hw/milkymist-sysctl.c

   1 /*
   2  *  QEMU model of the Milkymist System Controller.
   3  *
   4  *  Copyright (c) 2010 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.h"
  27 #include "trace.h"
  28 #include "qemu-timer.h"
  29 #include "qemu-error.h"
  30
  31 enum {
  32     CTRL_ENABLE      = (1<<0),
  33     CTRL_AUTORESTART = (1<<1),
  34 };
  35
  36 enum {
  37     ICAP_READY       = (1<<0),
  38 };
  39
  40 enum {
  41     R_GPIO_IN = 0,
  42     R_GPIO_OUT,
  43     R_GPIO_INTEN,
  44     R_RESERVED0,
  45     R_TIMER0_CONTROL,
  46     R_TIMER0_COMPARE,
  47     R_TIMER0_COUNTER,
  48     R_RESERVED1,
  49     R_TIMER1_CONTROL,
  50     R_TIMER1_COMPARE,
  51     R_TIMER1_COUNTER,
  52     R_RESERVED2,
  53     R_RESERVED3,
  54     R_ICAP,
  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, target_phys_addr_t 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_CAPABILITIES:
 119     case R_SYSTEM_ID:
 120         r = s->regs[addr];
 121         break;
 122
 123     default:
 124         error_report("milkymist_sysctl: read access to unknown register 0x"
 125                 TARGET_FMT_plx, addr << 2);
 126         break;
 127     }
 128
 129     trace_milkymist_sysctl_memory_read(addr << 2, r);
 130
 131     return r;
 132 }
 133
 134 static void sysctl_write(void *opaque, target_phys_addr_t addr, uint64_t value,
 135                          unsigned size)
 136 {
 137     MilkymistSysctlState *s = opaque;
 138
 139     trace_milkymist_sysctl_memory_write(addr, value);
 140
 141     addr >>= 2;
 142     switch (addr) {
 143     case R_GPIO_OUT:
 144     case R_GPIO_INTEN:
 145     case R_TIMER0_COUNTER:
 146     case R_TIMER1_COUNTER:
 147         s->regs[addr] = value;
 148         break;
 149     case R_TIMER0_COMPARE:
 150         ptimer_set_limit(s->ptimer0, value, 0);
 151         s->regs[addr] = value;
 152         break;
 153     case R_TIMER1_COMPARE:
 154         ptimer_set_limit(s->ptimer1, value, 0);
 155         s->regs[addr] = value;
 156         break;
 157     case R_TIMER0_CONTROL:
 158         s->regs[addr] = value;
 159         if (s->regs[R_TIMER0_CONTROL] & CTRL_ENABLE) {
 160             trace_milkymist_sysctl_start_timer0();
 161             ptimer_set_count(s->ptimer0,
 162                     s->regs[R_TIMER0_COMPARE] - s->regs[R_TIMER0_COUNTER]);
 163             ptimer_run(s->ptimer0, 0);
 164         } else {
 165             trace_milkymist_sysctl_stop_timer0();
 166             ptimer_stop(s->ptimer0);
 167         }
 168         break;
 169     case R_TIMER1_CONTROL:
 170         s->regs[addr] = value;
 171         if (s->regs[R_TIMER1_CONTROL] & CTRL_ENABLE) {
 172             trace_milkymist_sysctl_start_timer1();
 173             ptimer_set_count(s->ptimer1,
 174                     s->regs[R_TIMER1_COMPARE] - s->regs[R_TIMER1_COUNTER]);
 175             ptimer_run(s->ptimer1, 0);
 176         } else {
 177             trace_milkymist_sysctl_stop_timer1();
 178             ptimer_stop(s->ptimer1);
 179         }
 180         break;
 181     case R_ICAP:
 182         sysctl_icap_write(s, value);
 183         break;
 184     case R_SYSTEM_ID:
 185         qemu_system_reset_request();
 186         break;
 187
 188     case R_GPIO_IN:
 189     case R_CAPABILITIES:
 190         error_report("milkymist_sysctl: write to read-only register 0x"
 191                 TARGET_FMT_plx, addr << 2);
 192         break;
 193
 194     default:
 195         error_report("milkymist_sysctl: write access to unknown register 0x"
 196                 TARGET_FMT_plx, addr << 2);
 197         break;
 198     }
 199 }
 200
 201 static const MemoryRegionOps sysctl_mmio_ops = {
 202     .read = sysctl_read,
 203     .write = sysctl_write,
 204     .valid = {
 205         .min_access_size = 4,
