e1a90d9a8756711bfc5c85a7fb87b19f1efe9d6a
[linux-2.6.git] / drivers / char / s3c2410-rtc.c
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 int 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         return 0;
156 }
157
158
159 static int s3c2410_rtc_settime(struct rtc_time *tm)
160 {
161         /* the rtc gets round the y2k problem by just not supporting it */
162
163         if (tm->tm_year < 100)
164                 return -EINVAL;
165
166         writeb(BIN2BCD(tm->tm_sec),  S3C2410_RTCSEC);
167         writeb(BIN2BCD(tm->tm_min),  S3C2410_RTCMIN);
168         writeb(BIN2BCD(tm->tm_hour), S3C2410_RTCHOUR);
169         writeb(BIN2BCD(tm->tm_mday), S3C2410_RTCDATE);
170         writeb(BIN2BCD(tm->tm_mon + 1), S3C2410_RTCMON);
171         writeb(BIN2BCD(tm->tm_year - 100), S3C2410_RTCYEAR);
172
173         return 0;
174 }
175
176 static int s3c2410_rtc_getalarm(struct rtc_wkalrm *alrm)
177 {
178         struct rtc_time *alm_tm = &alrm->time;
179         unsigned int alm_en;
180
181         alm_tm->tm_sec  = readb(S3C2410_ALMSEC);
182         alm_tm->tm_min  = readb(S3C2410_ALMMIN);
183         alm_tm->tm_hour = readb(S3C2410_ALMHOUR);
184         alm_tm->tm_mon  = readb(S3C2410_ALMMON);
185         alm_tm->tm_mday = readb(S3C2410_ALMDATE);
186         alm_tm->tm_year = readb(S3C2410_ALMYEAR);
187
188         alm_en = readb(S3C2410_RTCALM);
189
190         pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
191                  alm_en,
192                  alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
193                  alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
194
195
196         /* decode the alarm enable field */
197
198         if (alm_en & S3C2410_RTCALM_SECEN) {
199                 BCD_TO_BIN(alm_tm->tm_sec);
200         } else {
201                 alm_tm->tm_sec = 0xff;
202         }
203
204         if (alm_en & S3C2410_RTCALM_MINEN) {
205                 BCD_TO_BIN(alm_tm->tm_min);
206         } else {
207                 alm_tm->tm_min = 0xff;
208         }
209
210         if (alm_en & S3C2410_RTCALM_HOUREN) {
211                 BCD_TO_BIN(alm_tm->tm_hour);
212         } else {
213                 alm_tm->tm_hour = 0xff;
214         }
215
216         if (alm_en & S3C2410_RTCALM_DAYEN) {
217                 BCD_TO_BIN(alm_tm->tm_mday);
218         } else {
219                 alm_tm->tm_mday = 0xff;
220         }
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
235         /* todo - set alrm->enabled ? */
236
237         return 0;
238 }
239
240 static int s3c2410_rtc_setalarm(struct rtc_wkalrm *alrm)
241 {
242         struct rtc_time *tm = &alrm->time;
243         unsigned int alrm_en;
244
245         pr_debug("s3c2410_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
246                  alrm->enabled,
247                  tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
248                  tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);
249
250         if (alrm->enabled || 1) {
251                 alrm_en = readb(S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
252                 writeb(0x00, S3C2410_RTCALM);
253
254                 if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
255                         alrm_en |= S3C2410_RTCALM_SECEN;
256                         writeb(BIN2BCD(tm->tm_sec), S3C2410_ALMSEC);
257                 }
258
259                 if (tm->tm_min < 60 && tm->tm_min >= 0) {
260                         alrm_en |= S3C2410_RTCALM_MINEN;
261                         writeb(BIN2BCD(tm->tm_min), S3C2410_ALMMIN);
262                 }
263
