xref: /openbmc/linux/drivers/rtc/rtc-sh.c (revision 5b394b2d)
1 /*
2  * SuperH On-Chip RTC Support
3  *
4  * Copyright (C) 2006 - 2009  Paul Mundt
5  * Copyright (C) 2006  Jamie Lenehan
6  * Copyright (C) 2008  Angelo Castello
7  *
8  * Based on the old arch/sh/kernel/cpu/rtc.c by:
9  *
10  *  Copyright (C) 2000  Philipp Rumpf <prumpf@tux.org>
11  *  Copyright (C) 1999  Tetsuya Okada & Niibe Yutaka
12  *
13  * This file is subject to the terms and conditions of the GNU General Public
14  * License.  See the file "COPYING" in the main directory of this archive
15  * for more details.
16  */
17 #include <linux/module.h>
18 #include <linux/mod_devicetable.h>
19 #include <linux/kernel.h>
20 #include <linux/bcd.h>
21 #include <linux/rtc.h>
22 #include <linux/init.h>
23 #include <linux/platform_device.h>
24 #include <linux/seq_file.h>
25 #include <linux/interrupt.h>
26 #include <linux/spinlock.h>
27 #include <linux/io.h>
28 #include <linux/log2.h>
29 #include <linux/clk.h>
30 #include <linux/slab.h>
31 #ifdef CONFIG_SUPERH
32 #include <asm/rtc.h>
33 #else
34 /* Default values for RZ/A RTC */
35 #define rtc_reg_size		sizeof(u16)
36 #define RTC_BIT_INVERTED        0	/* no chip bugs */
37 #define RTC_CAP_4_DIGIT_YEAR    (1 << 0)
38 #define RTC_DEF_CAPABILITIES    RTC_CAP_4_DIGIT_YEAR
39 #endif
40 
41 #define DRV_NAME	"sh-rtc"
42 
43 #define RTC_REG(r)	((r) * rtc_reg_size)
44 
45 #define R64CNT		RTC_REG(0)
46 
47 #define RSECCNT		RTC_REG(1)	/* RTC sec */
48 #define RMINCNT		RTC_REG(2)	/* RTC min */
49 #define RHRCNT		RTC_REG(3)	/* RTC hour */
50 #define RWKCNT		RTC_REG(4)	/* RTC week */
51 #define RDAYCNT		RTC_REG(5)	/* RTC day */
52 #define RMONCNT		RTC_REG(6)	/* RTC month */
53 #define RYRCNT		RTC_REG(7)	/* RTC year */
54 #define RSECAR		RTC_REG(8)	/* ALARM sec */
55 #define RMINAR		RTC_REG(9)	/* ALARM min */
56 #define RHRAR		RTC_REG(10)	/* ALARM hour */
57 #define RWKAR		RTC_REG(11)	/* ALARM week */
58 #define RDAYAR		RTC_REG(12)	/* ALARM day */
59 #define RMONAR		RTC_REG(13)	/* ALARM month */
60 #define RCR1		RTC_REG(14)	/* Control */
61 #define RCR2		RTC_REG(15)	/* Control */
62 
63 /*
64  * Note on RYRAR and RCR3: Up until this point most of the register
65  * definitions are consistent across all of the available parts. However,
66  * the placement of the optional RYRAR and RCR3 (the RYRAR control
67  * register used to control RYRCNT/RYRAR compare) varies considerably
68  * across various parts, occasionally being mapped in to a completely
69  * unrelated address space. For proper RYRAR support a separate resource
70  * would have to be handed off, but as this is purely optional in
71  * practice, we simply opt not to support it, thereby keeping the code
72  * quite a bit more simplified.
