xref: /openbmc/linux/drivers/rtc/rtc-sh.c (revision ad89f87a84040a57c4a78ca2759b364f72f423ab)
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	"0.1.3"
30 
31 #ifdef CONFIG_CPU_SH3
32 #define rtc_reg_size		sizeof(u16)
33 #define RTC_BIT_INVERTED	0	/* No bug on SH7708, SH7709A */
34 #define RTC_DEF_CAPABILITIES	0UL
35 #elif defined(CONFIG_CPU_SH4)
36 #define rtc_reg_size		sizeof(u32)
37 #define RTC_BIT_INVERTED	0x40	/* bug on SH7750, SH7750S */
38 #define RTC_DEF_CAPABILITIES	RTC_CAP_4_DIGIT_YEAR
39 #endif
40 
41 #define RTC_REG(r)	((r) * rtc_reg_size)
42 
43 #define R64CNT		RTC_REG(0)
44 
45 #define RSECCNT		RTC_REG(1)	/* RTC sec */
46 #define RMINCNT		RTC_REG(2)	/* RTC min */
47 #define RHRCNT		RTC_REG(3)	/* RTC hour */
48 #define RWKCNT		RTC_REG(4)	/* RTC week */
49 #define RDAYCNT		RTC_REG(5)	/* RTC day */
50 #define RMONCNT		RTC_REG(6)	/* RTC month */
51 #define RYRCNT		RTC_REG(7)	/* RTC year */
52 #define RSECAR		RTC_REG(8)	/* ALARM sec */
53 #define RMINAR		RTC_REG(9)	/* ALARM min */
54 #define RHRAR		RTC_REG(10)	/* ALARM hour */
55 #define RWKAR		RTC_REG(11)	/* ALARM week */
56 #define RDAYAR		RTC_REG(12)	/* ALARM day */
57 #define RMONAR		RTC_REG(13)	/* ALARM month */
58 #define RCR1		RTC_REG(14)	/* Control */
59 #define RCR2		RTC_REG(15)	/* Control */
60 
61 /* ALARM Bits - or with BCD encoded value */
62 #define AR_ENB		0x80	/* Enable for alarm cmp   */
63 
64 /* RCR1 Bits */
65 #define RCR1_CF		0x80	/* Carry Flag             */
66 #define RCR1_CIE	0x10	/* Carry Interrupt Enable */
67 #define RCR1_AIE	0x08	/* Alarm Interrupt Enable */
68 #define RCR1_AF		0x01	/* Alarm Flag             */
69 
70 /* RCR2 Bits */
71 #define RCR2_PEF	0x80	/* PEriodic interrupt Flag */
72 #define RCR2_PESMASK	0x70	/* Periodic interrupt Set  */
73 #define RCR2_RTCEN	0x08	/* ENable RTC              */
74 #define RCR2_ADJ	0x04	/* ADJustment (30-second)  */
75 #define RCR2_RESET	0x02	/* Reset bit               */
76 #define RCR2_START	0x01	/* Start bit               */
77 
78 struct sh_rtc {
79 	void __iomem *regbase;
80 	unsigned long regsize;
81 	struct resource *res;
82 	unsigned int alarm_irq, periodic_irq, carry_irq;
83 	struct rtc_device *rtc_dev;
84 	spinlock_t lock;
85 	int rearm_aie;
86 	unsigned long capabilities;	/* See asm-sh/rtc.h for cap bits */
87 };
88 
89 static irqreturn_t sh_rtc_interrupt(int irq, void *dev_id)
90 {
91 	struct platform_device *pdev = to_platform_device(dev_id);
92 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
93 	unsigned int tmp, events = 0;
94 
95 	spin_lock(&rtc->lock);
96 
97 	tmp = readb(rtc->regbase + RCR1);
98 	tmp &= ~RCR1_CF;
99 
100 	if (rtc->rearm_aie) {
101 		if (tmp & RCR1_AF)
102 			tmp &= ~RCR1_AF;	/* try to clear AF again */
103 		else {
104 			tmp |= RCR1_AIE;	/* AF has cleared, rearm IRQ */
105 			rtc->rearm_aie = 0;
106 		}
107 	}
108 
109 	writeb(tmp, rtc->regbase + RCR1);
110 
111 	rtc_update_irq(rtc->rtc_dev, 1, events);
112 
113 	spin_unlock(&rtc->lock);
114 
115 	return IRQ_HANDLED;
116 }
117 
118 static irqreturn_t sh_rtc_alarm(int irq, void *dev_id)
119 {
120 	struct platform_device *pdev = to_platform_device(dev_id);
121 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
122 	unsigned int tmp, events = 0;
123 
124 	spin_lock(&rtc->lock);
125 
126 	tmp = readb(rtc->regbase + RCR1);
127 
128 	/*
129 	 * If AF is set then the alarm has triggered. If we clear AF while
130 	 * the alarm time still matches the RTC time then AF will
131 	 * immediately be set again, and if AIE is enabled then the alarm
132 	 * interrupt will immediately be retrigger. So we clear AIE here
133 	 * and use rtc->rearm_aie so that the carry interrupt will keep
134 	 * trying to clear AF and once it stays cleared it'll re-enable
135 	 * AIE.
