xref: /openbmc/qemu/hw/misc/mos6522.c (revision 0d98fbb5)
1 /*
2  * QEMU MOS6522 VIA emulation
3  *
4  * Copyright (c) 2004-2007 Fabrice Bellard
5  * Copyright (c) 2007 Jocelyn Mayer
6  * Copyright (c) 2018 Mark Cave-Ayland
7  *
8  * Permission is hereby granted, free of charge, to any person obtaining a copy
9  * of this software and associated documentation files (the "Software"), to deal
10  * in the Software without restriction, including without limitation the rights
11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12  * copies of the Software, and to permit persons to whom the Software is
13  * furnished to do so, subject to the following conditions:
14  *
15  * The above copyright notice and this permission notice shall be included in
16  * all copies or substantial portions of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
21  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24  * THE SOFTWARE.
25  */
26 
27 #include "qemu/osdep.h"
28 #include "hw/input/adb.h"
29 #include "hw/irq.h"
30 #include "hw/misc/mos6522.h"
31 #include "hw/qdev-properties.h"
32 #include "migration/vmstate.h"
33 #include "monitor/monitor.h"
34 #include "monitor/hmp.h"
35 #include "qapi/type-helpers.h"
36 #include "qemu/timer.h"
37 #include "qemu/cutils.h"
38 #include "qemu/log.h"
39 #include "qemu/module.h"
40 #include "trace.h"
41 
42 
43 static const char *mos6522_reg_names[MOS6522_NUM_REGS] = {
44     "ORB", "ORA", "DDRB", "DDRA", "T1CL", "T1CH", "T1LL", "T1LH",
45     "T2CL", "T2CH", "SR", "ACR", "PCR", "IFR", "IER", "ANH"
46 };
47 
48 /* XXX: implement all timer modes */
49 
50 static void mos6522_timer1_update(MOS6522State *s, MOS6522Timer *ti,
51                                   int64_t current_time);
52 static void mos6522_timer2_update(MOS6522State *s, MOS6522Timer *ti,
53                                   int64_t current_time);
54 
55 static void mos6522_update_irq(MOS6522State *s)
56 {
57     if (s->ifr & s->ier) {
58         qemu_irq_raise(s->irq);
59     } else {
60         qemu_irq_lower(s->irq);
61     }
62 }
63 
64 static void mos6522_set_irq(void *opaque, int n, int level)
65 {
66     MOS6522State *s = MOS6522(opaque);
67     int last_level = !!(s->last_irq_levels & (1 << n));
68     uint8_t last_ifr = s->ifr;
69     bool positive_edge = true;
70     int ctrl;
71 
72     /*
73      * SR_INT is managed by mos6522 instances and cleared upon SR
74      * read. It is only the external CA1/2 and CB1/2 lines that
75      * are edge-triggered and latched in IFR
76      */
77     if (n != SR_INT_BIT && level == last_level) {
78         return;
79     }
80 
81     /* Detect negative edge trigger */
82     if (last_level == 1 && level == 0) {
83         positive_edge = false;
84     }
85 
86     switch (n) {
87     case CA2_INT_BIT:
88         ctrl = (s->pcr & CA2_CTRL_MASK) >> CA2_CTRL_SHIFT;
89         if ((positive_edge && (ctrl & C2_POS)) ||
90              (!positive_edge && !(ctrl & C2_POS))) {
91             s->ifr |= 1 << n;
92         }
93         break;
94     case CA1_INT_BIT:
95         ctrl = (s->pcr & CA1_CTRL_MASK) >> CA1_CTRL_SHIFT;
96         if ((positive_edge && (ctrl & C1_POS)) ||
97              (!positive_edge && !(ctrl & C1_POS))) {
98             s->ifr |= 1 << n;
99         }
100         break;
101     case SR_INT_BIT:
102         s->ifr |= 1 << n;
103         break;
104     case CB2_INT_BIT:
105         ctrl = (s->pcr & CB2_CTRL_MASK) >> CB2_CTRL_SHIFT;
106         if ((positive_edge && (ctrl & C2_POS)) ||
107              (!positive_edge && !(ctrl & C2_POS))) {
108             s->ifr |= 1 << n;
109         }
110         break;
111     case CB1_INT_BIT:
112         ctrl = (s->pcr & CB1_CTRL_MASK) >> CB1_CTRL_SHIFT;
