Merge branch 'for-linus' of git://neil.brown.name/md
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / rtc / rtc-s3c.c
blob16512ecae31a384fef42e743884b5b0c8d905d7d
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>
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>
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>
35 enum s3c_cpu_type {
36 TYPE_S3C2410,
37 TYPE_S3C64XX,
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;
49 static bool wake_en;
50 static enum s3c_cpu_type s3c_rtc_cpu_type;
52 static DEFINE_SPINLOCK(s3c_rtc_pie_lock);
54 /* IRQ Handlers */
56 static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
58 struct rtc_device *rdev = id;
60 rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
62 if (s3c_rtc_cpu_type == TYPE_S3C64XX)
63 writeb(S3C2410_INTP_ALM, s3c_rtc_base + S3C2410_INTP);
65 return IRQ_HANDLED;
68 static irqreturn_t s3c_rtc_tickirq(int irq, void *id)
70 struct rtc_device *rdev = id;
72 rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF);
74 if (s3c_rtc_cpu_type == TYPE_S3C64XX)
75 writeb(S3C2410_INTP_TIC, s3c_rtc_base + S3C2410_INTP);
77 return IRQ_HANDLED;
80 /* Update control registers */
81 static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
83 unsigned int tmp;
85 pr_debug("%s: aie=%d\n", __func__, enabled);
87 tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
89 if (enabled)
90 tmp |= S3C2410_RTCALM_ALMEN;
92 writeb(tmp, s3c_rtc_base + S3C2410_RTCALM);
94 return 0;
97 static int s3c_rtc_setfreq(struct device *dev, int freq)
99 struct platform_device *pdev = to_platform_device(dev);
100 struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
101 unsigned int tmp = 0;
103 if (!is_power_of_2(freq))
104 return -EINVAL;
106 spin_lock_irq(&s3c_rtc_pie_lock);
108 if (s3c_rtc_cpu_type == TYPE_S3C2410) {
109 tmp = readb(s3c_rtc_base + S3C2410_TICNT);
110 tmp &= S3C2410_TICNT_ENABLE;
113 tmp |= (rtc_dev->max_user_freq / freq)-1;
115 writel(tmp, s3c_rtc_base + S3C2410_TICNT);
116 spin_unlock_irq(&s3c_rtc_pie_lock);
118 return 0;
121 /* Time read/write */
123 static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
125 unsigned int have_retried = 0;
126 void __iomem *base = s3c_rtc_base;
128 retry_get_time:
129 rtc_tm->tm_min = readb(base + S3C2410_RTCMIN);
130 rtc_tm->tm_hour = readb(base + S3C2410_RTCHOUR);
131 rtc_tm->tm_mday = readb(base + S3C2410_RTCDATE);
132 rtc_tm->tm_mon = readb(base + S3C2410_RTCMON);
133 rtc_tm->tm_year = readb(base + S3C2410_RTCYEAR);
134 rtc_tm->tm_sec = readb(base + S3C2410_RTCSEC);
136 /* the only way to work out wether the system was mid-update
137 * when we read it is to check the second counter, and if it
138 * is zero, then we re-try the entire read
141 if (rtc_tm->tm_sec == 0 && !have_retried) {
142 have_retried = 1;
143 goto retry_get_time;
146 pr_debug("read time %04d.%02d.%02d %02d:%02d:%02d\n",
147 1900 + rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
148 rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
150 rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
151 rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
152 rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
153 rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
154 rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
155 rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
157 rtc_tm->tm_year += 100;
158 rtc_tm->tm_mon -= 1;
160 return rtc_valid_tm(rtc_tm);
163 static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
165 void __iomem *base = s3c_rtc_base;
166 int year = tm->tm_year - 100;
168 pr_debug("set time %04d.%02d.%02d %02d:%02d:%02d\n",
169 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
170 tm->tm_hour, tm->tm_min, tm->tm_sec);
172 /* we get around y2k by simply not supporting it */
174 if (year < 0 || year >= 100) {
175 dev_err(dev, "rtc only supports 100 years\n");
