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1 | /* |
2 | * ARM CMSDK APB dual-timer emulation | |
3 | * | |
4 | * Copyright (c) 2018 Linaro Limited | |
5 | * Written by Peter Maydell | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 or | |
9 | * (at your option) any later version. | |
10 | */ | |
11 | ||
12 | /* | |
13 | * This is a model of the "APB dual-input timer" which is part of the Cortex-M | |
14 | * System Design Kit (CMSDK) and documented in the Cortex-M System | |
15 | * Design Kit Technical Reference Manual (ARM DDI0479C): | |
16 | * https://developer.arm.com/products/system-design/system-design-kits/cortex-m-system-design-kit | |
17 | */ | |
18 | ||
19 | #include "qemu/osdep.h" | |
20 | #include "qemu/log.h" | |
21 | #include "trace.h" | |
22 | #include "qapi/error.h" | |
23 | #include "qemu/main-loop.h" | |
24 | #include "hw/sysbus.h" | |
25 | #include "hw/registerfields.h" | |
26 | #include "hw/timer/cmsdk-apb-dualtimer.h" | |
27 | ||
28 | REG32(TIMER1LOAD, 0x0) | |
29 | REG32(TIMER1VALUE, 0x4) | |
30 | REG32(TIMER1CONTROL, 0x8) | |
31 | FIELD(CONTROL, ONESHOT, 0, 1) | |
32 | FIELD(CONTROL, SIZE, 1, 1) | |
33 | FIELD(CONTROL, PRESCALE, 2, 2) | |
34 | FIELD(CONTROL, INTEN, 5, 1) | |
35 | FIELD(CONTROL, MODE, 6, 1) | |
36 | FIELD(CONTROL, ENABLE, 7, 1) | |
37 | #define R_CONTROL_VALID_MASK (R_CONTROL_ONESHOT_MASK | R_CONTROL_SIZE_MASK | \ | |
38 | R_CONTROL_PRESCALE_MASK | R_CONTROL_INTEN_MASK | \ | |
39 | R_CONTROL_MODE_MASK | R_CONTROL_ENABLE_MASK) | |
40 | REG32(TIMER1INTCLR, 0xc) | |
41 | REG32(TIMER1RIS, 0x10) | |
42 | REG32(TIMER1MIS, 0x14) | |
43 | REG32(TIMER1BGLOAD, 0x18) | |
44 | REG32(TIMER2LOAD, 0x20) | |
45 | REG32(TIMER2VALUE, 0x24) | |
46 | REG32(TIMER2CONTROL, 0x28) | |
47 | REG32(TIMER2INTCLR, 0x2c) | |
48 | REG32(TIMER2RIS, 0x30) | |
49 | REG32(TIMER2MIS, 0x34) | |
50 | REG32(TIMER2BGLOAD, 0x38) | |
51 | REG32(TIMERITCR, 0xf00) | |
52 | FIELD(TIMERITCR, ENABLE, 0, 1) | |
53 | #define R_TIMERITCR_VALID_MASK R_TIMERITCR_ENABLE_MASK | |
54 | REG32(TIMERITOP, 0xf04) | |
55 | FIELD(TIMERITOP, TIMINT1, 0, 1) | |
56 | FIELD(TIMERITOP, TIMINT2, 1, 1) | |
57 | #define R_TIMERITOP_VALID_MASK (R_TIMERITOP_TIMINT1_MASK | \ | |
58 | R_TIMERITOP_TIMINT2_MASK) | |
59 | REG32(PID4, 0xfd0) | |
60 | REG32(PID5, 0xfd4) | |
61 | REG32(PID6, 0xfd8) | |
62 | REG32(PID7, 0xfdc) | |
63 | REG32(PID0, 0xfe0) | |
64 | REG32(PID1, 0xfe4) | |
65 | REG32(PID2, 0xfe8) | |
66 | REG32(PID3, 0xfec) | |
67 | REG32(CID0, 0xff0) | |
68 | REG32(CID1, 0xff4) | |
69 | REG32(CID2, 0xff8) | |
70 | REG32(CID3, 0xffc) | |
71 | ||
72 | /* PID/CID values */ | |
73 | static const int timer_id[] = { | |
74 | 0x04, 0x00, 0x00, 0x00, /* PID4..PID7 */ | |
75 | 0x23, 0xb8, 0x1b, 0x00, /* PID0..PID3 */ | |
76 | 0x0d, 0xf0, 0x05, 0xb1, /* CID0..CID3 */ | |
77 | }; | |
78 | ||
79 | static bool cmsdk_dualtimermod_intstatus(CMSDKAPBDualTimerModule *m) | |
80 | { | |
