xref: /openbmc/qemu/hw/nvram/aspeed_otp.c (revision 12ef88d8cdcd26ee5db3bfb5516c2dddc601aadb)
1 /*
2  *  ASPEED OTP (One-Time Programmable) memory
3  *
4  *  Copyright (C) 2025 Aspeed
5  *
6  *  SPDX-License-Identifier: GPL-2.0-or-later
7  */
8 
9 #include "qemu/osdep.h"
10 #include "qemu/log.h"
11 #include "qapi/error.h"
12 #include "system/block-backend.h"
13 #include "hw/qdev-properties.h"
14 #include "hw/nvram/aspeed_otp.h"
15 
16 static uint64_t aspeed_otp_read(void *opaque, hwaddr offset, unsigned size)
17 {
18     AspeedOTPState *s = opaque;
19     uint64_t val = 0;
20 
21     memcpy(&val, s->storage + offset, size);
22 
23     return val;
24 }
25 
26 static void aspeed_otp_write(void *opaque, hwaddr otp_addr,
27                                 uint64_t val, unsigned size)
28 {
29     AspeedOTPState *s = opaque;
30 
31     memcpy(s->storage + otp_addr, &val, size);
32 }
33 
34 static bool aspeed_otp_init_storage(AspeedOTPState *s, Error **errp)
35 {
36     uint32_t *p;
37     int i, num;
38 
39         num = s->size / sizeof(uint32_t);
40         p = (uint32_t *)s->storage;
41         for (i = 0; i < num; i++) {
42             p[i] = (i % 2 == 0) ? 0x00000000 : 0xFFFFFFFF;
43         }
44 
45     return true;
46 }
47 
48 static const MemoryRegionOps aspeed_otp_ops = {
49     .read = aspeed_otp_read,
50     .write = aspeed_otp_write,
51     .endianness = DEVICE_LITTLE_ENDIAN,
52     .valid.min_access_size = 1,
53     .valid.max_access_size = 4,
54 };
55 
56 static void aspeed_otp_realize(DeviceState *dev, Error **errp)
57 {
58     AspeedOTPState *s = ASPEED_OTP(dev);
59 
60     if (s->size == 0) {
61         error_setg(errp, "aspeed.otp: 'size' property must be set");
62         return;
63     }
64 
65     s->storage = blk_blockalign(s->blk, s->size);
66 
67     if (!aspeed_otp_init_storage(s, errp)) {
68         return;
69     }
70 
71     memory_region_init_io(&s->mmio, OBJECT(dev), &aspeed_otp_ops,
72                           s, "aspeed.otp", s->size);
73     address_space_init(&s->as, &s->mmio, NULL);
74 }
75 
76 static const Property aspeed_otp_properties[] = {
77     DEFINE_PROP_UINT64("size", AspeedOTPState, size, 0),
78 };
79 
80 static void aspeed_otp_class_init(ObjectClass *klass, const void *data)
81 {
82     DeviceClass *dc = DEVICE_CLASS(klass);
83     dc->realize = aspeed_otp_realize;
84     device_class_set_props(dc, aspeed_otp_properties);
85 }
86 
87 static const TypeInfo aspeed_otp_info = {
88     .name          = TYPE_ASPEED_OTP,
89     .parent        = TYPE_DEVICE,
90     .instance_size = sizeof(AspeedOTPState),
91     .class_init    = aspeed_otp_class_init,
92 };
93 
94 static void aspeed_otp_register_types(void)
95 {
96     type_register_static(&aspeed_otp_info);
97 }
98 
99 type_init(aspeed_otp_register_types)
100