gate_x86.c

《嵌入式Linux－硬件

/*
 * gate_x86 v1.0 11/25/01
 * www.embeddedlinuxinterfacing.com
 *
 * The original location of this code is
 * http://www.embeddedlinuxinterfacing.com/chapters/11/
 * Copyright (C) 2001 by Craig Hollabaugh
 *
 * This program is free software; you can redistribute it and/or modify 
 * it under the terms of the GNU Library General Public License as 
 * published by the Free Software Foundation; either version 2 of the 
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but 
 * WITHOUT ANY WARRANTY; without even the implied warranty of 
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public 
 * License along with this program; if not, write to the 
 * Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

/*
gcc -O2 -D__KERNEL__ -DMODULE -I/usr/src/linux/include -c gate_x86.c -o gate_x86.o
*/


#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/tqueue.h>
#include <linux/delay.h>

#define MODULE_VERSION "1.0"
#define MODULE_NAME "gate"

static struct proc_dir_entry *gate_file;

#define SPPDATAPORT         0x378
#define SPPSTATUSPORT       (SPPDATAPORT + 1)
#define SPPCONTROLPORT      (SPPDATAPORT + 2)
#define SSPINTERRUPTENABLE  0x10
#define STROBE              0x01

static int proc_read_gate(char *page, char **start, off_t off, int count, int *eof, void *data)
{
	int len;

	outb(0x00,SPPDATAPORT);
	udelay(100);
	outb(0x80,SPPDATAPORT);
	outb(0x00,SPPDATAPORT);

	return 0;
}

static int __init init_gate(void)
{
	int rv = 0;

/* create gate file */
	gate_file = create_proc_entry("gate", 0666, NULL);
	if(gate_file == NULL) {
		rv = -ENOMEM;
		goto out;
	}
	
	gate_file->data = NULL;
	gate_file->read_proc = &proc_read_gate;
	gate_file->write_proc = NULL;
	gate_file->owner = THIS_MODULE;

	/* everything OK */
	printk(KERN_INFO "%s %s initialized\n",MODULE_NAME, MODULE_VERSION);
	return 0;
	

out:
	return rv;
}


static void __exit cleanup_gate(void)
{
	remove_proc_entry("gate", NULL);
	
	printk(KERN_INFO "%s %s removed\n", MODULE_NAME, MODULE_VERSION);
}

module_init(init_gate);
module_exit(cleanup_gate);

MODULE_AUTHOR("Craig Hollabaugh");
MODULE_DESCRIPTION("gate proc module");

EXPORT_NO_SYMBOLS;