hw/timer/grlib_gptimer.c

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