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