xref: /openbmc/qemu/hw/rtc/exynos4210_rtc.c (revision 8e3b0cbb)
1 /*
2  * Samsung exynos4210 Real Time Clock
3  *
4  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
5  *  Ogurtsov Oleg <o.ogurtsov@samsung.com>
6  *
7  *  This program is free software; you can redistribute it and/or modify it
8  *  under the terms of the GNU General Public License as published by the
9  *  Free Software Foundation; either version 2 of the License, or
10  *  (at your option) any later version.
11  *
12  *  This program is distributed in the hope that it will be useful, but WITHOUT
13  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  *  FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15  *  for more details.
16  *
17  *  You should have received a copy of the GNU General Public License along
18  *  with this program; if not, see <http://www.gnu.org/licenses/>.
19  *
20  */
21 
22 /* Description:
23  * Register RTCCON:
24  *  CLKSEL Bit[1] not used
25  *  CLKOUTEN Bit[9] not used
26  */
27 
28 #include "qemu/osdep.h"
29 #include "qemu/log.h"
30 #include "qemu/module.h"
31 #include "hw/sysbus.h"
32 #include "migration/vmstate.h"
33 #include "qemu/timer.h"
34 #include "qemu/bcd.h"
35 #include "hw/ptimer.h"
36 
37 #include "hw/irq.h"
38 
39 #include "hw/arm/exynos4210.h"
40 #include "qom/object.h"
41 #include "sysemu/rtc.h"
42 
43 #define DEBUG_RTC 0
44 
45 #if DEBUG_RTC
46 #define DPRINTF(fmt, ...) \
47         do { fprintf(stdout, "RTC: [%24s:%5d] " fmt, __func__, __LINE__, \
48                 ## __VA_ARGS__); } while (0)
49 #else
50 #define DPRINTF(fmt, ...) do {} while (0)
51 #endif
52 
53 #define     EXYNOS4210_RTC_REG_MEM_SIZE     0x0100
54 
55 #define     INTP            0x0030
56 #define     RTCCON          0x0040
57 #define     TICCNT          0x0044
58 #define     RTCALM          0x0050
59 #define     ALMSEC          0x0054
60 #define     ALMMIN          0x0058
61 #define     ALMHOUR         0x005C
62 #define     ALMDAY          0x0060
63 #define     ALMMON          0x0064
64 #define     ALMYEAR         0x0068
65 #define     BCDSEC          0x0070
66 #define     BCDMIN          0x0074
67 #define     BCDHOUR         0x0078
68 #define     BCDDAY          0x007C
69 #define     BCDDAYWEEK      0x0080
70 #define     BCDMON          0x0084
71 #define     BCDYEAR         0x0088
72 #define     CURTICNT        0x0090
73 
74 #define     TICK_TIMER_ENABLE   0x0100
75 #define     TICNT_THRESHOLD     2
76 
77 
78 #define     RTC_ENABLE          0x0001
79 
80 #define     INTP_TICK_ENABLE    0x0001
81 #define     INTP_ALM_ENABLE     0x0002
82 
83 #define     ALARM_INT_ENABLE    0x0040
84 
85 #define     RTC_BASE_FREQ       32768
86 
87 #define TYPE_EXYNOS4210_RTC "exynos4210.rtc"
88 OBJECT_DECLARE_SIMPLE_TYPE(Exynos4210RTCState, EXYNOS4210_RTC)
89 
90 struct Exynos4210RTCState {
91     SysBusDevice parent_obj;
92 
93     MemoryRegion iomem;
94 
95     /* registers */
96     uint32_t    reg_intp;
97     uint32_t    reg_rtccon;
98     uint32_t    reg_ticcnt;
99     uint32_t    reg_rtcalm;
100     uint32_t    reg_almsec;
101     uint32_t    reg_almmin;
102     uint32_t    reg_almhour;
103     uint32_t    reg_almday;
104     uint32_t    reg_almmon;
105     uint32_t    reg_almyear;
106     uint32_t    reg_curticcnt;
107 
108     ptimer_state    *ptimer;        /* tick timer */
109     ptimer_state    *ptimer_1Hz;    /* clock timer */
110     uint32_t        freq;
