e301dea57bb37fff0918791a2f6e74117c079b88
[linux-2.6.git] / 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)
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)
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(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
73
74         if (to)
75                 tmp |= S3C2410_RTCALM_ALMEN;
76
77         writeb(tmp, s3c_rtc_base + 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(s3c_rtc_base + S3C2410_TICNT) & ~S3C2410_TICNT_ENABLE;
88
89         if (to)
90                 tmp |= S3C2410_TICNT_ENABLE;
91
92         writeb(tmp, s3c_rtc_base + 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(s3c_rtc_base + S3C2410_TICNT) & S3C2410_TICNT_ENABLE;
102
103         s3c_rtc_freq = freq;
104
105         tmp |= (128 / freq)-1;
106
107         writeb(tmp, s3c_rtc_base + 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         void __iomem *base = s3c_rtc_base;
117
118  retry_get_time:
119         rtc_tm->tm_min  = readb(base + S3C2410_RTCMIN);
120         rtc_tm->tm_hour = readb(base + S3C2410_RTCHOUR);
121         rtc_tm->tm_mday = readb(base + S3C2410_RTCDATE);
122         rtc_tm->tm_mon  = readb(base + S3C2410_RTCMON);
123         rtc_tm->tm_year = readb(base + S3C2410_RTCYEAR);
124         rtc_tm->tm_sec  = readb(base + S3C2410_RTCSEC);
125
126         /* the only way to work out wether the system was mid-update
127          * when we read it is to check the second counter, and if it
128          * is zero, then we re-try the entire read
129          */
130
131         if (rtc_tm->tm_sec == 0 && !have_retried) {
132                 have_retried = 1;
133                 goto retry_get_time;
134         }
135
136         pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n",
137                  rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
138                  rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
139
140         BCD_TO_BIN(rtc_tm->tm_sec);
141         BCD_TO_BIN(rtc_tm->tm_min);
142         BCD_TO_BIN(rtc_tm->tm_hour);
143         BCD_TO_BIN(rtc_tm->tm_mday);
144         BCD_TO_BIN(rtc_tm->tm_mon);
145         BCD_TO_BIN(rtc_tm->tm_year);
146
147         rtc_tm->tm_year += 100;
148         rtc_tm->tm_mon -= 1;
149
150         return 0;
151 }
152
153 static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
154 {
155         void __iomem *base = s3c_rtc_base;
156         int year = tm->tm_year - 100;
157
158         pr_debug("set time %02d.%02d.%02d %02d/%02d/%02d\n",
159                  tm->tm_year, tm->tm_mon, tm->tm_mday,
160                  tm->tm_hour, tm->tm_min, tm->tm_sec);
161
162         /* we get around y2k by simply not supporting it */
163
164         if (year < 0 || year >= 100) {
165                 dev_err(dev, "rtc only supports 100 years\n");
166                 return -EINVAL;
167         }
168
169         writeb(BIN2BCD(tm->tm_sec),  base + S3C2410_RTCSEC);
170         writeb(BIN2BCD(tm->tm_min),  base + S3C2410_RTCMIN);
171         writeb(BIN2BCD(tm->tm_hour), base + S3C2410_RTCHOUR);
172         writeb(BIN2BCD(tm->tm_mday), base + S3C2410_RTCDATE);
173         writeb(BIN2BCD(tm->tm_mon + 1), base + S3C2410_RTCMON);
174         writeb(BIN2BCD(year), base + S3C2410_RTCYEAR);
175
176         return 0;
177 }
178
179 static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
180 {
181         struct rtc_time *alm_tm = &alrm->time;
182         void __iomem *base = s3c_rtc_base;
183         unsigned int alm_en;
184
185         alm_tm->tm_sec  = readb(base + S3C2410_ALMSEC);
186         alm_tm->tm_min  = readb(base + S3C2410_ALMMIN);
187         alm_tm->tm_hour = readb(base + S3C2410_ALMHOUR);
188         alm_tm->tm_mon  = readb(base + S3C2410_ALMMON);
189         alm_tm->tm_mday = readb(base + S3C2410_ALMDATE);
190         alm_tm->tm_year = readb(base + S3C2410_ALMYEAR);
191
192         alm_en = readb(base + S3C2410_RTCALM);
193
194         pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
195                  alm_en,
196                  alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
197                  alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
198
199
200         /* decode the alarm enable field */
201
202         if (alm_en & S3C2410_RTCALM_SECEN)
203                 BCD_TO_BIN(alm_tm->tm_sec);
204         else
205                 alm_tm->tm_sec = 0xff;
206
207         if (alm_en & S3C2410_RTCALM_MINEN)