113         if ((positive_edge && (ctrl & C1_POS)) ||
114              (!positive_edge && !(ctrl & C1_POS))) {
115             s->ifr |= 1 << n;
116         }
117         break;
118     }
119 
120     if (s->ifr != last_ifr) {
121         mos6522_update_irq(s);
122     }
123 
124     if (level) {
125         s->last_irq_levels |= 1 << n;
126     } else {
127         s->last_irq_levels &= ~(1 << n);
128     }
129 }
130 
131 static uint64_t get_counter_value(MOS6522State *s, MOS6522Timer *ti)
132 {
133     MOS6522DeviceClass *mdc = MOS6522_GET_CLASS(s);
134 
135     if (ti->index == 0) {
136         return mdc->get_timer1_counter_value(s, ti);
137     } else {
138         return mdc->get_timer2_counter_value(s, ti);
139     }
140 }
141 
142 static uint64_t get_load_time(MOS6522State *s, MOS6522Timer *ti)
143 {
144     MOS6522DeviceClass *mdc = MOS6522_GET_CLASS(s);
145 
146     if (ti->index == 0) {
147         return mdc->get_timer1_load_time(s, ti);
148     } else {
149         return mdc->get_timer2_load_time(s, ti);
150     }
151 }
152 
153 static unsigned int get_counter(MOS6522State *s, MOS6522Timer *ti)
154 {
155     int64_t d;
156     unsigned int counter;
157 
158     d = get_counter_value(s, ti);
159 
160     if (ti->index == 0) {
161         /* the timer goes down from latch to -1 (period of latch + 2) */
162         if (d <= (ti->counter_value + 1)) {
163             counter = (ti->counter_value - d) & 0xffff;
164         } else {
165             counter = (d - (ti->counter_value + 1)) % (ti->latch + 2);
166             counter = (ti->latch - counter) & 0xffff;
167         }
168     } else {
169         counter = (ti->counter_value - d) & 0xffff;
170     }
171     return counter;
172 }
173 
174 static void set_counter(MOS6522State *s, MOS6522Timer *ti, unsigned int val)
175 {
176     trace_mos6522_set_counter(1 + ti->index, val);
177     ti->load_time = get_load_time(s, ti);
178     ti->counter_value = val;
179     if (ti->index == 0) {
180         mos6522_timer1_update(s, ti, ti->load_time);
181     } else {
182         mos6522_timer2_update(s, ti, ti->load_time);
183     }
184 }
185 
186 static int64_t get_next_irq_time(MOS6522State *s, MOS6522Timer *ti,
187                                  int64_t current_time)
188 {
189     int64_t d, next_time;
190     unsigned int counter;
191 
192     if (ti->frequency == 0) {
193         return INT64_MAX;
194     }
195 
196     /* current counter value */
197     d = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) - ti->load_time,
198                  ti->frequency, NANOSECONDS_PER_SECOND);
199 
200     /* the timer goes down from latch to -1 (period of latch + 2) */
201     if (d <= (ti->counter_value + 1)) {
202         counter = (ti->counter_value - d) & 0xffff;
203     } else {
204         counter = (d - (ti->counter_value + 1)) % (ti->latch + 2);
205         counter = (ti->latch - counter) & 0xffff;
206     }
207 
208     /* Note: we consider the irq is raised on 0 */
209     if (counter == 0xffff) {
210         next_time = d + ti->latch + 1;
211     } else if (counter == 0) {
212         next_time = d + ti->latch + 2;
213     } else {
214         next_time = d + counter;
215     }
216     trace_mos6522_get_next_irq_time(ti->latch, d, next_time - d);
217     next_time = muldiv64(next_time, NANOSECONDS_PER_SECOND, ti->frequency) +
218                          ti->load_time;
219 
220     if (next_time <= current_time) {
221         next_time = current_time + 1;
222     }
223     return next_time;
224 }
225 
226 static void mos6522_timer1_update(MOS6522State *s, MOS6522Timer *ti,
227                                  int64_t current_time)
228 {
