1/*
2 * Xilinx Zynq cadence TTC model
3 *
4 * Copyright (c) 2011 Xilinx Inc.
5 * Copyright (c) 2012 Peter A.G. Crosthwaite (peter.crosthwaite@petalogix.com)
6 * Copyright (c) 2012 PetaLogix Pty Ltd.
7 * Written By Haibing Ma
8 * M. Habib
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
14 *
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, see <http://www.gnu.org/licenses/>.
17 */
18
19#include "qemu/osdep.h"
20#include "hw/irq.h"
21#include "hw/sysbus.h"
22#include "migration/vmstate.h"
23#include "qemu/module.h"
24#include "qemu/timer.h"
25
26#ifdef CADENCE_TTC_ERR_DEBUG
27#define DB_PRINT(...) do { \
28 fprintf(stderr, ": %s: ", __func__); \
29 fprintf(stderr, ## __VA_ARGS__); \
30 } while (0)
31#else
32 #define DB_PRINT(...)
33#endif
34
35#define COUNTER_INTR_IV 0x00000001
36#define COUNTER_INTR_M1 0x00000002
37#define COUNTER_INTR_M2 0x00000004
38#define COUNTER_INTR_M3 0x00000008
39#define COUNTER_INTR_OV 0x00000010
40#define COUNTER_INTR_EV 0x00000020
41
42#define COUNTER_CTRL_DIS 0x00000001
43#define COUNTER_CTRL_INT 0x00000002
44#define COUNTER_CTRL_DEC 0x00000004
45#define COUNTER_CTRL_MATCH 0x00000008
46#define COUNTER_CTRL_RST 0x00000010
47
48#define CLOCK_CTRL_PS_EN 0x00000001
49#define CLOCK_CTRL_PS_V 0x0000001e
50
51typedef struct {
52 QEMUTimer *timer;
53 int freq;
54
55 uint32_t reg_clock;
56 uint32_t reg_count;
57 uint32_t reg_value;
58 uint16_t reg_interval;
59 uint16_t reg_match[3];
60 uint32_t reg_intr;
61 uint32_t reg_intr_en;
62 uint32_t reg_event_ctrl;
63 uint32_t reg_event;
64
65 uint64_t cpu_time;
66 unsigned int cpu_time_valid;
67
68 qemu_irq irq;
69} CadenceTimerState;
70
71#define TYPE_CADENCE_TTC "cadence_ttc"
72#define CADENCE_TTC(obj) \
73 OBJECT_CHECK(CadenceTTCState, (obj), TYPE_CADENCE_TTC)
74
75typedef struct CadenceTTCState {
76 SysBusDevice parent_obj;
77
78 MemoryRegion iomem;
79 CadenceTimerState timer[3];
80} CadenceTTCState;
81
82static void cadence_timer_update(CadenceTimerState *s)
83{
84 qemu_set_irq(s->irq, !!(s->reg_intr & s->reg_intr_en));
85}
86
87static CadenceTimerState *cadence_timer_from_addr(void *opaque,
88 hwaddr offset)
89{
90 unsigned int index;
91 CadenceTTCState *s = (CadenceTTCState *)opaque;
92
93 index = (offset >> 2) % 3;
94
95 return &s->timer[index];
96}
97
98static uint64_t cadence_timer_get_ns(CadenceTimerState *s, uint64_t timer_steps)
99{
100 /* timer_steps has max value of 0x100000000. double check it
101 * (or overflow can happen below) */
102 assert(timer_steps <= 1ULL << 32);
103
104 uint64_t r = timer_steps * 1000000000ULL;
105 if (s->reg_clock & CLOCK_CTRL_PS_EN) {
106 r >>= 16 - (((s->reg_clock & CLOCK_CTRL_PS_V) >> 1) + 1);
107 } else {
108 r >>= 16;
109 }
110 r /= (uint64_t)s->freq;
111 return r;
112}
113
114static uint64_t cadence_timer_get_steps(CadenceTimerState *s, uint64_t ns)
115{
116 uint64_t to_divide = 1000000000ULL;
117
118 uint64_t r = ns;
119 /* for very large intervals (> 8s) do some division first to stop
