- Kai Germaschewski: ISDN update (including Makefiles)

[davej-history.git] / drivers / usb / storage / usb.c

/* Driver for USB Mass Storage compliant devices
 *
 * $Id: usb.c,v 1.57 2000/11/21 02:56:41 mdharm Exp $
 *
 * Current development and maintenance 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 <linux/config.h>
#include "usb.h"
#include "scsiglue.h"
#include "transport.h"
#include "protocol.h"
#include "debug.h"
#include "initializers.h"
#ifdef CONFIG_USB_STORAGE_HP8200e
#include "shuttle_usbat.h"
#endif
#ifdef CONFIG_USB_STORAGE_SDDR09
#include "sddr09.h"
#endif
#ifdef CONFIG_USB_STORAGE_DPCM
#include "dpcm.h"
#endif
#ifdef CONFIG_USB_STORAGE_FREECOM
#include "freecom.h"
#endif

#include <linux/module.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/malloc.h>

/* Some informational data */
MODULE_AUTHOR("Matthew Dharm <mdharm-usb@one-eyed-alien.net>");
MODULE_DESCRIPTION("USB Mass Storage driver for Linux");

/*
 * 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,
                            const struct usb_device_id *id);
static void storage_disconnect(struct usb_device *dev, void *ptr);
struct usb_driver usb_storage_driver = {
        name:           "usb-storage",
        probe:          storage_probe,
        disconnect:     storage_disconnect,
};

/*
 * fill_inquiry_response takes an unsigned char array (which must
 * be at least 36 characters) and populates the vendor name,
 * product name, and revision fields. Then the array is copied
 * into the SCSI command's response buffer (oddly enough
 * called request_buffer). data_len contains the length of the
 * data array, which again must be at least 36.
 */

void fill_inquiry_response(struct us_data *us, unsigned char *data,
                unsigned int data_len) {

        int i;
        struct scatterlist *sg;
        int len =
                us->srb->request_bufflen > data_len ? data_len :
                us->srb->request_bufflen;
        int transferred;
        int amt;

        if (data_len<36) // You lose.
                return;

        memcpy(data+8, us->unusual_dev->vendorName, 
                strlen(us->unusual_dev->vendorName) > 8 ? 8 :
                strlen(us->unusual_dev->vendorName));
        memcpy(data+16, us->unusual_dev->productName, 
                strlen(us->unusual_dev->productName) > 16 ? 16 :
                strlen(us->unusual_dev->productName));
        data[32] = 0x30 + ((us->pusb_dev->descriptor.bcdDevice>>12) & 0x0F);
        data[33] = 0x30 + ((us->pusb_dev->descriptor.bcdDevice>>8) & 0x0F);
        data[34] = 0x30 + ((us->pusb_dev->descriptor.bcdDevice>>4) & 0x0F);
        data[35] = 0x30 + ((us->pusb_dev->descriptor.bcdDevice) & 0x0F);

        if (us->srb->use_sg) {
                sg = (struct scatterlist *)us->srb->request_buffer;
                for (i=0; i<us->srb->use_sg; i++)
                        memset(sg[i].address, 0, sg[i].length);
                for (i=0, transferred=0; 
                                i<us->srb->use_sg && transferred < len;
                                i++) {
                        amt = sg[i].length > len-transferred ? 
                                        len-transferred : sg[i].length;
                        memcpy(sg[i].address, data+transferred, amt);
                        transferred -= amt;
                }
        } else {
                memset(us->srb->request_buffer, 0, us->srb->request_bufflen);
                memcpy(us->srb->request_buffer, data, len);
        }
}

static int usb_stor_control_thread(void * __us)
{
        wait_queue_t wait;
        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..
         */
        exit_files(current);
        current->files = init_task.files;
        atomic_inc(&current->files->count);
        daemonize();

        /* set our name for identification purposes */
        sprintf(current->comm, "usb-storage-%d", us->host_number);

        unlock_kernel();

        /* set up for wakeups by new commands */
        init_waitqueue_entry(&wait, current);
        init_waitqueue_head(&(us->wqh));
        add_wait_queue(&(us->wqh), &wait);

        /* signal that we've started the thread */
        up(&(us->notify));
        set_current_state(TASK_INTERRUPTIBLE);

        for(;;) {
                US_DEBUGP("*** thread sleeping.\n");
                schedule();
                US_DEBUGP("*** thread awakened.\n");

