xref: /openbmc/linux/drivers/rtc/rtc-sh.c (revision d003d772)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * SuperH On-Chip RTC Support
4  *
5  * Copyright (C) 2006 - 2009  Paul Mundt
6  * Copyright (C) 2006  Jamie Lenehan
7  * Copyright (C) 2008  Angelo Castello
8  *
9  * Based on the old arch/sh/kernel/cpu/rtc.c by:
10  *
11  *  Copyright (C) 2000  Philipp Rumpf <prumpf@tux.org>
12  *  Copyright (C) 1999  Tetsuya Okada & Niibe Yutaka
13  */
14 #include <linux/module.h>
15 #include <linux/mod_devicetable.h>
16 #include <linux/kernel.h>
17 #include <linux/bcd.h>
18 #include <linux/rtc.h>
19 #include <linux/init.h>
20 #include <linux/platform_device.h>
21 #include <linux/seq_file.h>
22 #include <linux/interrupt.h>
23 #include <linux/spinlock.h>
24 #include <linux/io.h>
25 #include <linux/log2.h>
26 #include <linux/clk.h>
27 #include <linux/slab.h>
28 #ifdef CONFIG_SUPERH
29 #include <asm/rtc.h>
30 #else
31 /* Default values for RZ/A RTC */
32 #define rtc_reg_size		sizeof(u16)
33 #define RTC_BIT_INVERTED        0	/* no chip bugs */
34 #define RTC_CAP_4_DIGIT_YEAR    (1 << 0)
35 #define RTC_DEF_CAPABILITIES    RTC_CAP_4_DIGIT_YEAR
36 #endif
37 
38 #define DRV_NAME	"sh-rtc"
39 
40 #define RTC_REG(r)	((r) * rtc_reg_size)
41 
42 #define R64CNT		RTC_REG(0)
43 
44 #define RSECCNT		RTC_REG(1)	/* RTC sec */
45 #define RMINCNT		RTC_REG(2)	/* RTC min */
46 #define RHRCNT		RTC_REG(3)	/* RTC hour */
47 #define RWKCNT		RTC_REG(4)	/* RTC week */
48 #define RDAYCNT		RTC_REG(5)	/* RTC day */
49 #define RMONCNT		RTC_REG(6)	/* RTC month */
50 #define RYRCNT		RTC_REG(7)	/* RTC year */
51 #define RSECAR		RTC_REG(8)	/* ALARM sec */
52 #define RMINAR		RTC_REG(9)	/* ALARM min */
53 #define RHRAR		RTC_REG(10)	/* ALARM hour */
54 #define RWKAR		RTC_REG(11)	/* ALARM week */
55 #define RDAYAR		RTC_REG(12)	/* ALARM day */
56 #define RMONAR		RTC_REG(13)	/* ALARM month */
57 #define RCR1		RTC_REG(14)	/* Control */
58 #define RCR2		RTC_REG(15)	/* Control */
59 
60 /*
61  * Note on RYRAR and RCR3: Up until this point most of the register
62  * definitions are consistent across all of the available parts. However,
63  * the placement of the optional RYRAR and RCR3 (the RYRAR control
64  * register used to control RYRCNT/RYRAR compare) varies considerably
65  * across various parts, occasionally being mapped in to a completely
66  * unrelated address space. For proper RYRAR support a separate resource
67  * would have to be handed off, but as this is purely optional in
68  * practice, we simply opt not to support it, thereby keeping the code
69  * quite a bit more simplified.
