Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[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 #include <linux/log2.h>
24
25 #include <mach/hardware.h>
26 #include <asm/uaccess.h>
27 #include <asm/io.h>
28 #include <asm/irq.h>
29 #include <asm/plat-s3c/regs-rtc.h>
30
31 /* I have yet to find an S3C implementation with more than one
32  * of these rtc blocks in */
33
34 static struct resource *s3c_rtc_mem;
35
36 static void __iomem *s3c_rtc_base;
37 static int s3c_rtc_alarmno = NO_IRQ;
38 static int s3c_rtc_tickno  = NO_IRQ;
39
40 static DEFINE_SPINLOCK(s3c_rtc_pie_lock);
41
42 /* IRQ Handlers */
43
44 static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
45 {
46         struct rtc_device *rdev = id;
47
48         rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
49         return IRQ_HANDLED;
50 }
51
52 static irqreturn_t s3c_rtc_tickirq(int irq, void *id)
53 {
54         struct rtc_device *rdev = id;
55
56         rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF);
57         return IRQ_HANDLED;
58 }
59
60 /* Update control registers */
61 static void s3c_rtc_setaie(int to)
62 {
63         unsigned int tmp;
64
65         pr_debug("%s: aie=%d\n", __func__, to);
66
67         tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
68
69         if (to)
70                 tmp |= S3C2410_RTCALM_ALMEN;
71
72         writeb(tmp, s3c_rtc_base + S3C2410_RTCALM);
73 }
74
75 static int s3c_rtc_setpie(struct device *dev, int enabled)
76 {
77         unsigned int tmp;
78
79         pr_debug("%s: pie=%d\n", __func__, enabled);
80
81         spin_lock_irq(&s3c_rtc_pie_lock);
82         tmp = readb(s3c_rtc_base + S3C2410_TICNT) & ~S3C2410_TICNT_ENABLE;
83
84         if (enabled)
85                 tmp |= S3C2410_TICNT_ENABLE;
86
87         writeb(tmp, s3c_rtc_base + S3C2410_TICNT);
88         spin_unlock_irq(&s3c_rtc_pie_lock);
89
90         return 0;
91 }
92
93 static int s3c_rtc_setfreq(struct device *dev, int freq)
94 {
95         unsigned int tmp;
96
97         spin_lock_irq(&s3c_rtc_pie_lock);
98
99         tmp = readb(s3c_rtc_base + S3C2410_TICNT) & S3C2410_TICNT_ENABLE;
100         tmp |= (128 / freq)-1;
101
102         writeb(tmp, s3c_rtc_base + S3C2410_TICNT);
103         spin_unlock_irq(&s3c_rtc_pie_lock);
104
105         return 0;
106 }
107
108 /* Time read/write */
109
110 static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
111 {
112         unsigned int have_retried = 0;
113         void __iomem *base = s3c_rtc_base;
114
115  retry_get_time:
116         rtc_tm->tm_min  = readb(base + S3C2410_RTCMIN);
117         rtc_tm->tm_hour = readb(base + S3C2410_RTCHOUR);
118         rtc_tm->tm_mday = readb(base + S3C2410_RTCDATE);
119         rtc_tm->tm_mon  = readb(base + S3C2410_RTCMON);
120         rtc_tm->tm_year = readb(base + S3C2410_RTCYEAR);
121         rtc_tm->tm_sec  = readb(base + S3C2410_RTCSEC);
122
123         /* the only way to work out wether the system was mid-update
124          * when we read it is to check the second counter, and if it
125          * is zero, then we re-try the entire read
126          */
127
128         if (rtc_tm->tm_sec == 0 && !have_retried) {
129                 have_retried = 1;
130                 goto retry_get_time;
131         }
132
133         pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n",
134                  rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
135                  rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
136
137         BCD_TO_BIN(rtc_tm->tm_sec);
138         BCD_TO_BIN(rtc_tm->tm_min);
139         BCD_TO_BIN(rtc_tm->tm_hour);
140         BCD_TO_BIN(rtc_tm->tm_mday);
141         BCD_TO_BIN(rtc_tm->tm_mon);
142         BCD_TO_BIN(rtc_tm->tm_year);
143
144         rtc_tm->tm_year += 100;
145         rtc_tm->tm_mon -= 1;
146
147         return 0;
148 }
149
150 static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
151 {
152         void __iomem *base = s3c_rtc_base;
153         int year = tm->tm_year - 100;
154
155         pr_debug("set time %02d.%02d.%02d %02d/%02d/%02d\n",
156                  tm->tm_year, tm->tm_mon, tm->tm_mday,
157                  tm->tm_hour, tm->tm_min, tm->tm_sec);
158
159         /* we get around y2k by simply not supporting it */
