xref: /openbmc/linux/drivers/rtc/rtc-s3c.c (revision 2208f39c)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* drivers/rtc/rtc-s3c.c
3  *
4  * Copyright (c) 2010 Samsung Electronics Co., Ltd.
5  *		http://www.samsung.com/
6  *
7  * Copyright (c) 2004,2006 Simtec Electronics
8  *	Ben Dooks, <ben@simtec.co.uk>
9  *	http://armlinux.simtec.co.uk/
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 #include <linux/log2.h>
24 #include <linux/slab.h>
25 #include <linux/of.h>
26 #include <linux/of_device.h>
27 #include <linux/uaccess.h>
28 #include <linux/io.h>
29 
30 #include <asm/irq.h>
31 #include "rtc-s3c.h"
32 
33 struct s3c_rtc {
34 	struct device *dev;
35 	struct rtc_device *rtc;
36 
37 	void __iomem *base;
38 	struct clk *rtc_clk;
39 	struct clk *rtc_src_clk;
40 	bool alarm_enabled;
41 
42 	const struct s3c_rtc_data *data;
43 
44 	int irq_alarm;
45 	int irq_tick;
46 
47 	spinlock_t pie_lock;
48 	spinlock_t alarm_lock;
49 
50 	int ticnt_save;
51 	int ticnt_en_save;
52 	bool wake_en;
53 };
54 
55 struct s3c_rtc_data {
56 	int max_user_freq;
57 	bool needs_src_clk;
58 
59 	void (*irq_handler) (struct s3c_rtc *info, int mask);
60 	void (*set_freq) (struct s3c_rtc *info, int freq);
61 	void (*enable_tick) (struct s3c_rtc *info, struct seq_file *seq);
62 	void (*select_tick_clk) (struct s3c_rtc *info);
63 	void (*save_tick_cnt) (struct s3c_rtc *info);
64 	void (*restore_tick_cnt) (struct s3c_rtc *info);
65 	void (*enable) (struct s3c_rtc *info);
66 	void (*disable) (struct s3c_rtc *info);
67 };
68 
69 static int s3c_rtc_enable_clk(struct s3c_rtc *info)
70 {
71 	int ret;
72 
73 	ret = clk_enable(info->rtc_clk);
74 	if (ret)
75 		return ret;
76 
77 	if (info->data->needs_src_clk) {
78 		ret = clk_enable(info->rtc_src_clk);
79 		if (ret) {
80 			clk_disable(info->rtc_clk);
81 			return ret;
82 		}
83 	}
84 	return 0;
85 }
86 
87 static void s3c_rtc_disable_clk(struct s3c_rtc *info)
88 {
89 	if (info->data->needs_src_clk)
90 		clk_disable(info->rtc_src_clk);
91 	clk_disable(info->rtc_clk);
92 }
93 
94 /* IRQ Handlers */
95 static irqreturn_t s3c_rtc_tickirq(int irq, void *id)
96 {
97 	struct s3c_rtc *info = (struct s3c_rtc *)id;
98 
99 	if (info->data->irq_handler)
100 		info->data->irq_handler(info, S3C2410_INTP_TIC);
101 
102 	return IRQ_HANDLED;
103 }
104 
105 static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)
106 {
107 	struct s3c_rtc *info = (struct s3c_rtc *)id;
108 
109 	if (info->data->irq_handler)
110 		info->data->irq_handler(info, S3C2410_INTP_ALM);
111 
112 	return IRQ_HANDLED;
113 }
114 
115 /* Update control registers */
116 static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
117 {
118 	struct s3c_rtc *info = dev_get_drvdata(dev);
119 	unsigned long flags;
120 	unsigned int tmp;
121 	int ret;
122 
123 	dev_dbg(info->dev, "%s: aie=%d\n", __func__, enabled);
124 
125 	ret = s3c_rtc_enable_clk(info);
126 	if (ret)
127 		return ret;