111 
112     qemu_irq        tick_irq;   /* Time Tick Generator irq */
113     qemu_irq        alm_irq;    /* alarm irq */
114 
115     struct tm   current_tm;     /* current time */
116 };
117 
118 #define TICCKSEL(value) ((value & (0x0F << 4)) >> 4)
119 
120 /*** VMState ***/
121 static const VMStateDescription vmstate_exynos4210_rtc_state = {
122     .name = "exynos4210.rtc",
123     .version_id = 1,
124     .minimum_version_id = 1,
125     .fields = (VMStateField[]) {
126         VMSTATE_UINT32(reg_intp, Exynos4210RTCState),
127         VMSTATE_UINT32(reg_rtccon, Exynos4210RTCState),
128         VMSTATE_UINT32(reg_ticcnt, Exynos4210RTCState),
129         VMSTATE_UINT32(reg_rtcalm, Exynos4210RTCState),
130         VMSTATE_UINT32(reg_almsec, Exynos4210RTCState),
131         VMSTATE_UINT32(reg_almmin, Exynos4210RTCState),
132         VMSTATE_UINT32(reg_almhour, Exynos4210RTCState),
133         VMSTATE_UINT32(reg_almday, Exynos4210RTCState),
134         VMSTATE_UINT32(reg_almmon, Exynos4210RTCState),
135         VMSTATE_UINT32(reg_almyear, Exynos4210RTCState),
136         VMSTATE_UINT32(reg_curticcnt, Exynos4210RTCState),
137         VMSTATE_PTIMER(ptimer, Exynos4210RTCState),
138         VMSTATE_PTIMER(ptimer_1Hz, Exynos4210RTCState),
139         VMSTATE_UINT32(freq, Exynos4210RTCState),
140         VMSTATE_INT32(current_tm.tm_sec, Exynos4210RTCState),
141         VMSTATE_INT32(current_tm.tm_min, Exynos4210RTCState),
142         VMSTATE_INT32(current_tm.tm_hour, Exynos4210RTCState),
143         VMSTATE_INT32(current_tm.tm_wday, Exynos4210RTCState),
144         VMSTATE_INT32(current_tm.tm_mday, Exynos4210RTCState),
145         VMSTATE_INT32(current_tm.tm_mon, Exynos4210RTCState),
146         VMSTATE_INT32(current_tm.tm_year, Exynos4210RTCState),
147         VMSTATE_END_OF_LIST()
148     }
149 };
150 
151 #define BCD3DIGITS(x) \
152     ((uint32_t)to_bcd((uint8_t)(x % 100)) + \
153     ((uint32_t)to_bcd((uint8_t)((x % 1000) / 100)) << 8))
154 
155 static void check_alarm_raise(Exynos4210RTCState *s)
156 {
157     unsigned int alarm_raise = 0;
158     struct tm stm = s->current_tm;
159 
160     if ((s->reg_rtcalm & 0x01) &&
161         (to_bcd((uint8_t)stm.tm_sec) == (uint8_t)s->reg_almsec)) {
162         alarm_raise = 1;
163     }
164     if ((s->reg_rtcalm & 0x02) &&
165         (to_bcd((uint8_t)stm.tm_min) == (uint8_t)s->reg_almmin)) {
166         alarm_raise = 1;
167     }
168     if ((s->reg_rtcalm & 0x04) &&
169         (to_bcd((uint8_t)stm.tm_hour) == (uint8_t)s->reg_almhour)) {
170         alarm_raise = 1;
171     }
172     if ((s->reg_rtcalm & 0x08) &&
173         (to_bcd((uint8_t)stm.tm_mday) == (uint8_t)s->reg_almday)) {
174         alarm_raise = 1;
175     }
176     if ((s->reg_rtcalm & 0x10) &&
177          (to_bcd((uint8_t)stm.tm_mon) == (uint8_t)s->reg_almmon)) {
178         alarm_raise = 1;
179     }
180     if ((s->reg_rtcalm & 0x20) &&
181         (BCD3DIGITS(stm.tm_year) == s->reg_almyear)) {
182         alarm_raise = 1;
183     }
184 
185     if (alarm_raise) {
186         DPRINTF("ALARM IRQ\n");
187         /* set irq status */
188         s->reg_intp |= INTP_ALM_ENABLE;
189         qemu_irq_raise(s->alm_irq);
190     }
191 }
192 
193 /*
194  * RTC update frequency
195  * Parameters:
196  *     reg_value - current RTCCON register or his new value
197  * Must be called within a ptimer_transaction_begin/commit block for s->ptimer.
