Merge remote-tracking branch 'slab/for-next'
[linux-2.6/next.git] / drivers / rtc / rtc-s3c.c
blob9329dbb9ebabeafc5bbfe5f0b1123a5ed5bac33d
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 clk_enable(rtc_clk);
61 rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
63 if (s3c_rtc_cpu_type == TYPE_S3C64XX)
64 writeb(S3C2410_INTP_ALM, s3c_rtc_base + S3C2410_INTP);
66 clk_disable(rtc_clk);
67 return IRQ_HANDLED;
70 static irqreturn_t s3c_rtc_tickirq(int irq, void *id)
72 struct rtc_device *rdev = id;
74 clk_enable(rtc_clk);
75 rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF);
77 if (s3c_rtc_cpu_type == TYPE_S3C64XX)
78 writeb(S3C2410_INTP_TIC, s3c_rtc_base + S3C2410_INTP);
80 clk_disable(rtc_clk);
81 return IRQ_HANDLED;
84 /* Update control registers */
85 static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
87 unsigned int tmp;
89 pr_debug("%s: aie=%d\n", __func__, enabled);
91 clk_enable(rtc_clk);
92 tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
94 if (enabled)
95 tmp |= S3C2410_RTCALM_ALMEN;
97 writeb(tmp, s3c_rtc_base + S3C2410_RTCALM);
98 clk_disable(rtc_clk);
100 return 0;
103 static int s3c_rtc_setfreq(struct device *dev, int freq)
105 struct platform_device *pdev = to_platform_device(dev);
106 struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
107 unsigned int tmp = 0;
109 if (!is_power_of_2(freq))
110 return -EINVAL;
112 clk_enable(rtc_clk);
113 spin_lock_irq(&s3c_rtc_pie_lock);
115 if (s3c_rtc_cpu_type == TYPE_S3C2410) {
116 tmp = readb(s3c_rtc_base + S3C2410_TICNT);
117 tmp &= S3C2410_TICNT_ENABLE;
120 tmp |= (rtc_dev->max_user_freq / freq)-1;
122 writel(tmp, s3c_rtc_base + S3C2410_TICNT);
123 spin_unlock_irq(&s3c_rtc_pie_lock);
124 clk_disable(rtc_clk);
126 return 0;
129 /* Time read/write */
131 static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
133 unsigned int have_retried = 0;
134 void __iomem *base = s3c_rtc_base;
136 clk_enable(rtc_clk);
137 retry_get_time:
138 rtc_tm->tm_min = readb(base + S3C2410_RTCMIN);
139 rtc_tm->tm_hour = readb(base + S3C2410_RTCHOUR);
140 rtc_tm->tm_mday = readb(base + S3C2410_RTCDATE);
141 rtc_tm->tm_mon = readb(base + S3C2410_RTCMON);
142 rtc_tm->tm_year = readb(base + S3C2410_RTCYEAR);
143 rtc_tm->tm_sec = readb(base + S3C2410_RTCSEC);
145 /* the only way to work out wether the system was mid-update
146 * when we read it is to check the second counter, and if it
147 * is zero, then we re-try the entire read
150 if (rtc_tm->tm_sec == 0 && !have_retried) {
151 have_retried = 1;
152 goto retry_get_time;
155 pr_debug("read time %04d.%02d.%02d %02d:%02d:%02d\n",
156 1900 + rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
157 rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
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);
166 rtc_tm->tm_year += 100;
167 rtc_tm->tm_mon -= 1;
169 clk_disable(rtc_clk);
170 return rtc_valid_tm(rtc_tm);
173 static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
175 void __iomem *base = s3c_rtc_base;
176 int year = tm->tm_year - 100;
178 clk_enable(rtc_clk);
179 pr_debug("set time %04d.%02d.%02d %02d:%02d:%02d\n",
180 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
181 tm->tm_hour, tm->tm_min, tm->tm_sec);
183 /* we get around y2k by simply not supporting it */
185 if (year < 0 || year >= 100) {
186 dev_err(dev, "rtc only supports 100 years\n");
187 return -EINVAL;
190 writeb(bin2bcd(tm->tm_sec), base + S3C2410_RTCSEC);
191 writeb(bin2bcd(tm->tm_min), base + S3C2410_RTCMIN);
192 writeb(bin2bcd(tm->tm_hour), base + S3C2410_RTCHOUR);
193 writeb(bin2bcd(tm->tm_mday), base + S3C2410_RTCDATE);
194 writeb(bin2bcd(tm->tm_mon + 1), base + S3C2410_RTCMON);
195 writeb(bin2bcd(year), base + S3C2410_RTCYEAR);
196 clk_disable(rtc_clk);
198 return 0;
201 static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
