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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/uaccess.h>
27#include <linux/io.h>
28
29#include <asm/irq.h>
30#include "rtc-s3c.h"
31
32struct s3c_rtc {
33 struct device *dev;
34 struct rtc_device *rtc;
35
36 void __iomem *base;
37 struct clk *rtc_clk;
38 struct clk *rtc_src_clk;
39 bool alarm_enabled;
40
41 const struct s3c_rtc_data *data;
42
43 int irq_alarm;
44 spinlock_t alarm_lock;
45
46 bool wake_en;
47};
48
49struct s3c_rtc_data {
50 bool needs_src_clk;
51
52 void (*irq_handler) (struct s3c_rtc *info, int mask);
53 void (*enable) (struct s3c_rtc *info);
54 void (*disable) (struct s3c_rtc *info);
55};
56
57static int s3c_rtc_enable_clk(struct s3c_rtc *info)
58{
59 int ret;
60
61 ret = clk_enable(info->rtc_clk);
62 if (ret)
63 return ret;
64
65 if (info->data->needs_src_clk) {
66 ret = clk_enable(info->rtc_src_clk);
67 if (ret) {
68 clk_disable(info->rtc_clk);
69 return ret;
70 }
71 }
72 return 0;
73}
74
75static void s3c_rtc_disable_clk(struct s3c_rtc *info)
76{
77 if (info->data->needs_src_clk)
78 clk_disable(info->rtc_src_clk);
79 clk_disable(info->rtc_clk);
80}
81
82/* IRQ Handler */
83static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
84{
85 struct s3c_rtc *info = (struct s3c_rtc *)id;
86
87 if (info->data->irq_handler)
88 info->data->irq_handler(info, S3C2410_INTP_ALM);
89
90 return IRQ_HANDLED;
91}
92
93/* Update control registers */
94static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
95{
96 struct s3c_rtc *info = dev_get_drvdata(dev);
97 unsigned long flags;
98 unsigned int tmp;
99 int ret;
100
101 dev_dbg(info->dev, "%s: aie=%d\n", __func__, enabled);
102
103 ret = s3c_rtc_enable_clk(info);
104 if (ret)
105 return ret;
106
107 tmp = readb(info->base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
108
109 if (enabled)
110 tmp |= S3C2410_RTCALM_ALMEN;
111
112 writeb(tmp, info->base + S3C2410_RTCALM);
113
114 spin_lock_irqsave(&info->alarm_lock, flags);
115
116 if (info->alarm_enabled && !enabled)
117 s3c_rtc_disable_clk(info);
118 else if (!info->alarm_enabled && enabled)
119 ret = s3c_rtc_enable_clk(info);
120
121 info->alarm_enabled = enabled;
122 spin_unlock_irqrestore(&info->alarm_lock, flags);
123
124 s3c_rtc_disable_clk(info);
125
126 return ret;
127}
128
129/* Read time from RTC and convert it from BCD */
130static int s3c_rtc_read_time(struct s3c_rtc *info, struct rtc_time *tm)
131{
132 unsigned int have_retried = 0;
133 int ret;
134
135 ret = s3c_rtc_enable_clk(info);
136 if (ret)
137 return ret;
138
139retry_get_time:
140 tm->tm_min = readb(info->base + S3C2410_RTCMIN);
141 tm->tm_hour = readb(info->base + S3C2410_RTCHOUR);
142 tm->tm_mday = readb(info->base + S3C2410_RTCDATE);
143 tm->tm_mon = readb(info->base + S3C2410_RTCMON);
144 tm->tm_year = readb(info->base + S3C2410_RTCYEAR);
145 tm->tm_sec = readb(info->base + S3C2410_RTCSEC);
146
147 /*
148 * The only way to work out whether the system was mid-update
149 * when we read it is to check the second counter, and if it
150 * is zero, then we re-try the entire read
151 */
152 if (tm->tm_sec == 0 && !have_retried) {
153 have_retried = 1;
