1/* drivers/rtc/rtc-s3c.c
2 *
3 * Copyright (c) 2004,2006 Simtec Electronics
4 *	Ben Dooks, <ben@simtec.co.uk>
5 *	http://armlinux.simtec.co.uk/
6 *
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.
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
24#include <asm/hardware.h>
25#include <asm/uaccess.h>
26#include <asm/io.h>
27#include <asm/irq.h>
28#include <asm/rtc.h>
29
30#include <asm/mach/time.h>
31
32#include <asm/arch/regs-rtc.h>
33
34/* I have yet to find an S3C implementation with more than one
35 * of these rtc blocks in */
36
37static struct resource *s3c_rtc_mem;
38
39static void __iomem *s3c_rtc_base;
40static int s3c_rtc_alarmno = NO_IRQ;
41static int s3c_rtc_tickno  = NO_IRQ;
42static int s3c_rtc_freq    = 1;
43
44static DEFINE_SPINLOCK(s3c_rtc_pie_lock);
45static unsigned int tick_count;
46
47/* IRQ Handlers */
48
49static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
50{
51	struct rtc_device *rdev = id;
52
53	rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
54	return IRQ_HANDLED;
55}
56
57static irqreturn_t s3c_rtc_tickirq(int irq, void *id)
58{
59	struct rtc_device *rdev = id;
60
61	rtc_update_irq(rdev, tick_count++, RTC_PF | RTC_IRQF);
62	return IRQ_HANDLED;
63}
64
65/* Update control registers */
66static void s3c_rtc_setaie(int to)
67{
68	unsigned int tmp;
69
70	pr_debug("%s: aie=%d\n", __FUNCTION__, to);
71
72	tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
73
74	if (to)
75		tmp |= S3C2410_RTCALM_ALMEN;
76
77	writeb(tmp, s3c_rtc_base + S3C2410_RTCALM);
78}
79
80static void s3c_rtc_setpie(int to)
81{
82	unsigned int tmp;
83
84	pr_debug("%s: pie=%d\n", __FUNCTION__, to);
85
86	spin_lock_irq(&s3c_rtc_pie_lock);
87	tmp = readb(s3c_rtc_base + S3C2410_TICNT) & ~S3C2410_TICNT_ENABLE;
88
89	if (to)
90		tmp |= S3C2410_TICNT_ENABLE;
91
92	writeb(tmp, s3c_rtc_base + S3C2410_TICNT);
93	spin_unlock_irq(&s3c_rtc_pie_lock);
94}
95
96static void s3c_rtc_setfreq(int freq)
97{
98	unsigned int tmp;
99
100	spin_lock_irq(&s3c_rtc_pie_lock);
101	tmp = readb(s3c_rtc_base + S3C2410_TICNT) & S3C2410_TICNT_ENABLE;
102
103	s3c_rtc_freq = freq;
104
105	tmp |= (128 / freq)-1;
106
107	writeb(tmp, s3c_rtc_base + S3C2410_TICNT);
108	spin_unlock_irq(&s3c_rtc_pie_lock);
109}
110
111/* Time read/write */
112
113static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
114{
115	unsigned int have_retried = 0;
116	void __iomem *base = s3c_rtc_base;
117
118 retry_get_time:
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);
125
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
129	 */
130
131	if (rtc_tm->tm_sec == 0 && !have_retried) {
132		have_retried = 1;
133		goto retry_get_time;
134	}
135
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);
139
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);
146
147	rtc_tm->tm_year += 100;
148	rtc_tm->tm_mon -= 1;
149
150	return 0;
151}
152
153static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
154{
155	void __iomem *base = s3c_rtc_base;
156	int year = tm->tm_year - 100;
157
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);
161
162	/* we get around y2k by simply not supporting it */
163
164	if (year < 0 || year >= 100) {
165		dev_err(dev, "rtc only supports 100 years\n");
166		return -EINVAL;
167	}
168
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);
175
176	return 0;
177}
178
179static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
180{
181	struct rtc_time *alm_tm = &alrm->time;
182	void __iomem *base = s3c_rtc_base;
