xref: /openbmc/qemu/hw/rtc/exynos4210_rtc.c (revision c418f935)
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-common.h"
30 #include "qemu/log.h"
31 #include "qemu/module.h"
32 #include "hw/sysbus.h"
33 #include "migration/vmstate.h"
34 #include "qemu/timer.h"
35 #include "qemu/bcd.h"
36 #include "hw/ptimer.h"
37 
38 #include "hw/irq.h"
39 
40 #include "hw/arm/exynos4210.h"
41 #include "qom/object.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 typedef struct Exynos4210RTCState Exynos4210RTCState;
89 DECLARE_INSTANCE_CHECKER(Exynos4210RTCState, EXYNOS4210_RTC,
90                          TYPE_EXYNOS4210_RTC)
91 
92 struct Exynos4210RTCState {
93     SysBusDevice parent_obj;
94 
95     MemoryRegion iomem;
96 
97     /* registers */
98     uint32_t    reg_intp;
99     uint32_t    reg_rtccon;
100     uint32_t    reg_ticcnt;
101     uint32_t    reg_rtcalm;
102     uint32_t    reg_almsec;
103     uint32_t    reg_almmin;
104     uint32_t    reg_almhour;
105     uint32_t    reg_almday;
106     uint32_t    reg_almmon;
107     uint32_t    reg_almyear;
108     uint32_t    reg_curticcnt;
109 
110     ptimer_state    *ptimer;        /* tick timer */
111     ptimer_state    *ptimer_1Hz;    /* clock timer */
112     uint32_t        freq;
113 
114     qemu_irq        tick_irq;   /* Time Tick Generator irq */
115     qemu_irq        alm_irq;    /* alarm irq */
116 
117     struct tm   current_tm;     /* current time */
118 };
119 
120 #define TICCKSEL(value) ((value & (0x0F << 4)) >> 4)
121 
122 /*** VMState ***/
123 static const VMStateDescription vmstate_exynos4210_rtc_state = {
124     .name = "exynos4210.rtc",
125     .version_id = 1,
126     .minimum_version_id = 1,
127     .fields = (VMStateField[]) {
128         VMSTATE_UINT32(reg_intp, Exynos4210RTCState),
129         VMSTATE_UINT32(reg_rtccon, Exynos4210RTCState),
130         VMSTATE_UINT32(reg_ticcnt, Exynos4210RTCState),
131         VMSTATE_UINT32(reg_rtcalm, Exynos4210RTCState),
132         VMSTATE_UINT32(reg_almsec, Exynos4210RTCState),
133         VMSTATE_UINT32(reg_almmin, Exynos4210RTCState),
134         VMSTATE_UINT32(reg_almhour, Exynos4210RTCState),
135         VMSTATE_UINT32(reg_almday, Exynos4210RTCState),
136         VMSTATE_UINT32(reg_almmon, Exynos4210RTCState),
137         VMSTATE_UINT32(reg_almyear, Exynos4210RTCState),
138         VMSTATE_UINT32(reg_curticcnt, Exynos4210RTCState),
139         VMSTATE_PTIMER(ptimer, Exynos4210RTCState),
140         VMSTATE_PTIMER(ptimer_1Hz, Exynos4210RTCState),
141         VMSTATE_UINT32(freq, Exynos4210RTCState),
142         VMSTATE_INT32(current_tm.tm_sec, Exynos4210RTCState),
143         VMSTATE_INT32(current_tm.tm_min, Exynos4210RTCState),
144         VMSTATE_INT32(current_tm.tm_hour, Exynos4210RTCState),
145         VMSTATE_INT32(current_tm.tm_wday, Exynos4210RTCState),
146         VMSTATE_INT32(current_tm.tm_mday, Exynos4210RTCState),
147         VMSTATE_INT32(current_tm.tm_mon, Exynos4210RTCState),
148         VMSTATE_INT32(current_tm.tm_year, Exynos4210RTCState),
149         VMSTATE_END_OF_LIST()
150     }
151 };
152 
153 #define BCD3DIGITS(x) \
154     ((uint32_t)to_bcd((uint8_t)(x % 100)) + \
155     ((uint32_t)to_bcd((uint8_t)((x % 1000) / 100)) << 8))
156 
157 static void check_alarm_raise(Exynos4210RTCState *s)
158 {
159     unsigned int alarm_raise = 0;
160     struct tm stm = s->current_tm;
161 
162     if ((s->reg_rtcalm & 0x01) &&
163         (to_bcd((uint8_t)stm.tm_sec) == (uint8_t)s->reg_almsec)) {
164         alarm_raise = 1;
