legousbtower.c

优龙2410linux2.6.8内核源代码

	return mask;
}


/**
 *	tower_llseek
 */
static loff_t tower_llseek (struct file *file, loff_t off, int whence)
{
	return -ESPIPE;		/* unseekable */
}


/**
 *	tower_read
 */
static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
{
	struct lego_usb_tower *dev;
	size_t bytes_to_read;
	int i;
	int retval = 0;
	unsigned long timeout = 0;

	dbg(2, "%s: enter, count = %Zd", __FUNCTION__, count);

	dev = (struct lego_usb_tower *)file->private_data;

	/* lock this object */
	if (down_interruptible (&dev->sem)) {
		retval = -ERESTARTSYS;
		goto exit;
	}

	/* verify that the device wasn't unplugged */
	if (dev->udev == NULL) {
		retval = -ENODEV;
		err("No device or device unplugged %d", retval);
		goto unlock_exit;
	}

	/* verify that we actually have some data to read */
	if (count == 0) {
		dbg(1, "%s: read request of 0 bytes", __FUNCTION__);
		goto unlock_exit;
	}

	if (read_timeout) {
		timeout = jiffies + read_timeout * HZ / 1000;
	}

	/* wait for data */
	tower_check_for_read_packet (dev);
	while (dev->read_packet_length == 0) {
		if (file->f_flags & O_NONBLOCK) {
			retval = -EAGAIN;
			goto unlock_exit;
		}
		retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies);
		if (retval < 0) {
			goto unlock_exit;
		}

		/* reset read timeout during read or write activity */
		if (read_timeout
		    && (dev->read_buffer_length || dev->interrupt_out_busy)) {
			timeout = jiffies + read_timeout * HZ / 1000;
		}
		/* check for read timeout */
		if (read_timeout && time_after (jiffies, timeout)) {
			retval = -ETIMEDOUT;
			goto unlock_exit;
		}
		tower_check_for_read_packet (dev);
	}

	/* copy the data from read_buffer into userspace */
	bytes_to_read = min(count, dev->read_packet_length);

	if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) {
		retval = -EFAULT;
		goto unlock_exit;
	}

	spin_lock_irq (&dev->read_buffer_lock);
	dev->read_buffer_length -= bytes_to_read;
	dev->read_packet_length -= bytes_to_read;
	for (i=0; i<dev->read_buffer_length; i++) {
		dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read];
	}
	spin_unlock_irq (&dev->read_buffer_lock);

	retval = bytes_to_read;

unlock_exit:
	/* unlock the device */
	up (&dev->sem);

exit:
	dbg(2, "%s: leave, return value %d", __FUNCTION__, retval);
	return retval;
}


/**
 *	tower_write
 */
static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
{
	struct lego_usb_tower *dev;
	size_t bytes_to_write;
	int retval = 0;

	dbg(2, "%s: enter, count = %Zd", __FUNCTION__, count);

	dev = (struct lego_usb_tower *)file->private_data;

	/* lock this object */
	if (down_interruptible (&dev->sem)) {
		retval = -ERESTARTSYS;
		goto exit;
	}

	/* verify that the device wasn't unplugged */
	if (dev->udev == NULL) {
		retval = -ENODEV;
		err("No device or device unplugged %d", retval);
		goto unlock_exit;
	}

	/* verify that we actually have some data to write */
	if (count == 0) {
		dbg(1, "%s: write request of 0 bytes", __FUNCTION__);
		goto unlock_exit;
	}

	/* wait until previous transfer is finished */
	while (dev->interrupt_out_busy) {
		if (file->f_flags & O_NONBLOCK) {
			retval = -EAGAIN;
			goto unlock_exit;
		}
		retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy);
		if (retval) {
			goto unlock_exit;
		}
	}

	/* write the data into interrupt_out_buffer from userspace */
	bytes_to_write = min(count, write_buffer_size);
	dbg(4, "%s: count = %Zd, bytes_to_write = %Zd", __FUNCTION__, count, bytes_to_write);

	if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) {
		retval = -EFAULT;
		goto unlock_exit;
	}

	/* send off the urb */
	usb_fill_int_urb(dev->interrupt_out_urb,
			 dev->udev,
			 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
			 dev->interrupt_out_buffer,
			 bytes_to_write,
			 tower_interrupt_out_callback,
			 dev,
			 dev->interrupt_out_interval);

	dev->interrupt_out_busy = 1;
	wmb();

	retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL);
	if (retval) {
		dev->interrupt_out_busy = 0;
		err("Couldn't submit interrupt_out_urb %d", retval);
		goto unlock_exit;
	}
	retval = bytes_to_write;

unlock_exit:
	/* unlock the device */
	up (&dev->sem);

exit:
	dbg(2, "%s: leave, return value %d", __FUNCTION__, retval);

	return retval;
}


/**
 *	tower_interrupt_in_callback
 */
static void tower_interrupt_in_callback (struct urb *urb, struct pt_regs *regs)
{
	struct lego_usb_tower *dev = (struct lego_usb_tower *)urb->context;
	int retval;

