xref: /openbmc/linux/drivers/rtc/rtc-sh.c (revision 643d1f7f)
1 /*
2  * SuperH On-Chip RTC Support
3  *
4  * Copyright (C) 2006, 2007  Paul Mundt
5  * Copyright (C) 2006  Jamie Lenehan
6  *
7  * Based on the old arch/sh/kernel/cpu/rtc.c by:
8  *
9  *  Copyright (C) 2000  Philipp Rumpf <prumpf@tux.org>
10  *  Copyright (C) 1999  Tetsuya Okada & Niibe Yutaka
11  *
12  * This file is subject to the terms and conditions of the GNU General Public
13  * License.  See the file "COPYING" in the main directory of this archive
14  * for more details.
15  */
16 #include <linux/module.h>
17 #include <linux/kernel.h>
18 #include <linux/bcd.h>
19 #include <linux/rtc.h>
20 #include <linux/init.h>
21 #include <linux/platform_device.h>
22 #include <linux/seq_file.h>
23 #include <linux/interrupt.h>
24 #include <linux/spinlock.h>
25 #include <linux/io.h>
26 #include <asm/rtc.h>
27 
28 #define DRV_NAME	"sh-rtc"
29 #define DRV_VERSION	"0.1.6"
30 
31 #define RTC_REG(r)	((r) * rtc_reg_size)
32 
33 #define R64CNT		RTC_REG(0)
34 
35 #define RSECCNT		RTC_REG(1)	/* RTC sec */
36 #define RMINCNT		RTC_REG(2)	/* RTC min */
37 #define RHRCNT		RTC_REG(3)	/* RTC hour */
38 #define RWKCNT		RTC_REG(4)	/* RTC week */
39 #define RDAYCNT		RTC_REG(5)	/* RTC day */
40 #define RMONCNT		RTC_REG(6)	/* RTC month */
41 #define RYRCNT		RTC_REG(7)	/* RTC year */
42 #define RSECAR		RTC_REG(8)	/* ALARM sec */
43 #define RMINAR		RTC_REG(9)	/* ALARM min */
44 #define RHRAR		RTC_REG(10)	/* ALARM hour */
45 #define RWKAR		RTC_REG(11)	/* ALARM week */
46 #define RDAYAR		RTC_REG(12)	/* ALARM day */
47 #define RMONAR		RTC_REG(13)	/* ALARM month */
48 #define RCR1		RTC_REG(14)	/* Control */
49 #define RCR2		RTC_REG(15)	/* Control */
50 
51 /*
52  * Note on RYRAR and RCR3: Up until this point most of the register
53  * definitions are consistent across all of the available parts. However,
54  * the placement of the optional RYRAR and RCR3 (the RYRAR control
55  * register used to control RYRCNT/RYRAR compare) varies considerably
56  * across various parts, occasionally being mapped in to a completely
57  * unrelated address space. For proper RYRAR support a separate resource
58  * would have to be handed off, but as this is purely optional in
59  * practice, we simply opt not to support it, thereby keeping the code
60  * quite a bit more simplified.
61  */
62 
63 /* ALARM Bits - or with BCD encoded value */
64 #define AR_ENB		0x80	/* Enable for alarm cmp   */
65 
66 /* RCR1 Bits */
67 #define RCR1_CF		0x80	/* Carry Flag             */
68 #define RCR1_CIE	0x10	/* Carry Interrupt Enable */
69 #define RCR1_AIE	0x08	/* Alarm Interrupt Enable */
70 #define RCR1_AF		0x01	/* Alarm Flag             */
71 
72 /* RCR2 Bits */
73 #define RCR2_PEF	0x80	/* PEriodic interrupt Flag */
74 #define RCR2_PESMASK	0x70	/* Periodic interrupt Set  */
75 #define RCR2_RTCEN	0x08	/* ENable RTC              */
76 #define RCR2_ADJ	0x04	/* ADJustment (30-second)  */
77 #define RCR2_RESET	0x02	/* Reset bit               */
78 #define RCR2_START	0x01	/* Start bit               */
79 
80 struct sh_rtc {
81 	void __iomem *regbase;
82 	unsigned long regsize;
83 	struct resource *res;
84 	unsigned int alarm_irq, periodic_irq, carry_irq;
85 	struct rtc_device *rtc_dev;
86 	spinlock_t lock;
87 	int rearm_aie;
88 	unsigned long capabilities;	/* See asm-sh/rtc.h for cap bits */
89 };
90 
91 static irqreturn_t sh_rtc_interrupt(int irq, void *dev_id)
92 {
93 	struct platform_device *pdev = to_platform_device(dev_id);
