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");