 206         .max_access_size = 4,
 207     },
 208     .endianness = DEVICE_NATIVE_ENDIAN,
 209 };
 210
 211 static void timer0_hit(void *opaque)
 212 {
 213     MilkymistSysctlState *s = opaque;
 214
 215     if (!(s->regs[R_TIMER0_CONTROL] & CTRL_AUTORESTART)) {
 216         s->regs[R_TIMER0_CONTROL] &= ~CTRL_ENABLE;
 217         trace_milkymist_sysctl_stop_timer0();
 218         ptimer_stop(s->ptimer0);
 219     }
 220
 221     trace_milkymist_sysctl_pulse_irq_timer0();
 222     qemu_irq_pulse(s->timer0_irq);
 223 }
 224
 225 static void timer1_hit(void *opaque)
 226 {
 227     MilkymistSysctlState *s = opaque;
 228
 229     if (!(s->regs[R_TIMER1_CONTROL] & CTRL_AUTORESTART)) {
 230         s->regs[R_TIMER1_CONTROL] &= ~CTRL_ENABLE;
 231         trace_milkymist_sysctl_stop_timer1();
 232         ptimer_stop(s->ptimer1);
 233     }
 234
 235     trace_milkymist_sysctl_pulse_irq_timer1();
 236     qemu_irq_pulse(s->timer1_irq);
 237 }
 238
 239 static void milkymist_sysctl_reset(DeviceState *d)
 240 {
 241     MilkymistSysctlState *s =
 242             container_of(d, MilkymistSysctlState, busdev.qdev);
 243     int i;
 244
 245     for (i = 0; i < R_MAX; i++) {
 246         s->regs[i] = 0;
 247     }
 248
 249     ptimer_stop(s->ptimer0);
 250     ptimer_stop(s->ptimer1);
 251
 252     /* defaults */
 253     s->regs[R_ICAP] = ICAP_READY;
 254     s->regs[R_SYSTEM_ID] = s->systemid;
 255     s->regs[R_CAPABILITIES] = s->capabilities;
 256     s->regs[R_GPIO_IN] = s->strappings;
 257 }
 258
 259 static int milkymist_sysctl_init(SysBusDevice *dev)
 260 {
 261     MilkymistSysctlState *s = FROM_SYSBUS(typeof(*s), dev);
 262
 263     sysbus_init_irq(dev, &s->gpio_irq);
 264     sysbus_init_irq(dev, &s->timer0_irq);
 265     sysbus_init_irq(dev, &s->timer1_irq);
 266
 267     s->bh0 = qemu_bh_new(timer0_hit, s);
 268     s->bh1 = qemu_bh_new(timer1_hit, s);
 269     s->ptimer0 = ptimer_init(s->bh0);
 270     s->ptimer1 = ptimer_init(s->bh1);
 271     ptimer_set_freq(s->ptimer0, s->freq_hz);
 272     ptimer_set_freq(s->ptimer1, s->freq_hz);
 273
 274     memory_region_init_io(&s->regs_region, &sysctl_mmio_ops, s,
 275             "milkymist-sysctl", R_MAX * 4);
 276     sysbus_init_mmio(dev, &s->regs_region);
 277
 278     return 0;
 279 }
 280
 281 static const VMStateDescription vmstate_milkymist_sysctl = {
 282     .name = "milkymist-sysctl",
 283     .version_id = 1,
 284     .minimum_version_id = 1,
 285     .minimum_version_id_old = 1,
 286     .fields      = (VMStateField[]) {
 287         VMSTATE_UINT32_ARRAY(regs, MilkymistSysctlState, R_MAX),
 288         VMSTATE_PTIMER(ptimer0, MilkymistSysctlState),
 289         VMSTATE_PTIMER(ptimer1, MilkymistSysctlState),
 290         VMSTATE_END_OF_LIST()
 291     }
 292 };
 293
 294 static SysBusDeviceInfo milkymist_sysctl_info = {
 295     .init = milkymist_sysctl_init,
 296     .qdev.name  = "milkymist-sysctl",
 297     .qdev.size  = sizeof(MilkymistSysctlState),
 298     .qdev.vmsd  = &vmstate_milkymist_sysctl,
 299     .qdev.reset = milkymist_sysctl_reset,
 300     .qdev.props = (Property[]) {
 301         DEFINE_PROP_UINT32("frequency", MilkymistSysctlState,
 302                 freq_hz, 80000000),
 303         DEFINE_PROP_UINT32("capabilities", MilkymistSysctlState,
 304                 capabilities, 0x00000000),
 305         DEFINE_PROP_UINT32("systemid", MilkymistSysctlState,
 306                 systemid, 0x10014d31),
 307         DEFINE_PROP_UINT32("gpio_strappings", MilkymistSysctlState,
 308                 strappings, 0x00000001),
 309         DEFINE_PROP_END_OF_LIST(),
 310     }
 311 };
 312
 313 static void milkymist_sysctl_register(void)
 314 {
 315     sysbus_register_withprop(&milkymist_sysctl_info);
 316 }
 317
 318 device_init(milkymist_sysctl_register)