183	unsigned int alm_en;
184
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);
191
192	alm_en = readb(base + S3C2410_RTCALM);
193
194	alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;
195
196	pr_debug("read alarm %02x %02x.%02x.%02x %02x/%02x/%02x\n",
197		 alm_en,
198		 alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
199		 alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
200
201
202	/* decode the alarm enable field */
203
204	if (alm_en & S3C2410_RTCALM_SECEN)
205		BCD_TO_BIN(alm_tm->tm_sec);
206	else
207		alm_tm->tm_sec = 0xff;
208
209	if (alm_en & S3C2410_RTCALM_MINEN)
210		BCD_TO_BIN(alm_tm->tm_min);
211	else
212		alm_tm->tm_min = 0xff;
213
214	if (alm_en & S3C2410_RTCALM_HOUREN)
215		BCD_TO_BIN(alm_tm->tm_hour);
216	else
217		alm_tm->tm_hour = 0xff;
218
219	if (alm_en & S3C2410_RTCALM_DAYEN)
220		BCD_TO_BIN(alm_tm->tm_mday);
221	else
222		alm_tm->tm_mday = 0xff;
223
224	if (alm_en & S3C2410_RTCALM_MONEN) {
225		BCD_TO_BIN(alm_tm->tm_mon);
226		alm_tm->tm_mon -= 1;
227	} else {
228		alm_tm->tm_mon = 0xff;
229	}
230
231	if (alm_en & S3C2410_RTCALM_YEAREN)
232		BCD_TO_BIN(alm_tm->tm_year);
233	else
234		alm_tm->tm_year = 0xffff;
235
236	return 0;
237}
238
239static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
240{
241	struct rtc_time *tm = &alrm->time;
242	void __iomem *base = s3c_rtc_base;
243	unsigned int alrm_en;
244
245	pr_debug("s3c_rtc_setalarm: %d, %02x/%02x/%02x %02x.%02x.%02x\n",
246		 alrm->enabled,
247		 tm->tm_mday & 0xff, tm->tm_mon & 0xff, tm->tm_year & 0xff,
248		 tm->tm_hour & 0xff, tm->tm_min & 0xff, tm->tm_sec);
249
250
251	alrm_en = readb(base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
252	writeb(0x00, base + S3C2410_RTCALM);
253
254	if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
255		alrm_en |= S3C2410_RTCALM_SECEN;
256		writeb(BIN2BCD(tm->tm_sec), base + S3C2410_ALMSEC);
257	}
258
259	if (tm->tm_min < 60 && tm->tm_min >= 0) {
260		alrm_en |= S3C2410_RTCALM_MINEN;
261		writeb(BIN2BCD(tm->tm_min), base + S3C2410_ALMMIN);
262	}
263
264	if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
265		alrm_en |= S3C2410_RTCALM_HOUREN;
266		writeb(BIN2BCD(tm->tm_hour), base + S3C2410_ALMHOUR);
267	}
268
269	pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
270
271	writeb(alrm_en, base + S3C2410_RTCALM);
272
273	if (0) {
274		alrm_en = readb(base + S3C2410_RTCALM);
275		alrm_en &= ~S3C2410_RTCALM_ALMEN;
276		writeb(alrm_en, base + S3C2410_RTCALM);
277		disable_irq_wake(s3c_rtc_alarmno);
278	}
279
280	if (alrm->enabled)
281		enable_irq_wake(s3c_rtc_alarmno);
282	else
283		disable_irq_wake(s3c_rtc_alarmno);
284
285	return 0;
286}
287
288static int s3c_rtc_ioctl(struct device *dev,
289			 unsigned int cmd, unsigned long arg)
290{
291	unsigned int ret = -ENOIOCTLCMD;
292
293	switch (cmd) {
294	case RTC_AIE_OFF:
295	case RTC_AIE_ON:
296		s3c_rtc_setaie((cmd == RTC_AIE_ON) ? 1 : 0);
297		ret = 0;
298		break;
299
300	case RTC_PIE_OFF:
301	case RTC_PIE_ON:
302		tick_count = 0;
303		s3c_rtc_setpie((cmd == RTC_PIE_ON) ? 1 : 0);
304		ret = 0;
305		break;
306
307	case RTC_IRQP_READ:
308		ret = put_user(s3c_rtc_freq, (unsigned long __user *)arg);
309		break;
310
311	case RTC_IRQP_SET:
312		/* check for power of 2 */
313
314		if ((arg & (arg-1)) != 0 || arg < 1) {
315			ret = -EINVAL;
316			goto exit;
317		}
318
319		pr_debug("s3c2410_rtc: setting frequency %ld\n", arg);
320
321		s3c_rtc_setfreq(arg);
322		ret = 0;
323		break;
324
325	case RTC_UIE_ON:
326	case RTC_UIE_OFF:
327		ret = -EINVAL;
328	}
329
330 exit:
331	return ret;
332}
333
334static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
335{
336	unsigned int ticnt = readb(s3c_rtc_base + S3C2410_TICNT);
337
338	seq_printf(seq, "periodic_IRQ\t: %s\n",
339		     (ticnt & S3C2410_TICNT_ENABLE) ? "yes" : "no" );
340
341	seq_printf(seq, "periodic_freq\t: %d\n", s3c_rtc_freq);
342
343	return 0;
344}
345
346static int s3c_rtc_open(struct device *dev)
347{
348	struct platform_device *pdev = to_platform_device(dev);
349	struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
350	int ret;
351
352	ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq,
353			  IRQF_DISABLED,  "s3c2410-rtc alarm", rtc_dev);
354
355	if (ret) {
356		dev_err(dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret);
357		return ret;
358	}
359
360	ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq,
361			  IRQF_DISABLED,  "s3c2410-rtc tick", rtc_dev);
362
363	if (ret) {
364		dev_err(dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret);
365		goto tick_err;
366	}
367
368	return ret;
369
370 tick_err:
371	free_irq(s3c_rtc_alarmno, rtc_dev);
372	return ret;
373}
374
375static void s3c_rtc_release(struct device *dev)
376{
377	struct platform_device *pdev = to_platform_device(dev);
378	struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
379
380	/* do not clear AIE here, it may be needed for wake */
381
382	s3c_rtc_setpie(0);
383	free_irq(s3c_rtc_alarmno, rtc_dev);
384	free_irq(s3c_rtc_tickno, rtc_dev);
385}
386
387static const struct rtc_class_ops s3c_rtcops = {
388	.open		= s3c_rtc_open,
389	.release	= s3c_rtc_release,
390	.ioctl		= s3c_rtc_ioctl,
391	.read_time	= s3c_rtc_gettime,
392	.set_time	= s3c_rtc_settime,
393	.read_alarm	= s3c_rtc_getalarm,
394	.set_alarm	= s3c_rtc_setalarm,
395	.proc	        = s3c_rtc_proc,
396};
397
398static void s3c_rtc_enable(struct platform_device *pdev, int en)
399{
400	void __iomem *base = s3c_rtc_base;
401	unsigned int tmp;
402
403	if (s3c_rtc_base == NULL)
404		return;
405
406	if (!en) {
407		tmp = readb(base + S3C2410_RTCCON);
408		writeb(tmp & ~S3C2410_RTCCON_RTCEN, base + S3C2410_RTCCON);
409
410		tmp = readb(base + S3C2410_TICNT);
411		writeb(tmp & ~S3C2410_TICNT_ENABLE, base + S3C2410_TICNT);
412	} else {
413		/* re-enable the device, and check it is ok */
414
415		if ((readb(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0){
416			dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
417
418			tmp = readb(base + S3C2410_RTCCON);
419			writeb(tmp|S3C2410_RTCCON_RTCEN, base+S3C2410_RTCCON);
420		}
421
422		if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)){
423			dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n");
424
425			tmp = readb(base + S3C2410_RTCCON);
426			writeb(tmp& ~S3C2410_RTCCON_CNTSEL, base+S3C2410_RTCCON);
427		}
428
429		if ((readb(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)){
430			dev_info(&pdev->dev, "removing RTCCON_CLKRST\n");
431
432			tmp = readb(base + S3C2410_RTCCON);
433			writeb(tmp & ~S3C2410_RTCCON_CLKRST, base+S3C2410_RTCCON);
434		}
435	}
436}
437
438static int s3c_rtc_remove(struct platform_device *dev)
439{
440	struct rtc_device *rtc = platform_get_drvdata(dev);
441
442	platform_set_drvdata(dev, NULL);
443	rtc_device_unregister(rtc);
444
445	s3c_rtc_setpie(0);
446	s3c_rtc_setaie(0);
447
448	iounmap(s3c_rtc_base);
449	release_resource(s3c_rtc_mem);
450	kfree(s3c_rtc_mem);
451
452	return 0;
453}
454
