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 __func__, 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 long lcd_ioctl(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 lock_kernel(); 162 bcdDevice = le16_to_cpu((dev->udev)->descriptor.bcdDevice); 163 sprintf(buf,"%1d%1d.%1d%1d", 164 (bcdDevice & 0xF000)>>12, 165 (bcdDevice & 0xF00)>>8, 166 (bcdDevice & 0xF0)>>4, 167 (bcdDevice & 0xF)); 168 unlock_kernel(); 169 if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0) 170 return -EFAULT; 171 break; 172 case IOCTL_GET_DRV_VERSION: 173 sprintf(buf,DRIVER_VERSION); 174 if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0) 175 return -EFAULT; 176 break; 177 default: 178 return -ENOTTY; 179 break; 180 } 181 182 return 0; 183 } 184 185 static void lcd_write_bulk_callback(struct urb *urb) 186 { 187 struct usb_lcd *dev; 188 int status = urb->status; 189 190 dev = urb->context; 191 192 /* sync/async unlink faults aren't errors */ 193 if (status && 194 !(status == -ENOENT || 195 status == -ECONNRESET || 196 status == -ESHUTDOWN)) { 197 dbg("USBLCD: %s - nonzero write bulk status received: %d", 198 __func__, status); 199 } 200 201 /* free up our allocated buffer */ 202 usb_buffer_free(urb->dev, urb->transfer_buffer_length, 203 urb->transfer_buffer, urb->transfer_dma); 204 up(&dev->limit_sem); 205 } 206 207 static ssize_t lcd_write(struct file *file, const char __user * user_buffer, size_t count, loff_t *ppos) 208 { 209 struct usb_lcd *dev; 210 int retval = 0, r; 211 struct urb *urb = NULL; 212 char *buf = NULL; 213 214 dev = (struct usb_lcd *)file->private_data; 215 216 /* verify that we actually have some data to write */ 217 if (count == 0) 218 goto exit; 219 220 r = down_interruptible(&dev->limit_sem); 221 if (r < 0) 222 return -EINTR; 223 224 /* create a urb, and a buffer for it, and copy the data to the urb */ 225 urb = usb_alloc_urb(0, GFP_KERNEL); 226 if (!urb) { 227 retval = -ENOMEM; 228 goto err_no_buf; 229 } 230 231 buf = usb_buffer_alloc(dev->udev, count, GFP_KERNEL, &urb->transfer_dma); 232 if (!buf) { 233 retval = -ENOMEM; 234 goto error; 235 } 236 237 if (copy_from_user(buf, user_buffer, count)) { 238 retval = -EFAULT; 239 goto error; 240 } 241 242 /* initialize the urb properly */ 243 usb_fill_bulk_urb(urb, dev->udev, 244 usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr), 245 buf, count, lcd_write_bulk_callback, dev); 246 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 247 248 usb_anchor_urb(urb, &dev->submitted); 249 250 /* send the data out the bulk port */ 251 retval = usb_submit_urb(urb, GFP_KERNEL); 252 if (retval) { 253 err("USBLCD: %s - failed submitting write urb, error %d", __func__, retval); 254 goto error_unanchor; 255 } 256 257 /* release our reference to this urb, the USB core will eventually free it entirely */ 258 usb_free_urb(urb); 259 260 exit: 261 return count; 262 error_unanchor: 263 usb_unanchor_urb(urb); 264 error: 265 usb_buffer_free(dev->udev, count, buf, urb->transfer_dma); 266 usb_free_urb(urb); 267 err_no_buf: 268 up(&dev->limit_sem); 269 return retval; 270 } 271 272 static const struct file_operations lcd_fops = { 273 .owner = THIS_MODULE, 274 .read = lcd_read, 275 .write = lcd_write, 276 .open = lcd_open, 277 .unlocked_ioctl = lcd_ioctl, 278 .release = lcd_release, 279 }; 280 281 /* 282 * usb class driver info in order to get a minor number from the usb core, 283 * and to have the device registered with the driver core 284 */ 285 static struct usb_class_driver lcd_class = { 286 .name = "lcd%d", 287 .fops = &lcd_fops, 288 .minor_base = USBLCD_MINOR, 289 }; 290 291 static int lcd_probe(struct usb_interface *interface, const struct usb_device_id *id) 292 { 293 struct usb_lcd *dev = NULL; 294 struct usb_host_interface *iface_desc; 295 struct usb_endpoint_descriptor *endpoint; 296 size_t buffer_size; 297 int i; 298 int retval = -ENOMEM; 299 300 /* allocate memory for our device state and initialize it */ 301 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 302 if (dev == NULL) { 303 err("Out of memory"); 304 goto error; 305 } 306 kref_init(&dev->kref); 307 sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES); 308 init_usb_anchor(&dev->submitted); 309 310 dev->udev = usb_get_dev(interface_to_usbdev(interface)); 311 dev->interface = interface; 312 313 if (le16_to_cpu(dev->udev->descriptor.idProduct) != 0x0001) { 314 dev_warn(&interface->dev, "USBLCD model not supported.