229     if (!ti->timer) {
230         return;
231     }
232     ti->next_irq_time = get_next_irq_time(s, ti, current_time);
233     if ((s->ier & T1_INT) == 0 || (s->acr & T1MODE) != T1MODE_CONT) {
234         timer_del(ti->timer);
235     } else {
236         timer_mod(ti->timer, ti->next_irq_time);
237     }
238 }
239 
240 static void mos6522_timer2_update(MOS6522State *s, MOS6522Timer *ti,
241                                  int64_t current_time)
242 {
243     if (!ti->timer) {
244         return;
245     }
246     ti->next_irq_time = get_next_irq_time(s, ti, current_time);
247     if ((s->ier & T2_INT) == 0) {
248         timer_del(ti->timer);
249     } else {
250         timer_mod(ti->timer, ti->next_irq_time);
251     }
252 }
253 
254 static void mos6522_timer1(void *opaque)
255 {
256     MOS6522State *s = opaque;
257     MOS6522Timer *ti = &s->timers[0];
258 
259     mos6522_timer1_update(s, ti, ti->next_irq_time);
260     s->ifr |= T1_INT;
261     mos6522_update_irq(s);
262 }
263 
264 static void mos6522_timer2(void *opaque)
265 {
266     MOS6522State *s = opaque;
267     MOS6522Timer *ti = &s->timers[1];
268 
269     mos6522_timer2_update(s, ti, ti->next_irq_time);
270     s->ifr |= T2_INT;
271     mos6522_update_irq(s);
272 }
273 
274 static uint64_t mos6522_get_counter_value(MOS6522State *s, MOS6522Timer *ti)
275 {
276     return muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) - ti->load_time,
277                     ti->frequency, NANOSECONDS_PER_SECOND);
278 }
279 
280 static uint64_t mos6522_get_load_time(MOS6522State *s, MOS6522Timer *ti)
281 {
282     uint64_t load_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
283 
284     return load_time;
285 }
286 
287 static void mos6522_portA_write(MOS6522State *s)
288 {
289     qemu_log_mask(LOG_UNIMP, "portA_write unimplemented\n");
290 }
291 
292 static void mos6522_portB_write(MOS6522State *s)
293 {
294     qemu_log_mask(LOG_UNIMP, "portB_write unimplemented\n");
295 }
296 
297 uint64_t mos6522_read(void *opaque, hwaddr addr, unsigned size)
298 {
299     MOS6522State *s = opaque;
300     uint32_t val;
301     int ctrl;
302     int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
303 
304     if (now >= s->timers[0].next_irq_time) {
305         mos6522_timer1_update(s, &s->timers[0], now);
306         s->ifr |= T1_INT;
307     }
308     if (now >= s->timers[1].next_irq_time) {
309         mos6522_timer2_update(s, &s->timers[1], now);
310         s->ifr |= T2_INT;
311     }
312     switch (addr) {
313     case VIA_REG_B:
314         val = s->b;
315         ctrl = (s->pcr & CB2_CTRL_MASK) >> CB2_CTRL_SHIFT;
316         if (!(ctrl & C2_IND)) {
317             s->ifr &= ~CB2_INT;
318         }
319         s->ifr &= ~CB1_INT;
320         mos6522_update_irq(s);
321         break;
322     case VIA_REG_A:
323        qemu_log_mask(LOG_UNIMP, "Read access to register A with handshake");
324        /* fall through */
325     case VIA_REG_ANH:
326         val = s->a;
327         ctrl = (s->pcr & CA2_CTRL_MASK) >> CA2_CTRL_SHIFT;
328         if (!(ctrl & C2_IND)) {
329             s->ifr &= ~CA2_INT;
330         }
331         s->ifr &= ~CA1_INT;
332         mos6522_update_irq(s);
333         break;
334     case VIA_REG_DIRB:
335         val = s->dirb;
336         break;
337     case VIA_REG_DIRA:
338         val = s->dira;
339         break;
340     case VIA_REG_T1CL:
341         val = get_counter(s, &s->timers[0]) & 0xff;
342         s->ifr &= ~T1_INT;
343         mos6522_update_irq(s);
344         break;
345     case VIA_REG_T1CH:
346         val = get_counter(s, &s->timers[0]) >> 8;
347         mos6522_update_irq(s);
348         break;
349     case VIA_REG_T1LL:
350         val = s->timers[0].latch & 0xff;
351         break;
352     case VIA_REG_T1LH:
353         /* XXX: check this */
354         val = (s->timers[0].latch >> 8) & 0xff;
355         break;
356     case VIA_REG_T2CL:
357         val = get_counter(s, &s->timers[1]) & 0xff;
358         s->ifr &= ~T2_INT;
359         mos6522_update_irq(s);
360         break;
361     case VIA_REG_T2CH:
362         val = get_counter(s, &s->timers[1]) >> 8;
363         break;
364     case VIA_REG_SR:
365         val = s->sr;
366         s->ifr &= ~SR_INT;
367         mos6522_update_irq(s);
368         break;
369     case VIA_REG_ACR:
370         val = s->acr;
371         break;
372     case VIA_REG_PCR:
373         val = s->pcr;
374         break;
375     case VIA_REG_IFR:
376         val = s->ifr;
377         if (s->ifr & s->ier) {
378             val |= 0x80;
379         }
380         break;
381     case VIA_REG_IER:
382         val = s->ier | 0x80;
383         break;
384     default:
385         g_assert_not_reached();
386     }
387 
388     if (addr != VIA_REG_IFR || val != 0) {
389         trace_mos6522_read(addr, mos6522_reg_names[addr], val);
390     }
391 
392     return val;
393 }
394 
395 void mos6522_write(void *opaque, hwaddr addr, uint64_t val, unsigned size)
396 {
397     MOS6522State *s = opaque;
398     MOS6522DeviceClass *mdc = MOS6522_GET_CLASS(s);
399     int ctrl;
400 
401     trace_mos6522_write(addr, mos6522_reg_names[addr], val);
402 
403     switch (addr) {
404     case VIA_REG_B:
405         s->b = (s->b & ~s->dirb) | (val & s->dirb);
406         mdc->portB_write(s);
407         ctrl = (s->pcr & CB2_CTRL_MASK) >> CB2_CTRL_SHIFT;
408         if (!(ctrl & C2_IND)) {
409             s->ifr &= ~CB2_INT;
410         }
411         s->ifr &= ~CB1_INT;
412         mos6522_update_irq(s);
413         break;
414     case VIA_REG_A:
415        qemu_log_mask(LOG_UNIMP, "Write access to register A with handshake");
416        /* fall through */
417     case VIA_REG_ANH:
418         s->a = (s->a & ~s->dira) | (val & s->dira);
419         mdc->portA_write(s);
420         ctrl = (s->pcr & CA2_CTRL_MASK) >> CA2_CTRL_SHIFT;
421         if (!(ctrl & C2_IND)) {
422             s->ifr &= ~CA2_INT;
423         }
424         s->ifr &= ~CA1_INT;
425         mos6522_update_irq(s);
426         break;
427     case VIA_REG_DIRB:
428         s->dirb = val;
429         break;
430     case VIA_REG_DIRA:
431         s->dira = val;
432         break;
433     case VIA_REG_T1CL:
434         s->timers[0].latch = (s->timers[0].latch & 0xff00) | val;
435         mos6522_timer1_update(s, &s->timers[0],
436                               qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
437         break;
438     case VIA_REG_T1CH:
439         s->timers[0].latch = (s->timers[0].latch & 0xff) | (val << 8);
440         s->ifr &= ~T1_INT;
441         set_counter(s, &s->timers[0], s->timers[0].latch);
442         break;
443     case VIA_REG_T1LL:
444         s->timers[0].latch = (s->timers[0].latch & 0xff00) | val;
445         mos6522_timer1_update(s, &s->timers[0],
446                               qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
447         break;
448     case VIA_REG_T1LH:
449         s->timers[0].latch = (s->timers[0].latch & 0xff) | (val << 8);
450         s->ifr &= ~T1_INT;
451         mos6522_timer1_update(s, &s->timers[0],
452                               qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
453         break;
454     case VIA_REG_T2CL:
455         s->timers[1].latch = (s->timers[1].latch & 0xff00) | val;
456         break;
457     case VIA_REG_T2CH:
458         /* To ensure T2 generates an interrupt on zero crossing with the
