xref: /linux/drivers/rtc/rtc-sh.c (revision 74ce1896c6c65b2f8cccbf59162d542988835835)
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 #ifdef CONFIG_SUPERH
31 #include <asm/rtc.h>
32 #else
33 /* Default values for RZ/A RTC */
34 #define rtc_reg_size		sizeof(u16)
35 #define RTC_BIT_INVERTED        0	/* no chip bugs */
36 #define RTC_CAP_4_DIGIT_YEAR    (1 << 0)
37 #define RTC_DEF_CAPABILITIES    RTC_CAP_4_DIGIT_YEAR
38 #endif
39 
40 #define DRV_NAME	"sh-rtc"
41 
42 #define RTC_REG(r)	((r) * rtc_reg_size)
43 
44 #define R64CNT		RTC_REG(0)
45 
46 #define RSECCNT		RTC_REG(1)	/* RTC sec */
47 #define RMINCNT		RTC_REG(2)	/* RTC min */
48 #define RHRCNT		RTC_REG(3)	/* RTC hour */
49 #define RWKCNT		RTC_REG(4)	/* RTC week */
50 #define RDAYCNT		RTC_REG(5)	/* RTC day */
51 #define RMONCNT		RTC_REG(6)	/* RTC month */
52 #define RYRCNT		RTC_REG(7)	/* RTC year */
53 #define RSECAR		RTC_REG(8)	/* ALARM sec */
54 #define RMINAR		RTC_REG(9)	/* ALARM min */
55 #define RHRAR		RTC_REG(10)	/* ALARM hour */
56 #define RWKAR		RTC_REG(11)	/* ALARM week */
57 #define RDAYAR		RTC_REG(12)	/* ALARM day */
58 #define RMONAR		RTC_REG(13)	/* ALARM month */
59 #define RCR1		RTC_REG(14)	/* Control */
60 #define RCR2		RTC_REG(15)	/* Control */
61 
62 /*
63  * Note on RYRAR and RCR3: Up until this point most of the register
64  * definitions are consistent across all of the available parts. However,
65  * the placement of the optional RYRAR and RCR3 (the RYRAR control
66  * register used to control RYRCNT/RYRAR compare) varies considerably
67  * across various parts, occasionally being mapped in to a completely
68  * unrelated address space. For proper RYRAR support a separate resource
69  * would have to be handed off, but as this is purely optional in
70  * practice, we simply opt not to support it, thereby keeping the code
71  * quite a bit more simplified.
72  */
73 
74 /* ALARM Bits - or with BCD encoded value */
75 #define AR_ENB		0x80	/* Enable for alarm cmp   */
76 
77 /* Period Bits */
78 #define PF_HP		0x100	/* Enable Half Period to support 8,32,128Hz */
79 #define PF_COUNT	0x200	/* Half periodic counter */
80 #define PF_OXS		0x400	/* Periodic One x Second */
81 #define PF_KOU		0x800	/* Kernel or User periodic request 1=kernel */
82 #define PF_MASK		0xf00
83 
84 /* RCR1 Bits */
85 #define RCR1_CF		0x80	/* Carry Flag             */
86 #define RCR1_CIE	0x10	/* Carry Interrupt Enable */
87 #define RCR1_AIE	0x08	/* Alarm Interrupt Enable */
88 #define RCR1_AF		0x01	/* Alarm Flag             */
89 
90 /* RCR2 Bits */
91 #define RCR2_PEF	0x80	/* PEriodic interrupt Flag */
92 #define RCR2_PESMASK	0x70	/* Periodic interrupt Set  */
93 #define RCR2_RTCEN	0x08	/* ENable RTC              */
94 #define RCR2_ADJ	0x04	/* ADJustment (30-second)  */
95 #define RCR2_RESET	0x02	/* Reset bit               */
96 #define RCR2_START	0x01	/* Start bit               */
97 
98 struct sh_rtc {
99 	void __iomem		*regbase;
100 	unsigned long		regsize;
101 	struct resource		*res;
102 	int			alarm_irq;
103 	int			periodic_irq;
104 	int			carry_irq;
105 	struct clk		*clk;
