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