patch-2.4.0-test3 linux/drivers/usb/storage/usb.c

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diff -u --recursive --new-file v2.4.0-test2/linux/drivers/usb/storage/usb.c linux/drivers/usb/storage/usb.c
@@ -0,0 +1,803 @@
+/* Driver for USB Mass Storage compliant devices
+ *
+ * $Id: usb.c,v 1.3 2000/06/27 10:20:39 mdharm Exp $
+ *
+ * Current development and maintainance by:
+ *   (c) 1999, 2000 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
+ *
+ * Developed with the assistance of:
+ *   (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org)
+ *
+ * Initial work by:
+ *   (c) 1999 Michael Gee (michael@linuxspecific.com)
+ *
+ * This driver is based on the 'USB Mass Storage Class' document. This
+ * describes in detail the protocol used to communicate with such
+ * devices.  Clearly, the designers had SCSI and ATAPI commands in
+ * mind when they created this document.  The commands are all very
+ * similar to commands in the SCSI-II and ATAPI specifications.
+ *
+ * It is important to note that in a number of cases this class
+ * exhibits class-specific exemptions from the USB specification.
+ * Notably the usage of NAK, STALL and ACK differs from the norm, in
+ * that they are used to communicate wait, failed and OK on commands.
+ *
+ * Also, for certain devices, the interrupt endpoint is used to convey
+ * status of a command.
+ *
+ * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
+ * information about this driver.
+ *
+ * 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, 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.,
+ * 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "usb.h"
+#include "scsiglue.h"
+#include "transport.h"
+#include "protocol.h"
+#include "debug.h"
+
+#include <linux/module.h>
+ /*FIXME: note that this next include is needed for the new sleeping system
+  * which is not implemented yet
+  */
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/malloc.h>
+
+/*
+ * Per device data
+ */
+
+static int my_host_number;
+
+/*
+ * kernel thread actions
+ */
+
+#define US_ACT_COMMAND		1
+#define US_ACT_DEVICE_RESET	2
+#define US_ACT_BUS_RESET	3
+#define US_ACT_HOST_RESET	4
+#define US_ACT_EXIT		5
+
+/* The list of structures and the protective lock for them */
+struct us_data *us_list;
+struct semaphore us_list_semaphore;
+
+static void * storage_probe(struct usb_device *dev, unsigned int ifnum);
+static void storage_disconnect(struct usb_device *dev, void *ptr);
+static struct usb_driver storage_driver = {
+	name:		"usb-storage",
+	probe:		storage_probe,
+	disconnect:	storage_disconnect,
+};
+
+static int usb_stor_control_thread(void * __us)
+{
+	struct us_data *us = (struct us_data *)__us;
+	int action;
+
+	lock_kernel();
+
+	/*
+	 * This thread doesn't need any user-level access,
+	 * so get rid of all our resources..
+	 */
+	daemonize();
+
+	/* set our name for identification purposes */
+	sprintf(current->comm, "usb-storage-%d", us->host_number);
+
+	unlock_kernel();
+
+	/* signal that we've started the thread */
+	up(&(us->notify));
+
+	for(;;) {
+		US_DEBUGP("*** thread sleeping.\n");
+		down(&(us->sleeper));
+		down(&(us->queue_exclusion));
+		US_DEBUGP("*** thread awakened.\n");
+
+		/* take the command off the queue */
+		action = us->action;
+		us->action = 0;
+		us->srb = us->queue_srb;
+	
+		/* release the queue lock as fast as possible */
+		up(&(us->queue_exclusion));
+
+		switch (action) {
+		case US_ACT_COMMAND:
+			/* reject if target != 0 or if LUN is higher than
+			 * the maximum known LUN
+			 */
+			if (us->srb->target || (us->srb->lun > us->max_lun)) {
+				US_DEBUGP("Bad device number (%d/%d)\n",
+					  us->srb->target, us->srb->lun);
+
+				us->srb->result = DID_BAD_TARGET << 16;
+
+				us->srb->scsi_done(us->srb);
+				us->srb = NULL;
+				break;
+			}
+
+			/* handle those devices which can't do a START_STOP */
+			if ((us->srb->cmnd[0] == START_STOP) &&
+			    (us->flags & US_FL_START_STOP)) {
+				us->srb->result = GOOD;
+				us->srb->scsi_done(us->srb);
+				us->srb = NULL;
+				break;
+			}
+				     
+			/* lock the device pointers */
+			down(&(us->dev_semaphore));
+
+			/* our device has gone - pretend not ready */
+			if (!us->pusb_dev) {
+				US_DEBUGP("Request is for removed device\n");
+				/* For REQUEST_SENSE, it's the data.  But
+				 * for anything else, it should look like
+				 * we auto-sensed for it.
