xref: /linux/drivers/rtc/rtc-sh.c (revision 02bf6cc72cc2a6258411ddf1649f33a65fc9a06e)
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 
289 	spin_unlock_irq(&rtc->lock);
290 	return ret;
291 }
292 
293 static inline void sh_rtc_setaie(struct device *dev, unsigned int enable)
294 {
295 	struct sh_rtc *rtc = dev_get_drvdata(dev);
296 	unsigned int tmp;
297 
298 	spin_lock_irq(&rtc->lock);
299 
300 	tmp = readb(rtc->regbase + RCR1);
301 
302 	if (enable)
303 		tmp |= RCR1_AIE;
304 	else
305 		tmp &= ~RCR1_AIE;
306 
307 	writeb(tmp, rtc->regbase + RCR1);
308 
309 	spin_unlock_irq(&rtc->lock);
310 }
311 
312 static int sh_rtc_proc(struct device *dev, struct seq_file *seq)
313 {
314 	struct sh_rtc *rtc = dev_get_drvdata(dev);
315 	unsigned int tmp;
316 
317 	tmp = readb(rtc->regbase + RCR1);
318 	seq_printf(seq, "carry_IRQ\t: %s\n", (tmp & RCR1_CIE) ? "yes" : "no");
319 
320 	tmp = readb(rtc->regbase + RCR2);
321 	seq_printf(seq, "periodic_IRQ\t: %s\n",
322 		   (tmp & RCR2_PESMASK) ? "yes" : "no");
323 
324 	return 0;
325 }
326 
327 static inline void sh_rtc_setcie(struct device *dev, unsigned int enable)
328 {
329 	struct sh_rtc *rtc = dev_get_drvdata(dev);
330 	unsigned int tmp;
331 
332 	spin_lock_irq(&rtc->lock);
333 
334 	tmp = readb(rtc->regbase + RCR1);
335 
336 	if (!enable)
337 		tmp &= ~RCR1_CIE;
338 	else
339 		tmp |= RCR1_CIE;
340 
341 	writeb(tmp, rtc->regbase + RCR1);
342 
343 	spin_unlock_irq(&rtc->lock);
344 }
345 
346 static int sh_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
347 {
348 	struct sh_rtc *rtc = dev_get_drvdata(dev);
349 	unsigned int ret = 0;
350 
351 	switch (cmd) {
352 	case RTC_AIE_OFF:
353 	case RTC_AIE_ON:
354 		sh_rtc_setaie(dev, cmd == RTC_AIE_ON);
355 		break;
356 	case RTC_UIE_OFF:
357 		rtc->periodic_freq &= ~PF_OXS;
358 		sh_rtc_setcie(dev, 0);
359 		break;
360 	case RTC_UIE_ON:
361 		rtc->periodic_freq |= PF_OXS;
362 		sh_rtc_setcie(dev, 1);
363 		break;
364 	default:
365 		ret = -ENOIOCTLCMD;
366 	}
367 
368 	return ret;
369 }
370 
371 static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm)
372 {
373 	struct platform_device *pdev = to_platform_device(dev);
374 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
375 	unsigned int sec128, sec2, yr, yr100, cf_bit;
376 
377 	do {
378 		unsigned int tmp;
379 
380 		spin_lock_irq(&rtc->lock);
381 
382 		tmp = readb(rtc->regbase + RCR1);
383 		tmp &= ~RCR1_CF; /* Clear CF-bit */
384 		tmp |= RCR1_CIE;
385 		writeb(tmp, rtc->regbase + RCR1);
386 
387 		sec128 = readb(rtc->regbase + R64CNT);
388 
389 		tm->tm_sec	= bcd2bin(readb(rtc->regbase + RSECCNT));
390 		tm->tm_min	= bcd2bin(readb(rtc->regbase + RMINCNT));
391 		tm->tm_hour	= bcd2bin(readb(rtc->regbase + RHRCNT));
392 		tm->tm_wday	= bcd2bin(readb(rtc->regbase + RWKCNT));
393 		tm->tm_mday	= bcd2bin(readb(rtc->regbase + RDAYCNT));
394 		tm->tm_mon	= bcd2bin(readb(rtc->regbase + RMONCNT)) - 1;
395 
396 		if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
397 			yr  = readw(rtc->regbase + RYRCNT);
398 			yr100 = bcd2bin(yr >> 8);
399 			yr &= 0xff;
400 		} else {
401 			yr  = readb(rtc->regbase + RYRCNT);
402 			yr100 = bcd2bin((yr == 0x99) ? 0x19 : 0x20);
403 		}
404 
405 		tm->tm_year = (yr100 * 100 + bcd2bin(yr)) - 1900;
406 
407 		sec2 = readb(rtc->regbase + R64CNT);
408 		cf_bit = readb(rtc->regbase + RCR1) & RCR1_CF;
409 
410 		spin_unlock_irq(&rtc->lock);
411 	} while (cf_bit != 0 || ((sec128 ^ sec2) & RTC_BIT_INVERTED) != 0);
412 
413 #if RTC_BIT_INVERTED != 0
414 	if ((sec128 & RTC_BIT_INVERTED))