	dbg(4, "%s: enter, status %d", __FUNCTION__, urb->status);

	lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer);

	if (urb->status) {
		if (urb->status == -ENOENT ||
		    urb->status == -ECONNRESET ||
		    urb->status == -ESHUTDOWN) {
			goto exit;
		} else {
			dbg(1, "%s: nonzero status received: %d", __FUNCTION__, urb->status);
			goto resubmit; /* maybe we can recover */
		}
	}

	if (urb->actual_length > 0) {
		spin_lock (&dev->read_buffer_lock);
		if (dev->read_buffer_length + urb->actual_length < read_buffer_size) {
			memcpy (dev->read_buffer + dev->read_buffer_length,
				dev->interrupt_in_buffer,
				urb->actual_length);
			dev->read_buffer_length += urb->actual_length;
			dev->read_last_arrival = jiffies;
			dbg(3, "%s: received %d bytes", __FUNCTION__, urb->actual_length);
		} else {
			printk(KERN_WARNING "%s: read_buffer overflow, %d bytes dropped", __FUNCTION__, urb->actual_length);
		}
		spin_unlock (&dev->read_buffer_lock);
	}

resubmit:
	/* resubmit if we're still running */
	if (dev->interrupt_in_running && dev->udev) {
		retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC);
		if (retval) {
			err("%s: usb_submit_urb failed (%d)", __FUNCTION__, retval);
		}
	}

exit:
	dev->interrupt_in_done = 1;
	wake_up_interruptible (&dev->read_wait);

	lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer);
	dbg(4, "%s: leave, status %d", __FUNCTION__, urb->status);
}


/**
 *	tower_interrupt_out_callback
 */
static void tower_interrupt_out_callback (struct urb *urb, struct pt_regs *regs)
{
	struct lego_usb_tower *dev = (struct lego_usb_tower *)urb->context;

	dbg(4, "%s: enter, status %d", __FUNCTION__, urb->status);
	lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer);

	/* sync/async unlink faults aren't errors */
	if (urb->status && !(urb->status == -ENOENT ||
			     urb->status == -ECONNRESET ||
			     urb->status == -ESHUTDOWN)) {
		dbg(1, "%s - nonzero write bulk status received: %d",
		    __FUNCTION__, urb->status);
	}

	dev->interrupt_out_busy = 0;
	wake_up_interruptible(&dev->write_wait);

	lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer);
	dbg(4, "%s: leave, status %d", __FUNCTION__, urb->status);
}


/**
 *	tower_probe
 *
 *	Called by the usb core when a new device is connected that it thinks
 *	this driver might be interested in.
 */
static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id)
{
	struct usb_device *udev = interface_to_usbdev(interface);
	struct lego_usb_tower *dev = NULL;
	struct usb_host_interface *iface_desc;
	struct usb_endpoint_descriptor* endpoint;
	struct tower_reset_reply reset_reply;
	struct tower_get_version_reply get_version_reply;
	int i;
	int retval = -ENOMEM;
	int result;

	dbg(2, "%s: enter", __FUNCTION__);

	if (udev == NULL) {
		info ("udev is NULL.");
	}

	/* See if the device offered us matches what we can accept */
	if ((udev->descriptor.idVendor != LEGO_USB_TOWER_VENDOR_ID) ||
	    (udev->descriptor.idProduct != LEGO_USB_TOWER_PRODUCT_ID)) {
		return -ENODEV;
	}


	/* allocate memory for our device state and intialize it */

	dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL);

	if (dev == NULL) {
		err ("Out of memory");
		goto exit;
	}

	init_MUTEX (&dev->sem);

	dev->udev = udev;
	dev->open_count = 0;

	dev->read_buffer = NULL;
	dev->read_buffer_length = 0;
	dev->read_packet_length = 0;
	spin_lock_init (&dev->read_buffer_lock);
	dev->packet_timeout_jiffies = packet_timeout * HZ / 1000;
	dev->read_last_arrival = jiffies;

	init_waitqueue_head (&dev->read_wait);
	init_waitqueue_head (&dev->write_wait);

	dev->interrupt_in_buffer = NULL;
	dev->interrupt_in_endpoint = NULL;
	dev->interrupt_in_urb = NULL;
	dev->interrupt_in_running = 0;
	dev->interrupt_in_done = 0;

	dev->interrupt_out_buffer = NULL;
	dev->interrupt_out_endpoint = NULL;
	dev->interrupt_out_urb = NULL;
	dev->interrupt_out_busy = 0;

	iface_desc = interface->cur_altsetting;

