1 /*
2 * ARM SBSA Reference Platform Embedded Controller
3 *
4 * A device to allow PSCI running in the secure side of sbsa-ref machine
5 * to communicate platform power states to qemu.
6 *
7 * Copyright (c) 2020 Nuvia Inc
8 * Written by Graeme Gregory <graeme@nuviainc.com>
9 *
10 * SPDX-License-Identifier: GPL-2.0-or-later
11 */
12
13 #include "qemu/osdep.h"
14 #include "qemu/log.h"
15 #include "hw/sysbus.h"
16 #include "sysemu/runstate.h"
17
18 typedef struct SECUREECState {
19 SysBusDevice parent_obj;
20 MemoryRegion iomem;
21 } SECUREECState;
22
23 #define TYPE_SBSA_SECURE_EC "sbsa-ec"
24 OBJECT_DECLARE_SIMPLE_TYPE(SECUREECState, SBSA_SECURE_EC)
25
26 enum sbsa_ec_powerstates {
27 SBSA_EC_CMD_POWEROFF = 0x01,
28 SBSA_EC_CMD_REBOOT = 0x02,
29 };
30
sbsa_ec_read(void * opaque,hwaddr offset,unsigned size)31 static uint64_t sbsa_ec_read(void *opaque, hwaddr offset, unsigned size)
32 {
33 /* No use for this currently */
34 qemu_log_mask(LOG_GUEST_ERROR, "sbsa-ec: no readable registers");
35 return 0;
36 }
37
sbsa_ec_write(void * opaque,hwaddr offset,uint64_t value,unsigned size)38 static void sbsa_ec_write(void *opaque, hwaddr offset,
39 uint64_t value, unsigned size)
40 {
41 if (offset == 0) { /* PSCI machine power command register */
42 switch (value) {
43 case SBSA_EC_CMD_POWEROFF:
44 qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
45 break;
46 case SBSA_EC_CMD_REBOOT:
47 qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
48 break;
49 default:
50 qemu_log_mask(LOG_GUEST_ERROR,
51 "sbsa-ec: unknown power command");
52 }
53 } else {
54 qemu_log_mask(LOG_GUEST_ERROR, "sbsa-ec: unknown EC register");
55 }
56 }
57
58 static const MemoryRegionOps sbsa_ec_ops = {
59 .read = sbsa_ec_read,
60 .write = sbsa_ec_write,
61 .endianness = DEVICE_NATIVE_ENDIAN,
62 .valid.min_access_size = 4,
63 .valid.max_access_size = 4,
64 };
65
sbsa_ec_init(Object * obj)66 static void sbsa_ec_init(Object *obj)
67 {
68 SECUREECState *s = SBSA_SECURE_EC(obj);
69 SysBusDevice *dev = SYS_BUS_DEVICE(obj);
70
71 memory_region_init_io(&s->iomem, obj, &sbsa_ec_ops, s, "sbsa-ec",
72 0x1000);
73 sysbus_init_mmio(dev, &s->iomem);
74 }
75
sbsa_ec_class_init(ObjectClass * klass,void * data)76 static void sbsa_ec_class_init(ObjectClass *klass, void *data)
77 {
78 DeviceClass *dc = DEVICE_CLASS(klass);
79
80 /* No vmstate or reset required: device has no internal state */
81 dc->user_creatable = false;
82 }
83
84 static const TypeInfo sbsa_ec_info = {
85 .name = TYPE_SBSA_SECURE_EC,
86 .parent = TYPE_SYS_BUS_DEVICE,
87 .instance_size = sizeof(SECUREECState),
88 .instance_init = sbsa_ec_init,
89 .class_init = sbsa_ec_class_init,
90 };
91
sbsa_ec_register_type(void)92 static void sbsa_ec_register_type(void)
93 {
94 type_register_static(&sbsa_ec_info);
95 }
96
97 type_init(sbsa_ec_register_type);
98