+				 */
+				if (us->srb->cmnd[0] == REQUEST_SENSE) {
+					memcpy(us->srb->request_buffer, 
+					       usb_stor_sense_notready, 
+					       sizeof(usb_stor_sense_notready));
+					us->srb->result = GOOD;
+				} else {
+					memcpy(us->srb->sense_buffer, 
+					       usb_stor_sense_notready, 
+					       sizeof(usb_stor_sense_notready));
+					us->srb->result = CHECK_CONDITION;
+				}
+			} else { /* !us->pusb_dev */
+				/* we've got a command, let's do it! */
+				US_DEBUG(usb_stor_show_command(us->srb));
+				us->proto_handler(us->srb, us);
+			}
+
+			/* unlock the device pointers */
+			up(&(us->dev_semaphore));
+
+			/* indicate that the command is done */
+			if (us->srb->result != DID_ABORT << 16) {
+				US_DEBUGP("scsi cmd done, result=0x%x\n", 
+					   us->srb->result);
+				us->srb->scsi_done(us->srb);
+			} else {
+				US_DEBUGP("scsi command aborted\n");
+				up(&(us->notify));
+			}
+			us->srb = NULL;
+			break;
+
+		case US_ACT_DEVICE_RESET:
+			break;
+
+		case US_ACT_BUS_RESET:
+			break;
+
+		case US_ACT_HOST_RESET:
+			break;
+
+		} /* end switch on action */
+
+		/* exit if we get a signal to exit */
+		if (action == US_ACT_EXIT) {
+			US_DEBUGP("-- US_ACT_EXIT command recieved\n");
+			break;
+		}
+	} /* for (;;) */
+
+	/* notify the exit routine that we're actually exiting now */
+	up(&(us->notify));
+
+	return 0;
+}	
+
+/* This is the list of devices we recognize, along with their flag data */
+static struct us_unusual_dev us_unusual_dev_list[] = {
+	{ 0x03f0, 0x0107, 0x0200, 0x0200, "HP USB CD-Writer Plus",
+		US_SC_8070, US_PR_CB, 0}, 
+	{ 0x04e6, 0x0001, 0x0200, 0x0200, "Matshita LS-120",
+		US_SC_8020, US_PR_CB, US_FL_SINGLE_LUN},
+	{ 0x04e6, 0x0002, 0x0100, 0x0100, "Shuttle eUSCSI Bridge",
+		US_SC_SCSI, US_PR_BULK, US_FL_ALT_LENGTH}, 
+	{ 0x04e6, 0x0006, 0x0100, 0x0100, "Shuttle eUSB MMC Adapter",
+		US_SC_SCSI, US_PR_CB, US_FL_SINGLE_LUN}, 
+	{ 0x054c, 0x0010, 0x0210, 0x0210, "Sony DSC-S30/S70", 
+		US_SC_SCSI, US_PR_CB, US_FL_SINGLE_LUN | US_FL_START_STOP |
+		US_FL_MODE_XLATE | US_FL_ALT_LENGTH | US_FL_ALT_LENGTH},
+	{ 0x054c, 0x002d, 0x0100, 0x0100, "Sony Memorystick MSAC-US1",
+		US_SC_SCSI, US_PR_CB, US_FL_SINGLE_LUN | US_FL_START_STOP |
+		US_FL_MODE_XLATE | US_FL_ALT_LENGTH},
