hw/timer/arm_timer.c

   1 /*
   2  * ARM PrimeCell Timer modules.
   3  *
   4  * Copyright (c) 2005-2006 CodeSourcery.
   5  * Written by Paul Brook
   6  *
   7  * This code is licensed under the GPL.
   8  */
   9
  10 #include "qemu/osdep.h"
  11 #include "hw/sysbus.h"
  12 #include "migration/vmstate.h"
  13 #include "qemu/timer.h"
  14 #include "hw/irq.h"
  15 #include "hw/ptimer.h"
  16 #include "hw/qdev-properties.h"
  17 #include "qemu/module.h"
  18 #include "qemu/log.h"
  19
  20 /* Common timer implementation.  */
  21
  22 #define TIMER_CTRL_ONESHOT      (1 << 0)
  23 #define TIMER_CTRL_32BIT        (1 << 1)
  24 #define TIMER_CTRL_DIV1         (0 << 2)
  25 #define TIMER_CTRL_DIV16        (1 << 2)
  26 #define TIMER_CTRL_DIV256       (2 << 2)
  27 #define TIMER_CTRL_IE           (1 << 5)
  28 #define TIMER_CTRL_PERIODIC     (1 << 6)
  29 #define TIMER_CTRL_ENABLE       (1 << 7)
  30
  31 typedef struct {
  32     ptimer_state *timer;
  33     uint32_t control;
  34     uint32_t limit;
  35     int freq;
  36     int int_level;
  37     qemu_irq irq;
  38 } arm_timer_state;
  39
  40 /* Check all active timers, and schedule the next timer interrupt.  */
  41
  42 static void arm_timer_update(arm_timer_state *s)
  43 {
  44     /* Update interrupts.  */
  45     if (s->int_level && (s->control & TIMER_CTRL_IE)) {
  46         qemu_irq_raise(s->irq);
  47     } else {
  48         qemu_irq_lower(s->irq);
  49     }
  50 }
  51
  52 static uint32_t arm_timer_read(void *opaque, hwaddr offset)
  53 {
  54     arm_timer_state *s = (arm_timer_state *)opaque;
  55
  56     switch (offset >> 2) {
  57     case 0: /* TimerLoad */
  58     case 6: /* TimerBGLoad */
  59         return s->limit;
  60     case 1: /* TimerValue */
  61         return ptimer_get_count(s->timer);
  62     case 2: /* TimerControl */
  63         return s->control;
  64     case 4: /* TimerRIS */
  65         return s->int_level;
  66     case 5: /* TimerMIS */
  67         if ((s->control & TIMER_CTRL_IE) == 0)
  68             return 0;
  69         return s->int_level;
  70     default:
  71         qemu_log_mask(LOG_GUEST_ERROR,
  72                       "%s: Bad offset %x\n", __func__, (int)offset);
  73         return 0;
  74     }
  75 }
  76
  77 /*
  78  * Reset the timer limit after settings have changed.
  79  * May only be called from inside a ptimer transaction block.
  80  */
  81 static void arm_timer_recalibrate(arm_timer_state *s, int reload)
  82 {
  83     uint32_t limit;
  84
  85     if ((s->control & (TIMER_CTRL_PERIODIC | TIMER_CTRL_ONESHOT)) == 0) {
  86         /* Free running.  */
  87         if (s->control & TIMER_CTRL_32BIT)
  88             limit = 0xffffffff;
  89         else
  90             limit = 0xffff;
  91     } else {
  92           /* Periodic.  */
  93           limit = s->limit;
  94     }
  95     ptimer_set_limit(s->timer, limit, reload);
  96 }
  97
  98 static void arm_timer_write(void *opaque, hwaddr offset,
  99                             uint32_t value)
 100 {
 101     arm_timer_state *s = (arm_timer_state *)opaque;
 102     int freq;
 103
 104     switch (offset >> 2) {
 105     case 0: /* TimerLoad */
 106         s->limit = value;
 107         ptimer_transaction_begin(s->timer);
 108         arm_timer_recalibrate(s, 1);
 109         ptimer_transaction_commit(s->timer);
 110         break;
 111     case 1: /* TimerValue */
 112         /* ??? Linux seems to want to write to this readonly register.