160
161         if (year < 0 || year >= 100) {
162                 dev_err(dev, "rtc only supports 100 years\n");
163                 return -EINVAL;
164         }
165
166         writeb(BIN2BCD(tm->tm_sec),  base + S3C2410_RTCSEC);
167         writeb(BIN2BCD(tm->tm_min),  base + S3C2410_RTCMIN);
168         writeb(BIN2BCD(tm->tm_hour), base + S3C2410_RTCHOUR);
169         writeb(BIN2BCD(tm->tm_mday), base + S3C2410_RTCDATE);
170         writeb(BIN2BCD(tm->tm_mon + 1), base + S3C2410_RTCMON);
171         writeb(BIN2BCD(year), base + S3C2410_RTCYEAR);
172
173         return 0;
174 }
175
176 static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
177 {
178         struct rtc_time *alm_tm = &alrm->time;
179         void __iomem *base = s3c_rtc_base;
180         unsigned int alm_en;
181
182         alm_tm->tm_sec  = readb(base + S3C2410_ALMSEC);
183         alm_tm->tm_min  = readb(base + S3C2410_ALMMIN);
184         alm_tm->tm_hour = readb(base + S3C2410_ALMHOUR);
185         alm_tm->tm_mon  = readb(base + S3C2410_ALMMON);
186         alm_tm->tm_mday = readb(base + S3C2410_ALMDATE);
187         alm_tm->tm_year = readb(base + S3C2410_ALMYEAR);
188
189         alm_en = readb(base + S3C2410_RTCALM);
190
191         alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;
192
193         pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
194                  alm_en,
195                  alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
196                  alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
197
198
199         /* decode the alarm enable field */
200
201         if (alm_en & S3C2410_RTCALM_SECEN)
202                 BCD_TO_BIN(alm_tm->tm_sec);
203         else
204                 alm_tm->tm_sec = 0xff;
205
206         if (alm_en & S3C2410_RTCALM_MINEN)
207                 BCD_TO_BIN(alm_tm->tm_min);
208         else
209                 alm_tm->tm_min = 0xff;
210
211         if (alm_en & S3C2410_RTCALM_HOUREN)
212                 BCD_TO_BIN(alm_tm->tm_hour);
213         else
214                 alm_tm->tm_hour = 0xff;
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         if (alm_en & S3C2410_RTCALM_MONEN) {
222                 BCD_TO_BIN(alm_tm->tm_mon);
223                 alm_tm->tm_mon -= 1;
224         } else {
225                 alm_tm->tm_mon = 0xff;
226         }
227
228         if (alm_en & S3C2410_RTCALM_YEAREN)
229                 BCD_TO_BIN(alm_tm->tm_year);
230         else
231                 alm_tm->tm_year = 0xffff;
232
233         return 0;
234 }
235
236 static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
237 {
238         struct rtc_time *tm = &alrm->time;
239         void __iomem *base = s3c_rtc_base;
240         unsigned int alrm_en;
241
242         pr_debug("s3c_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
243                  alrm->enabled,
244                  tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
245                  tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);
246
247
248         alrm_en = readb(base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
249         writeb(0x00, base + S3C2410_RTCALM);
250
251         if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
252                 alrm_en |= S3C2410_RTCALM_SECEN;
253                 writeb(BIN2BCD(tm->tm_sec), base + S3C2410_ALMSEC);
254         }
255
256         if (tm->tm_min < 60 && tm->tm_min >= 0) {
257                 alrm_en |= S3C2410_RTCALM_MINEN;
258                 writeb(BIN2BCD(tm->tm_min), base + S3C2410_ALMMIN);
259         }
260
261         if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
262                 alrm_en |= S3C2410_RTCALM_HOUREN;
263                 writeb(BIN2BCD(tm->tm_hour), base + S3C2410_ALMHOUR);
264         }
265
266         pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
267
268         writeb(alrm_en, base + S3C2410_RTCALM);
269
270         s3c_rtc_setaie(alrm->enabled);
271
272         if (alrm->enabled)
273                 enable_irq_wake(s3c_rtc_alarmno);
274         else
275                 disable_irq_wake(s3c_rtc_alarmno);
276
277         return 0;
278 }
279
280 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
281 {
282         unsigned int ticnt = readb(s3c_rtc_base + S3C2410_TICNT);
