1 /***************************************************************************** 2 * USBLCD Kernel Driver * 3 * Version 1.05 * 4 * (C) 2005 Georges Toth <g.toth@e-biz.lu> * 5 * * 6 * This file is licensed under the GPL. See COPYING in the package. * 7 * Based on usb-skeleton.c 2.0 by Greg Kroah-Hartman (greg@kroah.com) * 8 * * 9 * * 10 * 28.02.05 Complete rewrite of the original usblcd.c driver, * 11 * based on usb_skeleton.c. * 12 * This new driver allows more than one USB-LCD to be connected * 13 * and controlled, at once * 14 *****************************************************************************/ 15 #include <linux/module.h> 16 #include <linux/kernel.h> 17 #include <linux/init.h> 18 #include <linux/slab.h> 19 #include <linux/errno.h> 20 #include <asm/uaccess.h> 21 #include <linux/usb.h> 22 23 #define DRIVER_VERSION "USBLCD Driver Version 1.05" 24 25 #define USBLCD_MINOR 144 26 27 #define IOCTL_GET_HARD_VERSION 1 28 #define IOCTL_GET_DRV_VERSION 2 29 30 31 static struct usb_device_id id_table [] = { 32 { .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, }, 33 { }, 34 }; 35 MODULE_DEVICE_TABLE (usb, id_table); 36 37 38 struct usb_lcd { 39 struct usb_device * udev; /* init: probe_lcd */ 40 struct usb_interface * interface; /* the interface for this device */ 41 unsigned char * bulk_in_buffer; /* the buffer to receive data */ 42 size_t bulk_in_size; /* the size of the receive buffer */ 43 __u8 bulk_in_endpointAddr; /* the address of the bulk in endpoint */ 44 __u8 bulk_out_endpointAddr; /* the address of the bulk out endpoint */ 45 struct kref kref; 46 }; 47 #define to_lcd_dev(d) container_of(d, struct usb_lcd, kref) 48 49 static struct usb_driver lcd_driver; 50 51 52 static void lcd_delete(struct kref *kref) 53 { 54 struct usb_lcd *dev = to_lcd_dev(kref); 55 56 usb_put_dev(dev->udev); 57 kfree (dev->bulk_in_buffer); 58 kfree (dev); 59 } 60 61 62 static int lcd_open(struct inode *inode, struct file *file) 63 { 64 struct usb_lcd *dev; 65 struct usb_interface *interface; 66 int subminor; 67 int retval = 0; 68 69 subminor = iminor(inode); 70 71 interface = usb_find_interface(&lcd_driver, subminor); 72 if (!interface) { 73 err ("USBLCD: %s - error, can't find device for minor %d", 74 __FUNCTION__, subminor); 75 retval = -ENODEV; 76 goto exit; 77 } 78 79 dev = usb_get_intfdata(interface); 80 if (!dev) { 81 retval = -ENODEV; 82 goto exit; 83 } 84 85 /* increment our usage count for the device */ 86 kref_get(&dev->kref); 87 88 /* save our object in the file's private structure */ 89 file->private_data = dev; 90 91 exit: 92 return retval; 93 } 94 95 static int lcd_release(struct inode *inode, struct file *file) 96 { 97 struct usb_lcd *dev; 98 99 dev = (struct usb_lcd *)file->private_data; 100 if (dev == NULL) 101 return -ENODEV; 102 103 /* decrement the count on our device */ 104 kref_put(&dev->kref, lcd_delete); 105 return 0; 106 } 107 108 static ssize_t lcd_read(struct file *file, char __user * buffer, size_t count, loff_t *ppos) 109 { 110 struct usb_lcd *dev; 111 int retval = 0; 112 int bytes_read; 113 114 dev = (struct usb_lcd *)file->private_data; 115 116 /* do a blocking bulk read to get data from the device */ 117 retval = usb_bulk_msg(dev->udev, 118 usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr), 119 dev->bulk_in_buffer, 120 min(dev->bulk_in_size, count), 121 &bytes_read, 10000); 122 123 /* if the read was successful, copy the data to userspace */ 124 if (!retval) { 125 if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read)) 126 retval = -EFAULT; 127 else 128 retval = bytes_read; 129 } 130 131 return retval; 132 } 133 134 static int lcd_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) 135 { 136 struct usb_lcd *dev; 137 u16 bcdDevice; 138 char buf[30]; 139 140 dev = (struct usb_lcd *)file->private_data; 141 if (dev == NULL) 142 return -ENODEV; 143 144 switch (cmd) { 145 case IOCTL_GET_HARD_VERSION: 146 bcdDevice = le16_to_cpu((dev->udev)->descriptor.bcdDevice); 147 sprintf(buf,"%1d%1d.