cdcether.c

S3C2440ARM9开发板的USB驱动程序

			// is using this device, so we will go ahead and give up.
			return -1;
		}
	}
	// We made it all the way through.
	// I guess no one has claimed any of these interfaces.
	return 0;
}

//////////////////////////////////////////////////////////////////////////////
// Routines to ask for and set the kernel network interface's MAC address ////
// Used by driver's probe routine ////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////

static inline unsigned char hex2dec( unsigned char digit )
{
	/* Is there a standard way to do this??? */
	/* I have written this code TOO MANY times. */
	if ( (digit >= '0') && (digit <= '9') )	{
		return (digit - '0');
	}
	if ( (digit >= 'a') && (digit <= 'f') )	{
		return (digit - 'a' + 10);
	}
	if ( (digit >= 'A') && (digit <= 'F') )	{
		return (digit - 'A' + 10);
	}
	return 16;
}

/* CDC Ethernet devices provide the MAC address as a string */
/* We get an index to the string in the Ethernet functional header */
/* This routine retrieves the string, sanity checks it, and sets the */
/* MAC address in the network device */
/* The encoding is a bit wacky - see CDC Spec Table 41 for details */
static void set_ethernet_addr( ether_dev_t *ether_dev )
{
	unsigned char	mac_addr[6];
	int		i;
	int 		len;
	unsigned char	buffer[13];

	/* Let's assume we don't get anything */
	mac_addr[0] = 0x00;
	mac_addr[1] = 0x00;
	mac_addr[2] = 0x00;
	mac_addr[3] = 0x00;
	mac_addr[4] = 0x00;
	mac_addr[5] = 0x00;

	/* Let's ask the device */
	if (0 > (len = usb_string(ether_dev->usb, ether_dev->iMACAddress, buffer, 13))) {
		err("Attempting to get MAC address failed: %d", -1*len);
		return;
	}

	/* Sanity check */
	if (len != 12)	{
		/* You gotta love failing sanity checks */
		err("Attempting to get MAC address returned %d bytes", len);
		return;
	}

	/* Fill in the mac_addr */
	for (i = 0; i < 6; i++)	{
		if ((16 == buffer[2 * i]) || (16 == buffer[2 * i + 1])) {
			err("Bad value in MAC address");
		}
		else {
			mac_addr[i] = ( hex2dec( buffer[2 * i] ) << 4 ) + hex2dec( buffer[2 * i + 1] );
		}
	}

	/* Now copy it over to our network device structure */
	memcpy( ether_dev->net->dev_addr, mac_addr, sizeof(mac_addr) );
}

//////////////////////////////////////////////////////////////////////////////
// Routine to print to syslog information about the driver ///////////////////
// Used by driver's probe routine ////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////

void log_device_info(ether_dev_t *ether_dev)
{
	int len;
	int string_num;
	unsigned char manu[256];
	unsigned char prod[256];
	unsigned char sern[256];
	unsigned char *mac_addr;

	/* Default empty strings in case we don't find a real one */
	manu[0] = 0x00;
	prod[0] = 0x00;
	sern[0] = 0x00;

	/*  Try to get the device Manufacturer */
	string_num = ether_dev->usb->descriptor.iManufacturer;
	if (string_num)	{
		// Put it into its buffer
		len = usb_string(ether_dev->usb, string_num, manu, 255);
		// Just to be safe
		manu[len] = 0x00;
	}

	/* Try to get the device Product Name */
	string_num = ether_dev->usb->descriptor.iProduct;
	if (string_num)	{
		// Put it into its buffer
		len = usb_string(ether_dev->usb, string_num, prod, 255);
		// Just to be safe
		prod[len] = 0x00;
	}

	/* Try to get the device Serial Number */
	string_num = ether_dev->usb->descriptor.iSerialNumber;
	if (string_num)	{
		// Put it into its buffer
		len = usb_string(ether_dev->usb, string_num, sern, 255);
		// Just to be safe
		sern[len] = 0x00;
	}