415 		tm->tm_sec--;
416 #endif
417 
418 	/* only keep the carry interrupt enabled if UIE is on */
419 	if (!(rtc->periodic_freq & PF_OXS))
420 		sh_rtc_setcie(dev, 0);
421 
422 	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
423 		"mday=%d, mon=%d, year=%d, wday=%d\n",
424 		__func__,
425 		tm->tm_sec, tm->tm_min, tm->tm_hour,
426 		tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
427 
428 	return rtc_valid_tm(tm);
429 }
430 
431 static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm)
432 {
433 	struct platform_device *pdev = to_platform_device(dev);
434 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
435 	unsigned int tmp;
436 	int year;
437 
438 	spin_lock_irq(&rtc->lock);
439 
440 	/* Reset pre-scaler & stop RTC */
441 	tmp = readb(rtc->regbase + RCR2);
442 	tmp |= RCR2_RESET;
443 	tmp &= ~RCR2_START;
444 	writeb(tmp, rtc->regbase + RCR2);
445 
446 	writeb(bin2bcd(tm->tm_sec),  rtc->regbase + RSECCNT);
447 	writeb(bin2bcd(tm->tm_min),  rtc->regbase + RMINCNT);
448 	writeb(bin2bcd(tm->tm_hour), rtc->regbase + RHRCNT);
449 	writeb(bin2bcd(tm->tm_wday), rtc->regbase + RWKCNT);
450 	writeb(bin2bcd(tm->tm_mday), rtc->regbase + RDAYCNT);
451 	writeb(bin2bcd(tm->tm_mon + 1), rtc->regbase + RMONCNT);
452 
453 	if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
454 		year = (bin2bcd((tm->tm_year + 1900) / 100) << 8) |
455 			bin2bcd(tm->tm_year % 100);
456 		writew(year, rtc->regbase + RYRCNT);
457 	} else {
458 		year = tm->tm_year % 100;
459 		writeb(bin2bcd(year), rtc->regbase + RYRCNT);
460 	}
461 
462 	/* Start RTC */
463 	tmp = readb(rtc->regbase + RCR2);
464 	tmp &= ~RCR2_RESET;
465 	tmp |= RCR2_RTCEN | RCR2_START;
466 	writeb(tmp, rtc->regbase + RCR2);
467 
468 	spin_unlock_irq(&rtc->lock);
469 
470 	return 0;
471 }
472 
473 static inline int sh_rtc_read_alarm_value(struct sh_rtc *rtc, int reg_off)
474 {
475 	unsigned int byte;
476 	int value = 0xff;	/* return 0xff for ignored values */
477 
478 	byte = readb(rtc->regbase + reg_off);
479 	if (byte & AR_ENB) {
480 		byte &= ~AR_ENB;	/* strip the enable bit */
481 		value = bcd2bin(byte);
482 	}
483 
484 	return value;
485 }
486 
487 static int sh_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
488 {
489 	struct platform_device *pdev = to_platform_device(dev);
490 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
491 	struct rtc_time *tm = &wkalrm->time;
492 
493 	spin_lock_irq(&rtc->lock);
494 
495 	tm->tm_sec	= sh_rtc_read_alarm_value(rtc, RSECAR);
496 	tm->tm_min	= sh_rtc_read_alarm_value(rtc, RMINAR);
497 	tm->tm_hour	= sh_rtc_read_alarm_value(rtc, RHRAR);
498 	tm->tm_wday	= sh_rtc_read_alarm_value(rtc, RWKAR);
499 	tm->tm_mday	= sh_rtc_read_alarm_value(rtc, RDAYAR);
500 	tm->tm_mon	= sh_rtc_read_alarm_value(rtc, RMONAR);
501 	if (tm->tm_mon > 0)
502 		tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */
503 	tm->tm_year     = 0xffff;
504 
505 	wkalrm->enabled = (readb(rtc->regbase + RCR1) & RCR1_AIE) ? 1 : 0;
506 
507 	spin_unlock_irq(&rtc->lock);
508 
509 	return 0;
510 }
511 
512 static inline void sh_rtc_write_alarm_value(struct sh_rtc *rtc,
513 					    int value, int reg_off)
514 {
515 	/* < 0 for a value that is ignored */
516 	if (value < 0)
517 		writeb(0, rtc->regbase + reg_off);
518 	else
519 		writeb(bin2bcd(value) | AR_ENB,  rtc->regbase + reg_off);
520 }
521 
522 static int sh_rtc_check_alarm(struct rtc_time *tm)
523 {
524 	/*
525 	 * The original rtc says anything > 0xc0 is "don't care" or "match
526 	 * all" - most users use 0xff but rtc-dev uses -1 for the same thing.
