drivers/usb/serial/opticon.c

   1 /*
   2  * Opticon USB barcode to serial driver
   3  *
   4  * Copyright (C) 2008 - 2009 Greg Kroah-Hartman <gregkh@suse.de>
   5  * Copyright (C) 2008 - 2009 Novell Inc.
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License version
   9  *      2 as published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/init.h>
  14 #include <linux/tty.h>
  15 #include <linux/tty_driver.h>
  16 #include <linux/slab.h>
  17 #include <linux/tty_flip.h>
  18 #include <linux/serial.h>
  19 #include <linux/module.h>
  20 #include <linux/usb.h>
  21 #include <linux/usb/serial.h>
  22 #include <linux/uaccess.h>
  23
  24 static int debug;
  25
  26 static const struct usb_device_id id_table[] = {
  27         { USB_DEVICE(0x065a, 0x0009) },
  28         { },
  29 };
  30 MODULE_DEVICE_TABLE(usb, id_table);
  31
  32 /* This structure holds all of the individual device information */
  33 struct opticon_private {
  34         struct usb_device *udev;
  35         struct usb_serial *serial;
  36         struct usb_serial_port *port;
  37         unsigned char *bulk_in_buffer;
  38         struct urb *bulk_read_urb;
  39         int buffer_size;
  40         u8 bulk_address;
  41         spinlock_t lock;        /* protects the following flags */
  42         bool throttled;
  43         bool actually_throttled;
  44         bool rts;
  45         int outstanding_urbs;
  46 };
  47
  48 /* max number of write urbs in flight */
  49 #define URB_UPPER_LIMIT 4
  50
  51 static void opticon_bulk_callback(struct urb *urb)
  52 {
  53         struct opticon_private *priv = urb->context;
  54         unsigned char *data = urb->transfer_buffer;
  55         struct usb_serial_port *port = priv->port;
  56         int status = urb->status;
  57         struct tty_struct *tty;
  58         int result;
  59         int data_length;
  60
  61         dbg("%s - port %d", __func__, port->number);
  62
  63         switch (status) {
  64         case 0:
  65                 /* success */
  66                 break;
  67         case -ECONNRESET:
  68         case -ENOENT:
  69         case -ESHUTDOWN:
  70                 /* this urb is terminated, clean up */
  71                 dbg("%s - urb shutting down with status: %d",
  72                     __func__, status);
  73                 return;
  74         default:
  75                 dbg("%s - nonzero urb status received: %d",
  76                     __func__, status);
  77                 goto exit;
  78         }
  79
  80         usb_serial_debug_data(debug, &port->dev, __func__, urb->actual_length,
  81                               data);
  82
  83         if (urb->actual_length > 2) {
  84                 data_length = urb->actual_length - 2;
  85
  86                 /*
  87                  * Data from the device comes with a 2 byte header:
  88                  *
  89                  * <0x00><0x00>data...
  90                  *      This is real data to be sent to the tty layer
  91                  * <0x00><0x01)level
  92                  *      This is a RTS level change, the third byte is the RTS
  93                  *      value (0 for low, 1 for high).
