Merge branch 'stable/for-jens-3.13-take-two' of git://git.kernel.org/pub/scm/linux...
[pandora-kernel.git] / drivers / rtc / rtc-sh.c
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 <linux/slab.h>
30 #include <asm/rtc.h>
31
32 #define DRV_NAME        "sh-rtc"
33 #define DRV_VERSION     "0.2.3"
34
35 #define RTC_REG(r)      ((r) * rtc_reg_size)
36
37 #define R64CNT          RTC_REG(0)
38
39 #define RSECCNT         RTC_REG(1)      /* RTC sec */
40 #define RMINCNT         RTC_REG(2)      /* RTC min */
41 #define RHRCNT          RTC_REG(3)      /* RTC hour */
42 #define RWKCNT          RTC_REG(4)      /* RTC week */
43 #define RDAYCNT         RTC_REG(5)      /* RTC day */
44 #define RMONCNT         RTC_REG(6)      /* RTC month */
45 #define RYRCNT          RTC_REG(7)      /* RTC year */
46 #define RSECAR          RTC_REG(8)      /* ALARM sec */
47 #define RMINAR          RTC_REG(9)      /* ALARM min */
48 #define RHRAR           RTC_REG(10)     /* ALARM hour */
49 #define RWKAR           RTC_REG(11)     /* ALARM week */
50 #define RDAYAR          RTC_REG(12)     /* ALARM day */
51 #define RMONAR          RTC_REG(13)     /* ALARM month */
52 #define RCR1            RTC_REG(14)     /* Control */
53 #define RCR2            RTC_REG(15)     /* Control */
54
55 /*
56  * Note on RYRAR and RCR3: Up until this point most of the register
57  * definitions are consistent across all of the available parts. However,
58  * the placement of the optional RYRAR and RCR3 (the RYRAR control
59  * register used to control RYRCNT/RYRAR compare) varies considerably
60  * across various parts, occasionally being mapped in to a completely
61  * unrelated address space. For proper RYRAR support a separate resource
62  * would have to be handed off, but as this is purely optional in
63  * practice, we simply opt not to support it, thereby keeping the code
64  * quite a bit more simplified.
65  */
66
67 /* ALARM Bits - or with BCD encoded value */
68 #define AR_ENB          0x80    /* Enable for alarm cmp   */
69
70 /* Period Bits */
71 #define PF_HP           0x100   /* Enable Half Period to support 8,32,128Hz */
72 #define PF_COUNT        0x200   /* Half periodic counter */
73 #define PF_OXS          0x400   /* Periodic One x Second */
74 #define PF_KOU          0x800   /* Kernel or User periodic request 1=kernel */
75 #define PF_MASK         0xf00
76
77 /* RCR1 Bits */
78 #define RCR1_CF         0x80    /* Carry Flag             */
79 #define RCR1_CIE        0x10    /* Carry Interrupt Enable */
80 #define RCR1_AIE        0x08    /* Alarm Interrupt Enable */
81 #define RCR1_AF         0x01    /* Alarm Flag             */
82
83 /* RCR2 Bits */
84 #define RCR2_PEF        0x80    /* PEriodic interrupt Flag */
85 #define RCR2_PESMASK    0x70    /* Periodic interrupt Set  */
86 #define RCR2_RTCEN      0x08    /* ENable RTC              */
87 #define RCR2_ADJ        0x04    /* ADJustment (30-second)  */
88 #define RCR2_RESET      0x02    /* Reset bit               */
89 #define RCR2_START      0x01    /* Start bit               */
90
91 struct sh_rtc {
92         void __iomem            *regbase;
93         unsigned long           regsize;
94         struct resource         *res;
95         int                     alarm_irq;
96         int                     periodic_irq;
97         int                     carry_irq;
98         struct clk              *clk;
99         struct rtc_device       *rtc_dev;
100         spinlock_t              lock;
101         unsigned long           capabilities;   /* See asm/rtc.h for cap bits */
102         unsigned short          periodic_freq;
103 };
104
105 static int __sh_rtc_interrupt(struct sh_rtc *rtc)
106 {
107         unsigned int tmp, pending;
108
109         tmp = readb(rtc->regbase + RCR1);