120 * overflow (costs some prescision) */
121 while (r >= 8ULL << 30 && to_divide > 1) {
122 r /= 1000;
123 to_divide /= 1000;
124 }
125 r <<= 16;
126 /* keep early-dividing as needed */
127 while (r >= 8ULL << 30 && to_divide > 1) {
128 r /= 1000;
129 to_divide /= 1000;
130 }
131 r *= (uint64_t)s->freq;
132 if (s->reg_clock & CLOCK_CTRL_PS_EN) {
133 r /= 1 << (((s->reg_clock & CLOCK_CTRL_PS_V) >> 1) + 1);
134 }
135
136 r /= to_divide;
137 return r;
138}
139
140/* determine if x is in between a and b, exclusive of a, inclusive of b */
141
142static inline int64_t is_between(int64_t x, int64_t a, int64_t b)
143{
144 if (a < b) {
145 return x > a && x <= b;
146 }
147 return x < a && x >= b;
148}
149
150static void cadence_timer_run(CadenceTimerState *s)
151{
152 int i;
153 int64_t event_interval, next_value;
154
155 assert(s->cpu_time_valid); /* cadence_timer_sync must be called first */
156
157 if (s->reg_count & COUNTER_CTRL_DIS) {
158 s->cpu_time_valid = 0;
159 return;
160 }
161
162 { /* figure out what's going to happen next (rollover or match) */
163 int64_t interval = (uint64_t)((s->reg_count & COUNTER_CTRL_INT) ?
164 (int64_t)s->reg_interval + 1 : 0x10000ULL) << 16;
165 next_value = (s->reg_count & COUNTER_CTRL_DEC) ? -1ULL : interval;
166 for (i = 0; i < 3; ++i) {
167 int64_t cand = (uint64_t)s->reg_match[i] << 16;
168 if (is_between(cand, (uint64_t)s->reg_value, next_value)) {
169 next_value = cand;
170 }
171 }
172 }
173 DB_PRINT("next timer event value: %09llx\n",
174 (unsigned long long)next_value);
175
176 event_interval = next_value - (int64_t)s->reg_value;
177 event_interval = (event_interval < 0) ? -event_interval : event_interval;
178
179 timer_mod(s->timer, s->cpu_time +
180 cadence_timer_get_ns(s, event_interval));
181}
182
183static void cadence_timer_sync(CadenceTimerState *s)
184{
185 int i;
186 int64_t r, x;
187 int64_t interval = ((s->reg_count & COUNTER_CTRL_INT) ?
188 (int64_t)s->reg_interval + 1 : 0x10000ULL) << 16;
189 uint64_t old_time = s->cpu_time;
190
191 s->cpu_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
192 DB_PRINT("cpu time: %lld ns\n", (long long)old_time);
193
194 if (!s->cpu_time_valid || old_time == s->cpu_time) {
195 s->cpu_time_valid = 1;
196 return;
197 }
198
199 r = (int64_t)cadence_timer_get_steps(s, s->cpu_time - old_time);
200 x = (int64_t)s->reg_value + ((s->reg_count & COUNTER_CTRL_DEC) ? -r : r);
201
202 for (i = 0; i < 3; ++i) {
203 int64_t m = (int64_t)s->reg_match[i] << 16;
204 if (m > interval) {
205 continue;
206 }
207 /* check to see if match event has occurred. check m +/- interval
208 * to account for match events in wrap around cases */
209 if (is_between(m, s->reg_value, x) ||
210 is_between(m + interval, s->reg_value, x) ||
211 is_between(m - interval, s->reg_value, x)) {
212 s->reg_intr |= (2 << i);
213 }
214 }
215 if ((x < 0) || (x >= interval)) {
216 s->reg_intr |= (s->reg_count & COUNTER_CTRL_INT) ?