+	{ 0x057b, 0x0000, 0x0000, 0x0299, "Y-E Data Flashbuster-U",
+		US_SC_UFI,  US_PR_CB, US_FL_SINGLE_LUN},
+	{ 0x057b, 0x0000, 0x0300, 0x9999, "Y-E Data Flashbuster-U",
+		US_SC_UFI,  US_PR_CBI, US_FL_SINGLE_LUN},
+	{ 0x0693, 0x0002, 0x0100, 0x0100, "Hagiwara FlashGate SmartMedia",
+		US_SC_SCSI, US_PR_BULK, US_FL_ALT_LENGTH},
+	{ 0x0781, 0x0001, 0x0200, 0x0200, "Sandisk ImageMate (SDDR-01)",
+		US_SC_SCSI, US_PR_CB, US_FL_SINGLE_LUN | US_FL_START_STOP},
+	{ 0x0781, 0x0002, 0x0009, 0x0009, "Sandisk Imagemate (SDDR-31)",
+		US_SC_SCSI, US_PR_BULK, US_FL_IGNORE_SER},
+	{ 0x07af, 0x0004, 0x0100, 0x0100, "Microtech USB-SCSI-DB25",
+		US_SC_SCSI, US_PR_BULK, US_FL_ALT_LENGTH}, 
+	{ 0x07af, 0x0005, 0x0100, 0x0100, "Microtech USB-SCSI-HD50",
+		US_SC_SCSI, US_PR_BULK, US_FL_ALT_LENGTH}, 
+	{ 0x05ab, 0x0031, 0x0100, 0x0100, "In-System USB/IDE Bridge",
+		US_SC_8070, US_PR_BULK, US_FL_ALT_LENGTH}, 
+	{ 0x0693, 0x0005, 0x0100, 0x0100, "Hagiwara Flashgate",
+		US_SC_SCSI, US_PR_BULK, US_FL_ALT_LENGTH}, 
+	{ 0 }};
+
+/* Search our ususual device list, based on vendor/product combinations
+ * to see if we can support this device.  Returns a pointer to a structure
+ * defining how we should support this device, or NULL if it's not in the
+ * list
+ */
+static struct us_unusual_dev* us_find_dev(u16 idVendor, u16 idProduct, 
+					  u16 bcdDevice)
+{
+	struct us_unusual_dev* ptr;
+
+	US_DEBUGP("Searching unusual device list for (0x%x, 0x%x, 0x%x)...\n",
+		  idVendor, idProduct, bcdDevice);
+
+	ptr = us_unusual_dev_list;
+	while ((ptr->idVendor != 0x0000) && 
+	       !((ptr->idVendor == idVendor) && 
+		 (ptr->idProduct == idProduct) &&
+		 (ptr->bcdDeviceMin <= bcdDevice) &&
+		 (ptr->bcdDeviceMax >= bcdDevice)))
+		ptr++;
+	
+	/* if the search ended because we hit the end record, we failed */
+	if (ptr->idVendor == 0x0000) {
+		US_DEBUGP("-- did not find a matching device\n");
+		return NULL;
+	}
+
+	/* otherwise, we found one! */
+	US_DEBUGP("-- found matching device: %s\n", ptr->name);
+	return ptr;
+}
+
+/* Set up the IRQ pipe and handler
+ * Note that this function assumes that all the data in the us_data
+ * strucuture is current.  This includes the ep_int field, which gives us
+ * the endpoint for the interrupt.