165     }
166     if ((s->reg_rtcalm & 0x02) &&
167         (to_bcd((uint8_t)stm.tm_min) == (uint8_t)s->reg_almmin)) {
168         alarm_raise = 1;
169     }
170     if ((s->reg_rtcalm & 0x04) &&
171         (to_bcd((uint8_t)stm.tm_hour) == (uint8_t)s->reg_almhour)) {
172         alarm_raise = 1;
173     }
174     if ((s->reg_rtcalm & 0x08) &&
175         (to_bcd((uint8_t)stm.tm_mday) == (uint8_t)s->reg_almday)) {
176         alarm_raise = 1;
177     }
178     if ((s->reg_rtcalm & 0x10) &&
179          (to_bcd((uint8_t)stm.tm_mon) == (uint8_t)s->reg_almmon)) {
180         alarm_raise = 1;
181     }
182     if ((s->reg_rtcalm & 0x20) &&
183         (BCD3DIGITS(stm.tm_year) == s->reg_almyear)) {
184         alarm_raise = 1;
185     }
186 
187     if (alarm_raise) {
188         DPRINTF("ALARM IRQ\n");
189         /* set irq status */
190         s->reg_intp |= INTP_ALM_ENABLE;
191         qemu_irq_raise(s->alm_irq);
192     }
193 }
194 
195 /*
196  * RTC update frequency
197  * Parameters:
198  *     reg_value - current RTCCON register or his new value
199  * Must be called within a ptimer_transaction_begin/commit block for s->ptimer.
200  */
201 static void exynos4210_rtc_update_freq(Exynos4210RTCState *s,
202                                        uint32_t reg_value)
203 {
204     uint32_t freq;
205 
206     freq = s->freq;
207     /* set frequncy for time generator */
208     s->freq = RTC_BASE_FREQ / (1 << TICCKSEL(reg_value));
209 
210     if (freq != s->freq) {
211         ptimer_set_freq(s->ptimer, s->freq);
212         DPRINTF("freq=%dHz\n", s->freq);
213     }
214 }
215 
216 /* month is between 0 and 11. */
217 static int get_days_in_month(int month, int year)
218 {
219     static const int days_tab[12] = {
220         31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
221     };
222     int d;
223     if ((unsigned)month >= 12) {
224         return 31;
225     }
226     d = days_tab[month];
227     if (month == 1) {
228         if ((year % 4) == 0 && ((year % 100) != 0 || (year % 400) == 0)) {
229             d++;
230         }
231     }
232     return d;
233 }
234 
235 /* update 'tm' to the next second */
236 static void rtc_next_second(struct tm *tm)
237 {
238     int days_in_month;
239 
240     tm->tm_sec++;
241     if ((unsigned)tm->tm_sec >= 60) {
242         tm->tm_sec = 0;
243         tm->tm_min++;
244         if ((unsigned)tm->tm_min >= 60) {
245             tm->tm_min = 0;
246             tm->tm_hour++;
247             if ((unsigned)tm->tm_hour >= 24) {
248                 tm->tm_hour = 0;
249                 /* next day */
250                 tm->tm_wday++;
251                 if ((unsigned)tm->tm_wday >= 7) {
252                     tm->tm_wday = 0;
253                 }
254                 days_in_month = get_days_in_month(tm->tm_mon,
255                                                   tm->tm_year + 1900);
256                 tm->tm_mday++;
257                 if (tm->tm_mday < 1) {
258                     tm->tm_mday = 1;
259                 } else if (tm->tm_mday > days_in_month) {
260                     tm->tm_mday = 1;
261                     tm->tm_mon++;
262                     if (tm->tm_mon >= 12) {
263                         tm->tm_mon = 0;
264                         tm->tm_year++;
265                     }
266                 }
267             }
268         }
269     }
270 }
271 
272 /*
273  * tick handler
274  */
275 static void exynos4210_rtc_tick(void *opaque)
276 {
277     Exynos4210RTCState *s = (Exynos4210RTCState *)opaque;
