Loading...
1/* drivers/rtc/rtc-s3c.c
2 *
3 * Copyright (c) 2010 Samsung Electronics Co., Ltd.
4 * http://www.samsung.com/
5 *
6 * Copyright (c) 2004,2006 Simtec Electronics
7 * Ben Dooks, <ben@simtec.co.uk>
8 * http://armlinux.simtec.co.uk/
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 *
14 * S3C2410/S3C2440/S3C24XX Internal RTC Driver
15*/
16
17#include <linux/module.h>
18#include <linux/fs.h>
19#include <linux/string.h>
20#include <linux/init.h>
21#include <linux/platform_device.h>
22#include <linux/interrupt.h>
23#include <linux/rtc.h>
24#include <linux/bcd.h>
25#include <linux/clk.h>
26#include <linux/log2.h>
27#include <linux/slab.h>
28
29#include <mach/hardware.h>
30#include <asm/uaccess.h>
31#include <asm/io.h>
32#include <asm/irq.h>
33#include <plat/regs-rtc.h>
34
35enum s3c_cpu_type {
36 TYPE_S3C2410,
37 TYPE_S3C64XX,
38};
39
40/* I have yet to find an S3C implementation with more than one
41 * of these rtc blocks in */
42
43static struct resource *s3c_rtc_mem;
44
45static struct clk *rtc_clk;
46static void __iomem *s3c_rtc_base;
47static int s3c_rtc_alarmno = NO_IRQ;
48static int s3c_rtc_tickno = NO_IRQ;
49static bool wake_en;
50static enum s3c_cpu_type s3c_rtc_cpu_type;
51
52static DEFINE_SPINLOCK(s3c_rtc_pie_lock);
53
54static void s3c_rtc_alarm_clk_enable(bool enable)
55{
56 static DEFINE_SPINLOCK(s3c_rtc_alarm_clk_lock);
57 static bool alarm_clk_enabled;
58 unsigned long irq_flags;
59
60 spin_lock_irqsave(&s3c_rtc_alarm_clk_lock, irq_flags);
61 if (enable) {
62 if (!alarm_clk_enabled) {
63 clk_enable(rtc_clk);
64 alarm_clk_enabled = true;
65 }
66 } else {
67 if (alarm_clk_enabled) {
68 clk_disable(rtc_clk);
69 alarm_clk_enabled = false;
70 }
71 }
72 spin_unlock_irqrestore(&s3c_rtc_alarm_clk_lock, irq_flags);
73}
74
75/* IRQ Handlers */
76
77static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
78{
79 struct rtc_device *rdev = id;
80
81 clk_enable(rtc_clk);
82 rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
83
84 if (s3c_rtc_cpu_type == TYPE_S3C64XX)
85 writeb(S3C2410_INTP_ALM, s3c_rtc_base + S3C2410_INTP);
86
87 clk_disable(rtc_clk);
88
89 s3c_rtc_alarm_clk_enable(false);
90
91 return IRQ_HANDLED;
92}
93
94static irqreturn_t s3c_rtc_tickirq(int irq, void *id)
95{
96 struct rtc_device *rdev = id;
97
98 clk_enable(rtc_clk);
99 rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF);
100
101 if (s3c_rtc_cpu_type == TYPE_S3C64XX)
102 writeb(S3C2410_INTP_TIC, s3c_rtc_base + S3C2410_INTP);
103
104 clk_disable(rtc_clk);
105 return IRQ_HANDLED;
106}
107
108/* Update control registers */
109static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
110{
111 unsigned int tmp;
112
113 pr_debug("%s: aie=%d\n", __func__, enabled);
114
115 clk_enable(rtc_clk);
116 tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
117
118 if (enabled)
119 tmp |= S3C2410_RTCALM_ALMEN;
120
121 writeb(tmp, s3c_rtc_base + S3C2410_RTCALM);
122 clk_disable(rtc_clk);
123
124 s3c_rtc_alarm_clk_enable(enabled);
125
126 return 0;
127}
128
129static int s3c_rtc_setfreq(struct device *dev, int freq)
130{
131 struct platform_device *pdev = to_platform_device(dev);
132 struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
133 unsigned int tmp = 0;
134
135 if (!is_power_of_2(freq))
136 return -EINVAL;
137
138 clk_enable(rtc_clk);
139 spin_lock_irq(&s3c_rtc_pie_lock);
140
141 if (s3c_rtc_cpu_type == TYPE_S3C2410) {
142 tmp = readb(s3c_rtc_base + S3C2410_TICNT);
143 tmp &= S3C2410_TICNT_ENABLE;
144 }
145
146 tmp |= (rtc_dev->max_user_freq / freq)-1;
147
148 writel(tmp, s3c_rtc_base + S3C2410_TICNT);
149 spin_unlock_irq(&s3c_rtc_pie_lock);
150 clk_disable(rtc_clk);
151
152 return 0;
153}
154
155/* Time read/write */
156
157static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
158{
159 unsigned int have_retried = 0;
160 void __iomem *base = s3c_rtc_base;
161
162 clk_enable(rtc_clk);
163 retry_get_time:
164 rtc_tm->tm_min = readb(base + S3C2410_RTCMIN);
165 rtc_tm->tm_hour = readb(base + S3C2410_RTCHOUR);
166 rtc_tm->tm_mday = readb(base + S3C2410_RTCDATE);
167 rtc_tm->tm_mon = readb(base + S3C2410_RTCMON);
168 rtc_tm->tm_year = readb(base + S3C2410_RTCYEAR);
169 rtc_tm->tm_sec = readb(base + S3C2410_RTCSEC);
170
171 /* the only way to work out wether the system was mid-update
172 * when we read it is to check the second counter, and if it
173 * is zero, then we re-try the entire read
174 */
175
176 if (rtc_tm->tm_sec == 0 && !have_retried) {
177 have_retried = 1;
178 goto retry_get_time;
179 }
180
