xref: /linux/drivers/rtc/rtc-s3c.c (revision 08ec212c0f92cbf30e3ecc7349f18151714041d6)
1 /* drivers/rtc/rtc-s3c.c
2  *
3  * Copyright (c) 2010 Samsung Electronics Co., Ltd.
4  *		http://www.samsung.com/
5  *
6  * Copyright (c) 2004,2006 Simtec Electronics
7  *	Ben Dooks, <ben@simtec.co.uk>
8  *	http://armlinux.simtec.co.uk/
9  *
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.
13  *
14  * S3C2410/S3C2440/S3C24XX Internal RTC Driver
15 */
16 
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>
28 #include <linux/of.h>
29 #include <linux/uaccess.h>
30 #include <linux/io.h>
31 
32 #include <mach/hardware.h>
33 #include <asm/irq.h>
34 #include <plat/regs-rtc.h>
35 
36 enum s3c_cpu_type {
37 	TYPE_S3C2410,
38 	TYPE_S3C2416,
39 	TYPE_S3C2443,
40 	TYPE_S3C64XX,
41 };
42 
43 struct s3c_rtc_drv_data {
44 	int cpu_type;
45 };
46 
47 /* I have yet to find an S3C implementation with more than one
48  * of these rtc blocks in */
49 
50 static struct resource *s3c_rtc_mem;
51 
52 static struct clk *rtc_clk;
53 static void __iomem *s3c_rtc_base;
54 static int s3c_rtc_alarmno = NO_IRQ;
55 static int s3c_rtc_tickno  = NO_IRQ;
56 static bool wake_en;
57 static enum s3c_cpu_type s3c_rtc_cpu_type;
58 
59 static DEFINE_SPINLOCK(s3c_rtc_pie_lock);
60 
61 static void s3c_rtc_alarm_clk_enable(bool enable)
62 {
63 	static DEFINE_SPINLOCK(s3c_rtc_alarm_clk_lock);
64 	static bool alarm_clk_enabled;
65 	unsigned long irq_flags;
66 
67 	spin_lock_irqsave(&s3c_rtc_alarm_clk_lock, irq_flags);
68 	if (enable) {
69 		if (!alarm_clk_enabled) {
70 			clk_enable(rtc_clk);
71 			alarm_clk_enabled = true;
72 		}
73 	} else {
74 		if (alarm_clk_enabled) {
75 			clk_disable(rtc_clk);
76 			alarm_clk_enabled = false;
77 		}
78 	}
79 	spin_unlock_irqrestore(&s3c_rtc_alarm_clk_lock, irq_flags);
80 }
81 
82 /* IRQ Handlers */
83 
84 static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
85 {
86 	struct rtc_device *rdev = id;
87 
88 	clk_enable(rtc_clk);
89 	rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
90 
91 	if (s3c_rtc_cpu_type == TYPE_S3C64XX)
92 		writeb(S3C2410_INTP_ALM, s3c_rtc_base + S3C2410_INTP);
93 
94 	clk_disable(rtc_clk);
95 
96 	s3c_rtc_alarm_clk_enable(false);
97 
98 	return IRQ_HANDLED;
99 }
100 
101 static irqreturn_t s3c_rtc_tickirq(int irq, void *id)
102 {
103 	struct rtc_device *rdev = id;
104 
105 	clk_enable(rtc_clk);
106 	rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF);
107 
108 	if (s3c_rtc_cpu_type == TYPE_S3C64XX)
109 		writeb(S3C2410_INTP_TIC, s3c_rtc_base + S3C2410_INTP);
110 
111 	clk_disable(rtc_clk);
112 	return IRQ_HANDLED;
113 }
114 
115 /* Update control registers */
116 static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
117 {
118 	unsigned int tmp;
119 
120 	pr_debug("%s: aie=%d\n", __func__, enabled);
121 
122 	clk_enable(rtc_clk);
123 	tmp = readb(s3c_rtc_base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
124 
125 	if (enabled)
