drivers/usb/serial/opticon.c

   1 /*
   2  * Opticon USB barcode to serial driver
   3  *
   4  * Copyright (C) 2011 Martin Jansen <martin.jansen@opticon.com>
   5  * Copyright (C) 2008 - 2009 Greg Kroah-Hartman <gregkh@suse.de>
   6  * Copyright (C) 2008 - 2009 Novell Inc.
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License version
  10  *      2 as published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/init.h>
  15 #include <linux/tty.h>
  16 #include <linux/tty_driver.h>
  17 #include <linux/slab.h>
  18 #include <linux/tty_flip.h>
  19 #include <linux/serial.h>
  20 #include <linux/module.h>
  21 #include <linux/usb.h>
  22 #include <linux/usb/serial.h>
  23 #include <linux/uaccess.h>
  24
  25 #define CONTROL_RTS                     0x02
  26 #define RESEND_CTS_STATE        0x03
  27
  28 /* max number of write urbs in flight */
  29 #define URB_UPPER_LIMIT 8
  30
  31 /* This driver works for the Opticon 1D barcode reader
  32  * an examples of 1D barcode types are EAN, UPC, Code39, IATA etc.. */
  33 #define DRIVER_DESC     "Opticon USB barcode to serial driver (1D)"
  34
  35 static int debug;
  36
  37 static const struct usb_device_id id_table[] = {
  38         { USB_DEVICE(0x065a, 0x0009) },
  39         { },
  40 };
  41 MODULE_DEVICE_TABLE(usb, id_table);
  42
  43 /* This structure holds all of the individual device information */
  44 struct opticon_private {
  45         struct usb_device *udev;
  46         struct usb_serial *serial;
  47         struct usb_serial_port *port;
  48         unsigned char *bulk_in_buffer;
  49         struct urb *bulk_read_urb;
  50         int buffer_size;
  51         u8 bulk_address;
  52         spinlock_t lock;        /* protects the following flags */
  53         bool throttled;
  54         bool actually_throttled;
  55         bool rts;
  56         bool cts;
  57         int outstanding_urbs;
  58 };
  59
  60
  61
  62 static void opticon_read_bulk_callback(struct urb *urb)
  63 {
  64         struct opticon_private *priv = urb->context;
  65         unsigned char *data = urb->transfer_buffer;
  66         struct usb_serial_port *port = priv->port;
  67         int status = urb->status;
  68         struct tty_struct *tty;
  69         int result;
  70         int data_length;
  71         unsigned long flags;
  72
  73         dbg("%s - port %d", __func__, port->number);
  74
  75         switch (status) {
  76         case 0:
  77                 /* success */
  78                 break;
  79         case -ECONNRESET:
  80         case -ENOENT:
  81         case -ESHUTDOWN:
  82                 /* this urb is terminated, clean up */
  83                 dbg("%s - urb shutting down with status: %d",
  84                     __func__, status);
  85                 return;
  86         default:
  87                 dbg("%s - nonzero urb status received: %d",
  88                     __func__, status);
  89                 goto exit;
  90         }
  91
  92         usb_serial_debug_data(debug, &port->dev, __func__, urb->actual_length,
  93                               data);
  94
  95         if (urb->actual_length > 2) {
  96                 data_length = urb->actual_length - 2;
  97
  98                 /*
  99                  * Data from the device comes with a 2 byte header:
 100                  *
 101                  * <0x00><0x00>data...
 102                  *      This is real data to be sent to the tty layer
 103                  * <0x00><0x01)level
 104                  *      This is a CTS level change, the third byte is the CTS
 105                  *      value (0 for low, 1 for high).
