//-------------------------------------------------------------------
//	nicstatus.c
//
//	This module creates a pseudo-file in the '/proc' directory
//	that lets a user display the current value in the 'STATUS'
//	register of our Intel 82573L Network Interface controller.  
//	
//		to compile:  $ mmake nicstatus
//		to install:  $ /sbin/insmod nicstatus.ko
//		to execute:  $ cat /proc/nicstatus
//		and remove:  $ /sbin/rmmod nicstatus
//
//	NOTE: Written and tested with Linux kernel version 2.6.26.
//
//	programmer: ALLAN CRUSE
//	written on: 23 APR 2009
//-------------------------------------------------------------------

#include <linux/module.h>	// for init_module() 
#include <linux/proc_fs.h>	// for create_proc_read_entry() 
#include <linux/pci.h>		// for pci_get_device()

#define VENDOR_ID	0x8086	// Intel Corporation
#define DEVICE_ID	0x109A	// 82573L controller

char modname[] = "nicstatus";
struct pci_dev	*devp = NULL;
unsigned int	iobase;

const char *duplex[] = { "half", "full" };
const char *state[] = { "DOWN", "UP" };
const char *speed[] = { "10Mbps", "100Mbps", "1000Mbps", "?" };

int 
my_proc( char *buf, char **start, off_t off, int count, int *eof, void *data ) 
{
	int	status, len;		// declare local variables

	// obtain the NIC's 'status' 
	outl( 0x0008, iobase+0 ); 	// specify register to access
	status = inl( iobase+4 );	// input the register's value

	// create the pseudo-file's contents
	len = sprintf( buf, "\n E1000_STATUS=%08X ", status );
	len += sprintf( buf+len, " speed=%s,", speed[ (status >> 6)&3 ] );
	len += sprintf( buf+len, " %s-duplex,", duplex[ (status >> 0)&1 ] );
	len += sprintf( buf+len, " nic is %s ",  state[ (status >> 1)&1 ] );
	len += sprintf( buf+len, "\n\n" );

	// set End-Of-File flag, and return the pseudo-file's length
	*eof = 1;
	return	len;
}



static int __init nicstatus_init( void )
{
	// append a confirmation-message to the system log 
	printk( "<1>\nInstalling \'%s\' module\n", modname );

	// detect the device's presence
	devp = pci_get_device( VENDOR_ID, DEVICE_ID, devp );
	if ( !devp ) return -ENODEV;

	// get the device's I/O-port base-address
	iobase = pci_resource_start( devp, 2 );

	// create our pseudo-file in the '/proc' subdirectory
	create_proc_read_entry( modname, 0, NULL, my_proc, NULL );
	return	0;  //SUCCESS
}


static void __exit nicstatus_exit(void )
{
	// detete our pseudo-file
	remove_proc_entry( modname, NULL );

	// append a confirmation-message to the system log 
	printk( "<1>Removing \'%s\' module\n", modname );
}

module_init( nicstatus_init );
module_exit( nicstatus_exit );
MODULE_LICENSE("GPL");