181 rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
182 rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
183 rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
184 rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
185 rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
186 rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
187
188 rtc_tm->tm_year += 100;
189
190 pr_debug("read time %04d.%02d.%02d %02d:%02d:%02d\n",
191 1900 + rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
192 rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
193
194 rtc_tm->tm_mon -= 1;
195
196 clk_disable(rtc_clk);
197 return rtc_valid_tm(rtc_tm);
198}
199
200static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
201{
202 void __iomem *base = s3c_rtc_base;
203 int year = tm->tm_year - 100;
204
205 clk_enable(rtc_clk);
206 pr_debug("set time %04d.%02d.%02d %02d:%02d:%02d\n",
207 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
208 tm->tm_hour, tm->tm_min, tm->tm_sec);
209
210 /* we get around y2k by simply not supporting it */
211
212 if (year < 0 || year >= 100) {
213 dev_err(dev, "rtc only supports 100 years\n");
214 return -EINVAL;
215 }
216
217 writeb(bin2bcd(tm->tm_sec), base + S3C2410_RTCSEC);
218 writeb(bin2bcd(tm->tm_min), base + S3C2410_RTCMIN);
219 writeb(bin2bcd(tm->tm_hour), base + S3C2410_RTCHOUR);
220 writeb(bin2bcd(tm->tm_mday), base + S3C2410_RTCDATE);
221 writeb(bin2bcd(tm->tm_mon + 1), base + S3C2410_RTCMON);
222 writeb(bin2bcd(year), base + S3C2410_RTCYEAR);
223 clk_disable(rtc_clk);
224
225 return 0;
226}
227
228static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
229{
230 struct rtc_time *alm_tm = &alrm->time;
231 void __iomem *base = s3c_rtc_base;
232 unsigned int alm_en;
233
234 clk_enable(rtc_clk);
235 alm_tm->tm_sec = readb(base + S3C2410_ALMSEC);
236 alm_tm->tm_min = readb(base + S3C2410_ALMMIN);
237 alm_tm->tm_hour = readb(base + S3C2410_ALMHOUR);
238 alm_tm->tm_mon = readb(base + S3C2410_ALMMON);
239 alm_tm->tm_mday = readb(base + S3C2410_ALMDATE);
240 alm_tm->tm_year = readb(base + S3C2410_ALMYEAR);
241
242 alm_en = readb(base + S3C2410_RTCALM);
243
244 alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;
245
246 pr_debug("read alarm %d, %04d.%02d.%02d %02d:%02d:%02d\n",
247 alm_en,
248 1900 + alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
249 alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
250
251
252 /* decode the alarm enable field */
253
254 if (alm_en & S3C2410_RTCALM_SECEN)
255 alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
256 else
257 alm_tm->tm_sec = -1;
258
259 if (alm_en & S3C2410_RTCALM_MINEN)
260 alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
261 else
262 alm_tm->tm_min = -1;
263
264 if (alm_en & S3C2410_RTCALM_HOUREN)
265 alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
266 else
267 alm_tm->tm_hour = -1;
268
269 if (alm_en & S3C2410_RTCALM_DAYEN)
270 alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);
271 else
272 alm_tm->tm_mday = -1;
273
274 if (alm_en & S3C2410_RTCALM_MONEN) {
275 alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon);
276 alm_tm->tm_mon -= 1;
277 } else {
278 alm_tm->tm_mon = -1;
279 }
280
281 if (alm_en & S3C2410_RTCALM_YEAREN)
282 alm_tm->tm_year = bcd2bin(alm_tm->tm_year);
283 else
284 alm_tm->tm_year = -1;
285
286 clk_disable(rtc_clk);
287 return 0;
288}
289
290static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
291{
292 struct rtc_time *tm = &alrm->time;
293 void __iomem *base = s3c_rtc_base;
294 unsigned int alrm_en;
295
296 clk_enable(rtc_clk);
297 pr_debug("s3c_rtc_setalarm: %d, %04d.%02d.%02d %02d:%02d:%02d\n",
298 alrm->enabled,
299 1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
300 tm->tm_hour, tm->tm_min, tm->tm_sec);
301
302 alrm_en = readb(base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
303 writeb(0x00, base + S3C2410_RTCALM);
304
305 if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
306 alrm_en |= S3C2410_RTCALM_SECEN;
307 writeb(bin2bcd(tm->tm_sec), base + S3C2410_ALMSEC);
308 }
309
310 if (tm->tm_min < 60 && tm->tm_min >= 0) {
311 alrm_en |= S3C2410_RTCALM_MINEN;
312 writeb(bin2bcd(tm->tm_min), base + S3C2410_ALMMIN);
313 }
314
315 if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
316 alrm_en |= S3C2410_RTCALM_HOUREN;
317 writeb(bin2bcd(tm->tm_hour), base + S3C2410_ALMHOUR);
318 }
319
320 pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
321
322 writeb(alrm_en, base + S3C2410_RTCALM);
323