208                 BCD_TO_BIN(alm_tm->tm_min);
209         else
210                 alm_tm->tm_min = 0xff;
211
212         if (alm_en & S3C2410_RTCALM_HOUREN)
213                 BCD_TO_BIN(alm_tm->tm_hour);
214         else
215                 alm_tm->tm_hour = 0xff;
216
217         if (alm_en & S3C2410_RTCALM_DAYEN)
218                 BCD_TO_BIN(alm_tm->tm_mday);
219         else
220                 alm_tm->tm_mday = 0xff;
221
222         if (alm_en & S3C2410_RTCALM_MONEN) {
223                 BCD_TO_BIN(alm_tm->tm_mon);
224                 alm_tm->tm_mon -= 1;
225         } else {
226                 alm_tm->tm_mon = 0xff;
227         }
228
229         if (alm_en & S3C2410_RTCALM_YEAREN)
230                 BCD_TO_BIN(alm_tm->tm_year);
231         else
232                 alm_tm->tm_year = 0xffff;
233
234         return 0;
235 }
236
237 static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
238 {
239         struct rtc_time *tm = &alrm->time;
240         void __iomem *base = s3c_rtc_base;
241         unsigned int alrm_en;
242
243         pr_debug("s3c_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
244                  alrm->enabled,
245                  tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
246                  tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);
247
248
249         alrm_en = readb(base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
250         writeb(0x00, base + S3C2410_RTCALM);
251
252         if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
253                 alrm_en |= S3C2410_RTCALM_SECEN;
254                 writeb(BIN2BCD(tm->tm_sec), base + S3C2410_ALMSEC);
255         }
256
257         if (tm->tm_min < 60 && tm->tm_min >= 0) {
258                 alrm_en |= S3C2410_RTCALM_MINEN;
259                 writeb(BIN2BCD(tm->tm_min), base + S3C2410_ALMMIN);
260         }
261
262         if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
263                 alrm_en |= S3C2410_RTCALM_HOUREN;
264                 writeb(BIN2BCD(tm->tm_hour), base + S3C2410_ALMHOUR);
265         }
266
267         pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
268
269         writeb(alrm_en, base + S3C2410_RTCALM);
270
271         if (0) {
272                 alrm_en = readb(base + S3C2410_RTCALM);
273                 alrm_en &= ~S3C2410_RTCALM_ALMEN;
274                 writeb(alrm_en, base + S3C2410_RTCALM);
275                 disable_irq_wake(s3c_rtc_alarmno);
276         }
277
278         if (alrm->enabled)
279                 enable_irq_wake(s3c_rtc_alarmno);
280         else
281                 disable_irq_wake(s3c_rtc_alarmno);
282
283         return 0;
284 }
285
286 static int s3c_rtc_ioctl(struct device *dev,
287                          unsigned int cmd, unsigned long arg)
288 {
289         unsigned int ret = -ENOIOCTLCMD;
290
291         switch (cmd) {
292         case RTC_AIE_OFF:
293         case RTC_AIE_ON:
294                 s3c_rtc_setaie((cmd == RTC_AIE_ON) ? 1 : 0);
295                 ret = 0;
296                 break;
297
298         case RTC_PIE_OFF:
299         case RTC_PIE_ON:
300                 tick_count = 0;
301                 s3c_rtc_setpie((cmd == RTC_PIE_ON) ? 1 : 0);
302                 ret = 0;
303                 break;
304
305         case RTC_IRQP_READ:
306                 ret = put_user(s3c_rtc_freq, (unsigned long __user *)arg);
307                 break;
308
309         case RTC_IRQP_SET:
310                 /* check for power of 2 */
311
312                 if ((arg & (arg-1)) != 0 || arg < 1) {
313                         ret = -EINVAL;
314                         goto exit;
315                 }
316
317                 pr_debug("s3c2410_rtc: setting frequency %ld\n", arg);
318
319                 s3c_rtc_setfreq(arg);
320                 ret = 0;
321                 break;
322
323         case RTC_UIE_ON:
324         case RTC_UIE_OFF:
325                 ret = -EINVAL;
326         }
327
328  exit:
329         return ret;
330 }
331
332 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
333 {
334         unsigned int rtcalm = readb(s3c_rtc_base + S3C2410_RTCALM);
335         unsigned int ticnt = readb(s3c_rtc_base + S3C2410_TICNT);
336
337         seq_printf(seq, "alarm_IRQ\t: %s\n",
338                    (rtcalm & S3C2410_RTCALM_ALMEN) ? "yes" : "no" );
339
340         seq_printf(seq, "periodic_IRQ\t: %s\n",
341                      (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" );