203 struct rtc_time *alm_tm = &alrm->time;
204 void __iomem *base = s3c_rtc_base;
205 unsigned int alm_en;
207 clk_enable(rtc_clk);
208 alm_tm->tm_sec = readb(base + S3C2410_ALMSEC);
209 alm_tm->tm_min = readb(base + S3C2410_ALMMIN);
210 alm_tm->tm_hour = readb(base + S3C2410_ALMHOUR);
211 alm_tm->tm_mon = readb(base + S3C2410_ALMMON);
212 alm_tm->tm_mday = readb(base + S3C2410_ALMDATE);
213 alm_tm->tm_year = readb(base + S3C2410_ALMYEAR);
215 alm_en = readb(base + S3C2410_RTCALM);
217 alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;
219 pr_debug("read alarm %d, %04d.%02d.%02d %02d:%02d:%02d\n",
220 alm_en,
221 1900 + alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
222 alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
225 /* decode the alarm enable field */
227 if (alm_en & S3C2410_RTCALM_SECEN)
228 alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
229 else
230 alm_tm->tm_sec = -1;
232 if (alm_en & S3C2410_RTCALM_MINEN)
233 alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
234 else
235 alm_tm->tm_min = -1;
237 if (alm_en & S3C2410_RTCALM_HOUREN)
238 alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
239 else
240 alm_tm->tm_hour = -1;
242 if (alm_en & S3C2410_RTCALM_DAYEN)
243 alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);
244 else
245 alm_tm->tm_mday = -1;
247 if (alm_en & S3C2410_RTCALM_MONEN) {
248 alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon);
249 alm_tm->tm_mon -= 1;
250 } else {
251 alm_tm->tm_mon = -1;
254 if (alm_en & S3C2410_RTCALM_YEAREN)
255 alm_tm->tm_year = bcd2bin(alm_tm->tm_year);
256 else
257 alm_tm->tm_year = -1;
259 clk_disable(rtc_clk);
260 return 0;
263 static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
265 struct rtc_time *tm = &alrm->time;
266 void __iomem *base = s3c_rtc_base;
267 unsigned int alrm_en;
269 clk_enable(rtc_clk);
270 pr_debug("s3c_rtc_setalarm: %d, %04d.%02d.%02d %02d:%02d:%02d\n",
271 alrm->enabled,
272 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
273 tm->tm_hour, tm->tm_min, tm->tm_sec);
276 alrm_en = readb(base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
277 writeb(0x00, base + S3C2410_RTCALM);
279 if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
280 alrm_en |= S3C2410_RTCALM_SECEN;
281 writeb(bin2bcd(tm->tm_sec), base + S3C2410_ALMSEC);
284 if (tm->tm_min < 60 && tm->tm_min >= 0) {
285 alrm_en |= S3C2410_RTCALM_MINEN;
286 writeb(bin2bcd(tm->tm_min), base + S3C2410_ALMMIN);
289 if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
290 alrm_en |= S3C2410_RTCALM_HOUREN;
291 writeb(bin2bcd(tm->tm_hour), base + S3C2410_ALMHOUR);
294 pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
296 writeb(alrm_en, base + S3C2410_RTCALM);
298 s3c_rtc_setaie(dev, alrm->enabled);
300 clk_disable(rtc_clk);
301 return 0;
304 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
306 unsigned int ticnt;
308 clk_enable(rtc_clk);
309 if (s3c_rtc_cpu_type == TYPE_S3C64XX) {
310 ticnt = readw(s3c_rtc_base + S3C2410_RTCCON);
311 ticnt &= S3C64XX_RTCCON_TICEN;
312 } else {
313 ticnt = readb(s3c_rtc_base + S3C2410_TICNT);
314 ticnt &= S3C2410_TICNT_ENABLE;
317 seq_printf(seq, "periodic_IRQ\t: %s\n", ticnt ? "yes" : "no");
318 clk_disable(rtc_clk);
319 return 0;
322 static int s3c_rtc_open(struct device *dev)
324 struct platform_device *pdev = to_platform_device(dev);
325 struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
326 int ret;
328 ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq,
329 IRQF_DISABLED, "s3c2410-rtc alarm", rtc_dev);
331 if (ret) {
332 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret);
333 return ret;
336 ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq,
337 IRQF_DISABLED, "s3c2410-rtc tick", rtc_dev);
339 if (ret) {
340 dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret);
