1 /* drivers/rtc/rtc-s3c.c
3 * Copyright (c) 2004,2006 Simtec Electronics
4 * Ben Dooks, <ben@simtec.co.uk>
5 * http://armlinux.simtec.co.uk/
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.
11 * S3C2410/S3C2440/S3C24XX Internal RTC Driver
14 #include <linux/module.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>
24 #include <asm/hardware.h>
25 #include <asm/uaccess.h>
30 #include <asm/mach/time.h>
32 #include <asm/arch/regs-rtc.h>
34 /* I have yet to find an S3C implementation with more than one
35 * of these rtc blocks in */
37 static struct resource *s3c_rtc_mem;
39 static void __iomem *s3c_rtc_base;
40 static int s3c_rtc_alarmno = NO_IRQ;
41 static int s3c_rtc_tickno = NO_IRQ;
42 static int s3c_rtc_freq = 1;
44 static DEFINE_SPINLOCK(s3c_rtc_pie_lock);
45 static unsigned int tick_count;
49 static irqreturn_t s3c_rtc_alarmirq(int irq, void *id, struct pt_regs *r)
51 struct rtc_device *rdev = id;
53 rtc_update_irq(&rdev->class_dev, 1, RTC_AF | RTC_IRQF);
57 static irqreturn_t s3c_rtc_tickirq(int irq, void *id, struct pt_regs *r)
59 struct rtc_device *rdev = id;
61 rtc_update_irq(&rdev->class_dev, tick_count++, RTC_PF | RTC_IRQF);
65 /* Update control registers */
66 static void s3c_rtc_setaie(int to)
70 pr_debug("%s: aie=%d\n", __FUNCTION__, to);
72 tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
75 tmp |= S3C2410_RTCALM_ALMEN;
77 writeb(tmp, s3c_rtc_base + S3C2410_RTCALM);
80 static void s3c_rtc_setpie(int to)
84 pr_debug("%s: pie=%d\n", __FUNCTION__, to);
86 spin_lock_irq(&s3c_rtc_pie_lock);
87 tmp = readb(s3c_rtc_base + S3C2410_TICNT) & ~S3C2410_TICNT_ENABLE;
90 tmp |= S3C2410_TICNT_ENABLE;
92 writeb(tmp, s3c_rtc_base + S3C2410_TICNT);
93 spin_unlock_irq(&s3c_rtc_pie_lock);
96 static void s3c_rtc_setfreq(int freq)
100 spin_lock_irq(&s3c_rtc_pie_lock);
101 tmp = readb(s3c_rtc_base + S3C2410_TICNT) & S3C2410_TICNT_ENABLE;
105 tmp |= (128 / freq)-1;
107 writeb(tmp, s3c_rtc_base + S3C2410_TICNT);
108 spin_unlock_irq(&s3c_rtc_pie_lock);
111 /* Time read/write */
113 static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
115 unsigned int have_retried = 0;
116 void __iomem *base = s3c_rtc_base;
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);
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
131 if (rtc_tm->tm_sec == 0 && !have_retried) {
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);
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);
147 rtc_tm->tm_year += 100;
153 static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
155 void __iomem *base = s3c_rtc_base;
156 int year = tm->tm_year - 100;
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);
162 /* we get around y2k by simply not supporting it */
164 if (year < 0 || year >= 100) {
165 dev_err(dev, "rtc only supports 100 years\n");
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);
179 static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
181 struct rtc_time *alm_tm = &alrm->time;
182 void __iomem *base = s3c_rtc_base;
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);
192 alm_en = readb(base + S3C2410_RTCALM);
194 pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
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);
200 /* decode the alarm enable field */
202 if (alm_en & S3C2410_RTCALM_SECEN)
203 BCD_TO_BIN(alm_tm->tm_sec);
205 alm_tm->tm_sec = 0xff;
207 if (alm_en & S3C2410_RTCALM_MINEN)
208 BCD_TO_BIN(alm_tm->tm_min);
210 alm_tm->tm_min = 0xff;
212 if (alm_en & S3C2410_RTCALM_HOUREN)
213 BCD_TO_BIN(alm_tm->tm_hour);
215 alm_tm->tm_hour = 0xff;
217 if (alm_en & S3C2410_RTCALM_DAYEN)
218 BCD_TO_BIN(alm_tm->tm_mday);
220 alm_tm->tm_mday = 0xff;
222 if (alm_en & S3C2410_RTCALM_MONEN) {
223 BCD_TO_BIN(alm_tm->tm_mon);
226 alm_tm->tm_mon = 0xff;
229 if (alm_en & S3C2410_RTCALM_YEAREN)
230 BCD_TO_BIN(alm_tm->tm_year);
232 alm_tm->tm_year = 0xffff;
237 static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
239 struct rtc_time *tm = &alrm->time;
240 void __iomem *base = s3c_rtc_base;
241 unsigned int alrm_en;
243 pr_debug("s3c_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
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);
249 alrm_en = readb(base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
250 writeb(0x00, base + S3C2410_RTCALM);
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);
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);
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);
267 pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
269 writeb(alrm_en, base + S3C2410_RTCALM);
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);
279 enable_irq_wake(s3c_rtc_alarmno);
281 disable_irq_wake(s3c_rtc_alarmno);
286 static int s3c_rtc_ioctl(struct device *dev,
287 unsigned int cmd, unsigned long arg)
289 unsigned int ret = -ENOIOCTLCMD;
294 s3c_rtc_setaie((cmd == RTC_AIE_ON) ? 1 : 0);
301 s3c_rtc_setpie((cmd == RTC_PIE_ON) ? 1 : 0);
306 ret = put_user(s3c_rtc_freq, (unsigned long __user *)arg);
310 /* check for power of 2 */
312 if ((arg & (arg-1)) != 0 || arg < 1) {
317 pr_debug("s3c2410_rtc: setting frequency %ld\n", arg);
319 s3c_rtc_setfreq(arg);
332 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