110         pending = tmp & RCR1_CF;
111         tmp &= ~RCR1_CF;
112         writeb(tmp, rtc->regbase + RCR1);
113
114         /* Users have requested One x Second IRQ */
115         if (pending && rtc->periodic_freq & PF_OXS)
116                 rtc_update_irq(rtc->rtc_dev, 1, RTC_UF | RTC_IRQF);
117
118         return pending;
119 }
120
121 static int __sh_rtc_alarm(struct sh_rtc *rtc)
122 {
123         unsigned int tmp, pending;
124
125         tmp = readb(rtc->regbase + RCR1);
126         pending = tmp & RCR1_AF;
127         tmp &= ~(RCR1_AF | RCR1_AIE);
128         writeb(tmp, rtc->regbase + RCR1);
129
130         if (pending)
131                 rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF);
132
133         return pending;
134 }
135
136 static int __sh_rtc_periodic(struct sh_rtc *rtc)
137 {
138         struct rtc_device *rtc_dev = rtc->rtc_dev;
139         struct rtc_task *irq_task;
140         unsigned int tmp, pending;
141
142         tmp = readb(rtc->regbase + RCR2);
143         pending = tmp & RCR2_PEF;
144         tmp &= ~RCR2_PEF;
145         writeb(tmp, rtc->regbase + RCR2);
146
147         if (!pending)
148                 return 0;
149
150         /* Half period enabled than one skipped and the next notified */
151         if ((rtc->periodic_freq & PF_HP) && (rtc->periodic_freq & PF_COUNT))
152                 rtc->periodic_freq &= ~PF_COUNT;
153         else {
154                 if (rtc->periodic_freq & PF_HP)
155                         rtc->periodic_freq |= PF_COUNT;
156                 if (rtc->periodic_freq & PF_KOU) {
157                         spin_lock(&rtc_dev->irq_task_lock);
158                         irq_task = rtc_dev->irq_task;
159                         if (irq_task)
160                                 irq_task->func(irq_task->private_data);
161                         spin_unlock(&rtc_dev->irq_task_lock);
162                 } else
163                         rtc_update_irq(rtc->rtc_dev, 1, RTC_PF | RTC_IRQF);
164         }
165
166         return pending;
167 }
168
169 static irqreturn_t sh_rtc_interrupt(int irq, void *dev_id)
170 {
171         struct sh_rtc *rtc = dev_id;
172         int ret;
173
174         spin_lock(&rtc->lock);
175         ret = __sh_rtc_interrupt(rtc);
176         spin_unlock(&rtc->lock);
177
178         return IRQ_RETVAL(ret);
179 }
180
181 static irqreturn_t sh_rtc_alarm(int irq, void *dev_id)
182 {
183         struct sh_rtc *rtc = dev_id;
184         int ret;
185
186         spin_lock(&rtc->lock);
187         ret = __sh_rtc_alarm(rtc);
188         spin_unlock(&rtc->lock);
189
190         return IRQ_RETVAL(ret);
191 }
192
193 static irqreturn_t sh_rtc_periodic(int irq, void *dev_id)
194 {
195         struct sh_rtc *rtc = dev_id;
196         int ret;
197
198         spin_lock(&rtc->lock);
199         ret = __sh_rtc_periodic(rtc);
200         spin_unlock(&rtc->lock);
201
202         return IRQ_RETVAL(ret);
203 }
204
205 static irqreturn_t sh_rtc_shared(int irq, void *dev_id)
206 {
207         struct sh_rtc *rtc = dev_id;
208         int ret;
209
210         spin_lock(&rtc->lock);
211         ret = __sh_rtc_interrupt(rtc);
212         ret |= __sh_rtc_alarm(rtc);
213         ret |= __sh_rtc_periodic(rtc);
214         spin_unlock(&rtc->lock);
215
216         return IRQ_RETVAL(ret);
217 }
218
219 static int sh_rtc_irq_set_state(struct device *dev, int enable)
220 {
221         struct sh_rtc *rtc = dev_get_drvdata(dev);
222         unsigned int tmp;
223
224         spin_lock_irq(&rtc->lock);
225
226         tmp = readb(rtc->regbase + RCR2);
227
228         if (enable) {
229                 rtc->periodic_freq |= PF_KOU;
230                 tmp &= ~RCR2_PEF;       /* Clear PES bit */