81 | /* Return masked interrupt status for the timer module */ | |
82 | return m->intstatus && (m->control & R_CONTROL_INTEN_MASK); | |
83 | } | |
84 | ||
85 | static void cmsdk_apb_dualtimer_update(CMSDKAPBDualTimer *s) | |
86 | { | |
87 | bool timint1, timint2, timintc; | |
88 | ||
89 | if (s->timeritcr) { | |
90 | /* Integration test mode: outputs driven directly from TIMERITOP bits */ | |
91 | timint1 = s->timeritop & R_TIMERITOP_TIMINT1_MASK; | |
92 | timint2 = s->timeritop & R_TIMERITOP_TIMINT2_MASK; | |
93 | } else { | |
94 | timint1 = cmsdk_dualtimermod_intstatus(&s->timermod[0]); | |
95 | timint2 = cmsdk_dualtimermod_intstatus(&s->timermod[1]); | |
96 | } | |
97 | ||
98 | timintc = timint1 || timint2; | |
99 | ||
100 | qemu_set_irq(s->timermod[0].timerint, timint1); | |
101 | qemu_set_irq(s->timermod[1].timerint, timint2); | |
102 | qemu_set_irq(s->timerintc, timintc); | |
103 | } | |
104 | ||
105 | static void cmsdk_dualtimermod_write_control(CMSDKAPBDualTimerModule *m, | |
106 | uint32_t newctrl) | |
107 | { | |
108 | /* Handle a write to the CONTROL register */ | |
109 | uint32_t changed; | |
110 | ||
111 | newctrl &= R_CONTROL_VALID_MASK; | |
112 | ||
113 | changed = m->control ^ newctrl; | |
114 | ||
115 | if (changed & ~newctrl & R_CONTROL_ENABLE_MASK) { | |
116 | /* ENABLE cleared, stop timer before any further changes */ | |
117 | ptimer_stop(m->timer); | |
118 | } | |
119 | ||
120 | if (changed & R_CONTROL_PRESCALE_MASK) { | |
121 | int divisor; | |
122 | ||
123 | switch (FIELD_EX32(newctrl, CONTROL, PRESCALE)) { | |
124 | case 0: | |
125 | divisor = 1; | |
126 | break; | |
127 | case 1: | |
128 | divisor = 16; | |
129 | break; | |
130 | case 2: | |
131 | divisor = 256; | |
132 | break; | |
133 | case 3: | |
134 | /* UNDEFINED; complain, and arbitrarily treat like 2 */ | |
135 | qemu_log_mask(LOG_GUEST_ERROR, | |
136 | "CMSDK APB dual-timer: CONTROL.PRESCALE==0b11" | |
137 | " is undefined behaviour\n"); | |
138 | divisor = 256; | |
139 | break; | |
140 | default: | |
141 | g_assert_not_reached(); | |
142 | } | |
143 | ptimer_set_freq(m->timer, m->parent->pclk_frq / divisor); | |
144 | } | |
145 | ||
146 | if (changed & R_CONTROL_MODE_MASK) { | |
147 | uint32_t load; | |
148 | if (newctrl & R_CONTROL_MODE_MASK) { | |
149 | /* Periodic: the limit is the LOAD register value */ | |
150 | load = m->load; | |
151 | } else { | |
152 | /* Free-running: counter wraps around */ | |
153 | load = ptimer_get_limit(m->timer); | |
154 | if (!(m->control & R_CONTROL_SIZE_MASK)) { | |
155 | load = deposit32(m->load, 0, 16, load); | |
156 | } | |
157 | m->load = load; | |
158 | load = 0xffffffff; | |
159 | } | |
160 | if (!(m->control & R_CONTROL_SIZE_MASK)) { | |
161 | load &= 0xffff; | |
162 | } | |
163 | ptimer_set_limit(m->timer, load, 0); | |
164 | } | |
165 | ||
166 | if (changed & R_CONTROL_SIZE_MASK) { | |
167 | /* Timer switched between 16 and 32 bit count */ | |
168 | uint32_t value, load; | |
169 | ||