334 unsigned int rtcalm = readb(s3c_rtc_base + S3C2410_RTCALM);
335 unsigned int ticnt = readb(s3c_rtc_base + S3C2410_TICNT);
337 seq_printf(seq, "alarm_IRQ\t: %s\n",
338 (rtcalm & S3C2410_RTCALM_ALMEN) ? "yes" : "no" );
340 seq_printf(seq, "periodic_IRQ\t: %s\n",
341 (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" );
343 seq_printf(seq, "periodic_freq\t: %d\n", s3c_rtc_freq);
348 static int s3c_rtc_open(struct device *dev)
350 struct platform_device *pdev = to_platform_device(dev);
351 struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
354 ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq,
355 SA_INTERRUPT, "s3c2410-rtc alarm", rtc_dev);
358 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret);
362 ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq,
363 SA_INTERRUPT, "s3c2410-rtc tick", rtc_dev);
366 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret);
373 free_irq(s3c_rtc_alarmno, rtc_dev);
377 static void s3c_rtc_release(struct device *dev)
379 struct platform_device *pdev = to_platform_device(dev);
380 struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
382 /* do not clear AIE here, it may be needed for wake */
385 free_irq(s3c_rtc_alarmno, rtc_dev);
386 free_irq(s3c_rtc_tickno, rtc_dev);
389 static 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,
400 static void s3c_rtc_enable(struct platform_device *pdev, int en)
402 void __iomem *base = s3c_rtc_base;
405 if (s3c_rtc_base == NULL)
409 tmp = readb(base + S3C2410_RTCCON);
410 writeb(tmp & ~S3C2410_RTCCON_RTCEN, base + S3C2410_RTCCON);
412 tmp = readb(base + S3C2410_TICNT);
413 writeb(tmp & ~S3C2410_TICNT_ENABLE, base + S3C2410_TICNT);
415 /* re-enable the device, and check it is ok */
417 if ((readb(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){
418 dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
420 tmp = readb(base + S3C2410_RTCCON);
421 writeb(tmp|S3C2410_RTCCON_RTCEN, base+S3C2410_RTCCON);
424 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){
425 dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n");
427 tmp = readb(base + S3C2410_RTCCON);
428 writeb(tmp& ~S3C2410_RTCCON_CNTSEL, base+S3C2410_RTCCON);
431 if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){
432 dev_info(&pdev->dev, "removing RTCCON_CLKRST\n");
434 tmp = readb(base + S3C2410_RTCCON);
435 writeb(tmp & ~S3C2410_RTCCON_CLKRST, base+S3C2410_RTCCON);
440 static int s3c_rtc_remove(struct platform_device *dev)
442 struct rtc_device *rtc = platform_get_drvdata(dev);
444 platform_set_drvdata(dev, NULL);
445 rtc_device_unregister(rtc);
450 iounmap(s3c_rtc_base);
451 release_resource(s3c_rtc_mem);
457 static int s3c_rtc_probe(struct platform_device *pdev)
459 struct rtc_device *rtc;
460 struct resource *res;
463 pr_debug("%s: probe=%p\n", __FUNCTION__, pdev);
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");
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");
479 pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
480 s3c_rtc_tickno, s3c_rtc_alarmno);
482 /* get the memory region */
484 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
486 dev_err(&pdev->dev, "failed to get memory region resource\n");
490 s3c_rtc_mem = request_mem_region(res->start,
491 res->end-res->start+1,
494 if (s3c_rtc_mem == NULL) {
495 dev_err(&pdev->dev, "failed to reserve memory region\n");
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");
507 /* check to see if everything is setup correctly */
509 s3c_rtc_enable(pdev, 1);
511 pr_debug("s3c2410_rtc: RTCCON=%02x\n",
512 readb(s3c_rtc_base + S3C2410_RTCCON));
514 s3c_rtc_setfreq(s3c_rtc_freq);
516 /* register RTC and exit */
518 rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops,
522 dev_err(&pdev->dev, "cannot attach rtc\n");
527 rtc->max_user_freq = 128;
529 platform_set_drvdata(pdev, rtc);
533 s3c_rtc_enable(pdev, 0);
534 iounmap(s3c_rtc_base);
537 release_resource(s3c_rtc_mem);
545 /* RTC Power management control */
547 static struct timespec s3c_rtc_delta;
549 static int ticnt_save;
551 static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state)
554 struct timespec time;
558 /* save TICNT for anyone using periodic interrupts */
560 ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT);
562 /* calculate time delta for suspend */
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);
572 static int s3c_rtc_resume(struct platform_device *pdev)
575 struct timespec time;
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);
584 writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT);
588 #define s3c_rtc_suspend NULL
589 #define s3c_rtc_resume NULL
592 static 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,
598 .name = "s3c2410-rtc",
599 .owner = THIS_MODULE,
603 static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n";
605 static int __init s3c_rtc_init(void)
608 return platform_driver_register(&s3c2410_rtcdrv);
611 static void __exit s3c_rtc_exit(void)
613 platform_driver_unregister(&s3c2410_rtcdrv);
616 module_init(s3c_rtc_init);
617 module_exit(s3c_rtc_exit);
619 MODULE_DESCRIPTION("Samsung S3C RTC Driver");
620 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
621 MODULE_LICENSE("GPL");