hw/arm_mptimer.c

   1 /*
   2  * Private peripheral timer/watchdog blocks for ARM 11MPCore and A9MP
   3  *
   4  * Copyright (c) 2006-2007 CodeSourcery.
   5  * Copyright (c) 2011 Linaro Limited
   6  * Written by Paul Brook, Peter Maydell
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * as published by the Free Software Foundation; either version
  11  * 2 of the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with this program; if not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include "sysbus.h"
  23 #include "qemu-timer.h"
  24
  25 /* This device implements the per-cpu private timer and watchdog block
  26  * which is used in both the ARM11MPCore and Cortex-A9MP.
  27  */
  28
  29 #define MAX_CPUS 4
  30
  31 /* State of a single timer or watchdog block */
  32 typedef struct {
  33     uint32_t count;
  34     uint32_t load;
  35     uint32_t control;
  36     uint32_t status;
  37     int64_t tick;
  38     QEMUTimer *timer;
  39     qemu_irq irq;
  40     MemoryRegion iomem;
  41 } timerblock;
  42
  43 typedef struct {
  44     SysBusDevice busdev;
  45     uint32_t num_cpu;
  46     timerblock timerblock[MAX_CPUS * 2];
  47     MemoryRegion iomem[2];
  48 } arm_mptimer_state;
  49
  50 static inline int get_current_cpu(arm_mptimer_state *s)
  51 {
  52     if (cpu_single_env->cpu_index >= s->num_cpu) {
  53         hw_error("arm_mptimer: num-cpu %d but this cpu is %d!\n",
  54                  s->num_cpu, cpu_single_env->cpu_index);
  55     }
  56     return cpu_single_env->cpu_index;
  57 }
  58
  59 static inline void timerblock_update_irq(timerblock *tb)
  60 {
  61     qemu_set_irq(tb->irq, tb->status);
  62 }
  63
  64 /* Return conversion factor from mpcore timer ticks to qemu timer ticks.  */
  65 static inline uint32_t timerblock_scale(timerblock *tb)
  66 {
  67     return (((tb->control >> 8) & 0xff) + 1) * 10;
  68 }
  69
  70 static void timerblock_reload(timerblock *tb, int restart)
  71 {
  72     if (tb->count == 0) {
  73         return;
  74     }
  75     if (restart) {
  76         tb->tick = qemu_get_clock_ns(vm_clock);
  77     }
  78     tb->tick += (int64_t)tb->count * timerblock_scale(tb);
  79     qemu_mod_timer(tb->timer, tb->tick);
  80 }
  81
  82 static void timerblock_tick(void *opaque)
  83 {
  84     timerblock *tb = (timerblock *)opaque;
  85     tb->status = 1;
  86     if (tb->control & 2) {
  87         tb->count = tb->load;
  88         timerblock_reload(tb, 0);
  89     } else {
  90         tb->count = 0;
  91     }
  92     timerblock_update_irq(tb);
  93 }
  94
  95 static uint64_t timerblock_read(void *opaque, hwaddr addr,
  96                                 unsigned size)
  97 {
  98     timerblock *tb = (timerblock *)opaque;
  99     int64_t val;
 100     switch (addr) {
 101     case 0: /* Load */
 102         return tb->load;
 103     case 4: /* Counter.  */
 104         if (((tb->control & 1) == 0) || (tb->count == 0)) {
 105             return 0;
 106         }
 107         /* Slow and ugly, but hopefully won't happen too often.  */
 108         val = tb->tick - qemu_get_clock_ns(vm_clock);
 109         val /= timerblock_scale(tb);
 110         if (val < 0) {
 111             val = 0;
 112         }
 113         return val;
 114     case 8: /* Control.  */
 115         return tb->control;
 116     case 12: /* Interrupt status.  */
 117         return tb->status;
 118     default:
 119         return 0;
 120     }
 121 }
 122
 123 static void timerblock_write(void *opaque, hwaddr addr,
 124                              uint64_t value, unsigned size)
 125 {
 126     timerblock *tb = (timerblock *)opaque;
 127     int64_t old;
 128     switch (addr) {
 129     case 0: /* Load */
 130         tb->load = value;
 131         /* Fall through.  */
 132     case 4: /* Counter.  */
 133         if ((tb->control & 1) && tb->count) {
 134             /* Cancel the previous timer.  */
 135             qemu_del_timer(tb->timer);
 136         }
 137         tb->count = value;
 138         if (tb->control & 1) {
 139             timerblock_reload(tb, 1);
 140         }
 141         break;
 142     case 8: /* Control.  */
 143         old = tb->control;
 144         tb->control = value;
 145         if (((old & 1) == 0) && (value & 1)) {
 146             if (tb->count == 0 && (tb->control & 2)) {
 147                 tb->count = tb->load;
 148             }
 149             timerblock_reload(tb, 1);
 150         }
 151         break;
 152     case 12: /* Interrupt status.  */
 153         tb->status &= ~value;
 154         timerblock_update_irq(tb);
 155         break;
 156     }
 157 }
 158
 159 /* Wrapper functions to implement the "read timer/watchdog for
 160  * the current CPU" memory regions.
