xref: /openbmc/qemu/hw/nvram/aspeed_otp.c (revision c79e29ef45b9b760a28d36a0beccfc95fe6d7fbe)
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     uint64_t perm;
39 
40     if (s->blk) {
41         perm = BLK_PERM_CONSISTENT_READ |
42                (blk_supports_write_perm(s->blk) ? BLK_PERM_WRITE : 0);
43         if (blk_set_perm(s->blk, perm, BLK_PERM_ALL, errp) < 0) {
44             return false;
45         }
46         if (blk_pread(s->blk, 0, s->size, s->storage, 0) < 0) {
47             error_setg(errp, "Failed to read the initial flash content");
48             return false;
49         }
50     } else {
51         num = s->size / sizeof(uint32_t);
52         p = (uint32_t *)s->storage;
53         for (i = 0; i < num; i++) {
54             p[i] = (i % 2 == 0) ? 0x00000000 : 0xFFFFFFFF;
55         }
56     }
57     return true;
58 }
59 
60 static const MemoryRegionOps aspeed_otp_ops = {
61     .read = aspeed_otp_read,
62     .write = aspeed_otp_write,
63     .endianness = DEVICE_LITTLE_ENDIAN,
64     .valid.min_access_size = 1,
65     .valid.max_access_size = 4,
66 };
67 
68 static void aspeed_otp_realize(DeviceState *dev, Error **errp)
69 {
70     AspeedOTPState *s = ASPEED_OTP(dev);
71 
72     if (s->size == 0) {
73         error_setg(errp, "aspeed.otp: 'size' property must be set");
74         return;
75     }
76 
77     s->storage = blk_blockalign(s->blk, s->size);
78 
79     if (!aspeed_otp_init_storage(s, errp)) {
80         return;
81     }
82 
83     memory_region_init_io(&s->mmio, OBJECT(dev), &aspeed_otp_ops,
84                           s, "aspeed.otp", s->size);
85     address_space_init(&s->as, &s->mmio, NULL);
86 }
87 
88 static const Property aspeed_otp_properties[] = {
89     DEFINE_PROP_UINT64("size", AspeedOTPState, size, 0),
90     DEFINE_PROP_DRIVE("drive", AspeedOTPState, blk),
91 };
92 
93 static void aspeed_otp_class_init(ObjectClass *klass, const void *data)
94 {
95     DeviceClass *dc = DEVICE_CLASS(klass);
96     dc->realize = aspeed_otp_realize;
97     device_class_set_props(dc, aspeed_otp_properties);
98 }
99 
100 static const TypeInfo aspeed_otp_info = {
101     .name          = TYPE_ASPEED_OTP,
102     .parent        = TYPE_DEVICE,
103     .instance_size = sizeof(AspeedOTPState),
104     .class_init    = aspeed_otp_class_init,
105 };
106 
107 static void aspeed_otp_register_types(void)
108 {
109     type_register_static(&aspeed_otp_info);
110 }
111 
112 type_init(aspeed_otp_register_types)
113