1 /* fakekey.c
2 * Functions for simulating keypresses.
3 *
4 * Copyright (C) 2010 the Speakup Team
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 */
16 #include <linux/types.h>
17 #include <linux/slab.h>
18 #include <linux/preempt.h>
19 #include <linux/percpu.h>
20 #include <linux/input.h>
21
22 #include "speakup.h"
23
24 #define PRESSED 1
25 #define RELEASED 0
26
27 static DEFINE_PER_CPU(int, reporting_keystroke);
28
29 static struct input_dev *virt_keyboard;
30
speakup_add_virtual_keyboard(void)31 int speakup_add_virtual_keyboard(void)
32 {
33 int err;
34
35 virt_keyboard = input_allocate_device();
36
37 if (!virt_keyboard)
38 return -ENOMEM;
39
40 virt_keyboard->name = "Speakup";
41 virt_keyboard->id.bustype = BUS_VIRTUAL;
42 virt_keyboard->phys = "speakup/input0";
43 virt_keyboard->dev.parent = NULL;
44
45 __set_bit(EV_KEY, virt_keyboard->evbit);
46 __set_bit(KEY_DOWN, virt_keyboard->keybit);
47
48 err = input_register_device(virt_keyboard);
49 if (err) {
50 input_free_device(virt_keyboard);
51 virt_keyboard = NULL;
52 }
53
54 return err;
55 }
56
speakup_remove_virtual_keyboard(void)57 void speakup_remove_virtual_keyboard(void)
58 {
59 if (virt_keyboard != NULL) {
60 input_unregister_device(virt_keyboard);
61 virt_keyboard = NULL;
62 }
63 }
64
65 /*
66 * Send a simulated down-arrow to the application.
67 */
speakup_fake_down_arrow(void)68 void speakup_fake_down_arrow(void)
69 {
70 unsigned long flags;
71
72 /* disable keyboard interrupts */
73 local_irq_save(flags);
74 /* don't change CPU */
75 preempt_disable();
76
77 __this_cpu_write(reporting_keystroke, true);
78 input_report_key(virt_keyboard, KEY_DOWN, PRESSED);
79 input_report_key(virt_keyboard, KEY_DOWN, RELEASED);
80 input_sync(virt_keyboard);
81 __this_cpu_write(reporting_keystroke, false);
82
83 /* reenable preemption */
84 preempt_enable();
85 /* reenable keyboard interrupts */
86 local_irq_restore(flags);
87 }
88
89 /*
90 * Are we handling a simulated keypress on the current CPU?
91 * Returns a boolean.
92 */
speakup_fake_key_pressed(void)93 bool speakup_fake_key_pressed(void)
94 {
95 return this_cpu_read(reporting_keystroke);
96 }
97