73  */
74 
75 /* ALARM Bits - or with BCD encoded value */
76 #define AR_ENB		0x80	/* Enable for alarm cmp   */
77 
78 /* Period Bits */
79 #define PF_HP		0x100	/* Enable Half Period to support 8,32,128Hz */
80 #define PF_COUNT	0x200	/* Half periodic counter */
81 #define PF_OXS		0x400	/* Periodic One x Second */
82 #define PF_KOU		0x800	/* Kernel or User periodic request 1=kernel */
83 #define PF_MASK		0xf00
84 
85 /* RCR1 Bits */
86 #define RCR1_CF		0x80	/* Carry Flag             */
87 #define RCR1_CIE	0x10	/* Carry Interrupt Enable */
88 #define RCR1_AIE	0x08	/* Alarm Interrupt Enable */
89 #define RCR1_AF		0x01	/* Alarm Flag             */
90 
91 /* RCR2 Bits */
92 #define RCR2_PEF	0x80	/* PEriodic interrupt Flag */
93 #define RCR2_PESMASK	0x70	/* Periodic interrupt Set  */
94 #define RCR2_RTCEN	0x08	/* ENable RTC              */
95 #define RCR2_ADJ	0x04	/* ADJustment (30-second)  */
96 #define RCR2_RESET	0x02	/* Reset bit               */
97 #define RCR2_START	0x01	/* Start bit               */
98 
99 struct sh_rtc {
100 	void __iomem		*regbase;
101 	unsigned long		regsize;
102 	struct resource		*res;
103 	int			alarm_irq;
104 	int			periodic_irq;
105 	int			carry_irq;
106 	struct clk		*clk;
107 	struct rtc_device	*rtc_dev;
108 	spinlock_t		lock;
109 	unsigned long		capabilities;	/* See asm/rtc.h for cap bits */
110 	unsigned short		periodic_freq;
111 };
112 
113 static int __sh_rtc_interrupt(struct sh_rtc *rtc)
114 {
115 	unsigned int tmp, pending;
116 
117 	tmp = readb(rtc->regbase + RCR1);
118 	pending = tmp & RCR1_CF;
119 	tmp &= ~RCR1_CF;
120 	writeb(tmp, rtc->regbase + RCR1);
121 
122 	/* Users have requested One x Second IRQ */
123 	if (pending && rtc->periodic_freq & PF_OXS)
124 		rtc_update_irq(rtc->rtc_dev, 1, RTC_UF | RTC_IRQF);
125 
126 	return pending;
127 }
128 
129 static int __sh_rtc_alarm(struct sh_rtc *rtc)
130 {
131 	unsigned int tmp, pending;
132 
133 	tmp = readb(rtc->regbase + RCR1);
134 	pending = tmp & RCR1_AF;
135 	tmp &= ~(RCR1_AF | RCR1_AIE);
136 	writeb(tmp, rtc->regbase + RCR1);
137 
138 	if (pending)
139 		rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF);
140 
141 	return pending;
142 }
143 
144 static int __sh_rtc_periodic(struct sh_rtc *rtc)
145 {
146 	unsigned int tmp, pending;
147 
148 	tmp = readb(rtc->regbase + RCR2);
149 	pending = tmp & RCR2_PEF;
150 	tmp &= ~RCR2_PEF;
151 	writeb(tmp, rtc->regbase + RCR2);
152 
153 	if (!pending)
154 		return 0;
155 
156 	/* Half period enabled than one skipped and the next notified */
157 	if ((rtc->periodic_freq & PF_HP) && (rtc->periodic_freq & PF_COUNT))
158 		rtc->periodic_freq &= ~PF_COUNT;
159 	else {
160 		if (rtc->periodic_freq & PF_HP)
161 			rtc->periodic_freq |= PF_COUNT;
162 		rtc_update_irq(rtc->rtc_dev, 1, RTC_PF | RTC_IRQF);
163 	}
164 
165 	return pending;
166 }
167 
168 static irqreturn_t sh_rtc_interrupt(int irq, void *dev_id)
169 {
