xref: /openbmc/linux/drivers/rtc/rtc-sh.c (revision 78c99ba1)
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	"0.2.2"
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 inline void sh_rtc_setpie(struct device *dev, unsigned 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 		tmp &= ~RCR2_PEF;	/* Clear PES bit */
229 		tmp |= (rtc->periodic_freq & ~PF_HP);	/* Set PES2-0 */
230 	} else
231 		tmp &= ~(RCR2_PESMASK | RCR2_PEF);
232 
233 	writeb(tmp, rtc->regbase + RCR2);
234 
235 	spin_unlock_irq(&rtc->lock);
236 }
237 
238 static inline int sh_rtc_setfreq(struct device *dev, unsigned int freq)
239 {
240 	struct sh_rtc *rtc = dev_get_drvdata(dev);
241 	int tmp, ret = 0;
242 
243 	spin_lock_irq(&rtc->lock);
244 	tmp = rtc->periodic_freq & PF_MASK;
245 
246 	switch (freq) {
247 	case 0:
248 		rtc->periodic_freq = 0x00;
249 		break;
250 	case 1:
251 		rtc->periodic_freq = 0x60;
252 		break;
253 	case 2:
254 		rtc->periodic_freq = 0x50;
255 		break;
256 	case 4:
257 		rtc->periodic_freq = 0x40;
258 		break;
259 	case 8:
260 		rtc->periodic_freq = 0x30 | PF_HP;
261 		break;
262 	case 16:
263 		rtc->periodic_freq = 0x30;
264 		break;
265 	case 32:
266 		rtc->periodic_freq = 0x20 | PF_HP;
267 		break;
268 	case 64:
269 		rtc->periodic_freq = 0x20;
270 		break;
271 	case 128:
272 		rtc->periodic_freq = 0x10 | PF_HP;
273 		break;
274 	case 256:
275 		rtc->periodic_freq = 0x10;
276 		break;
277 	default:
278 		ret = -ENOTSUPP;
279 	}
280 
281 	if (ret == 0) {
282 		rtc->periodic_freq |= tmp;
283 		rtc->rtc_dev->irq_freq = freq;
284 	}
285 
286 	spin_unlock_irq(&rtc->lock);
287 	return ret;
288 }
289 
290 static inline void sh_rtc_setaie(struct device *dev, unsigned int enable)
291 {
292 	struct sh_rtc *rtc = dev_get_drvdata(dev);
293 	unsigned int tmp;
294 
295 	spin_lock_irq(&rtc->lock);
296 
297 	tmp = readb(rtc->regbase + RCR1);
298 
299 	if (enable)
300 		tmp |= RCR1_AIE;
301 	else
302 		tmp &= ~RCR1_AIE;
303 
304 	writeb(tmp, rtc->regbase + RCR1);
305 
306 	spin_unlock_irq(&rtc->lock);
307 }
308 
309 static int sh_rtc_proc(struct device *dev, struct seq_file *seq)
310 {
311 	struct sh_rtc *rtc = dev_get_drvdata(dev);
312 	unsigned int tmp;
313 
314 	tmp = readb(rtc->regbase + RCR1);
315 	seq_printf(seq, "carry_IRQ\t: %s\n", (tmp & RCR1_CIE) ? "yes" : "no");
316 
317 	tmp = readb(rtc->regbase + RCR2);
318 	seq_printf(seq, "periodic_IRQ\t: %s\n",
319 		   (tmp & RCR2_PESMASK) ? "yes" : "no");
320 
321 	return 0;
322 }
323 
324 static inline void sh_rtc_setcie(struct device *dev, unsigned int enable)
325 {
326 	struct sh_rtc *rtc = dev_get_drvdata(dev);
327 	unsigned int tmp;
328 
329 	spin_lock_irq(&rtc->lock);
330 
331 	tmp = readb(rtc->regbase + RCR1);
332 
333 	if (!enable)
334 		tmp &= ~RCR1_CIE;
335 	else
336 		tmp |= RCR1_CIE;
337 
338 	writeb(tmp, rtc->regbase + RCR1);
339 
340 	spin_unlock_irq(&rtc->lock);
341 }
342 