136 	 */
137 	if (tmp & RCR1_AF) {
138 		events |= RTC_AF | RTC_IRQF;
139 
140 		tmp &= ~(RCR1_AF|RCR1_AIE);
141 
142 		writeb(tmp, rtc->regbase + RCR1);
143 
144 		rtc->rearm_aie = 1;
145 
146 		rtc_update_irq(rtc->rtc_dev, 1, events);
147 	}
148 
149 	spin_unlock(&rtc->lock);
150 	return IRQ_HANDLED;
151 }
152 
153 static irqreturn_t sh_rtc_periodic(int irq, void *dev_id)
154 {
155 	struct platform_device *pdev = to_platform_device(dev_id);
156 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
157 
158 	spin_lock(&rtc->lock);
159 
160 	rtc_update_irq(rtc->rtc_dev, 1, RTC_PF | RTC_IRQF);
161 
162 	spin_unlock(&rtc->lock);
163 
164 	return IRQ_HANDLED;
165 }
166 
167 static inline void sh_rtc_setpie(struct device *dev, unsigned int enable)
168 {
169 	struct sh_rtc *rtc = dev_get_drvdata(dev);
170 	unsigned int tmp;
171 
172 	spin_lock_irq(&rtc->lock);
173 
174 	tmp = readb(rtc->regbase + RCR2);
175 
176 	if (enable) {
177 		tmp &= ~RCR2_PESMASK;
178 		tmp |= RCR2_PEF | (2 << 4);
179 	} else
180 		tmp &= ~(RCR2_PESMASK | RCR2_PEF);
181 
182 	writeb(tmp, rtc->regbase + RCR2);
183 
184 	spin_unlock_irq(&rtc->lock);
185 }
186 
187 static inline void sh_rtc_setaie(struct device *dev, unsigned int enable)
188 {
189 	struct sh_rtc *rtc = dev_get_drvdata(dev);
190 	unsigned int tmp;
191 
192 	spin_lock_irq(&rtc->lock);
193 
194 	tmp = readb(rtc->regbase + RCR1);
195 
196 	if (!enable) {
197 		tmp &= ~RCR1_AIE;
198 		rtc->rearm_aie = 0;
199 	} else if (rtc->rearm_aie == 0)
200 		tmp |= RCR1_AIE;
201 
202 	writeb(tmp, rtc->regbase + RCR1);
203 
204 	spin_unlock_irq(&rtc->lock);
205 }
206 
207 static int sh_rtc_open(struct device *dev)
208 {
209 	struct sh_rtc *rtc = dev_get_drvdata(dev);
210 	unsigned int tmp;
211 	int ret;
212 
213 	tmp = readb(rtc->regbase + RCR1);
214 	tmp &= ~RCR1_CF;
215 	tmp |= RCR1_CIE;
216 	writeb(tmp, rtc->regbase + RCR1);
217 
218 	ret = request_irq(rtc->periodic_irq, sh_rtc_periodic, IRQF_DISABLED,
219 			  "sh-rtc period", dev);
220 	if (unlikely(ret)) {
221 		dev_err(dev, "request period IRQ failed with %d, IRQ %d\n",
222 			ret, rtc->periodic_irq);
223 		return ret;
224 	}
225 
226 	ret = request_irq(rtc->carry_irq, sh_rtc_interrupt, IRQF_DISABLED,
227 			  "sh-rtc carry", dev);
228 	if (unlikely(ret)) {
229 		dev_err(dev, "request carry IRQ failed with %d, IRQ %d\n",
230 			ret, rtc->carry_irq);
231 		free_irq(rtc->periodic_irq, dev);
232 		goto err_bad_carry;
233 	}
234 
235 	ret = request_irq(rtc->alarm_irq, sh_rtc_alarm, IRQF_DISABLED,
236 			  "sh-rtc alarm", dev);
237 	if (unlikely(ret)) {
238 		dev_err(dev, "request alarm IRQ failed with %d, IRQ %d\n",
239 			ret, rtc->alarm_irq);
240 		goto err_bad_alarm;
241 	}
242 
243 	return 0;
244 
245 err_bad_alarm:
246 	free_irq(rtc->carry_irq, dev);
247 err_bad_carry:
248 	free_irq(rtc->periodic_irq, dev);
249 
250 	return ret;
251 }
252 
253 static void sh_rtc_release(struct device *dev)
254 {
255 	struct sh_rtc *rtc = dev_get_drvdata(dev);
256 
257 	sh_rtc_setpie(dev, 0);
