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 DEFINE_MUTEX(lcd_mutex); 33 static const struct usb_device_id id_table[] = { 34 { .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, }, 35 { }, 36 }; 37 MODULE_DEVICE_TABLE (usb, id_table); 38 39 static DEFINE_MUTEX(open_disc_mutex); 40 41 42 struct usb_lcd { 43 struct usb_device * udev; /* init: probe_lcd */ 44 struct usb_interface * interface; /* the interface for this device */ 45 unsigned char * bulk_in_buffer; /* the buffer to receive data */ 46 size_t bulk_in_size; /* the size of the receive buffer */ 47 __u8 bulk_in_endpointAddr; /* the address of the bulk in endpoint */ 48 __u8 bulk_out_endpointAddr; /* the address of the bulk out endpoint */ 49 struct kref kref; 50 struct semaphore limit_sem; /* to stop writes at full throttle from 51 * using up all RAM */ 52 struct usb_anchor submitted; /* URBs to wait for before suspend */ 53 }; 54 #define to_lcd_dev(d) container_of(d, struct usb_lcd, kref) 55 56 #define USB_LCD_CONCURRENT_WRITES 5 57 58 static struct usb_driver lcd_driver; 59 60 61 static void lcd_delete(struct kref *kref) 62 { 63 struct usb_lcd *dev = to_lcd_dev(kref); 64 65 usb_put_dev(dev->udev); 66 kfree (dev->bulk_in_buffer); 67 kfree (dev); 68 } 69 70 71 static int lcd_open(struct inode *inode, struct file *file) 72 { 73 struct usb_lcd *dev; 74 struct usb_interface *interface; 75 int subminor, r; 76 77 mutex_lock(&lcd_mutex); 78 subminor = iminor(inode); 79 80 interface = usb_find_interface(&lcd_driver, subminor); 81 if (!interface) { 82 mutex_unlock(&lcd_mutex); 83 err ("USBLCD: %s - error, can't find device for minor %d", 84 __func__, subminor); 85 return -ENODEV; 86 } 87 88 mutex_lock(&open_disc_mutex); 89 dev = usb_get_intfdata(interface); 90 if (!dev) { 91 mutex_unlock(&open_disc_mutex); 92 mutex_unlock(&lcd_mutex); 93 return -ENODEV; 94 } 95 96 /* increment our usage count for the device */ 97 kref_get(&dev->kref); 98 mutex_unlock(&open_disc_mutex); 99 100 /* grab a power reference */ 101 r = usb_autopm_get_interface(interface); 102 if (r < 0) { 103 kref_put(&dev->kref, lcd_delete); 104 mutex_unlock(&lcd_mutex); 105 return r; 106 } 107 108 /* save our object in the file's private structure */ 109 file->private_data = dev; 110 mutex_unlock(&lcd_mutex); 111 112 return 0; 113 } 114 115 static int lcd_release(struct inode *inode, struct file *file) 116 { 117 struct usb_lcd *dev; 118 119 dev = file->private_data; 120 if (dev == NULL) 121 return -ENODEV; 122 123 /* decrement the count on our device */ 124 usb_autopm_put_interface(dev->interface); 125 kref_put(&dev->kref, lcd_delete); 126 return 0; 127 } 128 129 static ssize_t lcd_read(struct file *file, char __user * buffer, size_t count, loff_t *ppos) 130 { 131 struct usb_lcd *dev; 132 int retval = 0; 133 int bytes_read; 134 135 dev = file->private_data; 136 137 /* do a blocking bulk read to get data from the device */ 138 retval = usb_bulk_msg(dev->udev, 139 usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr), 140 dev->bulk_in_buffer, 141 min(dev->bulk_in_size, count), 142 &bytes_read, 10000); 143 144 /* if the read was successful, copy the data to userspace */ 145 if (!retval) { 146 if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read)) 147 retval = -EFAULT; 148 else 149 retval = bytes_read; 150 } 151 152 return retval; 153 } 154 155 static long lcd_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 156 { 157 struct usb_lcd *dev; 158 u16 bcdDevice; 159 char buf[30]; 160 161 dev = file->private_data; 162 if (dev == NULL) 163 return -ENODEV; 164 165 switch (cmd) { 166 case IOCTL_GET_HARD_VERSION: 167 mutex_lock(&lcd_mutex); 168 bcdDevice = le16_to_cpu((dev->udev)->descriptor.bcdDevice); 169 sprintf(buf,"%1d%1d.