xref: /openbmc/linux/drivers/rtc/rtc-sh.c (revision 77d84ff8)
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/kernel.h>
19 #include <linux/bcd.h>
20 #include <linux/rtc.h>
21 #include <linux/init.h>
22 #include <linux/platform_device.h>
23 #include <linux/seq_file.h>
24 #include <linux/interrupt.h>
25 #include <linux/spinlock.h>
26 #include <linux/io.h>
27 #include <linux/log2.h>
28 #include <linux/clk.h>
29 #include <linux/slab.h>
30 #include <asm/rtc.h>
31 
32 #define DRV_NAME	"sh-rtc"
33 #define DRV_VERSION	"0.2.3"
34 
35 #define RTC_REG(r)	((r) * rtc_reg_size)
36 
37 #define R64CNT		RTC_REG(0)
38 
39 #define RSECCNT		RTC_REG(1)	/* RTC sec */
40 #define RMINCNT		RTC_REG(2)	/* RTC min */
41 #define RHRCNT		RTC_REG(3)	/* RTC hour */
42 #define RWKCNT		RTC_REG(4)	/* RTC week */
43 #define RDAYCNT		RTC_REG(5)	/* RTC day */
44 #define RMONCNT		RTC_REG(6)	/* RTC month */
45 #define RYRCNT		RTC_REG(7)	/* RTC year */
46 #define RSECAR		RTC_REG(8)	/* ALARM sec */
47 #define RMINAR		RTC_REG(9)	/* ALARM min */
48 #define RHRAR		RTC_REG(10)	/* ALARM hour */
49 #define RWKAR		RTC_REG(11)	/* ALARM week */
50 #define RDAYAR		RTC_REG(12)	/* ALARM day */
51 #define RMONAR		RTC_REG(13)	/* ALARM month */
52 #define RCR1		RTC_REG(14)	/* Control */
53 #define RCR2		RTC_REG(15)	/* Control */
54 
55 /*
56  * Note on RYRAR and RCR3: Up until this point most of the register
57  * definitions are consistent across all of the available parts. However,
58  * the placement of the optional RYRAR and RCR3 (the RYRAR control
59  * register used to control RYRCNT/RYRAR compare) varies considerably
60  * across various parts, occasionally being mapped in to a completely
61  * unrelated address space. For proper RYRAR support a separate resource
62  * would have to be handed off, but as this is purely optional in
63  * practice, we simply opt not to support it, thereby keeping the code
64  * quite a bit more simplified.
65  */
66 
67 /* ALARM Bits - or with BCD encoded value */
68 #define AR_ENB		0x80	/* Enable for alarm cmp   */
69 
70 /* Period Bits */
71 #define PF_HP		0x100	/* Enable Half Period to support 8,32,128Hz */
72 #define PF_COUNT	0x200	/* Half periodic counter */
73 #define PF_OXS		0x400	/* Periodic One x Second */
74 #define PF_KOU		0x800	/* Kernel or User periodic request 1=kernel */
75 #define PF_MASK		0xf00
76 
77 /* RCR1 Bits */
78 #define RCR1_CF		0x80	/* Carry Flag             */
79 #define RCR1_CIE	0x10	/* Carry Interrupt Enable */
80 #define RCR1_AIE	0x08	/* Alarm Interrupt Enable */
81 #define RCR1_AF		0x01	/* Alarm Flag             */
82 
83 /* RCR2 Bits */
84 #define RCR2_PEF	0x80	/* PEriodic interrupt Flag */
85 #define RCR2_PESMASK	0x70	/* Periodic interrupt Set  */
86 #define RCR2_RTCEN	0x08	/* ENable RTC              */
87 #define RCR2_ADJ	0x04	/* ADJustment (30-second)  */