258 	sh_rtc_setaie(dev, 0);
259 
260 	free_irq(rtc->periodic_irq, dev);
261 	free_irq(rtc->carry_irq, dev);
262 	free_irq(rtc->alarm_irq, dev);
263 }
264 
265 static int sh_rtc_proc(struct device *dev, struct seq_file *seq)
266 {
267 	struct sh_rtc *rtc = dev_get_drvdata(dev);
268 	unsigned int tmp;
269 
270 	tmp = readb(rtc->regbase + RCR1);
271 	seq_printf(seq, "carry_IRQ\t: %s\n",
272 		   (tmp & RCR1_CIE) ? "yes" : "no");
273 
274 	tmp = readb(rtc->regbase + RCR2);
275 	seq_printf(seq, "periodic_IRQ\t: %s\n",
276 		   (tmp & RCR2_PEF) ? "yes" : "no");
277 
278 	return 0;
279 }
280 
281 static int sh_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
282 {
283 	unsigned int ret = -ENOIOCTLCMD;
284 
285 	switch (cmd) {
286 	case RTC_PIE_OFF:
287 	case RTC_PIE_ON:
288 		sh_rtc_setpie(dev, cmd == RTC_PIE_ON);
289 		ret = 0;
290 		break;
291 	case RTC_AIE_OFF:
292 	case RTC_AIE_ON:
293 		sh_rtc_setaie(dev, cmd == RTC_AIE_ON);
294 		ret = 0;
295 		break;
296 	}
297 
298 	return ret;
299 }
300 
301 static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm)
302 {
303 	struct platform_device *pdev = to_platform_device(dev);
304 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
305 	unsigned int sec128, sec2, yr, yr100, cf_bit;
306 
307 	do {
308 		unsigned int tmp;
309 
310 		spin_lock_irq(&rtc->lock);
311 
312 		tmp = readb(rtc->regbase + RCR1);
313 		tmp &= ~RCR1_CF; /* Clear CF-bit */
314 		tmp |= RCR1_CIE;
315 		writeb(tmp, rtc->regbase + RCR1);
316 
317 		sec128 = readb(rtc->regbase + R64CNT);
318 
319 		tm->tm_sec	= BCD2BIN(readb(rtc->regbase + RSECCNT));
320 		tm->tm_min	= BCD2BIN(readb(rtc->regbase + RMINCNT));
321 		tm->tm_hour	= BCD2BIN(readb(rtc->regbase + RHRCNT));
322 		tm->tm_wday	= BCD2BIN(readb(rtc->regbase + RWKCNT));
323 		tm->tm_mday	= BCD2BIN(readb(rtc->regbase + RDAYCNT));
324 		tm->tm_mon	= BCD2BIN(readb(rtc->regbase + RMONCNT)) - 1;
325 
326 		if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
327 			yr  = readw(rtc->regbase + RYRCNT);
328 			yr100 = BCD2BIN(yr >> 8);
329 			yr &= 0xff;
330 		} else {
331 			yr  = readb(rtc->regbase + RYRCNT);
332 			yr100 = BCD2BIN((yr == 0x99) ? 0x19 : 0x20);
333 		}
334 
335 		tm->tm_year = (yr100 * 100 + BCD2BIN(yr)) - 1900;
336 
337 		sec2 = readb(rtc->regbase + R64CNT);
338 		cf_bit = readb(rtc->regbase + RCR1) & RCR1_CF;
339 
340 		spin_unlock_irq(&rtc->lock);
341 	} while (cf_bit != 0 || ((sec128 ^ sec2) & RTC_BIT_INVERTED) != 0);
342 
343 #if RTC_BIT_INVERTED != 0
344 	if ((sec128 & RTC_BIT_INVERTED))
345 		tm->tm_sec--;
346 #endif
347 
348 	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
349 		"mday=%d, mon=%d, year=%d, wday=%d\n",
350 		__FUNCTION__,
351 		tm->tm_sec, tm->tm_min, tm->tm_hour,
352 		tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
353 
354 	if (rtc_valid_tm(tm) < 0)
355 		dev_err(dev, "invalid date\n");
356 
357 	return 0;
358 }
359 
360 static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm)
361 {
362 	struct platform_device *pdev = to_platform_device(dev);