283
284         seq_printf(seq, "periodic_IRQ\t: %s\n",
285                      (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" );
286         return 0;
287 }
288
289 static int s3c_rtc_open(struct device *dev)
290 {
291         struct platform_device *pdev = to_platform_device(dev);
292         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
293         int ret;
294
295         ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq,
296                           IRQF_DISABLED,  "s3c2410-rtc alarm", rtc_dev);
297
298         if (ret) {
299                 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret);
300                 return ret;
301         }
302
303         ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq,
304                           IRQF_DISABLED,  "s3c2410-rtc tick", rtc_dev);
305
306         if (ret) {
307                 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret);
308                 goto tick_err;
309         }
310
311         return ret;
312
313  tick_err:
314         free_irq(s3c_rtc_alarmno, rtc_dev);
315         return ret;
316 }
317
318 static void s3c_rtc_release(struct device *dev)
319 {
320         struct platform_device *pdev = to_platform_device(dev);
321         struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
322
323         /* do not clear AIE here, it may be needed for wake */
324
325         s3c_rtc_setpie(dev, 0);
326         free_irq(s3c_rtc_alarmno, rtc_dev);
327         free_irq(s3c_rtc_tickno, rtc_dev);
328 }
329
330 static const struct rtc_class_ops s3c_rtcops = {
331         .open           = s3c_rtc_open,
332         .release        = s3c_rtc_release,
333         .read_time      = s3c_rtc_gettime,
334         .set_time       = s3c_rtc_settime,
335         .read_alarm     = s3c_rtc_getalarm,
336         .set_alarm      = s3c_rtc_setalarm,
337         .irq_set_freq   = s3c_rtc_setfreq,
338         .irq_set_state  = s3c_rtc_setpie,
339         .proc           = s3c_rtc_proc,
340 };
341
342 static void s3c_rtc_enable(struct platform_device *pdev, int en)
343 {
344         void __iomem *base = s3c_rtc_base;
345         unsigned int tmp;
346
347         if (s3c_rtc_base == NULL)
348                 return;
349
350         if (!en) {
351                 tmp = readb(base + S3C2410_RTCCON);
352                 writeb(tmp & ~S3C2410_RTCCON_RTCEN, base + S3C2410_RTCCON);
353
354                 tmp = readb(base + S3C2410_TICNT);
355                 writeb(tmp & ~S3C2410_TICNT_ENABLE, base + S3C2410_TICNT);
356         } else {
357                 /* re-enable the device, and check it is ok */
358
359                 if ((readb(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){
360                         dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
361
362                         tmp = readb(base + S3C2410_RTCCON);
363                         writeb(tmp|S3C2410_RTCCON_RTCEN, base+S3C2410_RTCCON);
364                 }
365
366                 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){
367                         dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n");
368
369                         tmp = readb(base + S3C2410_RTCCON);
370                         writeb(tmp& ~S3C2410_RTCCON_CNTSEL, base+S3C2410_RTCCON);
371                 }
372
373                 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){
374                         dev_info(&pdev->dev, "removing RTCCON_CLKRST\n");
375
376                         tmp = readb(base + S3C2410_RTCCON);
377                         writeb(tmp & ~S3C2410_RTCCON_CLKRST, base+S3C2410_RTCCON);
378                 }
379         }
380 }
381
382 static int __devexit s3c_rtc_remove(struct platform_device *dev)
383 {
384         struct rtc_device *rtc = platform_get_drvdata(dev);
385
386         platform_set_drvdata(dev, NULL);
387         rtc_device_unregister(rtc);
388
389         s3c_rtc_setpie(&dev->dev, 0);
390         s3c_rtc_setaie(0);
391
392         iounmap(s3c_rtc_base);
393         release_resource(s3c_rtc_mem);
394         kfree(s3c_rtc_mem);
395
396         return 0;
397 }
398
399 static int __devinit s3c_rtc_probe(struct platform_device *pdev)
400 {
401         struct rtc_device *rtc;
