linux/drivers/accessibility/braille/braille_console.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Minimalistic braille device kernel support.
 *
 * By default, shows console messages on the braille device.
 * Pressing Insert switches to VC browsing.
 *
 *  Copyright (C) Samuel Thibault <[email protected]>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/console.h>
#include <linux/notifier.h>

#include <linux/selection.h>
#include <linux/vt_kern.h>
#include <linux/consolemap.h>

#include <linux/keyboard.h>
#include <linux/kbd_kern.h>
#include <linux/input.h>

MODULE_AUTHOR(…) …;
MODULE_DESCRIPTION(…) …;

/*
 * Braille device support part.
 */

/* Emit various sounds */
static bool sound;
module_param(sound, bool, 0);
MODULE_PARM_DESC(…) …;

static void beep(unsigned int freq)
{ … }

/* mini console */
#define WIDTH …
#define BRAILLE_KEY …
static u16 console_buf[WIDTH];
static int console_cursor;

/* mini view of VC */
static int vc_x, vc_y, lastvc_x, lastvc_y;

/* show console ? (or show VC) */
static int console_show = …;
/* pending newline ? */
static int console_newline = …;
static int lastVC = …;

static struct console *braille_co;

/* Very VisioBraille-specific */
static void braille_write(u16 *buf)
{ … }

/* Follow the VC cursor*/
static void vc_follow_cursor(struct vc_data *vc)
{ … }

/* Maybe the VC cursor moved, if so follow it */
static void vc_maybe_cursor_moved(struct vc_data *vc)
{ … }

/* Show portion of VC at vc_x, vc_y */
static void vc_refresh(struct vc_data *vc)
{ … }

/*
 * Link to keyboard
 */

static int keyboard_notifier_call(struct notifier_block *blk,
				  unsigned long code, void *_param)
{ … }

static struct notifier_block keyboard_notifier_block = …;

static int vt_notifier_call(struct notifier_block *blk,
			    unsigned long code, void *_param)
{ … }

static struct notifier_block vt_notifier_block = …;

/*
 * Called from printk.c when console=brl is given
 */

int braille_register_console(struct console *console, int index,
		char *console_options, char *braille_options)
{ … }

int braille_unregister_console(struct console *console)
{ … }