xref: /linux/drivers/rtc/rtc-sh.c (revision ac6a0cf6716bb46813d0161024c66c2af66e53d1)
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 <asm/rtc.h>
30 
31 #define DRV_NAME	"sh-rtc"
32 #define DRV_VERSION	"0.2.3"
33 
34 #define RTC_REG(r)	((r) * rtc_reg_size)
35 
36 #define R64CNT		RTC_REG(0)
37 
38 #define RSECCNT		RTC_REG(1)	/* RTC sec */
39 #define RMINCNT		RTC_REG(2)	/* RTC min */
40 #define RHRCNT		RTC_REG(3)	/* RTC hour */
41 #define RWKCNT		RTC_REG(4)	/* RTC week */
42 #define RDAYCNT		RTC_REG(5)	/* RTC day */
43 #define RMONCNT		RTC_REG(6)	/* RTC month */
44 #define RYRCNT		RTC_REG(7)	/* RTC year */
45 #define RSECAR		RTC_REG(8)	/* ALARM sec */
46 #define RMINAR		RTC_REG(9)	/* ALARM min */
47 #define RHRAR		RTC_REG(10)	/* ALARM hour */
48 #define RWKAR		RTC_REG(11)	/* ALARM week */
49 #define RDAYAR		RTC_REG(12)	/* ALARM day */
50 #define RMONAR		RTC_REG(13)	/* ALARM month */
51 #define RCR1		RTC_REG(14)	/* Control */
52 #define RCR2		RTC_REG(15)	/* Control */
53 
54 /*
55  * Note on RYRAR and RCR3: Up until this point most of the register
56  * definitions are consistent across all of the available parts. However,
57  * the placement of the optional RYRAR and RCR3 (the RYRAR control
58  * register used to control RYRCNT/RYRAR compare) varies considerably
59  * across various parts, occasionally being mapped in to a completely
60  * unrelated address space. For proper RYRAR support a separate resource
61  * would have to be handed off, but as this is purely optional in
62  * practice, we simply opt not to support it, thereby keeping the code
63  * quite a bit more simplified.
64  */
65 
66 /* ALARM Bits - or with BCD encoded value */
67 #define AR_ENB		0x80	/* Enable for alarm cmp   */
68 
69 /* Period Bits */
70 #define PF_HP		0x100	/* Enable Half Period to support 8,32,128Hz */
71 #define PF_COUNT	0x200	/* Half periodic counter */
72 #define PF_OXS		0x400	/* Periodic One x Second */
73 #define PF_KOU		0x800	/* Kernel or User periodic request 1=kernel */
74 #define PF_MASK		0xf00
75 
76 /* RCR1 Bits */
77 #define RCR1_CF		0x80	/* Carry Flag             */
78 #define RCR1_CIE	0x10	/* Carry Interrupt Enable */
79 #define RCR1_AIE	0x08	/* Alarm Interrupt Enable */
80 #define RCR1_AF		0x01	/* Alarm Flag             */
81 
82 /* RCR2 Bits */
83 #define RCR2_PEF	0x80	/* PEriodic interrupt Flag */
84 #define RCR2_PESMASK	0x70	/* Periodic interrupt Set  */
85 #define RCR2_RTCEN	0x08	/* ENable RTC              */
86 #define RCR2_ADJ	0x04	/* ADJustment (30-second)  */
87 #define RCR2_RESET	0x02	/* Reset bit               */
88 #define RCR2_START	0x01	/* Start bit               */
89 
90 struct sh_rtc {
91 	void __iomem		*regbase;
92 	unsigned long		regsize;
93 	struct resource		*res;
94 	int			alarm_irq;
95 	int			periodic_irq;
96 	int			carry_irq;
97 	struct clk		*clk;
98 	struct rtc_device	*rtc_dev;