%1d%1d", 148 (bcdDevice & 0xF000)>>12, 149 (bcdDevice & 0xF00)>>8, 150 (bcdDevice & 0xF0)>>4, 151 (bcdDevice & 0xF)); 152 if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0) 153 return -EFAULT; 154 break; 155 case IOCTL_GET_DRV_VERSION: 156 sprintf(buf,DRIVER_VERSION); 157 if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0) 158 return -EFAULT; 159 break; 160 default: 161 return -ENOTTY; 162 break; 163 } 164 165 return 0; 166 } 167 168 static void lcd_write_bulk_callback(struct urb *urb, struct pt_regs *regs) 169 { 170 struct usb_lcd *dev; 171 172 dev = (struct usb_lcd *)urb->context; 173 174 /* sync/async unlink faults aren't errors */ 175 if (urb->status && 176 !(urb->status == -ENOENT || 177 urb->status == -ECONNRESET || 178 urb->status == -ESHUTDOWN)) { 179 dbg("USBLCD: %s - nonzero write bulk status received: %d", 180 __FUNCTION__, urb->status); 181 } 182 183 /* free up our allocated buffer */ 184 usb_buffer_free(urb->dev, urb->transfer_buffer_length, 185 urb->transfer_buffer, urb->transfer_dma); 186 } 187 188 static ssize_t lcd_write(struct file *file, const char __user * user_buffer, size_t count, loff_t *ppos) 189 { 190 struct usb_lcd *dev; 191 int retval = 0; 192 struct urb *urb = NULL; 193 char *buf = NULL; 194 195 dev = (struct usb_lcd *)file->private_data; 196 197 /* verify that we actually have some data to write */ 198 if (count == 0) 199 goto exit; 200 201 /* create a urb, and a buffer for it, and copy the data to the urb */ 202 urb = usb_alloc_urb(0, GFP_KERNEL); 203 if (!urb) { 204 retval = -ENOMEM; 205 goto error; 206 } 207 208 buf = usb_buffer_alloc(dev->udev, count, GFP_KERNEL, &urb->transfer_dma); 209 if (!buf) { 210 retval = -ENOMEM; 211 goto error; 212 } 213 214 if (copy_from_user(buf, user_buffer, count)) { 215 retval = -EFAULT; 216 goto error; 217 } 218 219 /* initialize the urb properly */ 220 usb_fill_bulk_urb(urb, dev->udev, 221 usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr), 222 buf, count, lcd_write_bulk_callback, dev); 223 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 224 225 /* send the data out the bulk port */ 226 retval = usb_submit_urb(urb, GFP_KERNEL); 227 if (retval) { 228 err("USBLCD: %s - failed submitting write urb, error %d", __FUNCTION__, retval); 229 goto error; 230 } 231 232 /* release our reference to this urb, the USB core will eventually free it entirely */ 233 usb_free_urb(urb); 234 235 exit: 236 return count; 237 238 error: 239 usb_buffer_free(dev->udev, count, buf, urb->transfer_dma); 240 usb_free_urb(urb); 241 return retval; 242 } 243 244 static struct file_operations lcd_fops = { 245 .owner = THIS_MODULE, 246 .read = lcd_read, 247 .write = lcd_write, 248 .open = lcd_open, 249 .ioctl = lcd_ioctl, 250 .release = lcd_release, 251 }; 252 253 /* 254 * usb class driver info in order to get a minor number from the usb core, 255 * and to have the device registered with the driver core 256 */ 257 static struct usb_class_driver lcd_class = { 258 .name = "lcd%d", 259 .fops = &lcd_fops, 260 .minor_base = USBLCD_MINOR, 261 }; 262 263 static int lcd_probe(struct usb_interface *interface, const struct usb_device_id *id) 264 { 265 struct usb_lcd *dev = NULL; 266 struct usb_host_interface *iface_desc; 267 struct usb_endpoint_descriptor *endpoint; 268 size_t buffer_size; 269 int i; 270 int retval = -ENOMEM; 271 272 /* allocate memory for our device state and initialize it */ 273 dev = kmalloc(sizeof(*dev), GFP_KERNEL); 