qemu-e2k/hw/gpio/gpio_key.c

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/*
* GPIO key
*
* Copyright (c) 2016 Linaro Limited
*
* Author: Shannon Zhao <shannon.zhao@linaro.org>
*
* Emulate a (human) keypress -- when the key is triggered by
* setting the incoming gpio line, the outbound irq line is
* raised for 100ms before being dropped again.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License; 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.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "hw/irq.h"
#include "hw/sysbus.h"
#include "migration/vmstate.h"
#include "qemu/module.h"
#include "qemu/timer.h"
#include "qom/object.h"
#define TYPE_GPIOKEY "gpio-key"
typedef struct GPIOKEYState GPIOKEYState;
DECLARE_INSTANCE_CHECKER(GPIOKEYState, GPIOKEY,
TYPE_GPIOKEY)
#define GPIO_KEY_LATENCY 100 /* 100ms */
struct GPIOKEYState {
SysBusDevice parent_obj;
QEMUTimer *timer;
qemu_irq irq;
};
static const VMStateDescription vmstate_gpio_key = {
.name = "gpio-key",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_TIMER_PTR(timer, GPIOKEYState),
VMSTATE_END_OF_LIST()
}
};
static void gpio_key_reset(DeviceState *dev)
{
GPIOKEYState *s = GPIOKEY(dev);
timer_del(s->timer);
}
static void gpio_key_timer_expired(void *opaque)
{
GPIOKEYState *s = (GPIOKEYState *)opaque;
qemu_set_irq(s->irq, 0);
timer_del(s->timer);
}
static void gpio_key_set_irq(void *opaque, int irq, int level)
{
GPIOKEYState *s = (GPIOKEYState *)opaque;
qemu_set_irq(s->irq, 1);
timer_mod(s->timer,
qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + GPIO_KEY_LATENCY);
}
static void gpio_key_realize(DeviceState *dev, Error **errp)
{
GPIOKEYState *s = GPIOKEY(dev);
SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
sysbus_init_irq(sbd, &s->irq);
qdev_init_gpio_in(dev, gpio_key_set_irq, 1);
s->timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, gpio_key_timer_expired, s);
}
static void gpio_key_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->realize = gpio_key_realize;
dc->vmsd = &vmstate_gpio_key;
dc->reset = &gpio_key_reset;
}
static const TypeInfo gpio_key_info = {
.name = TYPE_GPIOKEY,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(GPIOKEYState),
.class_init = gpio_key_class_init,
};
static void gpio_key_register_types(void)
{
type_register_static(&gpio_key_info);
}
type_init(gpio_key_register_types)