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/log.h"
18#include "qemu/module.h"
19#include "sysemu/runstate.h"
20
21static uint64_t imx7_snvs_read(void *opaque, hwaddr offset, unsigned size)
22{
23 return 0;
24}
25
26static void imx7_snvs_write(void *opaque, hwaddr offset,
27 uint64_t v, unsigned size)
28{
29 const uint32_t value = v;
30 const uint32_t mask = SNVS_LPCR_TOP | SNVS_LPCR_DP_EN;
31
32 if (offset == SNVS_LPCR && ((value & mask) == mask)) {
33 qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
34 }
35}
36
37static const struct MemoryRegionOps imx7_snvs_ops = {
38 .read = imx7_snvs_read,
39 .write = imx7_snvs_write,
40 .endianness = DEVICE_NATIVE_ENDIAN,
41 .impl = {
42 /*
43 * Our device would not work correctly if the guest was doing
44 * unaligned access. This might not be a limitation on the real
45 * device but in practice there is no reason for a guest to access
46 * this device unaligned.
47 */
48 .min_access_size = 4,
49 .max_access_size = 4,
50 .unaligned = false,
51 },
52};
53
54static void imx7_snvs_init(Object *obj)
55{
56 SysBusDevice *sd = SYS_BUS_DEVICE(obj);
57 IMX7SNVSState *s = IMX7_SNVS(obj);
58
59 memory_region_init_io(&s->mmio, obj, &imx7_snvs_ops, s,
60 TYPE_IMX7_SNVS, 0x1000);
61
62 sysbus_init_mmio(sd, &s->mmio);
63}
64
65static void imx7_snvs_class_init(ObjectClass *klass, void *data)
66{
67 DeviceClass *dc = DEVICE_CLASS(klass);
68
69 dc->desc = "i.MX7 Secure Non-Volatile Storage Module";
70}
71
72static const TypeInfo imx7_snvs_info = {
73 .name = TYPE_IMX7_SNVS,
74 .parent = TYPE_SYS_BUS_DEVICE,
75 .instance_size = sizeof(IMX7SNVSState),
76 .instance_init = imx7_snvs_init,
77 .class_init = imx7_snvs_class_init,
78};
79
80static void imx7_snvs_register_type(void)
81{
82 type_register_static(&imx7_snvs_info);
83}
84type_init(imx7_snvs_register_type)
85