324 s3c_rtc_setaie(dev, alrm->enabled);
325
326 clk_disable(rtc_clk);
327 return 0;
328}
329
330static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
331{
332 unsigned int ticnt;
333
334 clk_enable(rtc_clk);
335 if (s3c_rtc_cpu_type == TYPE_S3C64XX) {
336 ticnt = readw(s3c_rtc_base + S3C2410_RTCCON);
337 ticnt &= S3C64XX_RTCCON_TICEN;
338 } else {
339 ticnt = readb(s3c_rtc_base + S3C2410_TICNT);
340 ticnt &= S3C2410_TICNT_ENABLE;
341 }
342
343 seq_printf(seq, "periodic_IRQ\t: %s\n", ticnt ? "yes" : "no");
344 clk_disable(rtc_clk);
345 return 0;
346}
347
348static const struct rtc_class_ops s3c_rtcops = {
349 .read_time = s3c_rtc_gettime,
350 .set_time = s3c_rtc_settime,
351 .read_alarm = s3c_rtc_getalarm,
352 .set_alarm = s3c_rtc_setalarm,
353 .proc = s3c_rtc_proc,
354 .alarm_irq_enable = s3c_rtc_setaie,
355};
356
357static void s3c_rtc_enable(struct platform_device *pdev, int en)
358{
359 void __iomem *base = s3c_rtc_base;
360 unsigned int tmp;
361
362 if (s3c_rtc_base == NULL)
363 return;
364
365 clk_enable(rtc_clk);
366 if (!en) {
367 tmp = readw(base + S3C2410_RTCCON);
368 if (s3c_rtc_cpu_type == TYPE_S3C64XX)
369 tmp &= ~S3C64XX_RTCCON_TICEN;
370 tmp &= ~S3C2410_RTCCON_RTCEN;
371 writew(tmp, base + S3C2410_RTCCON);
372
373 if (s3c_rtc_cpu_type == TYPE_S3C2410) {
374 tmp = readb(base + S3C2410_TICNT);
375 tmp &= ~S3C2410_TICNT_ENABLE;
376 writeb(tmp, base + S3C2410_TICNT);
377 }
378 } else {
379 /* re-enable the device, and check it is ok */
380
381 if ((readw(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0) {
382 dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
383
384 tmp = readw(base + S3C2410_RTCCON);
385 writew(tmp | S3C2410_RTCCON_RTCEN,
386 base + S3C2410_RTCCON);
387 }
388
389 if ((readw(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)) {
390 dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n");
391
392 tmp = readw(base + S3C2410_RTCCON);
393 writew(tmp & ~S3C2410_RTCCON_CNTSEL,
394 base + S3C2410_RTCCON);
395 }
396
397 if ((readw(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)) {
398 dev_info(&pdev->dev, "removing RTCCON_CLKRST\n");
399
400 tmp = readw(base + S3C2410_RTCCON);
401 writew(tmp & ~S3C2410_RTCCON_CLKRST,
402 base + S3C2410_RTCCON);
403 }
404 }
405 clk_disable(rtc_clk);
406}
407
408static int __devexit s3c_rtc_remove(struct platform_device *dev)
409{
410 struct rtc_device *rtc = platform_get_drvdata(dev);
411
412 free_irq(s3c_rtc_alarmno, rtc);
413 free_irq(s3c_rtc_tickno, rtc);
414
415 platform_set_drvdata(dev, NULL);
416 rtc_device_unregister(rtc);
417
418 s3c_rtc_setaie(&dev->dev, 0);
419
420 clk_put(rtc_clk);
421 rtc_clk = NULL;
422
423 iounmap(s3c_rtc_base);
424 release_resource(s3c_rtc_mem);
425 kfree(s3c_rtc_mem);
426
427 return 0;
428}
429
430static int __devinit s3c_rtc_probe(struct platform_device *pdev)
431{
432 struct rtc_device *rtc;
433 struct rtc_time rtc_tm;
434 struct resource *res;
435 int ret;
436
437 pr_debug("%s: probe=%p\n", __func__, pdev);
438
439 /* find the IRQs */
440
441 s3c_rtc_tickno = platform_get_irq(pdev, 1);
442 if (s3c_rtc_tickno < 0) {
443 dev_err(&pdev->dev, "no irq for rtc tick\n");
444 return -ENOENT;
445 }
446
447 s3c_rtc_alarmno = platform_get_irq(pdev, 0);
448 if (s3c_rtc_alarmno < 0) {
449 dev_err(&pdev->dev, "no irq for alarm\n");
450 return -ENOENT;
451 }
452
453 pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
454 s3c_rtc_tickno, s3c_rtc_alarmno);
455
456 /* get the memory region */
457
458 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
459 if (res == NULL) {
460 dev_err(&pdev->dev, "failed to get memory region resource\n");
461 return -ENOENT;
462 }
463
464 s3c_rtc_mem = request_mem_region(res->start, resource_size(res),
465 pdev->name);
466
467 if (s3c_rtc_mem == NULL) {
468 dev_err(&pdev->dev, "failed to reserve memory region\n");
469 ret = -ENOENT;
470 goto err_nores;
471 }
472
473 s3c_rtc_base = ioremap(res->start, resource_size(res));
474 if (s3c_rtc_base == NULL) {
475 dev_err(&pdev->dev, "failed ioremap()\n");
476 ret = -EINVAL;
477 goto err_nomap;
478 }
479
480 rtc_clk = clk_get(&pdev->dev, "rtc");
481 if (IS_ERR(rtc_clk)) {
482 dev_err(&pdev->dev, "failed to find rtc clock source\n");
483 ret = PTR_ERR(rtc_clk);
484 rtc_clk = NULL;
485 goto err_clk;
486 }
487
488 clk_enable(rtc_clk);
489
490 /* check to see if everything is setup correctly */
491
492 s3c_rtc_enable(pdev, 1);
493
494 pr_debug("s3c2410_rtc: RTCCON=%02x\n",
495 readw(s3c_rtc_base + S3C2410_RTCCON));
496
497 device_init_wakeup(&pdev->dev, 1);
