1*1da177e4SLinus Torvalds /* 2*1da177e4SLinus Torvalds * USB Skeleton driver - 2.0 3*1da177e4SLinus Torvalds * 4*1da177e4SLinus Torvalds * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com) 5*1da177e4SLinus Torvalds * 6*1da177e4SLinus Torvalds * This program is free software; you can redistribute it and/or 7*1da177e4SLinus Torvalds * modify it under the terms of the GNU General Public License as 8*1da177e4SLinus Torvalds * published by the Free Software Foundation, version 2. 9*1da177e4SLinus Torvalds * 10*1da177e4SLinus Torvalds * This driver is based on the 2.6.3 version of drivers/usb/usb-skeleton.c 11*1da177e4SLinus Torvalds * but has been rewritten to be easy to read and use, as no locks are now 12*1da177e4SLinus Torvalds * needed anymore. 13*1da177e4SLinus Torvalds * 14*1da177e4SLinus Torvalds */ 15*1da177e4SLinus Torvalds 16*1da177e4SLinus Torvalds #include <linux/config.h> 17*1da177e4SLinus Torvalds #include <linux/kernel.h> 18*1da177e4SLinus Torvalds #include <linux/errno.h> 19*1da177e4SLinus Torvalds #include <linux/init.h> 20*1da177e4SLinus Torvalds #include <linux/slab.h> 21*1da177e4SLinus Torvalds #include <linux/module.h> 22*1da177e4SLinus Torvalds #include <linux/kref.h> 23*1da177e4SLinus Torvalds #include <asm/uaccess.h> 24*1da177e4SLinus Torvalds #include <linux/usb.h> 25*1da177e4SLinus Torvalds 26*1da177e4SLinus Torvalds 27*1da177e4SLinus Torvalds /* Define these values to match your devices */ 28*1da177e4SLinus Torvalds #define USB_SKEL_VENDOR_ID 0xfff0 29*1da177e4SLinus Torvalds #define USB_SKEL_PRODUCT_ID 0xfff0 30*1da177e4SLinus Torvalds 31*1da177e4SLinus Torvalds /* table of devices that work with this driver */ 32*1da177e4SLinus Torvalds static struct usb_device_id skel_table [] = { 33*1da177e4SLinus Torvalds { USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) }, 34*1da177e4SLinus Torvalds { } /* Terminating entry */ 35*1da177e4SLinus Torvalds }; 36*1da177e4SLinus Torvalds MODULE_DEVICE_TABLE (usb, skel_table); 37*1da177e4SLinus Torvalds 38*1da177e4SLinus Torvalds 39*1da177e4SLinus Torvalds /* Get a minor range for your devices from the usb maintainer */ 40*1da177e4SLinus Torvalds #define USB_SKEL_MINOR_BASE 192 41*1da177e4SLinus Torvalds 42*1da177e4SLinus Torvalds /* Structure to hold all of our device specific stuff */ 43*1da177e4SLinus Torvalds struct usb_skel { 44*1da177e4SLinus Torvalds struct usb_device * udev; /* the usb device for this device */ 45*1da177e4SLinus Torvalds struct usb_interface * interface; /* the interface for this device */ 46*1da177e4SLinus Torvalds unsigned char * bulk_in_buffer; /* the buffer to receive data */ 47*1da177e4SLinus Torvalds size_t bulk_in_size; /* the size of the receive buffer */ 48*1da177e4SLinus Torvalds __u8 bulk_in_endpointAddr; /* the address of the bulk in endpoint */ 49*1da177e4SLinus Torvalds __u8 bulk_out_endpointAddr; /* the address of the bulk out endpoint */ 50*1da177e4SLinus Torvalds struct kref kref; 51*1da177e4SLinus Torvalds }; 52*1da177e4SLinus Torvalds #define to_skel_dev(d) container_of(d, struct usb_skel, kref) 53*1da177e4SLinus Torvalds 54*1da177e4SLinus Torvalds static struct usb_driver