/* * USB Skeleton driver - 0.6 * * Copyright (c) 2001 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; either version 2 of * the License, or (at your option) any later version. * * * This driver is to be used as a skeleton driver to be able to create a * USB driver quickly. The design of it is based on the usb-serial and * dc2xx drivers. * * Thanks to Oliver Neukum and David Brownell for their help in debugging * this driver. * * TODO: * - fix urb->status race condition in write sequence * - move minor_table to a dynamic list. * * History: * * 2001_11_05 - 0.6 - fix minor locking problem in skel_disconnect. * Thanks to Pete Zaitcev for the fix. * 2001_09_04 - 0.5 - fix devfs bug in skel_disconnect. Thanks to wim delvaux * 2001_08_21 - 0.4 - more small bug fixes. * 2001_05_29 - 0.3 - more bug fixes based on review from linux-usb-devel * 2001_05_24 - 0.2 - bug fixes based on review from linux-usb-devel people * 2001_05_01 - 0.1 - first version * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_USB_DEBUG static int debug = 1; #else static int debug; #endif /* Use our own dbg macro */ #undef dbg #define dbg(format, arg...) do { if (debug) printk(KERN_DEBUG __FILE__ ": " format "\n" , ## arg); } while (0) /* Version Information */ #define DRIVER_VERSION "v0.4" #define DRIVER_AUTHOR "Greg Kroah-Hartman, greg@kroah.com" #define DRIVER_DESC "USB Skeleton Driver" /* Module paramaters */ MODULE_PARM(debug, "i"); MODULE_PARM_DESC(debug, "Debug enabled or not"); /* Define these values to match your device */ #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 200 /* we can have up to this number of device plugged in at once */ #define MAX_DEVICES 16 /* Structure to hold all of our device specific stuff */ struct usb_skel { struct usb_device * udev; /* save off the usb device pointer */ struct usb_interface * interface; /* the interface for this device */ devfs_handle_t devfs; /* devfs device node */ unsigned char minor; /* the starting minor number for this device */ unsigned char num_ports; /* the number of ports this device has */ char num_interrupt_in; /* number of interrupt in endpoints we have */ char num_bulk_in; /* number of bulk in endpoints we have */ char num_bulk_out; /* number of bulk out endpoints we have */ unsigned char * bulk_in_buffer; /* the buffer to receive data */ int bulk_in_size; /* the size of the receive buffer */ __u8 bulk_in_endpointAddr; /* the address of the bulk in endpoint */ unsigned char * bulk_out_buffer; /* the buffer to send data */ int bulk_out_size; /* the size of the send buffer */ struct urb * write_urb; /* the urb used to send data */ __u8 bulk_out_endpointAddr; /* the address of the bulk out endpoint */ struct tq_struct tqueue; /* task queue for line discipline waking up */ int open_count; /* number of times this port has been opened */ struct semaphore sem; /* locks this structure */ }; /* the global usb devfs handle */ extern devfs_handle_t usb_devfs_handle; /* local function prototypes */ static ssize_t skel_read (struct file *file, char *buffer, size_t count, loff_t *ppos); static ssize_t skel_write (struct file *file, const char *buffer, size_t count, loff_t *ppos); static int skel_ioctl (struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg); static int skel_open (struct inode *inode, struct file *file); static int skel_release (struct inode *inode, struct file *file); static void * skel_probe (struct usb_device *dev, unsigned int ifnum, const struct usb_device_id *id); static void skel_disconnect (struct usb_device *dev, void *ptr); static void skel_write_bulk_callback (struct urb *urb); /* array of pointers to our devices that are currently connected */ static struct usb_skel *minor_table[MAX_DEVICES]; /* lock to protect the minor_table structure */ static DECLARE_MUTEX (minor_table_mutex); /* file operations needed when we register this driver */ static struct file_operations skel_fops = { owner: THIS_MODULE, read: skel_read, write: skel_write, ioctl: skel_ioctl, open: skel_open, release: skel_release, }; /* usb specific object needed to register this driver with the usb subsystem */ static struct usb_driver skel_driver = { name: "skeleton", probe: skel_probe, disconnect: skel_disconnect, fops: &skel_fops, minor: USB_SKEL_MINOR_BASE, id_table: skel_table, }; /** * usb_skel_debug_data */ static inline void usb_skel_debug_data (const char *function, int size, const unsigned char *data) { int i; if (!debug) return; printk (KERN_DEBUG __FILE__": %s - length = %d, data = ", function, size); for (i = 0; i < size; ++i) { printk ("%.2x ", data[i]); } printk ("\n"); } /** * skel_delete */ static inline