+ * Returns non-zero on failure, zero on success
+ */ 
+static int usb_stor_allocate_irq(struct us_data *ss)
+{
+	unsigned int pipe;
+	int maxp;
+	int result;
+
+	US_DEBUGP("Allocating IRQ for CBI transport\n");
+	
+	/* lock access to the data structure */
+	down(&(ss->irq_urb_sem));
+
+	/* allocate the URB */
+	ss->irq_urb = usb_alloc_urb(0);
+	if (!ss->irq_urb) {
+		up(&(ss->irq_urb_sem));
+		US_DEBUGP("couldn't allocate interrupt URB");
+		return 1;
+	}
+	
+	/* calculate the pipe and max packet size */
+	pipe = usb_rcvintpipe(ss->pusb_dev, ss->ep_int->bEndpointAddress & 
+			      USB_ENDPOINT_NUMBER_MASK);
+	maxp = usb_maxpacket(ss->pusb_dev, pipe, usb_pipeout(pipe));
+	if (maxp > sizeof(ss->irqbuf))
+		maxp = sizeof(ss->irqbuf);
+	
+	/* fill in the URB with our data */
+	FILL_INT_URB(ss->irq_urb, ss->pusb_dev, pipe, ss->irqbuf, maxp, 
+		     usb_stor_CBI_irq, ss, ss->ep_int->bInterval); 
+	
+	/* submit the URB for processing */
+	result = usb_submit_urb(ss->irq_urb);
+	US_DEBUGP("usb_submit_urb() returns %d\n", result);
+	if (result) {
+		usb_free_urb(ss->irq_urb);
+		up(&(ss->irq_urb_sem));
+		return 2;
+	}
+
+	/* unlock the data structure and return success */
+	up(&(ss->irq_urb_sem));
+	return 0;
+}
+
+/* Probe to see if a new device is actually a SCSI device */
+static void * storage_probe(struct usb_device *dev, unsigned int ifnum)
+{
+	int i;
+	char mf[USB_STOR_STRING_LEN];		     /* manufacturer */
+	char prod[USB_STOR_STRING_LEN];		     /* product */
+	char serial[USB_STOR_STRING_LEN];	     /* serial number */
+	GUID(guid);			   /* Global Unique Identifier */
+	unsigned int flags;
+	struct us_unusual_dev *unusual_dev;
+	struct us_data *ss = NULL;
+	int result;
+
+	/* these are temporary copies -- we test on these, then put them
+	 * in the us-data structure 
+	 */
+	struct usb_endpoint_descriptor *ep_in = NULL;
+	struct usb_endpoint_descriptor *ep_out = NULL;
+	struct usb_endpoint_descriptor *ep_int = NULL;
+	u8 subclass = 0;
+	u8 protocol = 0;
+
+	/* the altsettting 0 on the interface we're probing */
+	struct usb_interface_descriptor *altsetting = 
+		&(dev->actconfig->interface[ifnum].altsetting[0]); 
+
+	/* clear the temporary strings */
+	memset(mf, 0, sizeof(mf));
+	memset(prod, 0, sizeof(prod));
+	memset(serial, 0, sizeof(serial));
+
+	/* search for this device in our unusual device list */
+	unusual_dev = us_find_dev(dev->descriptor.idVendor, 
+				  dev->descriptor.idProduct,
+				  dev->descriptor.bcdDevice);
+
+	/* 
+	 * Can we support this device, either because we know about it
+	 * from our unusual device list, or because it advertises that it's
+	 * compliant to the specification?
+	 */
+	if (!unusual_dev &&
+	    !(dev->descriptor.bDeviceClass == 0 &&
+	      altsetting->bInterfaceClass == USB_CLASS_MASS_STORAGE &&
+	      altsetting->bInterfaceSubClass >= US_SC_MIN &&
+	      altsetting->bInterfaceSubClass <= US_SC_MAX)) {
+		/* if it's not a mass storage, we go no further */
+		return NULL;
+	}
+
+	/* At this point, we know we've got a live one */
+	US_DEBUGP("USB Mass Storage device detected\n");
+
+	/* Determine subclass and protocol, or copy from the interface */
+	if (unusual_dev) {
+		subclass = unusual_dev->useProtocol;
+		protocol = unusual_dev->useTransport;
+		flags = unusual_dev->flags;
+	} else {
+		subclass = altsetting->bInterfaceSubClass;
+		protocol = altsetting->bInterfaceProtocol;
+		flags = 0;
+	}
+	
+	/*
+	 * Find the endpoints we need
+	 * We are expecting a minimum of 2 endpoints - in and out (bulk).