342
343         seq_printf(seq, "periodic_freq\t: %d\n", s3c_rtc_freq);
344
345         return 0;
346 }
347
348 static int s3c_rtc_open(struct device *dev)
349 {
350         struct platform_device *pdev = to_platform_device(dev);
351         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
352         int ret;
353
354         ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq,
355                           SA_INTERRUPT,  "s3c2410-rtc alarm", rtc_dev);
356
357         if (ret) {
358                 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret);
359                 return ret;
360         }
361
362         ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq,
363                           SA_INTERRUPT,  "s3c2410-rtc tick", rtc_dev);
364
365         if (ret) {
366                 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret);
367                 goto tick_err;
368         }
369
370         return ret;
371
372  tick_err:
373         free_irq(s3c_rtc_alarmno, rtc_dev);
374         return ret;
375 }
376
377 static void s3c_rtc_release(struct device *dev)
378 {
379         struct platform_device *pdev = to_platform_device(dev);
380         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
381
382         /* do not clear AIE here, it may be needed for wake */
383
384         s3c_rtc_setpie(0);
385         free_irq(s3c_rtc_alarmno, rtc_dev);
386         free_irq(s3c_rtc_tickno, rtc_dev);
387 }
388
389 static const struct rtc_class_ops s3c_rtcops = {
390         .open           = s3c_rtc_open,
391         .release        = s3c_rtc_release,
392         .ioctl          = s3c_rtc_ioctl,
393         .read_time      = s3c_rtc_gettime,
394         .set_time       = s3c_rtc_settime,
395         .read_alarm     = s3c_rtc_getalarm,
396         .set_alarm      = s3c_rtc_setalarm,
397         .proc           = s3c_rtc_proc,
398 };
399
400 static void s3c_rtc_enable(struct platform_device *pdev, int en)
401 {
402         void __iomem *base = s3c_rtc_base;
403         unsigned int tmp;
404
405         if (s3c_rtc_base == NULL)
406                 return;
407
408         if (!en) {
409                 tmp = readb(base + S3C2410_RTCCON);
410                 writeb(tmp & ~S3C2410_RTCCON_RTCEN, base + S3C2410_RTCCON);
411
412                 tmp = readb(base + S3C2410_TICNT);
413                 writeb(tmp & ~S3C2410_TICNT_ENABLE, base + S3C2410_TICNT);
414         } else {
415                 /* re-enable the device, and check it is ok */
416
417                 if ((readb(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){
418                         dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
419
420                         tmp = readb(base + S3C2410_RTCCON);
421                         writeb(tmp|S3C2410_RTCCON_RTCEN, base+S3C2410_RTCCON);
422                 }
423
424                 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){
425                         dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n");
426
427                         tmp = readb(base + S3C2410_RTCCON);
428                         writeb(tmp& ~S3C2410_RTCCON_CNTSEL, base+S3C2410_RTCCON);
429                 }
430
431                 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){
432                         dev_info(&pdev->dev, "removing RTCCON_CLKRST\n");
433
434                         tmp = readb(base + S3C2410_RTCCON);
435                         writeb(tmp & ~S3C2410_RTCCON_CLKRST, base+S3C2410_RTCCON);
436                 }
437         }
438 }
439
440 static int s3c_rtc_remove(struct platform_device *dev)
441 {
442         struct rtc_device *rtc = platform_get_drvdata(dev);
443
444         platform_set_drvdata(dev, NULL);
445         rtc_device_unregister(rtc);
446
447         s3c_rtc_setpie(0);
448         s3c_rtc_setaie(0);
449
450         iounmap(s3c_rtc_base);
451         release_resource(s3c_rtc_mem);
452         kfree(s3c_rtc_mem);
453
454         return 0;
455 }
456
457 static int s3c_rtc_probe(struct platform_device *pdev)
458 {
459         struct rtc_device *rtc;
460         struct resource *res;
461         int ret;
462
463         pr_debug("%s: probe=%p\n", __FUNCTION__, pdev);
464
465         /* find the IRQs */
466
467         s3c_rtc_tickno = platform_get_irq(pdev, 1);
468         if (s3c_rtc_tickno < 0) {
469                 dev_err(&pdev->dev, "no irq for rtc tick\n");
470                 return -ENOENT;
