xref: /openbmc/linux/drivers/rtc/rtc-s3c.c (revision d3964221)
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 <asm/irq.h>
33 #include "rtc-s3c.h"
34 
35 struct s3c_rtc {
36 	struct device *dev;
37 	struct rtc_device *rtc;
38 
39 	void __iomem *base;
40 	struct clk *rtc_clk;
41 	struct clk *rtc_src_clk;
42 	bool clk_disabled;
43 
44 	const struct s3c_rtc_data *data;
45 
46 	int irq_alarm;
47 	int irq_tick;
48 
49 	spinlock_t pie_lock;
50 	spinlock_t alarm_clk_lock;
51 
52 	int ticnt_save;
53 	int ticnt_en_save;
54 	bool wake_en;
55 };
56 
57 struct s3c_rtc_data {
58 	int max_user_freq;
59 	bool needs_src_clk;
60 
61 	void (*irq_handler) (struct s3c_rtc *info, int mask);
62 	void (*set_freq) (struct s3c_rtc *info, int freq);
63 	void (*enable_tick) (struct s3c_rtc *info, struct seq_file *seq);
64 	void (*select_tick_clk) (struct s3c_rtc *info);
65 	void (*save_tick_cnt) (struct s3c_rtc *info);
66 	void (*restore_tick_cnt) (struct s3c_rtc *info);
67 	void (*enable) (struct s3c_rtc *info);
68 	void (*disable) (struct s3c_rtc *info);
69 };
70 
71 static int s3c_rtc_enable_clk(struct s3c_rtc *info)
72 {
73 	unsigned long irq_flags;
74 	int ret = 0;
75 
76 	spin_lock_irqsave(&info->alarm_clk_lock, irq_flags);
77 
78 	if (info->clk_disabled) {
79 		ret = clk_enable(info->rtc_clk);
80 		if (ret)
81 			goto out;
82 
83 		if (info->data->needs_src_clk) {
84 			ret = clk_enable(info->rtc_src_clk);
85 			if (ret) {
86 				clk_disable(info->rtc_clk);
87 				goto out;
88 			}
89 		}
90 		info->clk_disabled = false;
91 	}
92 
93 out:
94 	spin_unlock_irqrestore(&info->alarm_clk_lock, irq_flags);
95 
96 	return ret;
97 }
98 
99 static void s3c_rtc_disable_clk(struct s3c_rtc *info)
100 {
101 	unsigned long irq_flags;
102 
103 	spin_lock_irqsave(&info->alarm_clk_lock, irq_flags);
104 	if (!info->clk_disabled) {
105 		if (info->data->needs_src_clk)
106 			clk_disable(info->rtc_src_clk);
107 		clk_disable(info->rtc_clk);
108 		info->clk_disabled = true;
109 	}
110 	spin_unlock_irqrestore(&info->alarm_clk_lock, irq_flags);
111 }
112 
113 /* IRQ Handlers */
114 static irqreturn_t s3c_rtc_tickirq(int irq, void *id)
115 {
116 	struct s3c_rtc *info = (struct s3c_rtc *)id;
117 
118 	if (info->data->irq_handler)
119 		info->data->irq_handler(info, S3C2410_INTP_TIC);
120 
121 	return IRQ_HANDLED;
122 }
123 
124 static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
125 {
126 	struct s3c_rtc *info = (struct s3c_rtc *)id;
127 
128 	if (info->data->irq_handler)
129 		info->data->irq_handler(info, S3C2410_INTP_ALM);
130 
131 	return IRQ_HANDLED;
132 }
133 
134 /* Update control registers */
135 static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
136 {
137 	struct s3c_rtc *info = dev_get_drvdata(dev);
138 	unsigned int tmp;
139 	int ret;
140 
141 	dev_dbg(info->dev, "%s: aie=%d\n", __func__, enabled);
142 
143 	ret = s3c_rtc_enable_clk(info);
144 	if (ret)
145 		return ret;
146 
147 	tmp = readb(info->base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
148 
149 	if (enabled)
150 		tmp |= S3C2410_RTCALM_ALMEN;
151 