402         struct resource *res;
403         int ret;
404
405         pr_debug("%s: probe=%p\n", __func__, pdev);
406
407         /* find the IRQs */
408
409         s3c_rtc_tickno = platform_get_irq(pdev, 1);
410         if (s3c_rtc_tickno < 0) {
411                 dev_err(&pdev->dev, "no irq for rtc tick\n");
412                 return -ENOENT;
413         }
414
415         s3c_rtc_alarmno = platform_get_irq(pdev, 0);
416         if (s3c_rtc_alarmno < 0) {
417                 dev_err(&pdev->dev, "no irq for alarm\n");
418                 return -ENOENT;
419         }
420
421         pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
422                  s3c_rtc_tickno, s3c_rtc_alarmno);
423
424         /* get the memory region */
425
426         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
427         if (res == NULL) {
428                 dev_err(&pdev->dev, "failed to get memory region resource\n");
429                 return -ENOENT;
430         }
431
432         s3c_rtc_mem = request_mem_region(res->start,
433                                          res->end-res->start+1,
434                                          pdev->name);
435
436         if (s3c_rtc_mem == NULL) {
437                 dev_err(&pdev->dev, "failed to reserve memory region\n");
438                 ret = -ENOENT;
439                 goto err_nores;
440         }
441
442         s3c_rtc_base = ioremap(res->start, res->end - res->start + 1);
443         if (s3c_rtc_base == NULL) {
444                 dev_err(&pdev->dev, "failed ioremap()\n");
445                 ret = -EINVAL;
446                 goto err_nomap;
447         }
448
449         /* check to see if everything is setup correctly */
450
451         s3c_rtc_enable(pdev, 1);
452
453         pr_debug("s3c2410_rtc: RTCCON=%02x\n",
454                  readb(s3c_rtc_base + S3C2410_RTCCON));
455
456         s3c_rtc_setfreq(&pdev->dev, 1);
457
458         /* register RTC and exit */
459
460         rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops,
461                                   THIS_MODULE);
462
463         if (IS_ERR(rtc)) {
464                 dev_err(&pdev->dev, "cannot attach rtc\n");
465                 ret = PTR_ERR(rtc);
466                 goto err_nortc;
467         }
468
469         rtc->max_user_freq = 128;
470
471         platform_set_drvdata(pdev, rtc);
472         return 0;
473
474  err_nortc:
475         s3c_rtc_enable(pdev, 0);
476         iounmap(s3c_rtc_base);
477
478  err_nomap:
479         release_resource(s3c_rtc_mem);
480
481  err_nores:
482         return ret;
483 }
484
485 #ifdef CONFIG_PM
486
487 /* RTC Power management control */
488
489 static int ticnt_save;
490
491 static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state)
492 {
493         /* save TICNT for anyone using periodic interrupts */
494         ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT);
495         s3c_rtc_enable(pdev, 0);
496         return 0;
497 }
498
499 static int s3c_rtc_resume(struct platform_device *pdev)
500 {
501         s3c_rtc_enable(pdev, 1);
502         writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT);
503         return 0;
504 }
505 #else
506 #define s3c_rtc_suspend NULL
507 #define s3c_rtc_resume  NULL
508 #endif
509
510 static struct platform_driver s3c2410_rtcdrv = {
511         .probe          = s3c_rtc_probe,
512         .remove         = __devexit_p(s3c_rtc_remove),
513         .suspend        = s3c_rtc_suspend,
514         .resume         = s3c_rtc_resume,
515         .driver         = {
516                 .name   = "s3c2410-rtc",
517                 .owner  = THIS_MODULE,
518         },
519 };
520
521 static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n";
522
523 static int __init s3c_rtc_init(void)
524 {
525         printk(banner);
526         return platform_driver_register(&s3c2410_rtcdrv);
527 }
528
529 static void __exit s3c_rtc_exit(void)
530 {
531         platform_driver_unregister(&s3c2410_rtcdrv);
532 }
533
534 module_init(s3c_rtc_init);
535 module_exit(s3c_rtc_exit);
536
537 MODULE_DESCRIPTION("Samsung S3C RTC Driver");
538 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
539 MODULE_LICENSE("GPL");
540 MODULE_ALIAS("platform:s3c2410-rtc");