xref: /linux/drivers/rtc/rtc-sh.c (revision 76496f8f2e104b8bb08db09c063a6817d18829a6)
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_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
348 {
349 	struct sh_rtc *rtc = dev_get_drvdata(dev);
350 	unsigned int ret = 0;
351 
352 	switch (cmd) {
353 	case RTC_AIE_OFF:
354 	case RTC_AIE_ON:
355 		sh_rtc_setaie(dev, cmd == RTC_AIE_ON);
356 		break;
357 	case RTC_UIE_OFF:
358 		rtc->periodic_freq &= ~PF_OXS;
359 		sh_rtc_setcie(dev, 0);
360 		break;
361 	case RTC_UIE_ON:
362 		rtc->periodic_freq |= PF_OXS;
363 		sh_rtc_setcie(dev, 1);
364 		break;
365 	default:
366 		ret = -ENOIOCTLCMD;
367 	}
368 
369 	return ret;
370 }
371 
372 static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm)
373 {
374 	struct platform_device *pdev = to_platform_device(dev);
375 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
376 	unsigned int sec128, sec2, yr, yr100, cf_bit;
377 
378 	do {
379 		unsigned int tmp;
380 
381 		spin_lock_irq(&rtc->lock);
382 
383 		tmp = readb(rtc->regbase + RCR1);
384 		tmp &= ~RCR1_CF; /* Clear CF-bit */
385 		tmp |= RCR1_CIE;
386 		writeb(tmp, rtc->regbase + RCR1);
387 
388 		sec128 = readb(rtc->regbase + R64CNT);
389 
390 		tm->tm_sec	= bcd2bin(readb(rtc->regbase + RSECCNT));
391 		tm->tm_min	= bcd2bin(readb(rtc->regbase + RMINCNT));
392 		tm->tm_hour	= bcd2bin(readb(rtc->regbase + RHRCNT));
393 		tm->tm_wday	= bcd2bin(readb(rtc->regbase + RWKCNT));
394 		tm->tm_mday	= bcd2bin(readb(rtc->regbase + RDAYCNT));
395 		tm->tm_mon	= bcd2bin(readb(rtc->regbase + RMONCNT)) - 1;
396 
397 		if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
398 			yr  = readw(rtc->regbase + RYRCNT);
399 			yr100 = bcd2bin(yr >> 8);
400 			yr &= 0xff;
401 		} else {
402 			yr  = readb(rtc->regbase + RYRCNT);
403 			yr100 = bcd2bin((yr == 0x99) ? 0x19 : 0x20);
404 		}
405 
406 		tm->tm_year = (yr100 * 100 + bcd2bin(yr)) - 1900;
407 
408 		sec2 = readb(rtc->regbase + R64CNT);
409 		cf_bit = readb(rtc->regbase + RCR1) & RCR1_CF;
410 
411 		spin_unlock_irq(&rtc->lock);
412 	} while (cf_bit != 0 || ((sec128 ^ sec2) & RTC_BIT_INVERTED) != 0);
413 
414 #if RTC_BIT_INVERTED != 0
415 	if ((sec128 & RTC_BIT_INVERTED))
416 		tm->tm_sec--;
417 #endif
418 
419 	/* only keep the carry interrupt enabled if UIE is on */
420 	if (!(rtc->periodic_freq & PF_OXS))
421 		sh_rtc_setcie(dev, 0);
422 
423 	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
424 		"mday=%d, mon=%d, year=%d, wday=%d\n",
425 		__func__,
426 		tm->tm_sec, tm->tm_min, tm->tm_hour,
427 		tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
428 
429 	return rtc_valid_tm(tm);
430 }
431 
432 static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm)
433 {
434 	struct platform_device *pdev = to_platform_device(dev);
435 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
436 	unsigned int tmp;
437 	int year;
438 
439 	spin_lock_irq(&rtc->lock);
440 
441 	/* Reset pre-scaler & stop RTC */