198  */
199 static void exynos4210_rtc_update_freq(Exynos4210RTCState *s,
200                                        uint32_t reg_value)
201 {
202     uint32_t freq;
203 
204     freq = s->freq;
205     /* set frequncy for time generator */
206     s->freq = RTC_BASE_FREQ / (1 << TICCKSEL(reg_value));
207 
208     if (freq != s->freq) {
209         ptimer_set_freq(s->ptimer, s->freq);
210         DPRINTF("freq=%dHz\n", s->freq);
211     }
212 }
213 
214 /* month is between 0 and 11. */
215 static int get_days_in_month(int month, int year)
216 {
217     static const int days_tab[12] = {
218         31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
219     };
220     int d;
221     if ((unsigned)month >= 12) {
222         return 31;
223     }
224     d = days_tab[month];
225     if (month == 1) {
226         if ((year % 4) == 0 && ((year % 100) != 0 || (year % 400) == 0)) {
227             d++;
228         }
229     }
230     return d;
231 }
232 
233 /* update 'tm' to the next second */
234 static void rtc_next_second(struct tm *tm)
235 {
236     int days_in_month;
237 
238     tm->tm_sec++;
239     if ((unsigned)tm->tm_sec >= 60) {
240         tm->tm_sec = 0;
241         tm->tm_min++;
242         if ((unsigned)tm->tm_min >= 60) {
243             tm->tm_min = 0;
244             tm->tm_hour++;
245             if ((unsigned)tm->tm_hour >= 24) {
246                 tm->tm_hour = 0;
247                 /* next day */
248                 tm->tm_wday++;
249                 if ((unsigned)tm->tm_wday >= 7) {
250                     tm->tm_wday = 0;
251                 }
252                 days_in_month = get_days_in_month(tm->tm_mon,
253                                                   tm->tm_year + 1900);
254                 tm->tm_mday++;
255                 if (tm->tm_mday < 1) {
256                     tm->tm_mday = 1;
257                 } else if (tm->tm_mday > days_in_month) {
258                     tm->tm_mday = 1;
259                     tm->tm_mon++;
260                     if (tm->tm_mon >= 12) {
261                         tm->tm_mon = 0;
262                         tm->tm_year++;
263                     }
264                 }
265             }
266         }
267     }
268 }
269 
270 /*
271  * tick handler
272  */
273 static void exynos4210_rtc_tick(void *opaque)
274 {
275     Exynos4210RTCState *s = (Exynos4210RTCState *)opaque;
276 
277     DPRINTF("TICK IRQ\n");
278     /* set irq status */
279     s->reg_intp |= INTP_TICK_ENABLE;
280     /* raise IRQ */
281     qemu_irq_raise(s->tick_irq);
282 
283     /* restart timer */
284     ptimer_set_count(s->ptimer, s->reg_ticcnt);
285     ptimer_run(s->ptimer, 1);
286 }
287 
288 /*
289  * 1Hz clock handler
290  */
291 static void exynos4210_rtc_1Hz_tick(void *opaque)
292 {
293     Exynos4210RTCState *s = (Exynos4210RTCState *)opaque;
294 
295     rtc_next_second(&s->current_tm);
296     /* DPRINTF("1Hz tick\n"); */
297 
298     /* raise IRQ */
299     if (s->reg_rtcalm & ALARM_INT_ENABLE) {
300         check_alarm_raise(s);
301     }
302 
303     ptimer_set_count(s->ptimer_1Hz, RTC_BASE_FREQ);
304     ptimer_run(s->ptimer_1Hz, 1);
305 }
306 
307 /*
308  * RTC Read
309  */
310 static uint64_t exynos4210_rtc_read(void *opaque, hwaddr offset,
311         unsigned size)
312 {