176 return -EINVAL;
179 writeb(bin2bcd(tm->tm_sec), base + S3C2410_RTCSEC);
180 writeb(bin2bcd(tm->tm_min), base + S3C2410_RTCMIN);
181 writeb(bin2bcd(tm->tm_hour), base + S3C2410_RTCHOUR);
182 writeb(bin2bcd(tm->tm_mday), base + S3C2410_RTCDATE);
183 writeb(bin2bcd(tm->tm_mon + 1), base + S3C2410_RTCMON);
184 writeb(bin2bcd(year), base + S3C2410_RTCYEAR);
186 return 0;
189 static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
191 struct rtc_time *alm_tm = &alrm->time;
192 void __iomem *base = s3c_rtc_base;
193 unsigned int alm_en;
195 alm_tm->tm_sec = readb(base + S3C2410_ALMSEC);
196 alm_tm->tm_min = readb(base + S3C2410_ALMMIN);
197 alm_tm->tm_hour = readb(base + S3C2410_ALMHOUR);
198 alm_tm->tm_mon = readb(base + S3C2410_ALMMON);
199 alm_tm->tm_mday = readb(base + S3C2410_ALMDATE);
200 alm_tm->tm_year = readb(base + S3C2410_ALMYEAR);
202 alm_en = readb(base + S3C2410_RTCALM);
204 alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;
206 pr_debug("read alarm %d, %04d.%02d.%02d %02d:%02d:%02d\n",
207 alm_en,
208 1900 + alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
209 alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
212 /* decode the alarm enable field */
214 if (alm_en & S3C2410_RTCALM_SECEN)
215 alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
216 else
217 alm_tm->tm_sec = -1;
219 if (alm_en & S3C2410_RTCALM_MINEN)
220 alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
221 else
222 alm_tm->tm_min = -1;
224 if (alm_en & S3C2410_RTCALM_HOUREN)
225 alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
226 else
227 alm_tm->tm_hour = -1;
229 if (alm_en & S3C2410_RTCALM_DAYEN)
230 alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);
231 else
232 alm_tm->tm_mday = -1;
234 if (alm_en & S3C2410_RTCALM_MONEN) {
235 alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon);
236 alm_tm->tm_mon -= 1;
237 } else {
238 alm_tm->tm_mon = -1;
241 if (alm_en & S3C2410_RTCALM_YEAREN)
242 alm_tm->tm_year = bcd2bin(alm_tm->tm_year);
243 else
244 alm_tm->tm_year = -1;
246 return 0;
249 static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
251 struct rtc_time *tm = &alrm->time;
252 void __iomem *base = s3c_rtc_base;
253 unsigned int alrm_en;
255 pr_debug("s3c_rtc_setalarm: %d, %04d.%02d.%02d %02d:%02d:%02d\n",
256 alrm->enabled,
257 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
258 tm->tm_hour, tm->tm_min, tm->tm_sec);
261 alrm_en = readb(base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
262 writeb(0x00, base + S3C2410_RTCALM);
264 if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
265 alrm_en |= S3C2410_RTCALM_SECEN;
266 writeb(bin2bcd(tm->tm_sec), base + S3C2410_ALMSEC);
269 if (tm->tm_min < 60 && tm->tm_min >= 0) {
270 alrm_en |= S3C2410_RTCALM_MINEN;
271 writeb(bin2bcd(tm->tm_min), base + S3C2410_ALMMIN);
274 if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
275 alrm_en |= S3C2410_RTCALM_HOUREN;
276 writeb(bin2bcd(tm->tm_hour), base + S3C2410_ALMHOUR);
279 pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
281 writeb(alrm_en, base + S3C2410_RTCALM);
283 s3c_rtc_setaie(dev, alrm->enabled);
285 return 0;
288 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
290 unsigned int ticnt;
292 if (s3c_rtc_cpu_type == TYPE_S3C64XX) {
293 ticnt = readw(s3c_rtc_base + S3C2410_RTCCON);
294 ticnt &= S3C64XX_RTCCON_TICEN;
295 } else {
296 ticnt = readb(s3c_rtc_base + S3C2410_TICNT);
297 ticnt &= S3C2410_TICNT_ENABLE;
300 seq_printf(seq, "periodic_IRQ\t: %s\n", ticnt ? "yes" : "no");
301 return 0;
304 static int s3c_rtc_open(struct device *dev)
306 struct platform_device *pdev = to_platform_device(dev);
307 struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
308 int ret;
310 ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq,
311 IRQF_DISABLED, "s3c2410-rtc alarm", rtc_dev);
313 if (ret) {