170 	struct sh_rtc *rtc = dev_id;
171 	int ret;
172 
173 	spin_lock(&rtc->lock);
174 	ret = __sh_rtc_interrupt(rtc);
175 	spin_unlock(&rtc->lock);
176 
177 	return IRQ_RETVAL(ret);
178 }
179 
180 static irqreturn_t sh_rtc_alarm(int irq, void *dev_id)
181 {
182 	struct sh_rtc *rtc = dev_id;
183 	int ret;
184 
185 	spin_lock(&rtc->lock);
186 	ret = __sh_rtc_alarm(rtc);
187 	spin_unlock(&rtc->lock);
188 
189 	return IRQ_RETVAL(ret);
190 }
191 
192 static irqreturn_t sh_rtc_periodic(int irq, void *dev_id)
193 {
194 	struct sh_rtc *rtc = dev_id;
195 	int ret;
196 
197 	spin_lock(&rtc->lock);
198 	ret = __sh_rtc_periodic(rtc);
199 	spin_unlock(&rtc->lock);
200 
201 	return IRQ_RETVAL(ret);
202 }
203 
204 static irqreturn_t sh_rtc_shared(int irq, void *dev_id)
205 {
206 	struct sh_rtc *rtc = dev_id;
207 	int ret;
208 
209 	spin_lock(&rtc->lock);
210 	ret = __sh_rtc_interrupt(rtc);
211 	ret |= __sh_rtc_alarm(rtc);
212 	ret |= __sh_rtc_periodic(rtc);
213 	spin_unlock(&rtc->lock);
214 
215 	return IRQ_RETVAL(ret);
216 }
217 
218 static inline void sh_rtc_setaie(struct device *dev, unsigned int enable)
219 {
220 	struct sh_rtc *rtc = dev_get_drvdata(dev);
221 	unsigned int tmp;
222 
223 	spin_lock_irq(&rtc->lock);
224 
225 	tmp = readb(rtc->regbase + RCR1);
226 
227 	if (enable)
228 		tmp |= RCR1_AIE;
229 	else
230 		tmp &= ~RCR1_AIE;
231 
232 	writeb(tmp, rtc->regbase + RCR1);
233 
234 	spin_unlock_irq(&rtc->lock);
235 }
236 
237 static int sh_rtc_proc(struct device *dev, struct seq_file *seq)
238 {
239 	struct sh_rtc *rtc = dev_get_drvdata(dev);
240 	unsigned int tmp;
241 
242 	tmp = readb(rtc->regbase + RCR1);
243 	seq_printf(seq, "carry_IRQ\t: %s\n", (tmp & RCR1_CIE) ? "yes" : "no");
244 
245 	tmp = readb(rtc->regbase + RCR2);
246 	seq_printf(seq, "periodic_IRQ\t: %s\n",
247 		   (tmp & RCR2_PESMASK) ? "yes" : "no");
248 
249 	return 0;
250 }
251 
252 static inline void sh_rtc_setcie(struct device *dev, unsigned int enable)
253 {
254 	struct sh_rtc *rtc = dev_get_drvdata(dev);
255 	unsigned int tmp;
256 
257 	spin_lock_irq(&rtc->lock);
258 
259 	tmp = readb(rtc->regbase + RCR1);
260 
261 	if (!enable)
262 		tmp &= ~RCR1_CIE;
263 	else
264 		tmp |= RCR1_CIE;
265 
266 	writeb(tmp, rtc->regbase + RCR1);
267 
268 	spin_unlock_irq(&rtc->lock);
269 }
270 
271 static int sh_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
272 {
273 	sh_rtc_setaie(dev, enabled);
274 	return 0;
275 }
276 
277 static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm)
278 {
279 	struct sh_rtc *rtc = dev_get_drvdata(dev);
280 	unsigned int sec128, sec2, yr, yr100, cf_bit;
281 
282 	do {
283 		unsigned int tmp;
284 
285 		spin_lock_irq(&rtc->lock);
286 
287 		tmp = readb(rtc->regbase + RCR1);
288 		tmp &= ~RCR1_CF; /* Clear CF-bit */
289 		tmp |= RCR1_CIE;
290 		writeb(tmp, rtc->regbase + RCR1);
291 
292 		sec128 = readb(rtc->regbase + R64CNT);
293 
