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/sysbus.h"
26#include "migration/vmstate.h"
27#include "trace.h"
28#include "qemu/error-report.h"
29#include "qemu/module.h"
30
31enum {
32 R_SYSTEM = 0,
33 R_BYPASS,
34 R_TIMING,
35 R_IODELAY,
36 R_MAX
37};
38
39enum {
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
49struct MilkymistHpdmcState {
50 SysBusDevice parent_obj;
51
52 MemoryRegion regs_region;
53
54 uint32_t regs[R_MAX];
55};
56typedef struct MilkymistHpdmcState MilkymistHpdmcState;
57
58static 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
84static 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
109static 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
119static 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
133static 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
142static 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
152static 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
161static 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
168static void milkymist_hpdmc_register_types(void)
169{
170 type_register_static(&milkymist_hpdmc_info);
171}
172
173type_init(milkymist_hpdmc_register_types)
174