231                 tmp |= (rtc->periodic_freq & ~PF_HP);   /* Set PES2-0 */
232         } else {
233                 rtc->periodic_freq &= ~PF_KOU;
234                 tmp &= ~(RCR2_PESMASK | RCR2_PEF);
235         }
236
237         writeb(tmp, rtc->regbase + RCR2);
238
239         spin_unlock_irq(&rtc->lock);
240
241         return 0;
242 }
243
244 static int sh_rtc_irq_set_freq(struct device *dev, int freq)
245 {
246         struct sh_rtc *rtc = dev_get_drvdata(dev);
247         int tmp, ret = 0;
248
249         spin_lock_irq(&rtc->lock);
250         tmp = rtc->periodic_freq & PF_MASK;
251
252         switch (freq) {
253         case 0:
254                 rtc->periodic_freq = 0x00;
255                 break;
256         case 1:
257                 rtc->periodic_freq = 0x60;
258                 break;
259         case 2:
260                 rtc->periodic_freq = 0x50;
261                 break;
262         case 4:
263                 rtc->periodic_freq = 0x40;
264                 break;
265         case 8:
266                 rtc->periodic_freq = 0x30 | PF_HP;
267                 break;
268         case 16:
269                 rtc->periodic_freq = 0x30;
270                 break;
271         case 32:
272                 rtc->periodic_freq = 0x20 | PF_HP;
273                 break;
274         case 64:
275                 rtc->periodic_freq = 0x20;
276                 break;
277         case 128:
278                 rtc->periodic_freq = 0x10 | PF_HP;
279                 break;
280         case 256:
281                 rtc->periodic_freq = 0x10;
282                 break;
283         default:
284                 ret = -ENOTSUPP;
285         }
286
287         if (ret == 0)
288                 rtc->periodic_freq |= tmp;
289
290         spin_unlock_irq(&rtc->lock);
291         return ret;
292 }
293
294 static inline void sh_rtc_setaie(struct device *dev, unsigned int enable)
295 {
296         struct sh_rtc *rtc = dev_get_drvdata(dev);
297         unsigned int tmp;
298
299         spin_lock_irq(&rtc->lock);
300
301         tmp = readb(rtc->regbase + RCR1);
302
303         if (enable)
304                 tmp |= RCR1_AIE;
305         else
306                 tmp &= ~RCR1_AIE;
307
308         writeb(tmp, rtc->regbase + RCR1);
309
310         spin_unlock_irq(&rtc->lock);
311 }
312
313 static int sh_rtc_proc(struct device *dev, struct seq_file *seq)
314 {
315         struct sh_rtc *rtc = dev_get_drvdata(dev);
316         unsigned int tmp;
317
318         tmp = readb(rtc->regbase + RCR1);
319         seq_printf(seq, "carry_IRQ\t: %s\n", (tmp & RCR1_CIE) ? "yes" : "no");
320
321         tmp = readb(rtc->regbase + RCR2);
322         seq_printf(seq, "periodic_IRQ\t: %s\n",
323                    (tmp & RCR2_PESMASK) ? "yes" : "no");
324
325         return 0;
326 }
327
328 static inline void sh_rtc_setcie(struct device *dev, unsigned int enable)
329 {
330         struct sh_rtc *rtc = dev_get_drvdata(dev);
331         unsigned int tmp;
332
333         spin_lock_irq(&rtc->lock);
334
335         tmp = readb(rtc->regbase + RCR1);
336
337         if (!enable)
338                 tmp &= ~RCR1_CIE;
339         else
340                 tmp |= RCR1_CIE;
341
342         writeb(tmp, rtc->regbase + RCR1);
343
344         spin_unlock_irq(&rtc->lock);
345 }
346
347 static int sh_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
348 {
349         sh_rtc_setaie(dev, enabled);
350         return 0;
351 }
352
353 static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm)
354 {
355         struct platform_device *pdev = to_platform_device(dev);
356         struct sh_rtc *rtc = platform_get_drvdata(pdev);
357         unsigned int sec128, sec2, yr, yr100, cf_bit;
358
359         do {
360                 unsigned int tmp;
361
