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/irq.h" 27 #include "hw/sysbus.h" 28 #include "migration/vmstate.h" 29 #include "qemu/module.h" 30 #include "qemu/timer.h" 31 32 #define TYPE_GPIOKEY "gpio-key" 33 #define GPIOKEY(obj) OBJECT_CHECK(GPIOKEYState, (obj), TYPE_GPIOKEY) 34 #define GPIO_KEY_LATENCY 100 /* 100ms */ 35 36 typedef struct GPIOKEYState { 37 SysBusDevice parent_obj; 38 39 QEMUTimer *timer; 40 qemu_irq irq; 41 } GPIOKEYState; 42 43 static const VMStateDescription vmstate_gpio_key = { 44 .name = "gpio-key", 45 .version_id = 1, 46 .minimum_version_id = 1, 47 .fields = (VMStateField[]) { 48 VMSTATE_TIMER_PTR(timer, GPIOKEYState), 49 VMSTATE_END_OF_LIST() 50 } 51 }; 52 53 static void gpio_key_reset(DeviceState *dev) 54 { 55 GPIOKEYState *s = GPIOKEY(dev); 56 57 timer_del(s->timer); 58 } 59 60 static void gpio_key_timer_expired(void *opaque) 61 { 62 GPIOKEYState *s = (GPIOKEYState *)opaque; 63 64 qemu_set_irq(s->irq, 0); 65 timer_del(s->timer); 66 } 67 68 static void gpio_key_set_irq(void *opaque, int irq, int level) 69 { 70 GPIOKEYState *s = (GPIOKEYState *)opaque; 71 72 qemu_set_irq(s->irq, 1); 73 timer_mod(s->timer, 74 qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + GPIO_KEY_LATENCY); 75 } 76 77 static void gpio_key_realize(DeviceState *dev, Error **errp) 78 { 79 GPIOKEYState *s = GPIOKEY(dev); 80 SysBusDevice *sbd = SYS_BUS_DEVICE(dev); 81 82 sysbus_init_irq(sbd, &s->irq); 83 qdev_init_gpio_in(dev, gpio_key_set_irq, 1); 84 s->timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, gpio_key_timer_expired, s); 85 } 86 87 static void gpio_key_class_init(ObjectClass *klass, void *data) 88 { 89 DeviceClass *dc = DEVICE_CLASS(klass); 90 91 dc->realize = gpio_key_realize; 92 dc->vmsd = &vmstate_gpio_key; 93 dc->reset = &gpio_key_reset; 94 } 95 96 static const TypeInfo gpio_key_info = { 97 .name = TYPE_GPIOKEY, 98 .parent = TYPE_SYS_BUS_DEVICE, 99 .instance_size = sizeof(GPIOKEYState), 100 .class_init = gpio_key_class_init, 101 }; 102 103 static void gpio_key_register_types(void) 104 { 105 type_register_static(&gpio_key_info); 106 } 107 108 type_init(gpio_key_register_types) 109