314 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret);
315 return ret;
318 ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq,
319 IRQF_DISABLED, "s3c2410-rtc tick", rtc_dev);
321 if (ret) {
322 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret);
323 goto tick_err;
326 return ret;
328 tick_err:
329 free_irq(s3c_rtc_alarmno, rtc_dev);
330 return ret;
333 static void s3c_rtc_release(struct device *dev)
335 struct platform_device *pdev = to_platform_device(dev);
336 struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
338 /* do not clear AIE here, it may be needed for wake */
340 free_irq(s3c_rtc_alarmno, rtc_dev);
341 free_irq(s3c_rtc_tickno, rtc_dev);
344 static const struct rtc_class_ops s3c_rtcops = {
345 .open = s3c_rtc_open,
346 .release = s3c_rtc_release,
347 .read_time = s3c_rtc_gettime,
348 .set_time = s3c_rtc_settime,
349 .read_alarm = s3c_rtc_getalarm,
350 .set_alarm = s3c_rtc_setalarm,
351 .proc = s3c_rtc_proc,
352 .alarm_irq_enable = s3c_rtc_setaie,
355 static void s3c_rtc_enable(struct platform_device *pdev, int en)
357 void __iomem *base = s3c_rtc_base;
358 unsigned int tmp;
360 if (s3c_rtc_base == NULL)
361 return;
363 if (!en) {
364 tmp = readw(base + S3C2410_RTCCON);
365 if (s3c_rtc_cpu_type == TYPE_S3C64XX)
366 tmp &= ~S3C64XX_RTCCON_TICEN;
367 tmp &= ~S3C2410_RTCCON_RTCEN;
368 writew(tmp, base + S3C2410_RTCCON);
370 if (s3c_rtc_cpu_type == TYPE_S3C2410) {
371 tmp = readb(base + S3C2410_TICNT);
372 tmp &= ~S3C2410_TICNT_ENABLE;
373 writeb(tmp, base + S3C2410_TICNT);
375 } else {
376 /* re-enable the device, and check it is ok */
378 if ((readw(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0) {
379 dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
381 tmp = readw(base + S3C2410_RTCCON);
382 writew(tmp | S3C2410_RTCCON_RTCEN,
383 base + S3C2410_RTCCON);
386 if ((readw(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)) {
387 dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n");
389 tmp = readw(base + S3C2410_RTCCON);
390 writew(tmp & ~S3C2410_RTCCON_CNTSEL,
391 base + S3C2410_RTCCON);
394 if ((readw(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)) {
395 dev_info(&pdev->dev, "removing RTCCON_CLKRST\n");
397 tmp = readw(base + S3C2410_RTCCON);
398 writew(tmp & ~S3C2410_RTCCON_CLKRST,
399 base + S3C2410_RTCCON);
404 static int __devexit s3c_rtc_remove(struct platform_device *dev)
406 struct rtc_device *rtc = platform_get_drvdata(dev);
408 platform_set_drvdata(dev, NULL);
409 rtc_device_unregister(rtc);
411 s3c_rtc_setaie(&dev->dev, 0);
413 clk_disable(rtc_clk);
414 clk_put(rtc_clk);
415 rtc_clk = NULL;
417 iounmap(s3c_rtc_base);
418 release_resource(s3c_rtc_mem);
419 kfree(s3c_rtc_mem);
421 return 0;
424 static int __devinit s3c_rtc_probe(struct platform_device *pdev)
426 struct rtc_device *rtc;
427 struct rtc_time rtc_tm;
428 struct resource *res;
429 int ret;
431 pr_debug("%s: probe=%p\n", __func__, pdev);
433 /* find the IRQs */
435 s3c_rtc_tickno = platform_get_irq(pdev, 1);
436 if (s3c_rtc_tickno < 0) {
437 dev_err(&pdev->dev, "no irq for rtc tick\n");
438 return -ENOENT;
441 s3c_rtc_alarmno = platform_get_irq(pdev, 0);
442 if (s3c_rtc_alarmno < 0) {
443 dev_err(&pdev->dev, "no irq for alarm\n");
444 return -ENOENT;
447 pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
448 s3c_rtc_tickno, s3c_rtc_alarmno);
450 /* get the memory region */
452 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
453 if (res == NULL) {
454 dev_err(&pdev->dev, "failed to get memory region resource\n");
455 return -ENOENT;
458 s3c_rtc_mem = request_mem_region(res->start,
459 res->end-res->start+1,
460 pdev->name);
462 if (s3c_rtc_mem == NULL) {
463 dev_err(&pdev->dev, "failed to reserve memory region\n");
464 ret = -ENOENT;
465 goto err_nores;
468 s3c_rtc_base = ioremap(res->start, res->end - res->start + 1);
469 if (s3c_rtc_base == NULL) {