294 		tm->tm_sec	= bcd2bin(readb(rtc->regbase + RSECCNT));
295 		tm->tm_min	= bcd2bin(readb(rtc->regbase + RMINCNT));
296 		tm->tm_hour	= bcd2bin(readb(rtc->regbase + RHRCNT));
297 		tm->tm_wday	= bcd2bin(readb(rtc->regbase + RWKCNT));
298 		tm->tm_mday	= bcd2bin(readb(rtc->regbase + RDAYCNT));
299 		tm->tm_mon	= bcd2bin(readb(rtc->regbase + RMONCNT)) - 1;
300 
301 		if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
302 			yr  = readw(rtc->regbase + RYRCNT);
303 			yr100 = bcd2bin(yr >> 8);
304 			yr &= 0xff;
305 		} else {
306 			yr  = readb(rtc->regbase + RYRCNT);
307 			yr100 = bcd2bin((yr == 0x99) ? 0x19 : 0x20);
308 		}
309 
310 		tm->tm_year = (yr100 * 100 + bcd2bin(yr)) - 1900;
311 
312 		sec2 = readb(rtc->regbase + R64CNT);
313 		cf_bit = readb(rtc->regbase + RCR1) & RCR1_CF;
314 
315 		spin_unlock_irq(&rtc->lock);
316 	} while (cf_bit != 0 || ((sec128 ^ sec2) & RTC_BIT_INVERTED) != 0);
317 
318 #if RTC_BIT_INVERTED != 0
319 	if ((sec128 & RTC_BIT_INVERTED))
320 		tm->tm_sec--;
321 #endif
322 
323 	/* only keep the carry interrupt enabled if UIE is on */
324 	if (!(rtc->periodic_freq & PF_OXS))
325 		sh_rtc_setcie(dev, 0);
326 
327 	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
328 		"mday=%d, mon=%d, year=%d, wday=%d\n",
329 		__func__,
330 		tm->tm_sec, tm->tm_min, tm->tm_hour,
331 		tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
332 
333 	return 0;
334 }
335 
336 static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm)
337 {
338 	struct sh_rtc *rtc = dev_get_drvdata(dev);
339 	unsigned int tmp;
340 	int year;
341 
342 	spin_lock_irq(&rtc->lock);
343 
344 	/* Reset pre-scaler & stop RTC */
345 	tmp = readb(rtc->regbase + RCR2);
346 	tmp |= RCR2_RESET;
347 	tmp &= ~RCR2_START;
348 	writeb(tmp, rtc->regbase + RCR2);
349 
350 	writeb(bin2bcd(tm->tm_sec),  rtc->regbase + RSECCNT);
351 	writeb(bin2bcd(tm->tm_min),  rtc->regbase + RMINCNT);
352 	writeb(bin2bcd(tm->tm_hour), rtc->regbase + RHRCNT);
353 	writeb(bin2bcd(tm->tm_wday), rtc->regbase + RWKCNT);
354 	writeb(bin2bcd(tm->tm_mday), rtc->regbase + RDAYCNT);
355 	writeb(bin2bcd(tm->tm_mon + 1), rtc->regbase + RMONCNT);
356 
357 	if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
358 		year = (bin2bcd((tm->tm_year + 1900) / 100) << 8) |
359 			bin2bcd(tm->tm_year % 100);
360 		writew(year, rtc->regbase + RYRCNT);
361 	} else {
362 		year = tm->tm_year % 100;
363 		writeb(bin2bcd(year), rtc->regbase + RYRCNT);
364 	}
365 
366 	/* Start RTC */
367 	tmp = readb(rtc->regbase + RCR2);
368 	tmp &= ~RCR2_RESET;
369 	tmp |= RCR2_RTCEN | RCR2_START;
370 	writeb(tmp, rtc->regbase + RCR2);
371 
372 	spin_unlock_irq(&rtc->lock);
373 
374 	return 0;
375 }
376 
377 static inline int sh_rtc_read_alarm_value(struct sh_rtc *rtc, int reg_off)
378 {
379 	unsigned int byte;
380 	int value = 0xff;	/* return 0xff for ignored values */
381 
382 	byte = readb(rtc->regbase + reg_off);