106 	struct rtc_device	*rtc_dev;
107 	spinlock_t		lock;
108 	unsigned long		capabilities;	/* See asm/rtc.h for cap bits */
109 	unsigned short		periodic_freq;
110 };
111 
112 static int __sh_rtc_interrupt(struct sh_rtc *rtc)
113 {
114 	unsigned int tmp, pending;
115 
116 	tmp = readb(rtc->regbase + RCR1);
117 	pending = tmp & RCR1_CF;
118 	tmp &= ~RCR1_CF;
119 	writeb(tmp, rtc->regbase + RCR1);
120 
121 	/* Users have requested One x Second IRQ */
122 	if (pending && rtc->periodic_freq & PF_OXS)
123 		rtc_update_irq(rtc->rtc_dev, 1, RTC_UF | RTC_IRQF);
124 
125 	return pending;
126 }
127 
128 static int __sh_rtc_alarm(struct sh_rtc *rtc)
129 {
130 	unsigned int tmp, pending;
131 
132 	tmp = readb(rtc->regbase + RCR1);
133 	pending = tmp & RCR1_AF;
134 	tmp &= ~(RCR1_AF | RCR1_AIE);
135 	writeb(tmp, rtc->regbase + RCR1);
136 
137 	if (pending)
138 		rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF);
139 
140 	return pending;
141 }
142 
143 static int __sh_rtc_periodic(struct sh_rtc *rtc)
144 {
145 	struct rtc_device *rtc_dev = rtc->rtc_dev;
146 	struct rtc_task *irq_task;
147 	unsigned int tmp, pending;
148 
149 	tmp = readb(rtc->regbase + RCR2);
150 	pending = tmp & RCR2_PEF;
151 	tmp &= ~RCR2_PEF;
152 	writeb(tmp, rtc->regbase + RCR2);
153 
154 	if (!pending)
155 		return 0;
156 
157 	/* Half period enabled than one skipped and the next notified */
158 	if ((rtc->periodic_freq & PF_HP) && (rtc->periodic_freq & PF_COUNT))
159 		rtc->periodic_freq &= ~PF_COUNT;
160 	else {
161 		if (rtc->periodic_freq & PF_HP)
162 			rtc->periodic_freq |= PF_COUNT;
163 		if (rtc->periodic_freq & PF_KOU) {
164 			spin_lock(&rtc_dev->irq_task_lock);
165 			irq_task = rtc_dev->irq_task;
166 			if (irq_task)
167 				irq_task->func(irq_task->private_data);
168 			spin_unlock(&rtc_dev->irq_task_lock);
169 		} else
170 			rtc_update_irq(rtc->rtc_dev, 1, RTC_PF | RTC_IRQF);
171 	}
172 
173 	return pending;
174 }
175 
176 static irqreturn_t sh_rtc_interrupt(int irq, void *dev_id)
177 {
178 	struct sh_rtc *rtc = dev_id;
179 	int ret;
180 
181 	spin_lock(&rtc->lock);
182 	ret = __sh_rtc_interrupt(rtc);
183 	spin_unlock(&rtc->lock);
184 
185 	return IRQ_RETVAL(ret);
186 }
187 
188 static irqreturn_t sh_rtc_alarm(int irq, void *dev_id)
189 {
190 	struct sh_rtc *rtc = dev_id;
191 	int ret;
192 
193 	spin_lock(&rtc->lock);
194 	ret = __sh_rtc_alarm(rtc);
195 	spin_unlock(&rtc->lock);
196 
197 	return IRQ_RETVAL(ret);
198 }
199 
200 static irqreturn_t sh_rtc_periodic(int irq, void *dev_id)
201 {
202 	struct sh_rtc *rtc = dev_id;
203 	int ret;
204 
205 	spin_lock(&rtc->lock);
206 	ret = __sh_rtc_periodic(rtc);
207 	spin_unlock(&rtc->lock);
208 
209 	return IRQ_RETVAL(ret);
210 }
211 
212 static irqreturn_t sh_rtc_shared(int irq, void *dev_id)
213 {
214 	struct sh_rtc *rtc = dev_id;
215 	int ret;
216 
217 	spin_lock(&rtc->lock);
218 	ret = __sh_rtc_interrupt(rtc);
219 	ret |= __sh_rtc_alarm(rtc);
220 	ret |= __sh_rtc_periodic(rtc);
221 	spin_unlock(&rtc->lock);
222 
223 	return IRQ_RETVAL(ret);
224 }
225 
226 static int sh_rtc_irq_set_state(struct device *dev, int enable)
227 {