88 #define RCR2_RESET	0x02	/* Reset bit               */
89 #define RCR2_START	0x01	/* Start bit               */
90 
91 struct sh_rtc {
92 	void __iomem		*regbase;
93 	unsigned long		regsize;
94 	struct resource		*res;
95 	int			alarm_irq;
96 	int			periodic_irq;
97 	int			carry_irq;
98 	struct clk		*clk;
99 	struct rtc_device	*rtc_dev;
100 	spinlock_t		lock;
101 	unsigned long		capabilities;	/* See asm/rtc.h for cap bits */
102 	unsigned short		periodic_freq;
103 };
104 
105 static int __sh_rtc_interrupt(struct sh_rtc *rtc)
106 {
107 	unsigned int tmp, pending;
108 
109 	tmp = readb(rtc->regbase + RCR1);
110 	pending = tmp & RCR1_CF;
111 	tmp &= ~RCR1_CF;
112 	writeb(tmp, rtc->regbase + RCR1);
113 
114 	/* Users have requested One x Second IRQ */
115 	if (pending && rtc->periodic_freq & PF_OXS)
116 		rtc_update_irq(rtc->rtc_dev, 1, RTC_UF | RTC_IRQF);
117 
118 	return pending;
119 }
120 
121 static int __sh_rtc_alarm(struct sh_rtc *rtc)
122 {
123 	unsigned int tmp, pending;
124 
125 	tmp = readb(rtc->regbase + RCR1);
126 	pending = tmp & RCR1_AF;
127 	tmp &= ~(RCR1_AF | RCR1_AIE);
128 	writeb(tmp, rtc->regbase + RCR1);
129 
130 	if (pending)
131 		rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF);
132 
133 	return pending;
134 }
135 
136 static int __sh_rtc_periodic(struct sh_rtc *rtc)
137 {
138 	struct rtc_device *rtc_dev = rtc->rtc_dev;
139 	struct rtc_task *irq_task;
140 	unsigned int tmp, pending;
141 
142 	tmp = readb(rtc->regbase + RCR2);
143 	pending = tmp & RCR2_PEF;
144 	tmp &= ~RCR2_PEF;
145 	writeb(tmp, rtc->regbase + RCR2);
146 
147 	if (!pending)
148 		return 0;
149 
150 	/* Half period enabled than one skipped and the next notified */
151 	if ((rtc->periodic_freq & PF_HP) && (rtc->periodic_freq & PF_COUNT))
152 		rtc->periodic_freq &= ~PF_COUNT;
153 	else {
154 		if (rtc->periodic_freq & PF_HP)
155 			rtc->periodic_freq |= PF_COUNT;
156 		if (rtc->periodic_freq & PF_KOU) {
157 			spin_lock(&rtc_dev->irq_task_lock);
158 			irq_task = rtc_dev->irq_task;
159 			if (irq_task)
160 				irq_task->func(irq_task->private_data);
161 			spin_unlock(&rtc_dev->irq_task_lock);
162 		} else
163 			rtc_update_irq(rtc->rtc_dev, 1, RTC_PF | RTC_IRQF);
164 	}
165 
166 	return pending;
167 }
168 
169 static irqreturn_t sh_rtc_interrupt(int irq, void *dev_id)
170 {
171 	struct sh_rtc *rtc = dev_id;
172 	int ret;
173 
174 	spin_lock(&rtc->lock);
175 	ret = __sh_rtc_interrupt(rtc);
176 	spin_unlock(&rtc->lock);
177 
178 	return IRQ_RETVAL(ret);
179 }
180 
181 static irqreturn_t sh_rtc_alarm(int irq, void *dev_id)
182 {
183 	struct sh_rtc *rtc = dev_id;
184 	int ret;
185 
186 	spin_lock(&rtc->lock);
187 	ret = __sh_rtc_alarm(rtc);
188 	spin_unlock(&rtc->lock);
189 
190 	return IRQ_RETVAL(ret);
191 }
192 
193 static irqreturn_t sh_rtc_periodic(int irq, void *dev_id)
194 {
195 	struct sh_rtc *rtc = dev_id;
196 	int ret;
197 
