qemu/hw/riscv/sifive_prci.c

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/*
* QEMU SiFive PRCI (Power, Reset, Clock, Interrupt)
*
* Copyright (c) 2017 SiFive, Inc.
*
* Simple model of the PRCI to emulate register reads made by the SDK BSP
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2 or later, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "hw/sysbus.h"
#include "target/riscv/cpu.h"
#include "hw/riscv/sifive_prci.h"
/* currently implements enough to mock freedom-e-sdk BSP clock programming */
static uint64_t sifive_prci_read(void *opaque, hwaddr addr, unsigned int size)
{
if (addr == 0 /* PRCI_HFROSCCFG */) {
return 1 << 31; /* ROSC_RDY */
}
if (addr == 8 /* PRCI_PLLCFG */) {
return 1 << 31; /* PLL_LOCK */
}
hw_error("%s: read: addr=0x%x\n", __func__, (int)addr);
return 0;
}
static void sifive_prci_write(void *opaque, hwaddr addr,
uint64_t val64, unsigned int size)
{
/* discard writes */
}
static const MemoryRegionOps sifive_prci_ops = {
.read = sifive_prci_read,
.write = sifive_prci_write,
.endianness = DEVICE_NATIVE_ENDIAN,
.valid = {
.min_access_size = 4,
.max_access_size = 4
}
};
static void sifive_prci_init(Object *obj)
{
SiFivePRCIState *s = SIFIVE_PRCI(obj);
memory_region_init_io(&s->mmio, obj, &sifive_prci_ops, s,
TYPE_SIFIVE_PRCI, 0x8000);
sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
}
static const TypeInfo sifive_prci_info = {
.name = TYPE_SIFIVE_PRCI,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(SiFivePRCIState),
.instance_init = sifive_prci_init,
};
static void sifive_prci_register_types(void)
{
type_register_static(&sifive_prci_info);
}
type_init(sifive_prci_register_types)
/*
* Create PRCI device.
*/
DeviceState *sifive_prci_create(hwaddr addr)
{
DeviceState *dev = qdev_create(NULL, TYPE_SIFIVE_PRCI);
qdev_init_nofail(dev);
sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, addr);
return dev;
}