1 /*
2 * QEMU GRLIB GPTimer Emulator
3 *
4 * Copyright (c) 2010-2019 AdaCore
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24
25 #include "qemu/osdep.h"
26 #include "hw/sparc/grlib.h"
27 #include "hw/sysbus.h"
28 #include "qemu/timer.h"
29 #include "hw/irq.h"
30 #include "hw/ptimer.h"
31 #include "hw/qdev-properties.h"
32 #include "qemu/module.h"
33
34 #include "trace.h"
35
36 #define UNIT_REG_SIZE 16 /* Size of memory mapped regs for the unit */
37 #define GPTIMER_REG_SIZE 16 /* Size of memory mapped regs for a GPTimer */
38
39 #define GPTIMER_MAX_TIMERS 8
40
41 /* GPTimer Config register fields */
42 #define GPTIMER_ENABLE (1 << 0)
43 #define GPTIMER_RESTART (1 << 1)
44 #define GPTIMER_LOAD (1 << 2)
45 #define GPTIMER_INT_ENABLE (1 << 3)
46 #define GPTIMER_INT_PENDING (1 << 4)
47 #define GPTIMER_CHAIN (1 << 5) /* Not supported */
48 #define GPTIMER_DEBUG_HALT (1 << 6) /* Not supported */
49
50 /* Memory mapped register offsets */
51 #define SCALER_OFFSET 0x00
52 #define SCALER_RELOAD_OFFSET 0x04
53 #define CONFIG_OFFSET 0x08
54 #define COUNTER_OFFSET 0x00
55 #define COUNTER_RELOAD_OFFSET 0x04
56 #define TIMER_BASE 0x10
57
58 #define GRLIB_GPTIMER(obj) \
59 OBJECT_CHECK(GPTimerUnit, (obj), TYPE_GRLIB_GPTIMER)
60
61 typedef struct GPTimer GPTimer;
62 typedef struct GPTimerUnit GPTimerUnit;
63
64 struct GPTimer {
65 struct ptimer_state *ptimer;
66
67 qemu_irq irq;
68 int id;
69 GPTimerUnit *unit;
70
71 /* registers */
72 uint32_t counter;
73 uint32_t reload;
74 uint32_t config;
75 };
76
77 struct GPTimerUnit {
78 SysBusDevice parent_obj;
79
80 MemoryRegion iomem;
81
82 uint32_t nr_timers; /* Number of timers available */
83 uint32_t freq_hz; /* System frequency */
84 uint32_t irq_line; /* Base irq line */
85
86 GPTimer *timers;
87
88 /* registers */
89 uint32_t scaler;
90 uint32_t reload;
91 uint32_t config;
92 };
93
grlib_gptimer_tx_begin(GPTimer * timer)94 static void grlib_gptimer_tx_begin(GPTimer *timer)
95 {
96 ptimer_transaction_begin(timer->ptimer);
97 }
98
grlib_gptimer_tx_commit(GPTimer * timer)99 static void grlib_gptimer_tx_commit(GPTimer *timer)
100 {
101 ptimer_transaction_commit(timer->ptimer);
102 }
103
104 /* Must be called within grlib_gptimer_tx_begin/commit block */
grlib_gptimer_enable(GPTimer * timer)105 static void grlib_gptimer_enable(GPTimer *timer)
106 {
107 assert(timer != NULL);
108
109
110 ptimer_stop(timer->ptimer);
111
112 if (!(timer->config & GPTIMER_ENABLE)) {
113 /* Timer disabled */
114 trace_grlib_gptimer_disabled(timer->id, timer->config);
115 return;
116 }
117
118 /* ptimer is triggered when the counter reach 0 but GPTimer is triggered at
119 underflow. Set count + 1 to simulate the GPTimer behavior. */
120
121 trace_grlib_gptimer_enable(timer->id, timer->counter);
122
123 ptimer_set_count(timer->ptimer, (uint64_t)timer->counter + 1);
124 ptimer_run(timer->ptimer, 1);
125 }
126
127 /* Must be called within grlib_gptimer_tx_begin/commit block */
grlib_gptimer_restart(GPTimer * timer)128 static void grlib_gptimer_restart(GPTimer *timer)
129 {
130 assert(timer != NULL);
131
132 trace_grlib_gptimer_restart(timer->id, timer->reload);
133
134 timer->counter = timer->reload;
135 grlib_gptimer_enable(timer);
136 }
137
grlib_gptimer_set_scaler(GPTimerUnit * unit,uint32_t scaler)138 static void grlib_gptimer_set_scaler(GPTimerUnit *unit, uint32_t scaler)
139 {
140 int i = 0;
141 uint32_t value = 0;
142
143 assert(unit != NULL);
144
145 if (scaler > 0) {
146 value = unit->freq_hz / (scaler + 1);
147 } else {
148 value = unit->freq_hz;
149 }
150
151 trace_grlib_gptimer_set_scaler(scaler, value);
152
153 for (i = 0; i < unit->nr_timers; i++) {
154 ptimer_transaction_begin(unit->timers[i].ptimer);
155 ptimer_set_freq(unit->timers[i].ptimer, value);
156 ptimer_transaction_commit(unit->timers[i].ptimer);