471         }
472
473         s3c_rtc_alarmno = platform_get_irq(pdev, 0);
474         if (s3c_rtc_alarmno < 0) {
475                 dev_err(&pdev->dev, "no irq for alarm\n");
476                 return -ENOENT;
477         }
478
479         pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
480                  s3c_rtc_tickno, s3c_rtc_alarmno);
481
482         /* get the memory region */
483
484         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
485         if (res == NULL) {
486                 dev_err(&pdev->dev, "failed to get memory region resource\n");
487                 return -ENOENT;
488         }
489
490         s3c_rtc_mem = request_mem_region(res->start,
491                                          res->end-res->start+1,
492                                          pdev->name);
493
494         if (s3c_rtc_mem == NULL) {
495                 dev_err(&pdev->dev, "failed to reserve memory region\n");
496                 ret = -ENOENT;
497                 goto err_nores;
498         }
499
500         s3c_rtc_base = ioremap(res->start, res->end - res->start + 1);
501         if (s3c_rtc_base == NULL) {
502                 dev_err(&pdev->dev, "failed ioremap()\n");
503                 ret = -EINVAL;
504                 goto err_nomap;
505         }
506
507         /* check to see if everything is setup correctly */
508
509         s3c_rtc_enable(pdev, 1);
510
511         pr_debug("s3c2410_rtc: RTCCON=%02x\n",
512                  readb(s3c_rtc_base + S3C2410_RTCCON));
513
514         s3c_rtc_setfreq(s3c_rtc_freq);
515
516         /* register RTC and exit */
517
518         rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops,
519                                   THIS_MODULE);
520
521         if (IS_ERR(rtc)) {
522                 dev_err(&pdev->dev, "cannot attach rtc\n");
523                 ret = PTR_ERR(rtc);
524                 goto err_nortc;
525         }
526
527         rtc->max_user_freq = 128;
528
529         platform_set_drvdata(pdev, rtc);
530         return 0;
531
532  err_nortc:
533         s3c_rtc_enable(pdev, 0);
534         iounmap(s3c_rtc_base);
535
536  err_nomap:
537         release_resource(s3c_rtc_mem);
538
539  err_nores:
540         return ret;
541 }
542
543 #ifdef CONFIG_PM
544
545 /* RTC Power management control */
546
547 static struct timespec s3c_rtc_delta;
548
549 static int ticnt_save;
550
551 static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state)
552 {
553         struct rtc_time tm;
554         struct timespec time;
555
556         time.tv_nsec = 0;
557
558         /* save TICNT for anyone using periodic interrupts */
559
560         ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT);
561
562         /* calculate time delta for suspend */
563
564         s3c_rtc_gettime(&pdev->dev, &tm);
565         rtc_tm_to_time(&tm, &time.tv_sec);
566         save_time_delta(&s3c_rtc_delta, &time);
567         s3c_rtc_enable(pdev, 0);
568
569         return 0;
570 }
571
572 static int s3c_rtc_resume(struct platform_device *pdev)
573 {
574         struct rtc_time tm;
575         struct timespec time;
576
577         time.tv_nsec = 0;
578
579         s3c_rtc_enable(pdev, 1);
580         s3c_rtc_gettime(&pdev->dev, &tm);
581         rtc_tm_to_time(&tm, &time.tv_sec);
582         restore_time_delta(&s3c_rtc_delta, &time);
583
584         writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT);
585         return 0;
586 }
587 #else
588 #define s3c_rtc_suspend NULL
589 #define s3c_rtc_resume  NULL
590 #endif
591
592 static struct platform_driver s3c2410_rtcdrv = {
593         .probe          = s3c_rtc_probe,
594         .remove         = s3c_rtc_remove,
595         .suspend        = s3c_rtc_suspend,
596         .resume         = s3c_rtc_resume,
597         .driver         = {
598                 .name   = "s3c2410-rtc",
599                 .owner  = THIS_MODULE,
600         },
601 };
602
603 static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n";
604
605 static int __init s3c_rtc_init(void)
606 {
607         printk(banner);
608         return platform_driver_register(&s3c2410_rtcdrv);
609 }
610
611 static void __exit s3c_rtc_exit(void)
612 {
613         platform_driver_unregister(&s3c2410_rtcdrv);
614 }
615
616 module_init(s3c_rtc_init);
617 module_exit(s3c_rtc_exit);
618
619 MODULE_DESCRIPTION("Samsung S3C RTC Driver");
620 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
621 MODULE_LICENSE("GPL");