99 	spinlock_t		lock;
100 	unsigned long		capabilities;	/* See asm/rtc.h for cap bits */
101 	unsigned short		periodic_freq;
102 };
103 
104 static int __sh_rtc_interrupt(struct sh_rtc *rtc)
105 {
106 	unsigned int tmp, pending;
107 
108 	tmp = readb(rtc->regbase + RCR1);
109 	pending = tmp & RCR1_CF;
110 	tmp &= ~RCR1_CF;
111 	writeb(tmp, rtc->regbase + RCR1);
112 
113 	/* Users have requested One x Second IRQ */
114 	if (pending && rtc->periodic_freq & PF_OXS)
115 		rtc_update_irq(rtc->rtc_dev, 1, RTC_UF | RTC_IRQF);
116 
117 	return pending;
118 }
119 
120 static int __sh_rtc_alarm(struct sh_rtc *rtc)
121 {
122 	unsigned int tmp, pending;
123 
124 	tmp = readb(rtc->regbase + RCR1);
125 	pending = tmp & RCR1_AF;
126 	tmp &= ~(RCR1_AF | RCR1_AIE);
127 	writeb(tmp, rtc->regbase + RCR1);
128 
129 	if (pending)
130 		rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF);
131 
132 	return pending;
133 }
134 
135 static int __sh_rtc_periodic(struct sh_rtc *rtc)
136 {
137 	struct rtc_device *rtc_dev = rtc->rtc_dev;
138 	struct rtc_task *irq_task;
139 	unsigned int tmp, pending;
140 
141 	tmp = readb(rtc->regbase + RCR2);
142 	pending = tmp & RCR2_PEF;
143 	tmp &= ~RCR2_PEF;
144 	writeb(tmp, rtc->regbase + RCR2);
145 
146 	if (!pending)
147 		return 0;
148 
149 	/* Half period enabled than one skipped and the next notified */
150 	if ((rtc->periodic_freq & PF_HP) && (rtc->periodic_freq & PF_COUNT))
151 		rtc->periodic_freq &= ~PF_COUNT;
152 	else {
153 		if (rtc->periodic_freq & PF_HP)
154 			rtc->periodic_freq |= PF_COUNT;
155 		if (rtc->periodic_freq & PF_KOU) {
156 			spin_lock(&rtc_dev->irq_task_lock);
157 			irq_task = rtc_dev->irq_task;
158 			if (irq_task)
159 				irq_task->func(irq_task->private_data);
160 			spin_unlock(&rtc_dev->irq_task_lock);
161 		} else
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 int sh_rtc_irq_set_state(struct device *dev, 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 + RCR2);
226 
227 	if (enable) {
228 		rtc->periodic_freq |= PF_KOU;
229 		tmp &= ~RCR2_PEF;	/* Clear PES bit */
230 		tmp |= (rtc->periodic_freq & ~PF_HP);	/* Set PES2-0 */
231 	} else {
232 		rtc->periodic_freq &= ~PF_KOU;
233 		tmp &= ~(RCR2_PESMASK | RCR2_PEF);
234 	}
235 
236 	writeb(tmp, rtc->regbase + RCR2);
237 
238 	spin_unlock_irq(&rtc->lock);
239 
240 	return 0;
241 }
242 
243 static int sh_rtc_irq_set_freq(struct device *dev, int freq)
244 {
245 	struct sh_rtc *rtc = dev_get_drvdata(dev);
246 	int tmp, ret = 0;
247 
248 	spin_lock_irq(&rtc->lock);
249 	tmp = rtc->periodic_freq & PF_MASK;
250 
251 	switch (freq) {
252 	case 0:
253 		rtc->periodic_freq = 0x00;
254 		break;
255 	case 1:
256 		rtc->periodic_freq = 0x60;
257 		break;
258 	case 2:
259 		rtc->periodic_freq = 0x50;
260 		break;
261 	case 4:
262 		rtc->periodic_freq = 0x40;
263 		break;
264 	case 8:
265 		rtc->periodic_freq = 0x30 | PF_HP;