70  */
71 
72 /* ALARM Bits - or with BCD encoded value */
73 #define AR_ENB		0x80	/* Enable for alarm cmp   */
74 
75 /* Period Bits */
76 #define PF_HP		0x100	/* Enable Half Period to support 8,32,128Hz */
77 #define PF_COUNT	0x200	/* Half periodic counter */
78 #define PF_OXS		0x400	/* Periodic One x Second */
79 #define PF_KOU		0x800	/* Kernel or User periodic request 1=kernel */
80 #define PF_MASK		0xf00
81 
82 /* RCR1 Bits */
83 #define RCR1_CF		0x80	/* Carry Flag             */
84 #define RCR1_CIE	0x10	/* Carry Interrupt Enable */
85 #define RCR1_AIE	0x08	/* Alarm Interrupt Enable */
86 #define RCR1_AF		0x01	/* Alarm Flag             */
87 
88 /* RCR2 Bits */
89 #define RCR2_PEF	0x80	/* PEriodic interrupt Flag */
90 #define RCR2_PESMASK	0x70	/* Periodic interrupt Set  */
91 #define RCR2_RTCEN	0x08	/* ENable RTC              */
92 #define RCR2_ADJ	0x04	/* ADJustment (30-second)  */
93 #define RCR2_RESET	0x02	/* Reset bit               */
94 #define RCR2_START	0x01	/* Start bit               */
95 
96 struct sh_rtc {
97 	void __iomem		*regbase;
98 	unsigned long		regsize;
99 	struct resource		*res;
100 	int			alarm_irq;
101 	int			periodic_irq;
102 	int			carry_irq;
103 	struct clk		*clk;
104 	struct rtc_device	*rtc_dev;
105 	spinlock_t		lock;
106 	unsigned long		capabilities;	/* See asm/rtc.h for cap bits */
107 	unsigned short		periodic_freq;
108 };
109 
110 static int __sh_rtc_interrupt(struct sh_rtc *rtc)
111 {
112 	unsigned int tmp, pending;
113 
114 	tmp = readb(rtc->regbase + RCR1);
115 	pending = tmp & RCR1_CF;
116 	tmp &= ~RCR1_CF;
117 	writeb(tmp, rtc->regbase + RCR1);
118 
119 	/* Users have requested One x Second IRQ */
120 	if (pending && rtc->periodic_freq & PF_OXS)
121 		rtc_update_irq(rtc->rtc_dev, 1, RTC_UF | RTC_IRQF);
122 
123 	return pending;
124 }
125 
126 static int __sh_rtc_alarm(struct sh_rtc *rtc)
127 {
128 	unsigned int tmp, pending;
129 
130 	tmp = readb(rtc->regbase + RCR1);
131 	pending = tmp & RCR1_AF;
132 	tmp &= ~(RCR1_AF | RCR1_AIE);
133 	writeb(tmp, rtc->regbase + RCR1);
134 
135 	if (pending)
136 		rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF);
137 
138 	return pending;
139 }
140 
141 static int __sh_rtc_periodic(struct sh_rtc *rtc)
142 {
143 	unsigned int tmp, pending;
144 
145 	tmp = readb(rtc->regbase + RCR2);
146 	pending = tmp & RCR2_PEF;
147 	tmp &= ~RCR2_PEF;
148 	writeb(tmp, rtc->regbase + RCR2);
149 
150 	if (!pending)
151 		return 0;
152 
153 	/* Half period enabled than one skipped and the next notified */
154 	if ((rtc->periodic_freq & PF_HP) && (rtc->periodic_freq & PF_COUNT))
155 		rtc->periodic_freq &= ~PF_COUNT;
156 	else {
157 		if (rtc->periodic_freq & PF_HP)
158 			rtc->periodic_freq |= PF_COUNT;
159 		rtc_update_irq(rtc->rtc_dev, 1, RTC_PF | RTC_IRQF);
160 	}
161 
162 	return pending;
163 }
164 
165 static irqreturn_t sh_rtc_interrupt(int irq, void *dev_id)
166 {