343 static int sh_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
344 {
345 	struct sh_rtc *rtc = dev_get_drvdata(dev);
346 	unsigned int ret = 0;
347 
348 	switch (cmd) {
349 	case RTC_PIE_OFF:
350 	case RTC_PIE_ON:
351 		sh_rtc_setpie(dev, cmd == RTC_PIE_ON);
352 		break;
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 	case RTC_IRQP_READ:
366 		ret = put_user(rtc->rtc_dev->irq_freq,
367 			       (unsigned long __user *)arg);
368 		break;
369 	case RTC_IRQP_SET:
370 		ret = sh_rtc_setfreq(dev, arg);
371 		break;
372 	default:
373 		ret = -ENOIOCTLCMD;
374 	}
375 
376 	return ret;
377 }
378 
379 static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm)
380 {
381 	struct platform_device *pdev = to_platform_device(dev);
382 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
383 	unsigned int sec128, sec2, yr, yr100, cf_bit;
384 
385 	do {
386 		unsigned int tmp;
387 
388 		spin_lock_irq(&rtc->lock);
389 
390 		tmp = readb(rtc->regbase + RCR1);
391 		tmp &= ~RCR1_CF; /* Clear CF-bit */
392 		tmp |= RCR1_CIE;
393 		writeb(tmp, rtc->regbase + RCR1);
394 
395 		sec128 = readb(rtc->regbase + R64CNT);
396 
397 		tm->tm_sec	= bcd2bin(readb(rtc->regbase + RSECCNT));
398 		tm->tm_min	= bcd2bin(readb(rtc->regbase + RMINCNT));
399 		tm->tm_hour	= bcd2bin(readb(rtc->regbase + RHRCNT));
400 		tm->tm_wday	= bcd2bin(readb(rtc->regbase + RWKCNT));
401 		tm->tm_mday	= bcd2bin(readb(rtc->regbase + RDAYCNT));
402 		tm->tm_mon	= bcd2bin(readb(rtc->regbase + RMONCNT)) - 1;
403 
404 		if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
405 			yr  = readw(rtc->regbase + RYRCNT);
406 			yr100 = bcd2bin(yr >> 8);
407 			yr &= 0xff;
408 		} else {
409 			yr  = readb(rtc->regbase + RYRCNT);
410 			yr100 = bcd2bin((yr == 0x99) ? 0x19 : 0x20);
411 		}
412 
413 		tm->tm_year = (yr100 * 100 + bcd2bin(yr)) - 1900;
414 
415 		sec2 = readb(rtc->regbase + R64CNT);
416 		cf_bit = readb(rtc->regbase + RCR1) & RCR1_CF;
417 
418 		spin_unlock_irq(&rtc->lock);
419 	} while (cf_bit != 0 || ((sec128 ^ sec2) & RTC_BIT_INVERTED) != 0);
420 
421 #if RTC_BIT_INVERTED != 0
422 	if ((sec128 & RTC_BIT_INVERTED))
423 		tm->tm_sec--;
424 #endif
425 
426 	/* only keep the carry interrupt enabled if UIE is on */
427 	if (!(rtc->periodic_freq & PF_OXS))
428 		sh_rtc_setcie(dev, 0);
429 
430 	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
431 		"mday=%d, mon=%d, year=%d, wday=%d\n",
432 		__func__,
433 		tm->tm_sec, tm->tm_min, tm->tm_hour,
434 		tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
435 
436 	return rtc_valid_tm(tm);
437 }
438 
439 static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm)
440 {
441 	struct platform_device *pdev = to_platform_device(dev);
442 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
443 	unsigned int tmp;
444 	int year;
445 
446 	spin_lock_irq(&rtc->lock);
447 
448 	/* Reset pre-scaler & stop RTC */
449 	tmp = readb(rtc->regbase + RCR2);