266 		break;
267 	case 16:
268 		rtc->periodic_freq = 0x30;
269 		break;
270 	case 32:
271 		rtc->periodic_freq = 0x20 | PF_HP;
272 		break;
273 	case 64:
274 		rtc->periodic_freq = 0x20;
275 		break;
276 	case 128:
277 		rtc->periodic_freq = 0x10 | PF_HP;
278 		break;
279 	case 256:
280 		rtc->periodic_freq = 0x10;
281 		break;
282 	default:
283 		ret = -ENOTSUPP;
284 	}
285 
286 	if (ret == 0) {
287 		rtc->periodic_freq |= tmp;
288 		rtc->rtc_dev->irq_freq = freq;
289 	}
290 
291 	spin_unlock_irq(&rtc->lock);
292 	return ret;
293 }
294 
295 static inline void sh_rtc_setaie(struct device *dev, unsigned int enable)
296 {
297 	struct sh_rtc *rtc = dev_get_drvdata(dev);
298 	unsigned int tmp;
299 
300 	spin_lock_irq(&rtc->lock);
301 
302 	tmp = readb(rtc->regbase + RCR1);
303 
304 	if (enable)
305 		tmp |= RCR1_AIE;
306 	else
307 		tmp &= ~RCR1_AIE;
308 
309 	writeb(tmp, rtc->regbase + RCR1);
310 
311 	spin_unlock_irq(&rtc->lock);
312 }
313 
314 static int sh_rtc_proc(struct device *dev, struct seq_file *seq)
315 {
316 	struct sh_rtc *rtc = dev_get_drvdata(dev);
317 	unsigned int tmp;
318 
319 	tmp = readb(rtc->regbase + RCR1);
320 	seq_printf(seq, "carry_IRQ\t: %s\n", (tmp & RCR1_CIE) ? "yes" : "no");
321 
322 	tmp = readb(rtc->regbase + RCR2);
323 	seq_printf(seq, "periodic_IRQ\t: %s\n",
324 		   (tmp & RCR2_PESMASK) ? "yes" : "no");
325 
326 	return 0;
327 }
328 
329 static inline void sh_rtc_setcie(struct device *dev, unsigned int enable)
330 {
331 	struct sh_rtc *rtc = dev_get_drvdata(dev);
332 	unsigned int tmp;
333 
334 	spin_lock_irq(&rtc->lock);
335 
336 	tmp = readb(rtc->regbase + RCR1);
337 
338 	if (!enable)
339 		tmp &= ~RCR1_CIE;
340 	else
341 		tmp |= RCR1_CIE;
342 
343 	writeb(tmp, rtc->regbase + RCR1);
344 
345 	spin_unlock_irq(&rtc->lock);
346 }
347 
348 static int sh_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
349 {
350 	struct sh_rtc *rtc = dev_get_drvdata(dev);
351 	unsigned int ret = 0;
352 
353 	switch (cmd) {
354 	case RTC_AIE_OFF:
355 	case RTC_AIE_ON:
356 		sh_rtc_setaie(dev, cmd == RTC_AIE_ON);
357 		break;
358 	case RTC_UIE_OFF:
359 		rtc->periodic_freq &= ~PF_OXS;
360 		sh_rtc_setcie(dev, 0);
361 		break;
362 	case RTC_UIE_ON:
363 		rtc->periodic_freq |= PF_OXS;
364 		sh_rtc_setcie(dev, 1);
365 		break;
366 	default:
367 		ret = -ENOIOCTLCMD;
368 	}
369 
370 	return ret;
371 }
372 
373 static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm)
374 {
375 	struct platform_device *pdev = to_platform_device(dev);
376 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
377 	unsigned int sec128, sec2, yr, yr100, cf_bit;
378 
379 	do {
380 		unsigned int tmp;
381 
382 		spin_lock_irq(&rtc->lock);
383 
384 		tmp = readb(rtc->regbase + RCR1);
385 		tmp &= ~RCR1_CF; /* Clear CF-bit */
386 		tmp |= RCR1_CIE;
387 		writeb(tmp, rtc->regbase + RCR1);
388 
389 		sec128 = readb(rtc->regbase + R64CNT);
