qemu/hw/misc/sbsa_ec.c
Graeme Gregory dccb92b5ca hw/misc/sbsa_ec : Add an embedded controller for sbsa-ref
A difference between sbsa platform and the virt platform is PSCI is
handled by ARM-TF in the sbsa platform. This means that the PSCI code
there needs to communicate some of the platform power changes down
to the qemu code for things like shutdown/reset control.

Space has been left to extend the EC if we find other use cases in
future where ARM-TF and qemu need to communicate.

Signed-off-by: Graeme Gregory <graeme@nuviainc.com>
Reviewed-by: Leif Lindholm <leif@nuviainc.com>
Tested-by: Leif Lindholm <leif@nuviainc.com>
Message-id: 20200826141952.136164-2-graeme@nuviainc.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2020-09-01 14:01:12 +01:00

99 lines
2.6 KiB
C

/*
* ARM SBSA Reference Platform Embedded Controller
*
* A device to allow PSCI running in the secure side of sbsa-ref machine
* to communicate platform power states to qemu.
*
* Copyright (c) 2020 Nuvia Inc
* Written by Graeme Gregory <graeme@nuviainc.com>
*
* SPDX-License-Identifer: GPL-2.0-or-later
*/
#include "qemu/osdep.h"
#include "qemu-common.h"
#include "qemu/log.h"
#include "hw/sysbus.h"
#include "sysemu/runstate.h"
typedef struct {
SysBusDevice parent_obj;
MemoryRegion iomem;
} SECUREECState;
#define TYPE_SBSA_EC "sbsa-ec"
#define SECURE_EC(obj) OBJECT_CHECK(SECUREECState, (obj), TYPE_SBSA_EC)
enum sbsa_ec_powerstates {
SBSA_EC_CMD_POWEROFF = 0x01,
SBSA_EC_CMD_REBOOT = 0x02,
};
static uint64_t sbsa_ec_read(void *opaque, hwaddr offset, unsigned size)
{
/* No use for this currently */
qemu_log_mask(LOG_GUEST_ERROR, "sbsa-ec: no readable registers");
return 0;
}
static void sbsa_ec_write(void *opaque, hwaddr offset,
uint64_t value, unsigned size)
{
if (offset == 0) { /* PSCI machine power command register */
switch (value) {
case SBSA_EC_CMD_POWEROFF:
qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
break;
case SBSA_EC_CMD_REBOOT:
qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
break;
default:
qemu_log_mask(LOG_GUEST_ERROR,
"sbsa-ec: unknown power command");
}
} else {
qemu_log_mask(LOG_GUEST_ERROR, "sbsa-ec: unknown EC register");
}
}
static const MemoryRegionOps sbsa_ec_ops = {
.read = sbsa_ec_read,
.write = sbsa_ec_write,
.endianness = DEVICE_NATIVE_ENDIAN,
.valid.min_access_size = 4,
.valid.max_access_size = 4,
};
static void sbsa_ec_init(Object *obj)
{
SECUREECState *s = SECURE_EC(obj);
SysBusDevice *dev = SYS_BUS_DEVICE(obj);
memory_region_init_io(&s->iomem, obj, &sbsa_ec_ops, s, "sbsa-ec",
0x1000);
sysbus_init_mmio(dev, &s->iomem);
}
static void sbsa_ec_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
/* No vmstate or reset required: device has no internal state */
dc->user_creatable = false;
}
static const TypeInfo sbsa_ec_info = {
.name = TYPE_SBSA_EC,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(SECUREECState),
.instance_init = sbsa_ec_init,
.class_init = sbsa_ec_class_init,
};
static void sbsa_ec_register_type(void)
{
type_register_static(&sbsa_ec_info);
}
type_init(sbsa_ec_register_type);