hw/milkymist-sysctl.c

   1 /*
   2  *  QEMU model of the Milkymist System Controller.
   3  *
   4  *  Copyright (c) 2010-2012 Michael Walle <michael@walle.cc>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  *
  19  *
  20  * Specification available at:
  21  *   http://www.milkymist.org/socdoc/sysctl.pdf
  22  */
  23
  24 #include "hw.h"
  25 #include "sysbus.h"
  26 #include "sysemu/sysemu.h"
  27 #include "trace.h"
  28 #include "qemu/timer.h"
  29 #include "ptimer.h"
  30 #include "qemu/error-report.h"
  31
  32 enum {
  33     CTRL_ENABLE      = (1<<0),
  34     CTRL_AUTORESTART = (1<<1),
  35 };
  36
  37 enum {
  38     ICAP_READY       = (1<<0),
  39 };
  40
  41 enum {
  42     R_GPIO_IN         = 0,
  43     R_GPIO_OUT,
  44     R_GPIO_INTEN,
  45     R_TIMER0_CONTROL  = 4,
  46     R_TIMER0_COMPARE,
  47     R_TIMER0_COUNTER,
  48     R_TIMER1_CONTROL  = 8,
  49     R_TIMER1_COMPARE,
  50     R_TIMER1_COUNTER,
  51     R_ICAP = 16,
  52     R_DBG_SCRATCHPAD  = 20,
  53     R_DBG_WRITE_LOCK,
  54     R_CLK_FREQUENCY   = 29,
  55     R_CAPABILITIES,
  56     R_SYSTEM_ID,
  57     R_MAX
  58 };
  59
  60 struct MilkymistSysctlState {
  61     SysBusDevice busdev;
  62     MemoryRegion regs_region;
  63
  64     QEMUBH *bh0;
  65     QEMUBH *bh1;
  66     ptimer_state *ptimer0;
  67     ptimer_state *ptimer1;
  68
  69     uint32_t freq_hz;
  70     uint32_t capabilities;
  71     uint32_t systemid;
  72     uint32_t strappings;
  73
  74     uint32_t regs[R_MAX];
  75
  76     qemu_irq gpio_irq;
  77     qemu_irq timer0_irq;
  78     qemu_irq timer1_irq;
  79 };
  80 typedef struct MilkymistSysctlState MilkymistSysctlState;
  81
  82 static void sysctl_icap_write(MilkymistSysctlState *s, uint32_t value)
  83 {
  84     trace_milkymist_sysctl_icap_write(value);
  85     switch (value & 0xffff) {
  86     case 0x000e:
  87         qemu_system_shutdown_request();
  88         break;
  89     }
  90 }
  91
  92 static uint64_t sysctl_read(void *opaque, hwaddr addr,
  93                             unsigned size)
  94 {
  95     MilkymistSysctlState *s = opaque;
  96     uint32_t r = 0;
  97
  98     addr >>= 2;
  99     switch (addr) {
 100     case R_TIMER0_COUNTER:
 101         r = (uint32_t)ptimer_get_count(s->ptimer0);
 102         /* milkymist timer counts up */
 103         r = s->regs[R_TIMER0_COMPARE] - r;
 104         break;
 105     case R_TIMER1_COUNTER:
 106         r = (uint32_t)ptimer_get_count(s->ptimer1);
 107         /* milkymist timer counts up */
 108         r = s->regs[R_TIMER1_COMPARE] - r;
 109         break;
 110     case R_GPIO_IN:
 111     case R_GPIO_OUT:
 112     case R_GPIO_INTEN:
 113     case R_TIMER0_CONTROL:
 114     case R_TIMER0_COMPARE:
 115     case R_TIMER1_CONTROL:
 116     case R_TIMER1_COMPARE:
 117     case R_ICAP:
 118     case R_DBG_SCRATCHPAD:
 119     case R_DBG_WRITE_LOCK:
 120     case R_CLK_FREQUENCY:
 121     case R_CAPABILITIES:
 122     case R_SYSTEM_ID:
 123         r = s->regs[addr];
 124         break;
 125
 126     default:
 127         error_report("milkymist_sysctl: read access to unknown register 0x"
 128                 TARGET_FMT_plx, addr << 2);
 129         break;
 130     }
 131
 132     trace_milkymist_sysctl_memory_read(addr << 2, r);
 133
 134     return r;
 135 }
 136
 137 static void sysctl_write(void *opaque, hwaddr addr, uint64_t value,