                /* lock access to the queue element */
                down(&(us->queue_exclusion));

                /* 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 the command if the direction indicator 
                         * is UNKNOWN
                         */
                        if (us->srb->sc_data_direction == SCSI_DATA_UNKNOWN) {
                                US_DEBUGP("UNKNOWN data direction\n");
                                us->srb->result = DID_ERROR << 16;
                                set_current_state(TASK_INTERRUPTIBLE);
                                us->srb->scsi_done(us->srb);
                                us->srb = NULL;
                                break;
                        }

                        /* reject if target != 0 or if LUN is higher than
                         * the maximum known LUN
                         */
                        if (us->srb->target && 
                                        !(us->flags & US_FL_SCM_MULT_TARG)) {
                                US_DEBUGP("Bad target number (%d/%d)\n",
                                          us->srb->target, us->srb->lun);
                                us->srb->result = DID_BAD_TARGET << 16;

                                set_current_state(TASK_INTERRUPTIBLE);
                                us->srb->scsi_done(us->srb);
                                us->srb = NULL;
                                break;
                        }

                        if (us->srb->lun > us->max_lun) {
                                US_DEBUGP("Bad LUN (%d/%d)\n",
                                          us->srb->target, us->srb->lun);
                                us->srb->result = DID_BAD_TARGET << 16;

                                set_current_state(TASK_INTERRUPTIBLE);
                                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_DEBUGP("Skipping START_STOP command\n");
                                us->srb->result = GOOD << 1;

                                set_current_state(TASK_INTERRUPTIBLE);
                                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 << 1;
                                } else {
                                        memcpy(us->srb->sense_buffer, 
                                               usb_stor_sense_notready, 
                                               sizeof(usb_stor_sense_notready));
                                        us->srb->result = CHECK_CONDITION << 1;
                                }
                        } 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);
                                set_current_state(TASK_INTERRUPTIBLE);
                                us->srb->scsi_done(us->srb);
                        } else {
                                US_DEBUGP("scsi command aborted\n");
                                set_current_state(TASK_INTERRUPTIBLE);
                                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 (;;) */

        /* clean up after ourselves */
        set_current_state(TASK_INTERRUPTIBLE);
        remove_wait_queue(&(us->wqh), &wait);

        /* 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 */

/* The vendor name should be kept at eight characters or less, and
 * the product name should be kept at 16 characters or less. If a device
 * has the US_FL_DUMMY_INQUIRY flag, then the vendor and product names
 * normally generated by a device thorugh the INQUIRY response will be
 * taken from this list, and this is the reason for the above size
 * restriction. However, if the flag is not present, then you
 * are free to use as many characters as you like.
 */
static struct us_unusual_dev us_unusual_dev_list[] = {

        { 0x03ee, 0x0000, 0x0000, 0x0245, 
                "Mitsumi",
                "CD-R/RW Drive",
                US_SC_8020, US_PR_CBI, NULL, 0}, 

        { 0x03f0, 0x0107, 0x0200, 0x0200, 
                "HP",
                "CD-Writer+",
                US_SC_8070, US_PR_CB, NULL, 0}, 

#ifdef CONFIG_USB_STORAGE_HP8200e
        { 0x03f0, 0x0207, 0x0001, 0x0001, 
                "HP",
                "CD-Writer+ 8200e",
                US_SC_8070, US_PR_SCM_ATAPI, init_8200e, 0}, 
#endif

        { 0x04e6, 0x0001, 0x0200, 0x0200, 
                "Matshita",
                "LS-120",
                US_SC_8020, US_PR_CB, NULL, 0},

        { 0x04e6, 0x0002, 0x0100, 0x0100, 
                "Shuttle",
                "eUSCSI Bridge",
                US_SC_SCSI, US_PR_BULK, usb_stor_euscsi_init, 
                US_FL_SCM_MULT_TARG }, 

#ifdef CONFIG_USB_STORAGE_SDDR09
        { 0x04e6, 0x0003, 0x0000, 0x9999, 
                "Sandisk",
                "ImageMate SDDR09",
                US_SC_SCSI, US_PR_EUSB_SDDR09, NULL,
                US_FL_SINGLE_LUN | US_FL_START_STOP },
#endif

#ifdef CONFIG_USB_STORAGE_DPCM
        { 0x0436, 0x0005, 0x0100, 0x0100,
                "Microtech",
                "CameraMate (DPCM_USB)",
                US_SC_SCSI, US_PR_DPCM_USB, NULL,
                US_FL_START_STOP },
#endif

