qemu-e2k/hw/misc/imx2_wdt.c

91 lines
2.4 KiB
C
Raw Normal View History

/*
* Copyright (c) 2018, Impinj, Inc.
*
* i.MX2 Watchdog IP block
*
* Author: Andrey Smirnov <andrew.smirnov@gmail.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "qemu/bitops.h"
#include "qemu/module.h"
#include "sysemu/watchdog.h"
#include "hw/misc/imx2_wdt.h"
#define IMX2_WDT_WCR_WDA BIT(5) /* -> External Reset WDOG_B */
#define IMX2_WDT_WCR_SRS BIT(4) /* -> Software Reset Signal */
static uint64_t imx2_wdt_read(void *opaque, hwaddr addr,
unsigned int size)
{
return 0;
}
static void imx2_wdt_write(void *opaque, hwaddr addr,
uint64_t value, unsigned int size)
{
if (addr == IMX2_WDT_WCR &&
(value & (IMX2_WDT_WCR_WDA | IMX2_WDT_WCR_SRS))) {
watchdog_perform_action();
}
}
static const MemoryRegionOps imx2_wdt_ops = {
.read = imx2_wdt_read,
.write = imx2_wdt_write,
.endianness = DEVICE_NATIVE_ENDIAN,
.impl = {
/*
* Our device would not work correctly if the guest was doing
* unaligned access. This might not be a limitation on the
* real device but in practice there is no reason for a guest
* to access this device unaligned.
*/
.min_access_size = 4,
.max_access_size = 4,
.unaligned = false,
},
};
static void imx2_wdt_realize(DeviceState *dev, Error **errp)
{
IMX2WdtState *s = IMX2_WDT(dev);
memory_region_init_io(&s->mmio, OBJECT(dev),
&imx2_wdt_ops, s,
TYPE_IMX2_WDT".mmio",
IMX2_WDT_REG_NUM * sizeof(uint16_t));
sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->mmio);
}
static void imx2_wdt_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->realize = imx2_wdt_realize;
set_bit(DEVICE_CATEGORY_MISC, dc->categories);
}
static const TypeInfo imx2_wdt_info = {
.name = TYPE_IMX2_WDT,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(IMX2WdtState),
.class_init = imx2_wdt_class_init,
};
static WatchdogTimerModel model = {
.wdt_name = "imx2-watchdog",
.wdt_description = "i.MX2 Watchdog",
};
static void imx2_wdt_register_type(void)
{
watchdog_add_model(&model);
type_register_static(&imx2_wdt_info);
}
type_init(imx2_wdt_register_type)