94 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
95 	unsigned int tmp, events = 0;
96 
97 	spin_lock(&rtc->lock);
98 
99 	tmp = readb(rtc->regbase + RCR1);
100 	tmp &= ~RCR1_CF;
101 
102 	if (rtc->rearm_aie) {
103 		if (tmp & RCR1_AF)
104 			tmp &= ~RCR1_AF;	/* try to clear AF again */
105 		else {
106 			tmp |= RCR1_AIE;	/* AF has cleared, rearm IRQ */
107 			rtc->rearm_aie = 0;
108 		}
109 	}
110 
111 	writeb(tmp, rtc->regbase + RCR1);
112 
113 	rtc_update_irq(rtc->rtc_dev, 1, events);
114 
115 	spin_unlock(&rtc->lock);
116 
117 	return IRQ_HANDLED;
118 }
119 
120 static irqreturn_t sh_rtc_alarm(int irq, void *dev_id)
121 {
122 	struct platform_device *pdev = to_platform_device(dev_id);
123 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
124 	unsigned int tmp, events = 0;
125 
126 	spin_lock(&rtc->lock);
127 
128 	tmp = readb(rtc->regbase + RCR1);
129 
130 	/*
131 	 * If AF is set then the alarm has triggered. If we clear AF while
132 	 * the alarm time still matches the RTC time then AF will
133 	 * immediately be set again, and if AIE is enabled then the alarm
134 	 * interrupt will immediately be retrigger. So we clear AIE here
135 	 * and use rtc->rearm_aie so that the carry interrupt will keep
136 	 * trying to clear AF and once it stays cleared it'll re-enable
137 	 * AIE.
138 	 */
139 	if (tmp & RCR1_AF) {
140 		events |= RTC_AF | RTC_IRQF;
141 
142 		tmp &= ~(RCR1_AF|RCR1_AIE);
143 
144 		writeb(tmp, rtc->regbase + RCR1);
145 
146 		rtc->rearm_aie = 1;
147 
148 		rtc_update_irq(rtc->rtc_dev, 1, events);
149 	}
150 
151 	spin_unlock(&rtc->lock);
152 	return IRQ_HANDLED;
153 }
154 
155 static irqreturn_t sh_rtc_periodic(int irq, void *dev_id)
156 {
157 	struct platform_device *pdev = to_platform_device(dev_id);
158 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
159 
160 	spin_lock(&rtc->lock);
161 
162 	rtc_update_irq(rtc->rtc_dev, 1, RTC_PF | RTC_IRQF);
163 
164 	spin_unlock(&rtc->lock);
165 
166 	return IRQ_HANDLED;
167 }
168 
169 static inline void sh_rtc_setpie(struct device *dev, unsigned int enable)
170 {
171 	struct sh_rtc *rtc = dev_get_drvdata(dev);
172 	unsigned int tmp;
173 
174 	spin_lock_irq(&rtc->lock);
175 
176 	tmp = readb(rtc->regbase + RCR2);
177 
178 	if (enable) {
179 		tmp &= ~RCR2_PESMASK;
180 		tmp |= RCR2_PEF | (2 << 4);
181 	} else
182 		tmp &= ~(RCR2_PESMASK | RCR2_PEF);
183 
184 	writeb(tmp, rtc->regbase + RCR2);
185 
186 	spin_unlock_irq(&rtc->lock);
187 }
188 
189 static inline void sh_rtc_setaie(struct device *dev, unsigned int enable)
190 {
191 	struct sh_rtc *rtc = dev_get_drvdata(dev);
192 	unsigned int tmp;
193 
194 	spin_lock_irq(&rtc->lock);
195 
196 	tmp = readb(rtc->regbase + RCR1);
197 
198 	if (!enable) {
199 		tmp &= ~RCR1_AIE;
200 		rtc->rearm_aie = 0;
201 	} else if (rtc->rearm_aie == 0)
202 		tmp |= RCR1_AIE;
203 
204 	writeb(tmp, rtc->regbase + RCR1);
205 
206 	spin_unlock_irq(&rtc->lock);
207 }
208 
209 static int sh_rtc_open(struct device *dev)
210 {
211 	struct sh_rtc *rtc = dev_get_drvdata(dev);
212 	unsigned int tmp;
213 	int ret;
214 
215 	tmp = readb(rtc->regbase + RCR1);
216 	tmp &= ~RCR1_CF;
217 	tmp |= RCR1_CIE;
218 	writeb(tmp, rtc->regbase + RCR1);
219 
220 	ret = request_irq(rtc->periodic_irq, sh_rtc_periodic, IRQF_DISABLED,
221 			  "sh-rtc period", dev);
222 	if (unlikely(ret)) {
223 		dev_err(dev, "request period IRQ failed with %d, IRQ %d\n",
224 			ret, rtc->periodic_irq);