126 		tmp |= S3C2410_RTCALM_ALMEN;
127 
128 	writeb(tmp, s3c_rtc_base + S3C2410_RTCALM);
129 	clk_disable(rtc_clk);
130 
131 	s3c_rtc_alarm_clk_enable(enabled);
132 
133 	return 0;
134 }
135 
136 static int s3c_rtc_setfreq(struct device *dev, int freq)
137 {
138 	struct platform_device *pdev = to_platform_device(dev);
139 	struct rtc_device *rtc_dev = platform_get_drvdata(pdev);
140 	unsigned int tmp = 0;
141 	int val;
142 
143 	if (!is_power_of_2(freq))
144 		return -EINVAL;
145 
146 	clk_enable(rtc_clk);
147 	spin_lock_irq(&s3c_rtc_pie_lock);
148 
149 	if (s3c_rtc_cpu_type != TYPE_S3C64XX) {
150 		tmp = readb(s3c_rtc_base + S3C2410_TICNT);
151 		tmp &= S3C2410_TICNT_ENABLE;
152 	}
153 
154 	val = (rtc_dev->max_user_freq / freq) - 1;
155 
156 	if (s3c_rtc_cpu_type == TYPE_S3C2416 || s3c_rtc_cpu_type == TYPE_S3C2443) {
157 		tmp |= S3C2443_TICNT_PART(val);
158 		writel(S3C2443_TICNT1_PART(val), s3c_rtc_base + S3C2443_TICNT1);
159 
160 		if (s3c_rtc_cpu_type == TYPE_S3C2416)
161 			writel(S3C2416_TICNT2_PART(val), s3c_rtc_base + S3C2416_TICNT2);
162 	} else {
163 		tmp |= val;
164 	}
165 
166 	writel(tmp, s3c_rtc_base + S3C2410_TICNT);
167 	spin_unlock_irq(&s3c_rtc_pie_lock);
168 	clk_disable(rtc_clk);
169 
170 	return 0;
171 }
172 
173 /* Time read/write */
174 
175 static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
176 {
177 	unsigned int have_retried = 0;
178 	void __iomem *base = s3c_rtc_base;
179 
180 	clk_enable(rtc_clk);
181  retry_get_time:
182 	rtc_tm->tm_min  = readb(base + S3C2410_RTCMIN);
183 	rtc_tm->tm_hour = readb(base + S3C2410_RTCHOUR);
184 	rtc_tm->tm_mday = readb(base + S3C2410_RTCDATE);
185 	rtc_tm->tm_mon  = readb(base + S3C2410_RTCMON);
186 	rtc_tm->tm_year = readb(base + S3C2410_RTCYEAR);
187 	rtc_tm->tm_sec  = readb(base + S3C2410_RTCSEC);
188 
189 	/* the only way to work out wether the system was mid-update
190 	 * when we read it is to check the second counter, and if it
191 	 * is zero, then we re-try the entire read
192 	 */
193 
194 	if (rtc_tm->tm_sec == 0 && !have_retried) {
195 		have_retried = 1;
196 		goto retry_get_time;
197 	}
198 
199 	rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
200 	rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
201 	rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
202 	rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
203 	rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
204 	rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
205 
206 	rtc_tm->tm_year += 100;
207 
208 	pr_debug("read time %04d.%02d.%02d %02d:%02d:%02d\n",
209 		 1900 + rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
210 		 rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
211 
212 	rtc_tm->tm_mon -= 1;
213 
214 	clk_disable(rtc_clk);
215 	return rtc_valid_tm(rtc_tm);
216 }
217 
218 static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
219 {
220 	void __iomem *base = s3c_rtc_base;
