xref: /openbmc/qemu/hw/timer/renesas_tmr.c (revision ee2e67da)
1 /*
2  * Renesas 8bit timer
3  *
4  * Datasheet: RX62N Group, RX621 Group User's Manual: Hardware
5  *            (Rev.1.40 R01UH0033EJ0140)
6  *
7  * Copyright (c) 2019 Yoshinori Sato
8  *
9  * SPDX-License-Identifier: GPL-2.0-or-later
10  *
11  * This program is free software; you can redistribute it and/or modify it
12  * under the terms and conditions of the GNU General Public License,
13  * version 2 or later, as published by the Free Software Foundation.
14  *
15  * This program is distributed in the hope it will be useful, but WITHOUT
16  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
17  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
18  * more details.
19  *
20  * You should have received a copy of the GNU General Public License along with
21  * this program.  If not, see <http://www.gnu.org/licenses/>.
22  */
23 
24 #include "qemu/osdep.h"
25 #include "qemu/log.h"
26 #include "hw/irq.h"
27 #include "hw/registerfields.h"
28 #include "hw/qdev-properties.h"
29 #include "hw/timer/renesas_tmr.h"
30 #include "migration/vmstate.h"
31 
32 REG8(TCR, 0)
33   FIELD(TCR, CCLR,  3, 2)
34   FIELD(TCR, OVIE,  5, 1)
35   FIELD(TCR, CMIEA, 6, 1)
36   FIELD(TCR, CMIEB, 7, 1)
37 REG8(TCSR, 2)
38   FIELD(TCSR, OSA,  0, 2)
39   FIELD(TCSR, OSB,  2, 2)
40   FIELD(TCSR, ADTE, 4, 2)
41 REG8(TCORA, 4)
42 REG8(TCORB, 6)
43 REG8(TCNT, 8)
44 REG8(TCCR, 10)
45   FIELD(TCCR, CKS,   0, 3)
46   FIELD(TCCR, CSS,   3, 2)
47   FIELD(TCCR, TMRIS, 7, 1)
48 
49 #define CSS_EXTERNAL  0x00
50 #define CSS_INTERNAL  0x01
51 #define CSS_INVALID   0x02
52 #define CSS_CASCADING 0x03
53 #define CCLR_A    0x01
54 #define CCLR_B    0x02
55 
56 static const int clkdiv[] = {0, 1, 2, 8, 32, 64, 1024, 8192};
57 
58 static uint8_t concat_reg(uint8_t *reg)
59 {
60     return (reg[0] << 8) | reg[1];
61 }
62 
63 static void update_events(RTMRState *tmr, int ch)
64 {
65     uint16_t diff[TMR_NR_EVENTS], min;
66     int64_t next_time;
67     int i, event;
68 
69     if (tmr->tccr[ch] == 0) {
70         return ;
71     }
72     if (FIELD_EX8(tmr->tccr[ch], TCCR, CSS) == 0) {
73         /* external clock mode */
74         /* event not happened */
75         return ;
76     }
77     if (FIELD_EX8(tmr->tccr[0], TCCR, CSS) == CSS_CASCADING) {
78         /* cascading mode */
79         if (ch == 1) {
80             tmr->next[ch] = none;
81             return ;
82         }
83         diff[cmia] = concat_reg(tmr->tcora) - concat_reg(tmr->tcnt);
84         diff[cmib] = concat_reg(tmr->tcorb) - concat_reg(tmr->tcnt);
85         diff[ovi] = 0x10000 - concat_reg(tmr->tcnt);
86     } else {
87         /* separate mode */
88         diff[cmia] = tmr->tcora[ch] - tmr->tcnt[ch];
89         diff[cmib] = tmr->tcorb[ch] - tmr->tcnt[ch];
90         diff[ovi] = 0x100 - tmr->tcnt[ch];
91     }
92     /* Search for the most recently occurring event. */
93     for (event = 0, min = diff[0], i = 1; i < none; i++) {
94         if (min > diff[i]) {
95             event = i;
96             min = diff[i];
97         }
98     }
99     tmr->next[ch] = event;
100     next_time = diff[event];
101     next_time *= clkdiv[FIELD_EX8(tmr->tccr[ch], TCCR, CKS)];