442 	tmp = readb(rtc->regbase + RCR2);
443 	tmp |= RCR2_RESET;
444 	tmp &= ~RCR2_START;
445 	writeb(tmp, rtc->regbase + RCR2);
446 
447 	writeb(bin2bcd(tm->tm_sec),  rtc->regbase + RSECCNT);
448 	writeb(bin2bcd(tm->tm_min),  rtc->regbase + RMINCNT);
449 	writeb(bin2bcd(tm->tm_hour), rtc->regbase + RHRCNT);
450 	writeb(bin2bcd(tm->tm_wday), rtc->regbase + RWKCNT);
451 	writeb(bin2bcd(tm->tm_mday), rtc->regbase + RDAYCNT);
452 	writeb(bin2bcd(tm->tm_mon + 1), rtc->regbase + RMONCNT);
453 
454 	if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
455 		year = (bin2bcd((tm->tm_year + 1900) / 100) << 8) |
456 			bin2bcd(tm->tm_year % 100);
457 		writew(year, rtc->regbase + RYRCNT);
458 	} else {
459 		year = tm->tm_year % 100;
460 		writeb(bin2bcd(year), rtc->regbase + RYRCNT);
461 	}
462 
463 	/* Start RTC */
464 	tmp = readb(rtc->regbase + RCR2);
465 	tmp &= ~RCR2_RESET;
466 	tmp |= RCR2_RTCEN | RCR2_START;
467 	writeb(tmp, rtc->regbase + RCR2);
468 
469 	spin_unlock_irq(&rtc->lock);
470 
471 	return 0;
472 }
473 
474 static inline int sh_rtc_read_alarm_value(struct sh_rtc *rtc, int reg_off)
475 {
476 	unsigned int byte;
477 	int value = 0xff;	/* return 0xff for ignored values */
478 
479 	byte = readb(rtc->regbase + reg_off);
480 	if (byte & AR_ENB) {
481 		byte &= ~AR_ENB;	/* strip the enable bit */
482 		value = bcd2bin(byte);
483 	}
484 
485 	return value;
486 }
487 
488 static int sh_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
489 {
490 	struct platform_device *pdev = to_platform_device(dev);
491 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
492 	struct rtc_time *tm = &wkalrm->time;
493 
494 	spin_lock_irq(&rtc->lock);
495 
496 	tm->tm_sec	= sh_rtc_read_alarm_value(rtc, RSECAR);
497 	tm->tm_min	= sh_rtc_read_alarm_value(rtc, RMINAR);
498 	tm->tm_hour	= sh_rtc_read_alarm_value(rtc, RHRAR);
499 	tm->tm_wday	= sh_rtc_read_alarm_value(rtc, RWKAR);
500 	tm->tm_mday	= sh_rtc_read_alarm_value(rtc, RDAYAR);
501 	tm->tm_mon	= sh_rtc_read_alarm_value(rtc, RMONAR);
502 	if (tm->tm_mon > 0)
503 		tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */
504 	tm->tm_year     = 0xffff;
505 
506 	wkalrm->enabled = (readb(rtc->regbase + RCR1) & RCR1_AIE) ? 1 : 0;
507 
508 	spin_unlock_irq(&rtc->lock);
509 
510 	return 0;
511 }
512 
513 static inline void sh_rtc_write_alarm_value(struct sh_rtc *rtc,
514 					    int value, int reg_off)
515 {
516 	/* < 0 for a value that is ignored */
517 	if (value < 0)
518 		writeb(0, rtc->regbase + reg_off);
519 	else
520 		writeb(bin2bcd(value) | AR_ENB,  rtc->regbase + reg_off);
521 }
522 
523 static int sh_rtc_check_alarm(struct rtc_time *tm)
524 {
525 	/*
526 	 * The original rtc says anything > 0xc0 is "don't care" or "match
527 	 * all" - most users use 0xff but rtc-dev uses -1 for the same thing.
528 	 * The original rtc doesn't support years - some things use -1 and
529 	 * some 0xffff. We use -1 to make out tests easier.