221 	int year = tm->tm_year - 100;
222 
223 	pr_debug("set time %04d.%02d.%02d %02d:%02d:%02d\n",
224 		 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
225 		 tm->tm_hour, tm->tm_min, tm->tm_sec);
226 
227 	/* we get around y2k by simply not supporting it */
228 
229 	if (year < 0 || year >= 100) {
230 		dev_err(dev, "rtc only supports 100 years\n");
231 		return -EINVAL;
232 	}
233 
234 	clk_enable(rtc_clk);
235 	writeb(bin2bcd(tm->tm_sec),  base + S3C2410_RTCSEC);
236 	writeb(bin2bcd(tm->tm_min),  base + S3C2410_RTCMIN);
237 	writeb(bin2bcd(tm->tm_hour), base + S3C2410_RTCHOUR);
238 	writeb(bin2bcd(tm->tm_mday), base + S3C2410_RTCDATE);
239 	writeb(bin2bcd(tm->tm_mon + 1), base + S3C2410_RTCMON);
240 	writeb(bin2bcd(year), base + S3C2410_RTCYEAR);
241 	clk_disable(rtc_clk);
242 
243 	return 0;
244 }
245 
246 static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
247 {
248 	struct rtc_time *alm_tm = &alrm->time;
249 	void __iomem *base = s3c_rtc_base;
250 	unsigned int alm_en;
251 
252 	clk_enable(rtc_clk);
253 	alm_tm->tm_sec  = readb(base + S3C2410_ALMSEC);
254 	alm_tm->tm_min  = readb(base + S3C2410_ALMMIN);
255 	alm_tm->tm_hour = readb(base + S3C2410_ALMHOUR);
256 	alm_tm->tm_mon  = readb(base + S3C2410_ALMMON);
257 	alm_tm->tm_mday = readb(base + S3C2410_ALMDATE);
258 	alm_tm->tm_year = readb(base + S3C2410_ALMYEAR);
259 
260 	alm_en = readb(base + S3C2410_RTCALM);
261 
262 	alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;
263 
264 	pr_debug("read alarm %d, %04d.%02d.%02d %02d:%02d:%02d\n",
265 		 alm_en,
266 		 1900 + alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
267 		 alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
268 
269 
270 	/* decode the alarm enable field */
271 
272 	if (alm_en & S3C2410_RTCALM_SECEN)
273 		alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
274 	else
275 		alm_tm->tm_sec = -1;
276 
277 	if (alm_en & S3C2410_RTCALM_MINEN)
278 		alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
279 	else
280 		alm_tm->tm_min = -1;
281 
282 	if (alm_en & S3C2410_RTCALM_HOUREN)
283 		alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
284 	else
285 		alm_tm->tm_hour = -1;
286 
287 	if (alm_en & S3C2410_RTCALM_DAYEN)
288 		alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);
289 	else
290 		alm_tm->tm_mday = -1;
291 
292 	if (alm_en & S3C2410_RTCALM_MONEN) {
293 		alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon);
294 		alm_tm->tm_mon -= 1;
295 	} else {
296 		alm_tm->tm_mon = -1;
297 	}
298 
299 	if (alm_en & S3C2410_RTCALM_YEAREN)
300 		alm_tm->tm_year = bcd2bin(alm_tm->tm_year);
301 	else
302 		alm_tm->tm_year = -1;
303 
304 	clk_disable(rtc_clk);
305 	return 0;
306 }
307 
308 static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
309 {
310 	struct rtc_time *tm = &alrm->time;
311 	void __iomem *base = s3c_rtc_base;
312 	unsigned int alrm_en;
313 
314 	clk_enable(rtc_clk);