102     next_time *= NANOSECONDS_PER_SECOND;
103     next_time /= tmr->input_freq;
104     next_time += qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
105     timer_mod(&tmr->timer[ch], next_time);
106 }
107 
108 static int elapsed_time(RTMRState *tmr, int ch, int64_t delta)
109 {
110     int divrate = clkdiv[FIELD_EX8(tmr->tccr[ch], TCCR, CKS)];
111     int et;
112 
113     tmr->div_round[ch] += delta;
114     if (divrate > 0) {
115         et = tmr->div_round[ch] / divrate;
116         tmr->div_round[ch] %= divrate;
117     } else {
118         /* disble clock. so no update */
119         et = 0;
120     }
121     return et;
122 }
123 
124 static uint16_t read_tcnt(RTMRState *tmr, unsigned size, int ch)
125 {
126     int64_t delta, now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
127     int elapsed, ovf = 0;
128     uint16_t tcnt[2];
129     uint32_t ret;
130 
131     delta = (now - tmr->tick) * NANOSECONDS_PER_SECOND / tmr->input_freq;
132     if (delta > 0) {
133         tmr->tick = now;
134 
135         switch (FIELD_EX8(tmr->tccr[1], TCCR, CSS)) {
136         case CSS_INTERNAL:
137             /* timer1 count update */
138             elapsed = elapsed_time(tmr, 1, delta);
139             if (elapsed >= 0x100) {
140                 ovf = elapsed >> 8;
141             }
142             tcnt[1] = tmr->tcnt[1] + (elapsed & 0xff);
143             break;
144         case CSS_INVALID: /* guest error to have set this */
145         case CSS_EXTERNAL: /* QEMU doesn't implement these */
146         case CSS_CASCADING:
147             tcnt[1] = tmr->tcnt[1];
148             break;
149         }
150         switch (FIELD_EX8(tmr->tccr[0], TCCR, CSS)) {
151         case CSS_INTERNAL:
152             elapsed = elapsed_time(tmr, 0, delta);
153             tcnt[0] = tmr->tcnt[0] + elapsed;
154             break;
155         case CSS_CASCADING:
156             tcnt[0] = tmr->tcnt[0] + ovf;
157             break;
158         case CSS_INVALID: /* guest error to have set this */
159         case CSS_EXTERNAL: /* QEMU doesn't implement this */
160             tcnt[0] = tmr->tcnt[0];
161             break;
162         }
163     } else {
164         tcnt[0] = tmr->tcnt[0];
165         tcnt[1] = tmr->tcnt[1];
166     }
167     if (size == 1) {
168         return tcnt[ch];
169     } else {
170         ret = 0;
171         ret = deposit32(ret, 0, 8, tcnt[1]);
172         ret = deposit32(ret, 8, 8, tcnt[0]);
173         return ret;
174     }
175 }
176 
177 static uint8_t read_tccr(uint8_t r)
178 {
179     uint8_t tccr = 0;
180     tccr = FIELD_DP8(tccr, TCCR, TMRIS,
181                      FIELD_EX8(r, TCCR, TMRIS));
182     tccr = FIELD_DP8(tccr, TCCR, CSS,
183                      FIELD_EX8(r, TCCR, CSS));
184     tccr = FIELD_DP8(tccr, TCCR, CKS,
185                      FIELD_EX8(r, TCCR, CKS));
186     return tccr;
187 }
188 
189 static uint64_t tmr_read(void *opaque, hwaddr addr, unsigned size)
190 {
191     RTMRState *tmr = opaque;
192     int ch = addr & 1;
193     uint64_t ret;
194 
195     if (size == 2 && (ch != 0 || addr == A_TCR || addr == A_TCSR)) {
196         qemu_log_mask(LOG_GUEST_ERROR, "renesas_tmr: Invalid read size 0x%"
