usb.c

omap3 linux 2.6 用nocc去除了冗余代码

		if (unusual_dev->useTransport != US_PR_DEVICE &&
			us->protocol == idesc->bInterfaceProtocol)
			msg += 2;
		if (msg >= 0 && !(us->flags & US_FL_NEED_OVERRIDE))
			printk(KERN_NOTICE USB_STORAGE "This device "
				"(%04x,%04x,%04x S %02x P %02x)"
				" has %s in unusual_devs.h (kernel"
				" %s)\n"
				"   Please send a copy of this message to "
				"<[e-mail]>\n",
				le16_to_cpu(ddesc->idVendor),
				le16_to_cpu(ddesc->idProduct),
				le16_to_cpu(ddesc->bcdDevice),
				idesc->bInterfaceSubClass,
				idesc->bInterfaceProtocol,
				msgs[msg],
				utsname()->release);
	}

	return 0;
}

/* Get the transport settings */
static int get_transport(struct us_data *us)
{
	switch (us->protocol) {
	case US_PR_CB:
		us->transport_name = "Control/Bulk";
		us->transport = usb_stor_CB_transport;
		us->transport_reset = usb_stor_CB_reset;
		us->max_lun = 7;
		break;

	case US_PR_CBI:
		us->transport_name = "Control/Bulk/Interrupt";
		us->transport = usb_stor_CBI_transport;
		us->transport_reset = usb_stor_CB_reset;
		us->max_lun = 7;
		break;

	case US_PR_BULK:
		us->transport_name = "Bulk";
		us->transport = usb_stor_Bulk_transport;
		us->transport_reset = usb_stor_Bulk_reset;
		break;










	default:
		return -EIO;
	}
	US_DEBUGP("Transport: %s\n", us->transport_name);

	/* fix for single-lun devices */
	if (us->flags & US_FL_SINGLE_LUN)
		us->max_lun = 0;
	return 0;
}

/* Get the protocol settings */
static int get_protocol(struct us_data *us)
{
	switch (us->subclass) {
	case US_SC_RBC:
		us->protocol_name = "Reduced Block Commands (RBC)";
		us->proto_handler = usb_stor_transparent_scsi_command;
		break;

	case US_SC_8020:
		us->protocol_name = "8020i";
		us->proto_handler = usb_stor_ATAPI_command;
		us->max_lun = 0;
		break;

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

	case US_SC_8070:
		us->protocol_name = "8070i";
		us->proto_handler = usb_stor_ATAPI_command;
		us->max_lun = 0;
		break;

	case US_SC_SCSI:
		us->protocol_name = "Transparent SCSI";
		us->proto_handler = usb_stor_transparent_scsi_command;
		break;

	case US_SC_UFI:
		us->protocol_name = "Uniform Floppy Interface (UFI)";
		us->proto_handler = usb_stor_ufi_command;
		break;


	default:
		return -EIO;
	}
	US_DEBUGP("Protocol: %s\n", us->protocol_name);
	return 0;
}

/* Get the pipe settings */
static int get_pipes(struct us_data *us)
{
	struct usb_host_interface *altsetting =
		us->pusb_intf->cur_altsetting;
	int i;
	struct usb_endpoint_descriptor *ep;
	struct usb_endpoint_descriptor *ep_in = NULL;
	struct usb_endpoint_descriptor *ep_out = NULL;
	struct usb_endpoint_descriptor *ep_int = NULL;

	/*
	 * Find the first endpoint of each type we need.
	 * We are expecting a minimum of 2 endpoints - in and out (bulk).
	 * An optional interrupt-in is OK (necessary for CBI protocol).
	 * We will ignore any others.
	 */
	for (i = 0; i < altsetting->desc.bNumEndpoints; i++) {
		ep = &altsetting->endpoint[i].desc;

		if (usb_endpoint_xfer_bulk(ep)) {
			if (usb_endpoint_dir_in(ep)) {
				if (!ep_in)
					ep_in = ep;
			} else {
				if (!ep_out)
					ep_out = ep;
			}
		}

		else if (usb_endpoint_is_int_in(ep)) {
			if (!ep_int)
				ep_int = ep;
		}
	}

	if (!ep_in || !ep_out || (us->protocol == US_PR_CBI && !ep_int)) {
		US_DEBUGP("Endpoint sanity check failed! Rejecting dev.\n");
		return -EIO;
	}

	/* Calculate and store the pipe values */
	us->send_ctrl_pipe = usb_sndctrlpipe(us->pusb_dev, 0);
	us->recv_ctrl_pipe = usb_rcvctrlpipe(us->pusb_dev, 0);
	us->send_bulk_pipe = usb_sndbulkpipe(us->pusb_dev,
		ep_out->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
	us->recv_bulk_pipe = usb_rcvbulkpipe(us->pusb_dev, 
		ep_in->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
	if (ep_int) {
		us->recv_intr_pipe = usb_rcvintpipe(us->pusb_dev,
			ep_int->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
		us->ep_bInterval = ep_int->bInterval;
	}
	return 0;
}

