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