225 		return ret;
226 	}
227 
228 	ret = request_irq(rtc->carry_irq, sh_rtc_interrupt, IRQF_DISABLED,
229 			  "sh-rtc carry", dev);
230 	if (unlikely(ret)) {
231 		dev_err(dev, "request carry IRQ failed with %d, IRQ %d\n",
232 			ret, rtc->carry_irq);
233 		free_irq(rtc->periodic_irq, dev);
234 		goto err_bad_carry;
235 	}
236 
237 	ret = request_irq(rtc->alarm_irq, sh_rtc_alarm, IRQF_DISABLED,
238 			  "sh-rtc alarm", dev);
239 	if (unlikely(ret)) {
240 		dev_err(dev, "request alarm IRQ failed with %d, IRQ %d\n",
241 			ret, rtc->alarm_irq);
242 		goto err_bad_alarm;
243 	}
244 
245 	return 0;
246 
247 err_bad_alarm:
248 	free_irq(rtc->carry_irq, dev);
249 err_bad_carry:
250 	free_irq(rtc->periodic_irq, dev);
251 
252 	return ret;
253 }
254 
255 static void sh_rtc_release(struct device *dev)
256 {
257 	struct sh_rtc *rtc = dev_get_drvdata(dev);
258 
259 	sh_rtc_setpie(dev, 0);
260 	sh_rtc_setaie(dev, 0);
261 
262 	free_irq(rtc->periodic_irq, dev);
263 	free_irq(rtc->carry_irq, dev);
264 	free_irq(rtc->alarm_irq, dev);
265 }
266 
267 static int sh_rtc_proc(struct device *dev, struct seq_file *seq)
268 {
269 	struct sh_rtc *rtc = dev_get_drvdata(dev);
270 	unsigned int tmp;
271 
272 	tmp = readb(rtc->regbase + RCR1);
273 	seq_printf(seq, "carry_IRQ\t: %s\n",
274 		   (tmp & RCR1_CIE) ? "yes" : "no");
275 
276 	tmp = readb(rtc->regbase + RCR2);
277 	seq_printf(seq, "periodic_IRQ\t: %s\n",
278 		   (tmp & RCR2_PEF) ? "yes" : "no");
279 
280 	return 0;
281 }
282 
283 static int sh_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
284 {
285 	unsigned int ret = -ENOIOCTLCMD;
286 
287 	switch (cmd) {
288 	case RTC_PIE_OFF:
289 	case RTC_PIE_ON:
290 		sh_rtc_setpie(dev, cmd == RTC_PIE_ON);
291 		ret = 0;
292 		break;
293 	case RTC_AIE_OFF:
294 	case RTC_AIE_ON:
295 		sh_rtc_setaie(dev, cmd == RTC_AIE_ON);
296 		ret = 0;
297 		break;
298 	}
299 
300 	return ret;
301 }
302 
303 static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm)
304 {
305 	struct platform_device *pdev = to_platform_device(dev);
306 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
307 	unsigned int sec128, sec2, yr, yr100, cf_bit;
308 
309 	do {
310 		unsigned int tmp;
311 
312 		spin_lock_irq(&rtc->lock);
313 
314 		tmp = readb(rtc->regbase + RCR1);
315 		tmp &= ~RCR1_CF; /* Clear CF-bit */
316 		tmp |= RCR1_CIE;
317 		writeb(tmp, rtc->regbase + RCR1);
318 
319 		sec128 = readb(rtc->regbase + R64CNT);
320 
321 		tm->tm_sec	= BCD2BIN(readb(rtc->regbase + RSECCNT));
322 		tm->tm_min	= BCD2BIN(readb(rtc->regbase + RMINCNT));
323 		tm->tm_hour	= BCD2BIN(readb(rtc->regbase + RHRCNT));
324 		tm->tm_wday	= BCD2BIN(readb(rtc->regbase + RWKCNT));
325 		tm->tm_mday	= BCD2BIN(readb(rtc->regbase + RDAYCNT));
326 		tm->tm_mon	= BCD2BIN(readb(rtc->regbase + RMONCNT)) - 1;
327 
328 		if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
329 			yr  = readw(rtc->regbase + RYRCNT);
330 			yr100 = BCD2BIN(yr >> 8);
331 			yr &= 0xff;
332 		} else {
333 			yr  = readb(rtc->regbase + RYRCNT);
334 			yr100 = BCD2BIN((yr == 0x99) ? 0x19 : 0x20);
335 		}
336 
337 		tm->tm_year = (yr100 * 100 + BCD2BIN(yr)) - 1900;
338 
339 		sec2 = readb(rtc->regbase + R64CNT);
340 		cf_bit = readb(rtc->regbase + RCR1) & RCR1_CF;
341 
342 		spin_unlock_irq(&rtc->lock);
343 	} while (cf_bit != 0 || ((sec128 ^ sec2) & RTC_BIT_INVERTED) != 0);
344 
345 #if RTC_BIT_INVERTED != 0
346 	if ((sec128 & RTC_BIT_INVERTED))
347 		tm->tm_sec--;
348 #endif
349 