167 	struct sh_rtc *rtc = dev_id;
168 	int ret;
169 
170 	spin_lock(&rtc->lock);
171 	ret = __sh_rtc_interrupt(rtc);
172 	spin_unlock(&rtc->lock);
173 
174 	return IRQ_RETVAL(ret);
175 }
176 
177 static irqreturn_t sh_rtc_alarm(int irq, void *dev_id)
178 {
179 	struct sh_rtc *rtc = dev_id;
180 	int ret;
181 
182 	spin_lock(&rtc->lock);
183 	ret = __sh_rtc_alarm(rtc);
184 	spin_unlock(&rtc->lock);
185 
186 	return IRQ_RETVAL(ret);
187 }
188 
189 static irqreturn_t sh_rtc_periodic(int irq, void *dev_id)
190 {
191 	struct sh_rtc *rtc = dev_id;
192 	int ret;
193 
194 	spin_lock(&rtc->lock);
195 	ret = __sh_rtc_periodic(rtc);
196 	spin_unlock(&rtc->lock);
197 
198 	return IRQ_RETVAL(ret);
199 }
200 
201 static irqreturn_t sh_rtc_shared(int irq, void *dev_id)
202 {
203 	struct sh_rtc *rtc = dev_id;
204 	int ret;
205 
206 	spin_lock(&rtc->lock);
207 	ret = __sh_rtc_interrupt(rtc);
208 	ret |= __sh_rtc_alarm(rtc);
209 	ret |= __sh_rtc_periodic(rtc);
210 	spin_unlock(&rtc->lock);
211 
212 	return IRQ_RETVAL(ret);
213 }
214 
215 static inline void sh_rtc_setaie(struct device *dev, unsigned int enable)
216 {
217 	struct sh_rtc *rtc = dev_get_drvdata(dev);
218 	unsigned int tmp;
219 
220 	spin_lock_irq(&rtc->lock);
221 
222 	tmp = readb(rtc->regbase + RCR1);
223 
224 	if (enable)
225 		tmp |= RCR1_AIE;
226 	else
227 		tmp &= ~RCR1_AIE;
228 
229 	writeb(tmp, rtc->regbase + RCR1);
230 
231 	spin_unlock_irq(&rtc->lock);
232 }
233 
234 static int sh_rtc_proc(struct device *dev, struct seq_file *seq)
235 {
236 	struct sh_rtc *rtc = dev_get_drvdata(dev);
237 	unsigned int tmp;
238 
239 	tmp = readb(rtc->regbase + RCR1);
240 	seq_printf(seq, "carry_IRQ\t: %s\n", (tmp & RCR1_CIE) ? "yes" : "no");
241 
242 	tmp = readb(rtc->regbase + RCR2);
243 	seq_printf(seq, "periodic_IRQ\t: %s\n",
244 		   (tmp & RCR2_PESMASK) ? "yes" : "no");
245 
246 	return 0;
247 }
248 
249 static inline void sh_rtc_setcie(struct device *dev, unsigned int enable)
250 {
251 	struct sh_rtc *rtc = dev_get_drvdata(dev);
252 	unsigned int tmp;
253 
254 	spin_lock_irq(&rtc->lock);
255 
256 	tmp = readb(rtc->regbase + RCR1);
257 
258 	if (!enable)
259 		tmp &= ~RCR1_CIE;
260 	else
261 		tmp |= RCR1_CIE;
262 
263 	writeb(tmp, rtc->regbase + RCR1);
264 
265 	spin_unlock_irq(&rtc->lock);
266 }
267 
268 static int sh_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
269 {
270 	sh_rtc_setaie(dev, enabled);
271 	return 0;
272 }
273 
274 static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm)
275 {
276 	struct sh_rtc *rtc = dev_get_drvdata(dev);
277 	unsigned int sec128, sec2, yr, yr100, cf_bit;
278 
279 	do {
280 		unsigned int tmp;
281 
282 		spin_lock_irq(&rtc->lock);
283 
284 		tmp = readb(rtc->regbase + RCR1);
285 		tmp &= ~RCR1_CF; /* Clear CF-bit */
286 		tmp |= RCR1_CIE;
287 		writeb(tmp, rtc->regbase + RCR1);
288 
289 		sec128 = readb(rtc->regbase + R64CNT);
290 