+	 * An optional interrupt is OK (necessary for CBI protocol).
+	 * We will ignore any others.
+	 */
+	for (i = 0; i < altsetting->bNumEndpoints; i++) {
+		/* is it an BULK endpoint? */
+		if ((altsetting->endpoint[i].bmAttributes & 
+		     USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_BULK) {
+			/* BULK in or out? */
+			if (altsetting->endpoint[i].bEndpointAddress & 
+			    USB_DIR_IN)
+				ep_in = &altsetting->endpoint[i];
+			else
+				ep_out = &altsetting->endpoint[i];
+		}
+
+		/* is it an interrupt endpoint? */
+		if ((altsetting->endpoint[i].bmAttributes & 
+		     USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT) {
+			ep_int = &altsetting->endpoint[i];
+		}
+	}
+	US_DEBUGP("Endpoints: In: 0x%p Out: 0x%p Int: 0x%p (Period %d)\n",
+		  ep_in, ep_out, ep_int, ep_int ? ep_int->bInterval : 0);
+
+	/* set the interface -- STALL is an acceptable response here */
+	result = usb_set_interface(dev, altsetting->bInterfaceNumber, 0);
+	US_DEBUGP("Result from usb_set_interface is %d\n", result);
+	if (result == -EPIPE) {
+		US_DEBUGP("-- clearing stall on control interface\n");
+		usb_clear_halt(dev, usb_sndctrlpipe(dev, 0));
+	} else if (result != 0) {
+		/* it's not a stall, but another error -- time to bail */
+		US_DEBUGP("-- Unknown error.  Rejecting device\n");
+		return NULL;
+	}
+
+	/* Do some basic sanity checks, and bail if we find a problem */
+	if (!ep_in || !ep_out || (protocol == US_PR_CBI && !ep_int)) {
+		US_DEBUGP("Sanity check failed.	 Rejecting device.\n");
+		return NULL;
+	}
+
+	/* At this point, we're committed to using the device */
+
+	/* clear the GUID and fetch the strings */
+	GUID_CLEAR(guid);
+	if (dev->descriptor.iManufacturer)
+		usb_string(dev, dev->descriptor.iManufacturer, 
+			   mf, sizeof(mf));
+	if (dev->descriptor.iProduct)
+		usb_string(dev, dev->descriptor.iProduct, 
+			   prod, sizeof(prod));
+	if (dev->descriptor.iSerialNumber && !(flags & US_FL_IGNORE_SER))
+		usb_string(dev, dev->descriptor.iSerialNumber, 
+			   serial, sizeof(serial));
+	
+	/* Create a GUID for this device */
+	if (dev->descriptor.iSerialNumber && serial[0]) {
+		/* If we have a serial number, and it's a non-NULL string */
+		make_guid(guid, dev->descriptor.idVendor, 
+			  dev->descriptor.idProduct, serial);
+	} else {
+		/* We don't have a serial number, so we use 0 */
+		make_guid(guid, dev->descriptor.idVendor, 
+			  dev->descriptor.idProduct, "0");
+	}
+
+	/* lock access to the data structures */
+	down(&us_list_semaphore);
+
+	/*
+	 * Now check if we have seen this GUID before
+	 * We're looking for a device with a matching GUID that isn't
+	 * allready on the system
+	 */
+	ss = us_list;
+	while ((ss != NULL) && 