skel_driver; 55*1da177e4SLinus Torvalds 56*1da177e4SLinus Torvalds static void skel_delete(struct kref *kref) 57*1da177e4SLinus Torvalds { 58*1da177e4SLinus Torvalds struct usb_skel *dev = to_skel_dev(kref); 59*1da177e4SLinus Torvalds 60*1da177e4SLinus Torvalds usb_put_dev(dev->udev); 61*1da177e4SLinus Torvalds kfree (dev->bulk_in_buffer); 62*1da177e4SLinus Torvalds kfree (dev); 63*1da177e4SLinus Torvalds } 64*1da177e4SLinus Torvalds 65*1da177e4SLinus Torvalds static int skel_open(struct inode *inode, struct file *file) 66*1da177e4SLinus Torvalds { 67*1da177e4SLinus Torvalds struct usb_skel *dev; 68*1da177e4SLinus Torvalds struct usb_interface *interface; 69*1da177e4SLinus Torvalds int subminor; 70*1da177e4SLinus Torvalds int retval = 0; 71*1da177e4SLinus Torvalds 72*1da177e4SLinus Torvalds subminor = iminor(inode); 73*1da177e4SLinus Torvalds 74*1da177e4SLinus Torvalds interface = usb_find_interface(&skel_driver, subminor); 75*1da177e4SLinus Torvalds if (!interface) { 76*1da177e4SLinus Torvalds err ("%s - error, can't find device for minor %d", 77*1da177e4SLinus Torvalds __FUNCTION__, subminor); 78*1da177e4SLinus Torvalds retval = -ENODEV; 79*1da177e4SLinus Torvalds goto exit; 80*1da177e4SLinus Torvalds } 81*1da177e4SLinus Torvalds 82*1da177e4SLinus Torvalds dev = usb_get_intfdata(interface); 83*1da177e4SLinus Torvalds if (!dev) { 84*1da177e4SLinus Torvalds retval = -ENODEV; 85*1da177e4SLinus Torvalds goto exit; 86*1da177e4SLinus Torvalds } 87*1da177e4SLinus Torvalds 88*1da177e4SLinus Torvalds /* increment our usage count for the device */ 89*1da177e4SLinus Torvalds kref_get(&dev->kref); 90*1da177e4SLinus Torvalds 91*1da177e4SLinus Torvalds /* save our object in the file's private structure */ 92*1da177e4SLinus Torvalds file->private_data = dev; 93*1da177e4SLinus Torvalds 94*1da177e4SLinus Torvalds exit: 95*1da177e4SLinus Torvalds return retval; 96*1da177e4SLinus Torvalds } 97*1da177e4SLinus Torvalds 98*1da177e4SLinus Torvalds static int skel_release(struct inode *inode, struct file *file) 99*1da177e4SLinus Torvalds { 100*1da177e4SLinus Torvalds struct usb_skel *dev; 101*1da177e4SLinus Torvalds 102*1da177e4SLinus Torvalds dev = (struct usb_skel *)file->private_data; 103*1da177e4SLinus Torvalds if (dev == NULL) 104*1da177e4SLinus Torvalds return -ENODEV; 105*1da177e4SLinus Torvalds 106*1da177e4SLinus Torvalds /* decrement the count on our device */ 107*1da177e4SLinus Torvalds kref_put(&dev->kref, skel_delete); 108*1da177e4SLinus Torvalds return 0; 109*1da177e4SLinus Torvalds } 110*1da177e4SLinus Torvalds 111*1da177e4SLinus Torvalds static ssize_t skel_read(struct file *file, char *buffer, size_t count, loff_t *ppos) 112*1da177e4SLinus Torvalds { 113*1da177e4SLinus Torvalds struct usb_skel *dev; 114*1da177e4SLinus Torvalds int retval = 0; 115*1da177e4SLinus Torvalds int bytes_read; 116*1da177e4SLinus Torvalds 117*1da177e4SLinus Torvalds dev = (struct usb_skel *)file->private_data; 118*1da177e4SLinus Torvalds 119*1da177e4SLinus Torvalds /* do a blocking bulk read to get data from the device */ 120*1da177e4SLinus Torvalds retval = usb_bulk_msg(dev->udev, 121*1da177e4SLinus Torvalds usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr), 122*1da177e4SLinus Torvalds dev->bulk_in_buffer, 123*1da177e4SLinus Torvalds min(dev->bulk_in_size, count), 124*1da177e4SLinus Torvalds &bytes_read, 10000); 125*1da177e4SLinus Torvalds 126*1da177e4SLinus Torvalds /* if the read was successful, copy the data to userspace */ 127*1da177e4SLinus Torvalds if (!retval) { 128*1da177e4SLinus Torvalds if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read)) 129*1da177e4SLinus Torvalds retval = -EFAULT; 130*1da177e4SLinus Torvalds else 131*1da177e4SLinus Torvalds retval = bytes_read; 132*1da177e4SLinus Torvalds } 133*1da177e4SLinus Torvalds 134*1da177e4SLinus Torvalds return retval; 135*1da177e4SLinus Torvalds } 136*1da177e4SLinus Torvalds 137*1da177e4SLinus Torvalds static void skel_write_bulk_callback(struct urb *urb, struct pt_regs *regs) 138*1da177e4SLinus Torvalds { 139*1da177e4SLinus Torvalds struct usb_skel *dev; 140*1da177e4SLinus Torvalds 141*1da177e4SLinus Torvalds dev = (struct usb_skel *)urb->context; 142*1da177e4SLinus Torvalds 143*1da177e4SLinus Torvalds /* sync/async unlink faults aren't errors */ 144*1da177e4SLinus Torvalds if (urb->status && 145*1da177e4SLinus Torvalds !(urb->status == -ENOENT || 146*1da177e4SLinus Torvalds urb->status == -ECONNRESET || 147*1da177e4SLinus Torvalds urb->status == -ESHUTDOWN)) { 148*1da177e4SLinus Torvalds dbg("%s - nonzero write bulk status received: %d", 149*1da177e4SLinus Torvalds __FUNCTION__, urb->status); 150*1da177e4SLinus Torvalds } 151*1da177e4SLinus Torvalds 152*1da177e4SLinus Torvalds /* free up our allocated buffer */ 153*1da177e4SLinus Torvalds usb_buffer_free(urb->dev, urb->transfer_buffer_length, 154*1da177e4SLinus Torvalds urb->transfer_buffer, urb->transfer_dma); 155*1da177e4SLinus Torvalds } 156*1da177e4SLinus Torvalds 157*1da177e4SLinus Torvalds static ssize_t skel_write(struct file *file, const char *user_buffer, size_t count, loff_t *ppos) 158*1da177e4SLinus Torvalds { 159*1da177e4SLinus Torvalds struct usb_skel *dev; 160*1da177e4SLinus Torvalds int retval = 0; 161*1da177e4SLinus Torvalds struct urb *urb = NULL; 162*1da177e4SLinus Torvalds char *buf = NULL; 163*1da177e4SLinus Torvalds 164*1da177e4SLinus Torvalds dev = (struct usb_skel *)file->private_data; 165*1da177e4SLinus Torvalds 166*1da177e4SLinus Torvalds /* verify that we actually have some data to write */ 167*1da177e4SLinus Torvalds if (count == 0) 168*1da177e4SLinus Torvalds goto exit; 169*1da177e4SLinus Torvalds 170*1da177e4SLinus Torvalds /* create a urb, and a buffer for it, and copy the data to the urb */ 171*1da177e4SLinus Torvalds urb = usb_alloc_urb(0, GFP_KERNEL); 172*1da177e4SLinus Torvalds if (!urb) { 173*1da177e4SLinus Torvalds retval = -ENOMEM; 174*1da177e4SLinus Torvalds goto error; 175*1da177e4SLinus Torvalds } 176*1da177e4SLinus Torvalds 177*1da177e4SLinus Torvalds buf = usb_buffer_alloc(dev->udev, count, GFP_KERNEL, &urb->transfer_dma); 178*1da177e4SLinus Torvalds if (!buf) { 179*1da177e4SLinus Torvalds retval = -ENOMEM; 180*1da177e4SLinus Torvalds goto error; 181*1da177e4SLinus Torvalds } 182*1da177e4SLinus Torvalds 183*1da177e4SLinus Torvalds if (copy_from_user(buf, user_buffer, count)) { 184*1da177e4SLinus Torvalds retval = -EFAULT; 185*1da177e4SLinus Torvalds goto error; 186*1da177e4SLinus Torvalds } 187*1da177e4SLinus Torvalds 188*1da177e4SLinus Torvalds /* initialize the urb properly */ 189*1da177e4SLinus Torvalds usb_fill_bulk_urb(urb, dev->udev, 190*1da177e4SLinus Torvalds usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr), 191*1da177e4SLinus Torvalds buf, count, skel_write_bulk_callback, dev); 192*1da177e4SLinus Torvalds urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 193*1da177e4SLinus Torvalds 194*1da177e4SLinus Torvalds /* send the data out the bulk port */ 195*1da177e4SLinus Torvalds retval = usb_submit_urb(urb, GFP_KERNEL); 196*1da177e4SLinus Torvalds if (retval) { 197*1da177e4SLinus Torvalds err("%s - failed submitting write urb, error %d", __FUNCTION__, retval); 198*1da177e4SLinus Torvalds goto error; 199*1da177e4SLinus Torvalds } 200*1da177e4SLinus Torvalds 201*1da177e4SLinus Torvalds /* release our reference to this urb, the USB core will eventually free it entirely */ 202*1da177e4SLinus Torvalds usb_free_urb(urb); 203*1da177e4SLinus Torvalds 204*1da177e4SLinus Torvalds exit: 205*1da177e4SLinus Torvalds return count; 206*1da177e4SLinus Torvalds 207*1da177e4SLinus Torvalds error: 208*1da177e4SLinus Torvalds usb_buffer_free(dev->udev, count, buf, urb->transfer_dma); 209*1da177e4SLinus Torvalds usb_free_urb(urb); 210*1da177e4SLinus Torvalds return retval; 211*1da177e4SLinus Torvalds } 212*1da177e4SLinus Torvalds 213*1da177e4SLinus Torvalds static struct file_operations skel_fops = { 214*1da177e4SLinus Torvalds .owner = THIS_MODULE, 215*1da177e4SLinus Torvalds .read = skel_read, 216*1da177e4SLinus Torvalds .write = skel_write, 217*1da177e4SLinus Torvalds .open = skel_open, 218*1da177e4SLinus Torvalds .release = skel_release, 219*1da177e4SLinus Torvalds }; 220*1da177e4SLinus Torvalds 221*1da177e4SLinus Torvalds /* 222*1da177e4SLinus Torvalds * usb class driver info in order to get a minor number from the usb core, 223*1da177e4SLinus Torvalds * and to have the device registered with devfs and the driver core 224*1da177e4SLinus Torvalds */ 225*1da177e4SLinus Torvalds static struct usb_class_driver skel_class = { 226*1da177e4SLinus Torvalds .name = "usb/skel%d", 227*1da177e4SLinus Torvalds .fops = &skel_fops, 228*1da177e4SLinus Torvalds .mode = S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH, 229*1da177e4SLinus Torvalds .minor_base = USB_SKEL_MINOR_BASE, 230*1da177e4SLinus Torvalds }; 231*1da177e4SLinus Torvalds 232*1da177e4SLinus Torvalds static int skel_probe(struct usb_interface *interface, const struct usb_device_id *id) 233*1da177e4SLinus Torvalds { 234*1da177e4SLinus Torvalds struct usb_skel *dev = NULL; 235*1da177e4SLinus Torvalds struct usb_host_interface *iface_desc; 236*1da177e4SLinus Torvalds struct usb_endpoint_descriptor *endpoint; 237*1da177e4SLinus Torvalds size_t buffer_size; 238*1da177e4SLinus Torvalds int i; 239*1da177e4SLinus Torvalds int retval = -ENOMEM; 240*1da177e4SLinus Torvalds 241*1da177e4SLinus Torvalds /* allocate memory for our device state and initialize it */ 242*1da177e4SLinus