390 
391 		tm->tm_sec	= bcd2bin(readb(rtc->regbase + RSECCNT));
392 		tm->tm_min	= bcd2bin(readb(rtc->regbase + RMINCNT));
393 		tm->tm_hour	= bcd2bin(readb(rtc->regbase + RHRCNT));
394 		tm->tm_wday	= bcd2bin(readb(rtc->regbase + RWKCNT));
395 		tm->tm_mday	= bcd2bin(readb(rtc->regbase + RDAYCNT));
396 		tm->tm_mon	= bcd2bin(readb(rtc->regbase + RMONCNT)) - 1;
397 
398 		if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
399 			yr  = readw(rtc->regbase + RYRCNT);
400 			yr100 = bcd2bin(yr >> 8);
401 			yr &= 0xff;
402 		} else {
403 			yr  = readb(rtc->regbase + RYRCNT);
404 			yr100 = bcd2bin((yr == 0x99) ? 0x19 : 0x20);
405 		}
406 
407 		tm->tm_year = (yr100 * 100 + bcd2bin(yr)) - 1900;
408 
409 		sec2 = readb(rtc->regbase + R64CNT);
410 		cf_bit = readb(rtc->regbase + RCR1) & RCR1_CF;
411 
412 		spin_unlock_irq(&rtc->lock);
413 	} while (cf_bit != 0 || ((sec128 ^ sec2) & RTC_BIT_INVERTED) != 0);
414 
415 #if RTC_BIT_INVERTED != 0
416 	if ((sec128 & RTC_BIT_INVERTED))
417 		tm->tm_sec--;
418 #endif
419 
420 	/* only keep the carry interrupt enabled if UIE is on */
421 	if (!(rtc->periodic_freq & PF_OXS))
422 		sh_rtc_setcie(dev, 0);
423 
424 	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
425 		"mday=%d, mon=%d, year=%d, wday=%d\n",
426 		__func__,
427 		tm->tm_sec, tm->tm_min, tm->tm_hour,
428 		tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
429 
430 	return rtc_valid_tm(tm);
431 }
432 
433 static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm)
434 {
435 	struct platform_device *pdev = to_platform_device(dev);
436 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
437 	unsigned int tmp;
438 	int year;
439 
440 	spin_lock_irq(&rtc->lock);
441 
442 	/* Reset pre-scaler & stop RTC */
443 	tmp = readb(rtc->regbase + RCR2);
444 	tmp |= RCR2_RESET;
445 	tmp &= ~RCR2_START;
446 	writeb(tmp, rtc->regbase + RCR2);
447 
448 	writeb(bin2bcd(tm->tm_sec),  rtc->regbase + RSECCNT);
449 	writeb(bin2bcd(tm->tm_min),  rtc->regbase + RMINCNT);
450 	writeb(bin2bcd(tm->tm_hour), rtc->regbase + RHRCNT);
451 	writeb(bin2bcd(tm->tm_wday), rtc->regbase + RWKCNT);
452 	writeb(bin2bcd(tm->tm_mday), rtc->regbase + RDAYCNT);
453 	writeb(bin2bcd(tm->tm_mon + 1), rtc->regbase + RMONCNT);
454 
455 	if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
456 		year = (bin2bcd((tm->tm_year + 1900) / 100) << 8) |
457 			bin2bcd(tm->tm_year % 100);
458 		writew(year, rtc->regbase + RYRCNT);
459 	} else {
460 		year = tm->tm_year % 100;
461 		writeb(bin2bcd(year), rtc->regbase + RYRCNT);
462 	}
463 
464 	/* Start RTC */
465 	tmp = readb(rtc->regbase + RCR2);
466 	tmp &= ~RCR2_RESET;
467 	tmp |= RCR2_RTCEN | RCR2_START;
468 	writeb(tmp, rtc->regbase + RCR2);
469 
470 	spin_unlock_irq(&rtc->lock);
471 
472 	return 0;
473 }
474 
475 static inline int sh_rtc_read_alarm_value(struct sh_rtc *rtc, int reg_off)