315 	pr_debug("s3c_rtc_setalarm: %d, %04d.%02d.%02d %02d:%02d:%02d\n",
316 		 alrm->enabled,
317 		 1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
318 		 tm->tm_hour, tm->tm_min, tm->tm_sec);
319 
320 	alrm_en = readb(base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
321 	writeb(0x00, base + S3C2410_RTCALM);
322 
323 	if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
324 		alrm_en |= S3C2410_RTCALM_SECEN;
325 		writeb(bin2bcd(tm->tm_sec), base + S3C2410_ALMSEC);
326 	}
327 
328 	if (tm->tm_min < 60 && tm->tm_min >= 0) {
329 		alrm_en |= S3C2410_RTCALM_MINEN;
330 		writeb(bin2bcd(tm->tm_min), base + S3C2410_ALMMIN);
331 	}
332 
333 	if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
334 		alrm_en |= S3C2410_RTCALM_HOUREN;
335 		writeb(bin2bcd(tm->tm_hour), base + S3C2410_ALMHOUR);
336 	}
337 
338 	pr_debug("setting S3C2410_RTCALM to %08x\n", alrm_en);
339 
340 	writeb(alrm_en, base + S3C2410_RTCALM);
341 
342 	s3c_rtc_setaie(dev, alrm->enabled);
343 
344 	clk_disable(rtc_clk);
345 	return 0;
346 }
347 
348 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
349 {
350 	unsigned int ticnt;
351 
352 	clk_enable(rtc_clk);
353 	if (s3c_rtc_cpu_type == TYPE_S3C64XX) {
354 		ticnt = readw(s3c_rtc_base + S3C2410_RTCCON);
355 		ticnt &= S3C64XX_RTCCON_TICEN;
356 	} else {
357 		ticnt = readb(s3c_rtc_base + S3C2410_TICNT);
358 		ticnt &= S3C2410_TICNT_ENABLE;
359 	}
360 
361 	seq_printf(seq, "periodic_IRQ\t: %s\n", ticnt  ? "yes" : "no");
362 	clk_disable(rtc_clk);
363 	return 0;
364 }
365 
366 static const struct rtc_class_ops s3c_rtcops = {
367 	.read_time	= s3c_rtc_gettime,
368 	.set_time	= s3c_rtc_settime,
369 	.read_alarm	= s3c_rtc_getalarm,
370 	.set_alarm	= s3c_rtc_setalarm,
371 	.proc		= s3c_rtc_proc,
372 	.alarm_irq_enable = s3c_rtc_setaie,
373 };
374 
375 static void s3c_rtc_enable(struct platform_device *pdev, int en)
376 {
377 	void __iomem *base = s3c_rtc_base;
378 	unsigned int tmp;
379 
380 	if (s3c_rtc_base == NULL)
381 		return;
382 
383 	clk_enable(rtc_clk);
384 	if (!en) {
385 		tmp = readw(base + S3C2410_RTCCON);
386 		if (s3c_rtc_cpu_type == TYPE_S3C64XX)
387 			tmp &= ~S3C64XX_RTCCON_TICEN;
388 		tmp &= ~S3C2410_RTCCON_RTCEN;
389 		writew(tmp, base + S3C2410_RTCCON);
390 
391 		if (s3c_rtc_cpu_type != TYPE_S3C64XX) {
392 			tmp = readb(base + S3C2410_TICNT);
393 			tmp &= ~S3C2410_TICNT_ENABLE;
394 			writeb(tmp, base + S3C2410_TICNT);
395 		}
396 	} else {
397 		/* re-enable the device, and check it is ok */
398 
399 		if ((readw(base+S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0) {
400 			dev_info(&pdev->dev, "rtc disabled, re-enabling\n");
401 
402 			tmp = readw(base + S3C2410_RTCCON);
403 			writew(tmp | S3C2410_RTCCON_RTCEN,
404 				base + S3C2410_RTCCON);
405 		}
406 
407 		if ((readw(base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)) {
408 			dev_info(&pdev->dev, "removing RTCCON_CNTSEL\n");
409 
410 			tmp = readw(base + S3C2410_RTCCON);