 106                  */
 107                 if ((data[0] == 0x00) && (data[1] == 0x00)) {
 108                         /* real data, send it to the tty layer */
 109                         tty = tty_port_tty_get(&port->port);
 110                         if (tty) {
 111                                 tty_insert_flip_string(tty, data + 2,
 112                                                        data_length);
 113                                 tty_flip_buffer_push(tty);
 114                                 tty_kref_put(tty);
 115                         }
 116                 } else {
 117                         if ((data[0] == 0x00) && (data[1] == 0x01)) {
 118                                 spin_lock_irqsave(&priv->lock, flags);
 119                                 /* CTS status information package */
 120                                 if (data[2] == 0x00)
 121                                         priv->cts = false;
 122                                 else
 123                                         priv->cts = true;
 124                                 spin_unlock_irqrestore(&priv->lock, flags);
 125                         } else {
 126                                 dev_dbg(&priv->udev->dev,
 127                                         "Unknown data packet received from the device:"
 128                                         " %2x %2x\n",
 129                                         data[0], data[1]);
 130                         }
 131                 }
 132         } else {
 133                 dev_dbg(&priv->udev->dev,
 134                         "Improper amount of data received from the device, "
 135                         "%d bytes", urb->actual_length);
 136         }
 137
 138 exit:
 139         spin_lock(&priv->lock);
 140
 141         /* Continue trying to always read if we should */
 142         if (!priv->throttled) {
 143                 usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
 144                                   usb_rcvbulkpipe(priv->udev,
 145                                                   priv->bulk_address),
 146                                   priv->bulk_in_buffer, priv->buffer_size,
 147                                   opticon_read_bulk_callback, priv);
 148                 result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC);
 149                 if (result)
 150                         dev_err(&port->dev,
 151                             "%s - failed resubmitting read urb, error %d\n",
 152                                                         __func__, result);
 153         } else
 154                 priv->actually_throttled = true;
 155         spin_unlock(&priv->lock);
 156 }
 157
 158 static int send_control_msg(struct usb_serial_port *port, u8 requesttype,
 159                                 u8 val)
 160 {
 161         struct usb_serial *serial = port->serial;
 162         int retval;
 163         u8 buffer[2];
 164
 165         buffer[0] = val;
 166         /* Send the message to the vendor control endpoint
 167          * of the connected device */
 168         retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
 169                                 requesttype,
 170                                 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
 171                                 0, 0, buffer, 1, 0);
 172
 173         return retval;
 174 }
 175
 176 static int opticon_open(struct tty_struct *tty, struct usb_serial_port *port)
 177 {
 178         struct opticon_private *priv = usb_get_serial_data(port->serial);
 179         unsigned long flags;
 180         int result = 0;
 181
 182         dbg("%s - port %d", __func__, port->number);
 183
 184         spin_lock_irqsave(&priv->lock, flags);
 185         priv->throttled = false;
 186         priv->actually_throttled = false;
 187         priv->port = port;
 188         priv->rts = false;
 189         spin_unlock_irqrestore(&priv->lock, flags);
 190
 191         /* Clear RTS line */
 192         send_control_msg(port, CONTROL_RTS, 0);
 193
 194         /* Setup the read URB and start reading from the device */
 195         usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
 196                           usb_rcvbulkpipe(priv->udev,
 197                                           priv->bulk_address),
 198                           priv->bulk_in_buffer, priv->buffer_size,
 199                           opticon_read_bulk_callback, priv);
 200
 201         /* clear the halt status of the enpoint */
 202         usb_clear_halt(priv->udev, priv->bulk_read_urb->pipe);
 203
 204         result = usb_submit_urb(priv->bulk_read_urb, GFP_KERNEL);
 205         if (result)
 206                 dev_err(&port->dev,
 207                         "%s - failed resubmitting read urb, error %d\n",
 208                         __func__, result);
 209         /* Request CTS line state, sometimes during opening the current
 210          * CTS state can be missed. */
 211         send_control_msg(port, RESEND_CTS_STATE, 1);
 212         return result;
 213 }
 214
 215 static void opticon_close(struct usb_serial_port *port)
 216 {