476 {
477 	unsigned int byte;
478 	int value = 0xff;	/* return 0xff for ignored values */
479 
480 	byte = readb(rtc->regbase + reg_off);
481 	if (byte & AR_ENB) {
482 		byte &= ~AR_ENB;	/* strip the enable bit */
483 		value = bcd2bin(byte);
484 	}
485 
486 	return value;
487 }
488 
489 static int sh_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
490 {
491 	struct platform_device *pdev = to_platform_device(dev);
492 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
493 	struct rtc_time *tm = &wkalrm->time;
494 
495 	spin_lock_irq(&rtc->lock);
496 
497 	tm->tm_sec	= sh_rtc_read_alarm_value(rtc, RSECAR);
498 	tm->tm_min	= sh_rtc_read_alarm_value(rtc, RMINAR);
499 	tm->tm_hour	= sh_rtc_read_alarm_value(rtc, RHRAR);
500 	tm->tm_wday	= sh_rtc_read_alarm_value(rtc, RWKAR);
501 	tm->tm_mday	= sh_rtc_read_alarm_value(rtc, RDAYAR);
502 	tm->tm_mon	= sh_rtc_read_alarm_value(rtc, RMONAR);
503 	if (tm->tm_mon > 0)
504 		tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */
505 	tm->tm_year     = 0xffff;
506 
507 	wkalrm->enabled = (readb(rtc->regbase + RCR1) & RCR1_AIE) ? 1 : 0;
508 
509 	spin_unlock_irq(&rtc->lock);
510 
511 	return 0;
512 }
513 
514 static inline void sh_rtc_write_alarm_value(struct sh_rtc *rtc,
515 					    int value, int reg_off)
516 {
517 	/* < 0 for a value that is ignored */
518 	if (value < 0)
519 		writeb(0, rtc->regbase + reg_off);
520 	else
521 		writeb(bin2bcd(value) | AR_ENB,  rtc->regbase + reg_off);
522 }
523 
524 static int sh_rtc_check_alarm(struct rtc_time *tm)
525 {
526 	/*
527 	 * The original rtc says anything > 0xc0 is "don't care" or "match
528 	 * all" - most users use 0xff but rtc-dev uses -1 for the same thing.
529 	 * The original rtc doesn't support years - some things use -1 and
530 	 * some 0xffff. We use -1 to make out tests easier.
531 	 */
532 	if (tm->tm_year == 0xffff)
533 		tm->tm_year = -1;
534 	if (tm->tm_mon >= 0xff)
535 		tm->tm_mon = -1;
536 	if (tm->tm_mday >= 0xff)
537 		tm->tm_mday = -1;
538 	if (tm->tm_wday >= 0xff)
539 		tm->tm_wday = -1;
540 	if (tm->tm_hour >= 0xff)
541 		tm->tm_hour = -1;
542 	if (tm->tm_min >= 0xff)
543 		tm->tm_min = -1;
544 	if (tm->tm_sec >= 0xff)
545 		tm->tm_sec = -1;
546 
547 	if (tm->tm_year > 9999 ||
548 		tm->tm_mon >= 12 ||
549 		tm->tm_mday == 0 || tm->tm_mday >= 32 ||
550 		tm->tm_wday >= 7 ||
551 		tm->tm_hour >= 24 ||
552 		tm->tm_min >= 60 ||
553 		tm->tm_sec >= 60)
554 		return -EINVAL;
555 
556 	return 0;
557 }
558 
559 static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
560 {
561 	struct platform_device *pdev = to_platform_device(dev);
562 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
563 	unsigned int rcr1;
564 	struct rtc_time *tm = &wkalrm->time;
565 	int mon, err;
566 
567 	err = sh_rtc_check_alarm(tm);
568 	if (unlikely(err < 0))
569 		return err;
570 
571 	spin_lock_irq(&rtc->lock);
