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 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19 */
20#include <linux/types.h>
21#include <linux/slab.h>
22#include <linux/preempt.h>
23#include <linux/percpu.h>
24#include <linux/input.h>
25
26#include "speakup.h"
27
28#define PRESSED 1
29#define RELEASED 0
30
31static DEFINE_PER_CPU(bool, reporting_keystroke);
32
33static struct input_dev *virt_keyboard;
34
35int speakup_add_virtual_keyboard(void)
36{
37	int err;
38
39	virt_keyboard = input_allocate_device();
40
41	if (!virt_keyboard)
42		return -ENOMEM;
43
44	virt_keyboard->name = "Speakup";
45	virt_keyboard->id.bustype = BUS_VIRTUAL;
46	virt_keyboard->phys = "speakup/input0";
47	virt_keyboard->dev.parent = NULL;
48
49	__set_bit(EV_KEY, virt_keyboard->evbit);
50	__set_bit(KEY_DOWN, virt_keyboard->keybit);
51
52	err = input_register_device(virt_keyboard);
53	if (err) {
54		input_free_device(virt_keyboard);
55		virt_keyboard = NULL;
56	}
57
58	return err;
59}
60
61void speakup_remove_virtual_keyboard(void)
62{
63	if (virt_keyboard != NULL) {
64		input_unregister_device(virt_keyboard);
65		virt_keyboard = NULL;
66	}
67}
68
69/*
70	 * Send a simulated down-arrow to the application.
71	 */
72void speakup_fake_down_arrow(void)
73{
74	unsigned long flags;
75
76	/* disable keyboard interrupts */
77	local_irq_save(flags);
78	/* don't change CPU */
79	preempt_disable();
80
81	__this_cpu_write(reporting_keystroke, true);
82	input_report_key(virt_keyboard, KEY_DOWN, PRESSED);
83	input_report_key(virt_keyboard, KEY_DOWN, RELEASED);
84	input_sync(virt_keyboard);
85	__this_cpu_write(reporting_keystroke, false);
86
87	/* reenable preemption */
88	preempt_enable();
89	/* reenable keyboard interrupts */
90	local_irq_restore(flags);
91}
92
93/*
94	 * Are we handling a simulated keypress on the current CPU?
95	 * Returns a boolean.
96	 */
97bool speakup_fake_key_pressed(void)
98{
99	return this_cpu_read(reporting_keystroke);
100}
101