/* Initialize all the dynamic resources we need */
static int usb_stor_acquire_resources(struct us_data *us)
{
	int p;
	struct task_struct *th;

	us->current_urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!us->current_urb) {
		US_DEBUGP("URB allocation failed\n");
		return -ENOMEM;
	}

	/* Just before we start our control thread, initialize
	 * the device if it needs initialization */
	if (us->unusual_dev->initFunction) {
		p = us->unusual_dev->initFunction(us);
		if (p)
			return p;
	}

	/* Start up our control thread */
	th = kthread_create(usb_stor_control_thread, us, "usb-storage");
	if (IS_ERR(th)) {
		printk(KERN_WARNING USB_STORAGE 
		       "Unable to start control thread\n");
		return PTR_ERR(th);
	}

	/* Take a reference to the host for the control thread and
	 * count it among all the threads we have launched.  Then
	 * start it up. */
	scsi_host_get(us_to_host(us));
	atomic_inc(&total_threads);
	wake_up_process(th);

	return 0;
}

/* Release all our dynamic resources */
static void usb_stor_release_resources(struct us_data *us)
{
	US_DEBUGP("-- %s\n", __FUNCTION__);

	/* Tell the control thread to exit.  The SCSI host must
	 * already have been removed so it won't try to queue
	 * any more commands.
	 */
	US_DEBUGP("-- sending exit command to thread\n");
	set_bit(US_FLIDX_DISCONNECTING, &us->flags);
	up(&us->sema);

	/* Call the destructor routine, if it exists */
	if (us->extra_destructor) {
		US_DEBUGP("-- calling extra_destructor()\n");
		us->extra_destructor(us->extra);
	}

	/* Free the extra data and the URB */
	kfree(us->extra);
	usb_free_urb(us->current_urb);
}

/* Dissociate from the USB device */
static void dissociate_dev(struct us_data *us)
{
	US_DEBUGP("-- %s\n", __FUNCTION__);

	kfree(us->sensebuf);

	/* Free the device-related DMA-mapped buffers */
	if (us->cr)
		usb_buffer_free(us->pusb_dev, sizeof(*us->cr), us->cr,
				us->cr_dma);
	if (us->iobuf)
		usb_buffer_free(us->pusb_dev, US_IOBUF_SIZE, us->iobuf,
				us->iobuf_dma);

	/* Remove our private data from the interface */
	usb_set_intfdata(us->pusb_intf, NULL);
}

/* First stage of disconnect processing: stop all commands and remove
 * the host */
static void quiesce_and_remove_host(struct us_data *us)
{
	struct Scsi_Host *host = us_to_host(us);

	/* Prevent new USB transfers, stop the current command, and
	 * interrupt a SCSI-scan or device-reset delay */
	scsi_lock(host);
	set_bit(US_FLIDX_DISCONNECTING, &us->flags);
	scsi_unlock(host);
	usb_stor_stop_transport(us);
	wake_up(&us->delay_wait);

	/* It doesn't matter if the SCSI-scanning thread is still running.
	 * The thread will exit when it sees the DISCONNECTING flag. */

	/* queuecommand won't accept any new commands and the control
	 * thread won't execute a previously-queued command.  If there
	 * is such a command pending, complete it with an error. */
	mutex_lock(&us->dev_mutex);
	if (us->srb) {
		us->srb->result = DID_NO_CONNECT << 16;
		scsi_lock(host);
		us->srb->scsi_done(us->srb);
		us->srb = NULL;
		scsi_unlock(host);
	}
	mutex_unlock(&us->dev_mutex);

	/* Now we own no commands so it's safe to remove the SCSI host */
	scsi_remove_host(host);
}

/* Second stage of disconnect processing: deallocate all resources */
static void release_everything(struct us_data *us)
{
	usb_stor_release_resources(us);
	dissociate_dev(us);

	/* Drop our reference to the host; the SCSI core will free it
	 * (and "us" along with it) when the refcount becomes 0. */
	scsi_host_put(us_to_host(us));
}

/* Thread to carry out delayed SCSI-device scanning */
static int usb_stor_scan_thread(void * __us)
{
	struct us_data *us = (struct us_data *)__us;

	printk(KERN_DEBUG
		"usb-storage: device found at %d\n", us->pusb_dev->devnum);

	/* Wait for the timeout to expire or for a disconnect */
	if (delay_use > 0) {
		printk(KERN_DEBUG "usb-storage: waiting for device "
				"to settle before scanning\n");
retry:
		wait_event_interruptible_timeout(us->delay_wait,
				test_bit(US_FLIDX_DISCONNECTING, &us->flags),
				delay_use * HZ);
		if (try_to_freeze())
			goto retry;
	}

	/* If the device is still connected, perform the scanning */
	if (!test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {

		/* For bulk-only devices, determine the max LUN value */
		if (us->protocol == US_PR_BULK &&
				!(us->flags & US_FL_SINGLE_LUN)) {
			mutex_lock(&us->dev_mutex);
			us->max_lun = usb_stor_Bulk_max_lun(us);
			mutex_unlock(&us->dev_mutex);
		}
		scsi_scan_host(us_to_host(us));
		printk(KERN_DEBUG "usb-storage: device scan complete\n");