128 
129 	tmp = readb(info->base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;
130 
131 	if (enabled)
132 		tmp |= S3C2410_RTCALM_ALMEN;
133 
134 	writeb(tmp, info->base + S3C2410_RTCALM);
135 
136 	spin_lock_irqsave(&info->alarm_lock, flags);
137 
138 	if (info->alarm_enabled && !enabled)
139 		s3c_rtc_disable_clk(info);
140 	else if (!info->alarm_enabled && enabled)
141 		ret = s3c_rtc_enable_clk(info);
142 
143 	info->alarm_enabled = enabled;
144 	spin_unlock_irqrestore(&info->alarm_lock, flags);
145 
146 	s3c_rtc_disable_clk(info);
147 
148 	return ret;
149 }
150 
151 /* Set RTC frequency */
152 static int s3c_rtc_setfreq(struct s3c_rtc *info, int freq)
153 {
154 	int ret;
155 
156 	if (!is_power_of_2(freq))
157 		return -EINVAL;
158 
159 	ret = s3c_rtc_enable_clk(info);
160 	if (ret)
161 		return ret;
162 	spin_lock_irq(&info->pie_lock);
163 
164 	if (info->data->set_freq)
165 		info->data->set_freq(info, freq);
166 
167 	spin_unlock_irq(&info->pie_lock);
168 	s3c_rtc_disable_clk(info);
169 
170 	return 0;
171 }
172 
173 /* Time read/write */
174 static int s3c_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
175 {
176 	struct s3c_rtc *info = dev_get_drvdata(dev);
177 	unsigned int have_retried = 0;
178 	int ret;
179 
180 	ret = s3c_rtc_enable_clk(info);
181 	if (ret)
182 		return ret;
183 
184 retry_get_time:
185 	rtc_tm->tm_min  = readb(info->base + S3C2410_RTCMIN);
186 	rtc_tm->tm_hour = readb(info->base + S3C2410_RTCHOUR);
187 	rtc_tm->tm_mday = readb(info->base + S3C2410_RTCDATE);
188 	rtc_tm->tm_mon  = readb(info->base + S3C2410_RTCMON);
189 	rtc_tm->tm_year = readb(info->base + S3C2410_RTCYEAR);
190 	rtc_tm->tm_sec  = readb(info->base + S3C2410_RTCSEC);
191 
192 	/* the only way to work out whether the system was mid-update
193 	 * when we read it is to check the second counter, and if it
194 	 * is zero, then we re-try the entire read
195 	 */
196 
197 	if (rtc_tm->tm_sec == 0 && !have_retried) {
198 		have_retried = 1;
199 		goto retry_get_time;
200 	}
201 
202 	rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
203 	rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
204 	rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
205 	rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
206 	rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
207 	rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
208 
209 	s3c_rtc_disable_clk(info);
210 
211 	rtc_tm->tm_year += 100;
212 	rtc_tm->tm_mon -= 1;
213 
214 	dev_dbg(dev, "read time %ptR\n", rtc_tm);
215 	return 0;
216 }
217 
218 static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
219 {
220 	struct s3c_rtc *info = dev_get_drvdata(dev);
221 	int year = tm->tm_year - 100;
222 	int ret;
223 
224 	dev_dbg(dev, "set time %ptR\n", tm);
225 
226 	/* we get around y2k by simply not supporting it */
227 
228 	if (year < 0 || year >= 100) {
229 		dev_err(dev, "rtc only supports 100 years\n");
