simple_key.c

这是关于linux下的驱动程序的一段加锁程序

/*
 * $Id$
 * EAX-400 linux实验指导书配套实验代码
 * 实验2.3 mini键盘(一个简单的单按键驱动程序)
 * Copyright (c) 2006 Beijing EFLAG Technology Co.,LTD
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU 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 General Public License for more details.
 *
 * You should have received a copy of the GNU 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 
 */
 
#include <linux/config.h>
#ifndef __KERNEL__
  #define __KERNEL__
#endif
#ifndef MODULE
  #define MODULE
#endif
#include <linux/input.h>
#include <linux/module.h>
#include <linux/init.h>
#include <asm/irq.h>
#include <asm/io.h>

#define SIMPLE_KEY_GPIO		17
#define SIMPLE_KEY_IRQ		IRQ_GPIO(SIMPLE_KEY_GPIO)
#define SIMPLE_KEY_PORT		0x40000000	/* 需要根据事件设置修改 */

static struct input_dev simple_key_dev = {
	name:		"simple key",	
	idversion:	0x0100,
};

static void simple_key_interrupt(int irq, void *dummy, struct pt_regs *fp)
{
	/* 报告事件发生 */
	input_report_key(&simple_key_dev, KEY_1, inb(SIMPLE_KEY_PORT) & 1);
}

static int __init simple_key_init(void)
{
	if (request_irq(SIMPLE_KEY_IRQ, simple_key_interrupt, 0, "simple key", NULL)) {
                printk(KERN_ERR "simple_key.c: Can't allocate irq %d\n", SIMPLE_KEY_IRQ);
                return -EBUSY;
        }
		
	simple_key_dev.evbit[0] = BIT(EV_KEY);	/* 设备产生的事件类型 */
	simple_key_dev.keybit[LONG(KEY_1)] = BIT(KEY_1);/* 设备支持的按键 */	
	
	input_register_device(&simple_key_dev);
	
	return 0;
}

static void __exit simple_key_exit(void)
{
        input_unregister_device(&simple_key_dev);
	free_irq(SIMPLE_KEY_IRQ, simple_key_interrupt);
}

module_init(simple_key_init);
module_exit(simple_key_exit);
MODULE_LICENSE("GPL");