228 	struct sh_rtc *rtc = dev_get_drvdata(dev);
229 	unsigned int tmp;
230 
231 	spin_lock_irq(&rtc->lock);
232 
233 	tmp = readb(rtc->regbase + RCR2);
234 
235 	if (enable) {
236 		rtc->periodic_freq |= PF_KOU;
237 		tmp &= ~RCR2_PEF;	/* Clear PES bit */
238 		tmp |= (rtc->periodic_freq & ~PF_HP);	/* Set PES2-0 */
239 	} else {
240 		rtc->periodic_freq &= ~PF_KOU;
241 		tmp &= ~(RCR2_PESMASK | RCR2_PEF);
242 	}
243 
244 	writeb(tmp, rtc->regbase + RCR2);
245 
246 	spin_unlock_irq(&rtc->lock);
247 
248 	return 0;
249 }
250 
251 static int sh_rtc_irq_set_freq(struct device *dev, int freq)
252 {
253 	struct sh_rtc *rtc = dev_get_drvdata(dev);
254 	int tmp, ret = 0;
255 
256 	spin_lock_irq(&rtc->lock);
257 	tmp = rtc->periodic_freq & PF_MASK;
258 
259 	switch (freq) {
260 	case 0:
261 		rtc->periodic_freq = 0x00;
262 		break;
263 	case 1:
264 		rtc->periodic_freq = 0x60;
265 		break;
266 	case 2:
267 		rtc->periodic_freq = 0x50;
268 		break;
269 	case 4:
270 		rtc->periodic_freq = 0x40;
271 		break;
272 	case 8:
273 		rtc->periodic_freq = 0x30 | PF_HP;
274 		break;
275 	case 16:
276 		rtc->periodic_freq = 0x30;
277 		break;
278 	case 32:
279 		rtc->periodic_freq = 0x20 | PF_HP;
280 		break;
281 	case 64:
282 		rtc->periodic_freq = 0x20;
283 		break;
284 	case 128:
285 		rtc->periodic_freq = 0x10 | PF_HP;
286 		break;
287 	case 256:
288 		rtc->periodic_freq = 0x10;
289 		break;
290 	default:
291 		ret = -ENOTSUPP;
292 	}
293 
294 	if (ret == 0)
295 		rtc->periodic_freq |= tmp;
296 
297 	spin_unlock_irq(&rtc->lock);
298 	return ret;
299 }
300 
301 static inline void sh_rtc_setaie(struct device *dev, unsigned int enable)
302 {
303 	struct sh_rtc *rtc = dev_get_drvdata(dev);
304 	unsigned int tmp;
305 
306 	spin_lock_irq(&rtc->lock);
307 
308 	tmp = readb(rtc->regbase + RCR1);
309 
310 	if (enable)
311 		tmp |= RCR1_AIE;
312 	else
313 		tmp &= ~RCR1_AIE;
314 
315 	writeb(tmp, rtc->regbase + RCR1);
316 
317 	spin_unlock_irq(&rtc->lock);
318 }
319 
320 static int sh_rtc_proc(struct device *dev, struct seq_file *seq)
321 {
322 	struct sh_rtc *rtc = dev_get_drvdata(dev);
323 	unsigned int tmp;
324 
325 	tmp = readb(rtc->regbase + RCR1);
326 	seq_printf(seq, "carry_IRQ\t: %s\n", (tmp & RCR1_CIE) ? "yes" : "no");
327 
328 	tmp = readb(rtc->regbase + RCR2);
329 	seq_printf(seq, "periodic_IRQ\t: %s\n",
330 		   (tmp & RCR2_PESMASK) ? "yes" : "no");
331 
332 	return 0;
333 }
334 
335 static inline void sh_rtc_setcie(struct device *dev, unsigned int enable)
336 {
337 	struct sh_rtc *rtc = dev_get_drvdata(dev);
338 	unsigned int tmp;
339 
340 	spin_lock_irq(&rtc->lock);
341 
342 	tmp = readb(rtc->regbase + RCR1);
343 
344 	if (!enable)
345 		tmp &= ~RCR1_CIE;
346 	else
347 		tmp |= RCR1_CIE;
348 
349 	writeb(tmp, rtc->regbase + RCR1);
350 
351 	spin_unlock_irq(&rtc->lock);
352 }
353 
354 static int sh_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
355 {
356 	sh_rtc_setaie(dev, enabled);
357 	return 0;
358 }
359 
360 static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm)
361 {
362 	struct platform_device *pdev = to_platform_device(dev);