void skel_delete (struct usb_skel *dev) { minor_table[dev->minor] = NULL; if (dev->bulk_in_buffer != NULL) kfree (dev->bulk_in_buffer); if (dev->bulk_out_buffer != NULL) kfree (dev->bulk_out_buffer); if (dev->write_urb != NULL) usb_free_urb (dev->write_urb); kfree (dev); } /** * skel_open */ static int skel_open (struct inode *inode, struct file *file) { struct usb_skel *dev = NULL; int subminor; int retval = 0; dbg(__FUNCTION__); subminor = MINOR (inode->i_rdev) - USB_SKEL_MINOR_BASE; if ((subminor < 0) || (subminor >= MAX_DEVICES)) { return -ENODEV; } /* increment our usage count for the module */ MOD_INC_USE_COUNT; /* lock our minor table and get our local data for this minor */ down (&minor_table_mutex); dev = minor_table[subminor]; if (dev == NULL) { up (&minor_table_mutex); MOD_DEC_USE_COUNT; return -ENODEV; } /* lock this device */ down (&dev->sem); /* unlock the minor table */ up (&minor_table_mutex); /* increment our usage count for the driver */ ++dev->open_count; /* save our object in the file's private structure */ file->private_data = dev; /* unlock this device */ up (&dev->sem); return retval; } /** * skel_release */ static int skel_release (struct inode *inode, struct file *file) { struct usb_skel *dev; int retval = 0; dev = (struct usb_skel *)file->private_data; if (dev == NULL) { dbg (__FUNCTION__ " - object is NULL"); return -ENODEV; } dbg(__FUNCTION__ " - minor %d", dev->minor); /* lock our minor table */ down (&minor_table_mutex); /* lock our device */ down (&dev->sem); if (dev->open_count <= 0) { dbg (__FUNCTION__ " - device not opened"); retval = -ENODEV; goto exit_not_opened; } if (dev->udev == NULL) { /* the device was unplugged before the file was released */ up (&dev->sem); skel_delete (dev); MOD_DEC_USE_COUNT; up (&minor_table_mutex); return 0; } /* decrement our usage count for the device */ --dev->open_count; if (dev->open_count <= 0) { /* shutdown any bulk writes that might be going on */ usb_unlink_urb (dev->write_urb); dev->open_count = 0; } /* decrement our usage count for the module */ MOD_DEC_USE_COUNT; exit_not_opened: up (&dev->sem); up (&minor_table_mutex); return retval; } /** * skel_read */ static ssize_t skel_read (struct file *file, char *buffer, size_t count, loff_t *ppos) { struct usb_skel *dev; int retval = 0; dev = (struct usb_skel *)file->private_data; dbg(__FUNCTION__ " - minor %d, count = %d", dev->minor, count); /* lock this object */ down (&dev->sem); /* verify that the device wasn't unplugged */ if (dev->udev == NULL) { up (&dev->sem); return -ENODEV; } /* do an immediate 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, dev->bulk_in_size, &count, HZ*10); /* if the read was successful, copy the data to userspace */ if (!retval) { if (copy_to_user (buffer, dev->bulk_in_buffer, count)) retval = -EFAULT; else retval = count; } /* unlock the device */ up (&dev->sem); return retval; } /** * skel_write */ static ssize_t skel_write (struct file *file, const char *buffer, size_t count, loff_t *ppos) { struct usb_skel *dev; ssize_t bytes_written = 0; int retval = 0; dev = (struct usb_skel *)file->private_data; dbg(__FUNCTION__ " - minor %d, count = %d", dev->minor, count); /* lock this object */ down (&dev->sem); /* verify that the device wasn't unplugged */ if (dev->udev == NULL) { retval = -ENODEV; goto exit; } /* verify that we actually have some data to write */ if (count == 0) { dbg(__FUNCTION__ " - write request of 0 bytes"); goto exit; } /* see if we are already in the middle of a write */ if (dev->write_urb->status == -EINPROGRESS) { dbg (__FUNCTION__ " - already writing"); goto exit; } /* we can only write as much as 1 urb will hold */ bytes_written = (count > dev->bulk_out_size) ? dev->bulk_out_size : count; /* copy the data from userspace into our urb */ if (copy_from_user(dev->write_urb->transfer_buffer, buffer, bytes_written)) { retval = -EFAULT; goto exit; } usb_skel_debug_data (__FUNCTION__, bytes_written, dev->write_urb->transfer_buffer); /* set up our urb */ FILL_BULK_URB(dev->write_urb, dev->udev, usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr), dev->write_urb->transfer_buffer, bytes_written, skel_write_bulk_callback, dev); /* send the data out the bulk port */ retval = usb_submit_urb(dev->write_urb); if (retval) { err(__FUNCTION__ " - failed submitting write urb, error %d", retval); } else { retval = bytes_written; } exit: /* unlock the device */ up (&dev->sem); return retval; } /** * skel_ioctl */ static int skel_ioctl (struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { struct usb_skel *dev; dev = (struct usb_skel *)file->private_data; /* lock this object */ down (&dev->sem); /* verify that the device wasn't unplugged */ if (dev->udev == NULL) { up (&dev->sem); return -ENODEV; } dbg(__FUNCTION__ " - minor %d, cmd 0x%.4x, arg %ld", dev->minor, cmd, arg); /* fill in your device specific stuff here */ /* unlock the device */ up (&dev->sem); /* return that we did not understand this ioctl call */ return -ENOTTY; } /** * skel_write_bulk_callback */ static void skel_write_bulk_callback (struct urb *urb) { struct usb_skel *dev = (struct usb_skel *)urb->context; dbg(__FUNCTION__ " - minor %d", dev->minor); if ((urb->status != -ENOENT) && (urb->status != -ECONNRESET)) { dbg(__FUNCTION__ " - nonzero write bulk status received: %d", urb->status); return; } return; } /** * skel_probe * * Called by the usb core when a new device is connected that it thinks * this driver might be interested in. */ static void * skel_probe(struct usb_device *udev, unsigned int ifnum, const struct usb_device_id *id) { struct usb_skel *dev = NULL; struct usb_interface *interface; struct usb_interface_descriptor *iface_desc; struct usb_endpoint_descriptor *endpoint; int minor; int buffer_size; int i; char name[10]; /* See if the device offered us matches what we can accept */ if ((udev->descriptor.idVendor != USB_SKEL_VENDOR_ID) || (udev->descriptor.idProduct != USB_SKEL_PRODUCT_ID)) { return NULL; } /* select a "subminor" number (part of a minor number) */ down (&minor_table_mutex); for (minor = 0; minor < MAX_DEVICES; ++minor) { if (minor_table[minor] == NULL) break; } if (minor >= MAX_DEVICES) { info ("Too many devices plugged in, can not handle this device."); goto exit; } /* allocate memory for our device state and intialize it */ dev = kmalloc (sizeof(struct usb_skel), GFP_KERNEL); if (dev == NULL) { err ("Out of memory"); goto exit; } minor_table[minor] = dev; interface = &udev->actconfig->interface[ifnum]; init_MUTEX (&dev->sem); dev->udev = udev; dev->interface = interface; dev->minor = minor; /* set up the endpoint information */ /* check out the endpoints */ iface_desc = &interface->altsetting[0]; for (i = 0; i < iface_desc->bNumEndpoints; ++i) { endpoint = &iface_desc->endpoint[i]; if ((endpoint->bEndpointAddress & 0x80) && ((endpoint->bmAttributes & 3) == 0x02)) { /* we found a bulk in endpoint */ buffer_size = 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("Couldn't allocate bulk_in_buffer"); goto error; } } if (((endpoint->bEndpointAddress & 0x80) == 0x00) && ((endpoint->bmAttributes & 3) == 0x02)) { /* we found a bulk out endpoint */ dev->write_urb = usb_alloc_urb(0); if (!dev->write_urb) { err("No free urbs available"); goto error; } buffer_size = endpoint->wMaxPacketSize; dev->bulk_out_size = buffer_size; dev->bulk_out_endpointAddr = endpoint->bEndpointAddress; dev->bulk_out_buffer = kmalloc (buffer_size, GFP_KERNEL); if (!dev->bulk_out_buffer) { err("Couldn't allocate bulk_out_buffer"); goto error; } FILL_BULK_URB(dev->write_urb, udev, usb_sndbulkpipe(udev, endpoint->bEndpointAddress), dev->bulk_out_buffer, buffer_size, skel_write_bulk_callback, dev); } } /* initialize the devfs node for this device and register it */ sprintf(name, "skel%d", dev->minor); dev->devfs = devfs_register (usb_devfs_handle, name, DEVFS_FL_DEFAULT, USB_MAJOR, USB_SKEL_MINOR_BASE + dev->minor, S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH, &skel_fops, NULL); /* let the user know what node this device is now attached to */ info ("USB Skeleton device now attached to USBSkel%d", dev->minor); goto exit; error: skel_delete (dev); dev = NULL; exit: up (&minor_table_mutex); return dev; } /** * skel_disconnect * * Called by the usb core when the device is removed from the system. */ static void skel_disconnect(struct usb_device *udev, void *ptr) { struct usb_skel *dev; int minor; dev = (struct usb_skel *)ptr; down (&minor_table_mutex); down (&dev->sem); minor = dev->minor; /* remove our devfs node */ devfs_unregister(dev->devfs); /* if the device is not opened, then we clean up right now */ if (!dev->open_count) { up (&dev->sem); skel_delete (dev); } else { dev->udev = NULL; up (&dev->sem); } info("USB Skeleton #%d now disconnected", minor); up (&minor_table_mutex); } /** * usb_skel_init */ static int __init usb_skel_init(void) { int result; /* register this driver with the USB subsystem */ result = usb_register(&skel_driver); if (result < 0) { err("usb_register failed for the "__FILE__" driver. Error number %d", result); return -1; } info(DRIVER_DESC " " DRIVER_VERSION); return 0; } /** * usb_skel_exit */ 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_AUTHOR(DRIVER_AUTHOR); MODULE_DESCRIPTION(DRIVER_DESC); MODULE_LICENSE("GPL");