152 	writeb(tmp, info->base + S3C2410_RTCALM);
153 
154 	s3c_rtc_disable_clk(info);
155 
156 	if (enabled) {
157 		ret = s3c_rtc_enable_clk(info);
158 		if (ret)
159 			return ret;
160 	} else {
161 		s3c_rtc_disable_clk(info);
162 	}
163 
164 	return 0;
165 }
166 
167 /* Set RTC frequency */
168 static int s3c_rtc_setfreq(struct s3c_rtc *info, int freq)
169 {
170 	int ret;
171 
172 	if (!is_power_of_2(freq))
173 		return -EINVAL;
174 
175 	ret = s3c_rtc_enable_clk(info);
176 	if (ret)
177 		return ret;
178 	spin_lock_irq(&info->pie_lock);
179 
180 	if (info->data->set_freq)
181 		info->data->set_freq(info, freq);
182 
183 	spin_unlock_irq(&info->pie_lock);
184 	s3c_rtc_disable_clk(info);
185 
186 	return 0;
187 }
188 
189 /* Time read/write */
190 static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
191 {
192 	struct s3c_rtc *info = dev_get_drvdata(dev);
193 	unsigned int have_retried = 0;
194 	int ret;
195 
196 	ret = s3c_rtc_enable_clk(info);
197 	if (ret)
198 		return ret;
199 
200 retry_get_time:
201 	rtc_tm->tm_min  = readb(info->base + S3C2410_RTCMIN);
202 	rtc_tm->tm_hour = readb(info->base + S3C2410_RTCHOUR);
203 	rtc_tm->tm_mday = readb(info->base + S3C2410_RTCDATE);
204 	rtc_tm->tm_mon  = readb(info->base + S3C2410_RTCMON);
205 	rtc_tm->tm_year = readb(info->base + S3C2410_RTCYEAR);
206 	rtc_tm->tm_sec  = readb(info->base + S3C2410_RTCSEC);
207 
208 	/* the only way to work out whether the system was mid-update
209 	 * when we read it is to check the second counter, and if it
210 	 * is zero, then we re-try the entire read
211 	 */
212 
213 	if (rtc_tm->tm_sec == 0 && !have_retried) {
214 		have_retried = 1;
215 		goto retry_get_time;
216 	}
217 
218 	rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
219 	rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
220 	rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
221 	rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
222 	rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
223 	rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
224 
225 	s3c_rtc_disable_clk(info);
226 
227 	rtc_tm->tm_year += 100;
228 
229 	dev_dbg(dev, "read time %04d.%02d.%02d %02d:%02d:%02d\n",
230 		1900 + rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
231 		rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
232 
233 	rtc_tm->tm_mon -= 1;
234 
235 	return rtc_valid_tm(rtc_tm);
236 }
237 
238 static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
239 {
240 	struct s3c_rtc *info = dev_get_drvdata(dev);
241 	int year = tm->tm_year - 100;
242 	int ret;
243 
244 	dev_dbg(dev, "set time %04d.%02d.%02d %02d:%02d:%02d\n",
245 		1900 + tm->tm_year, tm->tm_mon, tm->tm_mday,
246 		tm->tm_hour, tm->tm_min, tm->tm_sec);
247 
248 	/* we get around y2k by simply not supporting it */
249 
250 	if (year < 0 || year >= 100) {
251 		dev_err(dev, "rtc only supports 100 years\n");
252 		return -EINVAL;
253 	}
254 
255 	ret = s3c_rtc_enable_clk(info);
256 	if (ret)
257 		return ret;
258 
259 	writeb(bin2bcd(tm->tm_sec),  info->base + S3C2410_RTCSEC);