  94                  */
  95                 if ((data[0] == 0x00) && (data[1] == 0x00)) {
  96                         /* real data, send it to the tty layer */
  97                         tty = tty_port_tty_get(&port->port);
  98                         if (tty) {
  99                                 tty_insert_flip_string(tty, data,
 100                                                                data_length);
 101                                 tty_flip_buffer_push(tty);
 102                                 tty_kref_put(tty);
 103                         }
 104                 } else {
 105                         if ((data[0] == 0x00) && (data[1] == 0x01)) {
 106                                 if (data[2] == 0x00)
 107                                         priv->rts = false;
 108                                 else
 109                                         priv->rts = true;
 110                         } else {
 111                         dev_dbg(&priv->udev->dev,
 112                                 "Unknown data packet received from the device:"
 113                                 " %2x %2x\n",
 114                                 data[0], data[1]);
 115                         }
 116                 }
 117         } else {
 118                 dev_dbg(&priv->udev->dev,
 119                         "Improper amount of data received from the device, "
 120                         "%d bytes", urb->actual_length);
 121         }
 122
 123 exit:
 124         spin_lock(&priv->lock);
 125
 126         /* Continue trying to always read if we should */
 127         if (!priv->throttled) {
 128                 usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
 129                                   usb_rcvbulkpipe(priv->udev,
 130                                                   priv->bulk_address),
 131                                   priv->bulk_in_buffer, priv->buffer_size,
 132                                   opticon_bulk_callback, priv);
 133                 result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
 134                 if (result)
 135                         dev_err(&port->dev,
 136                             "%s - failed resubmitting read urb, error %d\n",
 137                                                         __func__, result);
 138         } else
 139                 priv->actually_throttled = true;
 140         spin_unlock(&priv->lock);
 141 }
 142
 143 static int opticon_open(struct tty_struct *tty, struct usb_serial_port *port)
 144 {
 145         struct opticon_private *priv = usb_get_serial_data(port->serial);
 146         unsigned long flags;
 147         int result = 0;
 148
 149         dbg("%s - port %d", __func__, port->number);
 150
 151         spin_lock_irqsave(&priv->lock, flags);
 152         priv->throttled = false;
 153         priv->actually_throttled = false;
 154         priv->port = port;
 155         spin_unlock_irqrestore(&priv->lock, flags);
 156
 157         /* Start reading from the device */
 158         usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
 159                           usb_rcvbulkpipe(priv->udev,
 160                                           priv->bulk_address),
 161                           priv->bulk_in_buffer, priv->buffer_size,
 162                           opticon_bulk_callback, priv);
 163         result = usb_submit_urb(priv->bulk_read_urb, GFP_KERNEL);
 164         if (result)
 165                 dev_err(&port->dev,
 166                         "%s - failed resubmitting read urb, error %d\n",
 167                         __func__, result);
 168         return result;
 169 }
 170
 171 static void opticon_close(struct usb_serial_port *port)
 172 {
 173         struct opticon_private *priv = usb_get_serial_data(port->serial);
 174
 175         dbg("%s - port %d", __func__, port->number);
 176
 177         /* shutdown our urbs */
 178         usb_kill_urb(priv->bulk_read_urb);
 179 }
 180
 181 static void opticon_write_bulk_callback(struct urb *urb)
 182 {
 183         struct opticon_private *priv = urb->context;
 184         int status = urb->status;
 185         unsigned long flags;
 186
 187         /* free up the transfer buffer, as usb_free_urb() does not do this */
 188         kfree(urb->transfer_buffer);
 189
 190         if (status)
 191                 dbg("%s - nonzero write bulk status received: %d",
 192                     __func__, status);
 193
 194         spin_lock_irqsave(&priv->lock, flags);
 195         --priv->outstanding_urbs;
 196         spin_unlock_irqrestore(&priv->lock, flags);
 197