 138                          unsigned size)
 139 {
 140     MilkymistSysctlState *s = opaque;
 141
 142     trace_milkymist_sysctl_memory_write(addr, value);
 143
 144     addr >>= 2;
 145     switch (addr) {
 146     case R_GPIO_OUT:
 147     case R_GPIO_INTEN:
 148     case R_TIMER0_COUNTER:
 149     case R_TIMER1_COUNTER:
 150     case R_DBG_SCRATCHPAD:
 151         s->regs[addr] = value;
 152         break;
 153     case R_TIMER0_COMPARE:
 154         ptimer_set_limit(s->ptimer0, value, 0);
 155         s->regs[addr] = value;
 156         break;
 157     case R_TIMER1_COMPARE:
 158         ptimer_set_limit(s->ptimer1, value, 0);
 159         s->regs[addr] = value;
 160         break;
 161     case R_TIMER0_CONTROL:
 162         s->regs[addr] = value;
 163         if (s->regs[R_TIMER0_CONTROL] & CTRL_ENABLE) {
 164             trace_milkymist_sysctl_start_timer0();
 165             ptimer_set_count(s->ptimer0,
 166                     s->regs[R_TIMER0_COMPARE] - s->regs[R_TIMER0_COUNTER]);
 167             ptimer_run(s->ptimer0, 0);
 168         } else {
 169             trace_milkymist_sysctl_stop_timer0();
 170             ptimer_stop(s->ptimer0);
 171         }
 172         break;
 173     case R_TIMER1_CONTROL:
 174         s->regs[addr] = value;
 175         if (s->regs[R_TIMER1_CONTROL] & CTRL_ENABLE) {
 176             trace_milkymist_sysctl_start_timer1();
 177             ptimer_set_count(s->ptimer1,
 178                     s->regs[R_TIMER1_COMPARE] - s->regs[R_TIMER1_COUNTER]);
 179             ptimer_run(s->ptimer1, 0);
 180         } else {
 181             trace_milkymist_sysctl_stop_timer1();
 182             ptimer_stop(s->ptimer1);
 183         }
 184         break;
 185     case R_ICAP:
 186         sysctl_icap_write(s, value);
 187         break;
 188     case R_DBG_WRITE_LOCK:
 189         s->regs[addr] = 1;
 190         break;
 191     case R_SYSTEM_ID:
 192         qemu_system_reset_request();
 193         break;
 194
 195     case R_GPIO_IN:
 196     case R_CLK_FREQUENCY:
 197     case R_CAPABILITIES:
 198         error_report("milkymist_sysctl: write to read-only register 0x"
 199                 TARGET_FMT_plx, addr << 2);
 200         break;
 201
 202     default:
 203         error_report("milkymist_sysctl: write access to unknown register 0x"
 204                 TARGET_FMT_plx, addr << 2);
 205         break;
 206     }
 207 }
 208
 209 static const MemoryRegionOps sysctl_mmio_ops = {
 210     .read = sysctl_read,
 211     .write = sysctl_write,
 212     .valid = {
 213         .min_access_size = 4,
 214         .max_access_size = 4,
 215     },
 216     .endianness = DEVICE_NATIVE_ENDIAN,
 217 };
 218
 219 static void timer0_hit(void *opaque)
 220 {
 221     MilkymistSysctlState *s = opaque;
 222
 223     if (!(s->regs[R_TIMER0_CONTROL] & CTRL_AUTORESTART)) {
 224         s->regs[R_TIMER0_CONTROL] &= ~CTRL_ENABLE;
 225         trace_milkymist_sysctl_stop_timer0();
 226         ptimer_stop(s->ptimer0);
 227     }
 228
 229     trace_milkymist_sysctl_pulse_irq_timer0();
 230     qemu_irq_pulse(s->timer0_irq);
 231 }
 232
 233 static void timer1_hit(void *opaque)
 234 {
 235     MilkymistSysctlState *s = opaque;
 236
 237     if (!(s->regs[R_TIMER1_CONTROL] & CTRL_AUTORESTART)) {
 238         s->regs[R_TIMER1_CONTROL] &= ~CTRL_ENABLE;
 239         trace_milkymist_sysctl_stop_timer1();