 161  */
 162 static uint64_t arm_thistimer_read(void *opaque, hwaddr addr,
 163                                    unsigned size)
 164 {
 165     arm_mptimer_state *s = (arm_mptimer_state *)opaque;
 166     int id = get_current_cpu(s);
 167     return timerblock_read(&s->timerblock[id * 2], addr, size);
 168 }
 169
 170 static void arm_thistimer_write(void *opaque, hwaddr addr,
 171                                 uint64_t value, unsigned size)
 172 {
 173     arm_mptimer_state *s = (arm_mptimer_state *)opaque;
 174     int id = get_current_cpu(s);
 175     timerblock_write(&s->timerblock[id * 2], addr, value, size);
 176 }
 177
 178 static uint64_t arm_thiswdog_read(void *opaque, hwaddr addr,
 179                                   unsigned size)
 180 {
 181     arm_mptimer_state *s = (arm_mptimer_state *)opaque;
 182     int id = get_current_cpu(s);
 183     return timerblock_read(&s->timerblock[id * 2 + 1], addr, size);
 184 }
 185
 186 static void arm_thiswdog_write(void *opaque, hwaddr addr,
 187                                uint64_t value, unsigned size)
 188 {
 189     arm_mptimer_state *s = (arm_mptimer_state *)opaque;
 190     int id = get_current_cpu(s);
 191     timerblock_write(&s->timerblock[id * 2 + 1], addr, value, size);
 192 }
 193
 194 static const MemoryRegionOps arm_thistimer_ops = {
 195     .read = arm_thistimer_read,
 196     .write = arm_thistimer_write,
 197     .valid = {
 198         .min_access_size = 4,
 199         .max_access_size = 4,
 200     },
 201     .endianness = DEVICE_NATIVE_ENDIAN,
 202 };
 203
 204 static const MemoryRegionOps arm_thiswdog_ops = {
 205     .read = arm_thiswdog_read,
 206     .write = arm_thiswdog_write,
 207     .valid = {
 208         .min_access_size = 4,
 209         .max_access_size = 4,
 210     },
 211     .endianness = DEVICE_NATIVE_ENDIAN,
 212 };
 213
 214 static const MemoryRegionOps timerblock_ops = {
 215     .read = timerblock_read,
 216     .write = timerblock_write,
 217     .valid = {
 218         .min_access_size = 4,
 219         .max_access_size = 4,
 220     },
 221     .endianness = DEVICE_NATIVE_ENDIAN,
 222 };
 223
 224 static void timerblock_reset(timerblock *tb)
 225 {
 226     tb->count = 0;
 227     tb->load = 0;
 228     tb->control = 0;
 229     tb->status = 0;
 230     tb->tick = 0;
 231     if (tb->timer) {
 232         qemu_del_timer(tb->timer);
 233     }
 234 }
 235
 236 static void arm_mptimer_reset(DeviceState *dev)
 237 {
 238     arm_mptimer_state *s =
 239         FROM_SYSBUS(arm_mptimer_state, sysbus_from_qdev(dev));
 240     int i;
 241     /* We reset every timer in the array, not just the ones we're using,
 242      * because vmsave will look at every array element.