 198         usb_serial_port_softint(priv->port);
 199 }
 200
 201 static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
 202                          const unsigned char *buf, int count)
 203 {
 204         struct opticon_private *priv = usb_get_serial_data(port->serial);
 205         struct usb_serial *serial = port->serial;
 206         struct urb *urb;
 207         unsigned char *buffer;
 208         unsigned long flags;
 209         int status;
 210
 211         dbg("%s - port %d", __func__, port->number);
 212
 213         spin_lock_irqsave(&priv->lock, flags);
 214         if (priv->outstanding_urbs > URB_UPPER_LIMIT) {
 215                 spin_unlock_irqrestore(&priv->lock, flags);
 216                 dbg("%s - write limit hit", __func__);
 217                 return 0;
 218         }
 219         priv->outstanding_urbs++;
 220         spin_unlock_irqrestore(&priv->lock, flags);
 221
 222         buffer = kmalloc(count, GFP_ATOMIC);
 223         if (!buffer) {
 224                 dev_err(&port->dev, "out of memory\n");
 225                 count = -ENOMEM;
 226                 goto error_no_buffer;
 227         }
 228
 229         urb = usb_alloc_urb(0, GFP_ATOMIC);
 230         if (!urb) {
 231                 dev_err(&port->dev, "no more free urbs\n");
 232                 count = -ENOMEM;
 233                 goto error_no_urb;
 234         }
 235
 236         memcpy(buffer, buf, count);
 237
 238         usb_serial_debug_data(debug, &port->dev, __func__, count, buffer);
 239
 240         usb_fill_bulk_urb(urb, serial->dev,
 241                           usb_sndbulkpipe(serial->dev,
 242                                           port->bulk_out_endpointAddress),
 243                           buffer, count, opticon_write_bulk_callback, priv);
 244
 245         /* send it down the pipe */
 246         status = usb_submit_urb(urb, GFP_ATOMIC);
 247         if (status) {
 248                 dev_err(&port->dev,
 249                    "%s - usb_submit_urb(write bulk) failed with status = %d\n",
 250                                                         __func__, status);
 251                 count = status;
 252                 goto error;
 253         }
 254
 255         /* we are done with this urb, so let the host driver
 256          * really free it when it is finished with it */
 257         usb_free_urb(urb);
 258
 259         return count;
 260 error:
 261         usb_free_urb(urb);
 262 error_no_urb:
 263         kfree(buffer);
 264 error_no_buffer:
 265         spin_lock_irqsave(&priv->lock, flags);
 266         --priv->outstanding_urbs;
 267         spin_unlock_irqrestore(&priv->lock, flags);
 268         return count;
 269 }
 270
 271 static int opticon_write_room(struct tty_struct *tty)
 272 {
 273         struct usb_serial_port *port = tty->driver_data;
 274         struct opticon_private *priv = usb_get_serial_data(port->serial);
 275         unsigned long flags;
 276
 277         dbg("%s - port %d", __func__, port->number);
 278
 279         /*
 280          * We really can take almost anything the user throws at us
 281          * but let's pick a nice big number to tell the tty
 282          * layer that we have lots of free space, unless we don't.
 283          */
 284         spin_lock_irqsave(&priv->lock, flags);
 285         if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) {
 286                 spin_unlock_irqrestore(&priv->lock, flags);
 287                 dbg("%s - write limit hit", __func__);
 288                 return 0;
 289         }
 290         spin_unlock_irqrestore(&priv->lock, flags);
 291
 292         return 2048;
 293 }
 294
 295 static void opticon_throttle(struct tty_struct *tty)
 296 {
 297         struct usb_serial_port *port = tty->driver_data;
 298         struct opticon_private *priv = usb_get_serial_data(port->serial);
 299         unsigned long flags;
 300
 301         dbg("%s - port %d", __func__, port->number);
 302         spin_lock_irqsave(&priv->lock, flags);
 303         priv->throttled = true;
 304         spin_unlock_irqrestore(&priv->lock, flags);
 305 }
 306
 307
 308 static void opticon_unthrottle(struct tty_struct *tty)
 309 {
 310         struct usb_serial_port *port = tty->driver_data;
 311         struct opticon_private *priv = usb_get_serial_data(port->serial);
 312         unsigned long flags;
 313         int result, was_throttled;
 314
 315         dbg("%s - port %d", __func__, port->number);
 316
 317         spin_lock_irqsave(&priv->lock, flags);
 318         priv->throttled = false;
 319         was_throttled = priv->actually_throttled;