291 		tm->tm_sec	= bcd2bin(readb(rtc->regbase + RSECCNT));
292 		tm->tm_min	= bcd2bin(readb(rtc->regbase + RMINCNT));
293 		tm->tm_hour	= bcd2bin(readb(rtc->regbase + RHRCNT));
294 		tm->tm_wday	= bcd2bin(readb(rtc->regbase + RWKCNT));
295 		tm->tm_mday	= bcd2bin(readb(rtc->regbase + RDAYCNT));
296 		tm->tm_mon	= bcd2bin(readb(rtc->regbase + RMONCNT)) - 1;
297 
298 		if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
299 			yr  = readw(rtc->regbase + RYRCNT);
300 			yr100 = bcd2bin(yr >> 8);
301 			yr &= 0xff;
302 		} else {
303 			yr  = readb(rtc->regbase + RYRCNT);
304 			yr100 = bcd2bin((yr == 0x99) ? 0x19 : 0x20);
305 		}
306 
307 		tm->tm_year = (yr100 * 100 + bcd2bin(yr)) - 1900;
308 
309 		sec2 = readb(rtc->regbase + R64CNT);
310 		cf_bit = readb(rtc->regbase + RCR1) & RCR1_CF;
311 
312 		spin_unlock_irq(&rtc->lock);
313 	} while (cf_bit != 0 || ((sec128 ^ sec2) & RTC_BIT_INVERTED) != 0);
314 
315 #if RTC_BIT_INVERTED != 0
316 	if ((sec128 & RTC_BIT_INVERTED))
317 		tm->tm_sec--;
318 #endif
319 
320 	/* only keep the carry interrupt enabled if UIE is on */
321 	if (!(rtc->periodic_freq & PF_OXS))
322 		sh_rtc_setcie(dev, 0);
323 
324 	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
325 		"mday=%d, mon=%d, year=%d, wday=%d\n",
326 		__func__,
327 		tm->tm_sec, tm->tm_min, tm->tm_hour,
328 		tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
329 
330 	return 0;
331 }
332 
333 static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm)
334 {
335 	struct sh_rtc *rtc = dev_get_drvdata(dev);
336 	unsigned int tmp;
337 	int year;
338 
339 	spin_lock_irq(&rtc->lock);
340 
341 	/* Reset pre-scaler & stop RTC */
342 	tmp = readb(rtc->regbase + RCR2);
343 	tmp |= RCR2_RESET;
344 	tmp &= ~RCR2_START;
345 	writeb(tmp, rtc->regbase + RCR2);
346 
347 	writeb(bin2bcd(tm->tm_sec),  rtc->regbase + RSECCNT);
348 	writeb(bin2bcd(tm->tm_min),  rtc->regbase + RMINCNT);
349 	writeb(bin2bcd(tm->tm_hour), rtc->regbase + RHRCNT);
350 	writeb(bin2bcd(tm->tm_wday), rtc->regbase + RWKCNT);
351 	writeb(bin2bcd(tm->tm_mday), rtc->regbase + RDAYCNT);
352 	writeb(bin2bcd(tm->tm_mon + 1), rtc->regbase + RMONCNT);
353 
354 	if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
355 		year = (bin2bcd((tm->tm_year + 1900) / 100) << 8) |
356 			bin2bcd(tm->tm_year % 100);
357 		writew(year, rtc->regbase + RYRCNT);
358 	} else {
359 		year = tm->tm_year % 100;
360 		writeb(bin2bcd(year), rtc->regbase + RYRCNT);
361 	}
362 
363 	/* Start RTC */
364 	tmp = readb(rtc->regbase + RCR2);
365 	tmp &= ~RCR2_RESET;
366 	tmp |= RCR2_RTCEN | RCR2_START;
367 	writeb(tmp, rtc->regbase + RCR2);
368 
369 	spin_unlock_irq(&rtc->lock);
370 
371 	return 0;
372 }
373 
374 static inline int sh_rtc_read_alarm_value(struct sh_rtc *rtc, int reg_off)
375 {
376 	unsigned int byte;
377 	int value = -1;			/* return -1 for ignored values */
378 
379 	byte = readb(rtc->regbase + reg_off);