527 	 * The original rtc doesn't support years - some things use -1 and
528 	 * some 0xffff. We use -1 to make out tests easier.
529 	 */
530 	if (tm->tm_year == 0xffff)
531 		tm->tm_year = -1;
532 	if (tm->tm_mon >= 0xff)
533 		tm->tm_mon = -1;
534 	if (tm->tm_mday >= 0xff)
535 		tm->tm_mday = -1;
536 	if (tm->tm_wday >= 0xff)
537 		tm->tm_wday = -1;
538 	if (tm->tm_hour >= 0xff)
539 		tm->tm_hour = -1;
540 	if (tm->tm_min >= 0xff)
541 		tm->tm_min = -1;
542 	if (tm->tm_sec >= 0xff)
543 		tm->tm_sec = -1;
544 
545 	if (tm->tm_year > 9999 ||
546 		tm->tm_mon >= 12 ||
547 		tm->tm_mday == 0 || tm->tm_mday >= 32 ||
548 		tm->tm_wday >= 7 ||
549 		tm->tm_hour >= 24 ||
550 		tm->tm_min >= 60 ||
551 		tm->tm_sec >= 60)
552 		return -EINVAL;
553 
554 	return 0;
555 }
556 
557 static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
558 {
559 	struct platform_device *pdev = to_platform_device(dev);
560 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
561 	unsigned int rcr1;
562 	struct rtc_time *tm = &wkalrm->time;
563 	int mon, err;
564 
565 	err = sh_rtc_check_alarm(tm);
566 	if (unlikely(err < 0))
567 		return err;
568 
569 	spin_lock_irq(&rtc->lock);
570 
571 	/* disable alarm interrupt and clear the alarm flag */
572 	rcr1 = readb(rtc->regbase + RCR1);
573 	rcr1 &= ~(RCR1_AF | RCR1_AIE);
574 	writeb(rcr1, rtc->regbase + RCR1);
575 
576 	/* set alarm time */
577 	sh_rtc_write_alarm_value(rtc, tm->tm_sec,  RSECAR);
578 	sh_rtc_write_alarm_value(rtc, tm->tm_min,  RMINAR);
579 	sh_rtc_write_alarm_value(rtc, tm->tm_hour, RHRAR);
580 	sh_rtc_write_alarm_value(rtc, tm->tm_wday, RWKAR);
581 	sh_rtc_write_alarm_value(rtc, tm->tm_mday, RDAYAR);
582 	mon = tm->tm_mon;
583 	if (mon >= 0)
584 		mon += 1;
585 	sh_rtc_write_alarm_value(rtc, mon, RMONAR);
586 
587 	if (wkalrm->enabled) {
588 		rcr1 |= RCR1_AIE;
589 		writeb(rcr1, rtc->regbase + RCR1);
590 	}
591 
592 	spin_unlock_irq(&rtc->lock);
593 
594 	return 0;
595 }
596 
597 static struct rtc_class_ops sh_rtc_ops = {
598 	.ioctl		= sh_rtc_ioctl,
599 	.read_time	= sh_rtc_read_time,
600 	.set_time	= sh_rtc_set_time,
601 	.read_alarm	= sh_rtc_read_alarm,
602 	.set_alarm	= sh_rtc_set_alarm,
603 	.irq_set_state	= sh_rtc_irq_set_state,
604 	.irq_set_freq	= sh_rtc_irq_set_freq,
605 	.proc		= sh_rtc_proc,
606 };
607 
608 static int __init sh_rtc_probe(struct platform_device *pdev)
609 {
610 	struct sh_rtc *rtc;
611 	struct resource *res;
612 	struct rtc_time r;
613 	char clk_name[6];
614 	int clk_id, ret;
615 
616 	rtc = kzalloc(sizeof(struct sh_rtc), GFP_KERNEL);
617 	if (unlikely(!rtc))
618 		return -ENOMEM;
619 
620 	spin_lock_init(&rtc->lock);
621 
622 	/* get periodic/carry/alarm irqs */
623 	ret = platform_get_irq(pdev, 0);
624 	if (unlikely(ret <= 0)) {
625 		ret = -ENOENT;
626 		dev_err(&pdev->dev, "No IRQ resource\n");
627 		goto err_badres;
628 	}
629 
630 	rtc->periodic_irq = ret;
631 	rtc->carry_irq = platform_get_irq(pdev, 1);
632 	rtc->alarm_irq = platform_get_irq(pdev, 2);
633 
634 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
635 	if (unlikely(res == NULL)) {
