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
  63     QEMUBH *bh0;
  64     QEMUBH *bh1;
  65     ptimer_state *ptimer0;
  66     ptimer_state *ptimer1;
  67
  68     uint32_t freq_hz;
  69     uint32_t capabilities;
  70     uint32_t systemid;
  71     uint32_t strappings;
  72
  73     uint32_t regs[R_MAX];
  74
  75     qemu_irq gpio_irq;
  76     qemu_irq timer0_irq;
  77     qemu_irq timer1_irq;
  78 };
  79 typedef struct MilkymistSysctlState MilkymistSysctlState;
  80
  81 static void sysctl_icap_write(MilkymistSysctlState *s, uint32_t value)
  82 {
  83     trace_milkymist_sysctl_icap_write(value);
  84     switch (value & 0xffff) {
  85     case 0x000e:
  86         qemu_system_shutdown_request();
  87         break;
  88     }
  89 }
  90
  91 static uint32_t sysctl_read(void *opaque, target_phys_addr_t addr)
  92 {
  93     MilkymistSysctlState *s = opaque;
  94     uint32_t r = 0;
  95
  96     addr >>= 2;
  97     switch (addr) {
  98     case R_TIMER0_COUNTER:
  99         r = (uint32_t)ptimer_get_count(s->ptimer0);
 100         /* milkymist timer counts up */
 101         r = s->regs[R_TIMER0_COMPARE] - r;
 102         break;
 103     case R_TIMER1_COUNTER:
 104         r = (uint32_t)ptimer_get_count(s->ptimer1);
 105         /* milkymist timer counts up */
 106         r = s->regs[R_TIMER1_COMPARE] - r;
 107         break;
 108     case R_GPIO_IN:
 109     case R_GPIO_OUT:
 110     case R_GPIO_INTEN:
 111     case R_TIMER0_CONTROL:
 112     case R_TIMER0_COMPARE:
 113     case R_TIMER1_CONTROL:
 114     case R_TIMER1_COMPARE:
 115     case R_ICAP:
 116     case R_CAPABILITIES:
 117     case R_SYSTEM_ID:
 118         r = s->regs[addr];
 119         break;
 120
 121     default:
 122         error_report("milkymist_sysctl: read access to unknown register 0x"
 123                 TARGET_FMT_plx, addr << 2);
 124         break;
 125     }
 126
 127     trace_milkymist_sysctl_memory_read(addr << 2, r);
 128
 129     return r;
 130 }
 131
 132 static void sysctl_write(void *opaque, target_phys_addr_t addr, uint32_t value)
 133 {
 134     MilkymistSysctlState *s = opaque;
 135
 136     trace_milkymist_sysctl_memory_write(addr, value);
 137
 138     addr >>= 2;
 139     switch (addr) {
 140     case R_GPIO_OUT:
 141     case R_GPIO_INTEN:
 142     case R_TIMER0_COUNTER:
 143     case R_TIMER1_COUNTER:
 144         s->regs[addr] = value;
 145         break;
 146     case R_TIMER0_COMPARE:
 147         ptimer_set_limit(s->ptimer0, value, 0);
 148         s->regs[addr] = value;
 149         break;
 150     case R_TIMER1_COMPARE:
 151         ptimer_set_limit(s->ptimer1, value, 0);
 152         s->regs[addr] = value;
 153         break;
 154     case R_TIMER0_CONTROL:
 155         s->regs[addr] = value;
 156         if (s->regs[R_TIMER0_CONTROL] & CTRL_ENABLE) {
 157             trace_milkymist_sysctl_start_timer0();
 158             ptimer_set_count(s->ptimer0,
 159                     s->regs[R_TIMER0_COMPARE] - s->regs[R_TIMER0_COUNTER]);
 160             ptimer_run(s->ptimer0, 0);
 161         } else {
 162             trace_milkymist_sysctl_stop_timer0();
 163             ptimer_stop(s->ptimer0);
 164         }
 165         break;