 320         priv->actually_throttled = false;
 321         spin_unlock_irqrestore(&priv->lock, flags);
 322
 323         priv->bulk_read_urb->dev = port->serial->dev;
 324         if (was_throttled) {
 325                 result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC);
 326                 if (result)
 327                         dev_err(&port->dev,
 328                                 "%s - failed submitting read urb, error %d\n",
 329                                                         __func__, result);
 330         }
 331 }
 332
 333 static int opticon_tiocmget(struct tty_struct *tty, struct file *file)
 334 {
 335         struct usb_serial_port *port = tty->driver_data;
 336         struct opticon_private *priv = usb_get_serial_data(port->serial);
 337         unsigned long flags;
 338         int result = 0;
 339
 340         dbg("%s - port %d", __func__, port->number);
 341
 342         spin_lock_irqsave(&priv->lock, flags);
 343         if (priv->rts)
 344                 result = TIOCM_RTS;
 345         spin_unlock_irqrestore(&priv->lock, flags);
 346
 347         dbg("%s - %x", __func__, result);
 348         return result;
 349 }
 350
 351 static int get_serial_info(struct opticon_private *priv,
 352                            struct serial_struct __user *serial)
 353 {
 354         struct serial_struct tmp;
 355
 356         if (!serial)
 357                 return -EFAULT;
 358
 359         memset(&tmp, 0x00, sizeof(tmp));
 360
 361         /* fake emulate a 16550 uart to make userspace code happy */
 362         tmp.type                = PORT_16550A;
 363         tmp.line                = priv->serial->minor;
 364         tmp.port                = 0;
 365         tmp.irq                 = 0;
 366         tmp.flags               = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
 367         tmp.xmit_fifo_size      = 1024;
 368         tmp.baud_base           = 9600;
 369         tmp.close_delay         = 5*HZ;
 370         tmp.closing_wait        = 30*HZ;
 371
 372         if (copy_to_user(serial, &tmp, sizeof(*serial)))
 373                 return -EFAULT;
 374         return 0;
 375 }
 376
 377 static int opticon_ioctl(struct tty_struct *tty, struct file *file,
 378                          unsigned int cmd, unsigned long arg)
 379 {
 380         struct usb_serial_port *port = tty->driver_data;
 381         struct opticon_private *priv = usb_get_serial_data(port->serial);
 382
 383         dbg("%s - port %d, cmd = 0x%x", __func__, port->number, cmd);
 384
 385         switch (cmd) {
 386         case TIOCGSERIAL:
 387                 return get_serial_info(priv,
 388                                        (struct serial_struct __user *)arg);
 389         }
 390
 391         return -ENOIOCTLCMD;
 392 }
 393
 394 static int opticon_startup(struct usb_serial *serial)
 395 {
 396         struct opticon_private *priv;
 397         struct usb_host_interface *intf;
 398         int i;
 399         int retval = -ENOMEM;
 400         bool bulk_in_found = false;
 401
 402         /* create our private serial structure */
 403         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 404         if (priv == NULL) {
 405                 dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__);
 406                 return -ENOMEM;
 407         }
 408         spin_lock_init(&priv->lock);
 409         priv->serial = serial;
 410         priv->port = serial->port[0];
 411         priv->udev = serial->dev;
 412
 413         /* find our bulk endpoint */
 414         intf = serial->interface->altsetting;
 415         for (i = 0; i < intf->desc.bNumEndpoints; ++i) {
 416                 struct usb_endpoint_descriptor *endpoint;
 417
 418                 endpoint = &intf->endpoint[i].desc;
 419                 if (!usb_endpoint_is_bulk_in(endpoint))
 420                         continue;
 421
 422                 priv->bulk_read_urb = usb_alloc_urb(0, GFP_KERNEL);
 423                 if (!priv->bulk_read_urb) {
 424                         dev_err(&priv->udev->dev, "out of memory\n");
 425                         goto error;
 426                 }
 427
 428                 priv->buffer_size = le16_to_cpu(endpoint->wMaxPacketSize) * 2;
 429                 priv->bulk_in_buffer = kmalloc(priv->buffer_size, GFP_KERNEL);
 430                 if (!priv->bulk_in_buffer) {
 431                         dev_err(&priv->udev->dev, "out of memory\n");
 432                         goto error;
 433                 }
 434
 435                 priv->bulk_address = endpoint->bEndpointAddress;
 436