        { 0x04e6, 0x0006, 0x0100, 0x0200, 
                "Shuttle",
                "eUSB MMC Adapter",
                US_SC_SCSI, US_PR_CB, NULL, 
                US_FL_SINGLE_LUN}, 

        { 0x04e6, 0x0007, 0x0100, 0x0200, 
                "Sony",
                "Hifd",
                US_SC_SCSI, US_PR_CB, NULL, 
                US_FL_SINGLE_LUN}, 

        { 0x04e6, 0x0009, 0x0200, 0x0200, 
                "Shuttle",
                "eUSB ATA/ATAPI Adapter",
                US_SC_8020, US_PR_CB, NULL, 0},

        { 0x04e6, 0x000a, 0x0200, 0x0200, 
                "Shuttle",
                "eUSB CompactFlash Adapter",
                US_SC_8020, US_PR_CB, NULL, 0},

        { 0x04e6, 0x000B, 0x0100, 0x0100, 
                "Shuttle",
                "eUSCSI Bridge",
                US_SC_SCSI, US_PR_BULK, usb_stor_euscsi_init, 
                US_FL_SCM_MULT_TARG }, 

        { 0x04e6, 0x000C, 0x0100, 0x0100, 
                "Shuttle",
                "eUSCSI Bridge",
                US_SC_SCSI, US_PR_BULK, usb_stor_euscsi_init, 
                US_FL_SCM_MULT_TARG }, 

        { 0x04e6, 0x0101, 0x0200, 0x0200, 
                "Shuttle",
                "CD-RW Device",
                US_SC_8020, US_PR_CB, NULL, 0},

        { 0x054c, 0x0010, 0x0106, 0x0210, 
                "Sony",
                "DSC-S30/S70/505V/F505", 
                US_SC_SCSI, US_PR_CB, NULL,
                US_FL_SINGLE_LUN | US_FL_START_STOP | US_FL_MODE_XLATE },

        { 0x054c, 0x002d, 0x0100, 0x0100, 
                "Sony",
                "Memorystick MSAC-US1",
                US_SC_UFI, US_PR_CB, NULL,
                US_FL_SINGLE_LUN | US_FL_START_STOP },

        { 0x057b, 0x0000, 0x0000, 0x0299, 
                "Y-E Data",
                "Flashbuster-U",
                US_SC_UFI,  US_PR_CB, NULL,
                US_FL_SINGLE_LUN},

        { 0x057b, 0x0000, 0x0300, 0x9999, 
                "Y-E Data",
                "Flashbuster-U",
                US_SC_UFI,  US_PR_CBI, NULL,
                US_FL_SINGLE_LUN},

        { 0x059f, 0xa601, 0x0200, 0x0200, 
                "LaCie",
                "USB Hard Disk",
                US_SC_RBC, US_PR_CB, NULL, 0 }, 

        { 0x05ab, 0x0031, 0x0100, 0x0100, 
                "In-System",
                "USB/IDE Bridge (ATAPI ONLY!)",
                US_SC_8070, US_PR_BULK, NULL, 0 }, 

        { 0x0644, 0x0000, 0x0100, 0x0100, 
                "TEAC",
                "Floppy Drive",
                US_SC_UFI, US_PR_CB, NULL, 0 }, 

#ifdef CONFIG_USB_STORAGE_SDDR09
        { 0x066b, 0x0105, 0x0100, 0x0100, 
                "Olympus",
                "Camedia MAUSB-2",
                US_SC_SCSI, US_PR_EUSB_SDDR09, NULL,
                US_FL_SINGLE_LUN | US_FL_START_STOP },
#endif

        { 0x0693, 0x0002, 0x0100, 0x0100, 
                "Hagiwara",
                "FlashGate SmartMedia",
                US_SC_SCSI, US_PR_BULK, NULL, 0 },

        { 0x0693, 0x0005, 0x0100, 0x0100,
                "Hagiwara",
                "Flashgate",
                US_SC_SCSI, US_PR_BULK, NULL, 0 }, 

        { 0x0781, 0x0001, 0x0200, 0x0200, 
                "Sandisk",
                "ImageMate SDDR-05a",
                US_SC_SCSI, US_PR_CB, NULL,
                US_FL_SINGLE_LUN | US_FL_START_STOP},