362                 spin_lock_irq(&rtc->lock);
363
364                 tmp = readb(rtc->regbase + RCR1);
365                 tmp &= ~RCR1_CF; /* Clear CF-bit */
366                 tmp |= RCR1_CIE;
367                 writeb(tmp, rtc->regbase + RCR1);
368
369                 sec128 = readb(rtc->regbase + R64CNT);
370
371                 tm->tm_sec      = bcd2bin(readb(rtc->regbase + RSECCNT));
372                 tm->tm_min      = bcd2bin(readb(rtc->regbase + RMINCNT));
373                 tm->tm_hour     = bcd2bin(readb(rtc->regbase + RHRCNT));
374                 tm->tm_wday     = bcd2bin(readb(rtc->regbase + RWKCNT));
375                 tm->tm_mday     = bcd2bin(readb(rtc->regbase + RDAYCNT));
376                 tm->tm_mon      = bcd2bin(readb(rtc->regbase + RMONCNT)) - 1;
377
378                 if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
379                         yr  = readw(rtc->regbase + RYRCNT);
380                         yr100 = bcd2bin(yr >> 8);
381                         yr &= 0xff;
382                 } else {
383                         yr  = readb(rtc->regbase + RYRCNT);
384                         yr100 = bcd2bin((yr == 0x99) ? 0x19 : 0x20);
385                 }
386
387                 tm->tm_year = (yr100 * 100 + bcd2bin(yr)) - 1900;
388
389                 sec2 = readb(rtc->regbase + R64CNT);
390                 cf_bit = readb(rtc->regbase + RCR1) & RCR1_CF;
391
392                 spin_unlock_irq(&rtc->lock);
393         } while (cf_bit != 0 || ((sec128 ^ sec2) & RTC_BIT_INVERTED) != 0);
394
395 #if RTC_BIT_INVERTED != 0
396         if ((sec128 & RTC_BIT_INVERTED))
397                 tm->tm_sec--;
398 #endif
399
400         /* only keep the carry interrupt enabled if UIE is on */
401         if (!(rtc->periodic_freq & PF_OXS))
402                 sh_rtc_setcie(dev, 0);
403
404         dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
405                 "mday=%d, mon=%d, year=%d, wday=%d\n",
406                 __func__,
407                 tm->tm_sec, tm->tm_min, tm->tm_hour,
408                 tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
409
410         return rtc_valid_tm(tm);
411 }
412
413 static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm)
414 {
415         struct platform_device *pdev = to_platform_device(dev);
416         struct sh_rtc *rtc = platform_get_drvdata(pdev);
417         unsigned int tmp;
418         int year;
419
420         spin_lock_irq(&rtc->lock);
421
422         /* Reset pre-scaler & stop RTC */
423         tmp = readb(rtc->regbase + RCR2);
424         tmp |= RCR2_RESET;
425         tmp &= ~RCR2_START;
426         writeb(tmp, rtc->regbase + RCR2);
427
428         writeb(bin2bcd(tm->tm_sec),  rtc->regbase + RSECCNT);
429         writeb(bin2bcd(tm->tm_min),  rtc->regbase + RMINCNT);
430         writeb(bin2bcd(tm->tm_hour), rtc->regbase + RHRCNT);
431         writeb(bin2bcd(tm->tm_wday), rtc->regbase + RWKCNT);
432         writeb(bin2bcd(tm->tm_mday), rtc->regbase + RDAYCNT);
433         writeb(bin2bcd(tm->tm_mon + 1), rtc->regbase + RMONCNT);
434
435         if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
436                 year = (bin2bcd((tm->tm_year + 1900) / 100) << 8) |
437                         bin2bcd(tm->tm_year % 100);
438                 writew(year, rtc->regbase + RYRCNT);
439         } else {
440                 year = tm->tm_year % 100;
441                 writeb(bin2bcd(year), rtc->regbase + RYRCNT);
442         }
443
444         /* Start RTC */
445         tmp = readb(rtc->regbase + RCR2);
446         tmp &= ~RCR2_RESET;
447         tmp |= RCR2_RTCEN | RCR2_START;
448         writeb(tmp, rtc->regbase + RCR2);
449
450         spin_unlock_irq(&rtc->lock);
451
452         return 0;
453 }