636 		ret = -ENOENT;
637 		dev_err(&pdev->dev, "No IO resource\n");
638 		goto err_badres;
639 	}
640 
641 	rtc->regsize = resource_size(res);
642 
643 	rtc->res = request_mem_region(res->start, rtc->regsize, pdev->name);
644 	if (unlikely(!rtc->res)) {
645 		ret = -EBUSY;
646 		goto err_badres;
647 	}
648 
649 	rtc->regbase = ioremap_nocache(rtc->res->start, rtc->regsize);
650 	if (unlikely(!rtc->regbase)) {
651 		ret = -EINVAL;
652 		goto err_badmap;
653 	}
654 
655 	clk_id = pdev->id;
656 	/* With a single device, the clock id is still "rtc0" */
657 	if (clk_id < 0)
658 		clk_id = 0;
659 
660 	snprintf(clk_name, sizeof(clk_name), "rtc%d", clk_id);
661 
662 	rtc->clk = clk_get(&pdev->dev, clk_name);
663 	if (IS_ERR(rtc->clk)) {
664 		/*
665 		 * No error handling for rtc->clk intentionally, not all
666 		 * platforms will have a unique clock for the RTC, and
667 		 * the clk API can handle the struct clk pointer being
668 		 * NULL.
669 		 */
670 		rtc->clk = NULL;
671 	}
672 
673 	clk_enable(rtc->clk);
674 
675 	rtc->capabilities = RTC_DEF_CAPABILITIES;
676 	if (pdev->dev.platform_data) {
677 		struct sh_rtc_platform_info *pinfo = pdev->dev.platform_data;
678 
679 		/*
680 		 * Some CPUs have special capabilities in addition to the
681 		 * default set. Add those in here.
682 		 */
683 		rtc->capabilities |= pinfo->capabilities;
684 	}
685 
686 	if (rtc->carry_irq <= 0) {
687 		/* register shared periodic/carry/alarm irq */
688 		ret = request_irq(rtc->periodic_irq, sh_rtc_shared,
689 				  IRQF_DISABLED, "sh-rtc", rtc);
690 		if (unlikely(ret)) {
691 			dev_err(&pdev->dev,
692 				"request IRQ failed with %d, IRQ %d\n", ret,
693 				rtc->periodic_irq);
694 			goto err_unmap;
695 		}
696 	} else {
697 		/* register periodic/carry/alarm irqs */
698 		ret = request_irq(rtc->periodic_irq, sh_rtc_periodic,
699 				  IRQF_DISABLED, "sh-rtc period", rtc);
700 		if (unlikely(ret)) {
701 			dev_err(&pdev->dev,
702 				"request period IRQ failed with %d, IRQ %d\n",
703 				ret, rtc->periodic_irq);
704 			goto err_unmap;
705 		}
706 
707 		ret = request_irq(rtc->carry_irq, sh_rtc_interrupt,
708 				  IRQF_DISABLED, "sh-rtc carry", rtc);
709 		if (unlikely(ret)) {
710 			dev_err(&pdev->dev,
711 				"request carry IRQ failed with %d, IRQ %d\n",
712 				ret, rtc->carry_irq);
713 			free_irq(rtc->periodic_irq, rtc);
714 			goto err_unmap;
715 		}
716 
717 		ret = request_irq(rtc->alarm_irq, sh_rtc_alarm,
718 				  IRQF_DISABLED, "sh-rtc alarm", rtc);
719 		if (unlikely(ret)) {
720 			dev_err(&pdev->dev,
721 				"request alarm IRQ failed with %d, IRQ %d\n",
722 				ret, rtc->alarm_irq);
723 			free_irq(rtc->carry_irq, rtc);
724 			free_irq(rtc->periodic_irq, rtc);
725 			goto err_unmap;
726 		}
727 	}
728 
729 	platform_set_drvdata(pdev, rtc);
730 
731 	/* everything disabled by default */
732 	sh_rtc_irq_set_freq(&pdev->dev, 0);
733 	sh_rtc_irq_set_state(&pdev->dev, 0);
734 	sh_rtc_setaie(&pdev->dev, 0);
735 	sh_rtc_setcie(&pdev->dev, 0);
736 
737 	rtc->rtc_dev = rtc_device_register("sh", &pdev->dev,
738 					   &sh_rtc_ops, THIS_MODULE);
