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 #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, void *data) 89 { 90 DeviceClass *dc = DEVICE_CLASS(klass); 91 92 dc->realize = gpio_key_realize; 93 dc->vmsd = &vmstate_gpio_key; 94 dc->reset = &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) 110