		/* Should we unbind if no devices were detected? */
	}

	scsi_host_put(us_to_host(us));
	complete_and_exit(&threads_gone, 0);
}


/* Probe to see if we can drive a newly-connected USB device */
static int storage_probe(struct usb_interface *intf,
			 const struct usb_device_id *id)
{
	struct Scsi_Host *host;
	struct us_data *us;
	int result;
	struct task_struct *th;

	if (usb_usual_check_type(id, USB_US_TYPE_STOR))
		return -ENXIO;

	US_DEBUGP("USB Mass Storage device detected\n");

	/*
	 * Ask the SCSI layer to allocate a host structure, with extra
	 * space at the end for our private us_data structure.
	 */
	host = scsi_host_alloc(&usb_stor_host_template, sizeof(*us));
	if (!host) {
		printk(KERN_WARNING USB_STORAGE
			"Unable to allocate the scsi host\n");
		return -ENOMEM;
	}

	us = host_to_us(host);
	memset(us, 0, sizeof(struct us_data));
	mutex_init(&(us->dev_mutex));
	init_MUTEX_LOCKED(&(us->sema));
	init_completion(&(us->notify));
	init_waitqueue_head(&us->delay_wait);

	/* Associate the us_data structure with the USB device */
	result = associate_dev(us, intf);
	if (result)
		goto BadDevice;

	/*
	 * Get the unusual_devs entries and the descriptors
	 *
	 * id_index is calculated in the declaration to be the index number
	 * of the match from the usb_device_id table, so we can find the
	 * corresponding entry in the private table.
	 */
	result = get_device_info(us, id);
	if (result)
		goto BadDevice;

	/* Get the transport, protocol, and pipe settings */
	result = get_transport(us);
	if (result)
		goto BadDevice;
	result = get_protocol(us);
	if (result)
		goto BadDevice;
	result = get_pipes(us);
	if (result)
		goto BadDevice;

	/* Acquire all the other resources and add the host */
	result = usb_stor_acquire_resources(us);
	if (result)
		goto BadDevice;
	result = scsi_add_host(host, &intf->dev);
	if (result) {
		printk(KERN_WARNING USB_STORAGE
			"Unable to add the scsi host\n");
		goto BadDevice;
	}

	/* Start up the thread for delayed SCSI-device scanning */
	th = kthread_create(usb_stor_scan_thread, us, "usb-stor-scan");
	if (IS_ERR(th)) {
		printk(KERN_WARNING USB_STORAGE 
		       "Unable to start the device-scanning thread\n");
		quiesce_and_remove_host(us);
		result = PTR_ERR(th);
		goto BadDevice;
	}

	/* Take a reference to the host for the scanning thread and
	 * count it among all the threads we have launched.  Then
	 * start it up. */
	scsi_host_get(us_to_host(us));
	atomic_inc(&total_threads);
	wake_up_process(th);

	return 0;

	/* We come here if there are any problems */
BadDevice:
	US_DEBUGP("storage_probe() failed\n");
	release_everything(us);
	return result;
}

/* Handle a disconnect event from the USB core */
static void storage_disconnect(struct usb_interface *intf)
{
	struct us_data *us = usb_get_intfdata(intf);

	US_DEBUGP("storage_disconnect() called\n");
	quiesce_and_remove_host(us);
	release_everything(us);
}

/***********************************************************************
 * Initialization and registration
 ***********************************************************************/

static struct usb_driver usb_storage_driver = {
	.name =		"usb-storage",
	.probe =	storage_probe,
	.disconnect =	storage_disconnect,
	.suspend =	storage_suspend,
	.resume =	storage_resume,
	.pre_reset =	storage_pre_reset,
	.post_reset =	storage_post_reset,
	.id_table =	storage_usb_ids,
};

static int __init usb_stor_init(void)
{
	int retval;
	printk(KERN_INFO "Initializing USB Mass Storage driver...\n");

	/* register the driver, return usb_register return code if error */
	retval = usb_register(&usb_storage_driver);
	if (retval == 0) {
		printk(KERN_INFO "USB Mass Storage support registered.\n");
		usb_usual_set_present(USB_US_TYPE_STOR);
	}
	return retval;
}

static void __exit usb_stor_exit(void)
{
	US_DEBUGP("usb_stor_exit() called\n");

	/* Deregister the driver
	 * This will cause disconnect() to be called for each
	 * attached unit
	 */
	US_DEBUGP("-- calling usb_deregister()\n");
	usb_deregister(&usb_storage_driver) ;

	/* Don't return until all of our control and scanning threads
	 * have exited.  Since each thread signals threads_gone as its
	 * last act, we have to call wait_for_completion the right number
	 * of times.
	 */
	while (atomic_read(&total_threads) > 0) {
		wait_for_completion(&threads_gone);
		atomic_dec(&total_threads);
	}

	usb_usual_clear_present(USB_US_TYPE_STOR);
}

module_init(usb_stor_init);
module_exit(usb_stor_exit);