                 alm_tm->tm_mon = 0xff;
216         }
217
218         if (alm_en & S3C2410_RTCALM_YEAREN)
219                 BCD_TO_BIN(alm_tm->tm_year);
220         else
221                 alm_tm->tm_year = 0xffff;
222
223         return 0;
224 }
225
226 static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
227 {
228         struct rtc_time *tm = &alrm->time;
229         unsigned int alrm_en;
230
231         pr_debug("s3c_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
232                  alrm->enabled,
233                  tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
234                  tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);
235
236
237         alrm_en = readb(S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
238         writeb(0x00, S3C2410_RTCALM);
239
240         if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
241                 alrm_en |= S3C2410_RTCALM_SECEN;
242                 writeb(BIN2BCD(tm->tm_sec), S3C2410_ALMSEC);
243         }
244
245         if (tm->tm_min < 60 && tm->tm_min >= 0) {
246                 alrm_en |= S3C2410_RTCALM_MINEN;
247                 writeb(BIN2BCD(tm->tm_min), S3C2410_ALMMIN);
248         }
249
250         if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
251                 alrm_en |= S3C2410_RTCALM_HOUREN;
252                 writeb(BIN2BCD(tm->tm_hour), S3C2410_ALMHOUR);
253         }
254
255         pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
256
257         writeb(alrm_en, S3C2410_RTCALM);
258
259         if (0) {
260                 alrm_en = readb(S3C2410_RTCALM);
261                 alrm_en &= ~S3C2410_RTCALM_ALMEN;
262                 writeb(alrm_en, S3C2410_RTCALM);
263                 disable_irq_wake(s3c_rtc_alarmno);
264         }
265
266         if (alrm->enabled)
267                 enable_irq_wake(s3c_rtc_alarmno);
268         else
269                 disable_irq_wake(s3c_rtc_alarmno);
270
271         return 0;
272 }
273
274 static int s3c_rtc_ioctl(struct device *dev,
275                          unsigned int cmd, unsigned long arg)
276 {
277         unsigned int ret = -ENOIOCTLCMD;
278
279         switch (cmd) {
280         case RTC_AIE_OFF:
281         case RTC_AIE_ON:
282                 s3c_rtc_setaie((cmd == RTC_AIE_ON) ? 1 : 0);
283                 ret = 0;
284                 break;
285
286         case RTC_PIE_OFF:
287         case RTC_PIE_ON:
288                 tick_count = 0;
289                 s3c_rtc_setpie((cmd == RTC_PIE_ON) ? 1 : 0);
290                 ret = 0;
291                 break;
292
293         case RTC_IRQP_READ:
294                 ret = put_user(s3c_rtc_freq, (unsigned long __user *)arg);
295                 break;
296
297         case RTC_IRQP_SET:
298                 /* check for power of 2 */
299
300                 if ((arg & (arg-1)) != 0 || arg < 1) {
301                         ret = -EINVAL;
302                         goto exit;
303                 }
304
305                 pr_debug("s3c2410_rtc: setting frequency %ld\n", arg);
306
307                 s3c_rtc_setfreq(arg);
308                 ret = 0;
309                 break;
310
311         case RTC_UIE_ON:
312         case RTC_UIE_OFF:
313                 ret = -EINVAL;
314         }
315
316  exit:
317         return ret;
318 }
319
320 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
321 {
322         unsigned int rtcalm = readb(S3C2410_RTCALM);
323         unsigned int ticnt = readb (S3C2410_TICNT);
324
325         seq_printf(seq, "alarm_IRQ\t: %s\n",
326                    (rtcalm & S3C2410_RTCALM_ALMEN) ? "yes" : "no" );
327
328         seq_printf(seq, "periodic_IRQ\t: %s\n",
329                      (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" );
330
331         seq_printf(seq, "periodic_freq\t: %d\n", s3c_rtc_freq);
332
333         return 0;
334 }
335
336 static int s3c_rtc_open(struct device *dev)
337 {
338         struct platform_device *pdev = to_platform_device(dev);
339         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
340         int ret;
341
342         ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq,