 166     case R_TIMER1_CONTROL:
 167         s->regs[addr] = value;
 168         if (s->regs[R_TIMER1_CONTROL] & CTRL_ENABLE) {
 169             trace_milkymist_sysctl_start_timer1();
 170             ptimer_set_count(s->ptimer1,
 171                     s->regs[R_TIMER1_COMPARE] - s->regs[R_TIMER1_COUNTER]);
 172             ptimer_run(s->ptimer1, 0);
 173         } else {
 174             trace_milkymist_sysctl_stop_timer1();
 175             ptimer_stop(s->ptimer1);
 176         }
 177         break;
 178     case R_ICAP:
 179         sysctl_icap_write(s, value);
 180         break;
 181     case R_SYSTEM_ID:
 182         qemu_system_reset_request();
 183         break;
 184
 185     case R_GPIO_IN:
 186     case R_CAPABILITIES:
 187         error_report("milkymist_sysctl: write to read-only register 0x"
 188                 TARGET_FMT_plx, addr << 2);
 189         break;
 190
 191     default:
 192         error_report("milkymist_sysctl: write access to unknown register 0x"
 193                 TARGET_FMT_plx, addr << 2);
 194         break;
 195     }
 196 }
 197
 198 static CPUReadMemoryFunc * const sysctl_read_fn[] = {
 199     NULL,
 200     NULL,
 201     &sysctl_read,
 202 };
 203
 204 static CPUWriteMemoryFunc * const sysctl_write_fn[] = {
 205     NULL,
 206     NULL,
 207     &sysctl_write,
 208 };
 209
 210 static void timer0_hit(void *opaque)
 211 {
 212     MilkymistSysctlState *s = opaque;
 213
 214     if (!(s->regs[R_TIMER0_CONTROL] & CTRL_AUTORESTART)) {
 215         s->regs[R_TIMER0_CONTROL] &= ~CTRL_ENABLE;
 216         trace_milkymist_sysctl_stop_timer0();
 217         ptimer_stop(s->ptimer0);
 218     }
 219
 220     trace_milkymist_sysctl_pulse_irq_timer0();
 221     qemu_irq_pulse(s->timer0_irq);
 222 }
 223
 224 static void timer1_hit(void *opaque)
 225 {
 226     MilkymistSysctlState *s = opaque;
 227
 228     if (!(s->regs[R_TIMER1_CONTROL] & CTRL_AUTORESTART)) {
 229         s->regs[R_TIMER1_CONTROL] &= ~CTRL_ENABLE;
 230         trace_milkymist_sysctl_stop_timer1();
 231         ptimer_stop(s->ptimer1);
 232     }
 233
 234     trace_milkymist_sysctl_pulse_irq_timer1();
 235     qemu_irq_pulse(s->timer1_irq);
 236 }
 237
 238 static void milkymist_sysctl_reset(DeviceState *d)
 239 {
 240     MilkymistSysctlState *s =
 241             container_of(d, MilkymistSysctlState, busdev.qdev);
 242     int i;
 243
 244     for (i = 0; i < R_MAX; i++) {
 245         s->regs[i] = 0;
 246     }
 247
 248     ptimer_stop(s->ptimer0);
 249     ptimer_stop(s->ptimer1);
 250
 251     /* defaults */
 252     s->regs[R_ICAP] = ICAP_READY;
 253     s->regs[R_SYSTEM_ID] = s->systemid;
 254     s->regs[R_CAPABILITIES] = s->capabilities;
 255     s->regs[R_GPIO_IN] = s->strappings;
 256 }
 257
 258 static int milkymist_sysctl_init(SysBusDevice *dev)
 259 {
 260     MilkymistSysctlState *s = FROM_SYSBUS(typeof(*s), dev);
 261     int sysctl_regs;
 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     sysctl_regs = cpu_register_io_memory(sysctl_read_fn, sysctl_write_fn, s,
 275             DEVICE_NATIVE_ENDIAN);
 276     sysbus_init_mmio(dev, R_MAX * 4, sysctl_regs);
 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)