383 	if (byte & AR_ENB) {
384 		byte &= ~AR_ENB;	/* strip the enable bit */
385 		value = bcd2bin(byte);
386 	}
387 
388 	return value;
389 }
390 
391 static int sh_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
392 {
393 	struct sh_rtc *rtc = dev_get_drvdata(dev);
394 	struct rtc_time *tm = &wkalrm->time;
395 
396 	spin_lock_irq(&rtc->lock);
397 
398 	tm->tm_sec	= sh_rtc_read_alarm_value(rtc, RSECAR);
399 	tm->tm_min	= sh_rtc_read_alarm_value(rtc, RMINAR);
400 	tm->tm_hour	= sh_rtc_read_alarm_value(rtc, RHRAR);
401 	tm->tm_wday	= sh_rtc_read_alarm_value(rtc, RWKAR);
402 	tm->tm_mday	= sh_rtc_read_alarm_value(rtc, RDAYAR);
403 	tm->tm_mon	= sh_rtc_read_alarm_value(rtc, RMONAR);
404 	if (tm->tm_mon > 0)
405 		tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */
406 
407 	wkalrm->enabled = (readb(rtc->regbase + RCR1) & RCR1_AIE) ? 1 : 0;
408 
409 	spin_unlock_irq(&rtc->lock);
410 
411 	return 0;
412 }
413 
414 static inline void sh_rtc_write_alarm_value(struct sh_rtc *rtc,
415 					    int value, int reg_off)
416 {
417 	/* < 0 for a value that is ignored */
418 	if (value < 0)
419 		writeb(0, rtc->regbase + reg_off);
420 	else
421 		writeb(bin2bcd(value) | AR_ENB,  rtc->regbase + reg_off);
422 }
423 
424 static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
425 {
426 	struct sh_rtc *rtc = dev_get_drvdata(dev);
427 	unsigned int rcr1;
428 	struct rtc_time *tm = &wkalrm->time;
429 	int mon;
430 
431 	spin_lock_irq(&rtc->lock);
432 
433 	/* disable alarm interrupt and clear the alarm flag */
434 	rcr1 = readb(rtc->regbase + RCR1);
435 	rcr1 &= ~(RCR1_AF | RCR1_AIE);
436 	writeb(rcr1, rtc->regbase + RCR1);
437 
438 	/* set alarm time */
439 	sh_rtc_write_alarm_value(rtc, tm->tm_sec,  RSECAR);
440 	sh_rtc_write_alarm_value(rtc, tm->tm_min,  RMINAR);
441 	sh_rtc_write_alarm_value(rtc, tm->tm_hour, RHRAR);
442 	sh_rtc_write_alarm_value(rtc, tm->tm_wday, RWKAR);
443 	sh_rtc_write_alarm_value(rtc, tm->tm_mday, RDAYAR);
444 	mon = tm->tm_mon;
445 	if (mon >= 0)
446 		mon += 1;
447 	sh_rtc_write_alarm_value(rtc, mon, RMONAR);
448 
449 	if (wkalrm->enabled) {
450 		rcr1 |= RCR1_AIE;
451 		writeb(rcr1, rtc->regbase + RCR1);
452 	}
453 
454 	spin_unlock_irq(&rtc->lock);
455 
456 	return 0;
457 }
458 
459 static const struct rtc_class_ops sh_rtc_ops = {
460 	.read_time	= sh_rtc_read_time,
461 	.set_time	= sh_rtc_set_time,
462 	.read_alarm	= sh_rtc_read_alarm,
463 	.set_alarm	= sh_rtc_set_alarm,
464 	.proc		= sh_rtc_proc,
465 	.alarm_irq_enable = sh_rtc_alarm_irq_enable,
466 };
467 
468 static int __init sh_rtc_probe(struct platform_device *pdev)
469 {
470 	struct sh_rtc *rtc;
471 	struct resource *res;
472 	struct rtc_time r;
473 	char clk_name[6];
474 	int clk_id, ret;
475 
476 	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
477 	if (unlikely(!rtc))
478 		return -ENOMEM;
479 
480 	spin_lock_init(&rtc->lock);
481 
