magic-key.c

基于ARM9的LINUX下的按键驱动程序

/*
****************************************Copyright (c)**************************************************
**                               Guangzhou Zhiyuan Electronic Co.,LTD.
**                                     graduate school
**                                 http://www.zyinside.com
**
**------------------------------------- File Info ------------------------------------------------------
** File name:           magic-key.c
** Last modified Date:  2005-12-28
** Last Version:        1.0
** Descriptions:        Driver for KEY1 on MagicARM2410.
**                      Based on Linux 2.4.18. 
**------------------------------------------------------------------------------------------------------
** Created by:          Chenxibing
** Created date:        2005-12-27
** Version:             1.0
** Descriptions:        Preliminary version.
**
**------------------------------------------------------------------------------------------------------
** Modified by:
** Modified date:
** Version:
** Descriptions:
**
********************************************************************************************************
*/
#ifndef __KERNEL__
	#define __KERNEL__
#endif

#ifndef MODULE
	#define MODULE
#endif

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/poll.h>
#include <linux/spinlock.h>
#include <linux/irq.h>
#include <linux/wait.h>
//#include <linux/devfs_fs_kernel.h>

//#include <linux/miscdevice.h>
//#include <linux/delay.h>

#include <asm/hardware.h>

#define DEVICE_NAME	"magic-key"
#define KEY_MAJOR 	231	// can be 231~239 or 240~254

MODULE_LICENSE("Proprietary");
MODULE_DESCRIPTION("Guangzhou Zhiyuan Electronic Co.,LTD.\ngraduate school\nhttp://www.zyinside.com");
MODULE_SUPPORTED_DEVICE("Linux 2.4.18 & MagicARM2410");
MODULE_AUTHOR("Chenxibing");

/*
*******************************************************************************************************
** Information of KEY1.
*******************************************************************************************************
*/

static struct key_info
{
	int 		irq_num;
	unsigned int 	gpio_port;
	int 		key_num;
} key1[1] =
{
	{ IRQ_EINT4, GPIO_F4, 1 },
};

static int key_value = 0;
static int ready = 0;
/*
*******************************************************************************************************
** Function name: key_irq()
** Descriptions	: key1's irq handler.
**		: for request_irq() and free_irq().
** handler prototype:
**		: void (*handler)(int irq, void *dev_id, struct pt_regs*).
** Input:
**      irq	: irq number. 
**	dev_id	: private data.
**	pt_regs	: seldom use.
** Output:
**	return	: NONE.
** Created by	: Chenxibing
** Created Date	: 2005-12-27
**-----------------------------------------------------------------------------------------------------
** Modified by	:
** Modified Date: 
**-----------------------------------------------------------------------------------------------------
*******************************************************************************************************
*/
static DECLARE_WAIT_QUEUE_HEAD(key_wait);

static void key_irq_handle(int irq, void *dev_id, struct pt_regs *reg)
{
	struct key_info *key;
	key = key1;

        key_value = key->key_num;
	ready = 1;
	wake_up_interruptible(&key_wait);
}

/*
*******************************************************************************************************
** Function name: magic_key_read()
** Descriptions	: read key1's value.
** Input:
**      filp	: pointer of file
**	buf	: buf for save data
**	count	: size of read
	f_ops	: *p_ops = read point
** Output:
**	return	: read size
** Created by	: Chenxibing
** Created Date	: 2005-12-27
**-----------------------------------------------------------------------------------------------------
** Modified by	:
** Modified Date: 
**-----------------------------------------------------------------------------------------------------
*******************************************************************************************************
*/
static ssize_t magic_key_read(struct file *filp, char * buf, size_t count, loff_t *f_pos)
{
	static int value;

	wait_event_interruptible(key_wait, ready == 1);
//	interruptible_sleep_on(&key_wait);

	if(count != sizeof(key_value))
		return -EINVAL;

	value = key_value;
        copy_to_user(buf, &value, sizeof(value));
	ready = 0;
	