498
499 /* register RTC and exit */
500
501 rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops,
502 THIS_MODULE);
503
504 if (IS_ERR(rtc)) {
505 dev_err(&pdev->dev, "cannot attach rtc\n");
506 ret = PTR_ERR(rtc);
507 goto err_nortc;
508 }
509
510 s3c_rtc_cpu_type = platform_get_device_id(pdev)->driver_data;
511
512 /* Check RTC Time */
513
514 s3c_rtc_gettime(NULL, &rtc_tm);
515
516 if (rtc_valid_tm(&rtc_tm)) {
517 rtc_tm.tm_year = 100;
518 rtc_tm.tm_mon = 0;
519 rtc_tm.tm_mday = 1;
520 rtc_tm.tm_hour = 0;
521 rtc_tm.tm_min = 0;
522 rtc_tm.tm_sec = 0;
523
524 s3c_rtc_settime(NULL, &rtc_tm);
525
526 dev_warn(&pdev->dev, "warning: invalid RTC value so initializing it\n");
527 }
528
529 if (s3c_rtc_cpu_type == TYPE_S3C64XX)
530 rtc->max_user_freq = 32768;
531 else
532 rtc->max_user_freq = 128;
533
534 platform_set_drvdata(pdev, rtc);
535
536 s3c_rtc_setfreq(&pdev->dev, 1);
537
538 ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq,
539 IRQF_DISABLED, "s3c2410-rtc alarm", rtc);
540 if (ret) {
541 dev_err(&pdev->dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret);
542 goto err_alarm_irq;
543 }
544
545 ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq,
546 IRQF_DISABLED, "s3c2410-rtc tick", rtc);
547 if (ret) {
548 dev_err(&pdev->dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret);
549 free_irq(s3c_rtc_alarmno, rtc);
550 goto err_tick_irq;
551 }
552
553 clk_disable(rtc_clk);
554
555 return 0;
556
557 err_tick_irq:
558 free_irq(s3c_rtc_alarmno, rtc);
559
560 err_alarm_irq:
561 platform_set_drvdata(pdev, NULL);
562 rtc_device_unregister(rtc);
563
564 err_nortc:
565 s3c_rtc_enable(pdev, 0);
566 clk_disable(rtc_clk);
567 clk_put(rtc_clk);
568
569 err_clk:
570 iounmap(s3c_rtc_base);
571
572 err_nomap:
573 release_resource(s3c_rtc_mem);
574
575 err_nores:
576 return ret;
577}
578
579#ifdef CONFIG_PM
580
581/* RTC Power management control */
582
583static int ticnt_save, ticnt_en_save;
584
585static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state)
586{
587 clk_enable(rtc_clk);
588 /* save TICNT for anyone using periodic interrupts */
589 ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT);
590 if (s3c_rtc_cpu_type == TYPE_S3C64XX) {
591 ticnt_en_save = readw(s3c_rtc_base + S3C2410_RTCCON);
592 ticnt_en_save &= S3C64XX_RTCCON_TICEN;
593 }
594 s3c_rtc_enable(pdev, 0);
595
596 if (device_may_wakeup(&pdev->dev) && !wake_en) {
597 if (enable_irq_wake(s3c_rtc_alarmno) == 0)
598 wake_en = true;
599 else
600 dev_err(&pdev->dev, "enable_irq_wake failed\n");
601 }
602 clk_disable(rtc_clk);
603
604 return 0;
605}
606
607static int s3c_rtc_resume(struct platform_device *pdev)
608{
609 unsigned int tmp;
610
611 clk_enable(rtc_clk);
612 s3c_rtc_enable(pdev, 1);
613 writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT);
614 if (s3c_rtc_cpu_type == TYPE_S3C64XX && ticnt_en_save) {
615 tmp = readw(s3c_rtc_base + S3C2410_RTCCON);
616 writew(tmp | ticnt_en_save, s3c_rtc_base + S3C2410_RTCCON);
617 }
618
619 if (device_may_wakeup(&pdev->dev) && wake_en) {
620 disable_irq_wake(s3c_rtc_alarmno);
621 wake_en = false;
622 }
623 clk_disable(rtc_clk);
624
625 return 0;
626}
627#else
628#define s3c_rtc_suspend NULL
629#define s3c_rtc_resume NULL
630#endif
631
632static struct platform_device_id s3c_rtc_driver_ids[] = {
633 {
634 .name = "s3c2410-rtc",
635 .driver_data = TYPE_S3C2410,
636 }, {
637 .name = "s3c64xx-rtc",
638 .driver_data = TYPE_S3C64XX,
639 },
640 { }
641};
642
643MODULE_DEVICE_TABLE(platform, s3c_rtc_driver_ids);
644
645static struct platform_driver s3c_rtc_driver = {
646 .probe = s3c_rtc_probe,
647 .remove = __devexit_p(s3c_rtc_remove),
648 .suspend = s3c_rtc_suspend,
649 .resume = s3c_rtc_resume,
650 .id_table = s3c_rtc_driver_ids,
651 .driver = {
652 .name = "s3c-rtc",
653 .owner = THIS_MODULE,
654 },
655};
656
657static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n";
658
659static int __init s3c_rtc_init(void)
660{
661 printk(banner);
662 return platform_driver_register(&s3c_rtc_driver);
663}
664
665static void __exit s3c_rtc_exit(void)
666{
667 platform_driver_unregister(&s3c_rtc_driver);
668}
669
670module_init(s3c_rtc_init);
671module_exit(s3c_rtc_exit);
672
673MODULE_DESCRIPTION("Samsung S3C RTC Driver");
674MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
675MODULE_LICENSE("GPL");
676MODULE_ALIAS("platform:s3c2410-rtc");
1// SPDX-License-Identifier: GPL-2.0-only
2/* drivers/rtc/rtc-s3c.c
3 *
4 * Copyright (c) 2010 Samsung Electronics Co., Ltd.