482 	/* get periodic/carry/alarm irqs */
483 	ret = platform_get_irq(pdev, 0);
484 	if (unlikely(ret <= 0)) {
485 		dev_err(&pdev->dev, "No IRQ resource\n");
486 		return -ENOENT;
487 	}
488 
489 	rtc->periodic_irq = ret;
490 	rtc->carry_irq = platform_get_irq(pdev, 1);
491 	rtc->alarm_irq = platform_get_irq(pdev, 2);
492 
493 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
494 	if (!res)
495 		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
496 	if (unlikely(res == NULL)) {
497 		dev_err(&pdev->dev, "No IO resource\n");
498 		return -ENOENT;
499 	}
500 
501 	rtc->regsize = resource_size(res);
502 
503 	rtc->res = devm_request_mem_region(&pdev->dev, res->start,
504 					rtc->regsize, pdev->name);
505 	if (unlikely(!rtc->res))
506 		return -EBUSY;
507 
508 	rtc->regbase = devm_ioremap_nocache(&pdev->dev, rtc->res->start,
509 					rtc->regsize);
510 	if (unlikely(!rtc->regbase))
511 		return -EINVAL;
512 
513 	if (!pdev->dev.of_node) {
514 		clk_id = pdev->id;
515 		/* With a single device, the clock id is still "rtc0" */
516 		if (clk_id < 0)
517 			clk_id = 0;
518 
519 		snprintf(clk_name, sizeof(clk_name), "rtc%d", clk_id);
520 	} else
521 		snprintf(clk_name, sizeof(clk_name), "fck");
522 
523 	rtc->clk = devm_clk_get(&pdev->dev, clk_name);
524 	if (IS_ERR(rtc->clk)) {
525 		/*
526 		 * No error handling for rtc->clk intentionally, not all
527 		 * platforms will have a unique clock for the RTC, and
528 		 * the clk API can handle the struct clk pointer being
529 		 * NULL.
530 		 */
531 		rtc->clk = NULL;
532 	}
533 
534 	clk_enable(rtc->clk);
535 
536 	rtc->capabilities = RTC_DEF_CAPABILITIES;
537 
538 #ifdef CONFIG_SUPERH
539 	if (dev_get_platdata(&pdev->dev)) {
540 		struct sh_rtc_platform_info *pinfo =
541 			dev_get_platdata(&pdev->dev);
542 
543 		/*
544 		 * Some CPUs have special capabilities in addition to the
545 		 * default set. Add those in here.
546 		 */
547 		rtc->capabilities |= pinfo->capabilities;
548 	}
549 #endif
550 
551 	if (rtc->carry_irq <= 0) {
552 		/* register shared periodic/carry/alarm irq */
553 		ret = devm_request_irq(&pdev->dev, rtc->periodic_irq,
554 				sh_rtc_shared, 0, "sh-rtc", rtc);
555 		if (unlikely(ret)) {
556 			dev_err(&pdev->dev,
557 				"request IRQ failed with %d, IRQ %d\n", ret,
558 				rtc->periodic_irq);
559 			goto err_unmap;
560 		}
561 	} else {
562 		/* register periodic/carry/alarm irqs */
563 		ret = devm_request_irq(&pdev->dev, rtc->periodic_irq,
564 				sh_rtc_periodic, 0, "sh-rtc period", rtc);
565 		if (unlikely(ret)) {
566 			dev_err(&pdev->dev,
567 				"request period IRQ failed with %d, IRQ %d\n",
568 				ret, rtc->periodic_irq);
569 			goto err_unmap;
570 		}
571 
572 		ret = devm_request_irq(&pdev->dev, rtc->carry_irq,
573 				sh_rtc_interrupt, 0, "sh-rtc carry", rtc);
574 		if (unlikely(ret)) {
575 			dev_err(&pdev->dev,
576 				"request carry IRQ failed with %d, IRQ %d\n",