154 goto retry_get_time;
155 }
156
157 s3c_rtc_disable_clk(info);
158
159 tm->tm_sec = bcd2bin(tm->tm_sec);
160 tm->tm_min = bcd2bin(tm->tm_min);
161 tm->tm_hour = bcd2bin(tm->tm_hour);
162 tm->tm_mday = bcd2bin(tm->tm_mday);
163 tm->tm_mon = bcd2bin(tm->tm_mon);
164 tm->tm_year = bcd2bin(tm->tm_year);
165
166 return 0;
167}
168
169/* Convert time to BCD and write it to RTC */
170static int s3c_rtc_write_time(struct s3c_rtc *info, const struct rtc_time *tm)
171{
172 int ret;
173
174 ret = s3c_rtc_enable_clk(info);
175 if (ret)
176 return ret;
177
178 writeb(bin2bcd(tm->tm_sec), info->base + S3C2410_RTCSEC);
179 writeb(bin2bcd(tm->tm_min), info->base + S3C2410_RTCMIN);
180 writeb(bin2bcd(tm->tm_hour), info->base + S3C2410_RTCHOUR);
181 writeb(bin2bcd(tm->tm_mday), info->base + S3C2410_RTCDATE);
182 writeb(bin2bcd(tm->tm_mon), info->base + S3C2410_RTCMON);
183 writeb(bin2bcd(tm->tm_year), info->base + S3C2410_RTCYEAR);
184
185 s3c_rtc_disable_clk(info);
186
187 return 0;
188}
189
190static int s3c_rtc_gettime(struct device *dev, struct rtc_time *tm)
191{
192 struct s3c_rtc *info = dev_get_drvdata(dev);
193 int ret;
194
195 ret = s3c_rtc_read_time(info, tm);
196 if (ret)
197 return ret;
198
199 /* Convert internal representation to actual date/time */
200 tm->tm_year += 100;
201 tm->tm_mon -= 1;
202
203 dev_dbg(dev, "read time %ptR\n", tm);
204 return 0;
205}
206
207static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
208{
209 struct s3c_rtc *info = dev_get_drvdata(dev);
210 struct rtc_time rtc_tm = *tm;
211
212 dev_dbg(dev, "set time %ptR\n", tm);
213
214 /*
215 * Convert actual date/time to internal representation.
216 * We get around Y2K by simply not supporting it.
217 */
218 rtc_tm.tm_year -= 100;
219 rtc_tm.tm_mon += 1;
220
221 return s3c_rtc_write_time(info, &rtc_tm);
222}
223
224static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
225{
226 struct s3c_rtc *info = dev_get_drvdata(dev);
227 struct rtc_time *alm_tm = &alrm->time;
228 unsigned int alm_en;
229 int ret;
230
231 ret = s3c_rtc_enable_clk(info);
232 if (ret)
233 return ret;
234
235 alm_tm->tm_sec = readb(info->base + S3C2410_ALMSEC);
236 alm_tm->tm_min = readb(info->base + S3C2410_ALMMIN);
237 alm_tm->tm_hour = readb(info->base + S3C2410_ALMHOUR);
238 alm_tm->tm_mon = readb(info->base + S3C2410_ALMMON);
239 alm_tm->tm_mday = readb(info->base + S3C2410_ALMDATE);
240 alm_tm->tm_year = readb(info->base + S3C2410_ALMYEAR);
241
242 alm_en = readb(info->base + S3C2410_RTCALM);
243
244 s3c_rtc_disable_clk(info);
245
246 alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;
247
248 dev_dbg(dev, "read alarm %d, %ptR\n", alm_en, alm_tm);
249
250 /* decode the alarm enable field */
251 if (alm_en & S3C2410_RTCALM_SECEN)
252 alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
253
254 if (alm_en & S3C2410_RTCALM_MINEN)
255 alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
256
257 if (alm_en & S3C2410_RTCALM_HOUREN)
258 alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
259
260 if (alm_en & S3C2410_RTCALM_DAYEN)
261 alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);
262
263 if (alm_en & S3C2410_RTCALM_MONEN) {
