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path: root/drivers/rtc/rtc-s3c.c
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-rw-r--r--drivers/rtc/rtc-s3c.c607
1 files changed, 607 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c
new file mode 100644
index 000000000000..d6d1bff52b8e
--- /dev/null
+++ b/drivers/rtc/rtc-s3c.c
@@ -0,0 +1,607 @@
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
37static struct resource *s3c_rtc_mem;
38
39static void __iomem *s3c_rtc_base;
40static int s3c_rtc_alarmno = NO_IRQ;
41static int s3c_rtc_tickno = NO_IRQ;
42static int s3c_rtc_freq = 1;
43
44static DEFINE_SPINLOCK(s3c_rtc_pie_lock);
45static unsigned int tick_count;
46
47/* IRQ Handlers */
48
49static 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
57static 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 */
66static 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
80static 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
96static 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
113static 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
152static 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
169static 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
226static 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
274static 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
320static 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
336static 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
365static 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
377static 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
388static 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
427static 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
444static 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
533static struct timespec s3c_rtc_delta;
534
535static int ticnt_save;
536
537static 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
558static 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
578static 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
589static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n";
590
591static int __init s3c_rtc_init(void)
592{
593 printk(banner);
594 return platform_driver_register(&s3c2410_rtcdrv);
595}
596
597static void __exit s3c_rtc_exit(void)
598{
599 platform_driver_unregister(&s3c2410_rtcdrv);
600}
601
602module_init(s3c_rtc_init);
603module_exit(s3c_rtc_exit);
604
605MODULE_DESCRIPTION("Samsung S3C RTC Driver");
606MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
607MODULE_LICENSE("GPL");
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-21 01:54:55 -0500