363 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
364 	unsigned int tmp;
365 	int year;
366 
367 	spin_lock_irq(&rtc->lock);
368 
369 	/* Reset pre-scaler & stop RTC */
370 	tmp = readb(rtc->regbase + RCR2);
371 	tmp |= RCR2_RESET;
372 	tmp &= ~RCR2_START;
373 	writeb(tmp, rtc->regbase + RCR2);
374 
375 	writeb(BIN2BCD(tm->tm_sec),  rtc->regbase + RSECCNT);
376 	writeb(BIN2BCD(tm->tm_min),  rtc->regbase + RMINCNT);
377 	writeb(BIN2BCD(tm->tm_hour), rtc->regbase + RHRCNT);
378 	writeb(BIN2BCD(tm->tm_wday), rtc->regbase + RWKCNT);
379 	writeb(BIN2BCD(tm->tm_mday), rtc->regbase + RDAYCNT);
380 	writeb(BIN2BCD(tm->tm_mon + 1), rtc->regbase + RMONCNT);
381 
382 	if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
383 		year = (BIN2BCD((tm->tm_year + 1900) / 100) << 8) |
384 			BIN2BCD(tm->tm_year % 100);
385 		writew(year, rtc->regbase + RYRCNT);
386 	} else {
387 		year = tm->tm_year % 100;
388 		writeb(BIN2BCD(year), rtc->regbase + RYRCNT);
389 	}
390 
391 	/* Start RTC */
392 	tmp = readb(rtc->regbase + RCR2);
393 	tmp &= ~RCR2_RESET;
394 	tmp |= RCR2_RTCEN | RCR2_START;
395 	writeb(tmp, rtc->regbase + RCR2);
396 
397 	spin_unlock_irq(&rtc->lock);
398 
399 	return 0;
400 }
401 
402 static inline int sh_rtc_read_alarm_value(struct sh_rtc *rtc, int reg_off)
403 {
404 	unsigned int byte;
405 	int value = 0xff;	/* return 0xff for ignored values */
406 
407 	byte = readb(rtc->regbase + reg_off);
408 	if (byte & AR_ENB) {
409 		byte &= ~AR_ENB;	/* strip the enable bit */
410 		value = BCD2BIN(byte);
411 	}
412 
413 	return value;
414 }
415 
416 static int sh_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
417 {
418 	struct platform_device *pdev = to_platform_device(dev);
419 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
420 	struct rtc_time* tm = &wkalrm->time;
421 
422 	spin_lock_irq(&rtc->lock);
423 
424 	tm->tm_sec	= sh_rtc_read_alarm_value(rtc, RSECAR);
425 	tm->tm_min	= sh_rtc_read_alarm_value(rtc, RMINAR);
426 	tm->tm_hour	= sh_rtc_read_alarm_value(rtc, RHRAR);
427 	tm->tm_wday	= sh_rtc_read_alarm_value(rtc, RWKAR);
428 	tm->tm_mday	= sh_rtc_read_alarm_value(rtc, RDAYAR);
429 	tm->tm_mon	= sh_rtc_read_alarm_value(rtc, RMONAR);
430 	if (tm->tm_mon > 0)
431 		tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */
432 	tm->tm_year     = 0xffff;
433 
434 	wkalrm->enabled = (readb(rtc->regbase + RCR1) & RCR1_AIE) ? 1 : 0;
435 
436 	spin_unlock_irq(&rtc->lock);
437 
438 	return 0;
439 }
440 
441 static inline void sh_rtc_write_alarm_value(struct sh_rtc *rtc,
442 					    int value, int reg_off)
443 {
444 	/* < 0 for a value that is ignored */
445 	if (value < 0)
446 		writeb(0, rtc->regbase + reg_off);
447 	else
448 		writeb(BIN2BCD(value) | AR_ENB,  rtc->regbase + reg_off);
449 }
450 
451 static int sh_rtc_check_alarm(struct rtc_time* tm)
452 {
453 	/*
454 	 * The original rtc says anything > 0xc0 is "don't care" or "match
455 	 * all" - most users use 0xff but rtc-dev uses -1 for the same thing.