230 		return -EINVAL;
231 	}
232 
233 	ret = s3c_rtc_enable_clk(info);
234 	if (ret)
235 		return ret;
236 
237 	writeb(bin2bcd(tm->tm_sec),  info->base + S3C2410_RTCSEC);
238 	writeb(bin2bcd(tm->tm_min),  info->base + S3C2410_RTCMIN);
239 	writeb(bin2bcd(tm->tm_hour), info->base + S3C2410_RTCHOUR);
240 	writeb(bin2bcd(tm->tm_mday), info->base + S3C2410_RTCDATE);
241 	writeb(bin2bcd(tm->tm_mon + 1), info->base + S3C2410_RTCMON);
242 	writeb(bin2bcd(year), info->base + S3C2410_RTCYEAR);
243 
244 	s3c_rtc_disable_clk(info);
245 
246 	return 0;
247 }
248 
249 static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
250 {
251 	struct s3c_rtc *info = dev_get_drvdata(dev);
252 	struct rtc_time *alm_tm = &alrm->time;
253 	unsigned int alm_en;
254 	int ret;
255 
256 	ret = s3c_rtc_enable_clk(info);
257 	if (ret)
258 		return ret;
259 
260 	alm_tm->tm_sec  = readb(info->base + S3C2410_ALMSEC);
261 	alm_tm->tm_min  = readb(info->base + S3C2410_ALMMIN);
262 	alm_tm->tm_hour = readb(info->base + S3C2410_ALMHOUR);
263 	alm_tm->tm_mon  = readb(info->base + S3C2410_ALMMON);
264 	alm_tm->tm_mday = readb(info->base + S3C2410_ALMDATE);
265 	alm_tm->tm_year = readb(info->base + S3C2410_ALMYEAR);
266 
267 	alm_en = readb(info->base + S3C2410_RTCALM);
268 
269 	s3c_rtc_disable_clk(info);
270 
271 	alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;
272 
273 	dev_dbg(dev, "read alarm %d, %ptR\n", alm_en, alm_tm);
274 
275 	/* decode the alarm enable field */
276 	if (alm_en & S3C2410_RTCALM_SECEN)
277 		alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
278 
279 	if (alm_en & S3C2410_RTCALM_MINEN)
280 		alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
281 
282 	if (alm_en & S3C2410_RTCALM_HOUREN)
283 		alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
284 
285 	if (alm_en & S3C2410_RTCALM_DAYEN)
286 		alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);
287 
288 	if (alm_en & S3C2410_RTCALM_MONEN) {
289 		alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon);
290 		alm_tm->tm_mon -= 1;
291 	}
292 
293 	if (alm_en & S3C2410_RTCALM_YEAREN)
294 		alm_tm->tm_year = bcd2bin(alm_tm->tm_year);
295 
296 	return 0;
297 }
298 
299 static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
300 {
301 	struct s3c_rtc *info = dev_get_drvdata(dev);
302 	struct rtc_time *tm = &alrm->time;
303 	unsigned int alrm_en;
304 	int ret;
305 
306 	dev_dbg(dev, "s3c_rtc_setalarm: %d, %ptR\n", alrm->enabled, tm);
307 
308 	ret = s3c_rtc_enable_clk(info);
309 	if (ret)
310 		return ret;
311 
312 	alrm_en = readb(info->base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;
313 	writeb(0x00, info->base + S3C2410_RTCALM);
314 
315 	if (tm->tm_sec < 60 && tm->tm_sec >= 0) {
316 		alrm_en |= S3C2410_RTCALM_SECEN;
317 		writeb(bin2bcd(tm->tm_sec), info->base + S3C2410_ALMSEC);
318 	}
319 
320 	if (tm->tm_min < 60 && tm->tm_min >= 0) {
321 		alrm_en |= S3C2410_RTCALM_MINEN;