739 	if (IS_ERR(rtc->rtc_dev)) {
740 		ret = PTR_ERR(rtc->rtc_dev);
741 		free_irq(rtc->periodic_irq, rtc);
742 		free_irq(rtc->carry_irq, rtc);
743 		free_irq(rtc->alarm_irq, rtc);
744 		goto err_unmap;
745 	}
746 
747 	rtc->rtc_dev->max_user_freq = 256;
748 
749 	/* reset rtc to epoch 0 if time is invalid */
750 	if (rtc_read_time(rtc->rtc_dev, &r) < 0) {
751 		rtc_time_to_tm(0, &r);
752 		rtc_set_time(rtc->rtc_dev, &r);
753 	}
754 
755 	device_init_wakeup(&pdev->dev, 1);
756 	return 0;
757 
758 err_unmap:
759 	clk_disable(rtc->clk);
760 	clk_put(rtc->clk);
761 	iounmap(rtc->regbase);
762 err_badmap:
763 	release_resource(rtc->res);
764 err_badres:
765 	kfree(rtc);
766 
767 	return ret;
768 }
769 
770 static int __exit sh_rtc_remove(struct platform_device *pdev)
771 {
772 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
773 
774 	rtc_device_unregister(rtc->rtc_dev);
775 	sh_rtc_irq_set_state(&pdev->dev, 0);
776 
777 	sh_rtc_setaie(&pdev->dev, 0);
778 	sh_rtc_setcie(&pdev->dev, 0);
779 
780 	free_irq(rtc->periodic_irq, rtc);
781 
782 	if (rtc->carry_irq > 0) {
783 		free_irq(rtc->carry_irq, rtc);
784 		free_irq(rtc->alarm_irq, rtc);
785 	}
786 
787 	iounmap(rtc->regbase);
788 	release_resource(rtc->res);
789 
790 	clk_disable(rtc->clk);
791 	clk_put(rtc->clk);
792 
793 	platform_set_drvdata(pdev, NULL);
794 
795 	kfree(rtc);
796 
797 	return 0;
798 }
799 
800 static void sh_rtc_set_irq_wake(struct device *dev, int enabled)
801 {
802 	struct platform_device *pdev = to_platform_device(dev);
803 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
804 
805 	set_irq_wake(rtc->periodic_irq, enabled);
806 
807 	if (rtc->carry_irq > 0) {
808 		set_irq_wake(rtc->carry_irq, enabled);
809 		set_irq_wake(rtc->alarm_irq, enabled);
810 	}
811 }
812 
813 static int sh_rtc_suspend(struct device *dev)
814 {
815 	if (device_may_wakeup(dev))
816 		sh_rtc_set_irq_wake(dev, 1);
817 
818 	return 0;
819 }
820 
821 static int sh_rtc_resume(struct device *dev)
822 {
823 	if (device_may_wakeup(dev))
824 		sh_rtc_set_irq_wake(dev, 0);
825 
826 	return 0;
827 }
828 
829 static const struct dev_pm_ops sh_rtc_dev_pm_ops = {
830 	.suspend = sh_rtc_suspend,
831 	.resume = sh_rtc_resume,
832 };
833 
834 static struct platform_driver sh_rtc_platform_driver = {
835 	.driver		= {
836 		.name	= DRV_NAME,
837 		.owner	= THIS_MODULE,
838 		.pm	= &sh_rtc_dev_pm_ops,
839 	},
840 	.remove		= __exit_p(sh_rtc_remove),
841 };
842 
843 static int __init sh_rtc_init(void)
844 {
845 	return platform_driver_probe(&sh_rtc_platform_driver, sh_rtc_probe);
846 }
847 
848 static void __exit sh_rtc_exit(void)
849 {
850 	platform_driver_unregister(&sh_rtc_platform_driver);
851 }
852 
853 module_init(sh_rtc_init);
854 module_exit(sh_rtc_exit);
855 
856 MODULE_DESCRIPTION("SuperH on-chip RTC driver");
857 MODULE_VERSION(DRV_VERSION);
858 MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, "
859 	      "Jamie Lenehan <lenehan@twibble.org>, "
860 	      "Angelo Castello <angelo.castello@st.com>");
861 MODULE_LICENSE("GPL");
862 MODULE_ALIAS("platform:" DRV_NAME);
863