+	       ((ss->pusb_dev) || !GUID_EQUAL(guid, ss->guid)))
+		ss = ss->next;
+
+	if (ss != NULL) {
+		/* Existing device -- re-connect */
+		US_DEBUGP("Found existing GUID " GUID_FORMAT "\n",
+			  GUID_ARGS(guid));
+
+		/* establish the connection to the new device upon reconnect */
+		ss->ifnum = ifnum;
+		ss->pusb_dev = dev;
+	
+		/* copy over the endpoint data */
+		if (ep_in)
+			ss->ep_in = ep_in->bEndpointAddress & 
+				USB_ENDPOINT_NUMBER_MASK;
+		if (ep_out)
+			ss->ep_out = ep_out->bEndpointAddress & 
+				USB_ENDPOINT_NUMBER_MASK;
+		ss->ep_int = ep_int;
+
+		/* allocate an IRQ callback if one is needed */
+		if ((ss->protocol == US_PR_CBI) && usb_stor_allocate_irq(ss))
+			return NULL;
+	} else { 
+		/* New device -- allocate memory and initialize */
+		US_DEBUGP("New GUID " GUID_FORMAT "\n", GUID_ARGS(guid));
+	
+		if ((ss = (struct us_data *)kmalloc(sizeof(struct us_data), 
+						    GFP_KERNEL)) == NULL) {
+			printk(KERN_WARNING USB_STORAGE "Out of memory\n");
+			up(&us_list_semaphore);
+			return NULL;
+		}
+		memset(ss, 0, sizeof(struct us_data));
+
+		/* allocate the URB we're going to use */
+		ss->current_urb = usb_alloc_urb(0);
+		if (!ss->current_urb) {
+			kfree(ss);
+			return NULL;
+		}
+
+		/* Initialize the mutexes only when the struct is new */
+		init_MUTEX_LOCKED(&(ss->sleeper));
+		init_MUTEX_LOCKED(&(ss->notify));
+		init_MUTEX_LOCKED(&(ss->ip_waitq));
+		init_MUTEX(&(ss->queue_exclusion));
+		init_MUTEX(&(ss->irq_urb_sem));
+		init_MUTEX(&(ss->current_urb_sem));
+		init_MUTEX(&(ss->dev_semaphore));
+
+		/* copy over the subclass and protocol data */
+		ss->subclass = subclass;
+		ss->protocol = protocol;
+		ss->flags = flags;
+
+		/* copy over the endpoint data */
+		if (ep_in)
+			ss->ep_in = ep_in->bEndpointAddress & 
+				USB_ENDPOINT_NUMBER_MASK;
+		if (ep_out)
+			ss->ep_out = ep_out->bEndpointAddress & 
+				USB_ENDPOINT_NUMBER_MASK;
+		ss->ep_int = ep_int;
+
+		/* establish the connection to the new device */
+		ss->ifnum = ifnum;
+		ss->pusb_dev = dev;
+
+		/* copy over the identifiying strings */
+		strncpy(ss->vendor, mf, USB_STOR_STRING_LEN);
+		strncpy(ss->product, prod, USB_STOR_STRING_LEN);
+		strncpy(ss->serial, serial, USB_STOR_STRING_LEN);
+		if (strlen(ss->vendor) == 0)
+			strncpy(ss->vendor, "Unknown", USB_STOR_STRING_LEN);
+		if (strlen(ss->product) == 0)
+			strncpy(ss->product, "Unknown", USB_STOR_STRING_LEN);
+		if (strlen(ss->serial) == 0)
+			strncpy(ss->serial, "None", USB_STOR_STRING_LEN);
+
+		/* copy the GUID we created before */
+		memcpy(ss->guid, guid, sizeof(guid));
+		
+		/* 
+		 * Set the handler pointers based on the protocol
+		 * Again, this data is persistant across reattachments
+		 */
+		switch (ss->protocol) {
+		case US_PR_CB:
+			ss->transport_name = "Control/Bulk";
+			ss->transport = usb_stor_CB_transport;
+			ss->transport_reset = usb_stor_CB_reset;
+			ss->max_lun = 7;
+			break;
+			
+		case US_PR_CBI:
+			ss->transport_name = "Control/Bulk/Interrupt";
+			ss->transport = usb_stor_CBI_transport;
+			ss->transport_reset = usb_stor_CB_reset;
+			ss->max_lun = 7;
+			break;
+			
+		case US_PR_BULK:
+			ss->transport_name = "Bulk";
+			ss->transport = usb_stor_Bulk_transport;
+			ss->transport_reset = usb_stor_Bulk_reset;
+			ss->max_lun = usb_stor_Bulk_max_lun(ss);
+			break;
+			
+		default:
+			ss->transport_name = "Unknown";
+			up(&us_list_semaphore);
+			kfree(ss->current_urb);
+			kfree(ss);
+			return NULL;
+			break;
+		}
+		US_DEBUGP("Transport: %s\n", ss->transport_name);
+
+		/* fix for single-lun devices */
+		if (ss->flags & US_FL_SINGLE_LUN)
+			ss->max_lun = 0;
+
+		switch (ss->subclass) {
+		case US_SC_RBC:
+			ss->protocol_name = "Reduced Block Commands (RBC)";
+			ss->proto_handler = usb_stor_transparent_scsi_command;
+			break;
+
+		case US_SC_8020:
+			ss->protocol_name = "8020i";
+			ss->proto_handler = usb_stor_ATAPI_command;
+			break;
+
+		case US_SC_QIC:
+			ss->protocol_name = "QIC-157";
+			US_DEBUGP("Sorry, device not supported.	 Please\n");
+			US_DEBUGP("contact mdharm-usb@one-eyed-alien.net\n");
+			US_DEBUGP("if you see this message.\n");
+			up(&us_list_semaphore);
+			kfree(ss->current_urb);
+			kfree(ss);
+			return NULL;
+			break;
+
+		case US_SC_8070:
+			ss->protocol_name = "8070i";
+			ss->proto_handler = usb_stor_ATAPI_command;
+			break;
+
+		case US_SC_SCSI:
+			ss->protocol_name = "Transparent SCSI";
+			ss->proto_handler = usb_stor_transparent_scsi_command;
+			break;
+
+		case US_SC_UFI:
+			ss->protocol_name = "Uniform Floppy Interface (UFI)";
+			ss->proto_handler = usb_stor_ufi_command;
+			break;
+
+		default:
+			ss->protocol_name = "Unknown";
+			up(&us_list_semaphore);
+			kfree(ss->current_urb);
+			kfree(ss);
+			return NULL;
+			break;
+		}
+		US_DEBUGP("Protocol: %s\n", ss->protocol_name);
+
+		/* allocate an IRQ callback if one is needed */
+		if ((ss->protocol == US_PR_CBI) && usb_stor_allocate_irq(ss))
+			return NULL;
+		
+		/*
+		 * Since this is a new device, we need to generate a scsi 
+		 * host definition, and register with the higher SCSI layers
+		 */
+
+		/* Initialize the host template based on the default one */
+		memcpy(&(ss->htmplt), &usb_stor_host_template, 
+		       sizeof(usb_stor_host_template));
+
+		/* Grab the next host number */
+		ss->host_number = my_host_number++;
+			
+		/* We abuse this pointer so we can pass the ss pointer to 
+		 * the host controler thread in us_detect.  But how else are
+		 * we to do it?
