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authorShannon Zhao <shannon.zhao@linaro.org>2016-03-30 17:27:22 +0100
committerPeter Maydell <peter.maydell@linaro.org>2016-03-30 17:27:22 +0100
commite5a8152c9bfd3d40c37711ba5b704f277cbc0c54 (patch)
treef934ee17be4817f0f357bafa37dc498f3048ffd0 /hw/gpio/gpio_key.c
parent489ef4c810033e63af570c8a430af8b9858bfa5f (diff)
hw/gpio: Add the emulation of gpio_key
This will be used by ARM virt machine as a power button. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Message-id: 1458221140-15232-2-git-send-email-zhaoshenglong@huawei.com [PMM: Use hyphen rather than underscore in type names; add a comment briefly describing what the device does] Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'hw/gpio/gpio_key.c')
-rw-r--r--hw/gpio/gpio_key.c104
1 files changed, 104 insertions, 0 deletions
diff --git a/hw/gpio/gpio_key.c b/hw/gpio/gpio_key.c
new file mode 100644
index 0000000000..ef287727b6
--- /dev/null
+++ b/hw/gpio/gpio_key.c
@@ -0,0 +1,104 @@
+/*
+ * 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/sysbus.h"
+
+#define TYPE_GPIOKEY "gpio-key"
+#define GPIOKEY(obj) OBJECT_CHECK(GPIOKEYState, (obj), TYPE_GPIOKEY)
+#define GPIO_KEY_LATENCY 100 /* 100ms */
+
+typedef struct GPIOKEYState {
+ SysBusDevice parent_obj;
+
+ QEMUTimer *timer;
+ qemu_irq irq;
+} GPIOKEYState;
+
+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)