260 	writeb(bin2bcd(tm->tm_min),  info->base + S3C2410_RTCMIN);
261 	writeb(bin2bcd(tm->tm_hour), info->base + S3C2410_RTCHOUR);
262 	writeb(bin2bcd(tm->tm_mday), info->base + S3C2410_RTCDATE);
263 	writeb(bin2bcd(tm->tm_mon + 1), info->base + S3C2410_RTCMON);
264 	writeb(bin2bcd(year), info->base + S3C2410_RTCYEAR);
265 
266 	s3c_rtc_disable_clk(info);
267 
268 	return 0;
269 }
270 
271 static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
272 {
273 	struct s3c_rtc *info = dev_get_drvdata(dev);
274 	struct rtc_time *alm_tm = &alrm->time;
275 	unsigned int alm_en;
276 	int ret;
277 
278 	ret = s3c_rtc_enable_clk(info);
279 	if (ret)
280 		return ret;
281 
282 	alm_tm->tm_sec  = readb(info->base + S3C2410_ALMSEC);
283 	alm_tm->tm_min  = readb(info->base + S3C2410_ALMMIN);
284 	alm_tm->tm_hour = readb(info->base + S3C2410_ALMHOUR);
285 	alm_tm->tm_mon  = readb(info->base + S3C2410_ALMMON);
286 	alm_tm->tm_mday = readb(info->base + S3C2410_ALMDATE);
287 	alm_tm->tm_year = readb(info->base + S3C2410_ALMYEAR);
288 
289 	alm_en = readb(info->base + S3C2410_RTCALM);
290 
291 	s3c_rtc_disable_clk(info);
292 
293 	alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;
294 
295 	dev_dbg(dev, "read alarm %d, %04d.%02d.%02d %02d:%02d:%02d\n",
296 		alm_en,
297 		1900 + alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
298 		alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
299 
300 	/* decode the alarm enable field */
301 	if (alm_en & S3C2410_RTCALM_SECEN)
302 		alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
303 
304 	if (alm_en & S3C2410_RTCALM_MINEN)
305 		alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
306 
307 	if (alm_en & S3C2410_RTCALM_HOUREN)
308 		alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
309 
310 	if (alm_en & S3C2410_RTCALM_DAYEN)
311 		alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);
312 
313 	if (alm_en & S3C2410_RTCALM_MONEN) {
314 		alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon);
315 		alm_tm->tm_mon -= 1;
316 	}
317 
318 	if (alm_en & S3C2410_RTCALM_YEAREN)
319 		alm_tm->tm_year = bcd2bin(alm_tm->tm_year);
320 
321 	return 0;
322 }
323 
324 static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
325 {
326 	struct s3c_rtc *info = dev_get_drvdata(dev);
327 	struct rtc_time *tm = &alrm->time;
328 	unsigned int alrm_en;
329 	int ret;
330 	int year = tm->tm_year - 100;
331 
332 	dev_dbg(dev, "s3c_rtc_setalarm: %d, %04d.%02d.%02d %02d:%02d:%02d\n",
333 		alrm->enabled,
334 		1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
335 		tm->tm_hour, tm->tm_min, tm->tm_sec);
336 
337 	ret = s3c_rtc_enable_clk(info);
338 	if (ret)
339 		return ret;
340 
341 	alrm_en = readb(info->base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
342 	writeb(0x00, info->base + S3C2410_RTCALM);
343 
344 	if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
345 		alrm_en |= S3C2410_RTCALM_SECEN;
346 		writeb(bin2bcd(tm->tm_sec), info->base + S3C2410_ALMSEC);
347 	}
348 
349 	if (tm->tm_min < 60 && tm->tm_min >= 0) {
350 		alrm_en |= S3C2410_RTCALM_MINEN;