341 goto tick_err;
344 return ret;
346 tick_err:
347 free_irq(s3c_rtc_alarmno, rtc_dev);
348 return ret;
351 static void s3c_rtc_release(struct device *dev)
353 struct platform_device *pdev = to_platform_device(dev);
354 struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
356 /* do not clear AIE here, it may be needed for wake */
358 free_irq(s3c_rtc_alarmno, rtc_dev);
359 free_irq(s3c_rtc_tickno, rtc_dev);
362 static const struct rtc_class_ops s3c_rtcops = {
363 .open = s3c_rtc_open,
364 .release = s3c_rtc_release,
365 .read_time = s3c_rtc_gettime,
366 .set_time = s3c_rtc_settime,
367 .read_alarm = s3c_rtc_getalarm,
368 .set_alarm = s3c_rtc_setalarm,
369 .proc = s3c_rtc_proc,
370 .alarm_irq_enable = s3c_rtc_setaie,
373 static void s3c_rtc_enable(struct platform_device *pdev, int en)
375 void __iomem *base = s3c_rtc_base;
376 unsigned int tmp;
378 if (s3c_rtc_base == NULL)
379 return;
381 clk_enable(rtc_clk);
382 if (!en) {
383 tmp = readw(base + S3C2410_RTCCON);
384 if (s3c_rtc_cpu_type == TYPE_S3C64XX)
385 tmp &= ~S3C64XX_RTCCON_TICEN;
386 tmp &= ~S3C2410_RTCCON_RTCEN;
387 writew(tmp, base + S3C2410_RTCCON);
389 if (s3c_rtc_cpu_type == TYPE_S3C2410) {
390 tmp = readb(base + S3C2410_TICNT);
391 tmp &= ~S3C2410_TICNT_ENABLE;
392 writeb(tmp, base + S3C2410_TICNT);
394 } else {
395 /* re-enable the device, and check it is ok */
397 if ((readw(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0) {
398 dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
400 tmp = readw(base + S3C2410_RTCCON);
401 writew(tmp | S3C2410_RTCCON_RTCEN,
402 base + S3C2410_RTCCON);
405 if ((readw(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)) {
406 dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n");
408 tmp = readw(base + S3C2410_RTCCON);
409 writew(tmp & ~S3C2410_RTCCON_CNTSEL,
410 base + S3C2410_RTCCON);
413 if ((readw(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)) {
414 dev_info(&pdev->dev, "removing RTCCON_CLKRST\n");
416 tmp = readw(base + S3C2410_RTCCON);
417 writew(tmp & ~S3C2410_RTCCON_CLKRST,
418 base + S3C2410_RTCCON);
421 clk_disable(rtc_clk);
424 static int __devexit s3c_rtc_remove(struct platform_device *dev)
426 struct rtc_device *rtc = platform_get_drvdata(dev);
428 platform_set_drvdata(dev, NULL);
429 rtc_device_unregister(rtc);
431 s3c_rtc_setaie(&dev->dev, 0);
433 clk_put(rtc_clk);
434 rtc_clk = NULL;
436 iounmap(s3c_rtc_base);
437 release_resource(s3c_rtc_mem);
438 kfree(s3c_rtc_mem);
440 return 0;
443 static int __devinit s3c_rtc_probe(struct platform_device *pdev)
445 struct rtc_device *rtc;
446 struct rtc_time rtc_tm;
447 struct resource *res;
448 int ret;
450 pr_debug("%s: probe=%p\n", __func__, pdev);
452 /* find the IRQs */
454 s3c_rtc_tickno = platform_get_irq(pdev, 1);
455 if (s3c_rtc_tickno < 0) {
456 dev_err(&pdev->dev, "no irq for rtc tick\n");
457 return -ENOENT;
460 s3c_rtc_alarmno = platform_get_irq(pdev, 0);
461 if (s3c_rtc_alarmno < 0) {
462 dev_err(&pdev->dev, "no irq for alarm\n");
463 return -ENOENT;
466 pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
467 s3c_rtc_tickno, s3c_rtc_alarmno);
469 /* get the memory region */
471 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
472 if (res == NULL) {
473 dev_err(&pdev->dev, "failed to get memory region resource\n");
474 return -ENOENT;
477 s3c_rtc_mem = request_mem_region(res->start, resource_size(res),
478 pdev->name);
480 if (s3c_rtc_mem == NULL) {
481 dev_err(&pdev->dev, "failed to reserve memory region\n");
482 ret = -ENOENT;
483 goto err_nores;
486 s3c_rtc_base = ioremap(res->start, resource_size(res));
487 if (s3c_rtc_base == NULL) {
488 dev_err(&pdev->dev, "failed ioremap()\n");
489 ret = -EINVAL;
490 goto err_nomap;
493 rtc_clk = clk_get(&pdev->dev, "rtc");
494 if (IS_ERR(rtc_clk)) {
