xref: /openbmc/qemu/hw/timer/renesas_tmr.c (revision 19f4ed36)
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         default:
150             g_assert_not_reached();
151         }
152         switch (FIELD_EX8(tmr->tccr[0], TCCR, CSS)) {
153         case CSS_INTERNAL:
154             elapsed = elapsed_time(tmr, 0, delta);
155             tcnt[0] = tmr->tcnt[0] + elapsed;
156             break;
157         case CSS_CASCADING:
158             tcnt[0] = tmr->tcnt[0] + ovf;
159             break;
160         case CSS_INVALID: /* guest error to have set this */
161         case CSS_EXTERNAL: /* QEMU doesn't implement this */
162             tcnt[0] = tmr->tcnt[0];
163             break;
164         default:
165             g_assert_not_reached();
166         }
167     } else {
168         tcnt[0] = tmr->tcnt[0];
169         tcnt[1] = tmr->tcnt[1];
170     }
171     if (size == 1) {
172         return tcnt[ch];
173     } else {
174         ret = 0;
175         ret = deposit32(ret, 0, 8, tcnt[1]);
176         ret = deposit32(ret, 8, 8, tcnt[0]);
177         return ret;
178     }
179 }
180 
181 static uint8_t read_tccr(uint8_t r)
182 {
183     uint8_t tccr = 0;
184     tccr = FIELD_DP8(tccr, TCCR, TMRIS,
185                      FIELD_EX8(r, TCCR, TMRIS));
186     tccr = FIELD_DP8(tccr, TCCR, CSS,
187                      FIELD_EX8(r, TCCR, CSS));
188     tccr = FIELD_DP8(tccr, TCCR, CKS,
189                      FIELD_EX8(r, TCCR, CKS));
190     return tccr;
191 }
192 
193 static uint64_t tmr_read(void *opaque, hwaddr addr, unsigned size)
194 {
195     RTMRState *tmr = opaque;
196     int ch = addr & 1;
197     uint64_t ret;
198 
199     if (size == 2 && (ch != 0 || addr == A_TCR || addr == A_TCSR)) {
200         qemu_log_mask(LOG_GUEST_ERROR, "renesas_tmr: Invalid read size 0x%"
201                                        HWADDR_PRIX "\n",
202                       addr);
203         return UINT64_MAX;
204     }
205     switch (addr & 0x0e) {
206     case A_TCR:
207         ret = 0;
208         ret = FIELD_DP8(ret, TCR, CCLR,
209                         FIELD_EX8(tmr->tcr[ch], TCR, CCLR));
210         ret = FIELD_DP8(ret, TCR, OVIE,
211                         FIELD_EX8(tmr->tcr[ch], TCR, OVIE));
212         ret = FIELD_DP8(ret, TCR, CMIEA,
213                         FIELD_EX8(tmr->tcr[ch], TCR, CMIEA));
214         ret = FIELD_DP8(ret, TCR, CMIEB,
215                         FIELD_EX8(tmr->tcr[ch], TCR, CMIEB));
216         return ret;
217     case A_TCSR:
218         ret = 0;
219         ret = FIELD_DP8(ret, TCSR, OSA,
220                         FIELD_EX8(tmr->tcsr[ch], TCSR, OSA));
221         ret = FIELD_DP8(ret, TCSR, OSB,
222                         FIELD_EX8(tmr->tcsr[ch], TCSR, OSB));
223         switch (ch) {
224         case 0:
225             ret = FIELD_DP8(ret, TCSR, ADTE,
226                             FIELD_EX8(tmr->tcsr[ch], TCSR, ADTE));
227             break;
228         case 1: /* CH1 ADTE unimplement always 1 */
229             ret = FIELD_DP8(ret, TCSR, ADTE, 1);
230             break;
231         }
232         return ret;
233     case A_TCORA:
234         if (size == 1) {
235             return tmr->tcora[ch];
236         } else if (ch == 0) {
237             return concat_reg(tmr->tcora);
238         }
239         /* fall through */
240     case A_TCORB:
241         if (size == 1) {
242             return tmr->tcorb[ch];
243         } else {
244             return concat_reg(tmr->tcorb);
245         }
246     case A_TCNT:
247         return read_tcnt(tmr, size, ch);
248     case A_TCCR:
249         if (size == 1) {
250             return read_tccr(tmr->tccr[ch]);
251         } else {
252             return read_tccr(tmr->tccr[0]) << 8 | read_tccr(tmr->tccr[1]);
253         }
254     default:
255         qemu_log_mask(LOG_UNIMP, "renesas_tmr: Register 0x%" HWADDR_PRIX
256                                  " not implemented\n",
257                       addr);
258         break;
259     }
260     return UINT64_MAX;
261 }
262 
263 static void tmr_write_count(RTMRState *tmr, int ch, unsigned size,
264                             uint8_t *reg, uint64_t val)
265 {
266     if (size == 1) {
267         reg[ch] = val;
268         update_events(tmr, ch);
269     } else {
270         reg[0] = extract32(val, 8, 8);
271         reg[1] = extract32(val, 0, 8);
272         update_events(tmr, 0);
273         update_events(tmr, 1);
274     }
275 }
276 
277 static void tmr_write(void *opaque, hwaddr addr, uint64_t val, unsigned size)
278 {
279     RTMRState *tmr = opaque;
280     int ch = addr & 1;
281 
282     if (size == 2 && (ch != 0 || addr == A_TCR || addr == A_TCSR)) {
283         qemu_log_mask(LOG_GUEST_ERROR,
284                       "renesas_tmr: Invalid write size 0x%" HWADDR_PRIX "\n",
285                       addr);
286         return;
287     }
288     switch (addr & 0x0e) {
289     case A_TCR:
290         tmr->tcr[ch] = val;
291         break;
292     case A_TCSR:
293         tmr->tcsr[ch] = val;
294         break;
295     case A_TCORA:
296         tmr_write_count(tmr, ch, size, tmr->tcora, val);
297         break;
298     case A_TCORB:
299         tmr_write_count(tmr, ch, size, tmr->tcorb, val);
300         break;
301     case A_TCNT:
302         tmr_write_count(tmr, ch, size, tmr->tcnt, val);
303         break;
304     case A_TCCR:
305         tmr_write_count(tmr, ch, size, tmr->tccr, val);
306         break;
307     default:
308         qemu_log_mask(LOG_UNIMP, "renesas_tmr: Register 0x%" HWADDR_PRIX
309                                  " not implemented\n",
310                       addr);
311         break;
312     }
313 }
314 
315 static const MemoryRegionOps tmr_ops = {
316     .write = tmr_write,
317     .read  = tmr_read,
318     .endianness = DEVICE_LITTLE_ENDIAN,
319     .impl = {
320         .min_access_size = 1,
321         .max_access_size = 2,
322     },
323     .valid = {
324         .min_access_size = 1,
325         .max_access_size = 2,
326     },
327 };
328 
329 static void timer_events(RTMRState *tmr, int ch);
330 
331 static uint16_t issue_event(RTMRState *tmr, int ch, int sz,
332                         uint16_t tcnt, uint16_t tcora, uint16_t tcorb)
333 {
334     uint16_t ret = tcnt;
335 
336     switch (tmr->next[ch]) {
337     case none:
338         break;
339     case cmia:
340         if (tcnt >= tcora) {
341             if (FIELD_EX8(tmr->tcr[ch], TCR, CCLR) == CCLR_A) {
342                 ret = tcnt - tcora;
343             }
344             if (FIELD_EX8(tmr->tcr[ch], TCR, CMIEA)) {
345                 qemu_irq_pulse(tmr->cmia[ch]);
346             }
347             if (sz == 8 && ch == 0 &&
348                 FIELD_EX8(tmr->tccr[1], TCCR, CSS) == CSS_CASCADING) {
349                 tmr->tcnt[1]++;
350                 timer_events(tmr, 1);
351             }
352         }
353         break;
354     case cmib:
355         if (tcnt >= tcorb) {
356             if (FIELD_EX8(tmr->tcr[ch], TCR, CCLR) == CCLR_B) {
357                 ret = tcnt - tcorb;
358             }
359             if (FIELD_EX8(tmr->tcr[ch], TCR, CMIEB)) {
360                 qemu_irq_pulse(tmr->cmib[ch]);
361             }
362         }
363         break;
364     case ovi:
365         if ((tcnt >= (1 << sz)) && FIELD_EX8(tmr->tcr[ch], TCR, OVIE)) {
366             qemu_irq_pulse(tmr->ovi[ch]);
367         }
368         break;
369     default:
370         g_assert_not_reached();
371     }
372     return ret;
373 }
374 
375 static void timer_events(RTMRState *tmr, int ch)
376 {
377     uint16_t tcnt;
378 
379     tmr->tcnt[ch] = read_tcnt(tmr, 1, ch);