450 	tmp |= RCR2_RESET;
451 	tmp &= ~RCR2_START;
452 	writeb(tmp, rtc->regbase + RCR2);
453 
454 	writeb(bin2bcd(tm->tm_sec),  rtc->regbase + RSECCNT);
455 	writeb(bin2bcd(tm->tm_min),  rtc->regbase + RMINCNT);
456 	writeb(bin2bcd(tm->tm_hour), rtc->regbase + RHRCNT);
457 	writeb(bin2bcd(tm->tm_wday), rtc->regbase + RWKCNT);
458 	writeb(bin2bcd(tm->tm_mday), rtc->regbase + RDAYCNT);
459 	writeb(bin2bcd(tm->tm_mon + 1), rtc->regbase + RMONCNT);
460 
461 	if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
462 		year = (bin2bcd((tm->tm_year + 1900) / 100) << 8) |
463 			bin2bcd(tm->tm_year % 100);
464 		writew(year, rtc->regbase + RYRCNT);
465 	} else {
466 		year = tm->tm_year % 100;
467 		writeb(bin2bcd(year), rtc->regbase + RYRCNT);
468 	}
469 
470 	/* Start RTC */
471 	tmp = readb(rtc->regbase + RCR2);
472 	tmp &= ~RCR2_RESET;
473 	tmp |= RCR2_RTCEN | RCR2_START;
474 	writeb(tmp, rtc->regbase + RCR2);
475 
476 	spin_unlock_irq(&rtc->lock);
477 
478 	return 0;
479 }
480 
481 static inline int sh_rtc_read_alarm_value(struct sh_rtc *rtc, int reg_off)
482 {
483 	unsigned int byte;
484 	int value = 0xff;	/* return 0xff for ignored values */
485 
486 	byte = readb(rtc->regbase + reg_off);
487 	if (byte & AR_ENB) {
488 		byte &= ~AR_ENB;	/* strip the enable bit */
489 		value = bcd2bin(byte);
490 	}
491 
492 	return value;
493 }
494 
495 static int sh_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
496 {
497 	struct platform_device *pdev = to_platform_device(dev);
498 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
499 	struct rtc_time *tm = &wkalrm->time;
500 
501 	spin_lock_irq(&rtc->lock);
502 
503 	tm->tm_sec	= sh_rtc_read_alarm_value(rtc, RSECAR);
504 	tm->tm_min	= sh_rtc_read_alarm_value(rtc, RMINAR);
505 	tm->tm_hour	= sh_rtc_read_alarm_value(rtc, RHRAR);
506 	tm->tm_wday	= sh_rtc_read_alarm_value(rtc, RWKAR);
507 	tm->tm_mday	= sh_rtc_read_alarm_value(rtc, RDAYAR);
508 	tm->tm_mon	= sh_rtc_read_alarm_value(rtc, RMONAR);
509 	if (tm->tm_mon > 0)
510 		tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */
511 	tm->tm_year     = 0xffff;
512 
513 	wkalrm->enabled = (readb(rtc->regbase + RCR1) & RCR1_AIE) ? 1 : 0;
514 
515 	spin_unlock_irq(&rtc->lock);
516 
517 	return 0;
518 }
519 
520 static inline void sh_rtc_write_alarm_value(struct sh_rtc *rtc,
521 					    int value, int reg_off)
522 {
523 	/* < 0 for a value that is ignored */
524 	if (value < 0)
525 		writeb(0, rtc->regbase + reg_off);
526 	else
527 		writeb(bin2bcd(value) | AR_ENB,  rtc->regbase + reg_off);
528 }
529 
530 static int sh_rtc_check_alarm(struct rtc_time *tm)
531 {
532 	/*
533 	 * The original rtc says anything > 0xc0 is "don't care" or "match
534 	 * all" - most users use 0xff but rtc-dev uses -1 for the same thing.
535 	 * The original rtc doesn't support years - some things use -1 and
536 	 * some 0xffff. We use -1 to make out tests easier.
