1 /* drivers/rtc/rtc-s3c.c
3 * Copyright (c) 2010 Samsung Electronics Co., Ltd.
4 * http://www.samsung.com/
6 * Copyright (c) 2004,2006 Simtec Electronics
7 * Ben Dooks, <ben@simtec.co.uk>
8 * http://armlinux.simtec.co.uk/
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.
14 * S3C2410/S3C2440/S3C24XX Internal RTC Driver
17 #include <linux/module.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>
29 #include <mach/hardware.h>
30 #include <asm/uaccess.h>
33 #include <plat/regs-rtc.h>
40 /* I have yet to find an S3C implementation with more than one
41 * of these rtc blocks in */
43 static struct resource *s3c_rtc_mem;
45 static struct clk *rtc_clk;
46 static void __iomem *s3c_rtc_base;
47 static int s3c_rtc_alarmno = NO_IRQ;
48 static int s3c_rtc_tickno = NO_IRQ;
50 static enum s3c_cpu_type s3c_rtc_cpu_type;
52 static DEFINE_SPINLOCK(s3c_rtc_pie_lock);
54 static void s3c_rtc_alarm_clk_enable(bool enable)
56 static DEFINE_SPINLOCK(s3c_rtc_alarm_clk_lock);
57 static bool alarm_clk_enabled;
58 unsigned long irq_flags;
60 spin_lock_irqsave(&s3c_rtc_alarm_clk_lock, irq_flags);
62 if (!alarm_clk_enabled) {
64 alarm_clk_enabled = true;
67 if (alarm_clk_enabled) {
69 alarm_clk_enabled = false;
72 spin_unlock_irqrestore(&s3c_rtc_alarm_clk_lock, irq_flags);
77 static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
79 struct rtc_device *rdev = id;
82 rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
84 if (s3c_rtc_cpu_type == TYPE_S3C64XX)
85 writeb(S3C2410_INTP_ALM, s3c_rtc_base + S3C2410_INTP);
89 s3c_rtc_alarm_clk_enable(false);
94 static irqreturn_t s3c_rtc_tickirq(int irq, void *id)
96 struct rtc_device *rdev = id;
99 rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF);
101 if (s3c_rtc_cpu_type == TYPE_S3C64XX)
102 writeb(S3C2410_INTP_TIC, s3c_rtc_base + S3C2410_INTP);
104 clk_disable(rtc_clk);
108 /* Update control registers */
109 static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
113 pr_debug("%s: aie=%d\n", __func__, enabled);
116 tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
119 tmp |= S3C2410_RTCALM_ALMEN;
121 writeb(tmp, s3c_rtc_base + S3C2410_RTCALM);
122 clk_disable(rtc_clk);
124 s3c_rtc_alarm_clk_enable(enabled);
129 static int s3c_rtc_setfreq(struct device *dev, int freq)
131 struct platform_device *pdev = to_platform_device(dev);
132 struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
133 unsigned int tmp = 0;
135 if (!is_power_of_2(freq))
139 spin_lock_irq(&s3c_rtc_pie_lock);
141 if (s3c_rtc_cpu_type == TYPE_S3C2410) {
142 tmp = readb(s3c_rtc_base + S3C2410_TICNT);
143 tmp &= S3C2410_TICNT_ENABLE;
146 tmp |= (rtc_dev->max_user_freq / freq)-1;
148 writel(tmp, s3c_rtc_base + S3C2410_TICNT);
149 spin_unlock_irq(&s3c_rtc_pie_lock);
150 clk_disable(rtc_clk);
155 /* Time read/write */
157 static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
159 unsigned int have_retried = 0;
160 void __iomem *base = s3c_rtc_base;
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);
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
176 if (rtc_tm->tm_sec == 0 && !have_retried) {
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);
188 rtc_tm->tm_year += 100;
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);
196 clk_disable(rtc_clk);
197 return rtc_valid_tm(rtc_tm);
200 static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
202 void __iomem *base = s3c_rtc_base;
203 int year = tm->tm_year - 100;
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);
210 /* we get around y2k by simply not supporting it */
212 if (year < 0 || year >= 100) {
213 dev_err(dev, "rtc only supports 100 years\n");
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);
228 static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
230 struct rtc_time *alm_tm = &alrm->time;