572 
573 	/* disable alarm interrupt and clear the alarm flag */
574 	rcr1 = readb(rtc->regbase + RCR1);
575 	rcr1 &= ~(RCR1_AF | RCR1_AIE);
576 	writeb(rcr1, rtc->regbase + RCR1);
577 
578 	/* set alarm time */
579 	sh_rtc_write_alarm_value(rtc, tm->tm_sec,  RSECAR);
580 	sh_rtc_write_alarm_value(rtc, tm->tm_min,  RMINAR);
581 	sh_rtc_write_alarm_value(rtc, tm->tm_hour, RHRAR);
582 	sh_rtc_write_alarm_value(rtc, tm->tm_wday, RWKAR);
583 	sh_rtc_write_alarm_value(rtc, tm->tm_mday, RDAYAR);
584 	mon = tm->tm_mon;
585 	if (mon >= 0)
586 		mon += 1;
587 	sh_rtc_write_alarm_value(rtc, mon, RMONAR);
588 
589 	if (wkalrm->enabled) {
590 		rcr1 |= RCR1_AIE;
591 		writeb(rcr1, rtc->regbase + RCR1);
592 	}
593 
594 	spin_unlock_irq(&rtc->lock);
595 
596 	return 0;
597 }
598 
599 static struct rtc_class_ops sh_rtc_ops = {
600 	.ioctl		= sh_rtc_ioctl,
601 	.read_time	= sh_rtc_read_time,
602 	.set_time	= sh_rtc_set_time,
603 	.read_alarm	= sh_rtc_read_alarm,
604 	.set_alarm	= sh_rtc_set_alarm,
605 	.irq_set_state	= sh_rtc_irq_set_state,
606 	.irq_set_freq	= sh_rtc_irq_set_freq,
607 	.proc		= sh_rtc_proc,
608 };
609 
610 static int __init sh_rtc_probe(struct platform_device *pdev)
611 {
612 	struct sh_rtc *rtc;
613 	struct resource *res;
614 	struct rtc_time r;
615 	char clk_name[6];
616 	int clk_id, ret;
617 
618 	rtc = kzalloc(sizeof(struct sh_rtc), GFP_KERNEL);
619 	if (unlikely(!rtc))
620 		return -ENOMEM;
621 
622 	spin_lock_init(&rtc->lock);
623 
624 	/* get periodic/carry/alarm irqs */
625 	ret = platform_get_irq(pdev, 0);
626 	if (unlikely(ret <= 0)) {
627 		ret = -ENOENT;
628 		dev_err(&pdev->dev, "No IRQ resource\n");
629 		goto err_badres;
630 	}
631 
632 	rtc->periodic_irq = ret;
633 	rtc->carry_irq = platform_get_irq(pdev, 1);
634 	rtc->alarm_irq = platform_get_irq(pdev, 2);
635 
636 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
637 	if (unlikely(res == NULL)) {
638 		ret = -ENOENT;
639 		dev_err(&pdev->dev, "No IO resource\n");
640 		goto err_badres;
641 	}
642 
643 	rtc->regsize = resource_size(res);
644 
645 	rtc->res = request_mem_region(res->start, rtc->regsize, pdev->name);
646 	if (unlikely(!rtc->res)) {
647 		ret = -EBUSY;
648 		goto err_badres;
649 	}
650 
651 	rtc->regbase = ioremap_nocache(rtc->res->start, rtc->regsize);
652 	if (unlikely(!rtc->regbase)) {
653 		ret = -EINVAL;
654 		goto err_badmap;
655 	}
656 
657 	clk_id = pdev->id;
658 	/* With a single device, the clock id is still "rtc0" */
659 	if (clk_id < 0)
660 		clk_id = 0;
661 
662 	snprintf(clk_name, sizeof(clk_name), "rtc%d", clk_id);
663 
664 	rtc->clk = clk_get(&pdev->dev, clk_name);
665 	if (IS_ERR(rtc->clk)) {
666 		/*
667 		 * No error handling for rtc->clk intentionally, not all
668 		 * platforms will have a unique clock for the RTC, and
669 		 * the clk API can handle the struct clk pointer being
670 		 * NULL.