157 }
158 }
159
grlib_gptimer_hit(void * opaque)160 static void grlib_gptimer_hit(void *opaque)
161 {
162 GPTimer *timer = opaque;
163 assert(timer != NULL);
164
165 trace_grlib_gptimer_hit(timer->id);
166
167 /* Timer expired */
168
169 if (timer->config & GPTIMER_INT_ENABLE) {
170 /* Set the pending bit (only unset by write in the config register) */
171 timer->config |= GPTIMER_INT_PENDING;
172 qemu_irq_pulse(timer->irq);
173 }
174
175 if (timer->config & GPTIMER_RESTART) {
176 grlib_gptimer_restart(timer);
177 }
178 }
179
grlib_gptimer_read(void * opaque,hwaddr addr,unsigned size)180 static uint64_t grlib_gptimer_read(void *opaque, hwaddr addr,
181 unsigned size)
182 {
183 GPTimerUnit *unit = opaque;
184 hwaddr timer_addr;
185 int id;
186 uint32_t value = 0;
187
188 addr &= 0xff;
189
190 /* Unit registers */
191 switch (addr) {
192 case SCALER_OFFSET:
193 trace_grlib_gptimer_readl(-1, addr, unit->scaler);
194 return unit->scaler;
195
196 case SCALER_RELOAD_OFFSET:
197 trace_grlib_gptimer_readl(-1, addr, unit->reload);
198 return unit->reload;
199
200 case CONFIG_OFFSET:
201 trace_grlib_gptimer_readl(-1, addr, unit->config);
202 return unit->config;
203
204 default:
205 break;
206 }
207
208 timer_addr = (addr % TIMER_BASE);
209 id = (addr - TIMER_BASE) / TIMER_BASE;
210
211 if (id >= 0 && id < unit->nr_timers) {
212
213 /* GPTimer registers */
214 switch (timer_addr) {
215 case COUNTER_OFFSET:
216 value = ptimer_get_count(unit->timers[id].ptimer);
217 trace_grlib_gptimer_readl(id, addr, value);
218 return value;
219
220 case COUNTER_RELOAD_OFFSET:
221 value = unit->timers[id].reload;
222 trace_grlib_gptimer_readl(id, addr, value);
223 return value;
224
225 case CONFIG_OFFSET:
226 trace_grlib_gptimer_readl(id, addr, unit->timers[id].config);
227 return unit->timers[id].config;
228
229 default:
230 break;
231 }
232
233 }
234
235 trace_grlib_gptimer_readl(-1, addr, 0);
236 return 0;
237 }
238
grlib_gptimer_write(void * opaque,hwaddr addr,uint64_t value,unsigned size)239 static void grlib_gptimer_write(void *opaque, hwaddr addr,
240 uint64_t value, unsigned size)
241 {
242 GPTimerUnit *unit = opaque;
243 hwaddr timer_addr;
244 int id;
245
246 addr &= 0xff;
247
248 /* Unit registers */
249 switch (addr) {
250 case SCALER_OFFSET:
251 value &= 0xFFFF; /* clean up the value */
252 unit->scaler = value;
253 trace_grlib_gptimer_writel(-1, addr, unit->scaler);
254 return;
255
256 case SCALER_RELOAD_OFFSET:
257 value &= 0xFFFF; /* clean up the value */
258 unit->reload = value;
259 trace_grlib_gptimer_writel(-1, addr, unit->reload);
260 grlib_gptimer_set_scaler(unit, value);
261 return;
262
263 case CONFIG_OFFSET:
264 /* Read Only (disable timer freeze not supported) */
265 trace_grlib_gptimer_writel(-1, addr, 0);
266 return;
267
268 default:
269 break;
270 }
271
272 timer_addr = (addr % TIMER_BASE);
273 id = (addr - TIMER_BASE) / TIMER_BASE;
274
275 if (id >= 0 && id < unit->nr_timers) {
276
277 /* GPTimer registers */
278 switch (timer_addr) {
279 case COUNTER_OFFSET:
280 trace_grlib_gptimer_writel(id, addr, value);
281 grlib_gptimer_tx_begin(&unit->timers[id]);
282 unit->timers[id].counter = value;
283 grlib_gptimer_enable(&unit->timers[id]);
284 grlib_gptimer_tx_commit(&unit->timers[id]);
285 return;
286
287 case COUNTER_RELOAD_OFFSET:
288 trace_grlib_gptimer_writel(id, addr, value);
289 unit->timers[id].reload = value;
290 return;
291
292 case CONFIG_OFFSET:
293 trace_grlib_gptimer_writel(id, addr, value);
294
295 if (value & GPTIMER_INT_PENDING) {
296 /* clear pending bit */
297 value &= ~GPTIMER_INT_PENDING;
298 } else {
299 /* keep pending bit */
300 value |= unit->timers[id].config & GPTIMER_INT_PENDING;
301 }
302
303 unit->timers[id].config = value;
304
305 /* gptimer_restart calls gptimer_enable, so if "enable" and "load"