351 		writeb(bin2bcd(tm->tm_min), info->base + S3C2410_ALMMIN);
352 	}
353 
354 	if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
355 		alrm_en |= S3C2410_RTCALM_HOUREN;
356 		writeb(bin2bcd(tm->tm_hour), info->base + S3C2410_ALMHOUR);
357 	}
358 
359 	if (year < 100 && year >= 0) {
360 		alrm_en |= S3C2410_RTCALM_YEAREN;
361 		writeb(bin2bcd(year), info->base + S3C2410_ALMYEAR);
362 	}
363 
364 	if (tm->tm_mon < 12 && tm->tm_mon >= 0) {
365 		alrm_en |= S3C2410_RTCALM_MONEN;
366 		writeb(bin2bcd(tm->tm_mon + 1), info->base + S3C2410_ALMMON);
367 	}
368 
369 	if (tm->tm_mday <= 31 && tm->tm_mday >= 1) {
370 		alrm_en |= S3C2410_RTCALM_DAYEN;
371 		writeb(bin2bcd(tm->tm_mday), info->base + S3C2410_ALMDATE);
372 	}
373 
374 	dev_dbg(dev, "setting S3C2410_RTCALM to %08x\n", alrm_en);
375 
376 	writeb(alrm_en, info->base + S3C2410_RTCALM);
377 
378 	s3c_rtc_disable_clk(info);
379 
380 	s3c_rtc_setaie(dev, alrm->enabled);
381 
382 	return 0;
383 }
384 
385 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
386 {
387 	struct s3c_rtc *info = dev_get_drvdata(dev);
388 	int ret;
389 
390 	ret = s3c_rtc_enable_clk(info);
391 	if (ret)
392 		return ret;
393 
394 	if (info->data->enable_tick)
395 		info->data->enable_tick(info, seq);
396 
397 	s3c_rtc_disable_clk(info);
398 
399 	return 0;
400 }
401 
402 static const struct rtc_class_ops s3c_rtcops = {
403 	.read_time	= s3c_rtc_gettime,
404 	.set_time	= s3c_rtc_settime,
405 	.read_alarm	= s3c_rtc_getalarm,
406 	.set_alarm	= s3c_rtc_setalarm,
407 	.proc		= s3c_rtc_proc,
408 	.alarm_irq_enable = s3c_rtc_setaie,
409 };
410 
411 static void s3c24xx_rtc_enable(struct s3c_rtc *info)
412 {
413 	unsigned int con, tmp;
414 
415 	con = readw(info->base + S3C2410_RTCCON);
416 	/* re-enable the device, and check it is ok */
417 	if ((con & S3C2410_RTCCON_RTCEN) == 0) {
418 		dev_info(info->dev, "rtc disabled, re-enabling\n");
419 
420 		tmp = readw(info->base + S3C2410_RTCCON);
421 		writew(tmp | S3C2410_RTCCON_RTCEN, info->base + S3C2410_RTCCON);
422 	}
423 
424 	if (con & S3C2410_RTCCON_CNTSEL) {
425 		dev_info(info->dev, "removing RTCCON_CNTSEL\n");
426 
427 		tmp = readw(info->base + S3C2410_RTCCON);
428 		writew(tmp & ~S3C2410_RTCCON_CNTSEL,
429 		       info->base + S3C2410_RTCCON);
430 	}
431 
432 	if (con & S3C2410_RTCCON_CLKRST) {
433 		dev_info(info->dev, "removing RTCCON_CLKRST\n");
434 
435 		tmp = readw(info->base + S3C2410_RTCCON);
436 		writew(tmp & ~S3C2410_RTCCON_CLKRST,
437 		       info->base + S3C2410_RTCCON);
438 	}
439 }
440 
441 static void s3c24xx_rtc_disable(struct s3c_rtc *info)
442 {
443 	unsigned int con;
444 
445 	con = readw(info->base + S3C2410_RTCCON);
446 	con &= ~S3C2410_RTCCON_RTCEN;
447 	writew(con, info->base + S3C2410_RTCCON);
448 
449 	con = readb(info->base + S3C2410_TICNT);
450 	con &= ~S3C2410_TICNT_ENABLE;
451 	writeb(con, info->base + S3C2410_TICNT);
452 }
453 
454 static void s3c6410_rtc_disable(struct s3c_rtc *info)
455 {
456 	unsigned int con;
457 
458 	con = readw(info->base + S3C2410_RTCCON);