454
455 static inline int sh_rtc_read_alarm_value(struct sh_rtc *rtc, int reg_off)
456 {
457         unsigned int byte;
458         int value = 0xff;       /* return 0xff for ignored values */
459
460         byte = readb(rtc->regbase + reg_off);
461         if (byte & AR_ENB) {
462                 byte &= ~AR_ENB;        /* strip the enable bit */
463                 value = bcd2bin(byte);
464         }
465
466         return value;
467 }
468
469 static int sh_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
470 {
471         struct platform_device *pdev = to_platform_device(dev);
472         struct sh_rtc *rtc = platform_get_drvdata(pdev);
473         struct rtc_time *tm = &wkalrm->time;
474
475         spin_lock_irq(&rtc->lock);
476
477         tm->tm_sec      = sh_rtc_read_alarm_value(rtc, RSECAR);
478         tm->tm_min      = sh_rtc_read_alarm_value(rtc, RMINAR);
479         tm->tm_hour     = sh_rtc_read_alarm_value(rtc, RHRAR);
480         tm->tm_wday     = sh_rtc_read_alarm_value(rtc, RWKAR);
481         tm->tm_mday     = sh_rtc_read_alarm_value(rtc, RDAYAR);
482         tm->tm_mon      = sh_rtc_read_alarm_value(rtc, RMONAR);
483         if (tm->tm_mon > 0)
484                 tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */
485         tm->tm_year     = 0xffff;
486
487         wkalrm->enabled = (readb(rtc->regbase + RCR1) & RCR1_AIE) ? 1 : 0;
488
489         spin_unlock_irq(&rtc->lock);
490
491         return 0;
492 }
493
494 static inline void sh_rtc_write_alarm_value(struct sh_rtc *rtc,
495                                             int value, int reg_off)
496 {
497         /* < 0 for a value that is ignored */
498         if (value < 0)
499                 writeb(0, rtc->regbase + reg_off);
500         else
501                 writeb(bin2bcd(value) | AR_ENB,  rtc->regbase + reg_off);
502 }
503
504 static int sh_rtc_check_alarm(struct rtc_time *tm)
505 {
506         /*
507          * The original rtc says anything > 0xc0 is "don't care" or "match
508          * all" - most users use 0xff but rtc-dev uses -1 for the same thing.
509          * The original rtc doesn't support years - some things use -1 and
510          * some 0xffff. We use -1 to make out tests easier.
511          */
512         if (tm->tm_year == 0xffff)
513                 tm->tm_year = -1;
514         if (tm->tm_mon >= 0xff)
515                 tm->tm_mon = -1;
516         if (tm->tm_mday >= 0xff)
517                 tm->tm_mday = -1;
518         if (tm->tm_wday >= 0xff)
519                 tm->tm_wday = -1;
520         if (tm->tm_hour >= 0xff)
521                 tm->tm_hour = -1;
522         if (tm->tm_min >= 0xff)
523                 tm->tm_min = -1;
524         if (tm->tm_sec >= 0xff)
525                 tm->tm_sec = -1;
526
527         if (tm->tm_year > 9999 ||
528                 tm->tm_mon >= 12 ||
529                 tm->tm_mday == 0 || tm->tm_mday >= 32 ||
530                 tm->tm_wday >= 7 ||
531                 tm->tm_hour >= 24 ||
532                 tm->tm_min >= 60 ||
533                 tm->tm_sec >= 60)
534                 return -EINVAL;
535
536         return 0;
537 }
538
539 static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
540 {
541         struct platform_device *pdev = to_platform_device(dev);
542         struct sh_rtc *rtc = platform_get_drvdata(pdev);
543         unsigned int rcr1;
544         struct rtc_time *tm = &wkalrm->time;
545         int mon, err;
546
547         err = sh_rtc_check_alarm(tm);
548         if (unlikely(err < 0))
549                 return err;
550
551         spin_lock_irq(&rtc->lock);
552
553         /* disable alarm interrupt and clear the alarm flag */
554         rcr1 = readb(rtc->regbase + RCR1);
555         rcr1 &= ~(RCR1_AF | RCR1_AIE);