 113            Ignore it.  */
 114         break;
 115     case 2: /* TimerControl */
 116         ptimer_transaction_begin(s->timer);
 117         if (s->control & TIMER_CTRL_ENABLE) {
 118             /* Pause the timer if it is running.  This may cause some
 119                inaccuracy dure to rounding, but avoids a whole lot of other
 120                messyness.  */
 121             ptimer_stop(s->timer);
 122         }
 123         s->control = value;
 124         freq = s->freq;
 125         /* ??? Need to recalculate expiry time after changing divisor.  */
 126         switch ((value >> 2) & 3) {
 127         case 1: freq >>= 4; break;
 128         case 2: freq >>= 8; break;
 129         }
 130         arm_timer_recalibrate(s, s->control & TIMER_CTRL_ENABLE);
 131         ptimer_set_freq(s->timer, freq);
 132         if (s->control & TIMER_CTRL_ENABLE) {
 133             /* Restart the timer if still enabled.  */
 134             ptimer_run(s->timer, (s->control & TIMER_CTRL_ONESHOT) != 0);
 135         }
 136         ptimer_transaction_commit(s->timer);
 137         break;
 138     case 3: /* TimerIntClr */
 139         s->int_level = 0;
 140         break;
 141     case 6: /* TimerBGLoad */
 142         s->limit = value;
 143         ptimer_transaction_begin(s->timer);
 144         arm_timer_recalibrate(s, 0);
 145         ptimer_transaction_commit(s->timer);
 146         break;
 147     default:
 148         qemu_log_mask(LOG_GUEST_ERROR,
 149                       "%s: Bad offset %x\n", __func__, (int)offset);
 150     }
 151     arm_timer_update(s);
 152 }
 153
 154 static void arm_timer_tick(void *opaque)
 155 {
 156     arm_timer_state *s = (arm_timer_state *)opaque;
 157     s->int_level = 1;
 158     arm_timer_update(s);
 159 }
 160
 161 static const VMStateDescription vmstate_arm_timer = {
 162     .name = "arm_timer",
 163     .version_id = 1,
 164     .minimum_version_id = 1,
 165     .fields = (VMStateField[]) {
 166         VMSTATE_UINT32(control, arm_timer_state),
 167         VMSTATE_UINT32(limit, arm_timer_state),
 168         VMSTATE_INT32(int_level, arm_timer_state),
 169         VMSTATE_PTIMER(timer, arm_timer_state),
 170         VMSTATE_END_OF_LIST()
 171     }
 172 };
 173
 174 static arm_timer_state *arm_timer_init(uint32_t freq)
 175 {
 176     arm_timer_state *s;
 177
 178     s = (arm_timer_state *)g_malloc0(sizeof(arm_timer_state));
 179     s->freq = freq;
 180     s->control = TIMER_CTRL_IE;
 181
 182     s->timer = ptimer_init(arm_timer_tick, s, PTIMER_POLICY_DEFAULT);
 183     vmstate_register(NULL, VMSTATE_INSTANCE_ID_ANY, &vmstate_arm_timer, s);
 184     return s;
 185 }
 186
 187 /* ARM PrimeCell SP804 dual timer module.