456 	 * The original rtc doesn't support years - some things use -1 and
457 	 * some 0xffff. We use -1 to make out tests easier.
458 	 */
459 	if (tm->tm_year == 0xffff)
460 		tm->tm_year = -1;
461 	if (tm->tm_mon >= 0xff)
462 		tm->tm_mon = -1;
463 	if (tm->tm_mday >= 0xff)
464 		tm->tm_mday = -1;
465 	if (tm->tm_wday >= 0xff)
466 		tm->tm_wday = -1;
467 	if (tm->tm_hour >= 0xff)
468 		tm->tm_hour = -1;
469 	if (tm->tm_min >= 0xff)
470 		tm->tm_min = -1;
471 	if (tm->tm_sec >= 0xff)
472 		tm->tm_sec = -1;
473 
474 	if (tm->tm_year > 9999 ||
475 		tm->tm_mon >= 12 ||
476 		tm->tm_mday == 0 || tm->tm_mday >= 32 ||
477 		tm->tm_wday >= 7 ||
478 		tm->tm_hour >= 24 ||
479 		tm->tm_min >= 60 ||
480 		tm->tm_sec >= 60)
481 		return -EINVAL;
482 
483 	return 0;
484 }
485 
486 static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
487 {
488 	struct platform_device *pdev = to_platform_device(dev);
489 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
490 	unsigned int rcr1;
491 	struct rtc_time *tm = &wkalrm->time;
492 	int mon, err;
493 
494 	err = sh_rtc_check_alarm(tm);
495 	if (unlikely(err < 0))
496 		return err;
497 
498 	spin_lock_irq(&rtc->lock);
499 
500 	/* disable alarm interrupt and clear the alarm flag */
501 	rcr1 = readb(rtc->regbase + RCR1);
502 	rcr1 &= ~(RCR1_AF|RCR1_AIE);
503 	writeb(rcr1, rtc->regbase + RCR1);
504 
505 	rtc->rearm_aie = 0;
506 
507 	/* set alarm time */
508 	sh_rtc_write_alarm_value(rtc, tm->tm_sec,  RSECAR);
509 	sh_rtc_write_alarm_value(rtc, tm->tm_min,  RMINAR);
510 	sh_rtc_write_alarm_value(rtc, tm->tm_hour, RHRAR);
511 	sh_rtc_write_alarm_value(rtc, tm->tm_wday, RWKAR);
512 	sh_rtc_write_alarm_value(rtc, tm->tm_mday, RDAYAR);
513 	mon = tm->tm_mon;
514 	if (mon >= 0)
515 		mon += 1;
516 	sh_rtc_write_alarm_value(rtc, mon, RMONAR);
517 
518 	if (wkalrm->enabled) {
519 		rcr1 |= RCR1_AIE;
520 		writeb(rcr1, rtc->regbase + RCR1);
521 	}
522 
523 	spin_unlock_irq(&rtc->lock);
524 
525 	return 0;
526 }
527 
528 static struct rtc_class_ops sh_rtc_ops = {
529 	.open		= sh_rtc_open,
530 	.release	= sh_rtc_release,
531 	.ioctl		= sh_rtc_ioctl,
532 	.read_time	= sh_rtc_read_time,
533 	.set_time	= sh_rtc_set_time,
534 	.read_alarm	= sh_rtc_read_alarm,
535 	.set_alarm	= sh_rtc_set_alarm,
536 	.proc		= sh_rtc_proc,
537 };
538 
539 static int __devinit sh_rtc_probe(struct platform_device *pdev)
540 {
541 	struct sh_rtc *rtc;
542 	struct resource *res;
543 	int ret = -ENOENT;
544 
545 	rtc = kzalloc(sizeof(struct sh_rtc), GFP_KERNEL);
546 	if (unlikely(!rtc))
547 		return -ENOMEM;
548 
549 	spin_lock_init(&rtc->lock);
550 
551 	rtc->periodic_irq = platform_get_irq(pdev, 0);
552 	if (unlikely(rtc->periodic_irq < 0)) {
553 		dev_err(&pdev->dev, "No IRQ for period\n");
554 		goto err_badres;