313     uint32_t value = 0;
314     Exynos4210RTCState *s = (Exynos4210RTCState *)opaque;
315 
316     switch (offset) {
317     case INTP:
318         value = s->reg_intp;
319         break;
320     case RTCCON:
321         value = s->reg_rtccon;
322         break;
323     case TICCNT:
324         value = s->reg_ticcnt;
325         break;
326     case RTCALM:
327         value = s->reg_rtcalm;
328         break;
329     case ALMSEC:
330         value = s->reg_almsec;
331         break;
332     case ALMMIN:
333         value = s->reg_almmin;
334         break;
335     case ALMHOUR:
336         value = s->reg_almhour;
337         break;
338     case ALMDAY:
339         value = s->reg_almday;
340         break;
341     case ALMMON:
342         value = s->reg_almmon;
343         break;
344     case ALMYEAR:
345         value = s->reg_almyear;
346         break;
347 
348     case BCDSEC:
349         value = (uint32_t)to_bcd((uint8_t)s->current_tm.tm_sec);
350         break;
351     case BCDMIN:
352         value = (uint32_t)to_bcd((uint8_t)s->current_tm.tm_min);
353         break;
354     case BCDHOUR:
355         value = (uint32_t)to_bcd((uint8_t)s->current_tm.tm_hour);
356         break;
357     case BCDDAYWEEK:
358         value = (uint32_t)to_bcd((uint8_t)s->current_tm.tm_wday);
359         break;
360     case BCDDAY:
361         value = (uint32_t)to_bcd((uint8_t)s->current_tm.tm_mday);
362         break;
363     case BCDMON:
364         value = (uint32_t)to_bcd((uint8_t)s->current_tm.tm_mon + 1);
365         break;
366     case BCDYEAR:
367         value = BCD3DIGITS(s->current_tm.tm_year);
368         break;
369 
370     case CURTICNT:
371         s->reg_curticcnt = ptimer_get_count(s->ptimer);
372         value = s->reg_curticcnt;
373         break;
374 
375     default:
376         qemu_log_mask(LOG_GUEST_ERROR,
377                       "exynos4210.rtc: bad read offset " TARGET_FMT_plx,
378                       offset);
379         break;
380     }
381     return value;
382 }
383 
384 /*
385  * RTC Write
386  */
387 static void exynos4210_rtc_write(void *opaque, hwaddr offset,
388         uint64_t value, unsigned size)
389 {
390     Exynos4210RTCState *s = (Exynos4210RTCState *)opaque;
391 
392     switch (offset) {
393     case INTP:
394         if (value & INTP_ALM_ENABLE) {
395             qemu_irq_lower(s->alm_irq);
396             s->reg_intp &= (~INTP_ALM_ENABLE);
397         }
398         if (value & INTP_TICK_ENABLE) {
399             qemu_irq_lower(s->tick_irq);
400             s->reg_intp &= (~INTP_TICK_ENABLE);
401         }
402         break;
403     case RTCCON:
404         ptimer_transaction_begin(s->ptimer_1Hz);
405         ptimer_transaction_begin(s->ptimer);
406         if (value & RTC_ENABLE) {
407             exynos4210_rtc_update_freq(s, value);
408         }
409         if ((value & RTC_ENABLE) > (s->reg_rtccon & RTC_ENABLE)) {
410             /* clock timer */
411             ptimer_set_count(s->ptimer_1Hz, RTC_BASE_FREQ);
412             ptimer_run(s->ptimer_1Hz, 1);
413             DPRINTF("run clock timer\n");
414         }
415         if ((value & RTC_ENABLE) < (s->reg_rtccon & RTC_ENABLE)) {
416             /* tick timer */
417             ptimer_stop(s->ptimer);
418             /* clock timer */