198 	spin_lock(&rtc->lock);
199 	ret = __sh_rtc_periodic(rtc);
200 	spin_unlock(&rtc->lock);
201 
202 	return IRQ_RETVAL(ret);
203 }
204 
205 static irqreturn_t sh_rtc_shared(int irq, void *dev_id)
206 {
207 	struct sh_rtc *rtc = dev_id;
208 	int ret;
209 
210 	spin_lock(&rtc->lock);
211 	ret = __sh_rtc_interrupt(rtc);
212 	ret |= __sh_rtc_alarm(rtc);
213 	ret |= __sh_rtc_periodic(rtc);
214 	spin_unlock(&rtc->lock);
215 
216 	return IRQ_RETVAL(ret);
217 }
218 
219 static int sh_rtc_irq_set_state(struct device *dev, int enable)
220 {
221 	struct sh_rtc *rtc = dev_get_drvdata(dev);
222 	unsigned int tmp;
223 
224 	spin_lock_irq(&rtc->lock);
225 
226 	tmp = readb(rtc->regbase + RCR2);
227 
228 	if (enable) {
229 		rtc->periodic_freq |= PF_KOU;
230 		tmp &= ~RCR2_PEF;	/* Clear PES bit */
231 		tmp |= (rtc->periodic_freq & ~PF_HP);	/* Set PES2-0 */
232 	} else {
233 		rtc->periodic_freq &= ~PF_KOU;
234 		tmp &= ~(RCR2_PESMASK | RCR2_PEF);
235 	}
236 
237 	writeb(tmp, rtc->regbase + RCR2);
238 
239 	spin_unlock_irq(&rtc->lock);
240 
241 	return 0;
242 }
243 
244 static int sh_rtc_irq_set_freq(struct device *dev, int freq)
245 {
246 	struct sh_rtc *rtc = dev_get_drvdata(dev);
247 	int tmp, ret = 0;
248 
249 	spin_lock_irq(&rtc->lock);
250 	tmp = rtc->periodic_freq & PF_MASK;
251 
252 	switch (freq) {
253 	case 0:
254 		rtc->periodic_freq = 0x00;
255 		break;
256 	case 1:
257 		rtc->periodic_freq = 0x60;
258 		break;
259 	case 2:
260 		rtc->periodic_freq = 0x50;
261 		break;
262 	case 4:
263 		rtc->periodic_freq = 0x40;
264 		break;
265 	case 8:
266 		rtc->periodic_freq = 0x30 | PF_HP;
267 		break;
268 	case 16:
269 		rtc->periodic_freq = 0x30;
270 		break;
271 	case 32:
272 		rtc->periodic_freq = 0x20 | PF_HP;
273 		break;
274 	case 64:
275 		rtc->periodic_freq = 0x20;
276 		break;
277 	case 128:
278 		rtc->periodic_freq = 0x10 | PF_HP;
279 		break;
280 	case 256:
281 		rtc->periodic_freq = 0x10;
282 		break;
283 	default:
284 		ret = -ENOTSUPP;
285 	}
286 
287 	if (ret == 0)
288 		rtc->periodic_freq |= tmp;
289 
290 	spin_unlock_irq(&rtc->lock);
291 	return ret;
292 }
293 
294 static inline void sh_rtc_setaie(struct device *dev, unsigned int enable)
295 {
296 	struct sh_rtc *rtc = dev_get_drvdata(dev);
297 	unsigned int tmp;
298 
299 	spin_lock_irq(&rtc->lock);
300 
301 	tmp = readb(rtc->regbase + RCR1);
302 
303 	if (enable)
304 		tmp |= RCR1_AIE;
305 	else
306 		tmp &= ~RCR1_AIE;
307 
308 	writeb(tmp, rtc->regbase + RCR1);
309 
310 	spin_unlock_irq(&rtc->lock);
311 }
312 
313 static int sh_rtc_proc(struct device *dev, struct seq_file *seq)
314 {
315 	struct sh_rtc *rtc = dev_get_drvdata(dev);
316 	unsigned int tmp;
317 
318 	tmp = readb(rtc->regbase + RCR1);
319 	seq_printf(seq, "carry_IRQ\t: %s\n", (tmp & RCR1_CIE) ? "yes" : "no");
320 
321 	tmp = readb(rtc->regbase + RCR2);
322 	seq_printf(seq, "periodic_IRQ\t: %s\n",