170 | value = ptimer_get_count(m->timer); | |
171 | load = ptimer_get_limit(m->timer); | |
172 | if (newctrl & R_CONTROL_SIZE_MASK) { | |
173 | /* 16 -> 32, top half of VALUE is in struct field */ | |
174 | value = deposit32(m->value, 0, 16, value); | |
175 | } else { | |
176 | /* 32 -> 16: save top half to struct field and truncate */ | |
177 | m->value = value; | |
178 | value &= 0xffff; | |
179 | } | |
180 | ||
181 | if (newctrl & R_CONTROL_MODE_MASK) { | |
182 | /* Periodic, timer limit has LOAD value */ | |
183 | if (newctrl & R_CONTROL_SIZE_MASK) { | |
184 | load = deposit32(m->load, 0, 16, load); | |
185 | } else { | |
186 | m->load = load; | |
187 | load &= 0xffff; | |
188 | } | |
189 | } else { | |
190 | /* Free-running, timer limit is set to give wraparound */ | |
191 | if (newctrl & R_CONTROL_SIZE_MASK) { | |
192 | load = 0xffffffff; | |
193 | } else { | |
194 | load = 0xffff; | |
195 | } | |
196 | } | |
197 | ptimer_set_count(m->timer, value); | |
198 | ptimer_set_limit(m->timer, load, 0); | |
199 | } | |
200 | ||
201 | if (newctrl & R_CONTROL_ENABLE_MASK) { | |
202 | /* | |
203 | * ENABLE is set; start the timer after all other changes. | |
204 | * We start it even if the ENABLE bit didn't actually change, | |
205 | * in case the timer was an expired one-shot timer that has | |
206 | * now been changed into a free-running or periodic timer. | |
207 | */ | |
208 | ptimer_run(m->timer, !!(newctrl & R_CONTROL_ONESHOT_MASK)); | |
209 | } | |
210 | ||
211 | m->control = newctrl; | |
212 | } | |
213 | ||
214 | static uint64_t cmsdk_apb_dualtimer_read(void *opaque, hwaddr offset, | |
215 | unsigned size) | |
216 | { | |
217 | CMSDKAPBDualTimer *s = CMSDK_APB_DUALTIMER(opaque); | |
218 | uint64_t r; | |
219 | ||
220 | if (offset >= A_TIMERITCR) { | |
221 | switch (offset) { | |
222 | case A_TIMERITCR: | |
223 | r = s->timeritcr; | |
224 | break; | |
225 | case A_PID4 ... A_CID3: | |
226 | r = timer_id[(offset - A_PID4) / 4]; | |
227 | break; | |
228 | default: | |
229 | bad_offset: | |
230 | qemu_log_mask(LOG_GUEST_ERROR, | |
231 | "CMSDK APB dual-timer read: bad offset %x\n", | |
232 | (int) offset); | |
233 | r = 0; | |
234 | break; | |
235 | } | |
236 | } else { | |
237 | int timer = offset >> 5; | |
238 | CMSDKAPBDualTimerModule *m; | |
239 | ||
240 | if (timer >= ARRAY_SIZE(s->timermod)) { | |
241 | goto bad_offset; | |
242 | } | |
243 | ||
244 | m = &s->timermod[timer]; | |
245 | ||
246 | switch (offset & 0x1F) { | |
247 | case A_TIMER1LOAD: | |
248 | case A_TIMER1BGLOAD: | |
249 | if (m->control & R_CONTROL_MODE_MASK) { | |
250 | /* | |
251 | * Periodic: the ptimer limit is the LOAD register value, (or | |
252 | * just the low 16 bits of it if the timer is in 16-bit mode) | |
253 | */ | |
254 | r = ptimer_get_limit(m->timer); | |
255 | if (!(m->control & R_CONTROL_SIZE_MASK)) { | |
256 | r = deposit32(m->load, 0, 16, r); | |
257 | } | |
258 | } else { | |