537 	 */
538 	if (tm->tm_year == 0xffff)
539 		tm->tm_year = -1;
540 	if (tm->tm_mon >= 0xff)
541 		tm->tm_mon = -1;
542 	if (tm->tm_mday >= 0xff)
543 		tm->tm_mday = -1;
544 	if (tm->tm_wday >= 0xff)
545 		tm->tm_wday = -1;
546 	if (tm->tm_hour >= 0xff)
547 		tm->tm_hour = -1;
548 	if (tm->tm_min >= 0xff)
549 		tm->tm_min = -1;
550 	if (tm->tm_sec >= 0xff)
551 		tm->tm_sec = -1;
552 
553 	if (tm->tm_year > 9999 ||
554 		tm->tm_mon >= 12 ||
555 		tm->tm_mday == 0 || tm->tm_mday >= 32 ||
556 		tm->tm_wday >= 7 ||
557 		tm->tm_hour >= 24 ||
558 		tm->tm_min >= 60 ||
559 		tm->tm_sec >= 60)
560 		return -EINVAL;
561 
562 	return 0;
563 }
564 
565 static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
566 {
567 	struct platform_device *pdev = to_platform_device(dev);
568 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
569 	unsigned int rcr1;
570 	struct rtc_time *tm = &wkalrm->time;
571 	int mon, err;
572 
573 	err = sh_rtc_check_alarm(tm);
574 	if (unlikely(err < 0))
575 		return err;
576 
577 	spin_lock_irq(&rtc->lock);
578 
579 	/* disable alarm interrupt and clear the alarm flag */
580 	rcr1 = readb(rtc->regbase + RCR1);
581 	rcr1 &= ~(RCR1_AF | RCR1_AIE);
582 	writeb(rcr1, rtc->regbase + RCR1);
583 
584 	/* set alarm time */
585 	sh_rtc_write_alarm_value(rtc, tm->tm_sec,  RSECAR);
586 	sh_rtc_write_alarm_value(rtc, tm->tm_min,  RMINAR);
587 	sh_rtc_write_alarm_value(rtc, tm->tm_hour, RHRAR);
588 	sh_rtc_write_alarm_value(rtc, tm->tm_wday, RWKAR);
589 	sh_rtc_write_alarm_value(rtc, tm->tm_mday, RDAYAR);
590 	mon = tm->tm_mon;
591 	if (mon >= 0)
592 		mon += 1;
593 	sh_rtc_write_alarm_value(rtc, mon, RMONAR);
594 
595 	if (wkalrm->enabled) {
596 		rcr1 |= RCR1_AIE;
597 		writeb(rcr1, rtc->regbase + RCR1);
598 	}
599 
600 	spin_unlock_irq(&rtc->lock);
601 
602 	return 0;
603 }
604 
605 static int sh_rtc_irq_set_state(struct device *dev, int enabled)
606 {
607 	struct platform_device *pdev = to_platform_device(dev);
608 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
609 
610 	if (enabled) {
611 		rtc->periodic_freq |= PF_KOU;
612 		return sh_rtc_ioctl(dev, RTC_PIE_ON, 0);
613 	} else {
614 		rtc->periodic_freq &= ~PF_KOU;
615 		return sh_rtc_ioctl(dev, RTC_PIE_OFF, 0);
616 	}
617 }
618 
619 static int sh_rtc_irq_set_freq(struct device *dev, int freq)
620 {
621 	if (!is_power_of_2(freq))
622 		return -EINVAL;
623 
624 	return sh_rtc_ioctl(dev, RTC_IRQP_SET, freq);
625 }
626 
627 static struct rtc_class_ops sh_rtc_ops = {
628 	.ioctl		= sh_rtc_ioctl,
629 	.read_time	= sh_rtc_read_time,
630 	.set_time	= sh_rtc_set_time,
631 	.read_alarm	= sh_rtc_read_alarm,
632 	.set_alarm	= sh_rtc_set_alarm,
633 	.irq_set_state	= sh_rtc_irq_set_state,
634 	.irq_set_freq	= sh_rtc_irq_set_freq,
635 	.proc		= sh_rtc_proc,
636 };
637 
638 static int __devinit sh_rtc_probe(struct platform_device *pdev)
639 {
640 	struct sh_rtc *rtc;
641 	struct resource *res;
642 	struct rtc_time r;
643 	char clk_name[6];
644 	int clk_id, ret;
645 
646 	rtc = kzalloc(sizeof(struct sh_rtc), GFP_KERNEL);
647 	if (unlikely(!rtc))
648 		return -ENOMEM;
649 
650 	spin_lock_init(&rtc->lock);
651 
652 	/* get periodic/carry/alarm irqs */
653 	ret = platform_get_irq(pdev, 0);
654 	if (unlikely(ret <= 0)) {
655 		ret = -ENOENT;
656 		dev_err(&pdev->dev, "No IRQ resource\n");
657 		goto err_badres;
658 	}
659 
660 	rtc->periodic_irq = ret;
661 	rtc->carry_irq = platform_get_irq(pdev, 1);
662 	rtc->alarm_irq = platform_get_irq(pdev, 2);
663 
664 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
665 	if (unlikely(res == NULL)) {
666 		ret = -ENOENT;
667 		dev_err(&pdev->dev, "No IO resource\n");
668 		goto err_badres;
669 	}
670 
671 	rtc->regsize = resource_size(res);
672 
673 	rtc->res = request_mem_region(res->start, rtc->regsize, pdev->name);
674 	if (unlikely(!rtc->res)) {
675 		ret = -EBUSY;
676 		goto err_badres;
677 	}
678 
679 	rtc->regbase = ioremap_nocache(rtc->res->start, rtc->regsize);
680 	if (unlikely(!rtc->regbase)) {
681 		ret = -EINVAL;
682 		goto err_badmap;
683 	}
684 
685 	clk_id = pdev->id;
686 	/* With a single device, the clock id is still "rtc0" */
687 	if (clk_id < 0)
688 		clk_id = 0;
689 
690 	snprintf(clk_name, sizeof(clk_name), "rtc%d", clk_id);
691 
692 	rtc->clk = clk_get(&pdev->dev, clk_name);
693 	if (IS_ERR(rtc->clk)) {
694 		/*
695 		 * No error handling for rtc->clk intentionally, not all
696 		 * platforms will have a unique clock for the RTC, and
697 		 * the clk API can handle the struct clk pointer being
698 		 * NULL.