 188  * Docs at
 189  * http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0271d/index.html
 190 */
 191
 192 #define TYPE_SP804 "sp804"
 193 #define SP804(obj) OBJECT_CHECK(SP804State, (obj), TYPE_SP804)
 194
 195 typedef struct SP804State {
 196     SysBusDevice parent_obj;
 197
 198     MemoryRegion iomem;
 199     arm_timer_state *timer[2];
 200     uint32_t freq0, freq1;
 201     int level[2];
 202     qemu_irq irq;
 203 } SP804State;
 204
 205 static const uint8_t sp804_ids[] = {
 206     /* Timer ID */
 207     0x04, 0x18, 0x14, 0,
 208     /* PrimeCell ID */
 209     0xd, 0xf0, 0x05, 0xb1
 210 };
 211
 212 /* Merge the IRQs from the two component devices.  */
 213 static void sp804_set_irq(void *opaque, int irq, int level)
 214 {
 215     SP804State *s = (SP804State *)opaque;
 216
 217     s->level[irq] = level;
 218     qemu_set_irq(s->irq, s->level[0] || s->level[1]);
 219 }
 220
 221 static uint64_t sp804_read(void *opaque, hwaddr offset,
 222                            unsigned size)
 223 {
 224     SP804State *s = (SP804State *)opaque;
 225
 226     if (offset < 0x20) {
 227         return arm_timer_read(s->timer[0], offset);
 228     }
 229     if (offset < 0x40) {
 230         return arm_timer_read(s->timer[1], offset - 0x20);
 231     }
 232
 233     /* TimerPeriphID */
 234     if (offset >= 0xfe0 && offset <= 0xffc) {
 235         return sp804_ids[(offset - 0xfe0) >> 2];
 236     }
 237
 238     switch (offset) {
 239     /* Integration Test control registers, which we won't support */
 240     case 0xf00: /* TimerITCR */
 241     case 0xf04: /* TimerITOP (strictly write only but..) */
 242         qemu_log_mask(LOG_UNIMP,
 243                       "%s: integration test registers unimplemented\n",
 244                       __func__);
 245         return 0;
 246     }
 247
 248     qemu_log_mask(LOG_GUEST_ERROR,
 249                   "%s: Bad offset %x\n", __func__, (int)offset);
 250     return 0;
 251 }
 252
 253 static void sp804_write(void *opaque, hwaddr offset,
 254                         uint64_t value, unsigned size)
 255 {
 256     SP804State *s = (SP804State *)opaque;
 257
 258     if (offset < 0x20) {
 259         arm_timer_write(s->timer[0], offset, value);
 260         return;
 261     }
 262
 263     if (offset < 0x40) {
 264         arm_timer_write(s->timer[1], offset - 0x20, value);
 265         return;
 266     }
 267
 268     /* Technically we could be writing to the Test Registers, but not likely */
 269     qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %x\n",
 270                   __func__, (int)offset);
 271 }
 272
 273 static const MemoryRegionOps sp804_ops = {
 274     .read = sp804_read,
 275     .write = sp804_write,
 276     .endianness = DEVICE_NATIVE_ENDIAN,
 277 };
 278
 279 static const VMStateDescription vmstate_sp804 = {
 280     .name = "sp804",
 281     .version_id = 1,
 282     .minimum_version_id = 1,
 283     .fields = (VMStateField[]) {
 284         VMSTATE_INT32_ARRAY(level, SP804State, 2),
 285         VMSTATE_END_OF_LIST()
 286     }
 287 };
 288
 289 static void sp804_init(Object *obj)
 290 {
 291     SP804State *s = SP804(obj);
 292     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
 293
 294     sysbus_init_irq(sbd, &s->irq);
 295     memory_region_init_io(&s->iomem, obj, &sp804_ops, s,
 296                           "sp804", 0x1000);
 297     sysbus_init_mmio(sbd, &s->iomem);
 298 }
 299
 300 static void sp804_realize(DeviceState *dev, Error **errp)
 301 {
 302     SP804State *s = SP804(dev);
 303
 304     s->timer[0] = arm_timer_init(s->freq0);
 305     s->timer[1] = arm_timer_init(s->freq1);