 437                 /* set up our bulk urb */
 438                 usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
 439                                   usb_rcvbulkpipe(priv->udev,
 440                                                   endpoint->bEndpointAddress),
 441                                   priv->bulk_in_buffer, priv->buffer_size,
 442                                   opticon_bulk_callback, priv);
 443
 444                 bulk_in_found = true;
 445                 break;
 446                 }
 447
 448         if (!bulk_in_found) {
 449                 dev_err(&priv->udev->dev,
 450                         "Error - the proper endpoints were not found!\n");
 451                 goto error;
 452         }
 453
 454         usb_set_serial_data(serial, priv);
 455         return 0;
 456
 457 error:
 458         usb_free_urb(priv->bulk_read_urb);
 459         kfree(priv->bulk_in_buffer);
 460         kfree(priv);
 461         return retval;
 462 }
 463
 464 static void opticon_disconnect(struct usb_serial *serial)
 465 {
 466         struct opticon_private *priv = usb_get_serial_data(serial);
 467
 468         dbg("%s", __func__);
 469
 470         usb_kill_urb(priv->bulk_read_urb);
 471         usb_free_urb(priv->bulk_read_urb);
 472 }
 473
 474 static void opticon_release(struct usb_serial *serial)
 475 {
 476         struct opticon_private *priv = usb_get_serial_data(serial);
 477
 478         dbg("%s", __func__);
 479
 480         kfree(priv->bulk_in_buffer);
 481         kfree(priv);
 482 }
 483
 484 static int opticon_suspend(struct usb_interface *intf, pm_message_t message)
 485 {
 486         struct usb_serial *serial = usb_get_intfdata(intf);
 487         struct opticon_private *priv = usb_get_serial_data(serial);
 488
 489         usb_kill_urb(priv->bulk_read_urb);
 490         return 0;
 491 }
 492
 493 static int opticon_resume(struct usb_interface *intf)
 494 {
 495         struct usb_serial *serial = usb_get_intfdata(intf);
 496         struct opticon_private *priv = usb_get_serial_data(serial);
 497         struct usb_serial_port *port = serial->port[0];
 498         int result;
 499
 500         mutex_lock(&port->port.mutex);
 501         /* This is protected by the port mutex against close/open */
 502         if (test_bit(ASYNCB_INITIALIZED, &port->port.flags))
 503                 result = usb_submit_urb(priv->bulk_read_urb, GFP_NOIO);
 504         else
 505                 result = 0;
 506         mutex_unlock(&port->port.mutex);
 507         return result;
 508 }
 509
 510 static struct usb_driver opticon_driver = {
 511         .name =         "opticon",
 512         .probe =        usb_serial_probe,
 513         .disconnect =   usb_serial_disconnect,
 514         .suspend =      opticon_suspend,
 515         .resume =       opticon_resume,
 516         .id_table =     id_table,
 517         .no_dynamic_id =        1,
 518 };
 519
 520 static struct usb_serial_driver opticon_device = {
 521         .driver = {
 522                 .owner =        THIS_MODULE,
 523                 .name =         "opticon",
 524         },
 525         .id_table =             id_table,
 526         .usb_driver =           &opticon_driver,
 527         .num_ports =            1,
 528         .attach =               opticon_startup,
 529         .open =                 opticon_open,
 530         .close =                opticon_close,
 531         .write =                opticon_write,
 532         .write_room =           opticon_write_room,
 533         .disconnect =           opticon_disconnect,
 534         .release =              opticon_release,
 535         .throttle =             opticon_throttle,
 536         .unthrottle =           opticon_unthrottle,
 537         .ioctl =                opticon_ioctl,
 538         .tiocmget =             opticon_tiocmget,
 539 };
 540
 541 static int __init opticon_init(void)
 542 {
 543         int retval;
 544
 545         retval = usb_serial_register(&opticon_device);
 546         if (retval)
 547                 return retval;
 548         retval = usb_register(&opticon_driver);
 549         if (retval)
 550                 usb_serial_deregister(&opticon_device);
 551         return retval;
 552 }
 553
 554 static void __exit opticon_exit(void)
 555 {
 556         usb_deregister(&opticon_driver);
 557         usb_serial_deregister(&opticon_device);
 558 }
 559
 560 module_init(opticon_init);
 561 module_exit(opticon_exit);
 562 MODULE_LICENSE("GPL");
 563
 564 module_param(debug, bool, S_IRUGO | S_IWUSR);
 565 MODULE_PARM_DESC(debug, "Debug enabled or not");