qemu/hw/milkymist-hpdmc.c
Michael Walle e4dc6d2cdc lm32: add Milkymist HPDMC support
This patch adds support for the Milkymist's High Performance Dynamic Memory
Controller. This is just a dumb model without any functionality. While the
real hardware acts for example as a bridge between software and hardware
for sending SDRAM commans, this model will only eat up these commands and
always returns the expected hardware states, eg. PLL locked etc.

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
2011-04-04 10:26:53 +02:00

161 lines
3.8 KiB
C

/*
* QEMU model of the Milkymist High Performance Dynamic Memory Controller.
*
* Copyright (c) 2010 Michael Walle <michael@walle.cc>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
*
* Specification available at:
* http://www.milkymist.org/socdoc/hpdmc.pdf
*/
#include "hw.h"
#include "sysbus.h"
#include "trace.h"
#include "qemu-error.h"
enum {
R_SYSTEM = 0,
R_BYPASS,
R_TIMING,
R_IODELAY,
R_MAX
};
enum {
IODELAY_DQSDELAY_RDY = (1<<5),
IODELAY_PLL1_LOCKED = (1<<6),
IODELAY_PLL2_LOCKED = (1<<7),
};
struct MilkymistHpdmcState {
SysBusDevice busdev;
uint32_t regs[R_MAX];
};
typedef struct MilkymistHpdmcState MilkymistHpdmcState;
static uint32_t hpdmc_read(void *opaque, target_phys_addr_t addr)
{
MilkymistHpdmcState *s = opaque;
uint32_t r = 0;
addr >>= 2;
switch (addr) {
case R_SYSTEM:
case R_BYPASS:
case R_TIMING:
case R_IODELAY:
r = s->regs[addr];
break;
default:
error_report("milkymist_hpdmc: read access to unknown register 0x"
TARGET_FMT_plx, addr << 2);
break;
}
trace_milkymist_hpdmc_memory_read(addr << 2, r);
return r;
}
static void hpdmc_write(void *opaque, target_phys_addr_t addr, uint32_t value)
{
MilkymistHpdmcState *s = opaque;
trace_milkymist_hpdmc_memory_write(addr, value);
addr >>= 2;
switch (addr) {
case R_SYSTEM:
case R_BYPASS:
case R_TIMING:
s->regs[addr] = value;
break;
case R_IODELAY:
/* ignore writes */
break;
default:
error_report("milkymist_hpdmc: write access to unknown register 0x"
TARGET_FMT_plx, addr << 2);
break;
}
}
static CPUReadMemoryFunc * const hpdmc_read_fn[] = {
NULL,
NULL,
&hpdmc_read,
};
static CPUWriteMemoryFunc * const hpdmc_write_fn[] = {
NULL,
NULL,
&hpdmc_write,
};
static void milkymist_hpdmc_reset(DeviceState *d)
{
MilkymistHpdmcState *s = container_of(d, MilkymistHpdmcState, busdev.qdev);
int i;
for (i = 0; i < R_MAX; i++) {
s->regs[i] = 0;
}
/* defaults */
s->regs[R_IODELAY] = IODELAY_DQSDELAY_RDY | IODELAY_PLL1_LOCKED
| IODELAY_PLL2_LOCKED;
}
static int milkymist_hpdmc_init(SysBusDevice *dev)
{
MilkymistHpdmcState *s = FROM_SYSBUS(typeof(*s), dev);
int hpdmc_regs;
hpdmc_regs = cpu_register_io_memory(hpdmc_read_fn, hpdmc_write_fn, s,
DEVICE_NATIVE_ENDIAN);
sysbus_init_mmio(dev, R_MAX * 4, hpdmc_regs);
return 0;
}
static const VMStateDescription vmstate_milkymist_hpdmc = {
.name = "milkymist-hpdmc",
.version_id = 1,
.minimum_version_id = 1,
.minimum_version_id_old = 1,
.fields = (VMStateField[]) {
VMSTATE_UINT32_ARRAY(regs, MilkymistHpdmcState, R_MAX),
VMSTATE_END_OF_LIST()
}
};
static SysBusDeviceInfo milkymist_hpdmc_info = {
.init = milkymist_hpdmc_init,
.qdev.name = "milkymist-hpdmc",
.qdev.size = sizeof(MilkymistHpdmcState),
.qdev.vmsd = &vmstate_milkymist_hpdmc,
.qdev.reset = milkymist_hpdmc_reset,
};
static void milkymist_hpdmc_register(void)
{
sysbus_register_withprop(&milkymist_hpdmc_info);
}
device_init(milkymist_hpdmc_register)