380 	if (byte & AR_ENB) {
381 		byte &= ~AR_ENB;	/* strip the enable bit */
382 		value = bcd2bin(byte);
383 	}
384 
385 	return value;
386 }
387 
388 static int sh_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
389 {
390 	struct sh_rtc *rtc = dev_get_drvdata(dev);
391 	struct rtc_time *tm = &wkalrm->time;
392 
393 	spin_lock_irq(&rtc->lock);
394 
395 	tm->tm_sec	= sh_rtc_read_alarm_value(rtc, RSECAR);
396 	tm->tm_min	= sh_rtc_read_alarm_value(rtc, RMINAR);
397 	tm->tm_hour	= sh_rtc_read_alarm_value(rtc, RHRAR);
398 	tm->tm_wday	= sh_rtc_read_alarm_value(rtc, RWKAR);
399 	tm->tm_mday	= sh_rtc_read_alarm_value(rtc, RDAYAR);
400 	tm->tm_mon	= sh_rtc_read_alarm_value(rtc, RMONAR);
401 	if (tm->tm_mon > 0)
402 		tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */
403 
404 	wkalrm->enabled = (readb(rtc->regbase + RCR1) & RCR1_AIE) ? 1 : 0;
405 
406 	spin_unlock_irq(&rtc->lock);
407 
408 	return 0;
409 }
410 
411 static inline void sh_rtc_write_alarm_value(struct sh_rtc *rtc,
412 					    int value, int reg_off)
413 {
414 	/* < 0 for a value that is ignored */
415 	if (value < 0)
416 		writeb(0, rtc->regbase + reg_off);
417 	else
418 		writeb(bin2bcd(value) | AR_ENB,  rtc->regbase + reg_off);
419 }
420 
421 static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
422 {
423 	struct sh_rtc *rtc = dev_get_drvdata(dev);
424 	unsigned int rcr1;
425 	struct rtc_time *tm = &wkalrm->time;
426 	int mon;
427 
428 	spin_lock_irq(&rtc->lock);
429 
430 	/* disable alarm interrupt and clear the alarm flag */
431 	rcr1 = readb(rtc->regbase + RCR1);
432 	rcr1 &= ~(RCR1_AF | RCR1_AIE);
433 	writeb(rcr1, rtc->regbase + RCR1);
434 
435 	/* set alarm time */
436 	sh_rtc_write_alarm_value(rtc, tm->tm_sec,  RSECAR);
437 	sh_rtc_write_alarm_value(rtc, tm->tm_min,  RMINAR);
438 	sh_rtc_write_alarm_value(rtc, tm->tm_hour, RHRAR);
439 	sh_rtc_write_alarm_value(rtc, tm->tm_wday, RWKAR);
440 	sh_rtc_write_alarm_value(rtc, tm->tm_mday, RDAYAR);
441 	mon = tm->tm_mon;
442 	if (mon >= 0)
443 		mon += 1;
444 	sh_rtc_write_alarm_value(rtc, mon, RMONAR);
445 
446 	if (wkalrm->enabled) {
447 		rcr1 |= RCR1_AIE;
448 		writeb(rcr1, rtc->regbase + RCR1);
449 	}
450 
451 	spin_unlock_irq(&rtc->lock);
452 
453 	return 0;
454 }
455 
456 static const struct rtc_class_ops sh_rtc_ops = {
457 	.read_time	= sh_rtc_read_time,
458 	.set_time	= sh_rtc_set_time,
459 	.read_alarm	= sh_rtc_read_alarm,
460 	.set_alarm	= sh_rtc_set_alarm,
461 	.proc		= sh_rtc_proc,
462 	.alarm_irq_enable = sh_rtc_alarm_irq_enable,
463 };
464 
465 static int __init sh_rtc_probe(struct platform_device *pdev)
466 {
467 	struct sh_rtc *rtc;
468 	struct resource *res;
469 	struct rtc_time r;
470 	char clk_name[6];
471 	int clk_id, ret;
472 
473 	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
474 	if (unlikely(!rtc))
475 		return -ENOMEM;
476 
477 	spin_lock_init(&rtc->lock);
478 