323 		   (tmp & RCR2_PESMASK) ? "yes" : "no");
324 
325 	return 0;
326 }
327 
328 static inline void sh_rtc_setcie(struct device *dev, unsigned int enable)
329 {
330 	struct sh_rtc *rtc = dev_get_drvdata(dev);
331 	unsigned int tmp;
332 
333 	spin_lock_irq(&rtc->lock);
334 
335 	tmp = readb(rtc->regbase + RCR1);
336 
337 	if (!enable)
338 		tmp &= ~RCR1_CIE;
339 	else
340 		tmp |= RCR1_CIE;
341 
342 	writeb(tmp, rtc->regbase + RCR1);
343 
344 	spin_unlock_irq(&rtc->lock);
345 }
346 
347 static int sh_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
348 {
349 	sh_rtc_setaie(dev, enabled);
350 	return 0;
351 }
352 
353 static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm)
354 {
355 	struct platform_device *pdev = to_platform_device(dev);
356 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
357 	unsigned int sec128, sec2, yr, yr100, cf_bit;
358 
359 	do {
360 		unsigned int tmp;
361 
362 		spin_lock_irq(&rtc->lock);
363 
364 		tmp = readb(rtc->regbase + RCR1);
365 		tmp &= ~RCR1_CF; /* Clear CF-bit */
366 		tmp |= RCR1_CIE;
367 		writeb(tmp, rtc->regbase + RCR1);
368 
369 		sec128 = readb(rtc->regbase + R64CNT);
370 
371 		tm->tm_sec	= bcd2bin(readb(rtc->regbase + RSECCNT));
372 		tm->tm_min	= bcd2bin(readb(rtc->regbase + RMINCNT));
373 		tm->tm_hour	= bcd2bin(readb(rtc->regbase + RHRCNT));
374 		tm->tm_wday	= bcd2bin(readb(rtc->regbase + RWKCNT));
375 		tm->tm_mday	= bcd2bin(readb(rtc->regbase + RDAYCNT));
376 		tm->tm_mon	= bcd2bin(readb(rtc->regbase + RMONCNT)) - 1;
377 
378 		if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
379 			yr  = readw(rtc->regbase + RYRCNT);
380 			yr100 = bcd2bin(yr >> 8);
381 			yr &= 0xff;
382 		} else {
383 			yr  = readb(rtc->regbase + RYRCNT);
384 			yr100 = bcd2bin((yr == 0x99) ? 0x19 : 0x20);
385 		}
386 
387 		tm->tm_year = (yr100 * 100 + bcd2bin(yr)) - 1900;
388 
389 		sec2 = readb(rtc->regbase + R64CNT);
390 		cf_bit = readb(rtc->regbase + RCR1) & RCR1_CF;
391 
392 		spin_unlock_irq(&rtc->lock);
393 	} while (cf_bit != 0 || ((sec128 ^ sec2) & RTC_BIT_INVERTED) != 0);
394 
395 #if RTC_BIT_INVERTED != 0
396 	if ((sec128 & RTC_BIT_INVERTED))
397 		tm->tm_sec--;
398 #endif
399 
400 	/* only keep the carry interrupt enabled if UIE is on */
401 	if (!(rtc->periodic_freq & PF_OXS))
402 		sh_rtc_setcie(dev, 0);
403 
404 	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
405 		"mday=%d, mon=%d, year=%d, wday=%d\n",
406 		__func__,
407 		tm->tm_sec, tm->tm_min, tm->tm_hour,
408 		tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
409 
410 	return rtc_valid_tm(tm);
411 }
412 
413 static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm)
414 {
415 	struct platform_device *pdev = to_platform_device(dev);
416 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
417 	unsigned int tmp;
418 	int year;
419 
420 	spin_lock_irq(&rtc->lock);