459            common timer code, write the value directly from the latch to
460            the counter */
461         s->timers[1].latch = (s->timers[1].latch & 0xff) | (val << 8);
462         s->ifr &= ~T2_INT;
463         set_counter(s, &s->timers[1], s->timers[1].latch);
464         break;
465     case VIA_REG_SR:
466         s->sr = val;
467         break;
468     case VIA_REG_ACR:
469         s->acr = val;
470         mos6522_timer1_update(s, &s->timers[0],
471                               qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
472         break;
473     case VIA_REG_PCR:
474         s->pcr = val;
475         break;
476     case VIA_REG_IFR:
477         /* reset bits */
478         s->ifr &= ~val;
479         mos6522_update_irq(s);
480         break;
481     case VIA_REG_IER:
482         if (val & IER_SET) {
483             /* set bits */
484             s->ier |= val & 0x7f;
485         } else {
486             /* reset bits */
487             s->ier &= ~val;
488         }
489         mos6522_update_irq(s);
490         /* if IER is modified starts needed timers */
491         mos6522_timer1_update(s, &s->timers[0],
492                               qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
493         mos6522_timer2_update(s, &s->timers[1],
494                               qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
495         break;
496     default:
497         g_assert_not_reached();
498     }
499 }
500 
501 static int qmp_x_query_via_foreach(Object *obj, void *opaque)
502 {
503     GString *buf = opaque;
504 
505     if (object_dynamic_cast(obj, TYPE_MOS6522)) {
506         MOS6522State *s = MOS6522(obj);
507         int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
508         uint16_t t1counter = get_counter(s, &s->timers[0]);
509         uint16_t t2counter = get_counter(s, &s->timers[1]);
510 
511         g_string_append_printf(buf, "%s:\n", object_get_typename(obj));
512 
513         g_string_append_printf(buf, "  Registers:\n");
514         g_string_append_printf(buf, "    %-*s:    0x%x\n", 4,
515                                mos6522_reg_names[0], s->b);
516         g_string_append_printf(buf, "    %-*s:    0x%x\n", 4,
517                                mos6522_reg_names[1], s->a);
518         g_string_append_printf(buf, "    %-*s:    0x%x\n", 4,
519                                mos6522_reg_names[2], s->dirb);
520         g_string_append_printf(buf, "    %-*s:    0x%x\n", 4,
521                                mos6522_reg_names[3], s->dira);
522         g_string_append_printf(buf, "    %-*s:    0x%x\n", 4,
523                                mos6522_reg_names[4], t1counter & 0xff);
524         g_string_append_printf(buf, "    %-*s:    0x%x\n", 4,
525                                mos6522_reg_names[5], t1counter >> 8);
526         g_string_append_printf(buf, "    %-*s:    0x%x\n", 4,
527                                mos6522_reg_names[6],
528                                s->timers[0].latch & 0xff);
529         g_string_append_printf(buf, "    %-*s:    0x%x\n", 4,
530                                mos6522_reg_names[7],
531                                s->timers[0].latch >> 8);
532         g_string_append_printf(buf, "    %-*s:    0x%x\n", 4,
533                                mos6522_reg_names[8], t2counter & 0xff);
534         g_string_append_printf(buf, "    %-*s:    0x%x\n", 4,
535                                mos6522_reg_names[9], t2counter >> 8);
536         g_string_append_printf(buf, "    %-*s:    0x%x\n", 4,
537                                mos6522_reg_names[10], s->sr);
538         g_string_append_printf(buf, "    %-*s:    0x%x\n", 4,