5 * http://www.samsung.com/
6 *
7 * Copyright (c) 2004,2006 Simtec Electronics
8 * Ben Dooks, <ben@simtec.co.uk>
9 * http://armlinux.simtec.co.uk/
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#include <linux/slab.h>
25#include <linux/of.h>
26#include <linux/of_device.h>
27#include <linux/uaccess.h>
28#include <linux/io.h>
29
30#include <asm/irq.h>
31#include "rtc-s3c.h"
32
33struct s3c_rtc {
34 struct device *dev;
35 struct rtc_device *rtc;
36
37 void __iomem *base;
38 struct clk *rtc_clk;
39 struct clk *rtc_src_clk;
40 bool alarm_enabled;
41
42 const struct s3c_rtc_data *data;
43
44 int irq_alarm;
45 spinlock_t alarm_lock;
46
47 bool wake_en;
48};
49
50struct s3c_rtc_data {
51 bool needs_src_clk;
52
53 void (*irq_handler) (struct s3c_rtc *info, int mask);
54 void (*enable) (struct s3c_rtc *info);
55 void (*disable) (struct s3c_rtc *info);
56};
57
58static int s3c_rtc_enable_clk(struct s3c_rtc *info)
59{
60 int ret;
61
62 ret = clk_enable(info->rtc_clk);
63 if (ret)
64 return ret;
65
66 if (info->data->needs_src_clk) {
67 ret = clk_enable(info->rtc_src_clk);
68 if (ret) {
69 clk_disable(info->rtc_clk);
70 return ret;
71 }
72 }
73 return 0;
74}
75
76static void s3c_rtc_disable_clk(struct s3c_rtc *info)
77{
78 if (info->data->needs_src_clk)
79 clk_disable(info->rtc_src_clk);
80 clk_disable(info->rtc_clk);
81}
82
83/* IRQ Handler */
84static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
85{
86 struct s3c_rtc *info = (struct s3c_rtc *)id;
87
88 if (info->data->irq_handler)
89 info->data->irq_handler(info, S3C2410_INTP_ALM);
90
91 return IRQ_HANDLED;
92}
93
94/* Update control registers */
95static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
96{
97 struct s3c_rtc *info = dev_get_drvdata(dev);
98 unsigned long flags;
99 unsigned int tmp;
100 int ret;
101
102 dev_dbg(info->dev, "%s: aie=%d\n", __func__, enabled);
103
104 ret = s3c_rtc_enable_clk(info);
105 if (ret)
106 return ret;
107
108 tmp = readb(info->base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
109
110 if (enabled)
111 tmp |= S3C2410_RTCALM_ALMEN;
112
113 writeb(tmp, info->base + S3C2410_RTCALM);
114
115 spin_lock_irqsave(&info->alarm_lock, flags);
116
117 if (info->alarm_enabled && !enabled)
118 s3c_rtc_disable_clk(info);
119 else if (!info->alarm_enabled && enabled)
120 ret = s3c_rtc_enable_clk(info);
121
122 info->alarm_enabled = enabled;
123 spin_unlock_irqrestore(&info->alarm_lock, flags);
124
125 s3c_rtc_disable_clk(info);
126
127 return ret;
128}
129
130/* Time read/write */
131static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
132{
133 struct s3c_rtc *info = dev_get_drvdata(dev);
134 unsigned int have_retried = 0;
135 int ret;
136
137 ret = s3c_rtc_enable_clk(info);
138 if (ret)
139 return ret;
140
141retry_get_time:
142 rtc_tm->tm_min = readb(info->base + S3C2410_RTCMIN);
143 rtc_tm->tm_hour = readb(info->base + S3C2410_RTCHOUR);
144 rtc_tm->tm_mday = readb(info->base + S3C2410_RTCDATE);
145 rtc_tm->tm_mon = readb(info->base + S3C2410_RTCMON);
146 rtc_tm->tm_year = readb(info->base + S3C2410_RTCYEAR);
147 rtc_tm->tm_sec = readb(info->base + S3C2410_RTCSEC);
148
149 /* the only way to work out whether the system was mid-update
150 * when we read it is to check the second counter, and if it
151 * is zero, then we re-try the entire read
152 */
153
154 if (rtc_tm->tm_sec == 0 && !have_retried) {
155 have_retried = 1;
156 goto retry_get_time;
157 }
158
159 rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
160 rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
161 rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
162 rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
163 rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
164 rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
165
166 s3c_rtc_disable_clk(info);
167
168 rtc_tm->tm_year += 100;
169 rtc_tm->tm_mon -= 1;
170
171 dev_dbg(dev, "read time %ptR\n", rtc_tm);