421 
422 	/* Reset pre-scaler & stop RTC */
423 	tmp = readb(rtc->regbase + RCR2);
424 	tmp |= RCR2_RESET;
425 	tmp &= ~RCR2_START;
426 	writeb(tmp, rtc->regbase + RCR2);
427 
428 	writeb(bin2bcd(tm->tm_sec),  rtc->regbase + RSECCNT);
429 	writeb(bin2bcd(tm->tm_min),  rtc->regbase + RMINCNT);
430 	writeb(bin2bcd(tm->tm_hour), rtc->regbase + RHRCNT);
431 	writeb(bin2bcd(tm->tm_wday), rtc->regbase + RWKCNT);
432 	writeb(bin2bcd(tm->tm_mday), rtc->regbase + RDAYCNT);
433 	writeb(bin2bcd(tm->tm_mon + 1), rtc->regbase + RMONCNT);
434 
435 	if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
436 		year = (bin2bcd((tm->tm_year + 1900) / 100) << 8) |
437 			bin2bcd(tm->tm_year % 100);
438 		writew(year, rtc->regbase + RYRCNT);
439 	} else {
440 		year = tm->tm_year % 100;
441 		writeb(bin2bcd(year), rtc->regbase + RYRCNT);
442 	}
443 
444 	/* Start RTC */
445 	tmp = readb(rtc->regbase + RCR2);
446 	tmp &= ~RCR2_RESET;
447 	tmp |= RCR2_RTCEN | RCR2_START;
448 	writeb(tmp, rtc->regbase + RCR2);
449 
450 	spin_unlock_irq(&rtc->lock);
451 
452 	return 0;
453 }
454 
455 static inline int sh_rtc_read_alarm_value(struct sh_rtc *rtc, int reg_off)
456 {
457 	unsigned int byte;
458 	int value = 0xff;	/* return 0xff for ignored values */
459 
460 	byte = readb(rtc->regbase + reg_off);
461 	if (byte & AR_ENB) {
462 		byte &= ~AR_ENB;	/* strip the enable bit */
463 		value = bcd2bin(byte);
464 	}
465 
466 	return value;
467 }
468 
469 static int sh_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
470 {
471 	struct platform_device *pdev = to_platform_device(dev);
472 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
473 	struct rtc_time *tm = &wkalrm->time;
474 
475 	spin_lock_irq(&rtc->lock);
476 
477 	tm->tm_sec	= sh_rtc_read_alarm_value(rtc, RSECAR);
478 	tm->tm_min	= sh_rtc_read_alarm_value(rtc, RMINAR);
479 	tm->tm_hour	= sh_rtc_read_alarm_value(rtc, RHRAR);
480 	tm->tm_wday	= sh_rtc_read_alarm_value(rtc, RWKAR);
481 	tm->tm_mday	= sh_rtc_read_alarm_value(rtc, RDAYAR);
482 	tm->tm_mon	= sh_rtc_read_alarm_value(rtc, RMONAR);
483 	if (tm->tm_mon > 0)
484 		tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */
485 	tm->tm_year     = 0xffff;
486 
487 	wkalrm->enabled = (readb(rtc->regbase + RCR1) & RCR1_AIE) ? 1 : 0;
488 
489 	spin_unlock_irq(&rtc->lock);
490 
491 	return 0;
492 }
493 
494 static inline void sh_rtc_write_alarm_value(struct sh_rtc *rtc,
495 					    int value, int reg_off)
496 {
497 	/* < 0 for a value that is ignored */
498 	if (value < 0)
499 		writeb(0, rtc->regbase + reg_off);
500 	else
501 		writeb(bin2bcd(value) | AR_ENB,  rtc->regbase + reg_off);
502 }
503 
504 static int sh_rtc_check_alarm(struct rtc_time *tm)
505 {
506 	/*
507 	 * The original rtc says anything > 0xc0 is "don't care" or "match
508 	 * all" - most users use 0xff but rtc-dev uses -1 for the same thing.