322 		writeb(bin2bcd(tm->tm_min), info->base + S3C2410_ALMMIN);
323 	}
324 
325 	if (tm->tm_hour < 24 && tm->tm_hour >= 0) {
326 		alrm_en |= S3C2410_RTCALM_HOUREN;
327 		writeb(bin2bcd(tm->tm_hour), info->base + S3C2410_ALMHOUR);
328 	}
329 
330 	if (tm->tm_mon < 12 && tm->tm_mon >= 0) {
331 		alrm_en |= S3C2410_RTCALM_MONEN;
332 		writeb(bin2bcd(tm->tm_mon + 1), info->base + S3C2410_ALMMON);
333 	}
334 
335 	if (tm->tm_mday <= 31 && tm->tm_mday >= 1) {
336 		alrm_en |= S3C2410_RTCALM_DAYEN;
337 		writeb(bin2bcd(tm->tm_mday), info->base + S3C2410_ALMDATE);
338 	}
339 
340 	dev_dbg(dev, "setting S3C2410_RTCALM to %08x\n", alrm_en);
341 
342 	writeb(alrm_en, info->base + S3C2410_RTCALM);
343 
344 	s3c_rtc_setaie(dev, alrm->enabled);
345 
346 	s3c_rtc_disable_clk(info);
347 
348 	return 0;
349 }
350 
351 static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
352 {
353 	struct s3c_rtc *info = dev_get_drvdata(dev);
354 	int ret;
355 
356 	ret = s3c_rtc_enable_clk(info);
357 	if (ret)
358 		return ret;
359 
360 	if (info->data->enable_tick)
361 		info->data->enable_tick(info, seq);
362 
363 	s3c_rtc_disable_clk(info);
364 
365 	return 0;
366 }
367 
368 static const struct rtc_class_ops s3c_rtcops = {
369 	.read_time	= s3c_rtc_gettime,
370 	.set_time	= s3c_rtc_settime,
371 	.read_alarm	= s3c_rtc_getalarm,
372 	.set_alarm	= s3c_rtc_setalarm,
373 	.proc		= s3c_rtc_proc,
374 	.alarm_irq_enable = s3c_rtc_setaie,
375 };
376 
377 static void s3c24xx_rtc_enable(struct s3c_rtc *info)
378 {
379 	unsigned int con, tmp;
380 
381 	con = readw(info->base + S3C2410_RTCCON);
382 	/* re-enable the device, and check it is ok */
383 	if ((con & S3C2410_RTCCON_RTCEN) == 0) {
384 		dev_info(info->dev, "rtc disabled, re-enabling\n");
385 
386 		tmp = readw(info->base + S3C2410_RTCCON);
387 		writew(tmp | S3C2410_RTCCON_RTCEN, info->base + S3C2410_RTCCON);
388 	}
389 
390 	if (con & S3C2410_RTCCON_CNTSEL) {
391 		dev_info(info->dev, "removing RTCCON_CNTSEL\n");
392 
393 		tmp = readw(info->base + S3C2410_RTCCON);
394 		writew(tmp & ~S3C2410_RTCCON_CNTSEL,
395 		       info->base + S3C2410_RTCCON);
396 	}
397 
398 	if (con & S3C2410_RTCCON_CLKRST) {
399 		dev_info(info->dev, "removing RTCCON_CLKRST\n");
400 
401 		tmp = readw(info->base + S3C2410_RTCCON);
402 		writew(tmp & ~S3C2410_RTCCON_CLKRST,
403 		       info->base + S3C2410_RTCCON);
404 	}
405 }
406 
407 static void s3c24xx_rtc_disable(struct s3c_rtc *info)
408 {
409 	unsigned int con;
410 
411 	con = readw(info->base + S3C2410_RTCCON);
412 	con &= ~S3C2410_RTCCON_RTCEN;
413 	writew(con, info->base + S3C2410_RTCCON);
414 
415 	con = readb(info->base + S3C2410_TICNT);
416 	con &= ~S3C2410_TICNT_ENABLE;
417 	writeb(con, info->base + S3C2410_TICNT);
418 }
419 
420 static void s3c6410_rtc_disable(struct s3c_rtc *info)
421 {
422 	unsigned int con;
423 
424 	con = readw(info->base + S3C2410_RTCCON);
425 	con &= ~S3C64XX_RTCCON_TICEN;