259 | /* Free-running: LOAD register value is just in m->load */ | |
260 | r = m->load; | |
261 | } | |
262 | break; | |
263 | case A_TIMER1VALUE: | |
264 | r = ptimer_get_count(m->timer); | |
265 | if (!(m->control & R_CONTROL_SIZE_MASK)) { | |
266 | r = deposit32(m->value, 0, 16, r); | |
267 | } | |
268 | break; | |
269 | case A_TIMER1CONTROL: | |
270 | r = m->control; | |
271 | break; | |
272 | case A_TIMER1RIS: | |
273 | r = m->intstatus; | |
274 | break; | |
275 | case A_TIMER1MIS: | |
276 | r = cmsdk_dualtimermod_intstatus(m); | |
277 | break; | |
278 | default: | |
279 | goto bad_offset; | |
280 | } | |
281 | } | |
282 | ||
283 | trace_cmsdk_apb_dualtimer_read(offset, r, size); | |
284 | return r; | |
285 | } | |
286 | ||
287 | static void cmsdk_apb_dualtimer_write(void *opaque, hwaddr offset, | |
288 | uint64_t value, unsigned size) | |
289 | { | |
290 | CMSDKAPBDualTimer *s = CMSDK_APB_DUALTIMER(opaque); | |
291 | ||
292 | trace_cmsdk_apb_dualtimer_write(offset, value, size); | |
293 | ||
294 | if (offset >= A_TIMERITCR) { | |
295 | switch (offset) { | |
296 | case A_TIMERITCR: | |
297 | s->timeritcr = value & R_TIMERITCR_VALID_MASK; | |
298 | cmsdk_apb_dualtimer_update(s); | |
3e1dd459 | 299 | break; |
4f4c6206 PM |
300 | case A_TIMERITOP: |
301 | s->timeritop = value & R_TIMERITOP_VALID_MASK; | |
302 | cmsdk_apb_dualtimer_update(s); | |
3e1dd459 | 303 | break; |
4f4c6206 PM |
304 | default: |
305 | bad_offset: | |
306 | qemu_log_mask(LOG_GUEST_ERROR, | |
307 | "CMSDK APB dual-timer write: bad offset %x\n", | |
308 | (int) offset); | |
309 | break; | |
310 | } | |
311 | } else { | |
312 | int timer = offset >> 5; | |
313 | CMSDKAPBDualTimerModule *m; | |
314 | ||
315 | if (timer >= ARRAY_SIZE(s->timermod)) { | |
316 | goto bad_offset; | |
317 | } | |
318 | ||
319 | m = &s->timermod[timer]; | |
320 | ||
321 | switch (offset & 0x1F) { | |
322 | case A_TIMER1LOAD: | |
323 | /* Set the limit, and immediately reload the count from it */ | |
324 | m->load = value; | |
325 | m->value = value; | |
326 | if (!(m->control & R_CONTROL_SIZE_MASK)) { | |
327 | value &= 0xffff; | |
328 | } | |
329 | if (!(m->control & R_CONTROL_MODE_MASK)) { | |
330 | /* | |
331 | * In free-running mode this won't set the limit but will | |
332 | * still change the current count value. | |
333 | */ | |
334 | ptimer_set_count(m->timer, value); | |
335 | } else { | |
336 | if (!value) { | |
337 | ptimer_stop(m->timer); | |
338 | } | |
339 | ptimer_set_limit(m->timer, value, 1); | |
340 | if (value && (m->control & R_CONTROL_ENABLE_MASK)) { | |
341 | /* Force possibly-expired oneshot timer to restart */ | |
342 | ptimer_run(m->timer, 1); | |
343 | } | |
344 | } | |
345 | break; | |
346 | case A_TIMER1BGLOAD: | |
347 | /* Set the limit, but not the current count */ | |
348 | m->load = value; | |
349 | if (!(m->control & R_CONTROL_MODE_MASK)) { | |
350 | /* In free-running mode there is no limit */ | |
351 | break; | |
352 | } | |