%1d%1d", 170 (bcdDevice & 0xF000)>>12, 171 (bcdDevice & 0xF00)>>8, 172 (bcdDevice & 0xF0)>>4, 173 (bcdDevice & 0xF)); 174 mutex_unlock(&lcd_mutex); 175 if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0) 176 return -EFAULT; 177 break; 178 case IOCTL_GET_DRV_VERSION: 179 sprintf(buf,DRIVER_VERSION); 180 if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0) 181 return -EFAULT; 182 break; 183 default: 184 return -ENOTTY; 185 break; 186 } 187 188 return 0; 189 } 190 191 static void lcd_write_bulk_callback(struct urb *urb) 192 { 193 struct usb_lcd *dev; 194 int status = urb->status; 195 196 dev = urb->context; 197 198 /* sync/async unlink faults aren't errors */ 199 if (status && 200 !(status == -ENOENT || 201 status == -ECONNRESET || 202 status == -ESHUTDOWN)) { 203 dbg("USBLCD: %s - nonzero write bulk status received: %d", 204 __func__, status); 205 } 206 207 /* free up our allocated buffer */ 208 usb_free_coherent(urb->dev, urb->transfer_buffer_length, 209 urb->transfer_buffer, urb->transfer_dma); 210 up(&dev->limit_sem); 211 } 212 213 static ssize_t lcd_write(struct file *file, const char __user * user_buffer, size_t count, loff_t *ppos) 214 { 215 struct usb_lcd *dev; 216 int retval = 0, r; 217 struct urb *urb = NULL; 218 char *buf = NULL; 219 220 dev = file->private_data; 221 222 /* verify that we actually have some data to write */ 223 if (count == 0) 224 goto exit; 225 226 r = down_interruptible(&dev->limit_sem); 227 if (r < 0) 228 return -EINTR; 229 230 /* create a urb, and a buffer for it, and copy the data to the urb */ 231 urb = usb_alloc_urb(0, GFP_KERNEL); 232 if (!urb) { 233 retval = -ENOMEM; 234 goto err_no_buf; 235 } 236 237 buf = usb_alloc_coherent(dev->udev, count, GFP_KERNEL, &urb->transfer_dma); 238 if (!buf) { 239 retval = -ENOMEM; 240 goto error; 241 } 242 243 if (copy_from_user(buf, user_buffer, count)) { 244 retval = -EFAULT; 245 goto error; 246 } 247 248 /* initialize the urb properly */ 249 usb_fill_bulk_urb(urb, dev->udev, 250 usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr), 251 buf, count, lcd_write_bulk_callback, dev); 252 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 253 254 usb_anchor_urb(urb, &dev->submitted); 255 256 /* send the data out the bulk port */ 257 retval = usb_submit_urb(urb, GFP_KERNEL); 258 if (retval) { 259 err("USBLCD: %s - failed submitting write urb, error %d", __func__, retval); 260 goto error_unanchor; 261 } 262 263 /* release our reference to this urb, the USB core will eventually free it entirely */ 264 usb_free_urb(urb); 265 266 exit: 267 return count; 268 error_unanchor: 269 usb_unanchor_urb(urb); 270 error: 271 usb_free_coherent(dev->udev, count, buf, urb->transfer_dma); 272 usb_free_urb(urb); 273 err_no_buf: 274 up(&dev->limit_sem); 275 return retval; 276 } 277 278 static const struct file_operations lcd_fops = { 279 .owner = THIS_MODULE, 280 .read = lcd_read, 281 .write = lcd_write, 282 .open = lcd_open, 283 .unlocked_ioctl = lcd_ioctl, 284 .release = lcd_release, 285 }; 286 287 /* 288 * usb class driver info in order to get a minor number from the usb core, 289 * and to have the device registered with the driver core 290 */ 291 static struct usb_class_driver lcd_class = { 292 .name = "lcd%d", 293 .fops = &lcd_fops, 294 .minor_base = USBLCD_MINOR, 295 }; 296 297 static int lcd_probe(struct usb_interface *interface, const struct usb_device_id *id) 298 { 299 struct usb_lcd *dev = NULL; 300 struct usb_host_interface *iface_desc; 301 struct usb_endpoint_descriptor *endpoint; 302 size_t buffer_size; 303 int i; 304 int retval = -ENOMEM; 305 306 /* allocate memory for our device state and initialize it */ 307 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 308 if (dev == NULL) { 309 err("Out of memory"); 310 goto error; 311 } 312 kref_init(&dev->kref); 313 sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES); 314 init_usb_anchor(&dev->submitted); 315 316 dev->udev = usb_get_dev(interface_to_usbdev(interface)); 317 dev->interface = interface; 318 319 if (le16_to_cpu(dev->udev->descriptor.idProduct) != 0x0001) { 320 dev_warn(&interface->dev, "USBLCD model not supported.