197                                        HWADDR_PRIX "\n",
198                       addr);
199         return UINT64_MAX;
200     }
201     switch (addr & 0x0e) {
202     case A_TCR:
203         ret = 0;
204         ret = FIELD_DP8(ret, TCR, CCLR,
205                         FIELD_EX8(tmr->tcr[ch], TCR, CCLR));
206         ret = FIELD_DP8(ret, TCR, OVIE,
207                         FIELD_EX8(tmr->tcr[ch], TCR, OVIE));
208         ret = FIELD_DP8(ret, TCR, CMIEA,
209                         FIELD_EX8(tmr->tcr[ch], TCR, CMIEA));
210         ret = FIELD_DP8(ret, TCR, CMIEB,
211                         FIELD_EX8(tmr->tcr[ch], TCR, CMIEB));
212         return ret;
213     case A_TCSR:
214         ret = 0;
215         ret = FIELD_DP8(ret, TCSR, OSA,
216                         FIELD_EX8(tmr->tcsr[ch], TCSR, OSA));
217         ret = FIELD_DP8(ret, TCSR, OSB,
218                         FIELD_EX8(tmr->tcsr[ch], TCSR, OSB));
219         switch (ch) {
220         case 0:
221             ret = FIELD_DP8(ret, TCSR, ADTE,
222                             FIELD_EX8(tmr->tcsr[ch], TCSR, ADTE));
223             break;
224         case 1: /* CH1 ADTE unimplement always 1 */
225             ret = FIELD_DP8(ret, TCSR, ADTE, 1);
226             break;
227         }
228         return ret;
229     case A_TCORA:
230         if (size == 1) {
231             return tmr->tcora[ch];
232         } else if (ch == 0) {
233             return concat_reg(tmr->tcora);
234         }
235         /* fall through */
236     case A_TCORB:
237         if (size == 1) {
238             return tmr->tcorb[ch];
239         } else {
240             return concat_reg(tmr->tcorb);
241         }
242     case A_TCNT:
243         return read_tcnt(tmr, size, ch);
244     case A_TCCR:
245         if (size == 1) {
246             return read_tccr(tmr->tccr[ch]);
247         } else {
248             return read_tccr(tmr->tccr[0]) << 8 | read_tccr(tmr->tccr[1]);
249         }
250     default:
251         qemu_log_mask(LOG_UNIMP, "renesas_tmr: Register 0x%" HWADDR_PRIX
252                                  " not implemented\n",
253                       addr);
254         break;
255     }
256     return UINT64_MAX;
257 }
258 
259 static void tmr_write_count(RTMRState *tmr, int ch, unsigned size,
260                             uint8_t *reg, uint64_t val)
261 {
262     if (size == 1) {
263         reg[ch] = val;
264         update_events(tmr, ch);
265     } else {
266         reg[0] = extract32(val, 8, 8);
267         reg[1] = extract32(val, 0, 8);
268         update_events(tmr, 0);
269         update_events(tmr, 1);
270     }
271 }
272 
273 static void tmr_write(void *opaque, hwaddr addr, uint64_t val, unsigned size)
274 {
275     RTMRState *tmr = opaque;
276     int ch = addr & 1;
277 
278     if (size == 2 && (ch != 0 || addr == A_TCR || addr == A_TCSR)) {
279         qemu_log_mask(LOG_GUEST_ERROR,
280                       "renesas_tmr: Invalid write size 0x%" HWADDR_PRIX "\n",
281                       addr);
282         return;
283     }
284     switch (addr & 0x0e) {
285     case A_TCR:
286         tmr->tcr[ch] = val;
287         break;
288     case A_TCSR:
289         tmr->tcsr[ch] = val;
290         break;