278 
279     DPRINTF("TICK IRQ\n");
280     /* set irq status */
281     s->reg_intp |= INTP_TICK_ENABLE;
282     /* raise IRQ */
283     qemu_irq_raise(s->tick_irq);
284 
285     /* restart timer */
286     ptimer_set_count(s->ptimer, s->reg_ticcnt);
287     ptimer_run(s->ptimer, 1);
288 }
289 
290 /*
291  * 1Hz clock handler
292  */
293 static void exynos4210_rtc_1Hz_tick(void *opaque)
294 {
295     Exynos4210RTCState *s = (Exynos4210RTCState *)opaque;
296 
297     rtc_next_second(&s->current_tm);
298     /* DPRINTF("1Hz tick\n"); */
299 
300     /* raise IRQ */
301     if (s->reg_rtcalm & ALARM_INT_ENABLE) {
302         check_alarm_raise(s);
303     }
304 
305     ptimer_set_count(s->ptimer_1Hz, RTC_BASE_FREQ);
306     ptimer_run(s->ptimer_1Hz, 1);
307 }
308 
309 /*
310  * RTC Read
311  */
312 static uint64_t exynos4210_rtc_read(void *opaque, hwaddr offset,
313         unsigned size)
314 {
315     uint32_t value = 0;
316     Exynos4210RTCState *s = (Exynos4210RTCState *)opaque;
317 
318     switch (offset) {
319     case INTP:
320         value = s->reg_intp;
321         break;
322     case RTCCON:
323         value = s->reg_rtccon;
324         break;
325     case TICCNT:
326         value = s->reg_ticcnt;
327         break;
328     case RTCALM:
329         value = s->reg_rtcalm;
330         break;
331     case ALMSEC:
332         value = s->reg_almsec;
333         break;
334     case ALMMIN:
335         value = s->reg_almmin;
336         break;
337     case ALMHOUR:
338         value = s->reg_almhour;
339         break;
340     case ALMDAY:
341         value = s->reg_almday;
342         break;
343     case ALMMON:
344         value = s->reg_almmon;
345         break;
346     case ALMYEAR:
347         value = s->reg_almyear;
348         break;
349 
350     case BCDSEC:
351         value = (uint32_t)to_bcd((uint8_t)s->current_tm.tm_sec);
352         break;
353     case BCDMIN:
354         value = (uint32_t)to_bcd((uint8_t)s->current_tm.tm_min);
355         break;
356     case BCDHOUR:
357         value = (uint32_t)to_bcd((uint8_t)s->current_tm.tm_hour);
358         break;
359     case BCDDAYWEEK:
360         value = (uint32_t)to_bcd((uint8_t)s->current_tm.tm_wday);
361         break;
362     case BCDDAY:
363         value = (uint32_t)to_bcd((uint8_t)s->current_tm.tm_mday);
364         break;
365     case BCDMON:
366         value = (uint32_t)to_bcd((uint8_t)s->current_tm.tm_mon + 1);
367         break;
368     case BCDYEAR:
369         value = BCD3DIGITS(s->current_tm.tm_year);
370         break;
371 
372     case CURTICNT:
373         s->reg_curticcnt = ptimer_get_count(s->ptimer);
374         value = s->reg_curticcnt;
375         break;
376 
377     default:
378         qemu_log_mask(LOG_GUEST_ERROR,
379                       "exynos4210.rtc: bad read offset " TARGET_FMT_plx,
380                       offset);
381         break;
382     }
383     return value;
384 }
385 
386 /*
387  * RTC Write
388  */
389 static void exynos4210_rtc_write(void *opaque, hwaddr offset,
390         uint64_t value, unsigned size)
391 {
392     Exynos4210RTCState *s = (Exynos4210RTCState *)opaque;
393 
394     switch (offset) {
395     case INTP:
396         if (value & INTP_ALM_ENABLE) {
397             qemu_irq_lower(s->alm_irq);
398             s->reg_intp &= (~INTP_ALM_ENABLE);
399         }
400         if (value & INTP_TICK_ENABLE) {
401             qemu_irq_lower(s->tick_irq);
402             s->reg_intp &= (~INTP_TICK_ENABLE);
403         }