274 if (dev == NULL) { 275 err("Out of memory"); 276 goto error; 277 } 278 memset(dev, 0x00, sizeof(*dev)); 279 kref_init(&dev->kref); 280 281 dev->udev = usb_get_dev(interface_to_usbdev(interface)); 282 dev->interface = interface; 283 284 if (le16_to_cpu(dev->udev->descriptor.idProduct) != 0x0001) { 285 warn(KERN_INFO "USBLCD model not supported."); 286 return -ENODEV; 287 } 288 289 /* set up the endpoint information */ 290 /* use only the first bulk-in and bulk-out endpoints */ 291 iface_desc = interface->cur_altsetting; 292 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { 293 endpoint = &iface_desc->endpoint[i].desc; 294 295 if (!dev->bulk_in_endpointAddr && 296 (endpoint->bEndpointAddress & USB_DIR_IN) && 297 ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) 298 == USB_ENDPOINT_XFER_BULK)) { 299 /* we found a bulk in endpoint */ 300 buffer_size = le16_to_cpu(endpoint->wMaxPacketSize); 301 dev->bulk_in_size = buffer_size; 302 dev->bulk_in_endpointAddr = endpoint->bEndpointAddress; 303 dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL); 304 if (!dev->bulk_in_buffer) { 305 err("Could not allocate bulk_in_buffer"); 306 goto error; 307 } 308 } 309 310 if (!dev->bulk_out_endpointAddr && 311 !(endpoint->bEndpointAddress & USB_DIR_IN) && 312 ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) 313 == USB_ENDPOINT_XFER_BULK)) { 314 /* we found a bulk out endpoint */ 315 dev->bulk_out_endpointAddr = endpoint->bEndpointAddress; 316 } 317 } 318 if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) { 319 err("Could not find both bulk-in and bulk-out endpoints"); 320 goto error; 321 } 322 323 /* save our data pointer in this interface device */ 324 usb_set_intfdata(interface, dev); 325 326 /* we can register the device now, as it is ready */ 327 retval = usb_register_dev(interface, &lcd_class); 328 if (retval) { 329 /* something prevented us from registering this driver */ 330 err("Not able to get a minor for this device."); 331 usb_set_intfdata(interface, NULL); 332 goto error; 333 } 334 335 i = le16_to_cpu(dev->udev->descriptor.bcdDevice); 336 337 info("USBLCD Version %1d%1d.%1d%1d found at address %d", 338 (i & 0xF000)>>12,(i & 0xF00)>>8,(i & 0xF0)>>4,(i & 0xF), 339 dev->udev->devnum); 340 341 /* let the user know what node this device is now attached to */ 342 info("USB LCD device now attached to USBLCD-%d", interface->minor); 343 return 0; 344 345 error: 346 if (dev) 347 kref_put(&dev->kref, lcd_delete); 348 return retval; 349 } 350 351 static void lcd_disconnect(struct usb_interface *interface) 352 { 353 struct usb_lcd *dev; 354 int minor = interface->minor; 355 356 /* prevent skel_open() from racing skel_disconnect() */ 357 lock_kernel(); 358 359 dev = usb_get_intfdata(interface); 360 usb_set_intfdata(interface, NULL); 361 362 /* give back our minor */ 363 usb_deregister_dev(interface, &lcd_class); 364 365 unlock_kernel(); 366 367 /* decrement our usage count */ 368 kref_put(&dev->kref, lcd_delete); 369 370 info("USB LCD #%d now disconnected", minor); 371 } 372 373 static struct usb_driver lcd_driver = { 374 .owner = THIS_MODULE, 375 .name = "usblcd", 376 .probe = lcd_probe, 377 .disconnect = lcd_disconnect, 378 .id_table = id_table, 379 }; 380 381 static int __init usb_lcd_init(void) 382 { 383 int result; 384 385 result = usb_register(&lcd_driver); 386 if (result) 387 err("usb_register failed. Error number %d", result); 388 389 return result; 390 } 391 392 393 static void __exit usb_lcd_exit(void) 394 { 395 usb_deregister(&lcd_driver); 396 } 397 398 module_init(usb_lcd_init); 399 module_exit(usb_lcd_exit); 400 401 MODULE_AUTHOR("Georges Toth <g.toth@e-biz.lu>"); 402 MODULE_DESCRIPTION(DRIVER_VERSION); 403 MODULE_LICENSE("GPL"); 404