        return sizeof(value);
}

/*
*******************************************************************************************************
** Function name: magic_key_open()
** Descriptions	: open key
** Input:
**	inode	: information of device
**      filp	: pointer of file
** Output:
**	0	: OK
**    	other	: not OK
** Created by	: Chenxibing
** Created Date	: 2005-12-27
**-----------------------------------------------------------------------------------------------------
** Modified by	:
** Modified Date: 
**-----------------------------------------------------------------------------------------------------
*******************************************************************************************************
*/

static int magic_key_open(struct inode *inode, struct file *filp)
{
	int result;
	struct key_info *key;

	ready = 0;
	key = key1;
	set_external_irq(key->irq_num, EXT_FALLING_EDGE, GPIO_PULLUP_DIS);

	result = request_irq(key->irq_num, key_irq_handle, SA_INTERRUPT, DEVICE_NAME, NULL);
	if(result)
	{
		printk(KERN_INFO DEVICE_NAME " Failed to request irq.\n");
		return result;
	}

	MOD_INC_USE_COUNT;
	printk(KERN_INFO DEVICE_NAME ": opened.\n");
	return 0;
}

/*
*******************************************************************************************************
** Function name: magic_key_release()
** Descriptions	: release KEY1
** Input:
**	inode	: information of device
**      filp	: pointer of file
** Output:
**	0	: OK
**    	other	: not OK
** Created by	: Chenxibing
** Created Date	: 2005-12-27
**-----------------------------------------------------------------------------------------------------
** Modified by	:
** Modified Date: 
**-----------------------------------------------------------------------------------------------------
*******************************************************************************************************
*/
static int magic_key_release(struct inode *inode, struct file *filp)
{
	struct key_info *key;

	key = key1;
	free_irq(key->irq_num, NULL);

	MOD_DEC_USE_COUNT;
	printk(KERN_INFO DEVICE_NAME ": released.\n");
	return 0;
}


/*
*******************************************************************************************************
**                                    operations of the driver
*******************************************************************************************************
*/
static struct file_operations magic_key_fops =
{
	owner:	THIS_MODULE,
	read: 	magic_key_read,
	open:	magic_key_open,
	release:	magic_key_release,
};


/*
*******************************************************************************************************
** Function name: magic_key_init()
** Descriptions	: register driver
** Input:
**		: NONE
** Output:
**	0	: OK
**    	other	: not OK
** Created by	: Chenxibing
** Created Date	: 2005-12-27
**-----------------------------------------------------------------------------------------------------
** Modified by	:
** Modified Date: 
**-----------------------------------------------------------------------------------------------------
*******************************************************************************************************
*/
static devfs_handle_t devfs_handle;
static int __init magic_key_init(void)
{
//	int result;

//	result = register_chrdev(KEY_MAJOR, DEVICE_NAME, &magic_key_fops);
//	if(result<0)
//	{
//		printk(KERN_INFO "Failed to register major: " DEVICE_NAME ".\n");
//		return result;
//	}

	devfs_handle = devfs_register(NULL, DEVICE_NAME, DEVFS_FL_DEFAULT,		KEY_MAJOR, 0, S_IFCHR | S_IRUSR | S_IWUSR, &magic_key_fops, NULL);

	return 0;
}

/*
*******************************************************************************************************
** Function name: magic_key_exit()
** Descriptions	: unregister driver
** Input:
**		: NONE
** Output:
**	0	: OK
**    	other	: not OK
** Created by	: Chenxibing
** Created Date	: 2005-12-27
**-----------------------------------------------------------------------------------------------------
** Modified by	:
** Modified Date: 
**-----------------------------------------------------------------------------------------------------
*******************************************************************************************************
*/
static void __exit magic_key_exit(void)
{
	devfs_unregister(devfs_handle);
//	unregister_chrdev(KEY_MAJOR, DEVICE_NAME);
}

module_init(magic_key_init);
module_exit(magic_key_exit);