1 files changed, 360 insertions, 0 deletions
diff --git a/drivers/usb/usb-skeleton.c b/drivers/usb/usb-skeleton.c
new file mode 100644
index 000000000000..6051a646fe69
--- /dev/null
+++ b/drivers/usb/usb-skeleton.c
@@ -0,0 +1,360 @@
+/*
+ * USB Skeleton driver - 2.0
+ *
+ * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com)
+ *
+ *	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, version 2.
+ *
+ * This driver is based on the 2.6.3 version of drivers/usb/usb-skeleton.c 
+ * but has been rewritten to be easy to read and use, as no locks are now
+ * needed anymore.
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/kref.h>
+#include <asm/uaccess.h>
+#include <linux/usb.h>
+
+
+/* Define these values to match your devices */
+#define USB_SKEL_VENDOR_ID	0xfff0
+#define USB_SKEL_PRODUCT_ID	0xfff0
+
+/* table of devices that work with this driver */
+static struct usb_device_id skel_table [] = {
+	{ USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) },
+	{ }					/* Terminating entry */
+};
+MODULE_DEVICE_TABLE (usb, skel_table);
+
+
+/* Get a minor range for your devices from the usb maintainer */
+#define USB_SKEL_MINOR_BASE	192
+
+/* Structure to hold all of our device specific stuff */
+struct usb_skel {
+	struct usb_device *	udev;			/* the usb device for this device */
+	struct usb_interface *	interface;		/* the interface for this device */
+	unsigned char *		bulk_in_buffer;		/* the buffer to receive data */
+	size_t			bulk_in_size;		/* the size of the receive buffer */
+	__u8			bulk_in_endpointAddr;	/* the address of the bulk in endpoint */
+	__u8			bulk_out_endpointAddr;	/* the address of the bulk out endpoint */
+	struct kref		kref;
+};
+#define to_skel_dev(d) container_of(d, struct usb_skel, kref)
+
+static struct usb_driver skel_driver;
+
+static void skel_delete(struct kref *kref)
+{	
+	struct usb_skel *dev = to_skel_dev(kref);
+
+	usb_put_dev(dev->udev);
+	kfree (dev->bulk_in_buffer);
+	kfree (dev);
+}
+
+static int skel_open(struct inode *inode, struct file *file)
+{
+	struct usb_skel *dev;
+	struct usb_interface *interface;
+	int subminor;
+	int retval = 0;
+
+	subminor = iminor(inode);
+
+	interface = usb_find_interface(&skel_driver, subminor);
+	if (!interface) {
+		err ("%s - error, can't find device for minor %d",
+		     __FUNCTION__, subminor);
+		retval = -ENODEV;
+		goto exit;
+	}
+
+	dev = usb_get_intfdata(interface);
+	if (!dev) {
+		retval = -ENODEV;
+		goto exit;
+	}
+
+	/* increment our usage count for the device */
+	kref_get(&dev->kref);
+
+	/* save our object in the file's private structure */
+	file->private_data = dev;
+
+exit:
+	return retval;
+}
+
+static int skel_release(struct inode *inode, struct file *file)
+{
+	struct usb_skel *dev;
+
+	dev = (struct usb_skel *)file->private_data;
+	if (dev == NULL)
+		return -ENODEV;
+
+	/* decrement the count on our device */
+	kref_put(&dev->kref, skel_delete);
+	return 0;
+}
+
+static ssize_t skel_read(struct file *file, char *buffer, size_t count, loff_t *ppos)
+{
+	struct usb_skel *dev;
+	int retval = 0;
+	int bytes_read;
+
+	dev = (struct usb_skel *)file->private_data;
+	
+	/* do a blocking bulk read to get data from the device */
+	retval = usb_bulk_msg(dev->udev,
+			      usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr),
+			      dev->bulk_in_buffer,
+			      min(dev->bulk_in_size, count),
+			      &bytes_read, 10000);
+
+	/* if the read was successful, copy the data to userspace */
+	if (!retval) {
+		if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read))
+			retval = -EFAULT;
+		else
+			retval = bytes_read;
+	}
+
+	return retval;
+}
+
+static void skel_write_bulk_callback(struct urb *urb, struct pt_regs *regs)
+{
+	struct usb_skel *dev;
+
+	dev = (struct usb_skel *)urb->context;
+
+	/* sync/async unlink faults aren't errors */
+	if (urb->status && 
+	    !(urb->status == -ENOENT || 
+	      urb->status == -ECONNRESET ||
+	      urb->status == -ESHUTDOWN)) {
+		dbg("%s - nonzero write bulk status received: %d",
+		    __FUNCTION__, urb->status);
+	}
+
+	/* free up our allocated buffer */
+	usb_buffer_free(urb->dev, urb->transfer_buffer_length, 
+			urb->transfer_buffer, urb->transfer_dma);
+}
+
+static ssize_t skel_write(struct file *file, const char *user_buffer, size_t count, loff_t *ppos)
+{
+	struct usb_skel *dev;
+	int retval = 0;
+	struct urb *urb = NULL;
+	char *buf = NULL;
+
+	dev = (struct usb_skel *)file->private_data;
+
+	/* verify that we actually have some data to write */
+	if (count == 0)
+		goto exit;
+
+	/* create a urb, and a buffer for it, and copy the data to the urb */
+	urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!urb) {
+		retval = -ENOMEM;
+		goto error;
+	}
+
+	buf = usb_buffer_alloc(dev->udev, count, GFP_KERNEL, &urb->transfer_dma);
+	if (!buf) {