479 	/* get periodic/carry/alarm irqs */
480 	ret = platform_get_irq(pdev, 0);
481 	if (unlikely(ret <= 0)) {
482 		dev_err(&pdev->dev, "No IRQ resource\n");
483 		return -ENOENT;
484 	}
485 
486 	rtc->periodic_irq = ret;
487 	rtc->carry_irq = platform_get_irq(pdev, 1);
488 	rtc->alarm_irq = platform_get_irq(pdev, 2);
489 
490 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
491 	if (!res)
492 		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
493 	if (unlikely(res == NULL)) {
494 		dev_err(&pdev->dev, "No IO resource\n");
495 		return -ENOENT;
496 	}
497 
498 	rtc->regsize = resource_size(res);
499 
500 	rtc->res = devm_request_mem_region(&pdev->dev, res->start,
501 					rtc->regsize, pdev->name);
502 	if (unlikely(!rtc->res))
503 		return -EBUSY;
504 
505 	rtc->regbase = devm_ioremap_nocache(&pdev->dev, rtc->res->start,
506 					rtc->regsize);
507 	if (unlikely(!rtc->regbase))
508 		return -EINVAL;
509 
510 	if (!pdev->dev.of_node) {
511 		clk_id = pdev->id;
512 		/* With a single device, the clock id is still "rtc0" */
513 		if (clk_id < 0)
514 			clk_id = 0;
515 
516 		snprintf(clk_name, sizeof(clk_name), "rtc%d", clk_id);
517 	} else
518 		snprintf(clk_name, sizeof(clk_name), "fck");
519 
520 	rtc->clk = devm_clk_get(&pdev->dev, clk_name);
521 	if (IS_ERR(rtc->clk)) {
522 		/*
523 		 * No error handling for rtc->clk intentionally, not all
524 		 * platforms will have a unique clock for the RTC, and
525 		 * the clk API can handle the struct clk pointer being
526 		 * NULL.
527 		 */
528 		rtc->clk = NULL;
529 	}
530 
531 	clk_enable(rtc->clk);
532 
533 	rtc->capabilities = RTC_DEF_CAPABILITIES;
534 
535 #ifdef CONFIG_SUPERH
536 	if (dev_get_platdata(&pdev->dev)) {
537 		struct sh_rtc_platform_info *pinfo =
538 			dev_get_platdata(&pdev->dev);
539 
540 		/*
541 		 * Some CPUs have special capabilities in addition to the
542 		 * default set. Add those in here.
543 		 */
544 		rtc->capabilities |= pinfo->capabilities;
545 	}
546 #endif
547 
548 	if (rtc->carry_irq <= 0) {
549 		/* register shared periodic/carry/alarm irq */
550 		ret = devm_request_irq(&pdev->dev, rtc->periodic_irq,
551 				sh_rtc_shared, 0, "sh-rtc", rtc);
552 		if (unlikely(ret)) {
553 			dev_err(&pdev->dev,
554 				"request IRQ failed with %d, IRQ %d\n", ret,
555 				rtc->periodic_irq);
556 			goto err_unmap;
557 		}
558 	} else {
559 		/* register periodic/carry/alarm irqs */
560 		ret = devm_request_irq(&pdev->dev, rtc->periodic_irq,
561 				sh_rtc_periodic, 0, "sh-rtc period", rtc);
562 		if (unlikely(ret)) {
563 			dev_err(&pdev->dev,
564 				"request period IRQ failed with %d, IRQ %d\n",
565 				ret, rtc->periodic_irq);
566 			goto err_unmap;
567 		}
568 
569 		ret = devm_request_irq(&pdev->dev, rtc->carry_irq,
570 				sh_rtc_interrupt, 0, "sh-rtc carry", rtc);
571 		if (unlikely(ret)) {
572 			dev_err(&pdev->dev,
573 				"request carry IRQ failed with %d, IRQ %d\n",
