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