509 	 * The original rtc doesn't support years - some things use -1 and
510 	 * some 0xffff. We use -1 to make out tests easier.
511 	 */
512 	if (tm->tm_year == 0xffff)
513 		tm->tm_year = -1;
514 	if (tm->tm_mon >= 0xff)
515 		tm->tm_mon = -1;
516 	if (tm->tm_mday >= 0xff)
517 		tm->tm_mday = -1;
518 	if (tm->tm_wday >= 0xff)
519 		tm->tm_wday = -1;
520 	if (tm->tm_hour >= 0xff)
521 		tm->tm_hour = -1;
522 	if (tm->tm_min >= 0xff)
523 		tm->tm_min = -1;
524 	if (tm->tm_sec >= 0xff)
525 		tm->tm_sec = -1;
526 
527 	if (tm->tm_year > 9999 ||
528 		tm->tm_mon >= 12 ||
529 		tm->tm_mday == 0 || tm->tm_mday >= 32 ||
530 		tm->tm_wday >= 7 ||
531 		tm->tm_hour >= 24 ||
532 		tm->tm_min >= 60 ||
533 		tm->tm_sec >= 60)
534 		return -EINVAL;
535 
536 	return 0;
537 }
538 
539 static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
540 {
541 	struct platform_device *pdev = to_platform_device(dev);
542 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
543 	unsigned int rcr1;
544 	struct rtc_time *tm = &wkalrm->time;
545 	int mon, err;
546 
547 	err = sh_rtc_check_alarm(tm);
548 	if (unlikely(err < 0))
549 		return err;
550 
551 	spin_lock_irq(&rtc->lock);
552 
553 	/* disable alarm interrupt and clear the alarm flag */
554 	rcr1 = readb(rtc->regbase + RCR1);
555 	rcr1 &= ~(RCR1_AF | RCR1_AIE);
556 	writeb(rcr1, rtc->regbase + RCR1);
557 
558 	/* set alarm time */
559 	sh_rtc_write_alarm_value(rtc, tm->tm_sec,  RSECAR);
560 	sh_rtc_write_alarm_value(rtc, tm->tm_min,  RMINAR);
561 	sh_rtc_write_alarm_value(rtc, tm->tm_hour, RHRAR);
562 	sh_rtc_write_alarm_value(rtc, tm->tm_wday, RWKAR);
563 	sh_rtc_write_alarm_value(rtc, tm->tm_mday, RDAYAR);
564 	mon = tm->tm_mon;
565 	if (mon >= 0)
566 		mon += 1;
567 	sh_rtc_write_alarm_value(rtc, mon, RMONAR);
568 
569 	if (wkalrm->enabled) {
570 		rcr1 |= RCR1_AIE;
571 		writeb(rcr1, rtc->regbase + RCR1);
572 	}
573 
574 	spin_unlock_irq(&rtc->lock);
575 
576 	return 0;
577 }
578 
579 static struct rtc_class_ops sh_rtc_ops = {
580 	.read_time	= sh_rtc_read_time,
581 	.set_time	= sh_rtc_set_time,
582 	.read_alarm	= sh_rtc_read_alarm,
583 	.set_alarm	= sh_rtc_set_alarm,
584 	.proc		= sh_rtc_proc,
585 	.alarm_irq_enable = sh_rtc_alarm_irq_enable,
586 };
587 
588 static int __init sh_rtc_probe(struct platform_device *pdev)
589 {
590 	struct sh_rtc *rtc;
591 	struct resource *res;
592 	struct rtc_time r;
593 	char clk_name[6];
594 	int clk_id, ret;
595 
596 	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
597 	if (unlikely(!rtc))
598 		return -ENOMEM;
599 
600 	spin_lock_init(&rtc->lock);
601 
602 	/* get periodic/carry/alarm irqs */
603 	ret = platform_get_irq(pdev, 0);
604 	if (unlikely(ret <= 0)) {
605 		dev_err(&pdev->dev, "No IRQ resource\n");