419             ptimer_stop(s->ptimer_1Hz);
420             DPRINTF("stop all timers\n");
421         }
422         if (value & RTC_ENABLE) {
423             if ((value & TICK_TIMER_ENABLE) >
424                 (s->reg_rtccon & TICK_TIMER_ENABLE) &&
425                 (s->reg_ticcnt)) {
426                 ptimer_set_count(s->ptimer, s->reg_ticcnt);
427                 ptimer_run(s->ptimer, 1);
428                 DPRINTF("run tick timer\n");
429             }
430             if ((value & TICK_TIMER_ENABLE) <
431                 (s->reg_rtccon & TICK_TIMER_ENABLE)) {
432                 ptimer_stop(s->ptimer);
433             }
434         }
435         ptimer_transaction_commit(s->ptimer_1Hz);
436         ptimer_transaction_commit(s->ptimer);
437         s->reg_rtccon = value;
438         break;
439     case TICCNT:
440         if (value > TICNT_THRESHOLD) {
441             s->reg_ticcnt = value;
442         } else {
443             qemu_log_mask(LOG_GUEST_ERROR,
444                           "exynos4210.rtc: bad TICNT value %u",
445                           (uint32_t)value);
446         }
447         break;
448 
449     case RTCALM:
450         s->reg_rtcalm = value;
451         break;
452     case ALMSEC:
453         s->reg_almsec = (value & 0x7f);
454         break;
455     case ALMMIN:
456         s->reg_almmin = (value & 0x7f);
457         break;
458     case ALMHOUR:
459         s->reg_almhour = (value & 0x3f);
460         break;
461     case ALMDAY:
462         s->reg_almday = (value & 0x3f);
463         break;
464     case ALMMON:
465         s->reg_almmon = (value & 0x1f);
466         break;
467     case ALMYEAR:
468         s->reg_almyear = (value & 0x0fff);
469         break;
470 
471     case BCDSEC:
472         if (s->reg_rtccon & RTC_ENABLE) {
473             s->current_tm.tm_sec = (int)from_bcd((uint8_t)value);
474         }
475         break;
476     case BCDMIN:
477         if (s->reg_rtccon & RTC_ENABLE) {
478             s->current_tm.tm_min = (int)from_bcd((uint8_t)value);
479         }
480         break;
481     case BCDHOUR:
482         if (s->reg_rtccon & RTC_ENABLE) {
483             s->current_tm.tm_hour = (int)from_bcd((uint8_t)value);
484         }
485         break;
486     case BCDDAYWEEK:
487         if (s->reg_rtccon & RTC_ENABLE) {
488             s->current_tm.tm_wday = (int)from_bcd((uint8_t)value);
489         }
490         break;
491     case BCDDAY:
492         if (s->reg_rtccon & RTC_ENABLE) {
493             s->current_tm.tm_mday = (int)from_bcd((uint8_t)value);
494         }
495         break;
496     case BCDMON:
497         if (s->reg_rtccon & RTC_ENABLE) {
498             s->current_tm.tm_mon = (int)from_bcd((uint8_t)value) - 1;
499         }
500         break;
501     case BCDYEAR:
502         if (s->reg_rtccon & RTC_ENABLE) {
503             /* 3 digits */
504             s->current_tm.tm_year = (int)from_bcd((uint8_t)value) +
505                     (int)from_bcd((uint8_t)((value >> 8) & 0x0f)) * 100;
506         }
507         break;
508 
509     default:
510         qemu_log_mask(LOG_GUEST_ERROR,
511                       "exynos4210.rtc: bad write offset " TARGET_FMT_plx,
512                       offset);
513         break;
514 
515     }
516 }
517 
518 /*