426 	con &= ~S3C2410_RTCCON_RTCEN;
427 	writew(con, info->base + S3C2410_RTCCON);
428 }
429 
430 static int s3c_rtc_remove(struct platform_device *pdev)
431 {
432 	struct s3c_rtc *info = platform_get_drvdata(pdev);
433 
434 	s3c_rtc_setaie(info->dev, 0);
435 
436 	if (info->data->needs_src_clk)
437 		clk_unprepare(info->rtc_src_clk);
438 	clk_unprepare(info->rtc_clk);
439 
440 	return 0;
441 }
442 
443 static int s3c_rtc_probe(struct platform_device *pdev)
444 {
445 	struct s3c_rtc *info = NULL;
446 	struct rtc_time rtc_tm;
447 	int ret;
448 
449 	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
450 	if (!info)
451 		return -ENOMEM;
452 
453 	/* find the IRQs */
454 	info->irq_tick = platform_get_irq(pdev, 1);
455 	if (info->irq_tick < 0)
456 		return info->irq_tick;
457 
458 	info->dev = &pdev->dev;
459 	info->data = of_device_get_match_data(&pdev->dev);
460 	if (!info->data) {
461 		dev_err(&pdev->dev, "failed getting s3c_rtc_data\n");
462 		return -EINVAL;
463 	}
464 	spin_lock_init(&info->pie_lock);
465 	spin_lock_init(&info->alarm_lock);
466 
467 	platform_set_drvdata(pdev, info);
468 
469 	info->irq_alarm = platform_get_irq(pdev, 0);
470 	if (info->irq_alarm < 0)
471 		return info->irq_alarm;
472 
473 	dev_dbg(&pdev->dev, "s3c2410_rtc: tick irq %d, alarm irq %d\n",
474 		info->irq_tick, info->irq_alarm);
475 
476 	/* get the memory region */
477 	info->base = devm_platform_ioremap_resource(pdev, 0);
478 	if (IS_ERR(info->base))
479 		return PTR_ERR(info->base);
480 
481 	info->rtc_clk = devm_clk_get(&pdev->dev, "rtc");
482 	if (IS_ERR(info->rtc_clk)) {
483 		ret = PTR_ERR(info->rtc_clk);
484 		if (ret != -EPROBE_DEFER)
485 			dev_err(&pdev->dev, "failed to find rtc clock\n");
486 		else
487 			dev_dbg(&pdev->dev, "probe deferred due to missing rtc clk\n");
488 		return ret;
489 	}
490 	ret = clk_prepare_enable(info->rtc_clk);
491 	if (ret)
492 		return ret;
493 
494 	if (info->data->needs_src_clk) {
495 		info->rtc_src_clk = devm_clk_get(&pdev->dev, "rtc_src");
496 		if (IS_ERR(info->rtc_src_clk)) {
497 			ret = dev_err_probe(&pdev->dev, PTR_ERR(info->rtc_src_clk),
498 					    "failed to find rtc source clock\n");
499 			goto err_src_clk;
500 		}
501 		ret = clk_prepare_enable(info->rtc_src_clk);
502 		if (ret)
503 			goto err_src_clk;
504 	}
505 
506 	/* check to see if everything is setup correctly */
507 	if (info->data->enable)
508 		info->data->enable(info);
509 
510 	dev_dbg(&pdev->dev, "s3c2410_rtc: RTCCON=%02x\n",
511 		readw(info->base + S3C2410_RTCCON));
512 
513 	device_init_wakeup(&pdev->dev, 1);
514 
515 	/* Check RTC Time */
516 	if (s3c_rtc_gettime(&pdev->dev, &rtc_tm)) {
517 		rtc_tm.tm_year	= 100;
518 		rtc_tm.tm_mon	= 0;
519 		rtc_tm.tm_mday	= 1;
520 		rtc_tm.tm_hour	= 0;
521 		rtc_tm.tm_min	= 0;
522 		rtc_tm.tm_sec	= 0;
523 
524 		s3c_rtc_settime(&pdev->dev, &rtc_tm);
525 
526 		dev_warn(&pdev->dev, "warning: invalid RTC value so initializing it\n");