231 void __iomem *base = s3c_rtc_base;
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);
242 alm_en = readb(base + S3C2410_RTCALM);
244 alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;
246 pr_debug("read alarm %d, %04d.%02d.%02d %02d:%02d:%02d\n",
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);
252 /* decode the alarm enable field */
254 if (alm_en & S3C2410_RTCALM_SECEN)
255 alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
259 if (alm_en & S3C2410_RTCALM_MINEN)
260 alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
264 if (alm_en & S3C2410_RTCALM_HOUREN)
265 alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
267 alm_tm->tm_hour = -1;
269 if (alm_en & S3C2410_RTCALM_DAYEN)
270 alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);
272 alm_tm->tm_mday = -1;
274 if (alm_en & S3C2410_RTCALM_MONEN) {
275 alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon);
281 if (alm_en & S3C2410_RTCALM_YEAREN)
282 alm_tm->tm_year = bcd2bin(alm_tm->tm_year);
284 alm_tm->tm_year = -1;
286 clk_disable(rtc_clk);
290 static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
292 struct rtc_time *tm = &alrm->time;
293 void __iomem *base = s3c_rtc_base;
294 unsigned int alrm_en;
297 pr_debug("s3c_rtc_setalarm: %d, %04d.%02d.%02d %02d:%02d:%02d\n",
299 1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
300 tm->tm_hour, tm->tm_min, tm->tm_sec);
302 alrm_en = readb(base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
303 writeb(0x00, base + S3C2410_RTCALM);
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);
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);
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);
320 pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
322 writeb(alrm_en, base + S3C2410_RTCALM);
324 s3c_rtc_setaie(dev, alrm->enabled);
326 clk_disable(rtc_clk);
330 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
335 if (s3c_rtc_cpu_type == TYPE_S3C64XX) {
336 ticnt = readw(s3c_rtc_base + S3C2410_RTCCON);
337 ticnt &= S3C64XX_RTCCON_TICEN;
339 ticnt = readb(s3c_rtc_base + S3C2410_TICNT);
340 ticnt &= S3C2410_TICNT_ENABLE;
343 seq_printf(seq, "periodic_IRQ\t: %s\n", ticnt ? "yes" : "no");
344 clk_disable(rtc_clk);
348 static 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,
357 static void s3c_rtc_enable(struct platform_device *pdev, int en)
359 void __iomem *base = s3c_rtc_base;
362 if (s3c_rtc_base == NULL)
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);
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);
379 /* re-enable the device, and check it is ok */
381 if ((readw(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0) {
382 dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
384 tmp = readw(base + S3C2410_RTCCON);
385 writew(tmp | S3C2410_RTCCON_RTCEN,
386 base + S3C2410_RTCCON);
389 if ((readw(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)) {
390 dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n");
392 tmp = readw(base + S3C2410_RTCCON);
393 writew(tmp & ~S3C2410_RTCCON_CNTSEL,
394 base + S3C2410_RTCCON);
397 if ((readw(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)) {
398 dev_info(&pdev->dev, "removing RTCCON_CLKRST\n");
400 tmp = readw(base + S3C2410_RTCCON);
401 writew(tmp & ~S3C2410_RTCCON_CLKRST,
402 base + S3C2410_RTCCON);
405 clk_disable(rtc_clk);
408 static int __devexit s3c_rtc_remove(struct platform_device *dev)
410 struct rtc_device *rtc = platform_get_drvdata(dev);
412 free_irq(s3c_rtc_alarmno, rtc);
413 free_irq(s3c_rtc_tickno, rtc);
415 platform_set_drvdata(dev, NULL);
416 rtc_device_unregister(rtc);
418 s3c_rtc_setaie(&dev->dev, 0);
423 iounmap(s3c_rtc_base);
424 release_resource(s3c_rtc_mem);
430 static int __devinit s3c_rtc_probe(struct platform_device *pdev)
432 struct rtc_device *rtc;
433 struct rtc_time rtc_tm;