        { 0x0781, 0x0100, 0x0100, 0x0100,
                "Sandisk",
                "ImageMate SDDR-12",
                US_SC_SCSI, US_PR_CB, NULL,
                US_FL_SINGLE_LUN },

#ifdef CONFIG_USB_STORAGE_SDDR09
        { 0x0781, 0x0200, 0x0100, 0x0208, 
                "Sandisk",
                "ImageMate SDDR-09",
                US_SC_SCSI, US_PR_EUSB_SDDR09, NULL,
                US_FL_SINGLE_LUN | US_FL_START_STOP },
#endif

        { 0x0781, 0x0002, 0x0009, 0x0009, 
                "Sandisk",
                "ImageMate SDDR-31",
                US_SC_SCSI, US_PR_BULK, NULL,
                US_FL_IGNORE_SER},

        { 0x07af, 0x0004, 0x0100, 0x0100, 
                "Microtech",
                "USB-SCSI-DB25",
                US_SC_SCSI, US_PR_BULK, usb_stor_euscsi_init,
                US_FL_SCM_MULT_TARG }, 

#ifdef CONFIG_USB_STORAGE_FREECOM
        { 0x07ab, 0xfc01, 0x0000, 0x9999,
                "Freecom",
                "USB-IDE",
                US_SC_QIC, US_PR_FREECOM, freecom_init, 0},
#endif

        { 0x07af, 0x0005, 0x0100, 0x0100, 
                "Microtech",
                "USB-SCSI-HD50",
                US_SC_SCSI, US_PR_BULK, usb_stor_euscsi_init,
                US_FL_SCM_MULT_TARG }, 

#ifdef CONFIG_USB_STORAGE_DPCM
        { 0x07af, 0x0006, 0x0100, 0x0100,
                "Microtech",
                "CameraMate (DPCM_USB)",
                US_SC_SCSI, US_PR_DPCM_USB, NULL,
                US_FL_START_STOP },
#endif
        { 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 %s\n", ptr->vendorName,
                ptr->productName);
        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,
                            const struct usb_device_id *id)
{
        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;
#ifdef CONFIG_USB_STORAGE_SDDR09
        int result;
#endif

        /* 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);

#ifdef CONFIG_USB_STORAGE_SDDR09
        if (protocol == US_PR_EUSB_SDDR09 || protocol == US_PR_DPCM_USB) {
                /* set the configuration -- STALL is an acceptable response here */
                result = usb_set_configuration(dev, 1);

                US_DEBUGP("Result from usb_set_configuration 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;
                }
        }
#endif

        /* 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 */
        usb_inc_dev_use(dev);

        /* 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");
        }

        /*
         * Now check if we have seen this GUID before
         * We're looking for a device with a matching GUID that isn't
         * already 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));

                /* lock the device pointers */
                down(&(ss->dev_semaphore));

                /* 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)) {
                        usb_dec_dev_use(dev);
                        return NULL;
                }

                /* allocate the URB we're going to use */
                ss->current_urb = usb_alloc_urb(0);
                if (!ss->current_urb) {
                        usb_dec_dev_use(dev);
                        return NULL;
                }

                /* Re-Initialize the device if it needs it */
                if (unusual_dev && unusual_dev->initFunction)
                        (unusual_dev->initFunction)(ss);

                /* unlock the device pointers */
                up(&(ss->dev_semaphore));

        } 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");
                        usb_dec_dev_use(dev);
                        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);
                        usb_dec_dev_use(dev);
                        return NULL;
                }

                /* Initialize the mutexes only when the struct is new */
                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;
                ss->unusual_dev = unusual_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;

                /* 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) {
                        if (unusual_dev)
                                strncpy(ss->vendor, unusual_dev->vendorName,
                                        USB_STOR_STRING_LEN);
                        else
                                strncpy(ss->vendor, "Unknown",
                                        USB_STOR_STRING_LEN);
                }
                if (strlen(ss->product) == 0) {
                        if (unusual_dev)
                                strncpy(ss->product, unusual_dev->productName,
                                        USB_STOR_STRING_LEN);
                        else
                                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;

#ifdef CONFIG_USB_STORAGE_HP8200e
                case US_PR_SCM_ATAPI:
                        ss->transport_name = "SCM/ATAPI";
                        ss->transport = hp8200e_transport;
                        ss->transport_reset = usb_stor_CB_reset;
                        ss->max_lun = 1;
                        break;
#endif