+		retval = -ENOMEM;
+		goto error;
+	}
+
+	if (copy_from_user(buf, user_buffer, count)) {
+		retval = -EFAULT;
+		goto error;
+	}
+
+	/* initialize the urb properly */
+	usb_fill_bulk_urb(urb, dev->udev,
+			  usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr),
+			  buf, count, skel_write_bulk_callback, dev);
+	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+
+	/* send the data out the bulk port */
+	retval = usb_submit_urb(urb, GFP_KERNEL);
+	if (retval) {
+		err("%s - failed submitting write urb, error %d", __FUNCTION__, retval);
+		goto error;
+	}
+
+	/* release our reference to this urb, the USB core will eventually free it entirely */
+	usb_free_urb(urb);
+
+exit:
+	return count;
+
+error:
+	usb_buffer_free(dev->udev, count, buf, urb->transfer_dma);
+	usb_free_urb(urb);
+	return retval;
+}
+
+static struct file_operations skel_fops = {
+	.owner =	THIS_MODULE,
+	.read =		skel_read,
+	.write =	skel_write,
+	.open =		skel_open,
+	.release =	skel_release,
+};
+
+/* 
+ * usb class driver info in order to get a minor number from the usb core,
+ * and to have the device registered with devfs and the driver core
+ */
+static struct usb_class_driver skel_class = {
+	.name =		"usb/skel%d",
+	.fops =		&skel_fops,
+	.mode =		S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH,
+	.minor_base =	USB_SKEL_MINOR_BASE,
+};
+
+static int skel_probe(struct usb_interface *interface, const struct usb_device_id *id)
+{
+	struct usb_skel *dev = NULL;
+	struct usb_host_interface *iface_desc;
+	struct usb_endpoint_descriptor *endpoint;
+	size_t buffer_size;
+	int i;
+	int retval = -ENOMEM;
+
+	/* allocate memory for our device state and initialize it */
+	dev = kmalloc(sizeof(*dev), GFP_KERNEL);
+	if (dev == NULL) {
+		err("Out of memory");
+		goto error;
+	}
+	memset(dev, 0x00, sizeof(*dev));
+	kref_init(&dev->kref);
+
+	dev->udev = usb_get_dev(interface_to_usbdev(interface));
+	dev->interface = interface;
+
+	/* set up the endpoint information */
+	/* use only the first bulk-in and bulk-out endpoints */
+	iface_desc = interface->cur_altsetting;
+	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
+		endpoint = &iface_desc->endpoint[i].desc;
+
+		if (!dev->bulk_in_endpointAddr &&
+		    (endpoint->bEndpointAddress & USB_DIR_IN) &&
+		    ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
+					== USB_ENDPOINT_XFER_BULK)) {
+			/* we found a bulk in endpoint */
+			buffer_size = le16_to_cpu(endpoint->wMaxPacketSize);
+			dev->bulk_in_size = buffer_size;
+			dev->bulk_in_endpointAddr = endpoint->bEndpointAddress;
+			dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL);
+			if (!dev->bulk_in_buffer) {
+				err("Could not allocate bulk_in_buffer");
+				goto error;
+			}
+		}
+
+		if (!dev->bulk_out_endpointAddr &&
+		    !(endpoint->bEndpointAddress & USB_DIR_OUT) &&
+		    ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
+					== USB_ENDPOINT_XFER_BULK)) {
+			/* we found a bulk out endpoint */
+			dev->bulk_out_endpointAddr = endpoint->bEndpointAddress;
+		}
+	}
+	if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) {
+		err("Could not find both bulk-in and bulk-out endpoints");
+		goto error;
+	}
+
+	/* save our data pointer in this interface device */
+	usb_set_intfdata(interface, dev);
+
+	/* we can register the device now, as it is ready */
+	retval = usb_register_dev(interface, &skel_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;
+	}
+
+	/* let the user know what node this device is now attached to */
+	info("USB Skeleton device now attached to USBSkel-%d", interface->minor);
+	return 0;
+
+error:
+	if (dev)
+		kref_put(&dev->kref, skel_delete);
+	return retval;
+}
+
+static void skel_disconnect(struct usb_interface *interface)
+{
+	struct usb_skel *dev;
+	int minor = interface->minor;
+
+	/* prevent skel_open() from racing skel_disconnect() */
+	lock_kernel();
+
+	dev = usb_get_intfdata(interface);
+	usb_set_intfdata(interface, NULL);
+
+	/* give back our minor */
+	usb_deregister_dev(interface, &skel_class);
+
+	unlock_kernel();
+
+	/* decrement our usage count */
+	kref_put(&dev->kref, skel_delete);
+
+	info("USB Skeleton #%d now disconnected", minor);
+}
+
+static struct usb_driver skel_driver = {
+	.owner =	THIS_MODULE,
+	.name =		"skeleton",
+	.probe =	skel_probe,
+	.disconnect =	skel_disconnect,
+	.id_table =	skel_table,
+};
+
+static int __init usb_skel_init(void)
+{
+	int result;
+
+	/* register this driver with the USB subsystem */
+	result = usb_register(&skel_driver);
+	if (result)
+		err("usb_register failed. Error number %d", result);
+
+	return result;
+}
+
+static void __exit usb_skel_exit(void)
+{
+	/* deregister this driver with the USB subsystem */
+	usb_deregister(&skel_driver);
+}
+
+module_init (usb_skel_init);
+module_exit (usb_skel_exit);
+
+MODULE_LICENSE("GPL");