350 	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
351 		"mday=%d, mon=%d, year=%d, wday=%d\n",
352 		__FUNCTION__,
353 		tm->tm_sec, tm->tm_min, tm->tm_hour,
354 		tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
355 
356 	if (rtc_valid_tm(tm) < 0) {
357 		dev_err(dev, "invalid date\n");
358 		rtc_time_to_tm(0, tm);
359 	}
360 
361 	return 0;
362 }
363 
364 static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm)
365 {
366 	struct platform_device *pdev = to_platform_device(dev);
367 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
368 	unsigned int tmp;
369 	int year;
370 
371 	spin_lock_irq(&rtc->lock);
372 
373 	/* Reset pre-scaler & stop RTC */
374 	tmp = readb(rtc->regbase + RCR2);
375 	tmp |= RCR2_RESET;
376 	tmp &= ~RCR2_START;
377 	writeb(tmp, rtc->regbase + RCR2);
378 
379 	writeb(BIN2BCD(tm->tm_sec),  rtc->regbase + RSECCNT);
380 	writeb(BIN2BCD(tm->tm_min),  rtc->regbase + RMINCNT);
381 	writeb(BIN2BCD(tm->tm_hour), rtc->regbase + RHRCNT);
382 	writeb(BIN2BCD(tm->tm_wday), rtc->regbase + RWKCNT);
383 	writeb(BIN2BCD(tm->tm_mday), rtc->regbase + RDAYCNT);
384 	writeb(BIN2BCD(tm->tm_mon + 1), rtc->regbase + RMONCNT);
385 
386 	if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
387 		year = (BIN2BCD((tm->tm_year + 1900) / 100) << 8) |
388 			BIN2BCD(tm->tm_year % 100);
389 		writew(year, rtc->regbase + RYRCNT);
390 	} else {
391 		year = tm->tm_year % 100;
392 		writeb(BIN2BCD(year), rtc->regbase + RYRCNT);
393 	}
394 
395 	/* Start RTC */
396 	tmp = readb(rtc->regbase + RCR2);
397 	tmp &= ~RCR2_RESET;
398 	tmp |= RCR2_RTCEN | RCR2_START;
399 	writeb(tmp, rtc->regbase + RCR2);
400 
401 	spin_unlock_irq(&rtc->lock);
402 
403 	return 0;
404 }
405 
406 static inline int sh_rtc_read_alarm_value(struct sh_rtc *rtc, int reg_off)
407 {
408 	unsigned int byte;
409 	int value = 0xff;	/* return 0xff for ignored values */
410 
411 	byte = readb(rtc->regbase + reg_off);
412 	if (byte & AR_ENB) {
413 		byte &= ~AR_ENB;	/* strip the enable bit */
414 		value = BCD2BIN(byte);
415 	}
416 
417 	return value;
418 }
419 
420 static int sh_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
421 {
422 	struct platform_device *pdev = to_platform_device(dev);
423 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
424 	struct rtc_time* tm = &wkalrm->time;
425 
426 	spin_lock_irq(&rtc->lock);
427 
428 	tm->tm_sec	= sh_rtc_read_alarm_value(rtc, RSECAR);
429 	tm->tm_min	= sh_rtc_read_alarm_value(rtc, RMINAR);
430 	tm->tm_hour	= sh_rtc_read_alarm_value(rtc, RHRAR);
431 	tm->tm_wday	= sh_rtc_read_alarm_value(rtc, RWKAR);
432 	tm->tm_mday	= sh_rtc_read_alarm_value(rtc, RDAYAR);
433 	tm->tm_mon	= sh_rtc_read_alarm_value(rtc, RMONAR);
434 	if (tm->tm_mon > 0)
435 		tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */
436 	tm->tm_year     = 0xffff;
437 
438 	wkalrm->enabled = (readb(rtc->regbase + RCR1) & RCR1_AIE) ? 1 : 0;
439 
440 	spin_unlock_irq(&rtc->lock);
441 
442 	return 0;
443 }
444 
445 static inline void sh_rtc_write_alarm_value(struct sh_rtc *rtc,
446 					    int value, int reg_off)
447 {
448 	/* < 0 for a value that is ignored */
449 	if (value < 0)
450 		writeb(0, rtc->regbase + reg_off);
451 	else
452 		writeb(BIN2BCD(value) | AR_ENB,  rtc->regbase + reg_off);
453 }
454 
455 static int sh_rtc_check_alarm(struct rtc_time* tm)
456 {
457 	/*
458 	 * The original rtc says anything > 0xc0 is "don't care" or "match
459 	 * all" - most users use 0xff but rtc-dev uses -1 for the same thing.