	/* This makes it easier for us to print */
	mac_addr = ether_dev->net->dev_addr;

	/* Now send everything we found to the syslog */
	info( "%s: %s %s %s", ether_dev->net->name, manu, prod, sern);
	dbg( "%s: %02X:%02X:%02X:%02X:%02X:%02X",
		ether_dev->net->name,
		mac_addr[0],
		mac_addr[1],
		mac_addr[2],
		mac_addr[3],
		mac_addr[4],
		mac_addr[5] );

}

/* Forward declaration */
static struct usb_driver CDCEther_driver ;

//////////////////////////////////////////////////////////////////////////////
// Module's probe routine ////////////////////////////////////////////////////
// claims interfaces if they are for an Ethernet CDC /////////////////////////
//////////////////////////////////////////////////////////////////////////////

static void * CDCEther_probe( struct usb_device *usb, unsigned int ifnum,
			     const struct usb_device_id *id)
{
	struct net_device	*net;
	ether_dev_t		*ether_dev;
	int 			rc;

	// First we should check the active configuration to see if 
	// any other driver has claimed any of the interfaces.
	if ( check_for_claimed_interfaces( usb->actconfig ) ) {
		// Someone has already put there grubby paws on this device.
		// We don't want it now...
		return NULL;
	}

	// We might be finding a device we can use.
	// We all go ahead and allocate our storage space.
	// We need to because we have to start filling in the data that
	// we are going to need later.
	if(!(ether_dev = kmalloc(sizeof(ether_dev_t), GFP_KERNEL))) {
		err("out of memory allocating device structure");
		return NULL;
	}

	// Zero everything out.
	memset(ether_dev, 0, sizeof(ether_dev_t));

	// Let's see if we can find a configuration we can use.
	rc = find_valid_configuration( usb, ether_dev );
	if (rc)	{
		// Nope we couldn't find one we liked.
		// This device was not meant for us to control.
		kfree( ether_dev );
		return	NULL;
	}

	// Now that we FOUND a configuration. let's try to make the 
	// device go into it.
	if ( usb_set_configuration( usb, ether_dev->bConfigurationValue ) ) {
		err("usb_set_configuration() failed");
		kfree( ether_dev );
		return NULL;
	}

	// Now set the communication interface up as required.
	if (usb_set_interface(usb, ether_dev->comm_bInterfaceNumber, ether_dev->comm_bAlternateSetting)) {
		err("usb_set_interface() failed");
		kfree( ether_dev );
		return NULL;
	}

	// Only turn traffic on right now if we must...
	if (ether_dev->data_interface_altset_num_without_traffic >= 0)	{
		// We found an alternate setting for the data
		// interface that allows us to turn off traffic.
		// We should use it.
		if (usb_set_interface( usb, 
		                       ether_dev->data_bInterfaceNumber, 
		                       ether_dev->data_bAlternateSetting_without_traffic)) {
			err("usb_set_interface() failed");
			kfree( ether_dev );
			return NULL;
		}
	} else	{
		// We didn't find an alternate setting for the data
		// interface that would let us turn off traffic.
		// Oh well, let's go ahead and do what we must...
		if (usb_set_interface( usb, 
		                       ether_dev->data_bInterfaceNumber, 
		                       ether_dev->data_bAlternateSetting_with_traffic)) {
			err("usb_set_interface() failed");
			kfree( ether_dev );
			return NULL;
		}
	}

	// Now we need to get a kernel Ethernet interface.
	net = init_etherdev( NULL, 0 );
	if ( !net ) {
		// Hmm...  The kernel is not sharing today...
		// Fine, we didn't want it anyway...
		err( "Unable to initialize ethernet device" );
		kfree( ether_dev );
		return	NULL;
	}