172 return 0;
173}
174
175static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
176{
177 struct s3c_rtc *info = dev_get_drvdata(dev);
178 int year = tm->tm_year - 100;
179 int ret;
180
181 dev_dbg(dev, "set time %ptR\n", tm);
182
183 /* we get around y2k by simply not supporting it */
184
185 if (year < 0 || year >= 100) {
186 dev_err(dev, "rtc only supports 100 years\n");
187 return -EINVAL;
188 }
189
190 ret = s3c_rtc_enable_clk(info);
191 if (ret)
192 return ret;
193
194 writeb(bin2bcd(tm->tm_sec), info->base + S3C2410_RTCSEC);
195 writeb(bin2bcd(tm->tm_min), info->base + S3C2410_RTCMIN);
196 writeb(bin2bcd(tm->tm_hour), info->base + S3C2410_RTCHOUR);
197 writeb(bin2bcd(tm->tm_mday), info->base + S3C2410_RTCDATE);
198 writeb(bin2bcd(tm->tm_mon + 1), info->base + S3C2410_RTCMON);
199 writeb(bin2bcd(year), info->base + S3C2410_RTCYEAR);
200
201 s3c_rtc_disable_clk(info);
202
203 return 0;
204}
205
206static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
207{
208 struct s3c_rtc *info = dev_get_drvdata(dev);
209 struct rtc_time *alm_tm = &alrm->time;
210 unsigned int alm_en;
211 int ret;
212
213 ret = s3c_rtc_enable_clk(info);
214 if (ret)
215 return ret;
216
217 alm_tm->tm_sec = readb(info->base + S3C2410_ALMSEC);
218 alm_tm->tm_min = readb(info->base + S3C2410_ALMMIN);
219 alm_tm->tm_hour = readb(info->base + S3C2410_ALMHOUR);
220 alm_tm->tm_mon = readb(info->base + S3C2410_ALMMON);
221 alm_tm->tm_mday = readb(info->base + S3C2410_ALMDATE);
222 alm_tm->tm_year = readb(info->base + S3C2410_ALMYEAR);
223
224 alm_en = readb(info->base + S3C2410_RTCALM);
225
226 s3c_rtc_disable_clk(info);
227
228 alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;
229
230 dev_dbg(dev, "read alarm %d, %ptR\n", alm_en, alm_tm);
231
232 /* decode the alarm enable field */
233 if (alm_en & S3C2410_RTCALM_SECEN)
234 alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
235
236 if (alm_en & S3C2410_RTCALM_MINEN)
237 alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
238
239 if (alm_en & S3C2410_RTCALM_HOUREN)
240 alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
241
242 if (alm_en & S3C2410_RTCALM_DAYEN)
243 alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);
244
245 if (alm_en & S3C2410_RTCALM_MONEN) {
246 alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon);
247 alm_tm->tm_mon -= 1;
248 }
249
250 if (alm_en & S3C2410_RTCALM_YEAREN)
251 alm_tm->tm_year = bcd2bin(alm_tm->tm_year);
252
253 return 0;
254}
255
256static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
257{
258 struct s3c_rtc *info = dev_get_drvdata(dev);
259 struct rtc_time *tm = &alrm->time;
260 unsigned int alrm_en;
261 int ret;
262
263 dev_dbg(dev, "s3c_rtc_setalarm: %d, %ptR\n", alrm->enabled, tm);
264
265 ret = s3c_rtc_enable_clk(info);
266 if (ret)
267 return ret;
268
269 alrm_en = readb(info->base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
270 writeb(0x00, info->base + S3C2410_RTCALM);
271
272 if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
273 alrm_en |= S3C2410_RTCALM_SECEN;
274 writeb(bin2bcd(tm->tm_sec), info->base + S3C2410_ALMSEC);
275 }
276
277 if (tm->tm_min < 60 && tm->tm_min >= 0) {
278 alrm_en |= S3C2410_RTCALM_MINEN;
279 writeb(bin2bcd(tm->tm_min), info->base + S3C2410_ALMMIN);
280 }
281
282 if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
283 alrm_en |= S3C2410_RTCALM_HOUREN;
284 writeb(bin2bcd(tm->tm_hour), info->base + S3C2410_ALMHOUR);
285 }
286
287 if (tm->tm_mon < 12 && tm->tm_mon >= 0) {
288 alrm_en |= S3C2410_RTCALM_MONEN;
289 writeb(bin2bcd(tm->tm_mon + 1), info->base + S3C2410_ALMMON);
290 }
291
292 if (tm->tm_mday <= 31 && tm->tm_mday >= 1) {
293 alrm_en |= S3C2410_RTCALM_DAYEN;
294 writeb(bin2bcd(tm->tm_mday), info->base + S3C2410_ALMDATE);
295 }
296
297 dev_dbg(dev, "setting S3C2410_RTCALM to %08x\n", alrm_en);
298
299 writeb(alrm_en, info->base + S3C2410_RTCALM);
300
301 s3c_rtc_setaie(dev, alrm->enabled);