411 			writew(tmp & ~S3C2410_RTCCON_CNTSEL,
412 				base + S3C2410_RTCCON);
413 		}
414 
415 		if ((readw(base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)) {
416 			dev_info(&pdev->dev, "removing RTCCON_CLKRST\n");
417 
418 			tmp = readw(base + S3C2410_RTCCON);
419 			writew(tmp & ~S3C2410_RTCCON_CLKRST,
420 				base + S3C2410_RTCCON);
421 		}
422 	}
423 	clk_disable(rtc_clk);
424 }
425 
426 static int __devexit s3c_rtc_remove(struct platform_device *dev)
427 {
428 	struct rtc_device *rtc = platform_get_drvdata(dev);
429 
430 	free_irq(s3c_rtc_alarmno, rtc);
431 	free_irq(s3c_rtc_tickno, rtc);
432 
433 	platform_set_drvdata(dev, NULL);
434 	rtc_device_unregister(rtc);
435 
436 	s3c_rtc_setaie(&dev->dev, 0);
437 
438 	clk_put(rtc_clk);
439 	rtc_clk = NULL;
440 
441 	iounmap(s3c_rtc_base);
442 	release_resource(s3c_rtc_mem);
443 	kfree(s3c_rtc_mem);
444 
445 	return 0;
446 }
447 
448 static const struct of_device_id s3c_rtc_dt_match[];
449 
450 static inline int s3c_rtc_get_driver_data(struct platform_device *pdev)
451 {
452 #ifdef CONFIG_OF
453 	struct s3c_rtc_drv_data *data;
454 	if (pdev->dev.of_node) {
455 		const struct of_device_id *match;
456 		match = of_match_node(s3c_rtc_dt_match, pdev->dev.of_node);
457 		data = (struct s3c_rtc_drv_data *) match->data;
458 		return data->cpu_type;
459 	}
460 #endif
461 	return platform_get_device_id(pdev)->driver_data;
462 }
463 
464 static int __devinit s3c_rtc_probe(struct platform_device *pdev)
465 {
466 	struct rtc_device *rtc;
467 	struct rtc_time rtc_tm;
468 	struct resource *res;
469 	int ret;
470 	int tmp;
471 
472 	pr_debug("%s: probe=%p\n", __func__, pdev);
473 
474 	/* find the IRQs */
475 
476 	s3c_rtc_tickno = platform_get_irq(pdev, 1);
477 	if (s3c_rtc_tickno < 0) {
478 		dev_err(&pdev->dev, "no irq for rtc tick\n");
479 		return s3c_rtc_tickno;
480 	}
481 
482 	s3c_rtc_alarmno = platform_get_irq(pdev, 0);
483 	if (s3c_rtc_alarmno < 0) {
484 		dev_err(&pdev->dev, "no irq for alarm\n");
485 		return s3c_rtc_alarmno;
486 	}
487 
488 	pr_debug("s3c2410_rtc: tick irq %d, alarm irq %d\n",
489 		 s3c_rtc_tickno, s3c_rtc_alarmno);
490 
491 	/* get the memory region */
492 
493 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
494 	if (res == NULL) {
495 		dev_err(&pdev->dev, "failed to get memory region resource\n");
496 		return -ENOENT;
497 	}
498 
499 	s3c_rtc_mem = request_mem_region(res->start, resource_size(res),
500 					 pdev->name);
501 
502 	if (s3c_rtc_mem == NULL) {
503 		dev_err(&pdev->dev, "failed to reserve memory region\n");
504 		ret = -ENOENT;
505 		goto err_nores;
506 	}
507 
508 	s3c_rtc_base = ioremap(res->start, resource_size(res));
509 	if (s3c_rtc_base == NULL) {
510 		dev_err(&pdev->dev, "failed ioremap()\n");
511 		ret = -EINVAL;
512 		goto err_nomap;
513 	}
514 
515 	rtc_clk = clk_get(&pdev->dev, "rtc");
516 	if (IS_ERR(rtc_clk)) {
517 		dev_err(&pdev->dev, "failed to find rtc clock source\n");