527 	}
528 
529 	/* register RTC and exit */
530 	info->rtc = devm_rtc_device_register(&pdev->dev, "s3c", &s3c_rtcops,
531 					     THIS_MODULE);
532 	if (IS_ERR(info->rtc)) {
533 		dev_err(&pdev->dev, "cannot attach rtc\n");
534 		ret = PTR_ERR(info->rtc);
535 		goto err_nortc;
536 	}
537 
538 	ret = devm_request_irq(&pdev->dev, info->irq_alarm, s3c_rtc_alarmirq,
539 			       0, "s3c2410-rtc alarm", info);
540 	if (ret) {
541 		dev_err(&pdev->dev, "IRQ%d error %d\n", info->irq_alarm, ret);
542 		goto err_nortc;
543 	}
544 
545 	ret = devm_request_irq(&pdev->dev, info->irq_tick, s3c_rtc_tickirq,
546 			       0, "s3c2410-rtc tick", info);
547 	if (ret) {
548 		dev_err(&pdev->dev, "IRQ%d error %d\n", info->irq_tick, ret);
549 		goto err_nortc;
550 	}
551 
552 	if (info->data->select_tick_clk)
553 		info->data->select_tick_clk(info);
554 
555 	s3c_rtc_setfreq(info, 1);
556 
557 	s3c_rtc_disable_clk(info);
558 
559 	return 0;
560 
561 err_nortc:
562 	if (info->data->disable)
563 		info->data->disable(info);
564 
565 	if (info->data->needs_src_clk)
566 		clk_disable_unprepare(info->rtc_src_clk);
567 err_src_clk:
568 	clk_disable_unprepare(info->rtc_clk);
569 
570 	return ret;
571 }
572 
573 #ifdef CONFIG_PM_SLEEP
574 
575 static int s3c_rtc_suspend(struct device *dev)
576 {
577 	struct s3c_rtc *info = dev_get_drvdata(dev);
578 	int ret;
579 
580 	ret = s3c_rtc_enable_clk(info);
581 	if (ret)
582 		return ret;
583 
584 	/* save TICNT for anyone using periodic interrupts */
585 	if (info->data->save_tick_cnt)
586 		info->data->save_tick_cnt(info);
587 
588 	if (info->data->disable)
589 		info->data->disable(info);
590 
591 	if (device_may_wakeup(dev) && !info->wake_en) {
592 		if (enable_irq_wake(info->irq_alarm) == 0)
593 			info->wake_en = true;
594 		else
595 			dev_err(dev, "enable_irq_wake failed\n");
596 	}
597 
598 	return 0;
599 }
600 
601 static int s3c_rtc_resume(struct device *dev)
602 {
603 	struct s3c_rtc *info = dev_get_drvdata(dev);
604 
605 	if (info->data->enable)
606 		info->data->enable(info);
607 
608 	if (info->data->restore_tick_cnt)
609 		info->data->restore_tick_cnt(info);
610 
611 	s3c_rtc_disable_clk(info);
612 
613 	if (device_may_wakeup(dev) && info->wake_en) {
614 		disable_irq_wake(info->irq_alarm);
615 		info->wake_en = false;
616 	}
617 
618 	return 0;
619 }
620 #endif
621 static SIMPLE_DEV_PM_OPS(s3c_rtc_pm_ops, s3c_rtc_suspend, s3c_rtc_resume);
622 
623 static void s3c24xx_rtc_irq(struct s3c_rtc *info, int mask)
624 {
625 	rtc_update_irq(info->rtc, 1, RTC_AF | RTC_IRQF);
626 }
627 
628 static void s3c6410_rtc_irq(struct s3c_rtc *info, int mask)
629 {
630 	rtc_update_irq(info->rtc, 1, RTC_AF | RTC_IRQF);
631 	writeb(mask, info->base + S3C2410_INTP);
632 }
633 
634 static void s3c2410_rtc_setfreq(struct s3c_rtc *info, int freq)
635 {
636 	unsigned int tmp = 0;
637 	int val;
638 