363 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
364 	unsigned int sec128, sec2, yr, yr100, cf_bit;
365 
366 	do {
367 		unsigned int tmp;
368 
369 		spin_lock_irq(&rtc->lock);
370 
371 		tmp = readb(rtc->regbase + RCR1);
372 		tmp &= ~RCR1_CF; /* Clear CF-bit */
373 		tmp |= RCR1_CIE;
374 		writeb(tmp, rtc->regbase + RCR1);
375 
376 		sec128 = readb(rtc->regbase + R64CNT);
377 
378 		tm->tm_sec	= bcd2bin(readb(rtc->regbase + RSECCNT));
379 		tm->tm_min	= bcd2bin(readb(rtc->regbase + RMINCNT));
380 		tm->tm_hour	= bcd2bin(readb(rtc->regbase + RHRCNT));
381 		tm->tm_wday	= bcd2bin(readb(rtc->regbase + RWKCNT));
382 		tm->tm_mday	= bcd2bin(readb(rtc->regbase + RDAYCNT));
383 		tm->tm_mon	= bcd2bin(readb(rtc->regbase + RMONCNT)) - 1;
384 
385 		if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
386 			yr  = readw(rtc->regbase + RYRCNT);
387 			yr100 = bcd2bin(yr >> 8);
388 			yr &= 0xff;
389 		} else {
390 			yr  = readb(rtc->regbase + RYRCNT);
391 			yr100 = bcd2bin((yr == 0x99) ? 0x19 : 0x20);
392 		}
393 
394 		tm->tm_year = (yr100 * 100 + bcd2bin(yr)) - 1900;
395 
396 		sec2 = readb(rtc->regbase + R64CNT);
397 		cf_bit = readb(rtc->regbase + RCR1) & RCR1_CF;
398 
399 		spin_unlock_irq(&rtc->lock);
400 	} while (cf_bit != 0 || ((sec128 ^ sec2) & RTC_BIT_INVERTED) != 0);
401 
402 #if RTC_BIT_INVERTED != 0
403 	if ((sec128 & RTC_BIT_INVERTED))
404 		tm->tm_sec--;
405 #endif
406 
407 	/* only keep the carry interrupt enabled if UIE is on */
408 	if (!(rtc->periodic_freq & PF_OXS))
409 		sh_rtc_setcie(dev, 0);
410 
411 	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
412 		"mday=%d, mon=%d, year=%d, wday=%d\n",
413 		__func__,
414 		tm->tm_sec, tm->tm_min, tm->tm_hour,
415 		tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
416 
417 	return rtc_valid_tm(tm);
418 }
419 
420 static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm)
421 {
422 	struct platform_device *pdev = to_platform_device(dev);
423 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
424 	unsigned int tmp;
425 	int year;
426 
427 	spin_lock_irq(&rtc->lock);
428 
429 	/* Reset pre-scaler & stop RTC */
430 	tmp = readb(rtc->regbase + RCR2);
431 	tmp |= RCR2_RESET;
432 	tmp &= ~RCR2_START;
433 	writeb(tmp, rtc->regbase + RCR2);
434 
435 	writeb(bin2bcd(tm->tm_sec),  rtc->regbase + RSECCNT);
436 	writeb(bin2bcd(tm->tm_min),  rtc->regbase + RMINCNT);
437 	writeb(bin2bcd(tm->tm_hour), rtc->regbase + RHRCNT);
438 	writeb(bin2bcd(tm->tm_wday), rtc->regbase + RWKCNT);
439 	writeb(bin2bcd(tm->tm_mday), rtc->regbase + RDAYCNT);
440 	writeb(bin2bcd(tm->tm_mon + 1), rtc->regbase + RMONCNT);
441 
442 	if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
443 		year = (bin2bcd((tm->tm_year + 1900) / 100) << 8) |
444 			bin2bcd(tm->tm_year % 100);
445 		writew(year, rtc->regbase + RYRCNT);
446 	} else {
447 		year = tm->tm_year % 100;
448 		writeb(bin2bcd(year), rtc->regbase + RYRCNT);
449 	}
450 
451 	/* Start RTC */
452 	tmp = readb(rtc->regbase + RCR2);
453 	tmp &= ~RCR2_RESET;
454 	tmp |= RCR2_RTCEN | RCR2_START;
455 	writeb(tmp, rtc->regbase + RCR2);
456 
