qemu/hw/mem/npcm7xx_mc.c

85 lines
2.3 KiB
C

/*
* Nuvoton NPCM7xx Memory Controller stub
*
* Copyright 2020 Google LLC
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that 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.
*/
#include "qemu/osdep.h"
#include "hw/mem/npcm7xx_mc.h"
#include "qapi/error.h"
#include "qemu/log.h"
#include "qemu/module.h"
#include "qemu/units.h"
#define NPCM7XX_MC_REGS_SIZE (4 * KiB)
static uint64_t npcm7xx_mc_read(void *opaque, hwaddr addr, unsigned int size)
{
/*
* If bits 8..11 @ offset 0 are not zero, the boot block thinks the memory
* controller has already been initialized and will skip DDR training.
*/
if (addr == 0) {
return 0x100;
}
qemu_log_mask(LOG_UNIMP, "%s: mostly unimplemented\n", __func__);
return 0;
}
static void npcm7xx_mc_write(void *opaque, hwaddr addr, uint64_t v,
unsigned int size)
{
qemu_log_mask(LOG_UNIMP, "%s: mostly unimplemented\n", __func__);
}
static const MemoryRegionOps npcm7xx_mc_ops = {
.read = npcm7xx_mc_read,
.write = npcm7xx_mc_write,
.endianness = DEVICE_LITTLE_ENDIAN,
.valid = {
.min_access_size = 4,
.max_access_size = 4,
.unaligned = false,
},
};
static void npcm7xx_mc_realize(DeviceState *dev, Error **errp)
{
NPCM7xxMCState *s = NPCM7XX_MC(dev);
memory_region_init_io(&s->mmio, OBJECT(s), &npcm7xx_mc_ops, s, "regs",
NPCM7XX_MC_REGS_SIZE);
sysbus_init_mmio(&s->parent, &s->mmio);
}
static void npcm7xx_mc_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->desc = "NPCM7xx Memory Controller stub";
dc->realize = npcm7xx_mc_realize;
}
static const TypeInfo npcm7xx_mc_types[] = {
{
.name = TYPE_NPCM7XX_MC,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(NPCM7xxMCState),
.class_init = npcm7xx_mc_class_init,
},
};
DEFINE_TYPES(npcm7xx_mc_types);