518 		ret = PTR_ERR(rtc_clk);
519 		rtc_clk = NULL;
520 		goto err_clk;
521 	}
522 
523 	clk_enable(rtc_clk);
524 
525 	/* check to see if everything is setup correctly */
526 
527 	s3c_rtc_enable(pdev, 1);
528 
529 	pr_debug("s3c2410_rtc: RTCCON=%02x\n",
530 		 readw(s3c_rtc_base + S3C2410_RTCCON));
531 
532 	device_init_wakeup(&pdev->dev, 1);
533 
534 	/* register RTC and exit */
535 
536 	rtc = rtc_device_register("s3c", &pdev->dev, &s3c_rtcops,
537 				  THIS_MODULE);
538 
539 	if (IS_ERR(rtc)) {
540 		dev_err(&pdev->dev, "cannot attach rtc\n");
541 		ret = PTR_ERR(rtc);
542 		goto err_nortc;
543 	}
544 
545 	s3c_rtc_cpu_type = s3c_rtc_get_driver_data(pdev);
546 
547 	/* Check RTC Time */
548 
549 	s3c_rtc_gettime(NULL, &rtc_tm);
550 
551 	if (rtc_valid_tm(&rtc_tm)) {
552 		rtc_tm.tm_year	= 100;
553 		rtc_tm.tm_mon	= 0;
554 		rtc_tm.tm_mday	= 1;
555 		rtc_tm.tm_hour	= 0;
556 		rtc_tm.tm_min	= 0;
557 		rtc_tm.tm_sec	= 0;
558 
559 		s3c_rtc_settime(NULL, &rtc_tm);
560 
561 		dev_warn(&pdev->dev, "warning: invalid RTC value so initializing it\n");
562 	}
563 
564 	if (s3c_rtc_cpu_type != TYPE_S3C2410)
565 		rtc->max_user_freq = 32768;
566 	else
567 		rtc->max_user_freq = 128;
568 
569 	if (s3c_rtc_cpu_type == TYPE_S3C2416 || s3c_rtc_cpu_type == TYPE_S3C2443) {
570 		tmp = readw(s3c_rtc_base + S3C2410_RTCCON);
571 		tmp |= S3C2443_RTCCON_TICSEL;
572 		writew(tmp, s3c_rtc_base + S3C2410_RTCCON);
573 	}
574 
575 	platform_set_drvdata(pdev, rtc);
576 
577 	s3c_rtc_setfreq(&pdev->dev, 1);
578 
579 	ret = request_irq(s3c_rtc_alarmno, s3c_rtc_alarmirq,
580 			  0,  "s3c2410-rtc alarm", rtc);
581 	if (ret) {
582 		dev_err(&pdev->dev, "IRQ%d error %d\n", s3c_rtc_alarmno, ret);
583 		goto err_alarm_irq;
584 	}
585 
586 	ret = request_irq(s3c_rtc_tickno, s3c_rtc_tickirq,
587 			  0,  "s3c2410-rtc tick", rtc);
588 	if (ret) {
589 		dev_err(&pdev->dev, "IRQ%d error %d\n", s3c_rtc_tickno, ret);
590 		free_irq(s3c_rtc_alarmno, rtc);
591 		goto err_tick_irq;
592 	}
593 
594 	clk_disable(rtc_clk);
595 
596 	return 0;
597 
598  err_tick_irq:
599 	free_irq(s3c_rtc_alarmno, rtc);
600 
601  err_alarm_irq:
602 	platform_set_drvdata(pdev, NULL);
603 	rtc_device_unregister(rtc);
604 
605  err_nortc:
606 	s3c_rtc_enable(pdev, 0);
607 	clk_disable(rtc_clk);
608 	clk_put(rtc_clk);
609 
610  err_clk:
611 	iounmap(s3c_rtc_base);
612 
613  err_nomap:
614 	release_resource(s3c_rtc_mem);
615 
616  err_nores:
617 	return ret;
618 }
619 
620 #ifdef CONFIG_PM
621 
622 /* RTC Power management control */
623 
624 static int ticnt_save, ticnt_en_save;
625 
626 static int s3c_rtc_suspend(struct platform_device *pdev, pm_message_t state)
627 {
628 	clk_enable(rtc_clk);
629 	/* save TICNT for anyone using periodic interrupts */
630 	ticnt_save = readb(s3c_rtc_base + S3C2410_TICNT);
631 	if (s3c_rtc_cpu_type == TYPE_S3C64XX) {
632 		ticnt_en_save = readw(s3c_rtc_base + S3C2410_RTCCON);
