1 /*
2 * BCM2835 Power Management emulation
3 *
4 * Copyright (C) 2017 Marcin Chojnacki <marcinch7@gmail.com>
5 * Copyright (C) 2021 Nolan Leake <nolan@sigbus.net>
6 *
7 * This work is licensed under the terms of the GNU GPL, version 2 or later.
8 * See the COPYING file in the top-level directory.
9 */
10
11 #include "qemu/osdep.h"
12 #include "qemu/log.h"
13 #include "qemu/module.h"
14 #include "hw/misc/bcm2835_powermgt.h"
15 #include "migration/vmstate.h"
16 #include "sysemu/runstate.h"
17
18 #define PASSWORD 0x5a000000
19 #define PASSWORD_MASK 0xff000000
20
21 #define R_RSTC 0x1c
22 #define V_RSTC_RESET 0x20
23 #define R_RSTS 0x20
24 #define V_RSTS_POWEROFF 0x555 /* Linux uses partition 63 to indicate halt. */
25 #define R_WDOG 0x24
26
bcm2835_powermgt_read(void * opaque,hwaddr offset,unsigned size)27 static uint64_t bcm2835_powermgt_read(void *opaque, hwaddr offset,
28 unsigned size)
29 {
30 BCM2835PowerMgtState *s = (BCM2835PowerMgtState *)opaque;
31 uint32_t res = 0;
32
33 switch (offset) {
34 case R_RSTC:
35 res = s->rstc;
36 break;
37 case R_RSTS:
38 res = s->rsts;
39 break;
40 case R_WDOG:
41 res = s->wdog;
42 break;
43
44 default:
45 qemu_log_mask(LOG_UNIMP,
46 "bcm2835_powermgt_read: Unknown offset 0x%08"HWADDR_PRIx
47 "\n", offset);
48 res = 0;
49 break;
50 }
51
52 return res;
53 }
54
bcm2835_powermgt_write(void * opaque,hwaddr offset,uint64_t value,unsigned size)55 static void bcm2835_powermgt_write(void *opaque, hwaddr offset,
56 uint64_t value, unsigned size)
57 {
58 BCM2835PowerMgtState *s = (BCM2835PowerMgtState *)opaque;
59
60 if ((value & PASSWORD_MASK) != PASSWORD) {
61 qemu_log_mask(LOG_GUEST_ERROR,
62 "bcm2835_powermgt_write: Bad password 0x%"PRIx64
63 " at offset 0x%08"HWADDR_PRIx"\n",
64 value, offset);
65 return;
66 }
67
68 value = value & ~PASSWORD_MASK;
69
70 switch (offset) {
71 case R_RSTC:
72 s->rstc = value;
73 if (value & V_RSTC_RESET) {
74 if ((s->rsts & 0xfff) == V_RSTS_POWEROFF) {
75 qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
76 } else {
77 qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
78 }
79 }
80 break;
81 case R_RSTS:
82 qemu_log_mask(LOG_UNIMP,
83 "bcm2835_powermgt_write: RSTS\n");
84 s->rsts = value;
85 break;
86 case R_WDOG:
87 qemu_log_mask(LOG_UNIMP,
88 "bcm2835_powermgt_write: WDOG\n");
89 s->wdog = value;
90 break;
91
92 default:
93 qemu_log_mask(LOG_UNIMP,
94 "bcm2835_powermgt_write: Unknown offset 0x%08"HWADDR_PRIx
95 "\n", offset);
96 break;
97 }
98 }
99
100 static const MemoryRegionOps bcm2835_powermgt_ops = {
101 .read = bcm2835_powermgt_read,
102 .write = bcm2835_powermgt_write,
103 .endianness = DEVICE_NATIVE_ENDIAN,
104 .impl.min_access_size = 4,
105 .impl.max_access_size = 4,
106 };
107
108 static const VMStateDescription vmstate_bcm2835_powermgt = {
109 .name = TYPE_BCM2835_POWERMGT,
110 .version_id = 1,
111 .minimum_version_id = 1,
112 .fields = (const VMStateField[]) {
113 VMSTATE_UINT32(rstc, BCM2835PowerMgtState),
114 VMSTATE_UINT32(rsts, BCM2835PowerMgtState),
115 VMSTATE_UINT32(wdog, BCM2835PowerMgtState),
116 VMSTATE_END_OF_LIST()
117 }
118 };
119
bcm2835_powermgt_init(Object * obj)120 static void bcm2835_powermgt_init(Object *obj)
121 {
122 BCM2835PowerMgtState *s = BCM2835_POWERMGT(obj);
123
124 memory_region_init_io(&s->iomem, obj, &bcm2835_powermgt_ops, s,
125 TYPE_BCM2835_POWERMGT, 0x200);
126 sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
127 }
128
bcm2835_powermgt_reset(DeviceState * dev)129 static void bcm2835_powermgt_reset(DeviceState *dev)
130 {
131 BCM2835PowerMgtState *s = BCM2835_POWERMGT(dev);
132
133 /* https://elinux.org/BCM2835_registers#PM */
134 s->rstc = 0x00000102;
135 s->rsts = 0x00001000;
136 s->wdog = 0x00000000;
137 }
138
bcm2835_powermgt_class_init(ObjectClass * klass,void * data)139 static void bcm2835_powermgt_class_init(ObjectClass *klass, void *data)
140 {
141 DeviceClass *dc = DEVICE_CLASS(klass);
142
143 dc->reset = bcm2835_powermgt_reset;
144 dc->vmsd = &vmstate_bcm2835_powermgt;
145 }
146
147 static const TypeInfo bcm2835_powermgt_info = {
148 .name = TYPE_BCM2835_POWERMGT,
149 .parent = TYPE_SYS_BUS_DEVICE,
150 .instance_size = sizeof(BCM2835PowerMgtState),
151 .class_init = bcm2835_powermgt_class_init,
152 .instance_init = bcm2835_powermgt_init,
153 };
154
bcm2835_powermgt_register_types(void)155 static void bcm2835_powermgt_register_types(void)
156 {
157 type_register_static(&bcm2835_powermgt_info);
158 }
159
160 type_init(bcm2835_powermgt_register_types)
161