380     if (FIELD_EX8(tmr->tccr[0], TCCR, CSS) != CSS_CASCADING) {
381         tmr->tcnt[ch] = issue_event(tmr, ch, 8,
382                                     tmr->tcnt[ch],
383                                     tmr->tcora[ch],
384                                     tmr->tcorb[ch]) & 0xff;
385     } else {
386         if (ch == 1) {
387             return ;
388         }
389         tcnt = issue_event(tmr, ch, 16,
390                            concat_reg(tmr->tcnt),
391                            concat_reg(tmr->tcora),
392                            concat_reg(tmr->tcorb));
393         tmr->tcnt[0] = (tcnt >> 8) & 0xff;
394         tmr->tcnt[1] = tcnt & 0xff;
395     }
396     update_events(tmr, ch);
397 }
398 
399 static void timer_event0(void *opaque)
400 {
401     RTMRState *tmr = opaque;
402 
403     timer_events(tmr, 0);
404 }
405 
406 static void timer_event1(void *opaque)
407 {
408     RTMRState *tmr = opaque;
409 
410     timer_events(tmr, 1);
411 }
412 
413 static void rtmr_reset(DeviceState *dev)
414 {
415     RTMRState *tmr = RTMR(dev);
416     tmr->tcr[0]   = tmr->tcr[1]   = 0x00;
417     tmr->tcsr[0]  = 0x00;
418     tmr->tcsr[1]  = 0x10;
419     tmr->tcnt[0]  = tmr->tcnt[1]  = 0x00;
420     tmr->tcora[0] = tmr->tcora[1] = 0xff;
421     tmr->tcorb[0] = tmr->tcorb[1] = 0xff;
422     tmr->tccr[0]  = tmr->tccr[1]  = 0x00;
423     tmr->next[0]  = tmr->next[1]  = none;
424     tmr->tick = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
425 }
426 
427 static void rtmr_init(Object *obj)
428 {
429     SysBusDevice *d = SYS_BUS_DEVICE(obj);
430     RTMRState *tmr = RTMR(obj);
431     int i;
432 
433     memory_region_init_io(&tmr->memory, OBJECT(tmr), &tmr_ops,
434                           tmr, "renesas-tmr", 0x10);
435     sysbus_init_mmio(d, &tmr->memory);
436 
437     for (i = 0; i < ARRAY_SIZE(tmr->ovi); i++) {
438         sysbus_init_irq(d, &tmr->cmia[i]);
439         sysbus_init_irq(d, &tmr->cmib[i]);
440         sysbus_init_irq(d, &tmr->ovi[i]);
441     }
442     timer_init_ns(&tmr->timer[0], QEMU_CLOCK_VIRTUAL, timer_event0, tmr);
443     timer_init_ns(&tmr->timer[1], QEMU_CLOCK_VIRTUAL, timer_event1, tmr);
444 }
445 
446 static const VMStateDescription vmstate_rtmr = {
447     .name = "rx-tmr",
448     .version_id = 1,
449     .minimum_version_id = 1,
450     .fields = (VMStateField[]) {
451         VMSTATE_INT64(tick, RTMRState),
452         VMSTATE_UINT8_ARRAY(tcnt, RTMRState, TMR_CH),
453         VMSTATE_UINT8_ARRAY(tcora, RTMRState, TMR_CH),
454         VMSTATE_UINT8_ARRAY(tcorb, RTMRState, TMR_CH),
455         VMSTATE_UINT8_ARRAY(tcr, RTMRState, TMR_CH),
456         VMSTATE_UINT8_ARRAY(tccr, RTMRState, TMR_CH),
457         VMSTATE_UINT8_ARRAY(tcor, RTMRState, TMR_CH),
458         VMSTATE_UINT8_ARRAY(tcsr, RTMRState, TMR_CH),
459         VMSTATE_INT64_ARRAY(div_round, RTMRState, TMR_CH),
460         VMSTATE_UINT8_ARRAY(next, RTMRState, TMR_CH),
461         VMSTATE_TIMER_ARRAY(timer, RTMRState, TMR_CH),
462         VMSTATE_END_OF_LIST()
463     }
464 };
465 
466 static Property rtmr_properties[] = {
467     DEFINE_PROP_UINT64("input-freq", RTMRState, input_freq, 0),
468     DEFINE_PROP_END_OF_LIST(),
469 };
470 
471 static void rtmr_class_init(ObjectClass *klass, void *data)
472 {
473     DeviceClass *dc = DEVICE_CLASS(klass);
474 
475     dc->vmsd = &vmstate_rtmr;
476     dc->reset = rtmr_reset;
477     device_class_set_props(dc, rtmr_properties);
478 }
479 
480 static const TypeInfo rtmr_info = {
481     .name = TYPE_RENESAS_TMR,
482     .parent = TYPE_SYS_BUS_DEVICE,
483     .instance_size = sizeof(RTMRState),
484     .instance_init = rtmr_init,
485     .class_init = rtmr_class_init,
486 };
487 
488 static void rtmr_register_types(void)
489 {
490     type_register_static(&rtmr_info);
491 }
492 
493 type_init(rtmr_register_types)
494