539                                mos6522_reg_names[11], s->acr);
540         g_string_append_printf(buf, "    %-*s:    0x%x\n", 4,
541                                mos6522_reg_names[12], s->pcr);
542         g_string_append_printf(buf, "    %-*s:    0x%x\n", 4,
543                                mos6522_reg_names[13], s->ifr);
544         g_string_append_printf(buf, "    %-*s:    0x%x\n", 4,
545                                mos6522_reg_names[14], s->ier);
546 
547         g_string_append_printf(buf, "  Timers:\n");
548         g_string_append_printf(buf, "    Using current time now(ns)=%"PRId64
549                                     "\n", now);
550         g_string_append_printf(buf, "    T1 freq(hz)=%"PRId64
551                                " mode=%s"
552                                " counter=0x%x"
553                                " latch=0x%x\n"
554                                "       load_time(ns)=%"PRId64
555                                " next_irq_time(ns)=%"PRId64 "\n",
556                                s->timers[0].frequency,
557                                ((s->acr & T1MODE) == T1MODE_CONT) ? "continuous"
558                                                                   : "one-shot",
559                                t1counter,
560                                s->timers[0].latch,
561                                s->timers[0].load_time,
562                                get_next_irq_time(s, &s->timers[0], now));
563         g_string_append_printf(buf, "    T2 freq(hz)=%"PRId64
564                                " mode=%s"
565                                " counter=0x%x"
566                                " latch=0x%x\n"
567                                "       load_time(ns)=%"PRId64
568                                " next_irq_time(ns)=%"PRId64 "\n",
569                                s->timers[1].frequency,
570                                "one-shot",
571                                t2counter,
572                                s->timers[1].latch,
573                                s->timers[1].load_time,
574                                get_next_irq_time(s, &s->timers[1], now));
575     }
576 
577     return 0;
578 }
579 
580 static HumanReadableText *qmp_x_query_via(Error **errp)
581 {
582     g_autoptr(GString) buf = g_string_new("");
583 
584     object_child_foreach_recursive(object_get_root(),
585                                    qmp_x_query_via_foreach, buf);
586 
587     return human_readable_text_from_str(buf);
588 }
589 
590 void hmp_info_via(Monitor *mon, const QDict *qdict)
591 {
592     Error *err = NULL;
593     g_autoptr(HumanReadableText) info = qmp_x_query_via(&err);
594 
595     if (hmp_handle_error(mon, err)) {
596         return;
597     }
598     monitor_printf(mon, "%s", info->human_readable_text);
599 }
600 
601 static const MemoryRegionOps mos6522_ops = {
602     .read = mos6522_read,
603     .write = mos6522_write,
604     .endianness = DEVICE_NATIVE_ENDIAN,
605     .valid = {
606         .min_access_size = 1,
607         .max_access_size = 1,
608     },
609 };
610 
611 static const VMStateDescription vmstate_mos6522_timer = {
612     .name = "mos6522_timer",
613     .version_id = 0,
614     .minimum_version_id = 0,
615     .fields = (VMStateField[]) {
616         VMSTATE_UINT16(latch, MOS6522Timer),
617         VMSTATE_UINT16(counter_value, MOS6522Timer),
618         VMSTATE_INT64(load_time, MOS6522Timer),
619         VMSTATE_INT64(next_irq_time, MOS6522Timer),
620         VMSTATE_TIMER_PTR(timer, MOS6522Timer),
621         VMSTATE_END_OF_LIST()
622     }
623 };
624 
625 const VMStateDescription vmstate_mos6522 = {
626     .name = "mos6522",