264                 if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
265                         alrm_en |= S3C2410_RTCALM_HOUREN;
266                         writeb(BIN2BCD(tm->tm_hour), S3C2410_ALMHOUR);
267                 }
268
269                 pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
270
271                 writeb(alrm_en, S3C2410_RTCALM);
272                 enable_irq_wake(s3c2410_rtc_alarmno);
273         } else {
274                 alrm_en = readb(S3C2410_RTCALM);
275                 alrm_en &= ~S3C2410_RTCALM_ALMEN;
276                 writeb(alrm_en, S3C2410_RTCALM);
277                 disable_irq_wake(s3c2410_rtc_alarmno);
278         }
279
280         return 0;
281 }
282
283 static int s3c2410_rtc_ioctl(unsigned int cmd, unsigned long arg)
284 {
285         switch (cmd) {
286         case RTC_AIE_OFF:
287         case RTC_AIE_ON:
288                 s3c2410_rtc_setaie((cmd == RTC_AIE_ON) ? 1 : 0);
289                 return 0;
290
291         case RTC_PIE_OFF:
292         case RTC_PIE_ON:
293                 s3c2410_rtc_setpie((cmd == RTC_PIE_ON) ? 1 : 0);
294                 return 0;
295
296         case RTC_IRQP_READ:
297                 return put_user(s3c2410_rtc_freq, (unsigned long __user *)arg);
298
299         case RTC_IRQP_SET:
300                 if (arg < 1 || arg > 64)
301                         return -EINVAL;
302
303                 if (!capable(CAP_SYS_RESOURCE))
304                         return -EACCES;
305
306                 /* check for power of 2 */
307
308                 if ((arg & (arg-1)) != 0)
309                         return -EINVAL;
310
311                 pr_debug("s3c2410_rtc: setting frequency %ld\n", arg);
312
313                 s3c2410_rtc_setfreq(arg);
314                 return 0;
315
316         case RTC_UIE_ON:
317         case RTC_UIE_OFF:
318                 return -EINVAL;
319         }
320
321         return -EINVAL;
322 }
323
324 static int s3c2410_rtc_proc(char *buf)
325 {
326         unsigned int rtcalm = readb(S3C2410_RTCALM);
327         unsigned int ticnt = readb (S3C2410_TICNT);
328         char *p = buf;
329
330         p += sprintf(p, "alarm_IRQ\t: %s\n",
331                      (rtcalm & S3C2410_RTCALM_ALMEN) ? "yes" : "no" );
332         p += sprintf(p, "periodic_IRQ\t: %s\n",
333                      (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" );
334         p += sprintf(p, "periodic_freq\t: %d\n", s3c2410_rtc_freq);
335
336         return p - buf;
337 }
338
339 static int s3c2410_rtc_open(void)
340 {
341         int ret;
342
343         ret = request_irq(s3c2410_rtc_alarmno, s3c2410_rtc_alarmirq,
344                           SA_INTERRUPT,  "s3c2410-rtc alarm", NULL);
345
346         if (ret)
347                 printk(KERN_ERR "IRQ%d already in use\n", s3c2410_rtc_alarmno);
348
349         ret = request_irq(s3c2410_rtc_tickno, s3c2410_rtc_tickirq,
350                           SA_INTERRUPT,  "s3c2410-rtc tick", NULL);
351
352         if (ret) {
353                 printk(KERN_ERR "IRQ%d already in use\n", s3c2410_rtc_tickno);
354                 goto tick_err;
355         }
356
357         return ret;
358
359  tick_err:
360         free_irq(s3c2410_rtc_alarmno, NULL);
361         return ret;
362 }
363
364 static void s3c2410_rtc_release(void)
365 {
366         /* do not clear AIE here, it may be needed for wake */
367
368         s3c2410_rtc_setpie(0);
369         free_irq(s3c2410_rtc_alarmno, NULL);
370         free_irq(s3c2410_rtc_tickno, NULL);
371 }
372
373 static struct rtc_ops s3c2410_rtcops = {
374         .owner          = THIS_MODULE,