459 	con &= ~S3C64XX_RTCCON_TICEN;
460 	con &= ~S3C2410_RTCCON_RTCEN;
461 	writew(con, info->base + S3C2410_RTCCON);
462 }
463 
464 static int s3c_rtc_remove(struct platform_device *pdev)
465 {
466 	struct s3c_rtc *info = platform_get_drvdata(pdev);
467 
468 	s3c_rtc_setaie(info->dev, 0);
469 
470 	if (info->data->needs_src_clk)
471 		clk_unprepare(info->rtc_src_clk);
472 	clk_unprepare(info->rtc_clk);
473 
474 	return 0;
475 }
476 
477 static const struct of_device_id s3c_rtc_dt_match[];
478 
479 static const struct s3c_rtc_data *s3c_rtc_get_data(struct platform_device *pdev)
480 {
481 	const struct of_device_id *match;
482 
483 	match = of_match_node(s3c_rtc_dt_match, pdev->dev.of_node);
484 	return match->data;
485 }
486 
487 static int s3c_rtc_probe(struct platform_device *pdev)
488 {
489 	struct s3c_rtc *info = NULL;
490 	struct rtc_time rtc_tm;
491 	struct resource *res;
492 	int ret;
493 
494 	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
495 	if (!info)
496 		return -ENOMEM;
497 
498 	/* find the IRQs */
499 	info->irq_tick = platform_get_irq(pdev, 1);
500 	if (info->irq_tick < 0) {
501 		dev_err(&pdev->dev, "no irq for rtc tick\n");
502 		return info->irq_tick;
503 	}
504 
505 	info->dev = &pdev->dev;
506 	info->data = s3c_rtc_get_data(pdev);
507 	if (!info->data) {
508 		dev_err(&pdev->dev, "failed getting s3c_rtc_data\n");
509 		return -EINVAL;
510 	}
511 	spin_lock_init(&info->pie_lock);
512 	spin_lock_init(&info->alarm_clk_lock);
513 
514 	platform_set_drvdata(pdev, info);
515 
516 	info->irq_alarm = platform_get_irq(pdev, 0);
517 	if (info->irq_alarm < 0) {
518 		dev_err(&pdev->dev, "no irq for alarm\n");
519 		return info->irq_alarm;
520 	}
521 
522 	dev_dbg(&pdev->dev, "s3c2410_rtc: tick irq %d, alarm irq %d\n",
523 		info->irq_tick, info->irq_alarm);
524 
525 	/* get the memory region */
526 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
527 	info->base = devm_ioremap_resource(&pdev->dev, res);
528 	if (IS_ERR(info->base))
529 		return PTR_ERR(info->base);
530 
531 	info->rtc_clk = devm_clk_get(&pdev->dev, "rtc");
532 	if (IS_ERR(info->rtc_clk)) {
533 		ret = PTR_ERR(info->rtc_clk);
534 		if (ret != -EPROBE_DEFER)
535 			dev_err(&pdev->dev, "failed to find rtc clock\n");
536 		else
537 			dev_dbg(&pdev->dev, "probe deferred due to missing rtc clk\n");
538 		return ret;
539 	}
540 	ret = clk_prepare_enable(info->rtc_clk);
541 	if (ret)
542 		return ret;
543 
544 	if (info->data->needs_src_clk) {
545 		info->rtc_src_clk = devm_clk_get(&pdev->dev, "rtc_src");
546 		if (IS_ERR(info->rtc_src_clk)) {
547 			ret = PTR_ERR(info->rtc_src_clk);
548 			if (ret != -EPROBE_DEFER)
549 				dev_err(&pdev->dev,
550 					"failed to find rtc source clock\n");
551 			else
552 				dev_dbg(&pdev->dev,
553 					"probe deferred due to missing rtc src clk\n");
554 			goto err_src_clk;
555 		}
556 		ret = clk_prepare_enable(info->rtc_src_clk);
557 		if (ret)
558 			goto err_src_clk;
559 	}
560 
561 	/* check to see if everything is setup correctly */
562 	if (info->data->enable)
563 		info->data->enable(info);