455static int s3c_rtc_probe(struct platform_device *pdev)
456{
457	struct rtc_device *rtc;
458	struct resource *res;
459	int ret;
460
461	pr_debug("%s: probe=%p\n", __FUNCTION__, pdev);
462
463	/* find the IRQs */
464
465	s3c_rtc_tickno = platform_get_irq(pdev, 1);
466	if (s3c_rtc_tickno < 0) {
467		dev_err(&pdev->dev, "no irq for rtc tick\n");
468		return -ENOENT;
469	}
470
471	s3c_rtc_alarmno = platform_get_irq(pdev, 0);
472	if (s3c_rtc_alarmno < 0) {
473		dev_err(&pdev->dev, "no irq for alarm\n");
474		return -ENOENT;
475	}
476
477	pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
478		 s3c_rtc_tickno, s3c_rtc_alarmno);
479
480	/* get the memory region */
481
482	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
483	if (res == NULL) {
484		dev_err(&pdev->dev, "failed to get memory region resource\n");
485		return -ENOENT;
486	}
487
488	s3c_rtc_mem = request_mem_region(res->start,
489					 res->end-res->start+1,
490					 pdev->name);
491
492	if (s3c_rtc_mem == NULL) {
493		dev_err(&pdev->dev, "failed to reserve memory region\n");
494		ret = -ENOENT;
495		goto err_nores;
496	}
497
498	s3c_rtc_base = ioremap(res->start, res->end - res->start + 1);
499	if (s3c_rtc_base == NULL) {
500		dev_err(&pdev->dev, "failed ioremap()\n");
501		ret = -EINVAL;
502		goto err_nomap;
503	}
504
505	/* check to see if everything is setup correctly */
506
507	s3c_rtc_enable(pdev, 1);
508
509 	pr_debug("s3c2410_rtc: RTCCON=%02x\n",
510		 readb(s3c_rtc_base + S3C2410_RTCCON));
511
512	s3c_rtc_setfreq(s3c_rtc_freq);
513
514	/* register RTC and exit */
515
516	rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops,
517				  THIS_MODULE);
518
519	if (IS_ERR(rtc)) {
520		dev_err(&pdev->dev, "cannot attach rtc\n");
521		ret = PTR_ERR(rtc);
522		goto err_nortc;
523	}
524
525	rtc->max_user_freq = 128;
526
527	platform_set_drvdata(pdev, rtc);
528	return 0;
529
530 err_nortc:
531	s3c_rtc_enable(pdev, 0);
532	iounmap(s3c_rtc_base);
533
534 err_nomap:
535	release_resource(s3c_rtc_mem);
536
537 err_nores:
538	return ret;
539}
540
541#ifdef CONFIG_PM
542
543/* RTC Power management control */
544
545static struct timespec s3c_rtc_delta;
546
547static int ticnt_save;
548
549static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state)
550{
551	/* save TICNT for anyone using periodic interrupts */
552	ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT);
553	s3c_rtc_enable(pdev, 0);
554	return 0;
555}
556
557static int s3c_rtc_resume(struct platform_device *pdev)
558{
559	s3c_rtc_enable(pdev, 1);
560	writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT);
561	return 0;
562}
563#else
564#define s3c_rtc_suspend NULL
565#define s3c_rtc_resume  NULL
566#endif
567
568static struct platform_driver s3c2410_rtcdrv = {
569	.probe		= s3c_rtc_probe,
570	.remove		= s3c_rtc_remove,
571	.suspend	= s3c_rtc_suspend,
572	.resume		= s3c_rtc_resume,
573	.driver		= {
574		.name	= "s3c2410-rtc",
575		.owner	= THIS_MODULE,
576	},
577};
578
579static char __initdata banner[] = "S3C24XX RTC, (c) 2004,2006 Simtec Electronics\n";
580
581static int __init s3c_rtc_init(void)
582{
583	printk(banner);
584	return platform_driver_register(&s3c2410_rtcdrv);
585}
586
587static void __exit s3c_rtc_exit(void)
588{
589	platform_driver_unregister(&s3c2410_rtcdrv);
590}
591
592module_init(s3c_rtc_init);
593module_exit(s3c_rtc_exit);
594
595MODULE_DESCRIPTION("Samsung S3C RTC Driver");
596MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
597MODULE_LICENSE("GPL");
598