460 	 * The original rtc doesn't support years - some things use -1 and
461 	 * some 0xffff. We use -1 to make out tests easier.
462 	 */
463 	if (tm->tm_year == 0xffff)
464 		tm->tm_year = -1;
465 	if (tm->tm_mon >= 0xff)
466 		tm->tm_mon = -1;
467 	if (tm->tm_mday >= 0xff)
468 		tm->tm_mday = -1;
469 	if (tm->tm_wday >= 0xff)
470 		tm->tm_wday = -1;
471 	if (tm->tm_hour >= 0xff)
472 		tm->tm_hour = -1;
473 	if (tm->tm_min >= 0xff)
474 		tm->tm_min = -1;
475 	if (tm->tm_sec >= 0xff)
476 		tm->tm_sec = -1;
477 
478 	if (tm->tm_year > 9999 ||
479 		tm->tm_mon >= 12 ||
480 		tm->tm_mday == 0 || tm->tm_mday >= 32 ||
481 		tm->tm_wday >= 7 ||
482 		tm->tm_hour >= 24 ||
483 		tm->tm_min >= 60 ||
484 		tm->tm_sec >= 60)
485 		return -EINVAL;
486 
487 	return 0;
488 }
489 
490 static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
491 {
492 	struct platform_device *pdev = to_platform_device(dev);
493 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
494 	unsigned int rcr1;
495 	struct rtc_time *tm = &wkalrm->time;
496 	int mon, err;
497 
498 	err = sh_rtc_check_alarm(tm);
499 	if (unlikely(err < 0))
500 		return err;
501 
502 	spin_lock_irq(&rtc->lock);
503 
504 	/* disable alarm interrupt and clear the alarm flag */
505 	rcr1 = readb(rtc->regbase + RCR1);
506 	rcr1 &= ~(RCR1_AF|RCR1_AIE);
507 	writeb(rcr1, rtc->regbase + RCR1);
508 
509 	rtc->rearm_aie = 0;
510 
511 	/* set alarm time */
512 	sh_rtc_write_alarm_value(rtc, tm->tm_sec,  RSECAR);
513 	sh_rtc_write_alarm_value(rtc, tm->tm_min,  RMINAR);
514 	sh_rtc_write_alarm_value(rtc, tm->tm_hour, RHRAR);
515 	sh_rtc_write_alarm_value(rtc, tm->tm_wday, RWKAR);
516 	sh_rtc_write_alarm_value(rtc, tm->tm_mday, RDAYAR);
517 	mon = tm->tm_mon;
518 	if (mon >= 0)
519 		mon += 1;
520 	sh_rtc_write_alarm_value(rtc, mon, RMONAR);
521 
522 	if (wkalrm->enabled) {
523 		rcr1 |= RCR1_AIE;
524 		writeb(rcr1, rtc->regbase + RCR1);
525 	}
526 
527 	spin_unlock_irq(&rtc->lock);
528 
529 	return 0;
530 }
531 
532 static struct rtc_class_ops sh_rtc_ops = {
533 	.open		= sh_rtc_open,
534 	.release	= sh_rtc_release,
535 	.ioctl		= sh_rtc_ioctl,
536 	.read_time	= sh_rtc_read_time,
537 	.set_time	= sh_rtc_set_time,
538 	.read_alarm	= sh_rtc_read_alarm,
539 	.set_alarm	= sh_rtc_set_alarm,
540 	.proc		= sh_rtc_proc,
541 };
542 
543 static int __devinit sh_rtc_probe(struct platform_device *pdev)
544 {
545 	struct sh_rtc *rtc;
546 	struct resource *res;
547 	int ret = -ENOENT;
548 
549 	rtc = kzalloc(sizeof(struct sh_rtc), GFP_KERNEL);
550 	if (unlikely(!rtc))
551 		return -ENOMEM;
552 
553 	spin_lock_init(&rtc->lock);
554 
555 	rtc->periodic_irq = platform_get_irq(pdev, 0);
556 	if (unlikely(rtc->periodic_irq < 0)) {
557 		dev_err(&pdev->dev, "No IRQ for period\n");
558 		goto err_badres;