555 	}
556 
557 	rtc->carry_irq = platform_get_irq(pdev, 1);
558 	if (unlikely(rtc->carry_irq < 0)) {
559 		dev_err(&pdev->dev, "No IRQ for carry\n");
560 		goto err_badres;
561 	}
562 
563 	rtc->alarm_irq = platform_get_irq(pdev, 2);
564 	if (unlikely(rtc->alarm_irq < 0)) {
565 		dev_err(&pdev->dev, "No IRQ for alarm\n");
566 		goto err_badres;
567 	}
568 
569 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
570 	if (unlikely(res == NULL)) {
571 		dev_err(&pdev->dev, "No IO resource\n");
572 		goto err_badres;
573 	}
574 
575 	rtc->regsize = res->end - res->start + 1;
576 
577 	rtc->res = request_mem_region(res->start, rtc->regsize, pdev->name);
578 	if (unlikely(!rtc->res)) {
579 		ret = -EBUSY;
580 		goto err_badres;
581 	}
582 
583 	rtc->regbase = (void __iomem *)rtc->res->start;
584 	if (unlikely(!rtc->regbase)) {
585 		ret = -EINVAL;
586 		goto err_badmap;
587 	}
588 
589 	rtc->rtc_dev = rtc_device_register("sh", &pdev->dev,
590 					   &sh_rtc_ops, THIS_MODULE);
591 	if (IS_ERR(rtc)) {
592 		ret = PTR_ERR(rtc->rtc_dev);
593 		goto err_badmap;
594 	}
595 
596 	rtc->capabilities = RTC_DEF_CAPABILITIES;
597 	if (pdev->dev.platform_data) {
598 		struct sh_rtc_platform_info *pinfo = pdev->dev.platform_data;
599 
600 		/*
601 		 * Some CPUs have special capabilities in addition to the
602 		 * default set. Add those in here.
603 		 */
604 		rtc->capabilities |= pinfo->capabilities;
605 	}
606 
607 	platform_set_drvdata(pdev, rtc);
608 
609 	return 0;
610 
611 err_badmap:
612 	release_resource(rtc->res);
613 err_badres:
614 	kfree(rtc);
615 
616 	return ret;
617 }
618 
619 static int __devexit sh_rtc_remove(struct platform_device *pdev)
620 {
621 	struct sh_rtc *rtc = platform_get_drvdata(pdev);
622 
623 	if (likely(rtc->rtc_dev))
624 		rtc_device_unregister(rtc->rtc_dev);
625 
626 	sh_rtc_setpie(&pdev->dev, 0);
627 	sh_rtc_setaie(&pdev->dev, 0);
628 
629 	release_resource(rtc->res);
630 
631 	platform_set_drvdata(pdev, NULL);
632 
633 	kfree(rtc);
634 
635 	return 0;
636 }
637 static struct platform_driver sh_rtc_platform_driver = {
638 	.driver		= {
639 		.name	= DRV_NAME,
640 		.owner	= THIS_MODULE,
641 	},
642 	.probe		= sh_rtc_probe,
643 	.remove		= __devexit_p(sh_rtc_remove),
644 };
645 
646 static int __init sh_rtc_init(void)
647 {
648 	return platform_driver_register(&sh_rtc_platform_driver);
649 }
650 
651 static void __exit sh_rtc_exit(void)
652 {
653 	platform_driver_unregister(&sh_rtc_platform_driver);
654 }
655 
656 module_init(sh_rtc_init);
657 module_exit(sh_rtc_exit);
658 
659 MODULE_DESCRIPTION("SuperH on-chip RTC driver");
660 MODULE_VERSION(DRV_VERSION);
661 MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, Jamie Lenehan <lenehan@twibble.org>");
662 MODULE_LICENSE("GPL");
663