 243      */
 244     for (i = 0; i < ARRAY_SIZE(s->timerblock); i++) {
 245         timerblock_reset(&s->timerblock[i]);
 246     }
 247 }
 248
 249 static int arm_mptimer_init(SysBusDevice *dev)
 250 {
 251     arm_mptimer_state *s = FROM_SYSBUS(arm_mptimer_state, dev);
 252     int i;
 253     if (s->num_cpu < 1 || s->num_cpu > MAX_CPUS) {
 254         hw_error("%s: num-cpu must be between 1 and %d\n", __func__, MAX_CPUS);
 255     }
 256     /* We implement one timer and one watchdog block per CPU, and
 257      * expose multiple MMIO regions:
 258      *  * region 0 is "timer for this core"
 259      *  * region 1 is "watchdog for this core"
 260      *  * region 2 is "timer for core 0"
 261      *  * region 3 is "watchdog for core 0"
 262      *  * region 4 is "timer for core 1"
 263      *  * region 5 is "watchdog for core 1"
 264      * and so on.
 265      * The outgoing interrupt lines are
 266      *  * timer for core 0
 267      *  * watchdog for core 0
 268      *  * timer for core 1
 269      *  * watchdog for core 1
 270      * and so on.
 271      */
 272     memory_region_init_io(&s->iomem[0], &arm_thistimer_ops, s,
 273                           "arm_mptimer_timer", 0x20);
 274     sysbus_init_mmio(dev, &s->iomem[0]);
 275     memory_region_init_io(&s->iomem[1], &arm_thiswdog_ops, s,
 276                           "arm_mptimer_wdog", 0x20);
 277     sysbus_init_mmio(dev, &s->iomem[1]);
 278     for (i = 0; i < (s->num_cpu * 2); i++) {
 279         timerblock *tb = &s->timerblock[i];
 280         tb->timer = qemu_new_timer_ns(vm_clock, timerblock_tick, tb);
 281         sysbus_init_irq(dev, &tb->irq);
 282         memory_region_init_io(&tb->iomem, &timerblock_ops, tb,
 283                               "arm_mptimer_timerblock", 0x20);
 284         sysbus_init_mmio(dev, &tb->iomem);
 285     }
 286
 287     return 0;
 288 }
 289
 290 static const VMStateDescription vmstate_timerblock = {
 291     .name = "arm_mptimer_timerblock",
 292     .version_id = 1,
 293     .minimum_version_id = 1,
 294     .fields = (VMStateField[]) {
 295         VMSTATE_UINT32(count, timerblock),
 296         VMSTATE_UINT32(load, timerblock),
 297         VMSTATE_UINT32(control, timerblock),
 298         VMSTATE_UINT32(status, timerblock),
 299         VMSTATE_INT64(tick, timerblock),
 300         VMSTATE_END_OF_LIST()
 301     }
 302 };
 303
 304 static const VMStateDescription vmstate_arm_mptimer = {
 305     .name = "arm_mptimer",
 306     .version_id = 1,
 307     .minimum_version_id = 1,
 308     .fields = (VMStateField[]) {
 309         VMSTATE_STRUCT_ARRAY(timerblock, arm_mptimer_state, (MAX_CPUS * 2),
 310                              1, vmstate_timerblock, timerblock),
 311         VMSTATE_END_OF_LIST()
 312     }
 313 };
 314
 315 static Property arm_mptimer_properties[] = {
 316     DEFINE_PROP_UINT32("num-cpu", arm_mptimer_state, num_cpu, 0),
 317     DEFINE_PROP_END_OF_LIST()
 318 };
 319
 320 static void arm_mptimer_class_init(ObjectClass *klass, void *data)
 321 {
 322     DeviceClass *dc = DEVICE_CLASS(klass);
 323     SysBusDeviceClass *sbc = SYS_BUS_DEVICE_CLASS(klass);
 324
 325     sbc->init = arm_mptimer_init;
 326     dc->vmsd = &vmstate_arm_mptimer;
 327     dc->reset = arm_mptimer_reset;
 328     dc->no_user = 1;
 329     dc->props = arm_mptimer_properties;
 330 }
 331
 332 static TypeInfo arm_mptimer_info = {
 333     .name          = "arm_mptimer",
 334     .parent        = TYPE_SYS_BUS_DEVICE,
 335     .instance_size = sizeof(arm_mptimer_state),
 336     .class_init    = arm_mptimer_class_init,
 337 };
 338
 339 static void arm_mptimer_register_types(void)
 340 {
 341     type_register_static(&arm_mptimer_info);
 342 }
 343
 344 type_init(arm_mptimer_register_types)