564 
565 	dev_dbg(&pdev->dev, "s3c2410_rtc: RTCCON=%02x\n",
566 		readw(info->base + S3C2410_RTCCON));
567 
568 	device_init_wakeup(&pdev->dev, 1);
569 
570 	/* Check RTC Time */
571 	if (s3c_rtc_gettime(&pdev->dev, &rtc_tm)) {
572 		rtc_tm.tm_year	= 100;
573 		rtc_tm.tm_mon	= 0;
574 		rtc_tm.tm_mday	= 1;
575 		rtc_tm.tm_hour	= 0;
576 		rtc_tm.tm_min	= 0;
577 		rtc_tm.tm_sec	= 0;
578 
579 		s3c_rtc_settime(&pdev->dev, &rtc_tm);
580 
581 		dev_warn(&pdev->dev, "warning: invalid RTC value so initializing it\n");
582 	}
583 
584 	/* register RTC and exit */
585 	info->rtc = devm_rtc_device_register(&pdev->dev, "s3c", &s3c_rtcops,
586 					     THIS_MODULE);
587 	if (IS_ERR(info->rtc)) {
588 		dev_err(&pdev->dev, "cannot attach rtc\n");
589 		ret = PTR_ERR(info->rtc);
590 		goto err_nortc;
591 	}
592 
593 	ret = devm_request_irq(&pdev->dev, info->irq_alarm, s3c_rtc_alarmirq,
594 			       0, "s3c2410-rtc alarm", info);
595 	if (ret) {
596 		dev_err(&pdev->dev, "IRQ%d error %d\n", info->irq_alarm, ret);
597 		goto err_nortc;
598 	}
599 
600 	ret = devm_request_irq(&pdev->dev, info->irq_tick, s3c_rtc_tickirq,
601 			       0, "s3c2410-rtc tick", info);
602 	if (ret) {
603 		dev_err(&pdev->dev, "IRQ%d error %d\n", info->irq_tick, ret);
604 		goto err_nortc;
605 	}
606 
607 	if (info->data->select_tick_clk)
608 		info->data->select_tick_clk(info);
609 
610 	s3c_rtc_setfreq(info, 1);
611 
612 	return 0;
613 
614 err_nortc:
615 	if (info->data->disable)
616 		info->data->disable(info);
617 
618 	if (info->data->needs_src_clk)
619 		clk_disable_unprepare(info->rtc_src_clk);
620 err_src_clk:
621 	clk_disable_unprepare(info->rtc_clk);
622 
623 	return ret;
624 }
625 
626 #ifdef CONFIG_PM_SLEEP
627 
628 static int s3c_rtc_suspend(struct device *dev)
629 {
630 	struct s3c_rtc *info = dev_get_drvdata(dev);
631 	int ret;
632 
633 	ret = s3c_rtc_enable_clk(info);
634 	if (ret)
635 		return ret;
636 
637 	/* save TICNT for anyone using periodic interrupts */
638 	if (info->data->save_tick_cnt)
639 		info->data->save_tick_cnt(info);
640 
641 	if (info->data->disable)
642 		info->data->disable(info);
643 
644 	if (device_may_wakeup(dev) && !info->wake_en) {
645 		if (enable_irq_wake(info->irq_alarm) == 0)
646 			info->wake_en = true;
647 		else
648 			dev_err(dev, "enable_irq_wake failed\n");
649 	}
650 
651 	return 0;
652 }
653 
654 static int s3c_rtc_resume(struct device *dev)
655 {
656 	struct s3c_rtc *info = dev_get_drvdata(dev);
657 
658 	if (info->data->enable)
659 		info->data->enable(info);
660 
661 	if (info->data->restore_tick_cnt)
662 		info->data->restore_tick_cnt(info);
663 
664 	s3c_rtc_disable_clk(info);
665 
666 	if (device_may_wakeup(dev) && info->wake_en) {
667 		disable_irq_wake(info->irq_alarm);
668 		info->wake_en = false;
669 	}
670 
671 	return 0;
672 }
673 #endif
674 static SIMPLE_DEV_PM_OPS(s3c_rtc_pm_ops, s3c_rtc_suspend, s3c_rtc_resume);
675 
676 static void s3c24xx_rtc_irq(struct s3c_rtc *info, int mask)
677 {
678 	rtc_update_irq(info->rtc, 1, RTC_AF | RTC_IRQF);
679 }
680 