+		 */
+		(struct us_data *)ss->htmplt.proc_dir = ss; 
+		
+		/* start up our control thread */
+		ss->pid = kernel_thread(usb_stor_control_thread, ss,
+					CLONE_FS | CLONE_FILES |
+					CLONE_SIGHAND);
+		if (ss->pid < 0) {
+			printk(KERN_WARNING USB_STORAGE 
+			       "Unable to start control thread\n");
+			kfree(ss->current_urb);
+			kfree(ss);
+			return NULL;
+		}
+		
+		/* wait for the thread to start */
+		down(&(ss->notify));
+			
+		/* now register	 - our detect function will be called */
+		ss->htmplt.module = THIS_MODULE;
+		scsi_register_module(MODULE_SCSI_HA, &(ss->htmplt));
+		
+		/* put us in the list */
+		ss->next = us_list;
+		us_list = ss;
+	}
+
+	/* release the data structure lock */
+	up(&us_list_semaphore);
+
+	printk(KERN_DEBUG 
+	       "WARNING: USB Mass Storage data integrity not assured\n");
+	printk(KERN_DEBUG 
+	       "USB Mass Storage device found at %d\n", dev->devnum);
+
+	/* return a pointer for the disconnect function */
+	return ss;
+}
+
+/* Handle a disconnect event from the USB core */
+static void storage_disconnect(struct usb_device *dev, void *ptr)
+{
+	struct us_data *ss = ptr;
+	int result;
+
+	US_DEBUGP("storage_disconnect() called\n");
+
+	/* this is the odd case -- we disconnected but weren't using it */
+	if (!ss) {
+		US_DEBUGP("-- device was not in use\n");
+		return;
+	}
+
+	/* lock access to the device data structure */
+	down(&(ss->dev_semaphore));
+
+	/* release the IRQ, if we have one */
+	down(&(ss->irq_urb_sem));
+	if (ss->irq_urb) {
+		US_DEBUGP("-- releasing irq handle\n");
+		result = usb_unlink_urb(ss->irq_urb);
+		ss->irq_urb = NULL;
+		US_DEBUGP("-- usb_unlink_urb() returned %d\n", result);
+		usb_free_urb(ss->irq_urb);
+	}
+	up(&(ss->irq_urb_sem));
+
+	/* mark the device as gone */
+	ss->pusb_dev = NULL;
+
+	/* lock access to the device data structure */
+	up(&(ss->dev_semaphore));
+}
+
+/***********************************************************************
+ * Initialization and registration
+ ***********************************************************************/
+
+int __init usb_stor_init(void)
+{
+	/* initialize internal global data elements */
+	us_list = NULL;
+	init_MUTEX(&us_list_semaphore);
+	my_host_number = 0;
+
+	/* register the driver, return -1 if error */
+	if (usb_register(&storage_driver) < 0)
+		return -1;
+
+	/* we're all set */
+	printk(KERN_INFO "USB Mass Storage support registered.\n");
+	return 0;
+}
+
+void __exit usb_stor_exit(void)
+{
+	struct us_data *next;
+	
+	US_DEBUGP("usb_stor_exit() called\n");
+
+	/* Deregister the driver
+	 * This eliminates races with probes and disconnects 
+	 */
+	US_DEBUGP("-- calling usb_deregister()\n");
+	usb_deregister(&storage_driver) ;
+	
+	/* lock access to the data structures */
+	down(&us_list_semaphore);
+
+	/* While there are still virtual hosts, unregister them
+	 *
+	 * Note that the us_release() routine will destroy the local data
+	 * structure.  So we have to peel these off the top of the list
+	 * and keep updating the head pointer as we go.
+	 */
+	while (us_list) {
+		/* keep track of where the next one is */
+		next = us_list->next;
+
+		US_DEBUGP("-- calling scsi_unregister_module()\n");
+		scsi_unregister_module(MODULE_SCSI_HA, &(us_list->htmplt));
+
+                /* Now that scsi_unregister_module is done with the host
+                 * template, we can free the us_data structure (the host
+                 * template is inline in this structure). */
+                kfree (us_list);
+
+		/* advance the list pointer */
+		us_list = next;
+	}
+	
+	/* unlock the data structures */
+	up(&us_list_semaphore);
+}
+
+module_init(usb_stor_init) ;
+module_exit(usb_stor_exit) ;
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)