457 	spin_unlock_irq(&rtc->lock);
458 
459 	return 0;
460 }
461 
462 static inline int sh_rtc_read_alarm_value(struct sh_rtc *rtc, int reg_off)
463 {
464 	unsigned int byte;
465 	int value = 0xff;	/* return 0xff for ignored values */
466 
467 	byte = readb(rtc->regbase + reg_off);
468 	if (byte & AR_ENB) {
469 		byte &= ~AR_ENB;	/* strip the enable bit */
470 		value = bcd2bin(byte);
471 	}
472 
473 	return value;
474 }
475 
476 static int sh_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
477 {
478 	struct platform_device *pdev = to_platform_device(dev);
479 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
480 	struct rtc_time *tm = &wkalrm->time;
481 
482 	spin_lock_irq(&rtc->lock);
483 
484 	tm->tm_sec	= sh_rtc_read_alarm_value(rtc, RSECAR);
485 	tm->tm_min	= sh_rtc_read_alarm_value(rtc, RMINAR);
486 	tm->tm_hour	= sh_rtc_read_alarm_value(rtc, RHRAR);
487 	tm->tm_wday	= sh_rtc_read_alarm_value(rtc, RWKAR);
488 	tm->tm_mday	= sh_rtc_read_alarm_value(rtc, RDAYAR);
489 	tm->tm_mon	= sh_rtc_read_alarm_value(rtc, RMONAR);
490 	if (tm->tm_mon > 0)
491 		tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */
492 
493 	wkalrm->enabled = (readb(rtc->regbase + RCR1) & RCR1_AIE) ? 1 : 0;
494 
495 	spin_unlock_irq(&rtc->lock);
496 
497 	return 0;
498 }
499 
500 static inline void sh_rtc_write_alarm_value(struct sh_rtc *rtc,
501 					    int value, int reg_off)
502 {
503 	/* < 0 for a value that is ignored */
504 	if (value < 0)
505 		writeb(0, rtc->regbase + reg_off);
506 	else
507 		writeb(bin2bcd(value) | AR_ENB,  rtc->regbase + reg_off);
508 }
509 
510 static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
511 {
512 	struct platform_device *pdev = to_platform_device(dev);
513 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
514 	unsigned int rcr1;
515 	struct rtc_time *tm = &wkalrm->time;
516 	int mon;
517 
518 	spin_lock_irq(&rtc->lock);
519 
520 	/* disable alarm interrupt and clear the alarm flag */
521 	rcr1 = readb(rtc->regbase + RCR1);
522 	rcr1 &= ~(RCR1_AF | RCR1_AIE);
523 	writeb(rcr1, rtc->regbase + RCR1);
524 
525 	/* set alarm time */
526 	sh_rtc_write_alarm_value(rtc, tm->tm_sec,  RSECAR);
527 	sh_rtc_write_alarm_value(rtc, tm->tm_min,  RMINAR);
528 	sh_rtc_write_alarm_value(rtc, tm->tm_hour, RHRAR);
529 	sh_rtc_write_alarm_value(rtc, tm->tm_wday, RWKAR);
530 	sh_rtc_write_alarm_value(rtc, tm->tm_mday, RDAYAR);
531 	mon = tm->tm_mon;
532 	if (mon >= 0)
533 		mon += 1;
534 	sh_rtc_write_alarm_value(rtc, mon, RMONAR);
535 
536 	if (wkalrm->enabled) {
537 		rcr1 |= RCR1_AIE;
538 		writeb(rcr1, rtc->regbase + RCR1);
539 	}
540 
541 	spin_unlock_irq(&rtc->lock);
542 
543 	return 0;
544 }
545 
546 static const struct rtc_class_ops sh_rtc_ops = {
547 	.read_time	= sh_rtc_read_time,
548 	.set_time	= sh_rtc_set_time,
549 	.read_alarm	= sh_rtc_read_alarm,
550 	.set_alarm	= sh_rtc_set_alarm,
551 	.proc		= sh_rtc_proc,
552 	.alarm_irq_enable = sh_rtc_alarm_irq_enable,
553 };
554 
555 static int __init sh_rtc_probe(struct platform_device *pdev)
556 {
557 	struct sh_rtc *rtc;
558 	struct resource *res;
559 	struct rtc_time r;
