| /* |
| * 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/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 |
| |
| /* our private defines. if this grows any larger, use your own .h file */ |
| #define MAX_TRANSFER ( PAGE_SIZE - 512 ) |
| #define WRITES_IN_FLIGHT 8 |
| |
| /* 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 */ |
| struct semaphore limit_sem; /* limiting the number of writes in progress */ |
| 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); |
| up(&dev->limit_sem); |
| } |
| |
| 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; |
| size_t writesize = min(count, (size_t)MAX_TRANSFER); |
| |
| dev = (struct usb_skel *)file->private_data; |
| |
| /* verify that we actually have some data to write */ |
| if (count == 0) |
| goto exit; |
| |
| /* limit the number of URBs in flight to stop a user from using up all RAM */ |
| if (down_interruptible(&dev->limit_sem)) { |
| retval = -ERESTARTSYS; |
| 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, writesize, GFP_KERNEL, &urb->transfer_dma); |
| if (!buf) { |
| retval = -ENOMEM; |
| goto error; |
| } |
| |
| if (copy_from_user(buf, user_buffer, writesize)) { |
| retval = -EFAULT; |
| goto error; |
| } |
| |
| /* initialize the urb properly */ |
| usb_fill_bulk_urb(urb, dev->udev, |
| usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr), |
| buf, writesize, 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 writesize; |
| |
| error: |
| usb_buffer_free(dev->udev, writesize, buf, urb->transfer_dma); |
| usb_free_urb(urb); |
| up(&dev->limit_sem); |
| 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 the driver core |
| */ |
| static struct usb_class_driver skel_class = { |
| .name = "skel%d", |
| .fops = &skel_fops, |
| .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 = kzalloc(sizeof(*dev), GFP_KERNEL); |
| if (dev == NULL) { |
| err("Out of memory"); |
| goto error; |
| } |
| kref_init(&dev->kref); |
| sema_init(&dev->limit_sem, WRITES_IN_FLIGHT); |
| |
| 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_ENDPOINT_DIR_MASK) |
| == 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_ENDPOINT_DIR_MASK) |
| == 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 = { |
| .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"); |