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path: root/drivers/rtc/rtc-s3c.c
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-rw-r--r--drivers/rtc/rtc-s3c.c621
1 files changed, 621 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c
new file mode 100644
index 00000000000..2c7de79c83b
--- /dev/null
+++ b/drivers/rtc/rtc-s3c.c
@@ -0,0 +1,621 @@
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(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
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(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
96static 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
113static 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
153static 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
179static 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
237static 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
286static 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
332static 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
348static 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
377static 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
389static 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
400static 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
440static 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
457static 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
547static struct timespec s3c_rtc_delta;
548
549static int ticnt_save;
550
551static 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
572static 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
592static 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
603static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n";
604
605static int __init s3c_rtc_init(void)
606{
607 printk(banner);
608 return platform_driver_register(&s3c2410_rtcdrv);
609}
610
611static void __exit s3c_rtc_exit(void)
612{
613 platform_driver_unregister(&s3c2410_rtcdrv);
614}
615
616module_init(s3c_rtc_init);
617module_exit(s3c_rtc_exit);
618
619MODULE_DESCRIPTION("Samsung S3C RTC Driver");
620MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
621MODULE_LICENSE("GPL");
generated by cgit v1.2.2 (git 2.25.0) at 2025-05-03 08:43:19 -0400