470 dev_err(&pdev->dev, "failed ioremap()\n");
471 ret = -EINVAL;
472 goto err_nomap;
475 rtc_clk = clk_get(&pdev->dev, "rtc");
476 if (IS_ERR(rtc_clk)) {
477 dev_err(&pdev->dev, "failed to find rtc clock source\n");
478 ret = PTR_ERR(rtc_clk);
479 rtc_clk = NULL;
480 goto err_clk;
483 clk_enable(rtc_clk);
485 /* check to see if everything is setup correctly */
487 s3c_rtc_enable(pdev, 1);
489 pr_debug("s3c2410_rtc: RTCCON=%02x\n",
490 readw(s3c_rtc_base + S3C2410_RTCCON));
492 device_init_wakeup(&pdev->dev, 1);
494 /* register RTC and exit */
496 rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops,
497 THIS_MODULE);
499 if (IS_ERR(rtc)) {
500 dev_err(&pdev->dev, "cannot attach rtc\n");
501 ret = PTR_ERR(rtc);
502 goto err_nortc;
505 s3c_rtc_cpu_type = platform_get_device_id(pdev)->driver_data;
507 /* Check RTC Time */
509 s3c_rtc_gettime(NULL, &rtc_tm);
511 if (rtc_valid_tm(&rtc_tm)) {
512 rtc_tm.tm_year = 100;
513 rtc_tm.tm_mon = 0;
514 rtc_tm.tm_mday = 1;
515 rtc_tm.tm_hour = 0;
516 rtc_tm.tm_min = 0;
517 rtc_tm.tm_sec = 0;
519 s3c_rtc_settime(NULL, &rtc_tm);
521 dev_warn(&pdev->dev, "warning: invalid RTC value so initializing it\n");
524 if (s3c_rtc_cpu_type == TYPE_S3C64XX)
525 rtc->max_user_freq = 32768;
526 else
527 rtc->max_user_freq = 128;
529 platform_set_drvdata(pdev, rtc);
531 s3c_rtc_setfreq(&pdev->dev, 1);
533 return 0;
535 err_nortc:
536 s3c_rtc_enable(pdev, 0);
537 clk_disable(rtc_clk);
538 clk_put(rtc_clk);
540 err_clk:
541 iounmap(s3c_rtc_base);
543 err_nomap:
544 release_resource(s3c_rtc_mem);
546 err_nores:
547 return ret;
550 #ifdef CONFIG_PM
552 /* RTC Power management control */
554 static int ticnt_save, ticnt_en_save;
556 static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state)
558 /* save TICNT for anyone using periodic interrupts */
559 ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT);
560 if (s3c_rtc_cpu_type == TYPE_S3C64XX) {
561 ticnt_en_save = readw(s3c_rtc_base + S3C2410_RTCCON);
562 ticnt_en_save &= S3C64XX_RTCCON_TICEN;
564 s3c_rtc_enable(pdev, 0);
566 if (device_may_wakeup(&pdev->dev) && !wake_en) {
567 if (enable_irq_wake(s3c_rtc_alarmno) == 0)
568 wake_en = true;
569 else
570 dev_err(&pdev->dev, "enable_irq_wake failed\n");
573 return 0;
576 static int s3c_rtc_resume(struct platform_device *pdev)
578 unsigned int tmp;
580 s3c_rtc_enable(pdev, 1);
581 writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT);
582 if (s3c_rtc_cpu_type == TYPE_S3C64XX && ticnt_en_save) {
583 tmp = readw(s3c_rtc_base + S3C2410_RTCCON);
584 writew(tmp | ticnt_en_save, s3c_rtc_base + S3C2410_RTCCON);
587 if (device_may_wakeup(&pdev->dev) && wake_en) {
588 disable_irq_wake(s3c_rtc_alarmno);
589 wake_en = false;
592 return 0;
594 #else
595 #define s3c_rtc_suspend NULL
596 #define s3c_rtc_resume NULL
597 #endif
599 static struct platform_device_id s3c_rtc_driver_ids[] = {
601 .name = "s3c2410-rtc",
602 .driver_data = TYPE_S3C2410,
603 }, {
604 .name = "s3c64xx-rtc",
605 .driver_data = TYPE_S3C64XX,
610 MODULE_DEVICE_TABLE(platform, s3c_rtc_driver_ids);
612 static struct platform_driver s3c_rtc_driver = {
613 .probe = s3c_rtc_probe,
614 .remove = __devexit_p(s3c_rtc_remove),
615 .suspend = s3c_rtc_suspend,
616 .resume = s3c_rtc_resume,
617 .id_table = s3c_rtc_driver_ids,
618 .driver = {
619 .name = "s3c-rtc",
620 .owner = THIS_MODULE,
624 static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n";
626 static int __init s3c_rtc_init(void)
628 printk(banner);
629 return platform_driver_register(&s3c_rtc_driver);
632 static void __exit s3c_rtc_exit(void)
634 platform_driver_unregister(&s3c_rtc_driver);
637 module_init(s3c_rtc_init);
638 module_exit(s3c_rtc_exit);
640 MODULE_DESCRIPTION("Samsung S3C RTC Driver");
641 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
642 MODULE_LICENSE("GPL");
643 MODULE_ALIAS("platform:s3c2410-rtc");