306 bits are present, we just have to call restart. */
307
308 grlib_gptimer_tx_begin(&unit->timers[id]);
309 if (value & GPTIMER_LOAD) {
310 grlib_gptimer_restart(&unit->timers[id]);
311 } else if (value & GPTIMER_ENABLE) {
312 grlib_gptimer_enable(&unit->timers[id]);
313 }
314
315 /* These fields must always be read as 0 */
316 value &= ~(GPTIMER_LOAD & GPTIMER_DEBUG_HALT);
317
318 unit->timers[id].config = value;
319 grlib_gptimer_tx_commit(&unit->timers[id]);
320 return;
321
322 default:
323 break;
324 }
325
326 }
327
328 trace_grlib_gptimer_writel(-1, addr, value);
329 }
330
331 static const MemoryRegionOps grlib_gptimer_ops = {
332 .read = grlib_gptimer_read,
333 .write = grlib_gptimer_write,
334 .endianness = DEVICE_NATIVE_ENDIAN,
335 .valid = {
336 .min_access_size = 4,
337 .max_access_size = 4,
338 },
339 };
340
grlib_gptimer_reset(DeviceState * d)341 static void grlib_gptimer_reset(DeviceState *d)
342 {
343 GPTimerUnit *unit = GRLIB_GPTIMER(d);
344 int i = 0;
345
346 assert(unit != NULL);
347
348 unit->scaler = 0;
349 unit->reload = 0;
350
351 unit->config = unit->nr_timers;
352 unit->config |= unit->irq_line << 3;
353 unit->config |= 1 << 8; /* separate interrupt */
354 unit->config |= 1 << 9; /* Disable timer freeze */
355
356
357 for (i = 0; i < unit->nr_timers; i++) {
358 GPTimer *timer = &unit->timers[i];
359
360 timer->counter = 0;
361 timer->reload = 0;
362 timer->config = 0;
363 ptimer_transaction_begin(timer->ptimer);
364 ptimer_stop(timer->ptimer);
365 ptimer_set_count(timer->ptimer, 0);
366 ptimer_set_freq(timer->ptimer, unit->freq_hz);
367 ptimer_transaction_commit(timer->ptimer);
368 }
369 }
370
grlib_gptimer_realize(DeviceState * dev,Error ** errp)371 static void grlib_gptimer_realize(DeviceState *dev, Error **errp)
372 {
373 GPTimerUnit *unit = GRLIB_GPTIMER(dev);
374 unsigned int i;
375 SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
376
377 assert(unit->nr_timers > 0);
378 assert(unit->nr_timers <= GPTIMER_MAX_TIMERS);
379
380 unit->timers = g_malloc0(sizeof unit->timers[0] * unit->nr_timers);
381
382 for (i = 0; i < unit->nr_timers; i++) {
383 GPTimer *timer = &unit->timers[i];
384
385 timer->unit = unit;
386 timer->ptimer = ptimer_init(grlib_gptimer_hit, timer,
387 PTIMER_POLICY_DEFAULT);
388 timer->id = i;
389
390 /* One IRQ line for each timer */
391 sysbus_init_irq(sbd, &timer->irq);
392
393 ptimer_transaction_begin(timer->ptimer);
394 ptimer_set_freq(timer->ptimer, unit->freq_hz);
395 ptimer_transaction_commit(timer->ptimer);
396 }
397
398 memory_region_init_io(&unit->iomem, OBJECT(unit), &grlib_gptimer_ops,
399 unit, "gptimer",
400 UNIT_REG_SIZE + GPTIMER_REG_SIZE * unit->nr_timers);
401
402 sysbus_init_mmio(sbd, &unit->iomem);
403 }
404
405 static Property grlib_gptimer_properties[] = {
406 DEFINE_PROP_UINT32("frequency", GPTimerUnit, freq_hz, 40000000),
407 DEFINE_PROP_UINT32("irq-line", GPTimerUnit, irq_line, 8),
408 DEFINE_PROP_UINT32("nr-timers", GPTimerUnit, nr_timers, 2),
409 DEFINE_PROP_END_OF_LIST(),
410 };
411
grlib_gptimer_class_init(ObjectClass * klass,void * data)412 static void grlib_gptimer_class_init(ObjectClass *klass, void *data)
413 {
414 DeviceClass *dc = DEVICE_CLASS(klass);
415
416 dc->realize = grlib_gptimer_realize;
417 dc->reset = grlib_gptimer_reset;
418 device_class_set_props(dc, grlib_gptimer_properties);
419 }
420
421 static const TypeInfo grlib_gptimer_info = {
422 .name = TYPE_GRLIB_GPTIMER,
423 .parent = TYPE_SYS_BUS_DEVICE,
424 .instance_size = sizeof(GPTimerUnit),
425 .class_init = grlib_gptimer_class_init,
426 };
427
grlib_gptimer_register_types(void)428 static void grlib_gptimer_register_types(void)
429 {
430 type_register_static(&grlib_gptimer_info);
431 }
432
433 type_init(grlib_gptimer_register_types)
434