404         break;
405     case RTCCON:
406         ptimer_transaction_begin(s->ptimer_1Hz);
407         ptimer_transaction_begin(s->ptimer);
408         if (value & RTC_ENABLE) {
409             exynos4210_rtc_update_freq(s, value);
410         }
411         if ((value & RTC_ENABLE) > (s->reg_rtccon & RTC_ENABLE)) {
412             /* clock timer */
413             ptimer_set_count(s->ptimer_1Hz, RTC_BASE_FREQ);
414             ptimer_run(s->ptimer_1Hz, 1);
415             DPRINTF("run clock timer\n");
416         }
417         if ((value & RTC_ENABLE) < (s->reg_rtccon & RTC_ENABLE)) {
418             /* tick timer */
419             ptimer_stop(s->ptimer);
420             /* clock timer */
421             ptimer_stop(s->ptimer_1Hz);
422             DPRINTF("stop all timers\n");
423         }
424         if (value & RTC_ENABLE) {
425             if ((value & TICK_TIMER_ENABLE) >
426                 (s->reg_rtccon & TICK_TIMER_ENABLE) &&
427                 (s->reg_ticcnt)) {
428                 ptimer_set_count(s->ptimer, s->reg_ticcnt);
429                 ptimer_run(s->ptimer, 1);
430                 DPRINTF("run tick timer\n");
431             }
432             if ((value & TICK_TIMER_ENABLE) <
433                 (s->reg_rtccon & TICK_TIMER_ENABLE)) {
434                 ptimer_stop(s->ptimer);
435             }
436         }
437         ptimer_transaction_commit(s->ptimer_1Hz);
438         ptimer_transaction_commit(s->ptimer);
439         s->reg_rtccon = value;
440         break;
441     case TICCNT:
442         if (value > TICNT_THRESHOLD) {
443             s->reg_ticcnt = value;
444         } else {
445             qemu_log_mask(LOG_GUEST_ERROR,
446                           "exynos4210.rtc: bad TICNT value %u",
447                           (uint32_t)value);
448         }
449         break;
450 
451     case RTCALM:
452         s->reg_rtcalm = value;
453         break;
454     case ALMSEC:
455         s->reg_almsec = (value & 0x7f);
456         break;
457     case ALMMIN:
458         s->reg_almmin = (value & 0x7f);
459         break;
460     case ALMHOUR:
461         s->reg_almhour = (value & 0x3f);
462         break;
463     case ALMDAY:
464         s->reg_almday = (value & 0x3f);
465         break;
466     case ALMMON:
467         s->reg_almmon = (value & 0x1f);
468         break;
469     case ALMYEAR:
470         s->reg_almyear = (value & 0x0fff);
471         break;
472 
473     case BCDSEC:
474         if (s->reg_rtccon & RTC_ENABLE) {
475             s->current_tm.tm_sec = (int)from_bcd((uint8_t)value);
476         }
477         break;
478     case BCDMIN:
479         if (s->reg_rtccon & RTC_ENABLE) {
480             s->current_tm.tm_min = (int)from_bcd((uint8_t)value);
481         }
482         break;
483     case BCDHOUR:
484         if (s->reg_rtccon & RTC_ENABLE) {
485             s->current_tm.tm_hour = (int)from_bcd((uint8_t)value);
486         }
487         break;
488     case BCDDAYWEEK:
489         if (s->reg_rtccon & RTC_ENABLE) {
490             s->current_tm.tm_wday = (int)from_bcd((uint8_t)value);
491         }
492         break;
493     case BCDDAY:
494         if (s->reg_rtccon & RTC_ENABLE) {
495             s->current_tm.tm_mday = (int)from_bcd((uint8_t)value);
496         }
497         break;
498     case BCDMON:
499         if (s->reg_rtccon & RTC_ENABLE) {
500             s->current_tm.tm_mon = (int)from_bcd((uint8_t)value) - 1;
501         }
502         break;
503     case BCDYEAR:
504         if (s->reg_rtccon & RTC_ENABLE) {
