Merge tag 'pull-target-arm-20220922' of https://git.linaro.org/people/pmaydell/qemu...
[qemu.git] / hw / misc / imx7_snvs.c
1 /*
2 * IMX7 Secure Non-Volatile Storage
3 *
4 * Copyright (c) 2018, Impinj, Inc.
5 *
6 * Author: Andrey Smirnov <andrew.smirnov@gmail.com>
7 *
8 * This work is licensed under the terms of the GNU GPL, version 2 or later.
9 * See the COPYING file in the top-level directory.
10 *
11 * Bare minimum emulation code needed to support being able to shut
12 * down linux guest gracefully.
13 */
14
15 #include "qemu/osdep.h"
16 #include "hw/misc/imx7_snvs.h"
17 #include "qemu/module.h"
18 #include "sysemu/runstate.h"
19
20 static uint64_t imx7_snvs_read(void *opaque, hwaddr offset, unsigned size)
21 {
22 return 0;
23 }
24
25 static void imx7_snvs_write(void *opaque, hwaddr offset,
26 uint64_t v, unsigned size)
27 {
28 const uint32_t value = v;
29 const uint32_t mask = SNVS_LPCR_TOP | SNVS_LPCR_DP_EN;
30
31 if (offset == SNVS_LPCR && ((value & mask) == mask)) {
32 qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
33 }
34 }
35
36 static const struct MemoryRegionOps imx7_snvs_ops = {
37 .read = imx7_snvs_read,
38 .write = imx7_snvs_write,
39 .endianness = DEVICE_NATIVE_ENDIAN,
40 .impl = {
41 /*
42 * Our device would not work correctly if the guest was doing
43 * unaligned access. This might not be a limitation on the real
44 * device but in practice there is no reason for a guest to access
45 * this device unaligned.
46 */
47 .min_access_size = 4,
48 .max_access_size = 4,
49 .unaligned = false,
50 },
51 };
52
53 static void imx7_snvs_init(Object *obj)
54 {
55 SysBusDevice *sd = SYS_BUS_DEVICE(obj);
56 IMX7SNVSState *s = IMX7_SNVS(obj);
57
58 memory_region_init_io(&s->mmio, obj, &imx7_snvs_ops, s,
59 TYPE_IMX7_SNVS, 0x1000);
60
61 sysbus_init_mmio(sd, &s->mmio);
62 }
63
64 static void imx7_snvs_class_init(ObjectClass *klass, void *data)
65 {
66 DeviceClass *dc = DEVICE_CLASS(klass);
67
68 dc->desc = "i.MX7 Secure Non-Volatile Storage Module";
69 }
70
71 static const TypeInfo imx7_snvs_info = {
72 .name = TYPE_IMX7_SNVS,
73 .parent = TYPE_SYS_BUS_DEVICE,
74 .instance_size = sizeof(IMX7SNVSState),
75 .instance_init = imx7_snvs_init,
76 .class_init = imx7_snvs_class_init,
77 };
78
79 static void imx7_snvs_register_type(void)
80 {
81 type_register_static(&imx7_snvs_info);
82 }
83 type_init(imx7_snvs_register_type)