375         .open           = s3c2410_rtc_open,
376         .release        = s3c2410_rtc_release,
377         .ioctl          = s3c2410_rtc_ioctl,
378         .read_time      = s3c2410_rtc_gettime,
379         .set_time       = s3c2410_rtc_settime,
380         .read_alarm     = s3c2410_rtc_getalarm,
381         .set_alarm      = s3c2410_rtc_setalarm,
382         .proc           = s3c2410_rtc_proc,
383 };
384
385 static void s3c2410_rtc_enable(struct device *dev, int en)
386 {
387         unsigned int tmp;
388
389         if (s3c2410_rtc_base == NULL)
390                 return;
391
392         if (!en) {
393                 tmp = readb(S3C2410_RTCCON);
394                 writeb(tmp & ~S3C2410_RTCCON_RTCEN, S3C2410_RTCCON);
395
396                 tmp = readb(S3C2410_TICNT);
397                 writeb(tmp & ~S3C2410_TICNT_ENABLE, S3C2410_TICNT);
398         } else {
399                 /* re-enable the device, and check it is ok */
400
401                 if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){
402                         dev_info(dev, "rtc disabled, re-enabling\n");
403
404                         tmp = readb(S3C2410_RTCCON);
405                         writeb(tmp | S3C2410_RTCCON_RTCEN , S3C2410_RTCCON);
406                 }
407
408                 if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){
409                         dev_info(dev, "removing S3C2410_RTCCON_CNTSEL\n");
410
411                         tmp = readb(S3C2410_RTCCON);
412                         writeb(tmp& ~S3C2410_RTCCON_CNTSEL , S3C2410_RTCCON);
413                 }
414
415                 if ((readb(S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){
416                         dev_info(dev, "removing S3C2410_RTCCON_CLKRST\n");
417
418                         tmp = readb(S3C2410_RTCCON);
419                         writeb(tmp & ~S3C2410_RTCCON_CLKRST, S3C2410_RTCCON);
420                 }
421         }
422 }
423
424 static int s3c2410_rtc_remove(struct device *dev)
425 {
426         unregister_rtc(&s3c2410_rtcops);
427
428         s3c2410_rtc_setpie(0);
429         s3c2410_rtc_setaie(0);
430
431         if (s3c2410_rtc_mem != NULL) {
432                 pr_debug("s3c2410_rtc: releasing s3c2410_rtc_mem\n");
433                 iounmap(s3c2410_rtc_base);
434                 release_resource(s3c2410_rtc_mem);
435                 kfree(s3c2410_rtc_mem);
436         }
437
438         return 0;
439 }
440
441 static int s3c2410_rtc_probe(struct device *dev)
442 {
443         struct platform_device *pdev = to_platform_device(dev);
444         struct resource *res;
445         int ret;
446
447         pr_debug("%s: probe=%p, device=%p\n", __FUNCTION__, pdev, dev);
448
449         /* find the IRQs */
450
451         s3c2410_rtc_tickno = platform_get_irq(pdev, 1);
452         if (s3c2410_rtc_tickno <= 0) {
453                 dev_err(dev, "no irq for rtc tick\n");
454                 return -ENOENT;
455         }
456
457         s3c2410_rtc_alarmno = platform_get_irq(pdev, 0);
458         if (s3c2410_rtc_alarmno <= 0) {
459                 dev_err(dev, "no irq for alarm\n");
460                 return -ENOENT;
461         }
462
463         pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
464                  s3c2410_rtc_tickno, s3c2410_rtc_alarmno);
465
466         /* get the memory region */
467
468         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
469         if (res == NULL) {
470                 dev_err(dev, "failed to get memory region resource\n");
471                 return -ENOENT;
472         }
473