530 	 */
531 	if (tm->tm_year == 0xffff)
532 		tm->tm_year = -1;
533 	if (tm->tm_mon >= 0xff)
534 		tm->tm_mon = -1;
535 	if (tm->tm_mday >= 0xff)
536 		tm->tm_mday = -1;
537 	if (tm->tm_wday >= 0xff)
538 		tm->tm_wday = -1;
539 	if (tm->tm_hour >= 0xff)
540 		tm->tm_hour = -1;
541 	if (tm->tm_min >= 0xff)
542 		tm->tm_min = -1;
543 	if (tm->tm_sec >= 0xff)
544 		tm->tm_sec = -1;
545 
546 	if (tm->tm_year > 9999 ||
547 		tm->tm_mon >= 12 ||
548 		tm->tm_mday == 0 || tm->tm_mday >= 32 ||
549 		tm->tm_wday >= 7 ||
550 		tm->tm_hour >= 24 ||
551 		tm->tm_min >= 60 ||
552 		tm->tm_sec >= 60)
553 		return -EINVAL;
554 
555 	return 0;
556 }
557 
558 static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
559 {
560 	struct platform_device *pdev = to_platform_device(dev);
561 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
562 	unsigned int rcr1;
563 	struct rtc_time *tm = &wkalrm->time;
564 	int mon, err;
565 
566 	err = sh_rtc_check_alarm(tm);
567 	if (unlikely(err < 0))
568 		return err;
569 
570 	spin_lock_irq(&rtc->lock);
571 
572 	/* disable alarm interrupt and clear the alarm flag */
573 	rcr1 = readb(rtc->regbase + RCR1);
574 	rcr1 &= ~(RCR1_AF | RCR1_AIE);
575 	writeb(rcr1, rtc->regbase + RCR1);
576 
577 	/* set alarm time */
578 	sh_rtc_write_alarm_value(rtc, tm->tm_sec,  RSECAR);
579 	sh_rtc_write_alarm_value(rtc, tm->tm_min,  RMINAR);
580 	sh_rtc_write_alarm_value(rtc, tm->tm_hour, RHRAR);
581 	sh_rtc_write_alarm_value(rtc, tm->tm_wday, RWKAR);
582 	sh_rtc_write_alarm_value(rtc, tm->tm_mday, RDAYAR);
583 	mon = tm->tm_mon;
584 	if (mon >= 0)
585 		mon += 1;
586 	sh_rtc_write_alarm_value(rtc, mon, RMONAR);
587 
588 	if (wkalrm->enabled) {
589 		rcr1 |= RCR1_AIE;
590 		writeb(rcr1, rtc->regbase + RCR1);
591 	}
592 
593 	spin_unlock_irq(&rtc->lock);
594 
595 	return 0;
596 }
597 
598 static struct rtc_class_ops sh_rtc_ops = {
599 	.ioctl		= sh_rtc_ioctl,
600 	.read_time	= sh_rtc_read_time,
601 	.set_time	= sh_rtc_set_time,
602 	.read_alarm	= sh_rtc_read_alarm,
603 	.set_alarm	= sh_rtc_set_alarm,
604 	.irq_set_state	= sh_rtc_irq_set_state,
605 	.irq_set_freq	= sh_rtc_irq_set_freq,
606 	.proc		= sh_rtc_proc,
607 };
608 
609 static int __init sh_rtc_probe(struct platform_device *pdev)
610 {
611 	struct sh_rtc *rtc;
612 	struct resource *res;
613 	struct rtc_time r;
614 	char clk_name[6];
615 	int clk_id, ret;
616 
617 	rtc = kzalloc(sizeof(struct sh_rtc), GFP_KERNEL);
618 	if (unlikely(!rtc))
619 		return -ENOMEM;
620 
621 	spin_lock_init(&rtc->lock);
622 
623 	/* get periodic/carry/alarm irqs */
624 	ret = platform_get_irq(pdev, 0);
625 	if (unlikely(ret <= 0)) {
626 		ret = -ENOENT;
627 		dev_err(&pdev->dev, "No IRQ resource\n");
628 		goto err_badres;
629 	}
630 
631 	rtc->periodic_irq = ret;
632 	rtc->carry_irq = platform_get_irq(pdev, 1);
633 	rtc->alarm_irq = platform_get_irq(pdev, 2);
634 
635 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
636 	if (unlikely(res == NULL)) {
637 		ret = -ENOENT;
638 		dev_err(&pdev->dev, "No IO resource\n");
639 		goto err_badres;
640 	}
641 
642 	rtc->regsize = resource_size(res);
643 
644 	rtc->res = request_mem_region(res->start, rtc->regsize, pdev->name);
645 	if (unlikely(!rtc->res)) {
646 		ret = -EBUSY;
647 		goto err_badres;
648 	}
649 
650 	rtc->regbase = ioremap_nocache(rtc->res->start, rtc->regsize);
651 	if (unlikely(!rtc->regbase)) {
652 		ret = -EINVAL;
653 		goto err_badmap;
654 	}
655 
656 	clk_id = pdev->id;
657 	/* With a single device, the clock id is still "rtc0" */
658 	if (clk_id < 0)
659 		clk_id = 0;
660 
661 	snprintf(clk_name, sizeof(clk_name), "rtc%d", clk_id);
662 
663 	rtc->clk = clk_get(&pdev->dev, clk_name);
664 	if (IS_ERR(rtc->clk)) {
665 		/*
666 		 * No error handling for rtc->clk intentionally, not all
667 		 * platforms will have a unique clock for the RTC, and
668 		 * the clk API can handle the struct clk pointer being
669 		 * NULL.
