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 <linux/mutex.h> 21 #include <asm/uaccess.h> 22 #include <linux/usb.h> 23 24 #define DRIVER_VERSION "USBLCD Driver Version 1.05" 25 26 #define USBLCD_MINOR 144 27 28 #define IOCTL_GET_HARD_VERSION 1 29 #define IOCTL_GET_DRV_VERSION 2 30 31 32 static struct usb_device_id id_table [] = { 33 { .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, }, 34 { }, 35 }; 36 MODULE_DEVICE_TABLE (usb, id_table); 37 38 static DEFINE_MUTEX(open_disc_mutex); 39 40 41 struct usb_lcd { 42 struct usb_device * udev; /* init: probe_lcd */ 43 struct usb_interface * interface; /* the interface for this device */ 44 unsigned char * bulk_in_buffer; /* the buffer to receive data */ 45 size_t bulk_in_size; /* the size of the receive buffer */ 46 __u8 bulk_in_endpointAddr; /* the address of the bulk in endpoint */ 47 __u8 bulk_out_endpointAddr; /* the address of the bulk out endpoint */ 48 struct kref kref; 49 struct semaphore limit_sem; /* to stop writes at full throttle from 50 * using up all RAM */ 51 struct usb_anchor submitted; /* URBs to wait for before suspend */ 52 }; 53 #define to_lcd_dev(d) container_of(d, struct usb_lcd, kref) 54 55 #define USB_LCD_CONCURRENT_WRITES 5 56 57 static struct usb_driver lcd_driver; 58 59 60 static void lcd_delete(struct kref *kref) 61 { 62 struct usb_lcd *dev = to_lcd_dev(kref); 63 64 usb_put_dev(dev->udev); 65 kfree (dev->bulk_in_buffer); 66 kfree (dev); 67 } 68 69 70 static int lcd_open(struct inode *inode, struct file *file) 71 { 72 struct usb_lcd *dev; 73 struct usb_interface *interface; 74 int subminor, r; 75 76 subminor = iminor(inode); 77 78 interface = usb_find_interface(&lcd_driver, subminor); 79 if (!interface) { 80 err ("USBLCD: %s - error, can't find device for minor %d", 81 __FUNCTION__, subminor); 82 return -ENODEV; 83 } 84 85 mutex_lock(&open_disc_mutex); 86 dev = usb_get_intfdata(interface); 87 if (!dev) { 88 mutex_unlock(&open_disc_mutex); 89 return -ENODEV; 90 } 91 92 /* increment our usage count for the device */ 93 kref_get(&dev->kref); 94 mutex_unlock(&open_disc_mutex); 95 96 /* grab a power reference */ 97 r = usb_autopm_get_interface(interface); 98 if (r < 0) { 99 kref_put(&dev->kref, lcd_delete); 100 return r; 101 } 102 103 /* save our object in the file's private structure */ 104 file->private_data = dev; 105 106 return 0; 107 } 108 109 static int lcd_release(struct inode *inode, struct file *file) 110 { 111 struct usb_lcd *dev; 112 113 dev = (struct usb_lcd *)file->private_data; 114 if (dev == NULL) 115 return -ENODEV; 116 117 /* decrement the count on our device */ 118 usb_autopm_put_interface(dev->interface); 119 kref_put(&dev->kref, lcd_delete); 120 return 0; 121 } 122 123 static ssize_t lcd_read(struct file *file, char __user * buffer, size_t count, loff_t *ppos) 124 { 125 struct usb_lcd *dev; 126 int retval = 0; 127 int bytes_read; 128 129 dev = (struct usb_lcd *)file->private_data; 130 131 /* do a blocking bulk read to get data from the device */ 132 retval = usb_bulk_msg(dev->udev, 133 usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr), 134 dev->bulk_in_buffer, 135 min(dev->bulk_in_size, count), 136 &bytes_read, 10000); 137 138 /* if the read was successful, copy the data to userspace */ 139 if (!retval) { 140 if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read)) 141 retval = -EFAULT; 142 else 143 retval = bytes_read; 144 } 145 146 return retval; 147 } 148 149 static int lcd_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) 150 { 151 struct usb_lcd *dev; 152 u16 bcdDevice; 153 char buf[30]; 154 155 dev = (struct usb_lcd *)file->private_data; 156 if (dev == NULL) 157 return -ENODEV; 158 159 switch (cmd) { 160 case IOCTL_GET_HARD_VERSION: 161 bcdDevice = le16_to_cpu((dev->udev)->descriptor.bcdDevice); 162 sprintf(buf,"%1d%1d.