hw/timer/grlib_gptimer.c

   1 /*
   2  * QEMU GRLIB GPTimer Emulator
   3  *
   4  * Copyright (c) 2010-2011 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/sysbus.h"
  27 #include "qemu/timer.h"
  28 #include "hw/ptimer.h"
  29 #include "qemu/timer.h"
  30 #include "qemu/main-loop.h"
  31
  32 #include "trace.h"
  33
  34 #define UNIT_REG_SIZE    16     /* Size of memory mapped regs for the unit */
  35 #define GPTIMER_REG_SIZE 16     /* Size of memory mapped regs for a GPTimer */
  36
  37 #define GPTIMER_MAX_TIMERS 8
  38
  39 /* GPTimer Config register fields */
  40 #define GPTIMER_ENABLE      (1 << 0)
  41 #define GPTIMER_RESTART     (1 << 1)
  42 #define GPTIMER_LOAD        (1 << 2)
  43 #define GPTIMER_INT_ENABLE  (1 << 3)
  44 #define GPTIMER_INT_PENDING (1 << 4)
  45 #define GPTIMER_CHAIN       (1 << 5) /* Not supported */
  46 #define GPTIMER_DEBUG_HALT  (1 << 6) /* Not supported */
  47
  48 /* Memory mapped register offsets */
  49 #define SCALER_OFFSET         0x00
  50 #define SCALER_RELOAD_OFFSET  0x04
  51 #define CONFIG_OFFSET         0x08
  52 #define COUNTER_OFFSET        0x00
  53 #define COUNTER_RELOAD_OFFSET 0x04
  54 #define TIMER_BASE            0x10
  55
  56 #define TYPE_GRLIB_GPTIMER "grlib,gptimer"
  57 #define GRLIB_GPTIMER(obj) \
  58     OBJECT_CHECK(GPTimerUnit, (obj), TYPE_GRLIB_GPTIMER)
  59
  60 typedef struct GPTimer     GPTimer;
  61 typedef struct GPTimerUnit GPTimerUnit;
  62
  63 struct GPTimer {
  64     QEMUBH *bh;
  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
  94 static void grlib_gptimer_enable(GPTimer *timer)
  95 {
  96     assert(timer != NULL);
  97
  98
  99     ptimer_stop(timer->ptimer);
 100
 101     if (!(timer->config & GPTIMER_ENABLE)) {
 102         /* Timer disabled */
 103         trace_grlib_gptimer_disabled(timer->id, timer->config);
 104         return;
 105     }
 106
 107     /* ptimer is triggered when the counter reach 0 but GPTimer is triggered at
 108        underflow. Set count + 1 to simulate the GPTimer behavior. */
 109
 110     trace_grlib_gptimer_enable(timer->id, timer->counter);
 111
 112     ptimer_set_count(timer->ptimer, (uint64_t)timer->counter + 1);
 113     ptimer_run(timer->ptimer, 1);
 114 }
 115
 116 static void grlib_gptimer_restart(GPTimer *timer)
 117 {
 118     assert(timer != NULL);
 119
 120     trace_grlib_gptimer_restart(timer->id, timer->reload);
 121
 122     timer->counter = timer->reload;
 123     grlib_gptimer_enable(timer);
 124 }
 125
 126 static void grlib_gptimer_set_scaler(GPTimerUnit *unit, uint32_t scaler)
 127 {
 128     int i = 0;
 129     uint32_t value = 0;
 130
 131     assert(unit != NULL);
 132
 133     if (scaler > 0) {
 134         value = unit->freq_hz / (scaler + 1);
 135     } else {
 136         value = unit->freq_hz;
 137     }
 138
 139     trace_grlib_gptimer_set_scaler(scaler, value);
 140
 141     for (i = 0; i < unit->nr_timers; i++) {
 142         ptimer_set_freq(unit->timers[i].ptimer, value);
 143     }
 144 }
 145
 146 static void grlib_gptimer_hit(void *opaque)
 147 {
 148     GPTimer *timer = opaque;
 149     assert(timer != NULL);
 150
 151     trace_grlib_gptimer_hit(timer->id);
 152
 153     /* Timer expired */
 154
 155     if (timer->config & GPTIMER_INT_ENABLE) {
 156         /* Set the pending bit (only unset by write in the config register) */
 157         timer->config |= GPTIMER_INT_PENDING;
 158         qemu_irq_pulse(timer->irq);
 159     }
 160
 161     if (timer->config & GPTIMER_RESTART) {
 162         grlib_gptimer_restart(timer);
 163     }
 164 }
 165
 166 static uint64_t grlib_gptimer_read(void *opaque, hwaddr addr,
 167                                    unsigned size)
 168 {
 169     GPTimerUnit        *unit  = opaque;
 170     hwaddr  timer_addr;
 171     int                 id;
 172     uint32_t            value = 0;
