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 DECLARE_INSTANCE_CHECKER(GPIOKEYState, GPIOKEY, 36 TYPE_GPIOKEY) 37 #define GPIO_KEY_LATENCY 100 /* 100ms */ 38 39 struct GPIOKEYState { 40 SysBusDevice parent_obj; 41 42 QEMUTimer *timer; 43 qemu_irq irq; 44 }; 45 46 static const VMStateDescription vmstate_gpio_key = { 47 .name = "gpio-key", 48 .version_id = 1, 49 .minimum_version_id = 1, 50 .fields = (VMStateField[]) { 51 VMSTATE_TIMER_PTR(timer, GPIOKEYState), 52 VMSTATE_END_OF_LIST() 53 } 54 }; 55 56 static void gpio_key_reset(DeviceState *dev) 57 { 58 GPIOKEYState *s = GPIOKEY(dev); 59 60 timer_del(s->timer); 61 } 62 63 static void gpio_key_timer_expired(void *opaque) 64 { 65 GPIOKEYState *s = (GPIOKEYState *)opaque; 66 67 qemu_set_irq(s->irq, 0); 68 timer_del(s->timer); 69 } 70 71 static void gpio_key_set_irq(void *opaque, int irq, int level) 72 { 73 GPIOKEYState *s = (GPIOKEYState *)opaque; 74 75 qemu_set_irq(s->irq, 1); 76 timer_mod(s->timer, 77 qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + GPIO_KEY_LATENCY); 78 } 79 80 static void gpio_key_realize(DeviceState *dev, Error **errp) 81 { 82 GPIOKEYState *s = GPIOKEY(dev); 83 SysBusDevice *sbd = SYS_BUS_DEVICE(dev); 84 85 sysbus_init_irq(sbd, &s->irq); 86 qdev_init_gpio_in(dev, gpio_key_set_irq, 1); 87 s->timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, gpio_key_timer_expired, s); 88 } 89 90 static void gpio_key_class_init(ObjectClass *klass, void *data) 91 { 92 DeviceClass *dc = DEVICE_CLASS(klass); 93 94 dc->realize = gpio_key_realize; 95 dc->vmsd = &vmstate_gpio_key; 96 dc->reset = &gpio_key_reset; 97 } 98 99 static const TypeInfo gpio_key_info = { 100 .name = TYPE_GPIOKEY, 101 .parent = TYPE_SYS_BUS_DEVICE, 102 .instance_size = sizeof(GPIOKEYState), 103 .class_init = gpio_key_class_init, 104 }; 105 106 static void gpio_key_register_types(void) 107 { 108 type_register_static(&gpio_key_info); 109 } 110 111 type_init(gpio_key_register_types) 112