#ifdef CONFIG_USB_STORAGE_SDDR09
                case US_PR_EUSB_SDDR09:
                        ss->transport_name = "EUSB/SDDR09";
                        ss->transport = sddr09_transport;
                        ss->transport_reset = usb_stor_CB_reset;
                        ss->max_lun = 0;
                        break;
#endif

#ifdef CONFIG_USB_STORAGE_DPCM
                case US_PR_DPCM_USB:
                        ss->transport_name = "Control/Bulk-EUSB/SDDR09";
                        ss->transport = dpcm_transport;
                        ss->transport_reset = usb_stor_CB_reset;
                        ss->max_lun = 1;
                        break;
#endif

#ifdef CONFIG_USB_STORAGE_FREECOM
                case US_PR_FREECOM:
                        ss->transport_name = "Freecom";
                        ss->transport = freecom_transport;
                        ss->transport_reset = usb_stor_freecom_reset;
                        ss->max_lun = 0;
                        break;
#endif

                default:
                        ss->transport_name = "Unknown";
                        kfree(ss->current_urb);
                        kfree(ss);
                        usb_dec_dev_use(dev);
                        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;
                        ss->max_lun = 0;
                        break;

                case US_SC_QIC:
                        ss->protocol_name = "QIC-157";
                        ss->proto_handler = usb_stor_qic157_command;
                        ss->max_lun = 0;
                        break;

                case US_SC_8070:
                        ss->protocol_name = "8070i";
                        ss->proto_handler = usb_stor_ATAPI_command;
                        ss->max_lun = 0;
                        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";
                        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)) {
                        usb_dec_dev_use(dev);
                        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; 

                /* Just before we start our control thread, initialize
                 * the device if it needs initialization */
                if (unusual_dev && unusual_dev->initFunction)
                        unusual_dev->initFunction(ss);

                /* start up our control thread */
                ss->pid = kernel_thread(usb_stor_control_thread, ss,
                                        CLONE_VM);
                if (ss->pid < 0) {
                        printk(KERN_WARNING USB_STORAGE 
                               "Unable to start control thread\n");
                        kfree(ss->current_urb);
                        kfree(ss);
                        usb_dec_dev_use(dev);
                        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));

                /* lock access to the data structures */
                down(&us_list_semaphore);

                /* 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 URB\n");
                result = usb_unlink_urb(ss->irq_urb);
                US_DEBUGP("-- usb_unlink_urb() returned %d\n", result);
                usb_free_urb(ss->irq_urb);
                ss->irq_urb = NULL;
        }
        up(&(ss->irq_urb_sem));

        /* free up the main URB for this device */
        US_DEBUGP("-- releasing main URB\n");
        result = usb_unlink_urb(ss->current_urb);
        US_DEBUGP("-- usb_unlink_urb() returned %d\n", result);
        usb_free_urb(ss->current_urb);
        ss->current_urb = NULL;

        /* mark the device as gone */
        usb_dec_dev_use(ss->pusb_dev);
        ss->pusb_dev = NULL;

        /* unlock 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(&usb_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(&usb_storage_driver) ;

        /* While there are still virtual hosts, unregister them
         * Note that it's important to do this completely before removing
         * the structures because of possible races with the /proc
         * interface
         */
        for (next = us_list; next; next = next->next) {
                US_DEBUGP("-- calling scsi_unregister_module()\n");
                scsi_unregister_module(MODULE_SCSI_HA, &(next->htmplt));
        }

        /* While there are still structures, free them.  Note that we are
         * now race-free, since these structures can no longer be accessed
         * from either the SCSI command layer or the /proc interface
         */
        while (us_list) {
                /* keep track of where the next one is */
                next = us_list->next;

                /* If there's extra data in the us_data structure then
                 * free that first */
                if (us_list->extra) {
                        /* call the destructor routine, if it exists */
                        if (us_list->extra_destructor) {
                                US_DEBUGP("-- calling extra_destructor()\n");
                                us_list->extra_destructor(us_list->extra);
                        }

                        /* destroy the extra data */
                        US_DEBUGP("-- freeing the data structure\n");
                        kfree(us_list->extra);
                }

                /* free the structure itself */
                kfree (us_list);

                /* advance the list pointer */
                us_list = next;
        }
}

module_init(usb_stor_init);
module_exit(usb_stor_exit);