264 alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon);
265 alm_tm->tm_mon -= 1;
266 }
267
268 if (alm_en & S3C2410_RTCALM_YEAREN)
269 alm_tm->tm_year = bcd2bin(alm_tm->tm_year);
270
271 return 0;
272}
273
274static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
275{
276 struct s3c_rtc *info = dev_get_drvdata(dev);
277 struct rtc_time *tm = &alrm->time;
278 unsigned int alrm_en;
279 int ret;
280
281 dev_dbg(dev, "s3c_rtc_setalarm: %d, %ptR\n", alrm->enabled, tm);
282
283 ret = s3c_rtc_enable_clk(info);
284 if (ret)
285 return ret;
286
287 alrm_en = readb(info->base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
288 writeb(0x00, info->base + S3C2410_RTCALM);
289
290 if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
291 alrm_en |= S3C2410_RTCALM_SECEN;
292 writeb(bin2bcd(tm->tm_sec), info->base + S3C2410_ALMSEC);
293 }
294
295 if (tm->tm_min < 60 && tm->tm_min >= 0) {
296 alrm_en |= S3C2410_RTCALM_MINEN;
297 writeb(bin2bcd(tm->tm_min), info->base + S3C2410_ALMMIN);
298 }
299
300 if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
301 alrm_en |= S3C2410_RTCALM_HOUREN;
302 writeb(bin2bcd(tm->tm_hour), info->base + S3C2410_ALMHOUR);
303 }
304
305 if (tm->tm_mon < 12 && tm->tm_mon >= 0) {
306 alrm_en |= S3C2410_RTCALM_MONEN;
307 writeb(bin2bcd(tm->tm_mon + 1), info->base + S3C2410_ALMMON);
308 }
309
310 if (tm->tm_mday <= 31 && tm->tm_mday >= 1) {
311 alrm_en |= S3C2410_RTCALM_DAYEN;
312 writeb(bin2bcd(tm->tm_mday), info->base + S3C2410_ALMDATE);
313 }
314
315 dev_dbg(dev, "setting S3C2410_RTCALM to %08x\n", alrm_en);
316
317 writeb(alrm_en, info->base + S3C2410_RTCALM);
318
319 s3c_rtc_setaie(dev, alrm->enabled);
320
321 s3c_rtc_disable_clk(info);
322
323 return 0;
324}
325
326static const struct rtc_class_ops s3c_rtcops = {
327 .read_time = s3c_rtc_gettime,
328 .set_time = s3c_rtc_settime,
329 .read_alarm = s3c_rtc_getalarm,
330 .set_alarm = s3c_rtc_setalarm,
331 .alarm_irq_enable = s3c_rtc_setaie,
332};
333
334static void s3c24xx_rtc_enable(struct s3c_rtc *info)
335{
336 unsigned int con, tmp;
337
338 con = readw(info->base + S3C2410_RTCCON);
339 /* re-enable the device, and check it is ok */
340 if ((con & S3C2410_RTCCON_RTCEN) == 0) {
341 dev_info(info->dev, "rtc disabled, re-enabling\n");
342
343 tmp = readw(info->base + S3C2410_RTCCON);
344 writew(tmp | S3C2410_RTCCON_RTCEN, info->base + S3C2410_RTCCON);
345 }
346
347 if (con & S3C2410_RTCCON_CNTSEL) {
348 dev_info(info->dev, "removing RTCCON_CNTSEL\n");
349
350 tmp = readw(info->base + S3C2410_RTCCON);
351 writew(tmp & ~S3C2410_RTCCON_CNTSEL,
352 info->base + S3C2410_RTCCON);
353 }
354
355 if (con & S3C2410_RTCCON_CLKRST) {
356 dev_info(info->dev, "removing RTCCON_CLKRST\n");
357
358 tmp = readw(info->base + S3C2410_RTCCON);
359 writew(tmp & ~S3C2410_RTCCON_CLKRST,
360 info->base + S3C2410_RTCCON);
361 }
362}
363
364static void s3c24xx_rtc_disable(struct s3c_rtc *info)
365{
366 unsigned int con;
367
368 con = readw(info->base + S3C2410_RTCCON);
369 con &= ~S3C2410_RTCCON_RTCEN;
370 writew(con, info->base + S3C2410_RTCCON);
371
372 con = readb(info->base + S3C2410_TICNT);
373 con &= ~S3C2410_TICNT_ENABLE;
