| 1 | /* |
| 2 | * GPIO key |
| 3 | * |
| 4 | * Copyright (c) 2016 Linaro Limited |
| 5 | * |
| 6 | * Author: Shannon Zhao <shannon.zhao@linaro.org> |
| 7 | * |
| 8 | * Emulate a (human) keypress -- when the key is triggered by |
| 9 | * setting the incoming gpio line, the outbound irq line is |
| 10 | * raised for 100ms before being dropped again. |
| 11 | * |
| 12 | * This program is free software; you can redistribute it and/or modify |
| 13 | * it under the terms of the GNU General Public License; either version 2 |
| 14 | * of the License, or (at your option) any later version. |
| 15 | * |
| 16 | * This program is distributed in the hope that it will be useful, |
| 17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 19 | * GNU General Public License for more details. |
| 20 | * |
| 21 | * You should have received a copy of the GNU General Public License along |
| 22 | * with this program; if not, see <http://www.gnu.org/licenses/>. |
| 23 | */ |
| 24 | |
| 25 | #include "qemu/osdep.h" |
| 26 | #include "hw/core/irq.h" |
| 27 | #include "hw/core/sysbus.h" |
| 28 | #include "migration/vmstate.h" |
| 29 | #include "qemu/module.h" |
| 30 | #include "qemu/timer.h" |
| 31 | #include "qom/object.h" |
| 32 | |
| 33 | #define TYPE_GPIOKEY "gpio-key" |
| 34 | OBJECT_DECLARE_SIMPLE_TYPE(GPIOKEYState, GPIOKEY) |
| 35 | #define GPIO_KEY_LATENCY 100 /* 100ms */ |
| 36 | |
| 37 | struct GPIOKEYState { |
| 38 | SysBusDevice parent_obj; |
| 39 | |
| 40 | QEMUTimer *timer; |
| 41 | qemu_irq irq; |
| 42 | }; |
| 43 | |
| 44 | static const VMStateDescription vmstate_gpio_key = { |
| 45 | .name = "gpio-key", |
| 46 | .version_id = 1, |
| 47 | .minimum_version_id = 1, |
| 48 | .fields = (const VMStateField[]) { |
| 49 | VMSTATE_TIMER_PTR(timer, GPIOKEYState), |
| 50 | VMSTATE_END_OF_LIST() |
| 51 | } |
| 52 | }; |
| 53 | |
| 54 | static void gpio_key_reset(DeviceState *dev) |
| 55 | { |
| 56 | GPIOKEYState *s = GPIOKEY(dev); |
| 57 | |
| 58 | timer_del(s->timer); |
| 59 | } |
| 60 | |
| 61 | static void gpio_key_timer_expired(void *opaque) |
| 62 | { |
| 63 | GPIOKEYState *s = (GPIOKEYState *)opaque; |
| 64 | |
| 65 | qemu_set_irq(s->irq, 0); |
| 66 | timer_del(s->timer); |
| 67 | } |
| 68 | |
| 69 | static void gpio_key_set_irq(void *opaque, int irq, int level) |
| 70 | { |
| 71 | GPIOKEYState *s = (GPIOKEYState *)opaque; |
| 72 | |
| 73 | qemu_set_irq(s->irq, 1); |
| 74 | timer_mod(s->timer, |
| 75 | qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + GPIO_KEY_LATENCY); |
| 76 | } |
| 77 | |
| 78 | static void gpio_key_realize(DeviceState *dev, Error **errp) |
| 79 | { |
| 80 | GPIOKEYState *s = GPIOKEY(dev); |
| 81 | SysBusDevice *sbd = SYS_BUS_DEVICE(dev); |
| 82 | |
| 83 | sysbus_init_irq(sbd, &s->irq); |
| 84 | qdev_init_gpio_in(dev, gpio_key_set_irq, 1); |
| 85 | s->timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, gpio_key_timer_expired, s); |
| 86 | } |
| 87 | |
| 88 | static void gpio_key_class_init(ObjectClass *klass, const void *data) |
| 89 | { |
| 90 | DeviceClass *dc = DEVICE_CLASS(klass); |
| 91 | |
| 92 | dc->realize = gpio_key_realize; |
| 93 | dc->vmsd = &vmstate_gpio_key; |
| 94 | device_class_set_legacy_reset(dc, gpio_key_reset); |
| 95 | } |
| 96 | |
| 97 | static const TypeInfo gpio_key_info = { |
| 98 | .name = TYPE_GPIOKEY, |
| 99 | .parent = TYPE_SYS_BUS_DEVICE, |
| 100 | .instance_size = sizeof(GPIOKEYState), |
| 101 | .class_init = gpio_key_class_init, |
| 102 | }; |
| 103 | |
| 104 | static void gpio_key_register_types(void) |
| 105 | { |
| 106 | type_register_static(&gpio_key_info); |
| 107 | } |
| 108 | |
| 109 | type_init(gpio_key_register_types) |