574 				ret, rtc->carry_irq);
575 			goto err_unmap;
576 		}
577 
578 		ret = devm_request_irq(&pdev->dev, rtc->alarm_irq,
579 				sh_rtc_alarm, 0, "sh-rtc alarm", rtc);
580 		if (unlikely(ret)) {
581 			dev_err(&pdev->dev,
582 				"request alarm IRQ failed with %d, IRQ %d\n",
583 				ret, rtc->alarm_irq);
584 			goto err_unmap;
585 		}
586 	}
587 
588 	platform_set_drvdata(pdev, rtc);
589 
590 	/* everything disabled by default */
591 	sh_rtc_setaie(&pdev->dev, 0);
592 	sh_rtc_setcie(&pdev->dev, 0);
593 
594 	rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "sh",
595 					   &sh_rtc_ops, THIS_MODULE);
596 	if (IS_ERR(rtc->rtc_dev)) {
597 		ret = PTR_ERR(rtc->rtc_dev);
598 		goto err_unmap;
599 	}
600 
601 	rtc->rtc_dev->max_user_freq = 256;
602 
603 	/* reset rtc to epoch 0 if time is invalid */
604 	if (rtc_read_time(rtc->rtc_dev, &r) < 0) {
605 		rtc_time_to_tm(0, &r);
606 		rtc_set_time(rtc->rtc_dev, &r);
607 	}
608 
609 	device_init_wakeup(&pdev->dev, 1);
610 	return 0;
611 
612 err_unmap:
613 	clk_disable(rtc->clk);
614 
615 	return ret;
616 }
617 
618 static int __exit sh_rtc_remove(struct platform_device *pdev)
619 {
620 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
621 
622 	sh_rtc_setaie(&pdev->dev, 0);
623 	sh_rtc_setcie(&pdev->dev, 0);
624 
625 	clk_disable(rtc->clk);
626 
627 	return 0;
628 }
629 
630 static void sh_rtc_set_irq_wake(struct device *dev, int enabled)
631 {
632 	struct sh_rtc *rtc = dev_get_drvdata(dev);
633 
634 	irq_set_irq_wake(rtc->periodic_irq, enabled);
635 
636 	if (rtc->carry_irq > 0) {
637 		irq_set_irq_wake(rtc->carry_irq, enabled);
638 		irq_set_irq_wake(rtc->alarm_irq, enabled);
639 	}
640 }
641 
642 static int __maybe_unused sh_rtc_suspend(struct device *dev)
643 {
644 	if (device_may_wakeup(dev))
645 		sh_rtc_set_irq_wake(dev, 1);
646 
647 	return 0;
648 }
649 
650 static int __maybe_unused sh_rtc_resume(struct device *dev)
651 {
652 	if (device_may_wakeup(dev))
653 		sh_rtc_set_irq_wake(dev, 0);
654 
655 	return 0;
656 }
657 
658 static SIMPLE_DEV_PM_OPS(sh_rtc_pm_ops, sh_rtc_suspend, sh_rtc_resume);
659 
660 static const struct of_device_id sh_rtc_of_match[] = {
661 	{ .compatible = "renesas,sh-rtc", },
662 	{ /* sentinel */ }
663 };
664 MODULE_DEVICE_TABLE(of, sh_rtc_of_match);
665 
666 static struct platform_driver sh_rtc_platform_driver = {
667 	.driver		= {
668 		.name	= DRV_NAME,
669 		.pm	= &sh_rtc_pm_ops,
670 		.of_match_table = sh_rtc_of_match,
671 	},
672 	.remove		= __exit_p(sh_rtc_remove),
673 };
674 
675 module_platform_driver_probe(sh_rtc_platform_driver, sh_rtc_probe);
676 
677 MODULE_DESCRIPTION("SuperH on-chip RTC driver");
678 MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, "
679 	      "Jamie Lenehan <lenehan@twibble.org>, "
680 	      "Angelo Castello <angelo.castello@st.com>");
681 MODULE_LICENSE("GPL v2");
682 MODULE_ALIAS("platform:" DRV_NAME);
683