353 | if (!(m->control & R_CONTROL_SIZE_MASK)) { | |
354 | value &= 0xffff; | |
355 | } | |
356 | ptimer_set_limit(m->timer, value, 0); | |
357 | break; | |
358 | case A_TIMER1CONTROL: | |
359 | cmsdk_dualtimermod_write_control(m, value); | |
360 | cmsdk_apb_dualtimer_update(s); | |
361 | break; | |
362 | case A_TIMER1INTCLR: | |
363 | m->intstatus = 0; | |
364 | cmsdk_apb_dualtimer_update(s); | |
365 | break; | |
366 | default: | |
367 | goto bad_offset; | |
368 | } | |
369 | } | |
370 | } | |
371 | ||
372 | static const MemoryRegionOps cmsdk_apb_dualtimer_ops = { | |
373 | .read = cmsdk_apb_dualtimer_read, | |
374 | .write = cmsdk_apb_dualtimer_write, | |
375 | .endianness = DEVICE_LITTLE_ENDIAN, | |
376 | /* byte/halfword accesses are just zero-padded on reads and writes */ | |
377 | .impl.min_access_size = 4, | |
378 | .impl.max_access_size = 4, | |
379 | .valid.min_access_size = 1, | |
380 | .valid.max_access_size = 4, | |
381 | }; | |
382 | ||
383 | static void cmsdk_dualtimermod_tick(void *opaque) | |
384 | { | |
385 | CMSDKAPBDualTimerModule *m = opaque; | |
386 | ||
387 | m->intstatus = 1; | |
388 | cmsdk_apb_dualtimer_update(m->parent); | |
389 | } | |
390 | ||
391 | static void cmsdk_dualtimermod_reset(CMSDKAPBDualTimerModule *m) | |
392 | { | |
393 | m->control = R_CONTROL_INTEN_MASK; | |
394 | m->intstatus = 0; | |
395 | m->load = 0; | |
396 | m->value = 0xffffffff; | |
397 | ptimer_stop(m->timer); | |
398 | /* | |
399 | * We start in free-running mode, with VALUE at 0xffffffff, and | |
400 | * in 16-bit counter mode. This means that the ptimer count and | |
401 | * limit must both be set to 0xffff, so we wrap at 16 bits. | |
402 | */ | |
403 | ptimer_set_limit(m->timer, 0xffff, 1); | |
404 | ptimer_set_freq(m->timer, m->parent->pclk_frq); | |
405 | } | |
406 | ||
407 | static void cmsdk_apb_dualtimer_reset(DeviceState *dev) | |
408 | { | |
409 | CMSDKAPBDualTimer *s = CMSDK_APB_DUALTIMER(dev); | |
410 | int i; | |
411 | ||
412 | trace_cmsdk_apb_dualtimer_reset(); | |
413 | ||
414 | for (i = 0; i < ARRAY_SIZE(s->timermod); i++) { | |
415 | cmsdk_dualtimermod_reset(&s->timermod[i]); | |
416 | } | |
417 | s->timeritcr = 0; | |
418 | s->timeritop = 0; | |
419 | } | |
420 | ||
421 | static void cmsdk_apb_dualtimer_init(Object *obj) | |
422 | { | |
423 | SysBusDevice *sbd = SYS_BUS_DEVICE(obj); | |
424 | CMSDKAPBDualTimer *s = CMSDK_APB_DUALTIMER(obj); | |
425 | int i; | |
426 | ||
427 | memory_region_init_io(&s->iomem, obj, &cmsdk_apb_dualtimer_ops, | |
428 | s, "cmsdk-apb-dualtimer", 0x1000); | |
429 | sysbus_init_mmio(sbd, &s->iomem); | |
430 | sysbus_init_irq(sbd, &s->timerintc); | |
431 | ||
432 | for (i = 0; i < ARRAY_SIZE(s->timermod); i++) { | |
433 | sysbus_init_irq(sbd, &s->timermod[i].timerint); | |
434 | } | |
435 | } | |
436 | ||
437 | static void cmsdk_apb_dualtimer_realize(DeviceState *dev, Error **errp) | |
438 | { | |
439 | CMSDKAPBDualTimer *s = CMSDK_APB_DUALTIMER(dev); | |
