LXR linux/drivers/staging/speakup/fakekey.c

   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        __this_cpu_write(reporting_keystroke, false);
  85
  86        /* reenable preemption */
  87        preempt_enable();
  88        /* reenable keyboard interrupts */
  89        local_irq_restore(flags);
  90}
  91
  92/*
  93         * Are we handling a simulated keypress on the current CPU?
  94         * Returns a boolean.
  95         */
  96bool speakup_fake_key_pressed(void)
  97{
  98        return this_cpu_read(reporting_keystroke);
  99}
 100