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 static DEFINE_MUTEX(usb_lcd_open_mutex); 51 52 53 static void lcd_delete(struct kref *kref) 54 { 55 struct usb_lcd *dev = to_lcd_dev(kref); 56 57 usb_put_dev(dev->udev); 58 kfree (dev->bulk_in_buffer); 59 kfree (dev); 60 } 61 62 63 static int lcd_open(struct inode *inode, struct file *file) 64 { 65 struct usb_lcd *dev; 66 struct usb_interface *interface; 67 int subminor; 68 int retval = 0; 69 70 subminor = iminor(inode); 71 72 mutex_lock(&usb_lcd_open_mutex); 73 interface = usb_find_interface(&lcd_driver, subminor); 74 if (!interface) { 75 err ("USBLCD: %s - error, can't find device for minor %d", 76 __FUNCTION__, subminor); 77 retval = -ENODEV; 78 goto exit; 79 } 80 81 dev = usb_get_intfdata(interface); 82 if (!dev) { 83 retval = -ENODEV; 84 goto exit; 85 } 86 87 /* increment our usage count for the device */ 88 kref_get(&dev->kref); 89 90 /* save our object in the file's private structure */ 91 file->private_data = dev; 92 93 exit: 94 mutex_unlock(&usb_lcd_open_mutex); 95 return retval; 96 } 97 98 static int lcd_release(struct inode *inode, struct file *file) 99 { 100 struct usb_lcd *dev; 101 102 dev = (struct usb_lcd *)file->private_data; 103 if (dev == NULL) 104 return -ENODEV; 105 106 /* decrement the count on our device */ 107 kref_put(&dev->kref, lcd_delete); 108 return 0; 109 } 110 111 static ssize_t lcd_read(struct file *file, char __user * buffer, size_t count, loff_t *ppos) 112 { 113 struct usb_lcd *dev; 114 int retval = 0; 115 int bytes_read; 116 117 dev = (struct usb_lcd *)file->private_data; 118 119 /* do a blocking bulk read to get data from the device */ 120 retval = usb_bulk_msg(dev->udev, 121 usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr), 122 dev->bulk_in_buffer, 123 min(dev->bulk_in_size, count), 124 &bytes_read, 10000); 125 126 /* if the read was successful, copy the data to userspace */ 127 if (!retval) { 128 if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read)) 129 retval = -EFAULT; 130 else 131 retval = bytes_read; 132 } 133 134 return retval; 135 } 136 137 static int lcd_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) 138 { 139 struct usb_lcd *dev; 140 u16 bcdDevice; 141 char buf[30]; 142 143 dev = (struct usb_lcd *)file->private_data; 144 if (dev == NULL) 145 return -ENODEV; 146 147 switch (cmd) { 148 case IOCTL_GET_HARD_VERSION: 149 bcdDevice = le16_to_cpu((dev->udev)->descriptor.bcdDevice); 150 sprintf(buf,"%1d%1d.%1d%1d", 151 (bcdDevice & 0xF000)>>12, 152 (bcdDevice & 0xF00)>>8, 153 (bcdDevice & 0xF0)>>4, 154 (bcdDevice & 0xF)); 155 if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0) 156 return -EFAULT; 157 break; 158 case IOCTL_GET_DRV_VERSION: 159 sprintf(buf,DRIVER_VERSION); 160 if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0) 161 return -EFAULT; 162 break; 163 default: 164 return -ENOTTY; 165 break; 166 } 167 168 return 0; 169 } 170 171 static void lcd_write_bulk_callback(struct urb *urb) 172 { 173 struct usb_lcd *dev; 174 175 dev = (struct usb_lcd *)urb->context; 176 177 /* sync/async unlink faults aren't errors */ 178 if (urb->status && 179 !(urb->status == -ENOENT || 180 urb->status == -ECONNRESET || 181 urb->status == -ESHUTDOWN)) { 182 dbg("USBLCD: %s - nonzero write bulk status received: %d", 183 __FUNCTION__, urb->status); 184 } 185 186 /* free up our allocated buffer */ 187 usb_buffer_free(urb->dev, urb->transfer_buffer_length, 188 urb->transfer_buffer, urb->transfer_dma); 189 } 190 191 static ssize_t lcd_write(struct file *file, const char __user * user_buffer, size_t count, loff_t *ppos) 192 { 193 struct usb_lcd *dev; 194 int retval = 0; 195 struct urb *urb = NULL; 196 char *buf = NULL; 197 198 dev = (struct usb_lcd *)file->private_data; 199 200 /* verify that we actually have some data to write */ 201 if (count == 0) 202 goto exit; 203 204 /* create a urb, and a buffer for it, and copy the data to the urb */ 205 urb = usb_alloc_urb(0, GFP_KERNEL); 206 if (!urb) 207 return -ENOMEM; 208 209 buf = usb_buffer_alloc(dev->udev, count, GFP_KERNEL, &urb->transfer_dma); 210 if (!buf) { 211 retval = -ENOMEM; 212 goto error; 213 } 214 215 if (copy_from_user(buf, user_buffer, count)) { 216 retval = -EFAULT; 217 goto error; 218 } 219 220 /* initialize the urb properly */ 221 usb_fill_bulk_urb(urb, dev->udev, 222 usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr), 223 buf, count, lcd_write_bulk_callback, dev); 224 