374 writeb(con, info->base + S3C2410_TICNT);
375}
376
377static void s3c6410_rtc_disable(struct s3c_rtc *info)
378{
379 unsigned int con;
380
381 con = readw(info->base + S3C2410_RTCCON);
382 con &= ~S3C64XX_RTCCON_TICEN;
383 con &= ~S3C2410_RTCCON_RTCEN;
384 writew(con, info->base + S3C2410_RTCCON);
385}
386
387static void s3c_rtc_remove(struct platform_device *pdev)
388{
389 struct s3c_rtc *info = platform_get_drvdata(pdev);
390
391 s3c_rtc_setaie(info->dev, 0);
392
393 if (info->data->needs_src_clk)
394 clk_unprepare(info->rtc_src_clk);
395 clk_unprepare(info->rtc_clk);
396}
397
398static int s3c_rtc_probe(struct platform_device *pdev)
399{
400 struct s3c_rtc *info = NULL;
401 int ret;
402
403 info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
404 if (!info)
405 return -ENOMEM;
406
407 info->dev = &pdev->dev;
408 info->data = of_device_get_match_data(&pdev->dev);
409 if (!info->data) {
410 dev_err(&pdev->dev, "failed getting s3c_rtc_data\n");
411 return -EINVAL;
412 }
413 spin_lock_init(&info->alarm_lock);
414
415 platform_set_drvdata(pdev, info);
416
417 info->irq_alarm = platform_get_irq(pdev, 0);
418 if (info->irq_alarm < 0)
419 return info->irq_alarm;
420
421 dev_dbg(&pdev->dev, "s3c2410_rtc: alarm irq %d\n", info->irq_alarm);
422
423 /* get the memory region */
424 info->base = devm_platform_ioremap_resource(pdev, 0);
425 if (IS_ERR(info->base))
426 return PTR_ERR(info->base);
427
428 info->rtc_clk = devm_clk_get(&pdev->dev, "rtc");
429 if (IS_ERR(info->rtc_clk))
430 return dev_err_probe(&pdev->dev, PTR_ERR(info->rtc_clk),
431 "failed to find rtc clock\n");
432 ret = clk_prepare_enable(info->rtc_clk);
433 if (ret)
434 return ret;
435
436 if (info->data->needs_src_clk) {
437 info->rtc_src_clk = devm_clk_get(&pdev->dev, "rtc_src");
438 if (IS_ERR(info->rtc_src_clk)) {
439 ret = dev_err_probe(&pdev->dev, PTR_ERR(info->rtc_src_clk),
440 "failed to find rtc source clock\n");
441 goto err_src_clk;
442 }
443 ret = clk_prepare_enable(info->rtc_src_clk);
444 if (ret)
445 goto err_src_clk;
446 }
447
448 /* disable RTC enable bits potentially set by the bootloader */
449 if (info->data->disable)
450 info->data->disable(info);
451
452 /* check to see if everything is setup correctly */
453 if (info->data->enable)
454 info->data->enable(info);
455
456 dev_dbg(&pdev->dev, "s3c2410_rtc: RTCCON=%02x\n",
457 readw(info->base + S3C2410_RTCCON));
458
459 device_init_wakeup(&pdev->dev, 1);
460
461 info->rtc = devm_rtc_allocate_device(&pdev->dev);
462 if (IS_ERR(info->rtc)) {
463 ret = PTR_ERR(info->rtc);
464 goto err_nortc;
465 }
466
467 info->rtc->ops = &s3c_rtcops;
468 info->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
469 info->rtc->range_max = RTC_TIMESTAMP_END_2099;
470
471 ret = devm_rtc_register_device(info->rtc);
472 if (ret)
473 goto err_nortc;
474
475 ret = devm_request_irq(&pdev->dev, info->irq_alarm, s3c_rtc_alarmirq,
476 0, "s3c2410-rtc alarm", info);
477 if (ret) {
478 dev_err(&pdev->dev, "IRQ%d error %d\n", info->irq_alarm, ret);
479 goto err_nortc;
480 }
481
482 s3c_rtc_disable_clk(info);
483
484 return 0;
485
486err_nortc:
487 if (info->data->disable)
488 info->data->disable(info);
489