Torvalds dev = kmalloc(sizeof(*dev), GFP_KERNEL); 243*1da177e4SLinus Torvalds if (dev == NULL) { 244*1da177e4SLinus Torvalds err("Out of memory"); 245*1da177e4SLinus Torvalds goto error; 246*1da177e4SLinus Torvalds } 247*1da177e4SLinus Torvalds memset(dev, 0x00, sizeof(*dev)); 248*1da177e4SLinus Torvalds kref_init(&dev->kref); 249*1da177e4SLinus Torvalds 250*1da177e4SLinus Torvalds dev->udev = usb_get_dev(interface_to_usbdev(interface)); 251*1da177e4SLinus Torvalds dev->interface = interface; 252*1da177e4SLinus Torvalds 253*1da177e4SLinus Torvalds /* set up the endpoint information */ 254*1da177e4SLinus Torvalds /* use only the first bulk-in and bulk-out endpoints */ 255*1da177e4SLinus Torvalds iface_desc = interface->cur_altsetting; 256*1da177e4SLinus Torvalds for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { 257*1da177e4SLinus Torvalds endpoint = &iface_desc->endpoint[i].desc; 258*1da177e4SLinus Torvalds 259*1da177e4SLinus Torvalds if (!dev->bulk_in_endpointAddr && 260*1da177e4SLinus Torvalds (endpoint->bEndpointAddress & USB_DIR_IN) && 261*1da177e4SLinus Torvalds ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) 262*1da177e4SLinus Torvalds == USB_ENDPOINT_XFER_BULK)) { 263*1da177e4SLinus Torvalds /* we found a bulk in endpoint */ 264*1da177e4SLinus Torvalds buffer_size = le16_to_cpu(endpoint->wMaxPacketSize); 265*1da177e4SLinus Torvalds dev->bulk_in_size = buffer_size; 266*1da177e4SLinus Torvalds dev->bulk_in_endpointAddr = endpoint->bEndpointAddress; 267*1da177e4SLinus Torvalds dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL); 268*1da177e4SLinus Torvalds if (!dev->bulk_in_buffer) { 269*1da177e4SLinus Torvalds err("Could not allocate bulk_in_buffer"); 270*1da177e4SLinus Torvalds goto error; 271*1da177e4SLinus Torvalds } 272*1da177e4SLinus Torvalds } 273*1da177e4SLinus Torvalds 274*1da177e4SLinus Torvalds if (!dev->bulk_out_endpointAddr && 275*1da177e4SLinus Torvalds !(endpoint->bEndpointAddress & USB_DIR_OUT) && 276*1da177e4SLinus Torvalds ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) 277*1da177e4SLinus Torvalds == USB_ENDPOINT_XFER_BULK)) { 278*1da177e4SLinus Torvalds /* we found a bulk out endpoint */ 279*1da177e4SLinus Torvalds dev->bulk_out_endpointAddr = endpoint->bEndpointAddress; 280*1da177e4SLinus Torvalds } 281*1da177e4SLinus Torvalds } 282*1da177e4SLinus Torvalds if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) { 283*1da177e4SLinus Torvalds err("Could not find both bulk-in and bulk-out endpoints"); 284*1da177e4SLinus Torvalds goto error; 285*1da177e4SLinus Torvalds } 286*1da177e4SLinus Torvalds 287*1da177e4SLinus Torvalds /* save our data pointer in this interface device */ 288*1da177e4SLinus Torvalds usb_set_intfdata(interface, dev); 289*1da177e4SLinus Torvalds 290*1da177e4SLinus Torvalds /* we can register the device now, as it is ready */ 291*1da177e4SLinus Torvalds retval = usb_register_dev(interface, &skel_class); 292*1da177e4SLinus Torvalds if (retval) { 293*1da177e4SLinus Torvalds /* something prevented us from registering this driver */ 294*1da177e4SLinus Torvalds err("Not able to get a minor for this device."); 295*1da177e4SLinus