495 dev_err(&pdev->dev, "failed to find rtc clock source\n");
496 ret = PTR_ERR(rtc_clk);
497 rtc_clk = NULL;
498 goto err_clk;
501 clk_enable(rtc_clk);
503 /* check to see if everything is setup correctly */
505 s3c_rtc_enable(pdev, 1);
507 pr_debug("s3c2410_rtc: RTCCON=%02x\n",
508 readw(s3c_rtc_base + S3C2410_RTCCON));
510 device_init_wakeup(&pdev->dev, 1);
512 /* register RTC and exit */
514 rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops,
515 THIS_MODULE);
517 if (IS_ERR(rtc)) {
518 dev_err(&pdev->dev, "cannot attach rtc\n");
519 ret = PTR_ERR(rtc);
520 goto err_nortc;
523 s3c_rtc_cpu_type = platform_get_device_id(pdev)->driver_data;
525 /* Check RTC Time */
527 s3c_rtc_gettime(NULL, &rtc_tm);
529 if (rtc_valid_tm(&rtc_tm)) {
530 rtc_tm.tm_year = 100;
531 rtc_tm.tm_mon = 0;
532 rtc_tm.tm_mday = 1;
533 rtc_tm.tm_hour = 0;
534 rtc_tm.tm_min = 0;
535 rtc_tm.tm_sec = 0;
537 s3c_rtc_settime(NULL, &rtc_tm);
539 dev_warn(&pdev->dev, "warning: invalid RTC value so initializing it\n");
542 if (s3c_rtc_cpu_type == TYPE_S3C64XX)
543 rtc->max_user_freq = 32768;
544 else
545 rtc->max_user_freq = 128;
547 platform_set_drvdata(pdev, rtc);
549 s3c_rtc_setfreq(&pdev->dev, 1);
551 clk_disable(rtc_clk);
553 return 0;
555 err_nortc:
556 s3c_rtc_enable(pdev, 0);
557 clk_disable(rtc_clk);
558 clk_put(rtc_clk);
560 err_clk:
561 iounmap(s3c_rtc_base);
563 err_nomap:
564 release_resource(s3c_rtc_mem);
566 err_nores:
567 return ret;
570 #ifdef CONFIG_PM
572 /* RTC Power management control */
574 static int ticnt_save, ticnt_en_save;
576 static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state)
578 clk_enable(rtc_clk);
579 /* save TICNT for anyone using periodic interrupts */
580 ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT);
581 if (s3c_rtc_cpu_type == TYPE_S3C64XX) {
582 ticnt_en_save = readw(s3c_rtc_base + S3C2410_RTCCON);
583 ticnt_en_save &= S3C64XX_RTCCON_TICEN;
585 s3c_rtc_enable(pdev, 0);
587 if (device_may_wakeup(&pdev->dev) && !wake_en) {
588 if (enable_irq_wake(s3c_rtc_alarmno) == 0)
589 wake_en = true;
590 else
591 dev_err(&pdev->dev, "enable_irq_wake failed\n");
593 clk_disable(rtc_clk);
595 return 0;
598 static int s3c_rtc_resume(struct platform_device *pdev)
600 unsigned int tmp;
602 clk_enable(rtc_clk);
603 s3c_rtc_enable(pdev, 1);
604 writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT);
605 if (s3c_rtc_cpu_type == TYPE_S3C64XX && ticnt_en_save) {
606 tmp = readw(s3c_rtc_base + S3C2410_RTCCON);
607 writew(tmp | ticnt_en_save, s3c_rtc_base + S3C2410_RTCCON);
610 if (device_may_wakeup(&pdev->dev) && wake_en) {
611 disable_irq_wake(s3c_rtc_alarmno);
612 wake_en = false;
614 clk_disable(rtc_clk);
616 return 0;
618 #else
619 #define s3c_rtc_suspend NULL
620 #define s3c_rtc_resume NULL
621 #endif
623 static struct platform_device_id s3c_rtc_driver_ids[] = {
625 .name = "s3c2410-rtc",
626 .driver_data = TYPE_S3C2410,
627 }, {
628 .name = "s3c64xx-rtc",
629 .driver_data = TYPE_S3C64XX,
634 MODULE_DEVICE_TABLE(platform, s3c_rtc_driver_ids);
636 static struct platform_driver s3c_rtc_driver = {
637 .probe = s3c_rtc_probe,
638 .remove = __devexit_p(s3c_rtc_remove),
639 .suspend = s3c_rtc_suspend,
640 .resume = s3c_rtc_resume,
641 .id_table = s3c_rtc_driver_ids,
642 .driver = {
643 .name = "s3c-rtc",
644 .owner = THIS_MODULE,
648 static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n";
650 static int __init s3c_rtc_init(void)
652 printk(banner);
653 return platform_driver_register(&s3c_rtc_driver);
656 static void __exit s3c_rtc_exit(void)
658 platform_driver_unregister(&s3c_rtc_driver);
661 module_init(s3c_rtc_init);
662 module_exit(s3c_rtc_exit);
664 MODULE_DESCRIPTION("Samsung S3C RTC Driver");
665 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
666 MODULE_LICENSE("GPL");
667 MODULE_ALIAS("platform:s3c2410-rtc");