627     .version_id = 1,
628     .minimum_version_id = 1,
629     .fields = (VMStateField[]) {
630         VMSTATE_UINT8(a, MOS6522State),
631         VMSTATE_UINT8(b, MOS6522State),
632         VMSTATE_UINT8(dira, MOS6522State),
633         VMSTATE_UINT8(dirb, MOS6522State),
634         VMSTATE_UINT8(sr, MOS6522State),
635         VMSTATE_UINT8(acr, MOS6522State),
636         VMSTATE_UINT8(pcr, MOS6522State),
637         VMSTATE_UINT8(ifr, MOS6522State),
638         VMSTATE_UINT8(ier, MOS6522State),
639         VMSTATE_UINT8(last_irq_levels, MOS6522State),
640         VMSTATE_STRUCT_ARRAY(timers, MOS6522State, 2, 0,
641                              vmstate_mos6522_timer, MOS6522Timer),
642         VMSTATE_END_OF_LIST()
643     }
644 };
645 
646 static void mos6522_reset(DeviceState *dev)
647 {
648     MOS6522State *s = MOS6522(dev);
649 
650     s->b = 0;
651     s->a = 0;
652     s->dirb = 0xff;
653     s->dira = 0;
654     s->sr = 0;
655     s->acr = 0;
656     s->pcr = 0;
657     s->ifr = 0;
658     s->ier = 0;
659     /* s->ier = T1_INT | SR_INT; */
660 
661     s->timers[0].frequency = s->frequency;
662     s->timers[0].latch = 0xffff;
663     set_counter(s, &s->timers[0], 0xffff);
664     timer_del(s->timers[0].timer);
665 
666     s->timers[1].frequency = s->frequency;
667     s->timers[1].latch = 0xffff;
668     timer_del(s->timers[1].timer);
669 }
670 
671 static void mos6522_init(Object *obj)
672 {
673     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
674     MOS6522State *s = MOS6522(obj);
675     int i;
676 
677     memory_region_init_io(&s->mem, obj, &mos6522_ops, s, "mos6522",
678                           MOS6522_NUM_REGS);
679     sysbus_init_mmio(sbd, &s->mem);
680     sysbus_init_irq(sbd, &s->irq);
681 
682     for (i = 0; i < ARRAY_SIZE(s->timers); i++) {
683         s->timers[i].index = i;
684     }
685 
686     s->timers[0].timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, mos6522_timer1, s);
687     s->timers[1].timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, mos6522_timer2, s);
688 
689     qdev_init_gpio_in(DEVICE(obj), mos6522_set_irq, VIA_NUM_INTS);
690 }
691 
692 static void mos6522_finalize(Object *obj)
693 {
694     MOS6522State *s = MOS6522(obj);
695 
696     timer_free(s->timers[0].timer);
697     timer_free(s->timers[1].timer);
698 }
699 
700 static Property mos6522_properties[] = {
701     DEFINE_PROP_UINT64("frequency", MOS6522State, frequency, 0),
702     DEFINE_PROP_END_OF_LIST()
703 };
704 
705 static void mos6522_class_init(ObjectClass *oc, void *data)
706 {
707     DeviceClass *dc = DEVICE_CLASS(oc);
708     MOS6522DeviceClass *mdc = MOS6522_CLASS(oc);
709 
710     dc->reset = mos6522_reset;
711     dc->vmsd = &vmstate_mos6522;
712     device_class_set_props(dc, mos6522_properties);
713     mdc->portB_write = mos6522_portB_write;
714     mdc->portA_write = mos6522_portA_write;
715     mdc->get_timer1_counter_value = mos6522_get_counter_value;
716     mdc->get_timer2_counter_value = mos6522_get_counter_value;
717     mdc->get_timer1_load_time = mos6522_get_load_time;
718     mdc->get_timer2_load_time = mos6522_get_load_time;
719 }
720 
721 static const TypeInfo mos6522_type_info = {
722     .name = TYPE_MOS6522,
723     .parent = TYPE_SYS_BUS_DEVICE,
724     .instance_size = sizeof(MOS6522State),
725     .instance_init = mos6522_init,
726     .instance_finalize = mos6522_finalize,
727     .abstract = true,
728     .class_size = sizeof(MOS6522DeviceClass),
729     .class_init = mos6522_class_init,
730 };
731 
732 static void mos6522_register_types(void)
733 {
734     type_register_static(&mos6522_type_info);
735 }
736 
737 type_init(mos6522_register_types)
738