519  * Set default values to timer fields and registers
520  */
521 static void exynos4210_rtc_reset(DeviceState *d)
522 {
523     Exynos4210RTCState *s = EXYNOS4210_RTC(d);
524 
525     qemu_get_timedate(&s->current_tm, 0);
526 
527     DPRINTF("Get time from host: %d-%d-%d %2d:%02d:%02d\n",
528             s->current_tm.tm_year, s->current_tm.tm_mon, s->current_tm.tm_mday,
529             s->current_tm.tm_hour, s->current_tm.tm_min, s->current_tm.tm_sec);
530 
531     s->reg_intp = 0;
532     s->reg_rtccon = 0;
533     s->reg_ticcnt = 0;
534     s->reg_rtcalm = 0;
535     s->reg_almsec = 0;
536     s->reg_almmin = 0;
537     s->reg_almhour = 0;
538     s->reg_almday = 0;
539     s->reg_almmon = 0;
540     s->reg_almyear = 0;
541 
542     s->reg_curticcnt = 0;
543 
544     ptimer_transaction_begin(s->ptimer);
545     exynos4210_rtc_update_freq(s, s->reg_rtccon);
546     ptimer_stop(s->ptimer);
547     ptimer_transaction_commit(s->ptimer);
548     ptimer_transaction_begin(s->ptimer_1Hz);
549     ptimer_stop(s->ptimer_1Hz);
550     ptimer_transaction_commit(s->ptimer_1Hz);
551 }
552 
553 static const MemoryRegionOps exynos4210_rtc_ops = {
554     .read = exynos4210_rtc_read,
555     .write = exynos4210_rtc_write,
556     .endianness = DEVICE_NATIVE_ENDIAN,
557 };
558 
559 /*
560  * RTC timer initialization
561  */
562 static void exynos4210_rtc_init(Object *obj)
563 {
564     Exynos4210RTCState *s = EXYNOS4210_RTC(obj);
565     SysBusDevice *dev = SYS_BUS_DEVICE(obj);
566 
567     s->ptimer = ptimer_init(exynos4210_rtc_tick, s, PTIMER_POLICY_DEFAULT);
568     ptimer_transaction_begin(s->ptimer);
569     ptimer_set_freq(s->ptimer, RTC_BASE_FREQ);
570     exynos4210_rtc_update_freq(s, 0);
571     ptimer_transaction_commit(s->ptimer);
572 
573     s->ptimer_1Hz = ptimer_init(exynos4210_rtc_1Hz_tick,
574                                 s, PTIMER_POLICY_DEFAULT);
575     ptimer_transaction_begin(s->ptimer_1Hz);
576     ptimer_set_freq(s->ptimer_1Hz, RTC_BASE_FREQ);
577     ptimer_transaction_commit(s->ptimer_1Hz);
578 
579     sysbus_init_irq(dev, &s->alm_irq);
580     sysbus_init_irq(dev, &s->tick_irq);
581 
582     memory_region_init_io(&s->iomem, obj, &exynos4210_rtc_ops, s,
583                           "exynos4210-rtc", EXYNOS4210_RTC_REG_MEM_SIZE);
584     sysbus_init_mmio(dev, &s->iomem);
585 }
586 
587 static void exynos4210_rtc_finalize(Object *obj)
588 {
589     Exynos4210RTCState *s = EXYNOS4210_RTC(obj);
590 
591     ptimer_free(s->ptimer);
592     ptimer_free(s->ptimer_1Hz);
593 }
594 
595 static void exynos4210_rtc_class_init(ObjectClass *klass, void *data)
596 {
597     DeviceClass *dc = DEVICE_CLASS(klass);
598 
599     dc->reset = exynos4210_rtc_reset;
600     dc->vmsd = &vmstate_exynos4210_rtc_state;
601 }
602 
603 static const TypeInfo exynos4210_rtc_info = {
604     .name          = TYPE_EXYNOS4210_RTC,
605     .parent        = TYPE_SYS_BUS_DEVICE,
606     .instance_size = sizeof(Exynos4210RTCState),
607     .instance_init = exynos4210_rtc_init,
608     .instance_finalize = exynos4210_rtc_finalize,
609     .class_init    = exynos4210_rtc_class_init,
610 };
611 
612 static void exynos4210_rtc_register_types(void)
613 {
614     type_register_static(&exynos4210_rtc_info);
615 }
616 
617 type_init(exynos4210_rtc_register_types)
618