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 typedef struct GPIOKEYState GPIOKEYState; 35 #define GPIOKEY(obj) OBJECT_CHECK(GPIOKEYState, (obj), TYPE_GPIOKEY) 36 #define GPIO_KEY_LATENCY 100 /* 100ms */ 37 38 struct GPIOKEYState { 39 SysBusDevice parent_obj; 40 41 QEMUTimer *timer; 42 qemu_irq irq; 43 }; 44 45 static const VMStateDescription vmstate_gpio_key = { 46 .name = "gpio-key", 47 .version_id = 1, 48 .minimum_version_id = 1, 49 .fields = (VMStateField[]) { 50 VMSTATE_TIMER_PTR(timer, GPIOKEYState), 51 VMSTATE_END_OF_LIST() 52 } 53 }; 54 55 static void gpio_key_reset(DeviceState *dev) 56 { 57 GPIOKEYState *s = GPIOKEY(dev); 58 59 timer_del(s->timer); 60 } 61 62 static void gpio_key_timer_expired(void *opaque) 63 { 64 GPIOKEYState *s = (GPIOKEYState *)opaque; 65 66 qemu_set_irq(s->irq, 0); 67 timer_del(s->timer); 68 } 69 70 static void gpio_key_set_irq(void *opaque, int irq, int level) 71 { 72 GPIOKEYState *s = (GPIOKEYState *)opaque; 73 74 qemu_set_irq(s->irq, 1); 75 timer_mod(s->timer, 76 qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + GPIO_KEY_LATENCY); 77 } 78 79 static void gpio_key_realize(DeviceState *dev, Error **errp) 80 { 81 GPIOKEYState *s = GPIOKEY(dev); 82 SysBusDevice *sbd = SYS_BUS_DEVICE(dev); 83 84 sysbus_init_irq(sbd, &s->irq); 85 qdev_init_gpio_in(dev, gpio_key_set_irq, 1); 86 s->timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, gpio_key_timer_expired, s); 87 } 88 89 static void gpio_key_class_init(ObjectClass *klass, void *data) 90 { 91 DeviceClass *dc = DEVICE_CLASS(klass); 92 93 dc->realize = gpio_key_realize; 94 dc->vmsd = &vmstate_gpio_key; 95 dc->reset = &gpio_key_reset; 96 } 97 98 static const TypeInfo gpio_key_info = { 99 .name = TYPE_GPIOKEY, 100 .parent = TYPE_SYS_BUS_DEVICE, 101 .instance_size = sizeof(GPIOKEYState), 102 .class_init = gpio_key_class_init, 103 }; 104 105 static void gpio_key_register_types(void) 106 { 107 type_register_static(&gpio_key_info); 108 } 109 110 type_init(gpio_key_register_types) 111