639 	tmp = readb(info->base + S3C2410_TICNT);
640 	tmp &= S3C2410_TICNT_ENABLE;
641 
642 	val = (info->rtc->max_user_freq / freq) - 1;
643 	tmp |= val;
644 
645 	writel(tmp, info->base + S3C2410_TICNT);
646 }
647 
648 static void s3c2416_rtc_setfreq(struct s3c_rtc *info, int freq)
649 {
650 	unsigned int tmp = 0;
651 	int val;
652 
653 	tmp = readb(info->base + S3C2410_TICNT);
654 	tmp &= S3C2410_TICNT_ENABLE;
655 
656 	val = (info->rtc->max_user_freq / freq) - 1;
657 
658 	tmp |= S3C2443_TICNT_PART(val);
659 	writel(S3C2443_TICNT1_PART(val), info->base + S3C2443_TICNT1);
660 
661 	writel(S3C2416_TICNT2_PART(val), info->base + S3C2416_TICNT2);
662 
663 	writel(tmp, info->base + S3C2410_TICNT);
664 }
665 
666 static void s3c2443_rtc_setfreq(struct s3c_rtc *info, int freq)
667 {
668 	unsigned int tmp = 0;
669 	int val;
670 
671 	tmp = readb(info->base + S3C2410_TICNT);
672 	tmp &= S3C2410_TICNT_ENABLE;
673 
674 	val = (info->rtc->max_user_freq / freq) - 1;
675 
676 	tmp |= S3C2443_TICNT_PART(val);
677 	writel(S3C2443_TICNT1_PART(val), info->base + S3C2443_TICNT1);
678 
679 	writel(tmp, info->base + S3C2410_TICNT);
680 }
681 
682 static void s3c6410_rtc_setfreq(struct s3c_rtc *info, int freq)
683 {
684 	int val;
685 
686 	val = (info->rtc->max_user_freq / freq) - 1;
687 	writel(val, info->base + S3C2410_TICNT);
688 }
689 
690 static void s3c24xx_rtc_enable_tick(struct s3c_rtc *info, struct seq_file *seq)
691 {
692 	unsigned int ticnt;
693 
694 	ticnt = readb(info->base + S3C2410_TICNT);
695 	ticnt &= S3C2410_TICNT_ENABLE;
696 
697 	seq_printf(seq, "periodic_IRQ\t: %s\n", ticnt  ? "yes" : "no");
698 }
699 
700 static void s3c2416_rtc_select_tick_clk(struct s3c_rtc *info)
701 {
702 	unsigned int con;
703 
704 	con = readw(info->base + S3C2410_RTCCON);
705 	con |= S3C2443_RTCCON_TICSEL;
706 	writew(con, info->base + S3C2410_RTCCON);
707 }
708 
709 static void s3c6410_rtc_enable_tick(struct s3c_rtc *info, struct seq_file *seq)
710 {
711 	unsigned int ticnt;
712 
713 	ticnt = readw(info->base + S3C2410_RTCCON);
714 	ticnt &= S3C64XX_RTCCON_TICEN;
715 
716 	seq_printf(seq, "periodic_IRQ\t: %s\n", ticnt  ? "yes" : "no");
717 }
718 
719 static void s3c24xx_rtc_save_tick_cnt(struct s3c_rtc *info)
720 {
721 	info->ticnt_save = readb(info->base + S3C2410_TICNT);
722 }
723 
724 static void s3c24xx_rtc_restore_tick_cnt(struct s3c_rtc *info)
725 {
726 	writeb(info->ticnt_save, info->base + S3C2410_TICNT);
727 }
728 
729 static void s3c6410_rtc_save_tick_cnt(struct s3c_rtc *info)
730 {
731 	info->ticnt_en_save = readw(info->base + S3C2410_RTCCON);
732 	info->ticnt_en_save &= S3C64XX_RTCCON_TICEN;
733 	info->ticnt_save = readl(info->base + S3C2410_TICNT);
734 }
735 
736 static void s3c6410_rtc_restore_tick_cnt(struct s3c_rtc *info)
737 {
738 	unsigned int con;
739 
740 	writel(info->ticnt_save, info->base + S3C2410_TICNT);
741 	if (info->ticnt_en_save) {
742 		con = readw(info->base + S3C2410_RTCCON);