671 		 */
672 		rtc->clk = NULL;
673 	}
674 
675 	clk_enable(rtc->clk);
676 
677 	rtc->capabilities = RTC_DEF_CAPABILITIES;
678 	if (pdev->dev.platform_data) {
679 		struct sh_rtc_platform_info *pinfo = pdev->dev.platform_data;
680 
681 		/*
682 		 * Some CPUs have special capabilities in addition to the
683 		 * default set. Add those in here.
684 		 */
685 		rtc->capabilities |= pinfo->capabilities;
686 	}
687 
688 	if (rtc->carry_irq <= 0) {
689 		/* register shared periodic/carry/alarm irq */
690 		ret = request_irq(rtc->periodic_irq, sh_rtc_shared,
691 				  IRQF_DISABLED, "sh-rtc", rtc);
692 		if (unlikely(ret)) {
693 			dev_err(&pdev->dev,
694 				"request IRQ failed with %d, IRQ %d\n", ret,
695 				rtc->periodic_irq);
696 			goto err_unmap;
697 		}
698 	} else {
699 		/* register periodic/carry/alarm irqs */
700 		ret = request_irq(rtc->periodic_irq, sh_rtc_periodic,
701 				  IRQF_DISABLED, "sh-rtc period", rtc);
702 		if (unlikely(ret)) {
703 			dev_err(&pdev->dev,
704 				"request period IRQ failed with %d, IRQ %d\n",
705 				ret, rtc->periodic_irq);
706 			goto err_unmap;
707 		}
708 
709 		ret = request_irq(rtc->carry_irq, sh_rtc_interrupt,
710 				  IRQF_DISABLED, "sh-rtc carry", rtc);
711 		if (unlikely(ret)) {
712 			dev_err(&pdev->dev,
713 				"request carry IRQ failed with %d, IRQ %d\n",
714 				ret, rtc->carry_irq);
715 			free_irq(rtc->periodic_irq, rtc);
716 			goto err_unmap;
717 		}
718 
719 		ret = request_irq(rtc->alarm_irq, sh_rtc_alarm,
720 				  IRQF_DISABLED, "sh-rtc alarm", rtc);
721 		if (unlikely(ret)) {
722 			dev_err(&pdev->dev,
723 				"request alarm IRQ failed with %d, IRQ %d\n",
724 				ret, rtc->alarm_irq);
725 			free_irq(rtc->carry_irq, rtc);
726 			free_irq(rtc->periodic_irq, rtc);
727 			goto err_unmap;
728 		}
729 	}
730 
731 	platform_set_drvdata(pdev, rtc);
732 
733 	/* everything disabled by default */
734 	sh_rtc_irq_set_freq(&pdev->dev, 0);
735 	sh_rtc_irq_set_state(&pdev->dev, 0);
736 	sh_rtc_setaie(&pdev->dev, 0);
737 	sh_rtc_setcie(&pdev->dev, 0);
738 
739 	rtc->rtc_dev = rtc_device_register("sh", &pdev->dev,
740 					   &sh_rtc_ops, THIS_MODULE);
741 	if (IS_ERR(rtc->rtc_dev)) {
742 		ret = PTR_ERR(rtc->rtc_dev);
743 		free_irq(rtc->periodic_irq, rtc);
744 		free_irq(rtc->carry_irq, rtc);
745 		free_irq(rtc->alarm_irq, rtc);
746 		goto err_unmap;
747 	}
748 
749 	rtc->rtc_dev->max_user_freq = 256;
750 
751 	/* reset rtc to epoch 0 if time is invalid */
752 	if (rtc_read_time(rtc->rtc_dev, &r) < 0) {
753 		rtc_time_to_tm(0, &r);
754 		rtc_set_time(rtc->rtc_dev, &r);
755 	}
756 
757 	device_init_wakeup(&pdev->dev, 1);