291     case A_TCORA:
292         tmr_write_count(tmr, ch, size, tmr->tcora, val);
293         break;
294     case A_TCORB:
295         tmr_write_count(tmr, ch, size, tmr->tcorb, val);
296         break;
297     case A_TCNT:
298         tmr_write_count(tmr, ch, size, tmr->tcnt, val);
299         break;
300     case A_TCCR:
301         tmr_write_count(tmr, ch, size, tmr->tccr, val);
302         break;
303     default:
304         qemu_log_mask(LOG_UNIMP, "renesas_tmr: Register 0x%" HWADDR_PRIX
305                                  " not implemented\n",
306                       addr);
307         break;
308     }
309 }
310 
311 static const MemoryRegionOps tmr_ops = {
312     .write = tmr_write,
313     .read  = tmr_read,
314     .endianness = DEVICE_LITTLE_ENDIAN,
315     .impl = {
316         .min_access_size = 1,
317         .max_access_size = 2,
318     },
319     .valid = {
320         .min_access_size = 1,
321         .max_access_size = 2,
322     },
323 };
324 
325 static void timer_events(RTMRState *tmr, int ch);
326 
327 static uint16_t issue_event(RTMRState *tmr, int ch, int sz,
328                         uint16_t tcnt, uint16_t tcora, uint16_t tcorb)
329 {
330     uint16_t ret = tcnt;
331 
332     switch (tmr->next[ch]) {
333     case none:
334         break;
335     case cmia:
336         if (tcnt >= tcora) {
337             if (FIELD_EX8(tmr->tcr[ch], TCR, CCLR) == CCLR_A) {
338                 ret = tcnt - tcora;
339             }
340             if (FIELD_EX8(tmr->tcr[ch], TCR, CMIEA)) {
341                 qemu_irq_pulse(tmr->cmia[ch]);
342             }
343             if (sz == 8 && ch == 0 &&
344                 FIELD_EX8(tmr->tccr[1], TCCR, CSS) == CSS_CASCADING) {
345                 tmr->tcnt[1]++;
346                 timer_events(tmr, 1);
347             }
348         }
349         break;
350     case cmib:
351         if (tcnt >= tcorb) {
352             if (FIELD_EX8(tmr->tcr[ch], TCR, CCLR) == CCLR_B) {
353                 ret = tcnt - tcorb;
354             }
355             if (FIELD_EX8(tmr->tcr[ch], TCR, CMIEB)) {
356                 qemu_irq_pulse(tmr->cmib[ch]);
357             }
358         }
359         break;
360     case ovi:
361         if ((tcnt >= (1 << sz)) && FIELD_EX8(tmr->tcr[ch], TCR, OVIE)) {
362             qemu_irq_pulse(tmr->ovi[ch]);
363         }
364         break;
365     default:
366         g_assert_not_reached();
367     }
368     return ret;
369 }
370 
371 static void timer_events(RTMRState *tmr, int ch)
372 {
373     uint16_t tcnt;
374 
375     tmr->tcnt[ch] = read_tcnt(tmr, 1, ch);
376     if (FIELD_EX8(tmr->tccr[0], TCCR, CSS) != CSS_CASCADING) {
377         tmr->tcnt[ch] = issue_event(tmr, ch, 8,
378                                     tmr->tcnt[ch],
379                                     tmr->tcora[ch],
380                                     tmr->tcorb[ch]) & 0xff;
381     } else {
382         if (ch == 1) {
383             return ;
384         }
385         tcnt = issue_event(tmr, ch, 16,
386                            concat_reg(tmr->tcnt),
387                            concat_reg(tmr->tcora),
388                            concat_reg(tmr->tcorb));
389         tmr->tcnt[0] = (tcnt >> 8) & 0xff;