217 COUNTER_INTR_IV : COUNTER_INTR_OV;
218 }
219 while (x < 0) {
220 x += interval;
221 }
222 s->reg_value = (uint32_t)(x % interval);
223 cadence_timer_update(s);
224}
225
226static void cadence_timer_tick(void *opaque)
227{
228 CadenceTimerState *s = opaque;
229
230 DB_PRINT("\n");
231 cadence_timer_sync(s);
232 cadence_timer_run(s);
233}
234
235static uint32_t cadence_ttc_read_imp(void *opaque, hwaddr offset)
236{
237 CadenceTimerState *s = cadence_timer_from_addr(opaque, offset);
238 uint32_t value;
239
240 cadence_timer_sync(s);
241 cadence_timer_run(s);
242
243 switch (offset) {
244 case 0x00: /* clock control */
245 case 0x04:
246 case 0x08:
247 return s->reg_clock;
248
249 case 0x0c: /* counter control */
250 case 0x10:
251 case 0x14:
252 return s->reg_count;
253
254 case 0x18: /* counter value */
255 case 0x1c:
256 case 0x20:
257 return (uint16_t)(s->reg_value >> 16);
258
259 case 0x24: /* reg_interval counter */
260 case 0x28:
261 case 0x2c:
262 return s->reg_interval;
263
264 case 0x30: /* match 1 counter */
265 case 0x34:
266 case 0x38:
267 return s->reg_match[0];
268
269 case 0x3c: /* match 2 counter */
270 case 0x40:
271 case 0x44:
272 return s->reg_match[1];
273
274 case 0x48: /* match 3 counter */
275 case 0x4c:
276 case 0x50:
277 return s->reg_match[2];
278
279 case 0x54: /* interrupt register */
280 case 0x58:
281 case 0x5c:
282 /* cleared after read */
283 value = s->reg_intr;
284 s->reg_intr = 0;
285 cadence_timer_update(s);
286 return value;
287
288 case 0x60: /* interrupt enable */
289 case 0x64:
290 case 0x68:
291 return s->reg_intr_en;
292
293 case 0x6c:
294 case 0x70:
295 case 0x74:
296 return s->reg_event_ctrl;
297
298 case 0x78:
299 case 0x7c:
300 case 0x80:
301 return s->reg_event;
302
303 default:
304 return 0;
305 }
306}
307
308static uint64_t cadence_ttc_read(void *opaque, hwaddr offset,
309 unsigned size)
310{
311 uint32_t ret = cadence_ttc_read_imp(opaque, offset);
312
313 DB_PRINT("addr: %08x data: %08x\n", (unsigned)offset, (unsigned)ret);
314 return ret;
315}
316
317static void cadence_ttc_write(void *opaque, hwaddr offset,
318 uint64_t value, unsigned size)
319{
320 CadenceTimerState *s = cadence_timer_from_addr(opaque, offset);
321
322 DB_PRINT("addr: %08x data %08x\n", (unsigned)offset, (unsigned)value);
323
324 cadence_timer_sync(s);
325
326 switch (offset) {
327 case 0x00: /* clock control */
328 case 0x04:
329 case 0x08:
330 s->reg_clock = value & 0x3F;
331 break;
332
333 case 0x0c: /* counter control */
334 case 0x10:
335 case 0x14:
336 if (value & COUNTER_CTRL_RST) {
337 s->reg_value = 0;
338 }
339 s->reg_count = value & 0x3f & ~COUNTER_CTRL_RST;
340 break;
341
342 case 0x24: /* interval register */
343 case 0x28:
344 case 0x2c:
345 s->reg_interval = value & 0xffff;
346 break;
347
348 case 0x30: /* match register */
349 case 0x34:
350 case 0x38:
351 s->reg_match[0] = value & 0xffff;
352 break;
353
354 case 0x3c: /* match register */
355 case 0x40:
356 case 0x44:
357 s->reg_match[1] = value & 0xffff;
358 break;
359
360 case 0x48: /* match register */
361 case 0x4c:
362 case 0x50:
363 s->reg_match[2] = value & 0xffff;
364 break;
365
366 case 0x54: /* interrupt register */
367 case 0x58:
368 case 0x5c:
369 break;
370
371 case 0x60: /* interrupt enable */
372 case 0x64:
373 case 0x68:
374 s->reg_intr_en = value & 0x3f;
375 break;
376
377 case 0x6c: /* event control */
378 case 0x70:
379 case 0x74:
380 s->reg_event_ctrl = value & 0x07;
381 break;
382
383 default:
384 return;
385 }
386
387 cadence_timer_run(s);
388 cadence_timer_update(s);
389}
390
391static const MemoryRegionOps cadence_ttc_ops = {
392 .read = cadence_ttc_read,
393 .write = cadence_ttc_write,
394 .endianness = DEVICE_NATIVE_ENDIAN,
395};
396
397static void cadence_timer_reset(CadenceTimerState *s)
398{
399 s->reg_count = 0x21;
400}
401
402static void cadence_timer_init(uint32_t freq, CadenceTimerState *s)
403{
404 memset(s, 0, sizeof(CadenceTimerState));
405 s->freq = freq;
406
407 cadence_timer_reset(s);
408
409 s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, cadence_timer_tick, s);
410}
411
412static void cadence_ttc_init(Object *obj)
413{
414 CadenceTTCState *s = CADENCE_TTC(obj);
415 int i;
416
417 for (i = 0; i < 3; ++i) {
418 cadence_timer_init(133000000, &s->timer[i]);
419 sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->timer[i].irq);
420 }
421
422 memory_region_init_io(&s->iomem, obj, &cadence_ttc_ops, s,
423 "timer", 0x1000);
424 sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->iomem);
425}
426
427static int cadence_timer_pre_save(void *opaque)
428{
429 cadence_timer_sync((CadenceTimerState *)opaque);
430
431 return 0;
432}
433
434static int cadence_timer_post_load(void *opaque, int version_id)
435{
436 CadenceTimerState *s = opaque;
437
438 s->cpu_time_valid = 0;
439 cadence_timer_sync(s);
440 cadence_timer_run(s);
441 cadence_timer_update(s);
442 return 0;
443}
444
445static const VMStateDescription vmstate_cadence_timer = {
446 .name = "cadence_timer",
447 .version_id = 1,
448 .minimum_version_id = 1,
449 .pre_save = cadence_timer_pre_save,
450 .post_load = cadence_timer_post_load,
451 .fields = (VMStateField[]) {
452 VMSTATE_UINT32(reg_clock, CadenceTimerState),
453 VMSTATE_UINT32(reg_count, CadenceTimerState),
454 VMSTATE_UINT32(reg_value, CadenceTimerState),
455 VMSTATE_UINT16(reg_interval, CadenceTimerState),
456 VMSTATE_UINT16_ARRAY(reg_match, CadenceTimerState, 3),
457 VMSTATE_UINT32(reg_intr, CadenceTimerState),
458 VMSTATE_UINT32(reg_intr_en, CadenceTimerState),
459 VMSTATE_UINT32(reg_event_ctrl, CadenceTimerState),
460 VMSTATE_UINT32(reg_event, CadenceTimerState),
461 VMSTATE_END_OF_LIST()
462 }
463};
464
465static const VMStateDescription vmstate_cadence_ttc = {
466 .name = "cadence_TTC",
467 .version_id = 1,
468 .minimum_version_id = 1,
469 .fields = (VMStateField[]) {
470 VMSTATE_STRUCT_ARRAY(timer, CadenceTTCState, 3, 0,
471 vmstate_cadence_timer,
472 CadenceTimerState),
473 VMSTATE_END_OF_LIST()
474 }
475};
476
477static void cadence_ttc_class_init(ObjectClass *klass, void *data)
478{
479 DeviceClass *dc = DEVICE_CLASS(klass);
480
481 dc->vmsd = &vmstate_cadence_ttc;
482}
483
484static const TypeInfo cadence_ttc_info = {
485 .name = TYPE_CADENCE_TTC,
486 .parent = TYPE_SYS_BUS_DEVICE,
487 .instance_size = sizeof(CadenceTTCState),
488 .instance_init = cadence_ttc_init,
489 .class_init = cadence_ttc_class_init,
490};
491
492static void cadence_ttc_register_types(void)
493{
494 type_register_static(&cadence_ttc_info);
495}
496
497type_init(cadence_ttc_register_types)
498