Torvalds usb_set_intfdata(interface, NULL); 296*1da177e4SLinus Torvalds goto error; 297*1da177e4SLinus Torvalds } 298*1da177e4SLinus Torvalds 299*1da177e4SLinus Torvalds /* let the user know what node this device is now attached to */ 300*1da177e4SLinus Torvalds info("USB Skeleton device now attached to USBSkel-%d", interface->minor); 301*1da177e4SLinus Torvalds return 0; 302*1da177e4SLinus Torvalds 303*1da177e4SLinus Torvalds error: 304*1da177e4SLinus Torvalds if (dev) 305*1da177e4SLinus Torvalds kref_put(&dev->kref, skel_delete); 306*1da177e4SLinus Torvalds return retval; 307*1da177e4SLinus Torvalds } 308*1da177e4SLinus Torvalds 309*1da177e4SLinus Torvalds static void skel_disconnect(struct usb_interface *interface) 310*1da177e4SLinus Torvalds { 311*1da177e4SLinus Torvalds struct usb_skel *dev; 312*1da177e4SLinus Torvalds int minor = interface->minor; 313*1da177e4SLinus Torvalds 314*1da177e4SLinus Torvalds /* prevent skel_open() from racing skel_disconnect() */ 315*1da177e4SLinus Torvalds lock_kernel(); 316*1da177e4SLinus Torvalds 317*1da177e4SLinus Torvalds dev = usb_get_intfdata(interface); 318*1da177e4SLinus Torvalds usb_set_intfdata(interface, NULL); 319*1da177e4SLinus Torvalds 320*1da177e4SLinus Torvalds /* give back our minor */ 321*1da177e4SLinus Torvalds usb_deregister_dev(interface, &skel_class); 322*1da177e4SLinus Torvalds 323*1da177e4SLinus Torvalds unlock_kernel(); 324*1da177e4SLinus Torvalds 325*1da177e4SLinus Torvalds /* decrement our usage count */ 326*1da177e4SLinus Torvalds kref_put(&dev->kref, skel_delete); 327*1da177e4SLinus Torvalds 328*1da177e4SLinus Torvalds info("USB Skeleton #%d now disconnected", minor); 329*1da177e4SLinus Torvalds } 330*1da177e4SLinus Torvalds 331*1da177e4SLinus Torvalds static struct usb_driver skel_driver = { 332*1da177e4SLinus Torvalds .owner = THIS_MODULE, 333*1da177e4SLinus Torvalds .name = "skeleton", 334*1da177e4SLinus Torvalds .probe = skel_probe, 335*1da177e4SLinus Torvalds .disconnect = skel_disconnect, 336*1da177e4SLinus Torvalds .id_table = skel_table, 337*1da177e4SLinus Torvalds }; 338*1da177e4SLinus Torvalds 339*1da177e4SLinus Torvalds static int __init usb_skel_init(void) 340*1da177e4SLinus Torvalds { 341*1da177e4SLinus Torvalds int result; 342*1da177e4SLinus Torvalds 343*1da177e4SLinus Torvalds /* register this driver with the USB subsystem */ 344*1da177e4SLinus Torvalds result = usb_register(&skel_driver); 345*1da177e4SLinus Torvalds if (result) 346*1da177e4SLinus Torvalds err("usb_register failed. Error number %d", result); 347*1da177e4SLinus Torvalds 348*1da177e4SLinus Torvalds return result; 349*1da177e4SLinus Torvalds } 350*1da177e4SLinus Torvalds 351*1da177e4SLinus Torvalds static void __exit usb_skel_exit(void) 352*1da177e4SLinus Torvalds { 353*1da177e4SLinus Torvalds /* deregister this driver with the USB subsystem */ 354*1da177e4SLinus Torvalds usb_deregister(&skel_driver); 355*1da177e4SLinus Torvalds } 356*1da177e4SLinus Torvalds 357*1da177e4SLinus Torvalds module_init (usb_skel_init); 358*1da177e4SLinus Torvalds module_exit (usb_skel_exit); 359*1da177e4SLinus Torvalds 360*1da177e4SLinus Torvalds MODULE_LICENSE("GPL"); 361