xref: /openbmc/qemu/hw/nvram/ds1225y.c (revision 7f709ce7)
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/sysbus.h"
27 #include "trace.h"
28 
29 typedef struct {
30     MemoryRegion iomem;
31     uint32_t chip_size;
32     char *filename;
33     FILE *file;
34     uint8_t *contents;
35 } NvRamState;
36 
37 static uint64_t nvram_read(void *opaque, hwaddr addr, unsigned size)
38 {
39     NvRamState *s = opaque;
40     uint32_t val;
41 
42     val = s->contents[addr];
43     trace_nvram_read(addr, val);
44     return val;
45 }
46 
47 static void nvram_write(void *opaque, hwaddr addr, uint64_t val,
48                         unsigned size)
49 {
50     NvRamState *s = opaque;
51 
52     val &= 0xff;
53     trace_nvram_write(addr, s->contents[addr], val);
54 
55     s->contents[addr] = val;
56     if (s->file) {
57         fseek(s->file, addr, SEEK_SET);
58         fputc(val, s->file);
59         fflush(s->file);
60     }
61 }
62 
63 static const MemoryRegionOps nvram_ops = {
64     .read = nvram_read,
65     .write = nvram_write,
66     .impl = {
67         .min_access_size = 1,
68         .max_access_size = 1,
69     },
70     .endianness = DEVICE_LITTLE_ENDIAN,
71 };
72 
73 static int nvram_post_load(void *opaque, int version_id)
74 {
75     NvRamState *s = opaque;
76 
77     /* Close file, as filename may has changed in load/store process */
78     if (s->file) {
79         fclose(s->file);
80     }
81 
82     /* Write back nvram contents */
83     s->file = fopen(s->filename, "wb");
84     if (s->file) {
85         /* Write back contents, as 'wb' mode cleaned the file */
86         if (fwrite(s->contents, s->chip_size, 1, s->file) != 1) {
87             printf("nvram_post_load: short write\n");
88         }
89         fflush(s->file);
90     }
91 
92     return 0;
93 }
94 
95 static const VMStateDescription vmstate_nvram = {
96     .name = "nvram",
97     .version_id = 0,
98     .minimum_version_id = 0,
99     .post_load = nvram_post_load,
100     .fields = (VMStateField[]) {
101         VMSTATE_VARRAY_UINT32(contents, NvRamState, chip_size, 0,
102                               vmstate_info_uint8, uint8_t),
103         VMSTATE_END_OF_LIST()
104     }
105 };
106 
107 #define TYPE_DS1225Y "ds1225y"
108 #define DS1225Y(obj) OBJECT_CHECK(SysBusNvRamState, (obj), TYPE_DS1225Y)
109 
110 typedef struct {
111     SysBusDevice parent_obj;
112 
113     NvRamState nvram;
114 } SysBusNvRamState;
115 
116 static int nvram_sysbus_initfn(SysBusDevice *dev)
117 {
118     SysBusNvRamState *sys = DS1225Y(dev);
119     NvRamState *s = &sys->nvram;
120     FILE *file;
121 
122     s->contents = g_malloc0(s->chip_size);
123 
124     memory_region_init_io(&s->iomem, OBJECT(s), &nvram_ops, s,
125                           "nvram", s->chip_size);
126     sysbus_init_mmio(dev, &s->iomem);
127 
128     /* Read current file */
129     file = fopen(s->filename, "rb");
130     if (file) {
131         /* Read nvram contents */
132         if (fread(s->contents, s->chip_size, 1, file) != 1) {
133             printf("nvram_sysbus_initfn: short read\n");
134         }
135         fclose(file);
136     }
137     nvram_post_load(s, 0);
138 
139     return 0;
140 }
141 
142 static Property nvram_sysbus_properties[] = {
143     DEFINE_PROP_UINT32("size", SysBusNvRamState, nvram.chip_size, 0x2000),
144     DEFINE_PROP_STRING("filename", SysBusNvRamState, nvram.filename),
145     DEFINE_PROP_END_OF_LIST(),
146 };
147 
148 static void nvram_sysbus_class_init(ObjectClass *klass, void *data)
149 {
150     DeviceClass *dc = DEVICE_CLASS(klass);
151     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
152 
153     k->init = nvram_sysbus_initfn;
154     dc->vmsd = &vmstate_nvram;
155     dc->props = nvram_sysbus_properties;
156 }
157 
158 static const TypeInfo nvram_sysbus_info = {
159     .name          = TYPE_DS1225Y,
160     .parent        = TYPE_SYS_BUS_DEVICE,
161     .instance_size = sizeof(SysBusNvRamState),
162     .class_init    = nvram_sysbus_class_init,
163 };
164 
165 static void nvram_register_types(void)
166 {
167     type_register_static(&nvram_sysbus_info);
168 }
169 
170 type_init(nvram_register_types)
171