hw/timer/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 "qemu/osdep.h"
  25 #include "hw/hw.h"
  26 #include "hw/sysbus.h"
  27 #include "sysemu/sysemu.h"
  28 #include "trace.h"
  29 #include "qemu/timer.h"
  30 #include "hw/ptimer.h"
  31 #include "qemu/error-report.h"
  32
  33 enum {
  34     CTRL_ENABLE      = (1<<0),
  35     CTRL_AUTORESTART = (1<<1),
  36 };
  37
  38 enum {
  39     ICAP_READY       = (1<<0),
  40 };
  41
  42 enum {
  43     R_GPIO_IN         = 0,
  44     R_GPIO_OUT,
  45     R_GPIO_INTEN,
  46     R_TIMER0_CONTROL  = 4,
  47     R_TIMER0_COMPARE,
  48     R_TIMER0_COUNTER,
  49     R_TIMER1_CONTROL  = 8,
  50     R_TIMER1_COMPARE,
  51     R_TIMER1_COUNTER,
  52     R_ICAP = 16,
  53     R_DBG_SCRATCHPAD  = 20,
  54     R_DBG_WRITE_LOCK,
  55     R_CLK_FREQUENCY   = 29,
  56     R_CAPABILITIES,
  57     R_SYSTEM_ID,
  58     R_MAX
  59 };
  60
  61 #define TYPE_MILKYMIST_SYSCTL "milkymist-sysctl"
  62 #define MILKYMIST_SYSCTL(obj) \
  63     OBJECT_CHECK(MilkymistSysctlState, (obj), TYPE_MILKYMIST_SYSCTL)
  64
  65 struct MilkymistSysctlState {
  66     SysBusDevice parent_obj;
  67
  68     MemoryRegion regs_region;
  69
  70     QEMUBH *bh0;
  71     QEMUBH *bh1;
  72     ptimer_state *ptimer0;
  73     ptimer_state *ptimer1;
  74
  75     uint32_t freq_hz;
  76     uint32_t capabilities;
  77     uint32_t systemid;
  78     uint32_t strappings;
  79
  80     uint32_t regs[R_MAX];
  81
  82     qemu_irq gpio_irq;
  83     qemu_irq timer0_irq;
  84     qemu_irq timer1_irq;
  85 };
  86 typedef struct MilkymistSysctlState MilkymistSysctlState;
  87
  88 static void sysctl_icap_write(MilkymistSysctlState *s, uint32_t value)
  89 {
  90     trace_milkymist_sysctl_icap_write(value);
  91     switch (value & 0xffff) {
  92     case 0x000e:
  93         qemu_system_shutdown_request();
  94         break;
  95     }
  96 }
  97
  98 static uint64_t sysctl_read(void *opaque, hwaddr addr,
  99                             unsigned size)
 100 {
 101     MilkymistSysctlState *s = opaque;
 102     uint32_t r = 0;
 103
 104     addr >>= 2;
 105     switch (addr) {
 106     case R_TIMER0_COUNTER:
 107         r = (uint32_t)ptimer_get_count(s->ptimer0);
 108         /* milkymist timer counts up */
 109         r = s->regs[R_TIMER0_COMPARE] - r;
 110         break;
 111     case R_TIMER1_COUNTER:
 112         r = (uint32_t)ptimer_get_count(s->ptimer1);
 113         /* milkymist timer counts up */
 114         r = s->regs[R_TIMER1_COMPARE] - r;
 115         break;
 116     case R_GPIO_IN:
 117     case R_GPIO_OUT:
 118     case R_GPIO_INTEN:
 119     case R_TIMER0_CONTROL:
 120     case R_TIMER0_COMPARE:
 121     case R_TIMER1_CONTROL:
 122     case R_TIMER1_COMPARE:
 123     case R_ICAP:
 124     case R_DBG_SCRATCHPAD:
 125     case R_DBG_WRITE_LOCK:
 126     case R_CLK_FREQUENCY:
 127     case R_CAPABILITIES:
 128     case R_SYSTEM_ID:
 129         r = s->regs[addr];
 130         break;
 131
 132     default:
 133         error_report("milkymist_sysctl: read access to unknown register 0x"
 134                 TARGET_FMT_plx, addr << 2);
 135         break;
 136     }
 137
 138     trace_milkymist_sysctl_memory_read(addr << 2, r);
 139
 140     return r;
 141 }
 142
 143 static void sysctl_write(void *opaque, hwaddr addr, uint64_t value,