559 	}
560 
561 	rtc->carry_irq = platform_get_irq(pdev, 1);
562 	if (unlikely(rtc->carry_irq < 0)) {
563 		dev_err(&pdev->dev, "No IRQ for carry\n");
564 		goto err_badres;
565 	}
566 
567 	rtc->alarm_irq = platform_get_irq(pdev, 2);
568 	if (unlikely(rtc->alarm_irq < 0)) {
569 		dev_err(&pdev->dev, "No IRQ for alarm\n");
570 		goto err_badres;
571 	}
572 
573 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
574 	if (unlikely(res == NULL)) {
575 		dev_err(&pdev->dev, "No IO resource\n");
576 		goto err_badres;
577 	}
578 
579 	rtc->regsize = res->end - res->start + 1;
580 
581 	rtc->res = request_mem_region(res->start, rtc->regsize, pdev->name);
582 	if (unlikely(!rtc->res)) {
583 		ret = -EBUSY;
584 		goto err_badres;
585 	}
586 
587 	rtc->regbase = (void __iomem *)rtc->res->start;
588 	if (unlikely(!rtc->regbase)) {
589 		ret = -EINVAL;
590 		goto err_badmap;
591 	}
592 
593 	rtc->rtc_dev = rtc_device_register("sh", &pdev->dev,
594 					   &sh_rtc_ops, THIS_MODULE);
595 	if (IS_ERR(rtc->rtc_dev)) {
596 		ret = PTR_ERR(rtc->rtc_dev);
597 		goto err_badmap;
598 	}
599 
600 	rtc->capabilities = RTC_DEF_CAPABILITIES;
601 	if (pdev->dev.platform_data) {
602 		struct sh_rtc_platform_info *pinfo = pdev->dev.platform_data;
603 
604 		/*
605 		 * Some CPUs have special capabilities in addition to the
606 		 * default set. Add those in here.
607 		 */
608 		rtc->capabilities |= pinfo->capabilities;
609 	}
610 
611 	platform_set_drvdata(pdev, rtc);
612 
613 	return 0;
614 
615 err_badmap:
616 	release_resource(rtc->res);
617 err_badres:
618 	kfree(rtc);
619 
620 	return ret;
621 }
622 
623 static int __devexit sh_rtc_remove(struct platform_device *pdev)
624 {
625 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
626 
627 	if (likely(rtc->rtc_dev))
628 		rtc_device_unregister(rtc->rtc_dev);
629 
630 	sh_rtc_setpie(&pdev->dev, 0);
631 	sh_rtc_setaie(&pdev->dev, 0);
632 
633 	release_resource(rtc->res);
634 
635 	platform_set_drvdata(pdev, NULL);
636 
637 	kfree(rtc);
638 
639 	return 0;
640 }
641 static struct platform_driver sh_rtc_platform_driver = {
642 	.driver		= {
643 		.name	= DRV_NAME,
644 		.owner	= THIS_MODULE,
645 	},
646 	.probe		= sh_rtc_probe,
647 	.remove		= __devexit_p(sh_rtc_remove),
648 };
649 
650 static int __init sh_rtc_init(void)
651 {
652 	return platform_driver_register(&sh_rtc_platform_driver);
653 }
654 
655 static void __exit sh_rtc_exit(void)
656 {
657 	platform_driver_unregister(&sh_rtc_platform_driver);
658 }
659 
660 module_init(sh_rtc_init);
661 module_exit(sh_rtc_exit);
662 
663 MODULE_DESCRIPTION("SuperH on-chip RTC driver");
664 MODULE_VERSION(DRV_VERSION);
665 MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, Jamie Lenehan <lenehan@twibble.org>");
666 MODULE_LICENSE("GPL");
667