1/*
2 * QEMU NVRAM emulation for DS1225Y chip
3 *
4 * Copyright (c) 2007-2008 Hervé Poussineau
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24
25#include "qemu/osdep.h"
26#include "hw/qdev-properties.h"
27#include "hw/sysbus.h"
28#include "migration/vmstate.h"
29#include "trace.h"
30#include "qemu/error-report.h"
31#include "qemu/module.h"
32
33typedef struct {
34 MemoryRegion iomem;
35 uint32_t chip_size;
36 char *filename;
37 FILE *file;
38 uint8_t *contents;
39} NvRamState;
40
41static uint64_t nvram_read(void *opaque, hwaddr addr, unsigned size)
42{
43 NvRamState *s = opaque;
44 uint32_t val;
45
46 val = s->contents[addr];
47 trace_nvram_read(addr, val);
48 return val;
49}
50
51static void nvram_write(void *opaque, hwaddr addr, uint64_t val,
52 unsigned size)
53{
54 NvRamState *s = opaque;
55
56 val &= 0xff;
57 trace_nvram_write(addr, s->contents[addr], val);
58
59 s->contents[addr] = val;
60 if (s->file) {
61 fseek(s->file, addr, SEEK_SET);
62 fputc(val, s->file);
63 fflush(s->file);
64 }
65}
66
67static const MemoryRegionOps nvram_ops = {
68 .read = nvram_read,
69 .write = nvram_write,
70 .impl = {
71 .min_access_size = 1,
72 .max_access_size = 1,
73 },
74 .endianness = DEVICE_LITTLE_ENDIAN,
75};
76
77static int nvram_post_load(void *opaque, int version_id)
78{
79 NvRamState *s = opaque;
80
81 /* Close file, as filename may has changed in load/store process */
82 if (s->file) {
83 fclose(s->file);
84 }
85
86 /* Write back nvram contents */
87 s->file = s->filename ? fopen(s->filename, "wb") : NULL;
88 if (s->file) {
89 /* Write back contents, as 'wb' mode cleaned the file */
90 if (fwrite(s->contents, s->chip_size, 1, s->file) != 1) {
91 printf("nvram_post_load: short write\n");
92 }
93 fflush(s->file);
94 }
95
96 return 0;
97}
98
99static const VMStateDescription vmstate_nvram = {
100 .name = "nvram",
101 .version_id = 0,
102 .minimum_version_id = 0,
103 .post_load = nvram_post_load,
104 .fields = (VMStateField[]) {
105 VMSTATE_VARRAY_UINT32(contents, NvRamState, chip_size, 0,
106 vmstate_info_uint8, uint8_t),
107 VMSTATE_END_OF_LIST()
108 }
109};
110
111#define TYPE_DS1225Y "ds1225y"
112#define DS1225Y(obj) OBJECT_CHECK(SysBusNvRamState, (obj), TYPE_DS1225Y)
113
114typedef struct {
115 SysBusDevice parent_obj;
116
117 NvRamState nvram;
118} SysBusNvRamState;
119
120static void nvram_sysbus_realize(DeviceState *dev, Error **errp)
121{
122 SysBusNvRamState *sys = DS1225Y(dev);
123 NvRamState *s = &sys->nvram;
124 FILE *file;
125
126 s->contents = g_malloc0(s->chip_size);
127
128 memory_region_init_io(&s->iomem, OBJECT(s), &nvram_ops, s,
129 "nvram", s->chip_size);
130 sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
131
132 /* Read current file */
133 file = s->filename ? fopen(s->filename, "rb") : NULL;
134 if (file) {
135 /* Read nvram contents */
136 if (fread(s->contents, s->chip_size, 1, file) != 1) {
137 error_report("nvram_sysbus_realize: short read");
138 }
139 fclose(file);
140 }
141 nvram_post_load(s, 0);
142}
143
144static Property nvram_sysbus_properties[] = {
145 DEFINE_PROP_UINT32("size", SysBusNvRamState, nvram.chip_size, 0x2000),
146 DEFINE_PROP_STRING("filename", SysBusNvRamState, nvram.filename),
147 DEFINE_PROP_END_OF_LIST(),
148};
149
150static void nvram_sysbus_class_init(ObjectClass *klass, void *data)
151{
152 DeviceClass *dc = DEVICE_CLASS(klass);
153
154 dc->realize = nvram_sysbus_realize;
155 dc->vmsd = &vmstate_nvram;
156 dc->props = nvram_sysbus_properties;
157}
158
159static const TypeInfo nvram_sysbus_info = {
160 .name = TYPE_DS1225Y,
161 .parent = TYPE_SYS_BUS_DEVICE,
162 .instance_size = sizeof(SysBusNvRamState),
163 .class_init = nvram_sysbus_class_init,
164};
165
166static void nvram_register_types(void)
167{
168 type_register_static(&nvram_sysbus_info);
169}
170
171type_init(nvram_register_types)
172