390         tmr->tcnt[1] = tcnt & 0xff;
391     }
392     update_events(tmr, ch);
393 }
394 
395 static void timer_event0(void *opaque)
396 {
397     RTMRState *tmr = opaque;
398 
399     timer_events(tmr, 0);
400 }
401 
402 static void timer_event1(void *opaque)
403 {
404     RTMRState *tmr = opaque;
405 
406     timer_events(tmr, 1);
407 }
408 
409 static void rtmr_reset(DeviceState *dev)
410 {
411     RTMRState *tmr = RTMR(dev);
412     tmr->tcr[0]   = tmr->tcr[1]   = 0x00;
413     tmr->tcsr[0]  = 0x00;
414     tmr->tcsr[1]  = 0x10;
415     tmr->tcnt[0]  = tmr->tcnt[1]  = 0x00;
416     tmr->tcora[0] = tmr->tcora[1] = 0xff;
417     tmr->tcorb[0] = tmr->tcorb[1] = 0xff;
418     tmr->tccr[0]  = tmr->tccr[1]  = 0x00;
419     tmr->next[0]  = tmr->next[1]  = none;
420     tmr->tick = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
421 }
422 
423 static void rtmr_init(Object *obj)
424 {
425     SysBusDevice *d = SYS_BUS_DEVICE(obj);
426     RTMRState *tmr = RTMR(obj);
427     int i;
428 
429     memory_region_init_io(&tmr->memory, OBJECT(tmr), &tmr_ops,
430                           tmr, "renesas-tmr", 0x10);
431     sysbus_init_mmio(d, &tmr->memory);
432 
433     for (i = 0; i < ARRAY_SIZE(tmr->ovi); i++) {
434         sysbus_init_irq(d, &tmr->cmia[i]);
435         sysbus_init_irq(d, &tmr->cmib[i]);
436         sysbus_init_irq(d, &tmr->ovi[i]);
437     }
438     timer_init_ns(&tmr->timer[0], QEMU_CLOCK_VIRTUAL, timer_event0, tmr);
439     timer_init_ns(&tmr->timer[1], QEMU_CLOCK_VIRTUAL, timer_event1, tmr);
440 }
441 
442 static const VMStateDescription vmstate_rtmr = {
443     .name = "rx-tmr",
444     .version_id = 1,
445     .minimum_version_id = 1,
446     .fields = (VMStateField[]) {
447         VMSTATE_INT64(tick, RTMRState),
448         VMSTATE_UINT8_ARRAY(tcnt, RTMRState, TMR_CH),
449         VMSTATE_UINT8_ARRAY(tcora, RTMRState, TMR_CH),
450         VMSTATE_UINT8_ARRAY(tcorb, RTMRState, TMR_CH),
451         VMSTATE_UINT8_ARRAY(tcr, RTMRState, TMR_CH),
452         VMSTATE_UINT8_ARRAY(tccr, RTMRState, TMR_CH),
453         VMSTATE_UINT8_ARRAY(tcor, RTMRState, TMR_CH),
454         VMSTATE_UINT8_ARRAY(tcsr, RTMRState, TMR_CH),
455         VMSTATE_INT64_ARRAY(div_round, RTMRState, TMR_CH),
456         VMSTATE_UINT8_ARRAY(next, RTMRState, TMR_CH),
457         VMSTATE_TIMER_ARRAY(timer, RTMRState, TMR_CH),
458         VMSTATE_END_OF_LIST()
459     }
460 };
461 
462 static Property rtmr_properties[] = {
463     DEFINE_PROP_UINT64("input-freq", RTMRState, input_freq, 0),
464     DEFINE_PROP_END_OF_LIST(),
465 };
466 
467 static void rtmr_class_init(ObjectClass *klass, void *data)
468 {
469     DeviceClass *dc = DEVICE_CLASS(klass);
470 
471     dc->vmsd = &vmstate_rtmr;
472     dc->reset = rtmr_reset;
473     device_class_set_props(dc, rtmr_properties);
474 }
475 
476 static const TypeInfo rtmr_info = {
477     .name = TYPE_RENESAS_TMR,
478     .parent = TYPE_SYS_BUS_DEVICE,
479     .instance_size = sizeof(RTMRState),
480     .instance_init = rtmr_init,
481     .class_init = rtmr_class_init,
482 };
483 
484 static void rtmr_register_types(void)
485 {
486     type_register_static(&rtmr_info);
487 }
488 
489 type_init(rtmr_register_types)
490