434 struct resource *res;
437 pr_debug("%s: probe=%p\n", __func__, pdev);
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");
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");
453 pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
454 s3c_rtc_tickno, s3c_rtc_alarmno);
456 /* get the memory region */
458 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
460 dev_err(&pdev->dev, "failed to get memory region resource\n");
464 s3c_rtc_mem = request_mem_region(res->start, resource_size(res),
467 if (s3c_rtc_mem == NULL) {
468 dev_err(&pdev->dev, "failed to reserve memory region\n");
473 s3c_rtc_base = ioremap(res->start, resource_size(res));
474 if (s3c_rtc_base == NULL) {
475 dev_err(&pdev->dev, "failed ioremap()\n");
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);
490 /* check to see if everything is setup correctly */
492 s3c_rtc_enable(pdev, 1);
494 pr_debug("s3c2410_rtc: RTCCON=%02x\n",
495 readw(s3c_rtc_base + S3C2410_RTCCON));
497 device_init_wakeup(&pdev->dev, 1);
499 /* register RTC and exit */
501 rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops,
505 dev_err(&pdev->dev, "cannot attach rtc\n");
510 s3c_rtc_cpu_type = platform_get_device_id(pdev)->driver_data;
514 s3c_rtc_gettime(NULL, &rtc_tm);
516 if (rtc_valid_tm(&rtc_tm)) {
517 rtc_tm.tm_year = 100;
524 s3c_rtc_settime(NULL, &rtc_tm);
526 dev_warn(&pdev->dev, "warning: invalid RTC value so initializing it\n");
529 if (s3c_rtc_cpu_type == TYPE_S3C64XX)
530 rtc->max_user_freq = 32768;
532 rtc->max_user_freq = 128;
534 platform_set_drvdata(pdev, rtc);
536 s3c_rtc_setfreq(&pdev->dev, 1);
538 ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq,
539 IRQF_DISABLED, "s3c2410-rtc alarm", rtc);
541 dev_err(&pdev->dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret);
545 ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq,
546 IRQF_DISABLED, "s3c2410-rtc tick", rtc);
548 dev_err(&pdev->dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret);
549 free_irq(s3c_rtc_alarmno, rtc);
553 clk_disable(rtc_clk);
558 free_irq(s3c_rtc_alarmno, rtc);
561 platform_set_drvdata(pdev, NULL);
562 rtc_device_unregister(rtc);
565 s3c_rtc_enable(pdev, 0);
566 clk_disable(rtc_clk);
570 iounmap(s3c_rtc_base);
573 release_resource(s3c_rtc_mem);
581 /* RTC Power management control */
583 static int ticnt_save, ticnt_en_save;
585 static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state)
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;
594 s3c_rtc_enable(pdev, 0);
596 if (device_may_wakeup(&pdev->dev) && !wake_en) {
597 if (enable_irq_wake(s3c_rtc_alarmno) == 0)
600 dev_err(&pdev->dev, "enable_irq_wake failed\n");
602 clk_disable(rtc_clk);
607 static int s3c_rtc_resume(struct platform_device *pdev)
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);
619 if (device_may_wakeup(&pdev->dev) && wake_en) {
620 disable_irq_wake(s3c_rtc_alarmno);
623 clk_disable(rtc_clk);
628 #define s3c_rtc_suspend NULL
629 #define s3c_rtc_resume NULL
632 static struct platform_device_id s3c_rtc_driver_ids[] = {
634 .name = "s3c2410-rtc",
635 .driver_data = TYPE_S3C2410,
637 .name = "s3c64xx-rtc",
638 .driver_data = TYPE_S3C64XX,
643 MODULE_DEVICE_TABLE(platform, s3c_rtc_driver_ids);
645 static 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,
653 .owner = THIS_MODULE,
657 static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n";
659 static int __init s3c_rtc_init(void)
662 return platform_driver_register(&s3c_rtc_driver);
665 static void __exit s3c_rtc_exit(void)
667 platform_driver_unregister(&s3c_rtc_driver);
670 module_init(s3c_rtc_init);
671 module_exit(s3c_rtc_exit);
673 MODULE_DESCRIPTION("Samsung S3C RTC Driver");
674 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
675 MODULE_LICENSE("GPL");
676 MODULE_ALIAS("platform:s3c2410-rtc");