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/sysbus.h" 27 #include "qemu/module.h" 28 #include "qemu/timer.h" 29 30 #define TYPE_GPIOKEY "gpio-key" 31 #define GPIOKEY(obj) OBJECT_CHECK(GPIOKEYState, (obj), TYPE_GPIOKEY) 32 #define GPIO_KEY_LATENCY 100 /* 100ms */ 33 34 typedef struct GPIOKEYState { 35 SysBusDevice parent_obj; 36 37 QEMUTimer *timer; 38 qemu_irq irq; 39 } GPIOKEYState; 40 41 static const VMStateDescription vmstate_gpio_key = { 42 .name = "gpio-key", 43 .version_id = 1, 44 .minimum_version_id = 1, 45 .fields = (VMStateField[]) { 46 VMSTATE_TIMER_PTR(timer, GPIOKEYState), 47 VMSTATE_END_OF_LIST() 48 } 49 }; 50 51 static void gpio_key_reset(DeviceState *dev) 52 { 53 GPIOKEYState *s = GPIOKEY(dev); 54 55 timer_del(s->timer); 56 } 57 58 static void gpio_key_timer_expired(void *opaque) 59 { 60 GPIOKEYState *s = (GPIOKEYState *)opaque; 61 62 qemu_set_irq(s->irq, 0); 63 timer_del(s->timer); 64 } 65 66 static void gpio_key_set_irq(void *opaque, int irq, int level) 67 { 68 GPIOKEYState *s = (GPIOKEYState *)opaque; 69 70 qemu_set_irq(s->irq, 1); 71 timer_mod(s->timer, 72 qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + GPIO_KEY_LATENCY); 73 } 74 75 static void gpio_key_realize(DeviceState *dev, Error **errp) 76 { 77 GPIOKEYState *s = GPIOKEY(dev); 78 SysBusDevice *sbd = SYS_BUS_DEVICE(dev); 79 80 sysbus_init_irq(sbd, &s->irq); 81 qdev_init_gpio_in(dev, gpio_key_set_irq, 1); 82 s->timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, gpio_key_timer_expired, s); 83 } 84 85 static void gpio_key_class_init(ObjectClass *klass, void *data) 86 { 87 DeviceClass *dc = DEVICE_CLASS(klass); 88 89 dc->realize = gpio_key_realize; 90 dc->vmsd = &vmstate_gpio_key; 91 dc->reset = &gpio_key_reset; 92 } 93 94 static const TypeInfo gpio_key_info = { 95 .name = TYPE_GPIOKEY, 96 .parent = TYPE_SYS_BUS_DEVICE, 97 .instance_size = sizeof(GPIOKEYState), 98 .class_init = gpio_key_class_init, 99 }; 100 101 static void gpio_key_register_types(void) 102 { 103 type_register_static(&gpio_key_info); 104 } 105 106 type_init(gpio_key_register_types) 107