 240         ptimer_stop(s->ptimer1);
 241     }
 242
 243     trace_milkymist_sysctl_pulse_irq_timer1();
 244     qemu_irq_pulse(s->timer1_irq);
 245 }
 246
 247 static void milkymist_sysctl_reset(DeviceState *d)
 248 {
 249     MilkymistSysctlState *s =
 250             container_of(d, MilkymistSysctlState, busdev.qdev);
 251     int i;
 252
 253     for (i = 0; i < R_MAX; i++) {
 254         s->regs[i] = 0;
 255     }
 256
 257     ptimer_stop(s->ptimer0);
 258     ptimer_stop(s->ptimer1);
 259
 260     /* defaults */
 261     s->regs[R_ICAP] = ICAP_READY;
 262     s->regs[R_SYSTEM_ID] = s->systemid;
 263     s->regs[R_CLK_FREQUENCY] = s->freq_hz;
 264     s->regs[R_CAPABILITIES] = s->capabilities;
 265     s->regs[R_GPIO_IN] = s->strappings;
 266 }
 267
 268 static int milkymist_sysctl_init(SysBusDevice *dev)
 269 {
 270     MilkymistSysctlState *s = FROM_SYSBUS(typeof(*s), dev);
 271
 272     sysbus_init_irq(dev, &s->gpio_irq);
 273     sysbus_init_irq(dev, &s->timer0_irq);
 274     sysbus_init_irq(dev, &s->timer1_irq);
 275
 276     s->bh0 = qemu_bh_new(timer0_hit, s);
 277     s->bh1 = qemu_bh_new(timer1_hit, s);
 278     s->ptimer0 = ptimer_init(s->bh0);
 279     s->ptimer1 = ptimer_init(s->bh1);
 280     ptimer_set_freq(s->ptimer0, s->freq_hz);
 281     ptimer_set_freq(s->ptimer1, s->freq_hz);
 282
 283     memory_region_init_io(&s->regs_region, &sysctl_mmio_ops, s,
 284             "milkymist-sysctl", R_MAX * 4);
 285     sysbus_init_mmio(dev, &s->regs_region);
 286
 287     return 0;
 288 }
 289
 290 static const VMStateDescription vmstate_milkymist_sysctl = {
 291     .name = "milkymist-sysctl",
 292     .version_id = 1,
 293     .minimum_version_id = 1,
 294     .minimum_version_id_old = 1,
 295     .fields      = (VMStateField[]) {
 296         VMSTATE_UINT32_ARRAY(regs, MilkymistSysctlState, R_MAX),
 297         VMSTATE_PTIMER(ptimer0, MilkymistSysctlState),
 298         VMSTATE_PTIMER(ptimer1, MilkymistSysctlState),
 299         VMSTATE_END_OF_LIST()
 300     }
 301 };
 302
 303 static Property milkymist_sysctl_properties[] = {
 304     DEFINE_PROP_UINT32("frequency", MilkymistSysctlState,
 305     freq_hz, 80000000),
 306     DEFINE_PROP_UINT32("capabilities", MilkymistSysctlState,
 307     capabilities, 0x00000000),
 308     DEFINE_PROP_UINT32("systemid", MilkymistSysctlState,
 309     systemid, 0x10014d31),
 310     DEFINE_PROP_UINT32("gpio_strappings", MilkymistSysctlState,
 311     strappings, 0x00000001),
 312     DEFINE_PROP_END_OF_LIST(),
 313 };
 314
 315 static void milkymist_sysctl_class_init(ObjectClass *klass, void *data)
 316 {
 317     DeviceClass *dc = DEVICE_CLASS(klass);
 318     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 319
 320     k->init = milkymist_sysctl_init;
 321     dc->reset = milkymist_sysctl_reset;
 322     dc->vmsd = &vmstate_milkymist_sysctl;
 323     dc->props = milkymist_sysctl_properties;
 324 }
 325
 326 static const TypeInfo milkymist_sysctl_info = {
 327     .name          = "milkymist-sysctl",
 328     .parent        = TYPE_SYS_BUS_DEVICE,
 329     .instance_size = sizeof(MilkymistSysctlState),
 330     .class_init    = milkymist_sysctl_class_init,
 331 };
 332
 333 static void milkymist_sysctl_register_types(void)
 334 {
 335     type_register_static(&milkymist_sysctl_info);
 336 }
 337
 338 type_init(milkymist_sysctl_register_types)