699 		 */
700 		rtc->clk = NULL;
701 	}
702 
703 	clk_enable(rtc->clk);
704 
705 	rtc->rtc_dev = rtc_device_register("sh", &pdev->dev,
706 					   &sh_rtc_ops, THIS_MODULE);
707 	if (IS_ERR(rtc->rtc_dev)) {
708 		ret = PTR_ERR(rtc->rtc_dev);
709 		goto err_unmap;
710 	}
711 
712 	rtc->capabilities = RTC_DEF_CAPABILITIES;
713 	if (pdev->dev.platform_data) {
714 		struct sh_rtc_platform_info *pinfo = pdev->dev.platform_data;
715 
716 		/*
717 		 * Some CPUs have special capabilities in addition to the
718 		 * default set. Add those in here.
719 		 */
720 		rtc->capabilities |= pinfo->capabilities;
721 	}
722 
723 	rtc->rtc_dev->max_user_freq = 256;
724 
725 	platform_set_drvdata(pdev, rtc);
726 
727 	if (rtc->carry_irq <= 0) {
728 		/* register shared periodic/carry/alarm irq */
729 		ret = request_irq(rtc->periodic_irq, sh_rtc_shared,
730 				  IRQF_DISABLED, "sh-rtc", rtc);
731 		if (unlikely(ret)) {
732 			dev_err(&pdev->dev,
733 				"request IRQ failed with %d, IRQ %d\n", ret,
734 				rtc->periodic_irq);
735 			goto err_unmap;
736 		}
737 	} else {
738 		/* register periodic/carry/alarm irqs */
739 		ret = request_irq(rtc->periodic_irq, sh_rtc_periodic,
740 				  IRQF_DISABLED, "sh-rtc period", rtc);
741 		if (unlikely(ret)) {
742 			dev_err(&pdev->dev,
743 				"request period IRQ failed with %d, IRQ %d\n",
744 				ret, rtc->periodic_irq);
745 			goto err_unmap;
746 		}
747 
748 		ret = request_irq(rtc->carry_irq, sh_rtc_interrupt,
749 				  IRQF_DISABLED, "sh-rtc carry", rtc);
750 		if (unlikely(ret)) {
751 			dev_err(&pdev->dev,
752 				"request carry IRQ failed with %d, IRQ %d\n",
753 				ret, rtc->carry_irq);
754 			free_irq(rtc->periodic_irq, rtc);
755 			goto err_unmap;
756 		}
757 
758 		ret = request_irq(rtc->alarm_irq, sh_rtc_alarm,
759 				  IRQF_DISABLED, "sh-rtc alarm", rtc);
760 		if (unlikely(ret)) {
761 			dev_err(&pdev->dev,
762 				"request alarm IRQ failed with %d, IRQ %d\n",
763 				ret, rtc->alarm_irq);
764 			free_irq(rtc->carry_irq, rtc);
765 			free_irq(rtc->periodic_irq, rtc);
766 			goto err_unmap;
767 		}
768 	}
769 
770 	/* everything disabled by default */
771 	rtc->periodic_freq = 0;
772 	rtc->rtc_dev->irq_freq = 0;
773 	sh_rtc_setpie(&pdev->dev, 0);
774 	sh_rtc_setaie(&pdev->dev, 0);
775 	sh_rtc_setcie(&pdev->dev, 0);
776 
777 	/* reset rtc to epoch 0 if time is invalid */
778 	if (rtc_read_time(rtc->rtc_dev, &r) < 0) {
779 		rtc_time_to_tm(0, &r);
780 		rtc_set_time(rtc->rtc_dev, &r);
781 	}
782 
783 	device_init_wakeup(&pdev->dev, 1);
784 	return 0;
785 
786 err_unmap:
787 	clk_disable(rtc->clk);