758 	return 0;
759 
760 err_unmap:
761 	clk_disable(rtc->clk);
762 	clk_put(rtc->clk);
763 	iounmap(rtc->regbase);
764 err_badmap:
765 	release_resource(rtc->res);
766 err_badres:
767 	kfree(rtc);
768 
769 	return ret;
770 }
771 
772 static int __exit sh_rtc_remove(struct platform_device *pdev)
773 {
774 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
775 
776 	rtc_device_unregister(rtc->rtc_dev);
777 	sh_rtc_irq_set_state(&pdev->dev, 0);
778 
779 	sh_rtc_setaie(&pdev->dev, 0);
780 	sh_rtc_setcie(&pdev->dev, 0);
781 
782 	free_irq(rtc->periodic_irq, rtc);
783 
784 	if (rtc->carry_irq > 0) {
785 		free_irq(rtc->carry_irq, rtc);
786 		free_irq(rtc->alarm_irq, rtc);
787 	}
788 
789 	iounmap(rtc->regbase);
790 	release_resource(rtc->res);
791 
792 	clk_disable(rtc->clk);
793 	clk_put(rtc->clk);
794 
795 	platform_set_drvdata(pdev, NULL);
796 
797 	kfree(rtc);
798 
799 	return 0;
800 }
801 
802 static void sh_rtc_set_irq_wake(struct device *dev, int enabled)
803 {
804 	struct platform_device *pdev = to_platform_device(dev);
805 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
806 
807 	set_irq_wake(rtc->periodic_irq, enabled);
808 
809 	if (rtc->carry_irq > 0) {
810 		set_irq_wake(rtc->carry_irq, enabled);
811 		set_irq_wake(rtc->alarm_irq, enabled);
812 	}
813 }
814 
815 static int sh_rtc_suspend(struct device *dev)
816 {
817 	if (device_may_wakeup(dev))
818 		sh_rtc_set_irq_wake(dev, 1);
819 
820 	return 0;
821 }
822 
823 static int sh_rtc_resume(struct device *dev)
824 {
825 	if (device_may_wakeup(dev))
826 		sh_rtc_set_irq_wake(dev, 0);
827 
828 	return 0;
829 }
830 
831 static struct dev_pm_ops sh_rtc_dev_pm_ops = {
832 	.suspend = sh_rtc_suspend,
833 	.resume = sh_rtc_resume,
834 };
835 
836 static struct platform_driver sh_rtc_platform_driver = {
837 	.driver		= {
838 		.name	= DRV_NAME,
839 		.owner	= THIS_MODULE,
840 		.pm	= &sh_rtc_dev_pm_ops,
841 	},
842 	.remove		= __exit_p(sh_rtc_remove),
843 };
844 
845 static int __init sh_rtc_init(void)
846 {
847 	return platform_driver_probe(&sh_rtc_platform_driver, sh_rtc_probe);
848 }
849 
850 static void __exit sh_rtc_exit(void)
851 {
852 	platform_driver_unregister(&sh_rtc_platform_driver);
853 }
854 
855 module_init(sh_rtc_init);
856 module_exit(sh_rtc_exit);
857 
858 MODULE_DESCRIPTION("SuperH on-chip RTC driver");
859 MODULE_VERSION(DRV_VERSION);
860 MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, "
861 	      "Jamie Lenehan <lenehan@twibble.org>, "
862 	      "Angelo Castello <angelo.castello@st.com>");
863 MODULE_LICENSE("GPL");
864 MODULE_ALIAS("platform:" DRV_NAME);
865