302
303 s3c_rtc_disable_clk(info);
304
305 return 0;
306}
307
308static const struct rtc_class_ops s3c_rtcops = {
309 .read_time = s3c_rtc_gettime,
310 .set_time = s3c_rtc_settime,
311 .read_alarm = s3c_rtc_getalarm,
312 .set_alarm = s3c_rtc_setalarm,
313 .alarm_irq_enable = s3c_rtc_setaie,
314};
315
316static void s3c24xx_rtc_enable(struct s3c_rtc *info)
317{
318 unsigned int con, tmp;
319
320 con = readw(info->base + S3C2410_RTCCON);
321 /* re-enable the device, and check it is ok */
322 if ((con & S3C2410_RTCCON_RTCEN) == 0) {
323 dev_info(info->dev, "rtc disabled, re-enabling\n");
324
325 tmp = readw(info->base + S3C2410_RTCCON);
326 writew(tmp | S3C2410_RTCCON_RTCEN, info->base + S3C2410_RTCCON);
327 }
328
329 if (con & S3C2410_RTCCON_CNTSEL) {
330 dev_info(info->dev, "removing RTCCON_CNTSEL\n");
331
332 tmp = readw(info->base + S3C2410_RTCCON);
333 writew(tmp & ~S3C2410_RTCCON_CNTSEL,
334 info->base + S3C2410_RTCCON);
335 }
336
337 if (con & S3C2410_RTCCON_CLKRST) {
338 dev_info(info->dev, "removing RTCCON_CLKRST\n");
339
340 tmp = readw(info->base + S3C2410_RTCCON);
341 writew(tmp & ~S3C2410_RTCCON_CLKRST,
342 info->base + S3C2410_RTCCON);
343 }
344}
345
346static void s3c24xx_rtc_disable(struct s3c_rtc *info)
347{
348 unsigned int con;
349
350 con = readw(info->base + S3C2410_RTCCON);
351 con &= ~S3C2410_RTCCON_RTCEN;
352 writew(con, info->base + S3C2410_RTCCON);
353
354 con = readb(info->base + S3C2410_TICNT);
355 con &= ~S3C2410_TICNT_ENABLE;
356 writeb(con, info->base + S3C2410_TICNT);
357}
358
359static void s3c6410_rtc_disable(struct s3c_rtc *info)
360{
361 unsigned int con;
362
363 con = readw(info->base + S3C2410_RTCCON);
364 con &= ~S3C64XX_RTCCON_TICEN;
365 con &= ~S3C2410_RTCCON_RTCEN;
366 writew(con, info->base + S3C2410_RTCCON);
367}
368
369static int s3c_rtc_remove(struct platform_device *pdev)
370{
371 struct s3c_rtc *info = platform_get_drvdata(pdev);
372
373 s3c_rtc_setaie(info->dev, 0);
374
375 if (info->data->needs_src_clk)
376 clk_unprepare(info->rtc_src_clk);
377 clk_unprepare(info->rtc_clk);
378
379 return 0;
380}
381
382static int s3c_rtc_probe(struct platform_device *pdev)
383{
384 struct s3c_rtc *info = NULL;
385 int ret;
386
387 info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
388 if (!info)
389 return -ENOMEM;
390
391 info->dev = &pdev->dev;
392 info->data = of_device_get_match_data(&pdev->dev);
393 if (!info->data) {
394 dev_err(&pdev->dev, "failed getting s3c_rtc_data\n");
395 return -EINVAL;
396 }
397 spin_lock_init(&info->alarm_lock);
398
399 platform_set_drvdata(pdev, info);
400
401 info->irq_alarm = platform_get_irq(pdev, 0);
402 if (info->irq_alarm < 0)
403 return info->irq_alarm;
404
405 dev_dbg(&pdev->dev, "s3c2410_rtc: alarm irq %d\n", info->irq_alarm);
406
407 /* get the memory region */
408 info->base = devm_platform_ioremap_resource(pdev, 0);
409 if (IS_ERR(info->base))
410 return PTR_ERR(info->base);
411
412 info->rtc_clk = devm_clk_get(&pdev->dev, "rtc");
413 if (IS_ERR(info->rtc_clk)) {
414 ret = PTR_ERR(info->rtc_clk);
415 if (ret != -EPROBE_DEFER)
416 dev_err(&pdev->dev, "failed to find rtc clock\n");
417 else
418 dev_dbg(&pdev->dev, "probe deferred due to missing rtc clk\n");
419 return ret;
420 }
421 ret = clk_prepare_enable(info->rtc_clk);
422 if (ret)
423 return ret;
424
425 if (info->data->needs_src_clk) {
426 info->rtc_src_clk = devm_clk_get(&pdev->dev, "rtc_src");
427 if (IS_ERR(info->rtc_src_clk)) {
428 ret = dev_err_probe(&pdev->dev, PTR_ERR(info->rtc_src_clk),
429 "failed to find rtc source clock\n");
430 goto err_src_clk;
431 }
432 ret = clk_prepare_enable(info->rtc_src_clk);
433 if (ret)
434 goto err_src_clk;
435 }
436
437 /* disable RTC enable bits potentially set by the bootloader */
438 if (info->data->disable)
439 info->data->disable(info);
440
441 /* check to see if everything is setup correctly */
442 if (info->data->enable)
443 info->data->enable(info);
444