	/* set up the endpoint information */
	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
		endpoint = &iface_desc->endpoint[i].desc;

		if (((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN) &&
		    ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT)) {
			dev->interrupt_in_endpoint = endpoint;
		}

		if (((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT) &&
		    ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT)) {
			dev->interrupt_out_endpoint = endpoint;
		}
	}
	if(dev->interrupt_in_endpoint == NULL) {
		err("interrupt in endpoint not found");
		goto error;
	}
	if (dev->interrupt_out_endpoint == NULL) {
		err("interrupt out endpoint not found");
		goto error;
	}

	dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL);
	if (!dev->read_buffer) {
		err("Couldn't allocate read_buffer");
		goto error;
	}
	dev->interrupt_in_buffer = kmalloc (dev->interrupt_in_endpoint->wMaxPacketSize, GFP_KERNEL);
	if (!dev->interrupt_in_buffer) {
		err("Couldn't allocate interrupt_in_buffer");
		goto error;
	}
	dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!dev->interrupt_in_urb) {
		err("Couldn't allocate interrupt_in_urb");
		goto error;
	}
	dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL);
	if (!dev->interrupt_out_buffer) {
		err("Couldn't allocate interrupt_out_buffer");
		goto error;
	}
	dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!dev->interrupt_out_urb) {
		err("Couldn't allocate interrupt_out_urb");
		goto error;
	}
	dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
	dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;

	/* we can register the device now, as it is ready */
	usb_set_intfdata (interface, dev);

	retval = usb_register_dev (interface, &tower_class);

	if (retval) {
		/* something prevented us from registering this driver */
		err ("Not able to get a minor for this device.");
		usb_set_intfdata (interface, NULL);
		goto error;
	}
	dev->minor = interface->minor;

	/* let the user know what node this device is now attached to */
	info ("LEGO USB Tower #%d now attached to major %d minor %d", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), USB_MAJOR, dev->minor);

	/* reset the tower */
	result = usb_control_msg (udev,
				  usb_rcvctrlpipe(udev, 0),
				  LEGO_USB_TOWER_REQUEST_RESET,
				  USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
				  0,
				  0,
				  &reset_reply,
				  sizeof(reset_reply),
				  HZ);
	if (result < 0) {
		err("LEGO USB Tower reset control request failed");
		retval = result;
		goto error;
	}

	/* get the firmware version and log it */
	result = usb_control_msg (udev,
				  usb_rcvctrlpipe(udev, 0),
				  LEGO_USB_TOWER_REQUEST_GET_VERSION,
				  USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
				  0,
				  0,
				  &get_version_reply,
				  sizeof(get_version_reply),
				  HZ);
	if (result < 0) {
		err("LEGO USB Tower get version control request failed");
		retval = result;
		goto error;
	}
	info("LEGO USB Tower firmware version is %d.%d build %d",
	     get_version_reply.major,
	     get_version_reply.minor,
	     le16_to_cpu(get_version_reply.build_no));


exit:
	dbg(2, "%s: leave, return value 0x%.8lx (dev)", __FUNCTION__, (long) dev);

	return retval;

error:
	tower_delete(dev);
	return retval;
}


/**
 *	tower_disconnect
 *
 *	Called by the usb core when the device is removed from the system.
 */
static void tower_disconnect (struct usb_interface *interface)
{
	struct lego_usb_tower *dev;
	int minor;

	dbg(2, "%s: enter", __FUNCTION__);

	down (&disconnect_sem);

	dev = usb_get_intfdata (interface);
	usb_set_intfdata (interface, NULL);


	down (&dev->sem);

	minor = dev->minor;

	/* give back our minor */
	usb_deregister_dev (interface, &tower_class);

	/* if the device is not opened, then we clean up right now */
	if (!dev->open_count) {
		up (&dev->sem);
		tower_delete (dev);
	} else {
		dev->udev = NULL;
		up (&dev->sem);
	}

	up (&disconnect_sem);

	info("LEGO USB Tower #%d now disconnected", (minor - LEGO_USB_TOWER_MINOR_BASE));

	dbg(2, "%s: leave", __FUNCTION__);
}



/**
 *	lego_usb_tower_init
 */
static int __init lego_usb_tower_init(void)
{
	int result;
	int retval = 0;

	dbg(2, "%s: enter", __FUNCTION__);

	/* register this driver with the USB subsystem */
	result = usb_register(&tower_driver);
	if (result < 0) {
		err("usb_register failed for the "__FILE__" driver. Error number %d", result);
		retval = -1;
		goto exit;
	}

	info(DRIVER_DESC " " DRIVER_VERSION);

exit:
	dbg(2, "%s: leave, return value %d", __FUNCTION__, retval);

	return retval;
}


/**
 *	lego_usb_tower_exit
 */
static void __exit lego_usb_tower_exit(void)
{
	dbg(2, "%s: enter", __FUNCTION__);

	/* deregister this driver with the USB subsystem */
	usb_deregister (&tower_driver);

	dbg(2, "%s: leave", __FUNCTION__);
}

module_init (lego_usb_tower_init);
module_exit (lego_usb_tower_exit);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
#ifdef MODULE_LICENSE
MODULE_LICENSE("GPL");
#endif