490 if (info->data->needs_src_clk)
491 clk_disable_unprepare(info->rtc_src_clk);
492err_src_clk:
493 clk_disable_unprepare(info->rtc_clk);
494
495 return ret;
496}
497
498#ifdef CONFIG_PM_SLEEP
499
500static int s3c_rtc_suspend(struct device *dev)
501{
502 struct s3c_rtc *info = dev_get_drvdata(dev);
503 int ret;
504
505 ret = s3c_rtc_enable_clk(info);
506 if (ret)
507 return ret;
508
509 if (info->data->disable)
510 info->data->disable(info);
511
512 if (device_may_wakeup(dev) && !info->wake_en) {
513 if (enable_irq_wake(info->irq_alarm) == 0)
514 info->wake_en = true;
515 else
516 dev_err(dev, "enable_irq_wake failed\n");
517 }
518
519 return 0;
520}
521
522static int s3c_rtc_resume(struct device *dev)
523{
524 struct s3c_rtc *info = dev_get_drvdata(dev);
525
526 if (info->data->enable)
527 info->data->enable(info);
528
529 s3c_rtc_disable_clk(info);
530
531 if (device_may_wakeup(dev) && info->wake_en) {
532 disable_irq_wake(info->irq_alarm);
533 info->wake_en = false;
534 }
535
536 return 0;
537}
538#endif
539static SIMPLE_DEV_PM_OPS(s3c_rtc_pm_ops, s3c_rtc_suspend, s3c_rtc_resume);
540
541static void s3c24xx_rtc_irq(struct s3c_rtc *info, int mask)
542{
543 rtc_update_irq(info->rtc, 1, RTC_AF | RTC_IRQF);
544}
545
546static void s3c6410_rtc_irq(struct s3c_rtc *info, int mask)
547{
548 rtc_update_irq(info->rtc, 1, RTC_AF | RTC_IRQF);
549 writeb(mask, info->base + S3C2410_INTP);
550}
551
552static struct s3c_rtc_data const s3c2410_rtc_data = {
553 .irq_handler = s3c24xx_rtc_irq,
554 .enable = s3c24xx_rtc_enable,
555 .disable = s3c24xx_rtc_disable,
556};
557
558static struct s3c_rtc_data const s3c2416_rtc_data = {
559 .irq_handler = s3c24xx_rtc_irq,
560 .enable = s3c24xx_rtc_enable,
561 .disable = s3c24xx_rtc_disable,
562};
563
564static struct s3c_rtc_data const s3c2443_rtc_data = {
565 .irq_handler = s3c24xx_rtc_irq,
566 .enable = s3c24xx_rtc_enable,
567 .disable = s3c24xx_rtc_disable,
568};
569
570static struct s3c_rtc_data const s3c6410_rtc_data = {
571 .needs_src_clk = true,
572 .irq_handler = s3c6410_rtc_irq,
573 .enable = s3c24xx_rtc_enable,
574 .disable = s3c6410_rtc_disable,
575};
576
577static const __maybe_unused struct of_device_id s3c_rtc_dt_match[] = {
578 {
579 .compatible = "samsung,s3c2410-rtc",
580 .data = &s3c2410_rtc_data,
581 }, {
582 .compatible = "samsung,s3c2416-rtc",
583 .data = &s3c2416_rtc_data,
584 }, {
585 .compatible = "samsung,s3c2443-rtc",
586 .data = &s3c2443_rtc_data,
587 }, {
588 .compatible = "samsung,s3c6410-rtc",
589 .data = &s3c6410_rtc_data,
590 }, {
591 .compatible = "samsung,exynos3250-rtc",
592 .data = &s3c6410_rtc_data,
593 },
594 { /* sentinel */ },
595};
596MODULE_DEVICE_TABLE(of, s3c_rtc_dt_match);
597
598static struct platform_driver s3c_rtc_driver = {
599 .probe = s3c_rtc_probe,
600 .remove_new = s3c_rtc_remove,
601 .driver = {
602 .name = "s3c-rtc",
603 .pm = &s3c_rtc_pm_ops,
604 .of_match_table = of_match_ptr(s3c_rtc_dt_match),
605 },
606};
607module_platform_driver(s3c_rtc_driver);
608
609MODULE_DESCRIPTION("Samsung S3C RTC Driver");
610MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
611MODULE_LICENSE("GPL");
612MODULE_ALIAS("platform:s3c2410-rtc");