670 		 */
671 		rtc->clk = NULL;
672 	}
673 
674 	clk_enable(rtc->clk);
675 
676 	rtc->capabilities = RTC_DEF_CAPABILITIES;
677 	if (pdev->dev.platform_data) {
678 		struct sh_rtc_platform_info *pinfo = pdev->dev.platform_data;
679 
680 		/*
681 		 * Some CPUs have special capabilities in addition to the
682 		 * default set. Add those in here.
683 		 */
684 		rtc->capabilities |= pinfo->capabilities;
685 	}
686 
687 	if (rtc->carry_irq <= 0) {
688 		/* register shared periodic/carry/alarm irq */
689 		ret = request_irq(rtc->periodic_irq, sh_rtc_shared,
690 				  IRQF_DISABLED, "sh-rtc", rtc);
691 		if (unlikely(ret)) {
692 			dev_err(&pdev->dev,
693 				"request IRQ failed with %d, IRQ %d\n", ret,
694 				rtc->periodic_irq);
695 			goto err_unmap;
696 		}
697 	} else {
698 		/* register periodic/carry/alarm irqs */
699 		ret = request_irq(rtc->periodic_irq, sh_rtc_periodic,
700 				  IRQF_DISABLED, "sh-rtc period", rtc);
701 		if (unlikely(ret)) {
702 			dev_err(&pdev->dev,
703 				"request period IRQ failed with %d, IRQ %d\n",
704 				ret, rtc->periodic_irq);
705 			goto err_unmap;
706 		}
707 
708 		ret = request_irq(rtc->carry_irq, sh_rtc_interrupt,
709 				  IRQF_DISABLED, "sh-rtc carry", rtc);
710 		if (unlikely(ret)) {
711 			dev_err(&pdev->dev,
712 				"request carry IRQ failed with %d, IRQ %d\n",
713 				ret, rtc->carry_irq);
714 			free_irq(rtc->periodic_irq, rtc);
715 			goto err_unmap;
716 		}
717 
718 		ret = request_irq(rtc->alarm_irq, sh_rtc_alarm,
719 				  IRQF_DISABLED, "sh-rtc alarm", rtc);
720 		if (unlikely(ret)) {
721 			dev_err(&pdev->dev,
722 				"request alarm IRQ failed with %d, IRQ %d\n",
723 				ret, rtc->alarm_irq);
724 			free_irq(rtc->carry_irq, rtc);
725 			free_irq(rtc->periodic_irq, rtc);
726 			goto err_unmap;
727 		}
728 	}
729 
730 	platform_set_drvdata(pdev, rtc);
731 
732 	/* everything disabled by default */
733 	sh_rtc_irq_set_freq(&pdev->dev, 0);
734 	sh_rtc_irq_set_state(&pdev->dev, 0);
735 	sh_rtc_setaie(&pdev->dev, 0);
736 	sh_rtc_setcie(&pdev->dev, 0);
737 
738 	rtc->rtc_dev = rtc_device_register("sh", &pdev->dev,
739 					   &sh_rtc_ops, THIS_MODULE);
740 	if (IS_ERR(rtc->rtc_dev)) {
741 		ret = PTR_ERR(rtc->rtc_dev);
742 		free_irq(rtc->periodic_irq, rtc);
743 		free_irq(rtc->carry_irq, rtc);
744 		free_irq(rtc->alarm_irq, rtc);
745 		goto err_unmap;
746 	}
747 
748 	rtc->rtc_dev->max_user_freq = 256;
749 
750 	/* reset rtc to epoch 0 if time is invalid */
751 	if (rtc_read_time(rtc->rtc_dev, &r) < 0) {
752 		rtc_time_to_tm(0, &r);
753 		rtc_set_time(rtc->rtc_dev, &r);
754 	}
755 
756 	device_init_wakeup(&pdev->dev, 1);
757 	return 0;
