blob: f1eeda2786291640d5fa116d98a65db7ebbad773 [file] [log] [blame]
/*
* BCM2835 SOC MPHI emulation
*
* Very basic emulation, only providing the FIQ interrupt needed to
* allow the dwc-otg USB host controller driver in the Raspbian kernel
* to function.
*
* Copyright (c) 2020 Paul Zimmerman <pauldzim@gmail.com>
*
* 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 "qapi/error.h"
#include "hw/misc/bcm2835_mphi.h"
#include "migration/vmstate.h"
#include "qemu/error-report.h"
#include "qemu/log.h"
#include "qemu/main-loop.h"
static inline void mphi_raise_irq(BCM2835MphiState *s)
{
qemu_set_irq(s->irq, 1);
}
static inline void mphi_lower_irq(BCM2835MphiState *s)
{
qemu_set_irq(s->irq, 0);
}
static uint64_t mphi_reg_read(void *ptr, hwaddr addr, unsigned size)
{
BCM2835MphiState *s = ptr;
uint32_t val = 0;
switch (addr) {
case 0x28: /* outdda */
val = s->outdda;
break;
case 0x2c: /* outddb */
val = s->outddb;
break;
case 0x4c: /* ctrl */
val = s->ctrl;
val |= 1 << 17;
break;
case 0x50: /* intstat */
val = s->intstat;
break;
case 0x1f0: /* swirq_set */
val = s->swirq;
break;
case 0x1f4: /* swirq_clr */
val = s->swirq;
break;
default:
qemu_log_mask(LOG_UNIMP, "read from unknown register");
break;
}
return val;
}
static void mphi_reg_write(void *ptr, hwaddr addr, uint64_t val, unsigned size)
{
BCM2835MphiState *s = ptr;
int do_irq = 0;
switch (addr) {
case 0x28: /* outdda */
s->outdda = val;
break;
case 0x2c: /* outddb */
s->outddb = val;
if (val & (1 << 29)) {
do_irq = 1;
}
break;
case 0x4c: /* ctrl */
s->ctrl = val;
if (val & (1 << 16)) {
do_irq = -1;
}
break;
case 0x50: /* intstat */
s->intstat = val;
if (val & ((1 << 16) | (1 << 29))) {
do_irq = -1;
}
break;
case 0x1f0: /* swirq_set */
s->swirq |= val;
do_irq = 1;
break;
case 0x1f4: /* swirq_clr */
s->swirq &= ~val;
do_irq = -1;
break;
default:
qemu_log_mask(LOG_UNIMP, "write to unknown register");
return;
}
if (do_irq > 0) {
mphi_raise_irq(s);
} else if (do_irq < 0) {
mphi_lower_irq(s);
}
}
static const MemoryRegionOps mphi_mmio_ops = {
.read = mphi_reg_read,
.write = mphi_reg_write,
.impl.min_access_size = 4,
.impl.max_access_size = 4,
.endianness = DEVICE_LITTLE_ENDIAN,
};
static void mphi_reset(DeviceState *dev)
{
BCM2835MphiState *s = BCM2835_MPHI(dev);
s->outdda = 0;
s->outddb = 0;
s->ctrl = 0;
s->intstat = 0;
s->swirq = 0;
}
static void mphi_realize(DeviceState *dev, Error **errp)
{
SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
BCM2835MphiState *s = BCM2835_MPHI(dev);
sysbus_init_irq(sbd, &s->irq);
}
static void mphi_init(Object *obj)
{
SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
BCM2835MphiState *s = BCM2835_MPHI(obj);
memory_region_init_io(&s->iomem, obj, &mphi_mmio_ops, s, "mphi", MPHI_MMIO_SIZE);
sysbus_init_mmio(sbd, &s->iomem);
}
const VMStateDescription vmstate_mphi_state = {
.name = "mphi",
.version_id = 1,
.minimum_version_id = 1,
.fields = (const VMStateField[]) {
VMSTATE_UINT32(outdda, BCM2835MphiState),
VMSTATE_UINT32(outddb, BCM2835MphiState),
VMSTATE_UINT32(ctrl, BCM2835MphiState),
VMSTATE_UINT32(intstat, BCM2835MphiState),
VMSTATE_UINT32(swirq, BCM2835MphiState),
VMSTATE_END_OF_LIST()
}
};
static void mphi_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->realize = mphi_realize;
dc->reset = mphi_reset;
dc->vmsd = &vmstate_mphi_state;
}
static const TypeInfo bcm2835_mphi_type_info = {
.name = TYPE_BCM2835_MPHI,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(BCM2835MphiState),
.instance_init = mphi_init,
.class_init = mphi_class_init,
};
static void bcm2835_mphi_register_types(void)
{
type_register_static(&bcm2835_mphi_type_info);
}
type_init(bcm2835_mphi_register_types)