474         s3c2410_rtc_mem = request_mem_region(res->start, res->end-res->start+1,
475                                      pdev->name);
476
477         if (s3c2410_rtc_mem == NULL) {
478                 dev_err(dev, "failed to reserve memory region\n");
479                 ret = -ENOENT;
480                 goto exit_err;
481         }
482
483         s3c2410_rtc_base = ioremap(res->start, res->end - res->start + 1);
484         if (s3c2410_rtc_base == NULL) {
485                 dev_err(dev, "failed ioremap()\n");
486                 ret = -EINVAL;
487                 goto exit_err;
488         }
489
490         s3c2410_rtc_mem = res;
491         pr_debug("s3c2410_rtc_base=%p\n", s3c2410_rtc_base);
492
493         pr_debug("s3c2410_rtc: RTCCON=%02x\n", readb(S3C2410_RTCCON));
494
495         /* check to see if everything is setup correctly */
496
497         s3c2410_rtc_enable(dev, 1);
498
499         pr_debug("s3c2410_rtc: RTCCON=%02x\n", readb(S3C2410_RTCCON));
500
501         s3c2410_rtc_setfreq(s3c2410_rtc_freq);
502
503         /* register RTC and exit */
504
505         register_rtc(&s3c2410_rtcops);
506         return 0;
507
508  exit_err:
509         dev_err(dev, "error %d during initialisation\n", ret);
510
511         return ret;
512 }
513
514 #ifdef CONFIG_PM
515
516 /* S3C2410 RTC Power management control */
517
518 static struct timespec s3c2410_rtc_delta;
519
520 static int ticnt_save;
521
522 static int s3c2410_rtc_suspend(struct device *dev, pm_message_t state, u32 level)
523 {
524         struct rtc_time tm;
525         struct timespec time;
526
527         time.tv_nsec = 0;
528
529         if (level == SUSPEND_POWER_DOWN) {
530                 /* save TICNT for anyone using periodic interrupts */
531
532                 ticnt_save = readb(S3C2410_TICNT);
533
534                 /* calculate time delta for suspend */
535
536                 s3c2410_rtc_gettime(&tm);
537                 rtc_tm_to_time(&tm, &time.tv_sec);
538                 save_time_delta(&s3c2410_rtc_delta, &time);
539                 s3c2410_rtc_enable(dev, 0);
540         }
541
542         return 0;
543 }
544
545 static int s3c2410_rtc_resume(struct device *dev, u32 level)
546 {
547         struct rtc_time tm;
548         struct timespec time;
549
550         time.tv_nsec = 0;
551
552         s3c2410_rtc_enable(dev, 1);
553         s3c2410_rtc_gettime(&tm);
554         rtc_tm_to_time(&tm, &time.tv_sec);
555         restore_time_delta(&s3c2410_rtc_delta, &time);
556
557         writeb(ticnt_save, S3C2410_TICNT);
558         return 0;
559 }
560 #else
561 #define s3c2410_rtc_suspend NULL
562 #define s3c2410_rtc_resume  NULL
563 #endif
564
565 static struct device_driver s3c2410_rtcdrv = {
566         .name           = "s3c2410-rtc",
567         .owner          = THIS_MODULE,
568         .bus            = &platform_bus_type,
569         .probe          = s3c2410_rtc_probe,
570         .remove         = s3c2410_rtc_remove,
571         .suspend        = s3c2410_rtc_suspend,
572         .resume         = s3c2410_rtc_resume,
573 };
574
575 static char __initdata banner[] = "S3C2410 RTC, (c) 2004 Simtec Electronics\n";
576
577 static int __init s3c2410_rtc_init(void)
578 {
579         printk(banner);
580         return driver_register(&s3c2410_rtcdrv);
581 }
582
583 static void __exit s3c2410_rtc_exit(void)
584 {
585         driver_unregister(&s3c2410_rtcdrv);
586 }
587
588 module_init(s3c2410_rtc_init);
589 module_exit(s3c2410_rtc_exit);
590
591 MODULE_DESCRIPTION("S3C24XX RTC Driver");
592 MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
593 MODULE_LICENSE("GPL");