440 | int i; | |
441 | ||
442 | if (s->pclk_frq == 0) { | |
443 | error_setg(errp, "CMSDK APB timer: pclk-frq property must be set"); | |
444 | return; | |
445 | } | |
446 | ||
447 | for (i = 0; i < ARRAY_SIZE(s->timermod); i++) { | |
448 | CMSDKAPBDualTimerModule *m = &s->timermod[i]; | |
449 | QEMUBH *bh = qemu_bh_new(cmsdk_dualtimermod_tick, m); | |
450 | ||
451 | m->parent = s; | |
452 | m->timer = ptimer_init(bh, | |
453 | PTIMER_POLICY_WRAP_AFTER_ONE_PERIOD | | |
454 | PTIMER_POLICY_TRIGGER_ONLY_ON_DECREMENT | | |
455 | PTIMER_POLICY_NO_IMMEDIATE_RELOAD | | |
456 | PTIMER_POLICY_NO_COUNTER_ROUND_DOWN); | |
457 | } | |
458 | } | |
459 | ||
460 | static const VMStateDescription cmsdk_dualtimermod_vmstate = { | |
461 | .name = "cmsdk-apb-dualtimer-module", | |
462 | .version_id = 1, | |
463 | .minimum_version_id = 1, | |
464 | .fields = (VMStateField[]) { | |
465 | VMSTATE_PTIMER(timer, CMSDKAPBDualTimerModule), | |
466 | VMSTATE_UINT32(load, CMSDKAPBDualTimerModule), | |
467 | VMSTATE_UINT32(value, CMSDKAPBDualTimerModule), | |
468 | VMSTATE_UINT32(control, CMSDKAPBDualTimerModule), | |
469 | VMSTATE_UINT32(intstatus, CMSDKAPBDualTimerModule), | |
470 | VMSTATE_END_OF_LIST() | |
471 | } | |
472 | }; | |
473 | ||
474 | static const VMStateDescription cmsdk_apb_dualtimer_vmstate = { | |
475 | .name = "cmsdk-apb-dualtimer", | |
476 | .version_id = 1, | |
477 | .minimum_version_id = 1, | |
478 | .fields = (VMStateField[]) { | |
479 | VMSTATE_STRUCT_ARRAY(timermod, CMSDKAPBDualTimer, | |
480 | CMSDK_APB_DUALTIMER_NUM_MODULES, | |
481 | 1, cmsdk_dualtimermod_vmstate, | |
482 | CMSDKAPBDualTimerModule), | |
483 | VMSTATE_UINT32(timeritcr, CMSDKAPBDualTimer), | |
484 | VMSTATE_UINT32(timeritop, CMSDKAPBDualTimer), | |
485 | VMSTATE_END_OF_LIST() | |
486 | } | |
487 | }; | |
488 | ||
489 | static Property cmsdk_apb_dualtimer_properties[] = { | |
490 | DEFINE_PROP_UINT32("pclk-frq", CMSDKAPBDualTimer, pclk_frq, 0), | |
491 | DEFINE_PROP_END_OF_LIST(), | |
492 | }; | |
493 | ||
494 | static void cmsdk_apb_dualtimer_class_init(ObjectClass *klass, void *data) | |
495 | { | |
496 | DeviceClass *dc = DEVICE_CLASS(klass); | |
497 | ||
498 | dc->realize = cmsdk_apb_dualtimer_realize; | |
499 | dc->vmsd = &cmsdk_apb_dualtimer_vmstate; | |
500 | dc->reset = cmsdk_apb_dualtimer_reset; | |
501 | dc->props = cmsdk_apb_dualtimer_properties; | |
502 | } | |
503 | ||
504 | static const TypeInfo cmsdk_apb_dualtimer_info = { | |
505 | .name = TYPE_CMSDK_APB_DUALTIMER, | |
506 | .parent = TYPE_SYS_BUS_DEVICE, | |
507 | .instance_size = sizeof(CMSDKAPBDualTimer), | |
508 | .instance_init = cmsdk_apb_dualtimer_init, | |
509 | .class_init = cmsdk_apb_dualtimer_class_init, | |
510 | }; | |
511 | ||
512 | static void cmsdk_apb_dualtimer_register_types(void) | |
513 | { | |
514 | type_register_static(&cmsdk_apb_dualtimer_info); | |
515 | } | |
516 | ||
517 | type_init(cmsdk_apb_dualtimer_register_types); |