788 	clk_put(rtc->clk);
789 	iounmap(rtc->regbase);
790 err_badmap:
791 	release_resource(rtc->res);
792 err_badres:
793 	kfree(rtc);
794 
795 	return ret;
796 }
797 
798 static int __devexit sh_rtc_remove(struct platform_device *pdev)
799 {
800 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
801 
802 	if (likely(rtc->rtc_dev))
803 		rtc_device_unregister(rtc->rtc_dev);
804 
805 	sh_rtc_setpie(&pdev->dev, 0);
806 	sh_rtc_setaie(&pdev->dev, 0);
807 	sh_rtc_setcie(&pdev->dev, 0);
808 
809 	free_irq(rtc->periodic_irq, rtc);
810 
811 	if (rtc->carry_irq > 0) {
812 		free_irq(rtc->carry_irq, rtc);
813 		free_irq(rtc->alarm_irq, rtc);
814 	}
815 
816 	release_resource(rtc->res);
817 
818 	iounmap(rtc->regbase);
819 
820 	clk_disable(rtc->clk);
821 	clk_put(rtc->clk);
822 
823 	platform_set_drvdata(pdev, NULL);
824 
825 	kfree(rtc);
826 
827 	return 0;
828 }
829 
830 static void sh_rtc_set_irq_wake(struct device *dev, int enabled)
831 {
832 	struct platform_device *pdev = to_platform_device(dev);
833 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
834 
835 	set_irq_wake(rtc->periodic_irq, enabled);
836 
837 	if (rtc->carry_irq > 0) {
838 		set_irq_wake(rtc->carry_irq, enabled);
839 		set_irq_wake(rtc->alarm_irq, enabled);
840 	}
841 }
842 
843 static int sh_rtc_suspend(struct device *dev)
844 {
845 	if (device_may_wakeup(dev))
846 		sh_rtc_set_irq_wake(dev, 1);
847 
848 	return 0;
849 }
850 
851 static int sh_rtc_resume(struct device *dev)
852 {
853 	if (device_may_wakeup(dev))
854 		sh_rtc_set_irq_wake(dev, 0);
855 
856 	return 0;
857 }
858 
859 static struct dev_pm_ops sh_rtc_dev_pm_ops = {
860 	.suspend = sh_rtc_suspend,
861 	.resume = sh_rtc_resume,
862 };
863 
864 static struct platform_driver sh_rtc_platform_driver = {
865 	.driver		= {
866 		.name	= DRV_NAME,
867 		.owner	= THIS_MODULE,
868 		.pm	= &sh_rtc_dev_pm_ops,
869 	},
870 	.probe		= sh_rtc_probe,
871 	.remove		= __devexit_p(sh_rtc_remove),
872 };
873 
874 static int __init sh_rtc_init(void)
875 {
876 	return platform_driver_register(&sh_rtc_platform_driver);
877 }
878 
879 static void __exit sh_rtc_exit(void)
880 {
881 	platform_driver_unregister(&sh_rtc_platform_driver);
882 }
883 
884 module_init(sh_rtc_init);
885 module_exit(sh_rtc_exit);
886 
887 MODULE_DESCRIPTION("SuperH on-chip RTC driver");
888 MODULE_VERSION(DRV_VERSION);
889 MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, "
890 	      "Jamie Lenehan <lenehan@twibble.org>, "
891 	      "Angelo Castello <angelo.castello@st.com>");
892 MODULE_LICENSE("GPL");
893 MODULE_ALIAS("platform:" DRV_NAME);
894