 306     s->timer[0]->irq = qemu_allocate_irq(sp804_set_irq, s, 0);
 307     s->timer[1]->irq = qemu_allocate_irq(sp804_set_irq, s, 1);
 308 }
 309
 310 /* Integrator/CP timer module.  */
 311
 312 #define TYPE_INTEGRATOR_PIT "integrator_pit"
 313 #define INTEGRATOR_PIT(obj) \
 314     OBJECT_CHECK(icp_pit_state, (obj), TYPE_INTEGRATOR_PIT)
 315
 316 typedef struct {
 317     SysBusDevice parent_obj;
 318
 319     MemoryRegion iomem;
 320     arm_timer_state *timer[3];
 321 } icp_pit_state;
 322
 323 static uint64_t icp_pit_read(void *opaque, hwaddr offset,
 324                              unsigned size)
 325 {
 326     icp_pit_state *s = (icp_pit_state *)opaque;
 327     int n;
 328
 329     /* ??? Don't know the PrimeCell ID for this device.  */
 330     n = offset >> 8;
 331     if (n > 2) {
 332         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad timer %d\n", __func__, n);
 333         return 0;
 334     }
 335
 336     return arm_timer_read(s->timer[n], offset & 0xff);
 337 }
 338
 339 static void icp_pit_write(void *opaque, hwaddr offset,
 340                           uint64_t value, unsigned size)
 341 {
 342     icp_pit_state *s = (icp_pit_state *)opaque;
 343     int n;
 344
 345     n = offset >> 8;
 346     if (n > 2) {
 347         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad timer %d\n", __func__, n);
 348         return;
 349     }
 350
 351     arm_timer_write(s->timer[n], offset & 0xff, value);
 352 }
 353
 354 static const MemoryRegionOps icp_pit_ops = {
 355     .read = icp_pit_read,
 356     .write = icp_pit_write,
 357     .endianness = DEVICE_NATIVE_ENDIAN,
 358 };
 359
 360 static void icp_pit_init(Object *obj)
 361 {
 362     icp_pit_state *s = INTEGRATOR_PIT(obj);
 363     SysBusDevice *dev = SYS_BUS_DEVICE(obj);
 364
 365     /* Timer 0 runs at the system clock speed (40MHz).  */
 366     s->timer[0] = arm_timer_init(40000000);
 367     /* The other two timers run at 1MHz.  */
 368     s->timer[1] = arm_timer_init(1000000);
 369     s->timer[2] = arm_timer_init(1000000);
 370
 371     sysbus_init_irq(dev, &s->timer[0]->irq);
 372     sysbus_init_irq(dev, &s->timer[1]->irq);
 373     sysbus_init_irq(dev, &s->timer[2]->irq);
 374
 375     memory_region_init_io(&s->iomem, obj, &icp_pit_ops, s,
 376                           "icp_pit", 0x1000);
 377     sysbus_init_mmio(dev, &s->iomem);
 378     /* This device has no state to save/restore.  The component timers will
 379        save themselves.  */
 380 }
 381
 382 static const TypeInfo icp_pit_info = {
 383     .name          = TYPE_INTEGRATOR_PIT,
 384     .parent        = TYPE_SYS_BUS_DEVICE,
 385     .instance_size = sizeof(icp_pit_state),
 386     .instance_init = icp_pit_init,
 387 };
 388
 389 static Property sp804_properties[] = {
 390     DEFINE_PROP_UINT32("freq0", SP804State, freq0, 1000000),
 391     DEFINE_PROP_UINT32("freq1", SP804State, freq1, 1000000),
 392     DEFINE_PROP_END_OF_LIST(),
 393 };
 394
 395 static void sp804_class_init(ObjectClass *klass, void *data)
 396 {
 397     DeviceClass *k = DEVICE_CLASS(klass);
 398
 399     k->realize = sp804_realize;
 400     k->props = sp804_properties;
 401     k->vmsd = &vmstate_sp804;
 402 }
 403
 404 static const TypeInfo sp804_info = {
 405     .name          = TYPE_SP804,
 406     .parent        = TYPE_SYS_BUS_DEVICE,
 407     .instance_size = sizeof(SP804State),
 408     .instance_init = sp804_init,
 409     .class_init    = sp804_class_init,
 410 };
 411
 412 static void arm_timer_register_types(void)
 413 {
 414     type_register_static(&icp_pit_info);
 415     type_register_static(&sp804_info);
 416 }
 417
 418 type_init(arm_timer_register_types)