\n"); 321 retval = -ENODEV; 322 goto error; 323 } 324 325 /* set up the endpoint information */ 326 /* use only the first bulk-in and bulk-out endpoints */ 327 iface_desc = interface->cur_altsetting; 328 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { 329 endpoint = &iface_desc->endpoint[i].desc; 330 331 if (!dev->bulk_in_endpointAddr && 332 usb_endpoint_is_bulk_in(endpoint)) { 333 /* we found a bulk in endpoint */ 334 buffer_size = le16_to_cpu(endpoint->wMaxPacketSize); 335 dev->bulk_in_size = buffer_size; 336 dev->bulk_in_endpointAddr = endpoint->bEndpointAddress; 337 dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL); 338 if (!dev->bulk_in_buffer) { 339 err("Could not allocate bulk_in_buffer"); 340 goto error; 341 } 342 } 343 344 if (!dev->bulk_out_endpointAddr && 345 usb_endpoint_is_bulk_out(endpoint)) { 346 /* we found a bulk out endpoint */ 347 dev->bulk_out_endpointAddr = endpoint->bEndpointAddress; 348 } 349 } 350 if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) { 351 err("Could not find both bulk-in and bulk-out endpoints"); 352 goto error; 353 } 354 355 /* save our data pointer in this interface device */ 356 usb_set_intfdata(interface, dev); 357 358 /* we can register the device now, as it is ready */ 359 retval = usb_register_dev(interface, &lcd_class); 360 if (retval) { 361 /* something prevented us from registering this driver */ 362 err("Not able to get a minor for this device."); 363 usb_set_intfdata(interface, NULL); 364 goto error; 365 } 366 367 i = le16_to_cpu(dev->udev->descriptor.bcdDevice); 368 369 dev_info(&interface->dev, "USBLCD Version %1d%1d.%1d%1d found " 370 "at address %d\n", (i & 0xF000)>>12, (i & 0xF00)>>8, 371 (i & 0xF0)>>4,(i & 0xF), dev->udev->devnum); 372 373 /* let the user know what node this device is now attached to */ 374 dev_info(&interface->dev, "USB LCD device now attached to USBLCD-%d\n", 375 interface->minor); 376 return 0; 377 378 error: 379 if (dev) 380 kref_put(&dev->kref, lcd_delete); 381 return retval; 382 } 383 384 static void lcd_draw_down(struct usb_lcd *dev) 385 { 386 int time; 387 388 time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000); 389 if (!time) 390 usb_kill_anchored_urbs(&dev->submitted); 391 } 392 393 static int lcd_suspend(struct usb_interface *intf, pm_message_t message) 394 { 395 struct usb_lcd *dev = usb_get_intfdata(intf); 396 397 if (!dev) 398 return 0; 399 lcd_draw_down(dev); 400 return 0; 401 } 402 403 static int lcd_resume (struct usb_interface *intf) 404 { 405 return 0; 406 } 407 408 static void lcd_disconnect(struct usb_interface *interface) 409 { 410 struct usb_lcd *dev; 411 int minor = interface->minor; 412 413 mutex_lock(&open_disc_mutex); 414 dev = usb_get_intfdata(interface); 415 usb_set_intfdata(interface, NULL); 416 mutex_unlock(&open_disc_mutex); 417 418 /* give back our minor */ 419 usb_deregister_dev(interface, &lcd_class); 420 421 /* decrement our usage count */ 422 kref_put(&dev->kref, lcd_delete); 423 424 dev_info(&interface->dev, "USB LCD #%d now disconnected\n", minor); 425 } 426 427 static struct usb_driver lcd_driver = { 428 .name = "usblcd", 429 .probe = lcd_probe, 430 .disconnect = lcd_disconnect, 431 .suspend = lcd_suspend, 432 .resume = lcd_resume, 433 .id_table = id_table, 434 .supports_autosuspend = 1, 435 }; 436 437 static int __init usb_lcd_init(void) 438 { 439 int result; 440 441 result = usb_register(&lcd_driver); 442 if (result) 443 err("usb_register failed. Error number %d", result); 444 445 return result; 446 } 447 448 449 static void __exit usb_lcd_exit(void) 450 { 451 usb_deregister(&lcd_driver); 452 } 453 454 module_init(usb_lcd_init); 455 module_exit(usb_lcd_exit); 456 457 MODULE_AUTHOR("Georges Toth <g.toth@e-biz.lu>"); 458 MODULE_DESCRIPTION(DRIVER_VERSION); 459 MODULE_LICENSE("GPL"); 460