 144                          unsigned size)
 145 {
 146     MilkymistSysctlState *s = opaque;
 147
 148     trace_milkymist_sysctl_memory_write(addr, value);
 149
 150     addr >>= 2;
 151     switch (addr) {
 152     case R_GPIO_OUT:
 153     case R_GPIO_INTEN:
 154     case R_TIMER0_COUNTER:
 155     case R_TIMER1_COUNTER:
 156     case R_DBG_SCRATCHPAD:
 157         s->regs[addr] = value;
 158         break;
 159     case R_TIMER0_COMPARE:
 160         ptimer_set_limit(s->ptimer0, value, 0);
 161         s->regs[addr] = value;
 162         break;
 163     case R_TIMER1_COMPARE:
 164         ptimer_set_limit(s->ptimer1, value, 0);
 165         s->regs[addr] = value;
 166         break;
 167     case R_TIMER0_CONTROL:
 168         s->regs[addr] = value;
 169         if (s->regs[R_TIMER0_CONTROL] & CTRL_ENABLE) {
 170             trace_milkymist_sysctl_start_timer0();
 171             ptimer_set_count(s->ptimer0,
 172                     s->regs[R_TIMER0_COMPARE] - s->regs[R_TIMER0_COUNTER]);
 173             ptimer_run(s->ptimer0, 0);
 174         } else {
 175             trace_milkymist_sysctl_stop_timer0();
 176             ptimer_stop(s->ptimer0);
 177         }
 178         break;
 179     case R_TIMER1_CONTROL:
 180         s->regs[addr] = value;
 181         if (s->regs[R_TIMER1_CONTROL] & CTRL_ENABLE) {
 182             trace_milkymist_sysctl_start_timer1();
 183             ptimer_set_count(s->ptimer1,
 184                     s->regs[R_TIMER1_COMPARE] - s->regs[R_TIMER1_COUNTER]);
 185             ptimer_run(s->ptimer1, 0);
 186         } else {
 187             trace_milkymist_sysctl_stop_timer1();
 188             ptimer_stop(s->ptimer1);
 189         }
 190         break;
 191     case R_ICAP:
 192         sysctl_icap_write(s, value);
 193         break;
 194     case R_DBG_WRITE_LOCK:
 195         s->regs[addr] = 1;
 196         break;
 197     case R_SYSTEM_ID:
 198         qemu_system_reset_request();
 199         break;
 200
 201     case R_GPIO_IN:
 202     case R_CLK_FREQUENCY:
 203     case R_CAPABILITIES:
 204         error_report("milkymist_sysctl: write to read-only register 0x"
 205                 TARGET_FMT_plx, addr << 2);
 206         break;
 207
 208     default:
 209         error_report("milkymist_sysctl: write access to unknown register 0x"
 210                 TARGET_FMT_plx, addr << 2);
 211         break;
 212     }
 213 }
 214
 215 static const MemoryRegionOps sysctl_mmio_ops = {
 216     .read = sysctl_read,
 217     .write = sysctl_write,
 218     .valid = {
 219         .min_access_size = 4,
 220         .max_access_size = 4,
 221     },
 222     .endianness = DEVICE_NATIVE_ENDIAN,
 223 };
 224
 225 static void timer0_hit(void *opaque)
 226 {
 227     MilkymistSysctlState *s = opaque;
 228
 229     if (!(s->regs[R_TIMER0_CONTROL] & CTRL_AUTORESTART)) {
 230         s->regs[R_TIMER0_CONTROL] &= ~CTRL_ENABLE;
 231         trace_milkymist_sysctl_stop_timer0();
 232         ptimer_stop(s->ptimer0);
 233     }
 234
 235     trace_milkymist_sysctl_pulse_irq_timer0();
 236     qemu_irq_pulse(s->timer0_irq);
 237 }
 238
 239 static void timer1_hit(void *opaque)
 240 {
 241     MilkymistSysctlState *s = opaque;
 242
 243     if (!(s->regs[R_TIMER1_CONTROL] & CTRL_AUTORESTART)) {
 244         s->regs[R_TIMER1_CONTROL] &= ~CTRL_ENABLE;