	// Now that we have an ethernet device, let's set it up
	// (And I don't mean "set [it] up the bomb".)
	net->priv = ether_dev;
	SET_MODULE_OWNER(net);
	net->open = CDCEther_open;
	net->stop = CDCEther_close;
	net->watchdog_timeo = CDC_ETHER_TX_TIMEOUT;
	net->tx_timeout = CDCEther_tx_timeout;   // TX timeout function
	net->do_ioctl = CDCEther_ioctl;
	net->hard_start_xmit = CDCEther_start_xmit;
	net->set_multicast_list = CDCEther_set_multicast;
	net->get_stats = CDCEther_netdev_stats;
	net->mtu = ether_dev->wMaxSegmentSize - 14;

	// We'll keep track of this information for later...
	ether_dev->usb = usb;
	ether_dev->net = net;
	
	// and don't forget the MAC address.
	set_ethernet_addr( ether_dev );

	// Send a message to syslog about what we are handling
	log_device_info( ether_dev );

	/* We need to manually claim the data interface, while the comm interface gets claimed in the return */
	usb_driver_claim_interface( &CDCEther_driver, 
	                            &(usb->config[ether_dev->configuration_num].interface[ether_dev->data_interface]), 
	                            ether_dev );

	// Does this REALLY do anything???
	usb_inc_dev_use( usb );

	// Okay, we are finally done...
	return ether_dev;
}


//////////////////////////////////////////////////////////////////////////////
// Module's disconnect routine ///////////////////////////////////////////////
// Called when the driver is unloaded or the device is unplugged /////////////
// (Whichever happens first assuming the driver suceeded at its probe) ///////
//////////////////////////////////////////////////////////////////////////////

static void CDCEther_disconnect( struct usb_device *usb, void *ptr )
{
	ether_dev_t *ether_dev = ptr;

	// Sanity check!!!
	if ( !ether_dev || !ether_dev->usb ) {
		// We failed.  We are insane!!!
		warn("unregistering non-existant device");
		return;
	}

	// Make sure we fail the sanity check if we try this again.
	ether_dev->usb = NULL;
	
	// It is possible that this function is called before
	// the "close" function.
	// This tells the close function we are already disconnected
	ether_dev->flags |= CDC_ETHER_UNPLUG;
	
	// We don't need the network device any more
	unregister_netdev( ether_dev->net );
	
	// For sanity checks
	ether_dev->net = NULL;

	// I ask again, does this do anything???
	usb_dec_dev_use( usb );

	// We are done with this interface
	usb_driver_release_interface( &CDCEther_driver, 
	                              &(usb->config[ether_dev->configuration_num].interface[ether_dev->comm_interface]) );

	// We are done with this interface too
	usb_driver_release_interface( &CDCEther_driver, 
	                              &(usb->config[ether_dev->configuration_num].interface[ether_dev->data_interface]) );

	// No more tied up kernel memory
	kfree( ether_dev );
	
	// This does no good, but it looks nice!
	ether_dev = NULL;
}

//////////////////////////////////////////////////////////////////////////////
// Driver info ///////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////

static struct usb_driver CDCEther_driver = {
	name:		"CDCEther",
	probe:		CDCEther_probe,
	disconnect:	CDCEther_disconnect,
	id_table:	CDCEther_ids,
};

//////////////////////////////////////////////////////////////////////////////
// init and exit routines called when driver is installed and uninstalled ////
//////////////////////////////////////////////////////////////////////////////

int __init CDCEther_init(void)
{
	dbg( "%s", version );
	return usb_register( &CDCEther_driver );
}

void __exit CDCEther_exit(void)
{
	usb_deregister( &CDCEther_driver );
}

//////////////////////////////////////////////////////////////////////////////
// Module info ///////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////

module_init( CDCEther_init );
module_exit( CDCEther_exit );

MODULE_AUTHOR("Brad Hards and another");
MODULE_DESCRIPTION("USB CDC Ethernet driver");
MODULE_LICENSE("GPL");

MODULE_DEVICE_TABLE (usb, CDCEther_ids);
MODULE_PARM (multicast_filter_limit, "i");
MODULE_PARM_DESC (multicast_filter_limit, "CDCEther maximum number of filtered multicast addresses");

//////////////////////////////////////////////////////////////////////////////
// End of file ///////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////