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 225 226 /* send the data out the bulk port */ 227 retval = usb_submit_urb(urb, GFP_KERNEL); 228 if (retval) { 229 err("USBLCD: %s - failed submitting write urb, error %d", __FUNCTION__, retval); 230 goto error; 231 } 232 233 /* release our reference to this urb, the USB core will eventually free it entirely */ 234 usb_free_urb(urb); 235 236 exit: 237 return count; 238 239 error: 240 usb_buffer_free(dev->udev, count, buf, urb->transfer_dma); 241 usb_free_urb(urb); 242 return retval; 243 } 244 245 static const struct file_operations lcd_fops = { 246 .owner = THIS_MODULE, 247 .read = lcd_read, 248 .write = lcd_write, 249 .open = lcd_open, 250 .ioctl = lcd_ioctl, 251 .release = lcd_release, 252 }; 253 254 /* 255 * usb class driver info in order to get a minor number from the usb core, 256 * and to have the device registered with the driver core 257 */ 258 static struct usb_class_driver lcd_class = { 259 .name = "lcd%d", 260 .fops = &lcd_fops, 261 .minor_base = USBLCD_MINOR, 262 }; 263 264 static int lcd_probe(struct usb_interface *interface, const struct usb_device_id *id) 265 { 266 struct usb_lcd *dev = NULL; 267 struct usb_host_interface *iface_desc; 268 struct usb_endpoint_descriptor *endpoint; 269 size_t buffer_size; 270 int i; 271 int retval = -ENOMEM; 272 273 /* allocate memory for our device state and initialize it */ 274 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 275 if (dev == NULL) { 276 err("Out of memory"); 277 goto error; 278 } 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 usb_endpoint_is_bulk_in(endpoint)) { 297 /* we found a bulk in endpoint */ 298 buffer_size = le16_to_cpu(endpoint->wMaxPacketSize); 299 dev->bulk_in_size = buffer_size; 300 dev->bulk_in_endpointAddr = endpoint->bEndpointAddress; 301 dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL); 302 if (!dev->bulk_in_buffer) { 303 err("Could not allocate bulk_in_buffer"); 304 goto error; 305 } 306 } 307 308 if (!dev->bulk_out_endpointAddr && 309 usb_endpoint_is_bulk_out(endpoint)) { 310 /* we found a bulk out endpoint */ 311 dev->bulk_out_endpointAddr = endpoint->bEndpointAddress; 312 } 313 } 314 if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) { 315 err("Could not find both bulk-in and bulk-out endpoints"); 316 goto error; 317 } 318 319 /* save our data pointer in this interface device */ 320 usb_set_intfdata(interface, dev); 321 322 /* we can register the device now, as it is ready */ 323 retval = usb_register_dev(interface, &lcd_class); 324 if (retval) { 325 /* something prevented us from registering this driver */ 326 err("Not able to get a minor for this device."); 327 usb_set_intfdata(interface, NULL); 328 goto error; 329 } 330 331 i = le16_to_cpu(dev->udev->descriptor.bcdDevice); 332 333 info("USBLCD Version %1d%1d.%1d%1d found at address %d", 334 (i & 0xF000)>>12,(i & 0xF00)>>8,(i & 0xF0)>>4,(i & 0xF), 335 dev->udev->devnum); 336 337 /* let the user know what node this device is now attached to */ 338 info("USB LCD device now attached to USBLCD-%d", interface->minor); 339 return 0; 340 341 error: 342 if (dev) 343 kref_put(&dev->kref, lcd_delete); 344 return retval; 345 } 346 347 static void lcd_disconnect(struct usb_interface *interface) 348 { 349 struct usb_lcd *dev; 350 int minor = interface->minor; 351 352 /* prevent skel_open() from racing skel_disconnect() */ 353 mutex_lock(&usb_lcd_open_mutex); 354 355 dev = usb_get_intfdata(interface); 356 usb_set_intfdata(interface, NULL); 357 358 /* give back our minor */ 359 usb_deregister_dev(interface, &lcd_class); 360 361 mutex_unlock(&usb_lcd_open_mutex); 362 363 /* decrement our usage count */ 364 kref_put(&dev->kref, lcd_delete); 365 366 info("USB LCD #%d now disconnected", minor); 367 } 368 369 static struct usb_driver lcd_driver = { 370 .name = "usblcd", 371 .probe = lcd_probe, 372 .disconnect = lcd_disconnect, 373 .id_table = id_table, 374 }; 375 376 static int __init usb_lcd_init(void) 377 { 378 int result; 379 380 result = usb_register(&lcd_driver); 381 if (result) 382 err("usb_register failed. Error number %d", result); 383 384 return result; 385 } 386 387 388 static void __exit usb_lcd_exit(void) 389 { 390 usb_deregister(&lcd_driver); 391 } 392 393 module_init(usb_lcd_init); 394 module_exit(usb_lcd_exit); 395 396 MODULE_AUTHOR("Georges Toth <g.toth@e-biz.lu>"); 397 MODULE_DESCRIPTION(DRIVER_VERSION); 398 MODULE_LICENSE("GPL"); 399