556         writeb(rcr1, rtc->regbase + RCR1);
557
558         /* set alarm time */
559         sh_rtc_write_alarm_value(rtc, tm->tm_sec,  RSECAR);
560         sh_rtc_write_alarm_value(rtc, tm->tm_min,  RMINAR);
561         sh_rtc_write_alarm_value(rtc, tm->tm_hour, RHRAR);
562         sh_rtc_write_alarm_value(rtc, tm->tm_wday, RWKAR);
563         sh_rtc_write_alarm_value(rtc, tm->tm_mday, RDAYAR);
564         mon = tm->tm_mon;
565         if (mon >= 0)
566                 mon += 1;
567         sh_rtc_write_alarm_value(rtc, mon, RMONAR);
568
569         if (wkalrm->enabled) {
570                 rcr1 |= RCR1_AIE;
571                 writeb(rcr1, rtc->regbase + RCR1);
572         }
573
574         spin_unlock_irq(&rtc->lock);
575
576         return 0;
577 }
578
579 static struct rtc_class_ops sh_rtc_ops = {
580         .read_time      = sh_rtc_read_time,
581         .set_time       = sh_rtc_set_time,
582         .read_alarm     = sh_rtc_read_alarm,
583         .set_alarm      = sh_rtc_set_alarm,
584         .proc           = sh_rtc_proc,
585         .alarm_irq_enable = sh_rtc_alarm_irq_enable,
586 };
587
588 static int __init sh_rtc_probe(struct platform_device *pdev)
589 {
590         struct sh_rtc *rtc;
591         struct resource *res;
592         struct rtc_time r;
593         char clk_name[6];
594         int clk_id, ret;
595
596         rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
597         if (unlikely(!rtc))
598                 return -ENOMEM;
599
600         spin_lock_init(&rtc->lock);
601
602         /* get periodic/carry/alarm irqs */
603         ret = platform_get_irq(pdev, 0);
604         if (unlikely(ret <= 0)) {
605                 dev_err(&pdev->dev, "No IRQ resource\n");
606                 return -ENOENT;
607         }
608
609         rtc->periodic_irq = ret;
610         rtc->carry_irq = platform_get_irq(pdev, 1);
611         rtc->alarm_irq = platform_get_irq(pdev, 2);
612
613         res = platform_get_resource(pdev, IORESOURCE_IO, 0);
614         if (unlikely(res == NULL)) {
615                 dev_err(&pdev->dev, "No IO resource\n");
616                 return -ENOENT;
617         }
618
619         rtc->regsize = resource_size(res);
620
621         rtc->res = devm_request_mem_region(&pdev->dev, res->start,
622                                         rtc->regsize, pdev->name);
623         if (unlikely(!rtc->res))
624                 return -EBUSY;
625
626         rtc->regbase = devm_ioremap_nocache(&pdev->dev, rtc->res->start,
627                                         rtc->regsize);
628         if (unlikely(!rtc->regbase))
629                 return -EINVAL;
630
631         clk_id = pdev->id;
632         /* With a single device, the clock id is still "rtc0" */
633         if (clk_id < 0)
634                 clk_id = 0;
635
636         snprintf(clk_name, sizeof(clk_name), "rtc%d", clk_id);
637
638         rtc->clk = devm_clk_get(&pdev->dev, clk_name);
639         if (IS_ERR(rtc->clk)) {
640                 /*
641                  * No error handling for rtc->clk intentionally, not all
642                  * platforms will have a unique clock for the RTC, and
643                  * the clk API can handle the struct clk pointer being
644                  * NULL.
645                  */
646                 rtc->clk = NULL;
647         }
648
649         clk_enable(rtc->clk);
650
651         rtc->capabilities = RTC_DEF_CAPABILITIES;
652         if (dev_get_platdata(&pdev->dev)) {
653                 struct sh_rtc_platform_info *pinfo =
654                         dev_get_platdata(&pdev->dev);
655
656                 /*
657                  * Some CPUs have special capabilities in addition to the
658                  * default set. Add those in here.