343                           SA_INTERRUPT,  "s3c2410-rtc alarm", rtc_dev);
344
345         if (ret) {
346                 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret);
347                 return ret;
348         }
349
350         ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq,
351                           SA_INTERRUPT,  "s3c2410-rtc tick", rtc_dev);
352
353         if (ret) {
354                 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret);
355                 goto tick_err;
356         }
357
358         return ret;
359
360  tick_err:
361         free_irq(s3c_rtc_alarmno, rtc_dev);
362         return ret;
363 }
364
365 static void s3c_rtc_release(struct device *dev)
366 {
367         struct platform_device *pdev = to_platform_device(dev);
368         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
369
370         /* do not clear AIE here, it may be needed for wake */
371
372         s3c_rtc_setpie(0);
373         free_irq(s3c_rtc_alarmno, rtc_dev);
374         free_irq(s3c_rtc_tickno, rtc_dev);
375 }
376
377 static struct rtc_class_ops s3c_rtcops = {
378         .open           = s3c_rtc_open,
379         .release        = s3c_rtc_release,
380         .ioctl          = s3c_rtc_ioctl,
381         .read_time      = s3c_rtc_gettime,
382         .set_time       = s3c_rtc_settime,
383         .read_alarm     = s3c_rtc_getalarm,
384         .set_alarm      = s3c_rtc_setalarm,
385         .proc           = s3c_rtc_proc,
386 };
387
388 static void s3c_rtc_enable(struct platform_device *pdev, int en)
389 {
390         unsigned int tmp;
391
392         if (s3c_rtc_base == NULL)
393                 return;
394
395         if (!en) {
396                 tmp = readb(S3C2410_RTCCON);
397                 writeb(tmp & ~S3C2410_RTCCON_RTCEN, S3C2410_RTCCON);
398
399                 tmp = readb(S3C2410_TICNT);
400                 writeb(tmp & ~S3C2410_TICNT_ENABLE, S3C2410_TICNT);
401         } else {
402                 /* re-enable the device, and check it is ok */
403
404                 if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){
405                         dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
406
407                         tmp = readb(S3C2410_RTCCON);
408                         writeb(tmp | S3C2410_RTCCON_RTCEN , S3C2410_RTCCON);
409                 }
410
411                 if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){
412                         dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n");
413
414                         tmp = readb(S3C2410_RTCCON);
415                         writeb(tmp& ~S3C2410_RTCCON_CNTSEL , S3C2410_RTCCON);
416                 }
417
418                 if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){
419                         dev_info(&pdev->dev, "removing RTCCON_CLKRST\n");
420
421                         tmp = readb(S3C2410_RTCCON);
422                         writeb(tmp & ~S3C2410_RTCCON_CLKRST, S3C2410_RTCCON);
423                 }
424         }
425 }
426
427 static int s3c_rtc_remove(struct platform_device *dev)
428 {
429         struct rtc_device *rtc = platform_get_drvdata(dev);
430
431         platform_set_drvdata(dev, NULL);
432         rtc_device_unregister(rtc);
433
434         s3c_rtc_setpie(0);
435         s3c_rtc_setaie(0);
436
437         iounmap(s3c_rtc_base);
438         release_resource(s3c_rtc_mem);
439         kfree(s3c_rtc_mem);
440
441         return 0;
442 }
443
444 static int s3c_rtc_probe(struct platform_device *pdev)
445 {
446         struct rtc_device *rtc;
447         struct resource *res;
448         int ret;
449
450         pr_debug("%s: probe=%p\n", __FUNCTION__, pdev);
451
452         /* find the IRQs */
453
454         s3c_rtc_tickno = platform_get_irq(pdev, 1);
455         if (s3c_rtc_tickno < 0) {
456                 dev_err(&pdev->dev, "no irq for rtc tick\n");
457                 return -ENOENT;
458         }
459
460         s3c_rtc_alarmno = platform_get_irq(pdev, 0);
461         if (s3c_rtc_alarmno < 0) {
462                 dev_err(&pdev->dev, "no irq for alarm\n");
463                 return -ENOENT;
464         }