 173
 174     addr &= 0xff;
 175
 176     /* Unit registers */
 177     switch (addr) {
 178     case SCALER_OFFSET:
 179         trace_grlib_gptimer_readl(-1, addr, unit->scaler);
 180         return unit->scaler;
 181
 182     case SCALER_RELOAD_OFFSET:
 183         trace_grlib_gptimer_readl(-1, addr, unit->reload);
 184         return unit->reload;
 185
 186     case CONFIG_OFFSET:
 187         trace_grlib_gptimer_readl(-1, addr, unit->config);
 188         return unit->config;
 189
 190     default:
 191         break;
 192     }
 193
 194     timer_addr = (addr % TIMER_BASE);
 195     id         = (addr - TIMER_BASE) / TIMER_BASE;
 196
 197     if (id >= 0 && id < unit->nr_timers) {
 198
 199         /* GPTimer registers */
 200         switch (timer_addr) {
 201         case COUNTER_OFFSET:
 202             value = ptimer_get_count(unit->timers[id].ptimer);
 203             trace_grlib_gptimer_readl(id, addr, value);
 204             return value;
 205
 206         case COUNTER_RELOAD_OFFSET:
 207             value = unit->timers[id].reload;
 208             trace_grlib_gptimer_readl(id, addr, value);
 209             return value;
 210
 211         case CONFIG_OFFSET:
 212             trace_grlib_gptimer_readl(id, addr, unit->timers[id].config);
 213             return unit->timers[id].config;
 214
 215         default:
 216             break;
 217         }
 218
 219     }
 220
 221     trace_grlib_gptimer_readl(-1, addr, 0);
 222     return 0;
 223 }
 224
 225 static void grlib_gptimer_write(void *opaque, hwaddr addr,
 226                                 uint64_t value, unsigned size)
 227 {
 228     GPTimerUnit        *unit = opaque;
 229     hwaddr  timer_addr;
 230     int                 id;
 231
 232     addr &= 0xff;
 233
 234     /* Unit registers */
 235     switch (addr) {
 236     case SCALER_OFFSET:
 237         value &= 0xFFFF; /* clean up the value */
 238         unit->scaler = value;
 239         trace_grlib_gptimer_writel(-1, addr, unit->scaler);
 240         return;
 241
 242     case SCALER_RELOAD_OFFSET:
 243         value &= 0xFFFF; /* clean up the value */
 244         unit->reload = value;
 245         trace_grlib_gptimer_writel(-1, addr, unit->reload);
 246         grlib_gptimer_set_scaler(unit, value);
 247         return;
 248
 249     case CONFIG_OFFSET:
 250         /* Read Only (disable timer freeze not supported) */
 251         trace_grlib_gptimer_writel(-1, addr, 0);
 252         return;
 253
 254     default:
 255         break;
 256     }
 257
 258     timer_addr = (addr % TIMER_BASE);
 259     id         = (addr - TIMER_BASE) / TIMER_BASE;
 260
 261     if (id >= 0 && id < unit->nr_timers) {
 262
 263         /* GPTimer registers */
 264         switch (timer_addr) {
 265         case COUNTER_OFFSET:
 266             trace_grlib_gptimer_writel(id, addr, value);
 267             unit->timers[id].counter = value;
 268             grlib_gptimer_enable(&unit->timers[id]);
 269             return;
 270
 271         case COUNTER_RELOAD_OFFSET:
 272             trace_grlib_gptimer_writel(id, addr, value);
 273             unit->timers[id].reload = value;
 274             return;
 275
 276         case CONFIG_OFFSET:
 277             trace_grlib_gptimer_writel(id, addr, value);
 278
 279             if (value & GPTIMER_INT_PENDING) {
 280                 /* clear pending bit */
 281                 value &= ~GPTIMER_INT_PENDING;
 282             } else {
 283                 /* keep pending bit */
 284                 value |= unit->timers[id].config & GPTIMER_INT_PENDING;
 285             }
 286
 287             unit->timers[id].config = value;
 288
 289             /* gptimer_restart calls gptimer_enable, so if "enable" and "load"
 290                bits are present, we just have to call restart. */
 291
 292             if (value & GPTIMER_LOAD) {