 245         trace_milkymist_sysctl_stop_timer1();
 246         ptimer_stop(s->ptimer1);
 247     }
 248
 249     trace_milkymist_sysctl_pulse_irq_timer1();
 250     qemu_irq_pulse(s->timer1_irq);
 251 }
 252
 253 static void milkymist_sysctl_reset(DeviceState *d)
 254 {
 255     MilkymistSysctlState *s = MILKYMIST_SYSCTL(d);
 256     int i;
 257
 258     for (i = 0; i < R_MAX; i++) {
 259         s->regs[i] = 0;
 260     }
 261
 262     ptimer_stop(s->ptimer0);
 263     ptimer_stop(s->ptimer1);
 264
 265     /* defaults */
 266     s->regs[R_ICAP] = ICAP_READY;
 267     s->regs[R_SYSTEM_ID] = s->systemid;
 268     s->regs[R_CLK_FREQUENCY] = s->freq_hz;
 269     s->regs[R_CAPABILITIES] = s->capabilities;
 270     s->regs[R_GPIO_IN] = s->strappings;
 271 }
 272
 273 static int milkymist_sysctl_init(SysBusDevice *dev)
 274 {
 275     MilkymistSysctlState *s = MILKYMIST_SYSCTL(dev);
 276
 277     sysbus_init_irq(dev, &s->gpio_irq);
 278     sysbus_init_irq(dev, &s->timer0_irq);
 279     sysbus_init_irq(dev, &s->timer1_irq);
 280
 281     s->bh0 = qemu_bh_new(timer0_hit, s);
 282     s->bh1 = qemu_bh_new(timer1_hit, s);
 283     s->ptimer0 = ptimer_init(s->bh0);
 284     s->ptimer1 = ptimer_init(s->bh1);
 285     ptimer_set_freq(s->ptimer0, s->freq_hz);
 286     ptimer_set_freq(s->ptimer1, s->freq_hz);
 287
 288     memory_region_init_io(&s->regs_region, OBJECT(s), &sysctl_mmio_ops, s,
 289             "milkymist-sysctl", R_MAX * 4);
 290     sysbus_init_mmio(dev, &s->regs_region);
 291
 292     return 0;
 293 }
 294
 295 static const VMStateDescription vmstate_milkymist_sysctl = {
 296     .name = "milkymist-sysctl",
 297     .version_id = 1,
 298     .minimum_version_id = 1,
 299     .fields = (VMStateField[]) {
 300         VMSTATE_UINT32_ARRAY(regs, MilkymistSysctlState, R_MAX),
 301         VMSTATE_PTIMER(ptimer0, MilkymistSysctlState),
 302         VMSTATE_PTIMER(ptimer1, MilkymistSysctlState),
 303         VMSTATE_END_OF_LIST()
 304     }
 305 };
 306
 307 static Property milkymist_sysctl_properties[] = {
 308     DEFINE_PROP_UINT32("frequency", MilkymistSysctlState,
 309     freq_hz, 80000000),
 310     DEFINE_PROP_UINT32("capabilities", MilkymistSysctlState,
 311     capabilities, 0x00000000),
 312     DEFINE_PROP_UINT32("systemid", MilkymistSysctlState,
 313     systemid, 0x10014d31),
 314     DEFINE_PROP_UINT32("gpio_strappings", MilkymistSysctlState,
 315     strappings, 0x00000001),
 316     DEFINE_PROP_END_OF_LIST(),
 317 };
 318
 319 static void milkymist_sysctl_class_init(ObjectClass *klass, void *data)
 320 {
 321     DeviceClass *dc = DEVICE_CLASS(klass);
 322     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 323
 324     k->init = milkymist_sysctl_init;
 325     dc->reset = milkymist_sysctl_reset;
 326     dc->vmsd = &vmstate_milkymist_sysctl;
 327     dc->props = milkymist_sysctl_properties;
 328 }
 329
 330 static const TypeInfo milkymist_sysctl_info = {
 331     .name          = TYPE_MILKYMIST_SYSCTL,
 332     .parent        = TYPE_SYS_BUS_DEVICE,
 333     .instance_size = sizeof(MilkymistSysctlState),
 334     .class_init    = milkymist_sysctl_class_init,
 335 };
 336
 337 static void milkymist_sysctl_register_types(void)
 338 {
 339     type_register_static(&milkymist_sysctl_info);
 340 }
 341
 342 type_init(milkymist_sysctl_register_types)