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 | |