 293                 grlib_gptimer_restart(&unit->timers[id]);
 294             } else if (value & GPTIMER_ENABLE) {
 295                 grlib_gptimer_enable(&unit->timers[id]);
 296             }
 297
 298             /* These fields must always be read as 0 */
 299             value &= ~(GPTIMER_LOAD & GPTIMER_DEBUG_HALT);
 300
 301             unit->timers[id].config = value;
 302             return;
 303
 304         default:
 305             break;
 306         }
 307
 308     }
 309
 310     trace_grlib_gptimer_writel(-1, addr, value);
 311 }
 312
 313 static const MemoryRegionOps grlib_gptimer_ops = {
 314     .read = grlib_gptimer_read,
 315     .write = grlib_gptimer_write,
 316     .endianness = DEVICE_NATIVE_ENDIAN,
 317     .valid = {
 318         .min_access_size = 4,
 319         .max_access_size = 4,
 320     },
 321 };
 322
 323 static void grlib_gptimer_reset(DeviceState *d)
 324 {
 325     GPTimerUnit *unit = GRLIB_GPTIMER(d);
 326     int          i    = 0;
 327
 328     assert(unit != NULL);
 329
 330     unit->scaler = 0;
 331     unit->reload = 0;
 332
 333     unit->config  = unit->nr_timers;
 334     unit->config |= unit->irq_line << 3;
 335     unit->config |= 1 << 8;     /* separate interrupt */
 336     unit->config |= 1 << 9;     /* Disable timer freeze */
 337
 338
 339     for (i = 0; i < unit->nr_timers; i++) {
 340         GPTimer *timer = &unit->timers[i];
 341
 342         timer->counter = 0;
 343         timer->reload = 0;
 344         timer->config = 0;
 345         ptimer_stop(timer->ptimer);
 346         ptimer_set_count(timer->ptimer, 0);
 347         ptimer_set_freq(timer->ptimer, unit->freq_hz);
 348     }
 349 }
 350
 351 static int grlib_gptimer_init(SysBusDevice *dev)
 352 {
 353     GPTimerUnit  *unit = GRLIB_GPTIMER(dev);
 354     unsigned int  i;
 355
 356     assert(unit->nr_timers > 0);
 357     assert(unit->nr_timers <= GPTIMER_MAX_TIMERS);
 358
 359     unit->timers = g_malloc0(sizeof unit->timers[0] * unit->nr_timers);
 360
 361     for (i = 0; i < unit->nr_timers; i++) {
 362         GPTimer *timer = &unit->timers[i];
 363
 364         timer->unit   = unit;
 365         timer->bh     = qemu_bh_new(grlib_gptimer_hit, timer);
 366         timer->ptimer = ptimer_init(timer->bh);
 367         timer->id     = i;
 368
 369         /* One IRQ line for each timer */
 370         sysbus_init_irq(dev, &timer->irq);
 371
 372         ptimer_set_freq(timer->ptimer, unit->freq_hz);
 373     }
 374
 375     memory_region_init_io(&unit->iomem, OBJECT(unit), &grlib_gptimer_ops,
 376                           unit, "gptimer",
 377                           UNIT_REG_SIZE + GPTIMER_REG_SIZE * unit->nr_timers);
 378
 379     sysbus_init_mmio(dev, &unit->iomem);
 380     return 0;
 381 }
 382
 383 static Property grlib_gptimer_properties[] = {
 384     DEFINE_PROP_UINT32("frequency", GPTimerUnit, freq_hz,   40000000),
 385     DEFINE_PROP_UINT32("irq-line",  GPTimerUnit, irq_line,  8),
 386     DEFINE_PROP_UINT32("nr-timers", GPTimerUnit, nr_timers, 2),
 387     DEFINE_PROP_END_OF_LIST(),
 388 };
 389
 390 static void grlib_gptimer_class_init(ObjectClass *klass, void *data)
 391 {
 392     DeviceClass *dc = DEVICE_CLASS(klass);
 393     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 394
 395     k->init = grlib_gptimer_init;
 396     dc->reset = grlib_gptimer_reset;
 397     dc->props = grlib_gptimer_properties;
 398 }
 399
 400 static const TypeInfo grlib_gptimer_info = {
 401     .name          = TYPE_GRLIB_GPTIMER,
 402     .parent        = TYPE_SYS_BUS_DEVICE,
 403     .instance_size = sizeof(GPTimerUnit),
 404     .class_init    = grlib_gptimer_class_init,
 405 };
 406
 407 static void grlib_gptimer_register_types(void)
 408 {
 409     type_register_static(&grlib_gptimer_info);
 410 }
 411
 412 type_init(grlib_gptimer_register_types)