465
466         pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
467                  s3c_rtc_tickno, s3c_rtc_alarmno);
468
469         /* get the memory region */
470
471         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
472         if (res == NULL) {
473                 dev_err(&pdev->dev, "failed to get memory region resource\n");
474                 return -ENOENT;
475         }
476
477         s3c_rtc_mem = request_mem_region(res->start,
478                                              res->end-res->start+1,
479                                              pdev->name);
480
481         if (s3c_rtc_mem == NULL) {
482                 dev_err(&pdev->dev, "failed to reserve memory region\n");
483                 ret = -ENOENT;
484                 goto err_nores;
485         }
486
487         s3c_rtc_base = ioremap(res->start, res->end - res->start + 1);
488         if (s3c_rtc_base == NULL) {
489                 dev_err(&pdev->dev, "failed ioremap()\n");
490                 ret = -EINVAL;
491                 goto err_nomap;
492         }
493
494         /* check to see if everything is setup correctly */
495
496         s3c_rtc_enable(pdev, 1);
497
498         pr_debug("s3c2410_rtc: RTCCON=%02x\n", readb(S3C2410_RTCCON));
499
500         s3c_rtc_setfreq(s3c_rtc_freq);
501
502         /* register RTC and exit */
503
504         rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops,
505                                   THIS_MODULE);
506
507         if (IS_ERR(rtc)) {
508                 dev_err(&pdev->dev, "cannot attach rtc\n");
509                 ret = PTR_ERR(rtc);
510                 goto err_nortc;
511         }
512
513         rtc->max_user_freq = 128;
514
515         platform_set_drvdata(pdev, rtc);
516         return 0;
517
518  err_nortc:
519         s3c_rtc_enable(pdev, 0);
520         iounmap(s3c_rtc_base);
521
522  err_nomap:
523         release_resource(s3c_rtc_mem);
524
525  err_nores:
526         return ret;
527 }
528
529 #ifdef CONFIG_PM
530
531 /* RTC Power management control */
532
533 static struct timespec s3c_rtc_delta;
534
535 static int ticnt_save;
536
537 static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state)
538 {
539         struct rtc_time tm;
540         struct timespec time;
541
542         time.tv_nsec = 0;
543
544         /* save TICNT for anyone using periodic interrupts */
545
546         ticnt_save = readb(S3C2410_TICNT);
547
548         /* calculate time delta for suspend */
549
550         s3c_rtc_gettime(&pdev->dev, &tm);
551         rtc_tm_to_time(&tm, &time.tv_sec);
552         save_time_delta(&s3c_rtc_delta, &time);
553         s3c_rtc_enable(pdev, 0);
554
555         return 0;
556 }
557
558 static int s3c_rtc_resume(struct platform_device *pdev)
559 {
560         struct rtc_time tm;
561         struct timespec time;
562
563         time.tv_nsec = 0;
564
565         s3c_rtc_enable(pdev, 1);
566         s3c_rtc_gettime(&pdev->dev, &tm);
567         rtc_tm_to_time(&tm, &time.tv_sec);
568         restore_time_delta(&s3c_rtc_delta, &time);
569
570         writeb(ticnt_save, S3C2410_TICNT);
571         return 0;
572 }
573 #else
574 #define s3c_rtc_suspend NULL
575 #define s3c_rtc_resume  NULL
576 #endif
577
578 static struct platform_driver s3c2410_rtcdrv = {
579         .probe          = s3c_rtc_probe,
580         .remove         = s3c_rtc_remove,
581         .suspend        = s3c_rtc_suspend,
582         .resume         = s3c_rtc_resume,
583         .driver         = {
584                 .name   = "s3c2410-rtc",
585                 .owner  = THIS_MODULE,
586         },
587 };
588
589 static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n";
590
591 static int __init s3c_rtc_init(void)
592 {
593         printk(banner);
594         return platform_driver_register(&s3c2410_rtcdrv);
595 }
596
597 static void __exit s3c_rtc_exit(void)
598 {
599         platform_driver_unregister(&s3c2410_rtcdrv);
600 }
601
602 module_init(s3c_rtc_init);
603 module_exit(s3c_rtc_exit);
604
605 MODULE_DESCRIPTION("Samsung S3C RTC Driver");
606 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
607 MODULE_LICENSE("GPL");