505             /* 3 digits */
506             s->current_tm.tm_year = (int)from_bcd((uint8_t)value) +
507                     (int)from_bcd((uint8_t)((value >> 8) & 0x0f)) * 100;
508         }
509         break;
510 
511     default:
512         qemu_log_mask(LOG_GUEST_ERROR,
513                       "exynos4210.rtc: bad write offset " TARGET_FMT_plx,
514                       offset);
515         break;
516 
517     }
518 }
519 
520 /*
521  * Set default values to timer fields and registers
522  */
523 static void exynos4210_rtc_reset(DeviceState *d)
524 {
525     Exynos4210RTCState *s = EXYNOS4210_RTC(d);
526 
527     qemu_get_timedate(&s->current_tm, 0);
528 
529     DPRINTF("Get time from host: %d-%d-%d %2d:%02d:%02d\n",
530             s->current_tm.tm_year, s->current_tm.tm_mon, s->current_tm.tm_mday,
531             s->current_tm.tm_hour, s->current_tm.tm_min, s->current_tm.tm_sec);
532 
533     s->reg_intp = 0;
534     s->reg_rtccon = 0;
535     s->reg_ticcnt = 0;
536     s->reg_rtcalm = 0;
537     s->reg_almsec = 0;
538     s->reg_almmin = 0;
539     s->reg_almhour = 0;
540     s->reg_almday = 0;
541     s->reg_almmon = 0;
542     s->reg_almyear = 0;
543 
544     s->reg_curticcnt = 0;
545 
546     ptimer_transaction_begin(s->ptimer);
547     exynos4210_rtc_update_freq(s, s->reg_rtccon);
548     ptimer_stop(s->ptimer);
549     ptimer_transaction_commit(s->ptimer);
550     ptimer_transaction_begin(s->ptimer_1Hz);
551     ptimer_stop(s->ptimer_1Hz);
552     ptimer_transaction_commit(s->ptimer_1Hz);
553 }
554 
555 static const MemoryRegionOps exynos4210_rtc_ops = {
556     .read = exynos4210_rtc_read,
557     .write = exynos4210_rtc_write,
558     .endianness = DEVICE_NATIVE_ENDIAN,
559 };
560 
561 /*
562  * RTC timer initialization
563  */
564 static void exynos4210_rtc_init(Object *obj)
565 {
566     Exynos4210RTCState *s = EXYNOS4210_RTC(obj);
567     SysBusDevice *dev = SYS_BUS_DEVICE(obj);
568 
569     s->ptimer = ptimer_init(exynos4210_rtc_tick, s, PTIMER_POLICY_DEFAULT);
570     ptimer_transaction_begin(s->ptimer);
571     ptimer_set_freq(s->ptimer, RTC_BASE_FREQ);
572     exynos4210_rtc_update_freq(s, 0);
573     ptimer_transaction_commit(s->ptimer);
574 
575     s->ptimer_1Hz = ptimer_init(exynos4210_rtc_1Hz_tick,
576                                 s, PTIMER_POLICY_DEFAULT);
577     ptimer_transaction_begin(s->ptimer_1Hz);
578     ptimer_set_freq(s->ptimer_1Hz, RTC_BASE_FREQ);
579     ptimer_transaction_commit(s->ptimer_1Hz);
580 
581     sysbus_init_irq(dev, &s->alm_irq);
582     sysbus_init_irq(dev, &s->tick_irq);
583 
584     memory_region_init_io(&s->iomem, obj, &exynos4210_rtc_ops, s,
585                           "exynos4210-rtc", EXYNOS4210_RTC_REG_MEM_SIZE);
586     sysbus_init_mmio(dev, &s->iomem);
587 }
588 
589 static void exynos4210_rtc_class_init(ObjectClass *klass, void *data)
590 {
591     DeviceClass *dc = DEVICE_CLASS(klass);
592 
593     dc->reset = exynos4210_rtc_reset;
594     dc->vmsd = &vmstate_exynos4210_rtc_state;
595 }
596 
597 static const TypeInfo exynos4210_rtc_info = {
598     .name          = TYPE_EXYNOS4210_RTC,
599     .parent        = TYPE_SYS_BUS_DEVICE,
600     .instance_size = sizeof(Exynos4210RTCState),
601     .instance_init = exynos4210_rtc_init,
602     .class_init    = exynos4210_rtc_class_init,
603 };
604 
605 static void exynos4210_rtc_register_types(void)
606 {
607     type_register_static(&exynos4210_rtc_info);
608 }
609 
610 type_init(exynos4210_rtc_register_types)
611