445 dev_dbg(&pdev->dev, "s3c2410_rtc: RTCCON=%02x\n",
446 readw(info->base + S3C2410_RTCCON));
447
448 device_init_wakeup(&pdev->dev, 1);
449
450 /* register RTC and exit */
451 info->rtc = devm_rtc_device_register(&pdev->dev, "s3c", &s3c_rtcops,
452 THIS_MODULE);
453 if (IS_ERR(info->rtc)) {
454 dev_err(&pdev->dev, "cannot attach rtc\n");
455 ret = PTR_ERR(info->rtc);
456 goto err_nortc;
457 }
458
459 ret = devm_request_irq(&pdev->dev, info->irq_alarm, s3c_rtc_alarmirq,
460 0, "s3c2410-rtc alarm", info);
461 if (ret) {
462 dev_err(&pdev->dev, "IRQ%d error %d\n", info->irq_alarm, ret);
463 goto err_nortc;
464 }
465
466 s3c_rtc_disable_clk(info);
467
468 return 0;
469
470err_nortc:
471 if (info->data->disable)
472 info->data->disable(info);
473
474 if (info->data->needs_src_clk)
475 clk_disable_unprepare(info->rtc_src_clk);
476err_src_clk:
477 clk_disable_unprepare(info->rtc_clk);
478
479 return ret;
480}
481
482#ifdef CONFIG_PM_SLEEP
483
484static int s3c_rtc_suspend(struct device *dev)
485{
486 struct s3c_rtc *info = dev_get_drvdata(dev);
487 int ret;
488
489 ret = s3c_rtc_enable_clk(info);
490 if (ret)
491 return ret;
492
493 if (info->data->disable)
494 info->data->disable(info);
495
496 if (device_may_wakeup(dev) && !info->wake_en) {
497 if (enable_irq_wake(info->irq_alarm) == 0)
498 info->wake_en = true;
499 else
500 dev_err(dev, "enable_irq_wake failed\n");
501 }
502
503 return 0;
504}
505
506static int s3c_rtc_resume(struct device *dev)
507{
508 struct s3c_rtc *info = dev_get_drvdata(dev);
509
510 if (info->data->enable)
511 info->data->enable(info);
512
513 s3c_rtc_disable_clk(info);
514
515 if (device_may_wakeup(dev) && info->wake_en) {
516 disable_irq_wake(info->irq_alarm);
517 info->wake_en = false;
518 }
519
520 return 0;
521}
522#endif
523static SIMPLE_DEV_PM_OPS(s3c_rtc_pm_ops, s3c_rtc_suspend, s3c_rtc_resume);
524
525static void s3c24xx_rtc_irq(struct s3c_rtc *info, int mask)
526{
527 rtc_update_irq(info->rtc, 1, RTC_AF | RTC_IRQF);
528}
529
530static void s3c6410_rtc_irq(struct s3c_rtc *info, int mask)
531{
532 rtc_update_irq(info->rtc, 1, RTC_AF | RTC_IRQF);
533 writeb(mask, info->base + S3C2410_INTP);
534}
535
536static struct s3c_rtc_data const s3c2410_rtc_data = {
537 .irq_handler = s3c24xx_rtc_irq,
538 .enable = s3c24xx_rtc_enable,
539 .disable = s3c24xx_rtc_disable,
540};
541
542static struct s3c_rtc_data const s3c2416_rtc_data = {
543 .irq_handler = s3c24xx_rtc_irq,
544 .enable = s3c24xx_rtc_enable,
545 .disable = s3c24xx_rtc_disable,
546};
547
548static struct s3c_rtc_data const s3c2443_rtc_data = {
549 .irq_handler = s3c24xx_rtc_irq,
550 .enable = s3c24xx_rtc_enable,
551 .disable = s3c24xx_rtc_disable,
552};
553
554static struct s3c_rtc_data const s3c6410_rtc_data = {
555 .needs_src_clk = true,
556 .irq_handler = s3c6410_rtc_irq,
557 .enable = s3c24xx_rtc_enable,
558 .disable = s3c6410_rtc_disable,
559};
560
561static const __maybe_unused struct of_device_id s3c_rtc_dt_match[] = {
562 {
563 .compatible = "samsung,s3c2410-rtc",
564 .data = &s3c2410_rtc_data,
565 }, {
566 .compatible = "samsung,s3c2416-rtc",
567 .data = &s3c2416_rtc_data,
568 }, {
569 .compatible = "samsung,s3c2443-rtc",
570 .data = &s3c2443_rtc_data,
571 }, {
572 .compatible = "samsung,s3c6410-rtc",
573 .data = &s3c6410_rtc_data,
574 }, {
575 .compatible = "samsung,exynos3250-rtc",
576 .data = &s3c6410_rtc_data,
577 },
578 { /* sentinel */ },
579};
580MODULE_DEVICE_TABLE(of, s3c_rtc_dt_match);
581
582static struct platform_driver s3c_rtc_driver = {
583 .probe = s3c_rtc_probe,
584 .remove = s3c_rtc_remove,
585 .driver = {
586 .name = "s3c-rtc",
587 .pm = &s3c_rtc_pm_ops,
588 .of_match_table = of_match_ptr(s3c_rtc_dt_match),
589 },
590};
591module_platform_driver(s3c_rtc_driver);
592
593MODULE_DESCRIPTION("Samsung S3C RTC Driver");
594MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
595MODULE_LICENSE("GPL");
596MODULE_ALIAS("platform:s3c2410-rtc");