LXR qemu/hw/misc/milkymist-hpdmc.c

   1/*
   2 *  QEMU model of the Milkymist High Performance Dynamic Memory 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://milkymist.walle.cc/socdoc/hpdmc.pdf
  22 */
  23
  24#include "qemu/osdep.h"
  25#include "hw/hw.h"
  26#include "hw/sysbus.h"
  27#include "trace.h"
  28#include "qemu/error-report.h"
  29
  30enum {
  31    R_SYSTEM = 0,
  32    R_BYPASS,
  33    R_TIMING,
  34    R_IODELAY,
  35    R_MAX
  36};
  37
  38enum {
  39    IODELAY_DQSDELAY_RDY = (1<<5),
  40    IODELAY_PLL1_LOCKED  = (1<<6),
  41    IODELAY_PLL2_LOCKED  = (1<<7),
  42};
  43
  44#define TYPE_MILKYMIST_HPDMC "milkymist-hpdmc"
  45#define MILKYMIST_HPDMC(obj) \
  46    OBJECT_CHECK(MilkymistHpdmcState, (obj), TYPE_MILKYMIST_HPDMC)
  47
  48struct MilkymistHpdmcState {
  49    SysBusDevice parent_obj;
  50
  51    MemoryRegion regs_region;
  52
  53    uint32_t regs[R_MAX];
  54};
  55typedef struct MilkymistHpdmcState MilkymistHpdmcState;
  56
  57static uint64_t hpdmc_read(void *opaque, hwaddr addr,
  58                           unsigned size)
  59{
  60    MilkymistHpdmcState *s = opaque;
  61    uint32_t r = 0;
  62
  63    addr >>= 2;
  64    switch (addr) {
  65    case R_SYSTEM:
  66    case R_BYPASS:
  67    case R_TIMING:
  68    case R_IODELAY:
  69        r = s->regs[addr];
  70        break;
  71
  72    default:
  73        error_report("milkymist_hpdmc: read access to unknown register 0x"
  74                TARGET_FMT_plx, addr << 2);
  75        break;
  76    }
  77
  78    trace_milkymist_hpdmc_memory_read(addr << 2, r);
  79
  80    return r;
  81}
  82
  83static void hpdmc_write(void *opaque, hwaddr addr, uint64_t value,
  84                        unsigned size)
  85{
  86    MilkymistHpdmcState *s = opaque;
  87
  88    trace_milkymist_hpdmc_memory_write(addr, value);
  89
  90    addr >>= 2;
  91    switch (addr) {
  92    case R_SYSTEM:
  93    case R_BYPASS:
  94    case R_TIMING:
  95        s->regs[addr] = value;
  96        break;
  97    case R_IODELAY:
  98        /* ignore writes */
  99        break;
 100
 101    default:
 102        error_report("milkymist_hpdmc: write access to unknown register 0x"
 103                TARGET_FMT_plx, addr << 2);
 104        break;
 105    }
 106}
 107
 108static const MemoryRegionOps hpdmc_mmio_ops = {
 109    .read = hpdmc_read,
 110    .write = hpdmc_write,
 111    .valid = {
 112        .min_access_size = 4,
 113        .max_access_size = 4,
 114    },
 115    .endianness = DEVICE_NATIVE_ENDIAN,
 116};
 117
 118static void milkymist_hpdmc_reset(DeviceState *d)
 119{
 120    MilkymistHpdmcState *s = MILKYMIST_HPDMC(d);
 121    int i;
 122
 123    for (i = 0; i < R_MAX; i++) {
 124        s->regs[i] = 0;
 125    }
 126
 127    /* defaults */
 128    s->regs[R_IODELAY] = IODELAY_DQSDELAY_RDY | IODELAY_PLL1_LOCKED
 129                         | IODELAY_PLL2_LOCKED;
 130}
 131
 132static void milkymist_hpdmc_realize(DeviceState *dev, Error **errp)
 133{
 134    MilkymistHpdmcState *s = MILKYMIST_HPDMC(dev);
 135
 136    memory_region_init_io(&s->regs_region, OBJECT(dev), &hpdmc_mmio_ops, s,
 137            "milkymist-hpdmc", R_MAX * 4);
 138    sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->regs_region);
 139}
 140
 141static const VMStateDescription vmstate_milkymist_hpdmc = {
 142    .name = "milkymist-hpdmc",
 143    .version_id = 1,
 144    .minimum_version_id = 1,
 145    .fields = (VMStateField[]) {
 146        VMSTATE_UINT32_ARRAY(regs, MilkymistHpdmcState, R_MAX),
 147        VMSTATE_END_OF_LIST()
 148    }
 149};
 150
 151static void milkymist_hpdmc_class_init(ObjectClass *klass, void *data)
 152{
 153    DeviceClass *dc = DEVICE_CLASS(klass);
 154
 155    dc->realize = milkymist_hpdmc_realize;
 156    dc->reset = milkymist_hpdmc_reset;
 157    dc->vmsd = &vmstate_milkymist_hpdmc;
 158}
 159
 160static const TypeInfo milkymist_hpdmc_info = {
 161    .name          = TYPE_MILKYMIST_HPDMC,
 162    .parent        = TYPE_SYS_BUS_DEVICE,
 163    .instance_size = sizeof(MilkymistHpdmcState),
 164    .class_init    = milkymist_hpdmc_class_init,
 165};
 166
 167static void milkymist_hpdmc_register_types(void)
 168{
 169    type_register_static(&milkymist_hpdmc_info);
 170}
 171
 172type_init(milkymist_hpdmc_register_types)
 173