758 
759 err_unmap:
760 	clk_disable(rtc->clk);
761 	clk_put(rtc->clk);
762 	iounmap(rtc->regbase);
763 err_badmap:
764 	release_mem_region(rtc->res->start, rtc->regsize);
765 err_badres:
766 	kfree(rtc);
767 
768 	return ret;
769 }
770 
771 static int __exit sh_rtc_remove(struct platform_device *pdev)
772 {
773 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
774 
775 	rtc_device_unregister(rtc->rtc_dev);
776 	sh_rtc_irq_set_state(&pdev->dev, 0);
777 
778 	sh_rtc_setaie(&pdev->dev, 0);
779 	sh_rtc_setcie(&pdev->dev, 0);
780 
781 	free_irq(rtc->periodic_irq, rtc);
782 
783 	if (rtc->carry_irq > 0) {
784 		free_irq(rtc->carry_irq, rtc);
785 		free_irq(rtc->alarm_irq, rtc);
786 	}
787 
788 	iounmap(rtc->regbase);
789 	release_mem_region(rtc->res->start, rtc->regsize);
790 
791 	clk_disable(rtc->clk);
792 	clk_put(rtc->clk);
793 
794 	platform_set_drvdata(pdev, NULL);
795 
796 	kfree(rtc);
797 
798 	return 0;
799 }
800 
801 static void sh_rtc_set_irq_wake(struct device *dev, int enabled)
802 {
803 	struct platform_device *pdev = to_platform_device(dev);
804 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
805 
806 	set_irq_wake(rtc->periodic_irq, enabled);
807 
808 	if (rtc->carry_irq > 0) {
809 		set_irq_wake(rtc->carry_irq, enabled);
810 		set_irq_wake(rtc->alarm_irq, enabled);
811 	}
812 }
813 
814 static int sh_rtc_suspend(struct device *dev)
815 {
816 	if (device_may_wakeup(dev))
817 		sh_rtc_set_irq_wake(dev, 1);
818 
819 	return 0;
820 }
821 
822 static int sh_rtc_resume(struct device *dev)
823 {
824 	if (device_may_wakeup(dev))
825 		sh_rtc_set_irq_wake(dev, 0);
826 
827 	return 0;
828 }
829 
830 static const struct dev_pm_ops sh_rtc_dev_pm_ops = {
831 	.suspend = sh_rtc_suspend,
832 	.resume = sh_rtc_resume,
833 };
834 
835 static struct platform_driver sh_rtc_platform_driver = {
836 	.driver		= {
837 		.name	= DRV_NAME,
838 		.owner	= THIS_MODULE,
839 		.pm	= &sh_rtc_dev_pm_ops,
840 	},
841 	.remove		= __exit_p(sh_rtc_remove),
842 };
843 
844 static int __init sh_rtc_init(void)
845 {
846 	return platform_driver_probe(&sh_rtc_platform_driver, sh_rtc_probe);
847 }
848 
849 static void __exit sh_rtc_exit(void)
850 {
851 	platform_driver_unregister(&sh_rtc_platform_driver);
852 }
853 
854 module_init(sh_rtc_init);
855 module_exit(sh_rtc_exit);
856 
857 MODULE_DESCRIPTION("SuperH on-chip RTC driver");
858 MODULE_VERSION(DRV_VERSION);
859 MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, "
860 	      "Jamie Lenehan <lenehan@twibble.org>, "
861 	      "Angelo Castello <angelo.castello@st.com>");
862 MODULE_LICENSE("GPL");
863 MODULE_ALIAS("platform:" DRV_NAME);
864