743 		writew(con | info->ticnt_en_save, info->base + S3C2410_RTCCON);
744 	}
745 }
746 
747 static struct s3c_rtc_data const s3c2410_rtc_data = {
748 	.max_user_freq		= 128,
749 	.irq_handler		= s3c24xx_rtc_irq,
750 	.set_freq		= s3c2410_rtc_setfreq,
751 	.enable_tick		= s3c24xx_rtc_enable_tick,
752 	.save_tick_cnt		= s3c24xx_rtc_save_tick_cnt,
753 	.restore_tick_cnt	= s3c24xx_rtc_restore_tick_cnt,
754 	.enable			= s3c24xx_rtc_enable,
755 	.disable		= s3c24xx_rtc_disable,
756 };
757 
758 static struct s3c_rtc_data const s3c2416_rtc_data = {
759 	.max_user_freq		= 32768,
760 	.irq_handler		= s3c24xx_rtc_irq,
761 	.set_freq		= s3c2416_rtc_setfreq,
762 	.enable_tick		= s3c24xx_rtc_enable_tick,
763 	.select_tick_clk	= s3c2416_rtc_select_tick_clk,
764 	.save_tick_cnt		= s3c24xx_rtc_save_tick_cnt,
765 	.restore_tick_cnt	= s3c24xx_rtc_restore_tick_cnt,
766 	.enable			= s3c24xx_rtc_enable,
767 	.disable		= s3c24xx_rtc_disable,
768 };
769 
770 static struct s3c_rtc_data const s3c2443_rtc_data = {
771 	.max_user_freq		= 32768,
772 	.irq_handler		= s3c24xx_rtc_irq,
773 	.set_freq		= s3c2443_rtc_setfreq,
774 	.enable_tick		= s3c24xx_rtc_enable_tick,
775 	.select_tick_clk	= s3c2416_rtc_select_tick_clk,
776 	.save_tick_cnt		= s3c24xx_rtc_save_tick_cnt,
777 	.restore_tick_cnt	= s3c24xx_rtc_restore_tick_cnt,
778 	.enable			= s3c24xx_rtc_enable,
779 	.disable		= s3c24xx_rtc_disable,
780 };
781 
782 static struct s3c_rtc_data const s3c6410_rtc_data = {
783 	.max_user_freq		= 32768,
784 	.needs_src_clk		= true,
785 	.irq_handler		= s3c6410_rtc_irq,
786 	.set_freq		= s3c6410_rtc_setfreq,
787 	.enable_tick		= s3c6410_rtc_enable_tick,
788 	.save_tick_cnt		= s3c6410_rtc_save_tick_cnt,
789 	.restore_tick_cnt	= s3c6410_rtc_restore_tick_cnt,
790 	.enable			= s3c24xx_rtc_enable,
791 	.disable		= s3c6410_rtc_disable,
792 };
793 
794 static const struct of_device_id s3c_rtc_dt_match[] = {
795 	{
796 		.compatible = "samsung,s3c2410-rtc",
797 		.data = &s3c2410_rtc_data,
798 	}, {
799 		.compatible = "samsung,s3c2416-rtc",
800 		.data = &s3c2416_rtc_data,
801 	}, {
802 		.compatible = "samsung,s3c2443-rtc",
803 		.data = &s3c2443_rtc_data,
804 	}, {
805 		.compatible = "samsung,s3c6410-rtc",
806 		.data = &s3c6410_rtc_data,
807 	}, {
808 		.compatible = "samsung,exynos3250-rtc",
809 		.data = &s3c6410_rtc_data,
810 	},
811 	{ /* sentinel */ },
812 };
813 MODULE_DEVICE_TABLE(of, s3c_rtc_dt_match);
814 
815 static struct platform_driver s3c_rtc_driver = {
816 	.probe		= s3c_rtc_probe,
817 	.remove		= s3c_rtc_remove,
818 	.driver		= {
819 		.name	= "s3c-rtc",
820 		.pm	= &s3c_rtc_pm_ops,
821 		.of_match_table	= of_match_ptr(s3c_rtc_dt_match),
822 	},
823 };
824 module_platform_driver(s3c_rtc_driver);
825 
826 MODULE_DESCRIPTION("Samsung S3C RTC Driver");
827 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
828 MODULE_LICENSE("GPL");
829 MODULE_ALIAS("platform:s3c2410-rtc");
830