560 	char clk_name[6];
561 	int clk_id, ret;
562 
563 	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
564 	if (unlikely(!rtc))
565 		return -ENOMEM;
566 
567 	spin_lock_init(&rtc->lock);
568 
569 	/* get periodic/carry/alarm irqs */
570 	ret = platform_get_irq(pdev, 0);
571 	if (unlikely(ret <= 0)) {
572 		dev_err(&pdev->dev, "No IRQ resource\n");
573 		return -ENOENT;
574 	}
575 
576 	rtc->periodic_irq = ret;
577 	rtc->carry_irq = platform_get_irq(pdev, 1);
578 	rtc->alarm_irq = platform_get_irq(pdev, 2);
579 
580 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
581 	if (!res)
582 		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
583 	if (unlikely(res == NULL)) {
584 		dev_err(&pdev->dev, "No IO resource\n");
585 		return -ENOENT;
586 	}
587 
588 	rtc->regsize = resource_size(res);
589 
590 	rtc->res = devm_request_mem_region(&pdev->dev, res->start,
591 					rtc->regsize, pdev->name);
592 	if (unlikely(!rtc->res))
593 		return -EBUSY;
594 
595 	rtc->regbase = devm_ioremap_nocache(&pdev->dev, rtc->res->start,
596 					rtc->regsize);
597 	if (unlikely(!rtc->regbase))
598 		return -EINVAL;
599 
600 	if (!pdev->dev.of_node) {
601 		clk_id = pdev->id;
602 		/* With a single device, the clock id is still "rtc0" */
603 		if (clk_id < 0)
604 			clk_id = 0;
605 
606 		snprintf(clk_name, sizeof(clk_name), "rtc%d", clk_id);
607 	} else
608 		snprintf(clk_name, sizeof(clk_name), "fck");
609 
610 	rtc->clk = devm_clk_get(&pdev->dev, clk_name);
611 	if (IS_ERR(rtc->clk)) {
612 		/*
613 		 * No error handling for rtc->clk intentionally, not all
614 		 * platforms will have a unique clock for the RTC, and
615 		 * the clk API can handle the struct clk pointer being
616 		 * NULL.
617 		 */
618 		rtc->clk = NULL;
619 	}
620 
621 	clk_enable(rtc->clk);
622 
623 	rtc->capabilities = RTC_DEF_CAPABILITIES;
624 
625 #ifdef CONFIG_SUPERH
626 	if (dev_get_platdata(&pdev->dev)) {
627 		struct sh_rtc_platform_info *pinfo =
628 			dev_get_platdata(&pdev->dev);
629 
630 		/*
631 		 * Some CPUs have special capabilities in addition to the
632 		 * default set. Add those in here.
633 		 */
634 		rtc->capabilities |= pinfo->capabilities;
635 	}
636 #endif
637 
638 	if (rtc->carry_irq <= 0) {
639 		/* register shared periodic/carry/alarm irq */
640 		ret = devm_request_irq(&pdev->dev, rtc->periodic_irq,
641 				sh_rtc_shared, 0, "sh-rtc", rtc);
642 		if (unlikely(ret)) {
643 			dev_err(&pdev->dev,
644 				"request IRQ failed with %d, IRQ %d\n", ret,
645 				rtc->periodic_irq);
646 			goto err_unmap;
647 		}
648 	} else {
649 		/* register periodic/carry/alarm irqs */
650 		ret = devm_request_irq(&pdev->dev, rtc->periodic_irq,
651 				sh_rtc_periodic, 0, "sh-rtc period", rtc);
652 		if (unlikely(ret)) {
653 			dev_err(&pdev->dev,
654 				"request period IRQ failed with %d, IRQ %d\n",
655 				ret, rtc->periodic_irq);
656 			goto err_unmap;
657 		}
658 
659 		ret = devm_request_irq(&pdev->dev, rtc->carry_irq,
660 				sh_rtc_interrupt, 0, "sh-rtc carry", rtc);
661 		if (unlikely(ret)) {
662 			dev_err(&pdev->dev,
663 				"request carry IRQ failed with %d, IRQ %d\n",