659                  */
660                 rtc->capabilities |= pinfo->capabilities;
661         }
662
663         if (rtc->carry_irq <= 0) {
664                 /* register shared periodic/carry/alarm irq */
665                 ret = devm_request_irq(&pdev->dev, rtc->periodic_irq,
666                                 sh_rtc_shared, 0, "sh-rtc", rtc);
667                 if (unlikely(ret)) {
668                         dev_err(&pdev->dev,
669                                 "request IRQ failed with %d, IRQ %d\n", ret,
670                                 rtc->periodic_irq);
671                         goto err_unmap;
672                 }
673         } else {
674                 /* register periodic/carry/alarm irqs */
675                 ret = devm_request_irq(&pdev->dev, rtc->periodic_irq,
676                                 sh_rtc_periodic, 0, "sh-rtc period", rtc);
677                 if (unlikely(ret)) {
678                         dev_err(&pdev->dev,
679                                 "request period IRQ failed with %d, IRQ %d\n",
680                                 ret, rtc->periodic_irq);
681                         goto err_unmap;
682                 }
683
684                 ret = devm_request_irq(&pdev->dev, rtc->carry_irq,
685                                 sh_rtc_interrupt, 0, "sh-rtc carry", rtc);
686                 if (unlikely(ret)) {
687                         dev_err(&pdev->dev,
688                                 "request carry IRQ failed with %d, IRQ %d\n",
689                                 ret, rtc->carry_irq);
690                         goto err_unmap;
691                 }
692
693                 ret = devm_request_irq(&pdev->dev, rtc->alarm_irq,
694                                 sh_rtc_alarm, 0, "sh-rtc alarm", rtc);
695                 if (unlikely(ret)) {
696                         dev_err(&pdev->dev,
697                                 "request alarm IRQ failed with %d, IRQ %d\n",
698                                 ret, rtc->alarm_irq);
699                         goto err_unmap;
700                 }
701         }
702
703         platform_set_drvdata(pdev, rtc);
704
705         /* everything disabled by default */
706         sh_rtc_irq_set_freq(&pdev->dev, 0);
707         sh_rtc_irq_set_state(&pdev->dev, 0);
708         sh_rtc_setaie(&pdev->dev, 0);
709         sh_rtc_setcie(&pdev->dev, 0);
710
711         rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "sh",
712                                            &sh_rtc_ops, THIS_MODULE);
713         if (IS_ERR(rtc->rtc_dev)) {
714                 ret = PTR_ERR(rtc->rtc_dev);
715                 goto err_unmap;
716         }
717
718         rtc->rtc_dev->max_user_freq = 256;
719
720         /* reset rtc to epoch 0 if time is invalid */
721         if (rtc_read_time(rtc->rtc_dev, &r) < 0) {
722                 rtc_time_to_tm(0, &r);
723                 rtc_set_time(rtc->rtc_dev, &r);
724         }
725
726         device_init_wakeup(&pdev->dev, 1);
727         return 0;
728
729 err_unmap:
730         clk_disable(rtc->clk);
731
732         return ret;
733 }
734
735 static int __exit sh_rtc_remove(struct platform_device *pdev)
736 {
737         struct sh_rtc *rtc = platform_get_drvdata(pdev);
738
739         sh_rtc_irq_set_state(&pdev->dev, 0);
740
741         sh_rtc_setaie(&pdev->dev, 0);
742         sh_rtc_setcie(&pdev->dev, 0);
743
744         clk_disable(rtc->clk);
745
746         return 0;
747 }
748
749 static void sh_rtc_set_irq_wake(struct device *dev, int enabled)
750 {
751         struct platform_device *pdev = to_platform_device(dev);
752         struct sh_rtc *rtc = platform_get_drvdata(pdev);
753
754         irq_set_irq_wake(rtc->periodic_irq, enabled);
755
756         if (rtc->carry_irq > 0) {
757                 irq_set_irq_wake(rtc->carry_irq, enabled);
758                 irq_set_irq_wake(rtc->alarm_irq, enabled);
759         }
760 }
761
762 #ifdef CONFIG_PM_SLEEP
763 static int sh_rtc_suspend(struct device *dev)
764 {
765         if (device_may_wakeup(dev))
766                 sh_rtc_set_irq_wake(dev, 1);
767
768         return 0;
769 }
770
771 static int sh_rtc_resume(struct device *dev)
772 {
773         if (device_may_wakeup(dev))
774                 sh_rtc_set_irq_wake(dev, 0);
775
776         return 0;
777 }
778 #endif
779
780 static SIMPLE_DEV_PM_OPS(sh_rtc_pm_ops, sh_rtc_suspend, sh_rtc_resume);
781
782 static struct platform_driver sh_rtc_platform_driver = {
783         .driver         = {
784                 .name   = DRV_NAME,
785                 .owner  = THIS_MODULE,
786                 .pm     = &sh_rtc_pm_ops,
787         },
788         .remove         = __exit_p(sh_rtc_remove),
789 };
790
791 module_platform_driver_probe(sh_rtc_platform_driver, sh_rtc_probe);
792
793 MODULE_DESCRIPTION("SuperH on-chip RTC driver");
794 MODULE_VERSION(DRV_VERSION);
795 MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, "
796               "Jamie Lenehan <lenehan@twibble.org>, "
797               "Angelo Castello <angelo.castello@st.com>");
798 MODULE_LICENSE("GPL");
799 MODULE_ALIAS("platform:" DRV_NAME);