577 				ret, rtc->carry_irq);
578 			goto err_unmap;
579 		}
580 
581 		ret = devm_request_irq(&pdev->dev, rtc->alarm_irq,
582 				sh_rtc_alarm, 0, "sh-rtc alarm", rtc);
583 		if (unlikely(ret)) {
584 			dev_err(&pdev->dev,
585 				"request alarm IRQ failed with %d, IRQ %d\n",
586 				ret, rtc->alarm_irq);
587 			goto err_unmap;
588 		}
589 	}
590 
591 	platform_set_drvdata(pdev, rtc);
592 
593 	/* everything disabled by default */
594 	sh_rtc_setaie(&pdev->dev, 0);
595 	sh_rtc_setcie(&pdev->dev, 0);
596 
597 	rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "sh",
598 					   &sh_rtc_ops, THIS_MODULE);
599 	if (IS_ERR(rtc->rtc_dev)) {
600 		ret = PTR_ERR(rtc->rtc_dev);
601 		goto err_unmap;
602 	}
603 
604 	rtc->rtc_dev->max_user_freq = 256;
605 
606 	/* reset rtc to epoch 0 if time is invalid */
607 	if (rtc_read_time(rtc->rtc_dev, &r) < 0) {
608 		rtc_time_to_tm(0, &r);
609 		rtc_set_time(rtc->rtc_dev, &r);
610 	}
611 
612 	device_init_wakeup(&pdev->dev, 1);
613 	return 0;
614 
615 err_unmap:
616 	clk_disable(rtc->clk);
617 
618 	return ret;
619 }
620 
621 static int __exit sh_rtc_remove(struct platform_device *pdev)
622 {
623 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
624 
625 	sh_rtc_setaie(&pdev->dev, 0);
626 	sh_rtc_setcie(&pdev->dev, 0);
627 
628 	clk_disable(rtc->clk);
629 
630 	return 0;
631 }
632 
633 static void sh_rtc_set_irq_wake(struct device *dev, int enabled)
634 {
635 	struct sh_rtc *rtc = dev_get_drvdata(dev);
636 
637 	irq_set_irq_wake(rtc->periodic_irq, enabled);
638 
639 	if (rtc->carry_irq > 0) {
640 		irq_set_irq_wake(rtc->carry_irq, enabled);
641 		irq_set_irq_wake(rtc->alarm_irq, enabled);
642 	}
643 }
644 
645 static int __maybe_unused sh_rtc_suspend(struct device *dev)
646 {
647 	if (device_may_wakeup(dev))
648 		sh_rtc_set_irq_wake(dev, 1);
649 
650 	return 0;
651 }
652 
653 static int __maybe_unused sh_rtc_resume(struct device *dev)
654 {
655 	if (device_may_wakeup(dev))
656 		sh_rtc_set_irq_wake(dev, 0);
657 
658 	return 0;
659 }
660 
661 static SIMPLE_DEV_PM_OPS(sh_rtc_pm_ops, sh_rtc_suspend, sh_rtc_resume);
662 
663 static const struct of_device_id sh_rtc_of_match[] = {
664 	{ .compatible = "renesas,sh-rtc", },
665 	{ /* sentinel */ }
666 };
667 MODULE_DEVICE_TABLE(of, sh_rtc_of_match);
668 
669 static struct platform_driver sh_rtc_platform_driver = {
670 	.driver		= {
671 		.name	= DRV_NAME,
672 		.pm	= &sh_rtc_pm_ops,
673 		.of_match_table = sh_rtc_of_match,
674 	},
675 	.remove		= __exit_p(sh_rtc_remove),
676 };
677 
678 module_platform_driver_probe(sh_rtc_platform_driver, sh_rtc_probe);
679 
680 MODULE_DESCRIPTION("SuperH on-chip RTC driver");
681 MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, "
682 	      "Jamie Lenehan <lenehan@twibble.org>, "
683 	      "Angelo Castello <angelo.castello@st.com>");
684 MODULE_LICENSE("GPL");
685 MODULE_ALIAS("platform:" DRV_NAME);
686