664 				ret, rtc->carry_irq);
665 			goto err_unmap;
666 		}
667 
668 		ret = devm_request_irq(&pdev->dev, rtc->alarm_irq,
669 				sh_rtc_alarm, 0, "sh-rtc alarm", rtc);
670 		if (unlikely(ret)) {
671 			dev_err(&pdev->dev,
672 				"request alarm IRQ failed with %d, IRQ %d\n",
673 				ret, rtc->alarm_irq);
674 			goto err_unmap;
675 		}
676 	}
677 
678 	platform_set_drvdata(pdev, rtc);
679 
680 	/* everything disabled by default */
681 	sh_rtc_irq_set_freq(&pdev->dev, 0);
682 	sh_rtc_irq_set_state(&pdev->dev, 0);
683 	sh_rtc_setaie(&pdev->dev, 0);
684 	sh_rtc_setcie(&pdev->dev, 0);
685 
686 	rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "sh",
687 					   &sh_rtc_ops, THIS_MODULE);
688 	if (IS_ERR(rtc->rtc_dev)) {
689 		ret = PTR_ERR(rtc->rtc_dev);
690 		goto err_unmap;
691 	}
692 
693 	rtc->rtc_dev->max_user_freq = 256;
694 
695 	/* reset rtc to epoch 0 if time is invalid */
696 	if (rtc_read_time(rtc->rtc_dev, &r) < 0) {
697 		rtc_time_to_tm(0, &r);
698 		rtc_set_time(rtc->rtc_dev, &r);
699 	}
700 
701 	device_init_wakeup(&pdev->dev, 1);
702 	return 0;
703 
704 err_unmap:
705 	clk_disable(rtc->clk);
706 
707 	return ret;
708 }
709 
710 static int __exit sh_rtc_remove(struct platform_device *pdev)
711 {
712 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
713 
714 	sh_rtc_irq_set_state(&pdev->dev, 0);
715 
716 	sh_rtc_setaie(&pdev->dev, 0);
717 	sh_rtc_setcie(&pdev->dev, 0);
718 
719 	clk_disable(rtc->clk);
720 
721 	return 0;
722 }
723 
724 static void sh_rtc_set_irq_wake(struct device *dev, int enabled)
725 {
726 	struct platform_device *pdev = to_platform_device(dev);
727 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
728 
729 	irq_set_irq_wake(rtc->periodic_irq, enabled);
730 
731 	if (rtc->carry_irq > 0) {
732 		irq_set_irq_wake(rtc->carry_irq, enabled);
733 		irq_set_irq_wake(rtc->alarm_irq, enabled);
734 	}
735 }
736 
737 static int __maybe_unused sh_rtc_suspend(struct device *dev)
738 {
739 	if (device_may_wakeup(dev))
740 		sh_rtc_set_irq_wake(dev, 1);
741 
742 	return 0;
743 }
744 
745 static int __maybe_unused sh_rtc_resume(struct device *dev)
746 {
747 	if (device_may_wakeup(dev))
748 		sh_rtc_set_irq_wake(dev, 0);
749 
750 	return 0;
751 }
752 
753 static SIMPLE_DEV_PM_OPS(sh_rtc_pm_ops, sh_rtc_suspend, sh_rtc_resume);
754 
755 static const struct of_device_id sh_rtc_of_match[] = {
756 	{ .compatible = "renesas,sh-rtc", },
757 	{ /* sentinel */ }
758 };
759 MODULE_DEVICE_TABLE(of, sh_rtc_of_match);
760 
761 static struct platform_driver sh_rtc_platform_driver = {
762 	.driver		= {
763 		.name	= DRV_NAME,
764 		.pm	= &sh_rtc_pm_ops,
765 		.of_match_table = sh_rtc_of_match,
766 	},
767 	.remove		= __exit_p(sh_rtc_remove),
768 };
769 
770 module_platform_driver_probe(sh_rtc_platform_driver, sh_rtc_probe);
771 
772 MODULE_DESCRIPTION("SuperH on-chip RTC driver");
773 MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, "
774 	      "Jamie Lenehan <lenehan@twibble.org>, "
775 	      "Angelo Castello <angelo.castello@st.com>");
776 MODULE_LICENSE("GPL");
777 MODULE_ALIAS("platform:" DRV_NAME);
778