\n"); 315 return -ENODEV; 316 } 317 318 /* set up the endpoint information */ 319 /* use only the first bulk-in and bulk-out endpoints */ 320 iface_desc = interface->cur_altsetting; 321 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { 322 endpoint = &iface_desc->endpoint[i].desc; 323 324 if (!dev->bulk_in_endpointAddr && 325 usb_endpoint_is_bulk_in(endpoint)) { 326 /* we found a bulk in endpoint */ 327 buffer_size = le16_to_cpu(endpoint->wMaxPacketSize); 328 dev->bulk_in_size = buffer_size; 329 dev->bulk_in_endpointAddr = endpoint->bEndpointAddress; 330 dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL); 331 if (!dev->bulk_in_buffer) { 332 err("Could not allocate bulk_in_buffer"); 333 goto error; 334 } 335 } 336 337 if (!dev->bulk_out_endpointAddr && 338 usb_endpoint_is_bulk_out(endpoint)) { 339 /* we found a bulk out endpoint */ 340 dev->bulk_out_endpointAddr = endpoint->bEndpointAddress; 341 } 342 } 343 if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) { 344 err("Could not find both bulk-in and bulk-out endpoints"); 345 goto error; 346 } 347 348 /* save our data pointer in this interface device */ 349 usb_set_intfdata(interface, dev); 350 351 /* we can register the device now, as it is ready */ 352 retval = usb_register_dev(interface, &lcd_class); 353 if (retval) { 354 /* something prevented us from registering this driver */ 355 err("Not able to get a minor for this device."); 356 usb_set_intfdata(interface, NULL); 357 goto error; 358 } 359 360 i = le16_to_cpu(dev->udev->descriptor.bcdDevice); 361 362 dev_info(&interface->dev, "USBLCD Version %1d%1d.%1d%1d found " 363 "at address %d\n", (i & 0xF000)>>12, (i & 0xF00)>>8, 364 (i & 0xF0)>>4,(i & 0xF), dev->udev->devnum); 365 366 /* let the user know what node this device is now attached to */ 367 dev_info(&interface->dev, "USB LCD device now attached to USBLCD-%d\n", 368 interface->minor); 369 return 0; 370 371 error: 372 if (dev) 373 kref_put(&dev->kref, lcd_delete); 374 return retval; 375 } 376 377 static void lcd_draw_down(struct usb_lcd *dev) 378 { 379 int time; 380 381 time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000); 382 if (!time) 383 usb_kill_anchored_urbs(&dev->submitted); 384 } 385 386 static int lcd_suspend(struct usb_interface *intf, pm_message_t message) 387 { 388 struct usb_lcd *dev = usb_get_intfdata(intf); 389 390 if (!dev) 391 return 0; 392 lcd_draw_down(dev); 393 return 0; 394 } 395 396 static int lcd_resume (struct usb_interface *intf) 397 { 398 return 0; 399 } 400 401 static void lcd_disconnect(struct usb_interface *interface) 402 { 403 struct usb_lcd *dev; 404 int minor = interface->minor; 405 406 mutex_lock(&open_disc_mutex); 407 dev = usb_get_intfdata(interface); 408 usb_set_intfdata(interface, NULL); 409 mutex_unlock(&open_disc_mutex); 410 411 /* give back our minor */ 412 usb_deregister_dev(interface, &lcd_class); 413 414 /* decrement our usage count */ 415 kref_put(&dev->kref, lcd_delete); 416 417 dev_info(&interface->dev, "USB LCD #%d now disconnected\n", minor); 418 } 419 420 static struct usb_driver lcd_driver = { 421 .name = "usblcd", 422 .probe = lcd_probe, 423 .disconnect = lcd_disconnect, 424 .suspend = lcd_suspend, 425 .resume = lcd_resume, 426 .id_table = id_table, 427 .supports_autosuspend = 1, 428 }; 429 430 static int __init usb_lcd_init(void) 431 { 432 int result; 433 434 result = usb_register(&lcd_driver); 435 if (result) 436 err("usb_register failed. Error number %d", result); 437 438 return result; 439 } 440 441 442 static void __exit usb_lcd_exit(void) 443 { 444 usb_deregister(&lcd_driver); 445 } 446 447 module_init(usb_lcd_init); 448 module_exit(usb_lcd_exit); 449 450 MODULE_AUTHOR("Georges Toth <g.toth@e-biz.lu>"); 451 MODULE_DESCRIPTION(DRIVER_VERSION); 452 MODULE_LICENSE("GPL"); 453