606 		return -ENOENT;
607 	}
608 
609 	rtc->periodic_irq = ret;
610 	rtc->carry_irq = platform_get_irq(pdev, 1);
611 	rtc->alarm_irq = platform_get_irq(pdev, 2);
612 
613 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
614 	if (unlikely(res == NULL)) {
615 		dev_err(&pdev->dev, "No IO resource\n");
616 		return -ENOENT;
617 	}
618 
619 	rtc->regsize = resource_size(res);
620 
621 	rtc->res = devm_request_mem_region(&pdev->dev, res->start,
622 					rtc->regsize, pdev->name);
623 	if (unlikely(!rtc->res))
624 		return -EBUSY;
625 
626 	rtc->regbase = devm_ioremap_nocache(&pdev->dev, rtc->res->start,
627 					rtc->regsize);
628 	if (unlikely(!rtc->regbase))
629 		return -EINVAL;
630 
631 	clk_id = pdev->id;
632 	/* With a single device, the clock id is still "rtc0" */
633 	if (clk_id < 0)
634 		clk_id = 0;
635 
636 	snprintf(clk_name, sizeof(clk_name), "rtc%d", clk_id);
637 
638 	rtc->clk = devm_clk_get(&pdev->dev, clk_name);
639 	if (IS_ERR(rtc->clk)) {
640 		/*
641 		 * No error handling for rtc->clk intentionally, not all
642 		 * platforms will have a unique clock for the RTC, and
643 		 * the clk API can handle the struct clk pointer being
644 		 * NULL.
645 		 */
646 		rtc->clk = NULL;
647 	}
648 
649 	clk_enable(rtc->clk);
650 
651 	rtc->capabilities = RTC_DEF_CAPABILITIES;
652 	if (dev_get_platdata(&pdev->dev)) {
653 		struct sh_rtc_platform_info *pinfo =
654 			dev_get_platdata(&pdev->dev);
655 
656 		/*
657 		 * Some CPUs have special capabilities in addition to the
658 		 * default set. Add those in here.
659 		 */
660 		rtc->capabilities |= pinfo->capabilities;
661 	}
662 
663 	if (rtc->carry_irq <= 0) {
664 		/* register shared periodic/carry/alarm irq */
665 		ret = devm_request_irq(&pdev->dev, rtc->periodic_irq,
666 				sh_rtc_shared, 0, "sh-rtc", rtc);
667 		if (unlikely(ret)) {
668 			dev_err(&pdev->dev,
669 				"request IRQ failed with %d, IRQ %d\n", ret,
670 				rtc->periodic_irq);
671 			goto err_unmap;
672 		}
673 	} else {
674 		/* register periodic/carry/alarm irqs */
675 		ret = devm_request_irq(&pdev->dev, rtc->periodic_irq,
676 				sh_rtc_periodic, 0, "sh-rtc period", rtc);
677 		if (unlikely(ret)) {
678 			dev_err(&pdev->dev,
679 				"request period IRQ failed with %d, IRQ %d\n",
680 				ret, rtc->periodic_irq);
681 			goto err_unmap;
682 		}
683 
684 		ret = devm_request_irq(&pdev->dev, rtc->carry_irq,
685 				sh_rtc_interrupt, 0, "sh-rtc carry", rtc);
686 		if (unlikely(ret)) {
687 			dev_err(&pdev->dev,
688 				"request carry IRQ failed with %d, IRQ %d\n",
689 				ret, rtc->carry_irq);
690 			goto err_unmap;
691 		}
692 
693 		ret = devm_request_irq(&pdev->dev, rtc->alarm_irq,
694 				sh_rtc_alarm, 0, "sh-rtc alarm", rtc);
695 		if (unlikely(ret)) {