633 		ticnt_en_save &= S3C64XX_RTCCON_TICEN;
634 	}
635 	s3c_rtc_enable(pdev, 0);
636 
637 	if (device_may_wakeup(&pdev->dev) && !wake_en) {
638 		if (enable_irq_wake(s3c_rtc_alarmno) == 0)
639 			wake_en = true;
640 		else
641 			dev_err(&pdev->dev, "enable_irq_wake failed\n");
642 	}
643 	clk_disable(rtc_clk);
644 
645 	return 0;
646 }
647 
648 static int s3c_rtc_resume(struct platform_device *pdev)
649 {
650 	unsigned int tmp;
651 
652 	clk_enable(rtc_clk);
653 	s3c_rtc_enable(pdev, 1);
654 	writeb(ticnt_save, s3c_rtc_base + S3C2410_TICNT);
655 	if (s3c_rtc_cpu_type == TYPE_S3C64XX && ticnt_en_save) {
656 		tmp = readw(s3c_rtc_base + S3C2410_RTCCON);
657 		writew(tmp | ticnt_en_save, s3c_rtc_base + S3C2410_RTCCON);
658 	}
659 
660 	if (device_may_wakeup(&pdev->dev) && wake_en) {
661 		disable_irq_wake(s3c_rtc_alarmno);
662 		wake_en = false;
663 	}
664 	clk_disable(rtc_clk);
665 
666 	return 0;
667 }
668 #else
669 #define s3c_rtc_suspend NULL
670 #define s3c_rtc_resume  NULL
671 #endif
672 
673 #ifdef CONFIG_OF
674 static struct s3c_rtc_drv_data s3c_rtc_drv_data_array[] = {
675 	[TYPE_S3C2410] = { TYPE_S3C2410 },
676 	[TYPE_S3C2416] = { TYPE_S3C2416 },
677 	[TYPE_S3C2443] = { TYPE_S3C2443 },
678 	[TYPE_S3C64XX] = { TYPE_S3C64XX },
679 };
680 
681 static const struct of_device_id s3c_rtc_dt_match[] = {
682 	{
683 		.compatible = "samsung,s3c2410-rtc",
684 		.data = &s3c_rtc_drv_data_array[TYPE_S3C2410],
685 	}, {
686 		.compatible = "samsung,s3c2416-rtc",
687 		.data = &s3c_rtc_drv_data_array[TYPE_S3C2416],
688 	}, {
689 		.compatible = "samsung,s3c2443-rtc",
690 		.data = &s3c_rtc_drv_data_array[TYPE_S3C2443],
691 	}, {
692 		.compatible = "samsung,s3c6410-rtc",
693 		.data = &s3c_rtc_drv_data_array[TYPE_S3C64XX],
694 	},
695 	{},
696 };
697 MODULE_DEVICE_TABLE(of, s3c_rtc_dt_match);
698 #else
699 #define s3c_rtc_dt_match NULL
700 #endif
701 
702 static struct platform_device_id s3c_rtc_driver_ids[] = {
703 	{
704 		.name		= "s3c2410-rtc",
705 		.driver_data	= TYPE_S3C2410,
706 	}, {
707 		.name		= "s3c2416-rtc",
708 		.driver_data	= TYPE_S3C2416,
709 	}, {
710 		.name		= "s3c2443-rtc",
711 		.driver_data	= TYPE_S3C2443,
712 	}, {
713 		.name		= "s3c64xx-rtc",
714 		.driver_data	= TYPE_S3C64XX,
715 	},
716 	{ }
717 };
718 
719 MODULE_DEVICE_TABLE(platform, s3c_rtc_driver_ids);
720 
721 static struct platform_driver s3c_rtc_driver = {
722 	.probe		= s3c_rtc_probe,
723 	.remove		= __devexit_p(s3c_rtc_remove),
724 	.suspend	= s3c_rtc_suspend,
725 	.resume		= s3c_rtc_resume,
726 	.id_table	= s3c_rtc_driver_ids,
727 	.driver		= {
728 		.name	= "s3c-rtc",
729 		.owner	= THIS_MODULE,
730 		.of_match_table	= s3c_rtc_dt_match,
731 	},
732 };
733 
734 module_platform_driver(s3c_rtc_driver);
735 
736 MODULE_DESCRIPTION("Samsung S3C RTC Driver");
737 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
738 MODULE_LICENSE("GPL");
739 MODULE_ALIAS("platform:s3c2410-rtc");
740