681 static void s3c6410_rtc_irq(struct s3c_rtc *info, int mask)
682 {
683 	rtc_update_irq(info->rtc, 1, RTC_AF | RTC_IRQF);
684 	writeb(mask, info->base + S3C2410_INTP);
685 }
686 
687 static void s3c2410_rtc_setfreq(struct s3c_rtc *info, int freq)
688 {
689 	unsigned int tmp = 0;
690 	int val;
691 
692 	tmp = readb(info->base + S3C2410_TICNT);
693 	tmp &= S3C2410_TICNT_ENABLE;
694 
695 	val = (info->rtc->max_user_freq / freq) - 1;
696 	tmp |= val;
697 
698 	writel(tmp, info->base + S3C2410_TICNT);
699 }
700 
701 static void s3c2416_rtc_setfreq(struct s3c_rtc *info, int freq)
702 {
703 	unsigned int tmp = 0;
704 	int val;
705 
706 	tmp = readb(info->base + S3C2410_TICNT);
707 	tmp &= S3C2410_TICNT_ENABLE;
708 
709 	val = (info->rtc->max_user_freq / freq) - 1;
710 
711 	tmp |= S3C2443_TICNT_PART(val);
712 	writel(S3C2443_TICNT1_PART(val), info->base + S3C2443_TICNT1);
713 
714 	writel(S3C2416_TICNT2_PART(val), info->base + S3C2416_TICNT2);
715 
716 	writel(tmp, info->base + S3C2410_TICNT);
717 }
718 
719 static void s3c2443_rtc_setfreq(struct s3c_rtc *info, int freq)
720 {
721 	unsigned int tmp = 0;
722 	int val;
723 
724 	tmp = readb(info->base + S3C2410_TICNT);
725 	tmp &= S3C2410_TICNT_ENABLE;
726 
727 	val = (info->rtc->max_user_freq / freq) - 1;
728 
729 	tmp |= S3C2443_TICNT_PART(val);
730 	writel(S3C2443_TICNT1_PART(val), info->base + S3C2443_TICNT1);
731 
732 	writel(tmp, info->base + S3C2410_TICNT);
733 }
734 
735 static void s3c6410_rtc_setfreq(struct s3c_rtc *info, int freq)
736 {
737 	int val;
738 
739 	val = (info->rtc->max_user_freq / freq) - 1;
740 	writel(val, info->base + S3C2410_TICNT);
741 }
742 
743 static void s3c24xx_rtc_enable_tick(struct s3c_rtc *info, struct seq_file *seq)
744 {
745 	unsigned int ticnt;
746 
747 	ticnt = readb(info->base + S3C2410_TICNT);
748 	ticnt &= S3C2410_TICNT_ENABLE;
749 
750 	seq_printf(seq, "periodic_IRQ\t: %s\n", ticnt  ? "yes" : "no");
751 }
752 
753 static void s3c2416_rtc_select_tick_clk(struct s3c_rtc *info)
754 {
755 	unsigned int con;
756 
757 	con = readw(info->base + S3C2410_RTCCON);
758 	con |= S3C2443_RTCCON_TICSEL;
759 	writew(con, info->base + S3C2410_RTCCON);
760 }
761 
762 static void s3c6410_rtc_enable_tick(struct s3c_rtc *info, struct seq_file *seq)
763 {
764 	unsigned int ticnt;
765 
766 	ticnt = readw(info->base + S3C2410_RTCCON);
767 	ticnt &= S3C64XX_RTCCON_TICEN;
768 
769 	seq_printf(seq, "periodic_IRQ\t: %s\n", ticnt  ? "yes" : "no");
770 }
771 
772 static void s3c24xx_rtc_save_tick_cnt(struct s3c_rtc *info)
773 {
774 	info->ticnt_save = readb(info->base + S3C2410_TICNT);
775 }
776 
777 static void s3c24xx_rtc_restore_tick_cnt(struct s3c_rtc *info)
778 {
779 	writeb(info->ticnt_save, info->base + S3C2410_TICNT);
780 }
781 
782 static void s3c6410_rtc_save_tick_cnt(struct s3c_rtc *info)
783 {
784 	info->ticnt_en_save = readw(info->base + S3C2410_RTCCON);
785 	info->ticnt_en_save &= S3C64XX_RTCCON_TICEN;
786 	info->ticnt_save = readl(info->base + S3C2410_TICNT);
787 }
788 
789 static void s3c6410_rtc_restore_tick_cnt(struct s3c_rtc *info)
790 {