696 			dev_err(&pdev->dev,
697 				"request alarm IRQ failed with %d, IRQ %d\n",
698 				ret, rtc->alarm_irq);
699 			goto err_unmap;
700 		}
701 	}
702 
703 	platform_set_drvdata(pdev, rtc);
704 
705 	/* everything disabled by default */
706 	sh_rtc_irq_set_freq(&pdev->dev, 0);
707 	sh_rtc_irq_set_state(&pdev->dev, 0);
708 	sh_rtc_setaie(&pdev->dev, 0);
709 	sh_rtc_setcie(&pdev->dev, 0);
710 
711 	rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "sh",
712 					   &sh_rtc_ops, THIS_MODULE);
713 	if (IS_ERR(rtc->rtc_dev)) {
714 		ret = PTR_ERR(rtc->rtc_dev);
715 		goto err_unmap;
716 	}
717 
718 	rtc->rtc_dev->max_user_freq = 256;
719 
720 	/* reset rtc to epoch 0 if time is invalid */
721 	if (rtc_read_time(rtc->rtc_dev, &r) < 0) {
722 		rtc_time_to_tm(0, &r);
723 		rtc_set_time(rtc->rtc_dev, &r);
724 	}
725 
726 	device_init_wakeup(&pdev->dev, 1);
727 	return 0;
728 
729 err_unmap:
730 	clk_disable(rtc->clk);
731 
732 	return ret;
733 }
734 
735 static int __exit sh_rtc_remove(struct platform_device *pdev)
736 {
737 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
738 
739 	sh_rtc_irq_set_state(&pdev->dev, 0);
740 
741 	sh_rtc_setaie(&pdev->dev, 0);
742 	sh_rtc_setcie(&pdev->dev, 0);
743 
744 	clk_disable(rtc->clk);
745 
746 	return 0;
747 }
748 
749 static void sh_rtc_set_irq_wake(struct device *dev, int enabled)
750 {
751 	struct platform_device *pdev = to_platform_device(dev);
752 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
753 
754 	irq_set_irq_wake(rtc->periodic_irq, enabled);
755 
756 	if (rtc->carry_irq > 0) {
757 		irq_set_irq_wake(rtc->carry_irq, enabled);
758 		irq_set_irq_wake(rtc->alarm_irq, enabled);
759 	}
760 }
761 
762 #ifdef CONFIG_PM_SLEEP
763 static int sh_rtc_suspend(struct device *dev)
764 {
765 	if (device_may_wakeup(dev))
766 		sh_rtc_set_irq_wake(dev, 1);
767 
768 	return 0;
769 }
770 
771 static int sh_rtc_resume(struct device *dev)
772 {
773 	if (device_may_wakeup(dev))
774 		sh_rtc_set_irq_wake(dev, 0);
775 
776 	return 0;
777 }
778 #endif
779 
780 static SIMPLE_DEV_PM_OPS(sh_rtc_pm_ops, sh_rtc_suspend, sh_rtc_resume);
781 
782 static struct platform_driver sh_rtc_platform_driver = {
783 	.driver		= {
784 		.name	= DRV_NAME,
785 		.owner	= THIS_MODULE,
786 		.pm	= &sh_rtc_pm_ops,
787 	},
788 	.remove		= __exit_p(sh_rtc_remove),
789 };
790 
791 module_platform_driver_probe(sh_rtc_platform_driver, sh_rtc_probe);
792 
793 MODULE_DESCRIPTION("SuperH on-chip RTC driver");
794 MODULE_VERSION(DRV_VERSION);
795 MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, "
796 	      "Jamie Lenehan <lenehan@twibble.org>, "
797 	      "Angelo Castello <angelo.castello@st.com>");
798 MODULE_LICENSE("GPL");
799 MODULE_ALIAS("platform:" DRV_NAME);
800