qemu/hw/misc/mps2-fpgaio.c

177 lines
4.6 KiB
C

/*
* ARM MPS2 AN505 FPGAIO emulation
*
* Copyright (c) 2018 Linaro Limited
* Written by Peter Maydell
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 or
* (at your option) any later version.
*/
/* This is a model of the "FPGA system control and I/O" block found
* in the AN505 FPGA image for the MPS2 devboard.
* It is documented in AN505:
* http://infocenter.arm.com/help/topic/com.arm.doc.dai0505b/index.html
*/
#include "qemu/osdep.h"
#include "qemu/log.h"
#include "qapi/error.h"
#include "trace.h"
#include "hw/sysbus.h"
#include "hw/registerfields.h"
#include "hw/misc/mps2-fpgaio.h"
REG32(LED0, 0)
REG32(BUTTON, 8)
REG32(CLK1HZ, 0x10)
REG32(CLK100HZ, 0x14)
REG32(COUNTER, 0x18)
REG32(PRESCALE, 0x1c)
REG32(PSCNTR, 0x20)
REG32(MISC, 0x4c)
static uint64_t mps2_fpgaio_read(void *opaque, hwaddr offset, unsigned size)
{
MPS2FPGAIO *s = MPS2_FPGAIO(opaque);
uint64_t r;
switch (offset) {
case A_LED0:
r = s->led0;
break;
case A_BUTTON:
/* User-pressable board buttons. We don't model that, so just return
* zeroes.
*/
r = 0;
break;
case A_PRESCALE:
r = s->prescale;
break;
case A_MISC:
r = s->misc;
break;
case A_CLK1HZ:
case A_CLK100HZ:
case A_COUNTER:
case A_PSCNTR:
/* These are all upcounters of various frequencies. */
qemu_log_mask(LOG_UNIMP, "MPS2 FPGAIO: counters unimplemented\n");
r = 0;
break;
default:
qemu_log_mask(LOG_GUEST_ERROR,
"MPS2 FPGAIO read: bad offset %x\n", (int) offset);
r = 0;
break;
}
trace_mps2_fpgaio_read(offset, r, size);
return r;
}
static void mps2_fpgaio_write(void *opaque, hwaddr offset, uint64_t value,
unsigned size)
{
MPS2FPGAIO *s = MPS2_FPGAIO(opaque);
trace_mps2_fpgaio_write(offset, value, size);
switch (offset) {
case A_LED0:
/* LED bits [1:0] control board LEDs. We don't currently have
* a mechanism for displaying this graphically, so use a trace event.
*/
trace_mps2_fpgaio_leds(value & 0x02 ? '*' : '.',
value & 0x01 ? '*' : '.');
s->led0 = value & 0x3;
break;
case A_PRESCALE:
s->prescale = value;
break;
case A_MISC:
/* These are control bits for some of the other devices on the
* board (SPI, CLCD, etc). We don't implement that yet, so just
* make the bits read as written.
*/
qemu_log_mask(LOG_UNIMP,
"MPS2 FPGAIO: MISC control bits unimplemented\n");
s->misc = value;
break;
default:
qemu_log_mask(LOG_GUEST_ERROR,
"MPS2 FPGAIO write: bad offset 0x%x\n", (int) offset);
break;
}
}
static const MemoryRegionOps mps2_fpgaio_ops = {
.read = mps2_fpgaio_read,
.write = mps2_fpgaio_write,
.endianness = DEVICE_LITTLE_ENDIAN,
};
static void mps2_fpgaio_reset(DeviceState *dev)
{
MPS2FPGAIO *s = MPS2_FPGAIO(dev);
trace_mps2_fpgaio_reset();
s->led0 = 0;
s->prescale = 0;
s->misc = 0;
}
static void mps2_fpgaio_init(Object *obj)
{
SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
MPS2FPGAIO *s = MPS2_FPGAIO(obj);
memory_region_init_io(&s->iomem, obj, &mps2_fpgaio_ops, s,
"mps2-fpgaio", 0x1000);
sysbus_init_mmio(sbd, &s->iomem);
}
static const VMStateDescription mps2_fpgaio_vmstate = {
.name = "mps2-fpgaio",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_UINT32(led0, MPS2FPGAIO),
VMSTATE_UINT32(prescale, MPS2FPGAIO),
VMSTATE_UINT32(misc, MPS2FPGAIO),
VMSTATE_END_OF_LIST()
}
};
static Property mps2_fpgaio_properties[] = {
/* Frequency of the prescale counter */
DEFINE_PROP_UINT32("prescale-clk", MPS2FPGAIO, prescale_clk, 20000000),
DEFINE_PROP_END_OF_LIST(),
};
static void mps2_fpgaio_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->vmsd = &mps2_fpgaio_vmstate;
dc->reset = mps2_fpgaio_reset;
dc->props = mps2_fpgaio_properties;
}
static const TypeInfo mps2_fpgaio_info = {
.name = TYPE_MPS2_FPGAIO,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(MPS2FPGAIO),
.instance_init = mps2_fpgaio_init,
.class_init = mps2_fpgaio_class_init,
};
static void mps2_fpgaio_register_types(void)
{
type_register_static(&mps2_fpgaio_info);
}
type_init(mps2_fpgaio_register_types);