usb.c

讲述linux的初始化过程

		"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);