%1d%1d", 163 (bcdDevice & 0xF000)>>12, 164 (bcdDevice & 0xF00)>>8, 165 (bcdDevice & 0xF0)>>4, 166 (bcdDevice & 0xF)); 167 if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0) 168 return -EFAULT; 169 break; 170 case IOCTL_GET_DRV_VERSION: 171 sprintf(buf,DRIVER_VERSION); 172 if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0) 173 return -EFAULT; 174 break; 175 default: 176 return -ENOTTY; 177 break; 178 } 179 180 return 0; 181 } 182 183 static void lcd_write_bulk_callback(struct urb *urb) 184 { 185 struct usb_lcd *dev; 186 int status = urb->status; 187 188 dev = (struct usb_lcd *)urb->context; 189 190 /* sync/async unlink faults aren't errors */ 191 if (status && 192 !(status == -ENOENT || 193 status == -ECONNRESET || 194 status == -ESHUTDOWN)) { 195 dbg("USBLCD: %s - nonzero write bulk status received: %d", 196 __FUNCTION__, status); 197 } 198 199 /* free up our allocated buffer */ 200 usb_buffer_free(urb->dev, urb->transfer_buffer_length, 201 urb->transfer_buffer, urb->transfer_dma); 202 up(&dev->limit_sem); 203 } 204 205 static ssize_t lcd_write(struct file *file, const char __user * user_buffer, size_t count, loff_t *ppos) 206 { 207 struct usb_lcd *dev; 208 int retval = 0, r; 209 struct urb *urb = NULL; 210 char *buf = NULL; 211 212 dev = (struct usb_lcd *)file->private_data; 213 214 /* verify that we actually have some data to write */ 215 if (count == 0) 216 goto exit; 217 218 r = down_interruptible(&dev->limit_sem); 219 if (r < 0) 220 return -EINTR; 221 222 /* create a urb, and a buffer for it, and copy the data to the urb */ 223 urb = usb_alloc_urb(0, GFP_KERNEL); 224 if (!urb) { 225 retval = -ENOMEM; 226 goto err_no_buf; 227 } 228 229 buf = usb_buffer_alloc(dev->udev, count, GFP_KERNEL, &urb->transfer_dma); 230 if (!buf) { 231 retval = -ENOMEM; 232 goto error; 233 } 234 235 if (copy_from_user(buf, user_buffer, count)) { 236 retval = -EFAULT; 237 goto error; 238 } 239 240 /* initialize the urb properly */ 241 usb_fill_bulk_urb(urb, dev->udev, 242 usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr), 243 buf, count, lcd_write_bulk_callback, dev); 244 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 245 246 usb_anchor_urb(urb, &dev->submitted); 247 248 /* send the data out the bulk port */ 249 retval = usb_submit_urb(urb, GFP_KERNEL); 250 if (retval) { 251 err("USBLCD: %s - failed submitting write urb, error %d", __FUNCTION__, retval); 252 goto error_unanchor; 253 } 254 255 /* release our reference to this urb, the USB core will eventually free it entirely */ 256 usb_free_urb(urb); 257 258 exit: 259 return count; 260 error_unanchor: 261 usb_unanchor_urb(urb); 262 error: 263 usb_buffer_free(dev->udev, count, buf, urb->transfer_dma); 264 usb_free_urb(urb); 265 err_no_buf: 266 up(&dev->limit_sem); 267 return retval; 268 } 269 270 static const struct file_operations lcd_fops = { 271 .owner = THIS_MODULE, 272 .read = lcd_read, 273 .write = lcd_write, 274 .open = lcd_open, 275 .ioctl = lcd_ioctl, 276 .release = lcd_release, 277 }; 278 279 /* 280 * usb class driver info in order to get a minor number from the usb core, 281 * and to have the device registered with the driver core 282 */ 283 static struct usb_class_driver lcd_class = { 284 .name = "lcd%d", 285 .fops = &lcd_fops, 286 .minor_base = USBLCD_MINOR, 287 }; 288 289 static int lcd_probe(struct usb_interface *interface, const struct usb_device_id *id) 290 { 291 struct usb_lcd *dev = NULL; 292 struct usb_host_interface *iface_desc; 293 struct usb_endpoint_descriptor *endpoint; 294 size_t buffer_size; 295 int i; 296 int retval = -ENOMEM; 297 298 /* allocate memory for our device state and initialize it */ 299 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 300 if (dev == NULL) { 301 err("Out of memory"); 302 goto error; 303 } 304 kref_init(&dev->kref); 305 sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES); 306 init_usb_anchor(&dev->submitted); 307 308 dev->udev = usb_get_dev(interface_to_usbdev(interface)); 309 dev->interface = interface; 310 311 if (le16_to_cpu(dev->udev->descriptor.idProduct) != 0x0001) { 312 warn(KERN_INFO "USBLCD model not supported."); 313 return -ENODEV; 314 } 315 316 /* set up the endpoint information */ 317 /* use only the first bulk-in and bulk-out endpoints */ 318 iface_desc = interface->cur_altsetting; 319 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { 320 endpoint = &iface_desc->endpoint[i].desc; 321 322 if (!dev->bulk_in_endpointAddr && 323 usb_endpoint_is_bulk_in(endpoint)) { 324 /* we found a bulk in endpoint */ 325 buffer_size = le16_to_cpu(endpoint->wMaxPacketSize); 326 dev->bulk_in_size = buffer_size; 327 dev->bulk_in_endpointAddr = endpoint->bEndpointAddress; 328 dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL); 329 if (!dev->bulk_in_buffer) { 330 err("Could not allocate bulk_in_buffer"); 331 goto error; 332 } 333 } 334 335 if (!dev->bulk_out_endpointAddr && 336 usb_endpoint_is_bulk_out(endpoint)) { 337 /* we found a bulk out endpoint */ 338 dev->bulk_out_endpointAddr = endpoint->bEndpointAddress; 339 } 340 } 341 if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) { 342 err("Could not find both bulk-in and bulk-out endpoints"); 343 goto error; 344 } 345 346 /* save our data pointer in this interface device */ 347 usb_set_intfdata(interface, dev); 348 349 /* we can register the device now, as it is ready */ 350 retval = usb_register_dev(interface, &lcd_class); 351 if (retval) { 352 /* something prevented us from registering this driver */ 353 err("Not able to get a minor for this device."); 354 usb_set_intfdata(interface, NULL); 355 goto error; 356 } 357 358 i = le16_to_cpu(dev->udev->descriptor.bcdDevice); 359 360 info("USBLCD Version %1d%1d.%1d%1d found at address %d", 361 (i & 0xF000)>>12,(i & 0xF00)>>8,(i & 0xF0)>>4,(i & 0xF), 362 dev->udev->devnum); 363 364 /* let the user know what node this device is now attached to */ 365 info("USB LCD device now attached to USBLCD-%d", interface->minor); 366 return 0; 367 368 error: 369 if (dev) 370 kref_put(&dev->kref, lcd_delete); 371 return retval; 372 } 373 374 static void lcd_draw_down(struct usb_lcd *dev) 375 { 376 int time; 377 378 time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000); 379 if (!time) 380 usb_kill_anchored_urbs(&dev->submitted); 381 } 382 383 static int lcd_suspend(struct usb_interface *intf, pm_message_t message) 384 { 385 struct usb_lcd *dev = usb_get_intfdata(intf); 386 387 if (!dev) 388 return 0; 389 lcd_draw_down(dev); 390 return 0; 391 } 392 393 static int lcd_resume (struct usb_interface *intf) 394 { 395 return 0; 396 } 397 398 static void lcd_disconnect(struct usb_interface *interface) 399 { 400 struct usb_lcd *dev; 401 int minor = interface->minor; 402 403 mutex_lock(&open_disc_mutex); 404 dev = usb_get_intfdata(interface); 405 usb_set_intfdata(interface, NULL); 406 mutex_unlock(&open_disc_mutex); 407 408 /* give back our minor */ 409 usb_deregister_dev(interface, &lcd_class); 410 411 /* decrement our usage count */ 412 kref_put(&dev->kref, lcd_delete); 413 414 info("USB LCD #%d now disconnected", minor); 415 } 416 417 static struct usb_driver lcd_driver = { 418 .name = "usblcd", 419 .probe = lcd_probe, 420 .disconnect = lcd_disconnect, 421 .suspend = lcd_suspend, 422 .resume = lcd_resume, 423 .id_table = id_table, 424 .supports_autosuspend = 1, 425 }; 426 427 static int __init usb_lcd_init(void) 428 { 429 int result; 430 431 result = usb_register(&lcd_driver); 432 if (result) 433 err("usb_register failed. Error number %d", result); 434 435 return result; 436 } 437 438 439 static void __exit usb_lcd_exit(void) 440 { 441 usb_deregister(&lcd_driver); 442 } 443 444 module_init(usb_lcd_init); 445 module_exit(usb_lcd_exit); 446 447 MODULE_AUTHOR("Georges Toth <g.toth@e-biz.lu>"); 448 MODULE_DESCRIPTION(DRIVER_VERSION); 449 MODULE_LICENSE("GPL"); 450