791 	unsigned int con;
792 
793 	writel(info->ticnt_save, info->base + S3C2410_TICNT);
794 	if (info->ticnt_en_save) {
795 		con = readw(info->base + S3C2410_RTCCON);
796 		writew(con | info->ticnt_en_save, info->base + S3C2410_RTCCON);
797 	}
798 }
799 
800 static struct s3c_rtc_data const s3c2410_rtc_data = {
801 	.max_user_freq		= 128,
802 	.irq_handler		= s3c24xx_rtc_irq,
803 	.set_freq		= s3c2410_rtc_setfreq,
804 	.enable_tick		= s3c24xx_rtc_enable_tick,
805 	.save_tick_cnt		= s3c24xx_rtc_save_tick_cnt,
806 	.restore_tick_cnt	= s3c24xx_rtc_restore_tick_cnt,
807 	.enable			= s3c24xx_rtc_enable,
808 	.disable		= s3c24xx_rtc_disable,
809 };
810 
811 static struct s3c_rtc_data const s3c2416_rtc_data = {
812 	.max_user_freq		= 32768,
813 	.irq_handler		= s3c24xx_rtc_irq,
814 	.set_freq		= s3c2416_rtc_setfreq,
815 	.enable_tick		= s3c24xx_rtc_enable_tick,
816 	.select_tick_clk	= s3c2416_rtc_select_tick_clk,
817 	.save_tick_cnt		= s3c24xx_rtc_save_tick_cnt,
818 	.restore_tick_cnt	= s3c24xx_rtc_restore_tick_cnt,
819 	.enable			= s3c24xx_rtc_enable,
820 	.disable		= s3c24xx_rtc_disable,
821 };
822 
823 static struct s3c_rtc_data const s3c2443_rtc_data = {
824 	.max_user_freq		= 32768,
825 	.irq_handler		= s3c24xx_rtc_irq,
826 	.set_freq		= s3c2443_rtc_setfreq,
827 	.enable_tick		= s3c24xx_rtc_enable_tick,
828 	.select_tick_clk	= s3c2416_rtc_select_tick_clk,
829 	.save_tick_cnt		= s3c24xx_rtc_save_tick_cnt,
830 	.restore_tick_cnt	= s3c24xx_rtc_restore_tick_cnt,
831 	.enable			= s3c24xx_rtc_enable,
832 	.disable		= s3c24xx_rtc_disable,
833 };
834 
835 static struct s3c_rtc_data const s3c6410_rtc_data = {
836 	.max_user_freq		= 32768,
837 	.needs_src_clk		= true,
838 	.irq_handler		= s3c6410_rtc_irq,
839 	.set_freq		= s3c6410_rtc_setfreq,
840 	.enable_tick		= s3c6410_rtc_enable_tick,
841 	.save_tick_cnt		= s3c6410_rtc_save_tick_cnt,
842 	.restore_tick_cnt	= s3c6410_rtc_restore_tick_cnt,
843 	.enable			= s3c24xx_rtc_enable,
844 	.disable		= s3c6410_rtc_disable,
845 };
846 
847 static const struct of_device_id s3c_rtc_dt_match[] = {
848 	{
849 		.compatible = "samsung,s3c2410-rtc",
850 		.data = &s3c2410_rtc_data,
851 	}, {
852 		.compatible = "samsung,s3c2416-rtc",
853 		.data = &s3c2416_rtc_data,
854 	}, {
855 		.compatible = "samsung,s3c2443-rtc",
856 		.data = &s3c2443_rtc_data,
857 	}, {
858 		.compatible = "samsung,s3c6410-rtc",
859 		.data = &s3c6410_rtc_data,
860 	}, {
861 		.compatible = "samsung,exynos3250-rtc",
862 		.data = &s3c6410_rtc_data,
863 	},
864 	{ /* sentinel */ },
865 };
866 MODULE_DEVICE_TABLE(of, s3c_rtc_dt_match);
867 
868 static struct platform_driver s3c_rtc_driver = {
869 	.probe		= s3c_rtc_probe,
870 	.remove		= s3c_rtc_remove,
871 	.driver		= {
872 		.name	= "s3c-rtc",
873 		.pm	= &s3c_rtc_pm_ops,
874 		.of_match_table	= of_match_ptr(s3c_rtc_dt_match),
875 	},
876 };
877 module_platform_driver(s3c_rtc_driver);
878 
879 MODULE_DESCRIPTION("Samsung S3C RTC Driver");
880 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
881 MODULE_LICENSE("GPL");
882 MODULE_ALIAS("platform:s3c2410-rtc");
883