 217         struct opticon_private *priv = usb_get_serial_data(port->serial);
 218
 219         dbg("%s - port %d", __func__, port->number);
 220
 221         /* shutdown our urbs */
 222         usb_kill_urb(priv->bulk_read_urb);
 223 }
 224
 225 static void opticon_write_control_callback(struct urb *urb)
 226 {
 227         struct opticon_private *priv = urb->context;
 228         int status = urb->status;
 229         unsigned long flags;
 230
 231         /* free up the transfer buffer, as usb_free_urb() does not do this */
 232         kfree(urb->transfer_buffer);
 233
 234         /* setup packet may be set if we're using it for writing */
 235         kfree(urb->setup_packet);
 236
 237         if (status)
 238                 dbg("%s - nonzero write bulk status received: %d",
 239                     __func__, status);
 240
 241         spin_lock_irqsave(&priv->lock, flags);
 242         --priv->outstanding_urbs;
 243         spin_unlock_irqrestore(&priv->lock, flags);
 244
 245         usb_serial_port_softint(priv->port);
 246 }
 247
 248 static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
 249                          const unsigned char *buf, int count)
 250 {
 251         struct opticon_private *priv = usb_get_serial_data(port->serial);
 252         struct usb_serial *serial = port->serial;
 253         struct urb *urb;
 254         unsigned char *buffer;
 255         unsigned long flags;
 256         int status;
 257         struct usb_ctrlrequest *dr;
 258
 259         dbg("%s - port %d", __func__, port->number);
 260
 261         spin_lock_irqsave(&priv->lock, flags);
 262         if (priv->outstanding_urbs > URB_UPPER_LIMIT) {
 263                 spin_unlock_irqrestore(&priv->lock, flags);
 264                 dbg("%s - write limit hit", __func__);
 265                 return 0;
 266         }
 267         priv->outstanding_urbs++;
 268         spin_unlock_irqrestore(&priv->lock, flags);
 269
 270         buffer = kmalloc(count, GFP_ATOMIC);
 271         if (!buffer) {
 272                 dev_err(&port->dev, "out of memory\n");
 273                 count = -ENOMEM;
 274
 275                 goto error_no_buffer;
 276         }
 277
 278         urb = usb_alloc_urb(0, GFP_ATOMIC);
 279         if (!urb) {
 280                 dev_err(&port->dev, "no more free urbs\n");
 281                 count = -ENOMEM;
 282                 goto error_no_urb;
 283         }
 284
 285         memcpy(buffer, buf, count);
 286
 287         usb_serial_debug_data(debug, &port->dev, __func__, count, buffer);
 288
 289         /* The conncected devices do not have a bulk write endpoint,
 290          * to transmit data to de barcode device the control endpoint is used */
 291         dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO);
 292         if (!dr) {
 293                 dev_err(&port->dev, "out of memory\n");
 294                 count = -ENOMEM;
 295                 goto error;
 296         }
 297
 298         dr->bRequestType = USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT;
 299         dr->bRequest = 0x01;
 300         dr->wValue = 0;
 301         dr->wIndex = 0;
 302         dr->wLength = cpu_to_le16(count);
 303
 304         usb_fill_control_urb(urb, serial->dev,
 305                 usb_sndctrlpipe(serial->dev, 0),
 306                 (unsigned char *)dr, buffer, count,
 307                 opticon_write_control_callback, priv);
 308
 309         /* send it down the pipe */
 310         status = usb_submit_urb(urb, GFP_ATOMIC);
 311         if (status) {
 312                 dev_err(&port->dev,
 313                 "%s - usb_submit_urb(write endpoint) failed status = %d\n",
 314                                                         __func__, status);
 315                 count = status;
 316                 goto error;
 317         }
 318
 319         /* we are done with this urb, so let the host driver
 320          * really free it when it is finished with it */
 321         usb_free_urb(urb);
 322
 323         return count;
 324 error:
 325         usb_free_urb(urb);
 326 error_no_urb:
 327         kfree(buffer);
 328 error_no_buffer:
 329         spin_lock_irqsave(&priv->lock, flags);
 330         --priv->outstanding_urbs;
 331         spin_unlock_irqrestore(&priv->lock, flags);
 332         return count;
 333 }
 334
 335 static int opticon_write_room(struct tty_struct *tty)
 336 {
 337         struct usb_serial_port *port = tty->driver_data;
 338         struct opticon_private *priv = usb_get_serial_data(port->serial);
 339         unsigned long flags;
 340
 341         dbg("%s - port %d", __func__, port->number);
 342
 343         /*
 344          * We really can take almost anything the user throws at us
 345          * but let's pick a nice big number to tell the tty
 346          * layer that we have lots of free space, unless we don't.
 347          */
 348         spin_lock_irqsave(&priv->lock, flags);
 349         if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) {
 350                 spin_unlock_irqrestore(&priv->lock, flags);
 351                 dbg("%s - write limit hit", __func__);
 352                 return 0;
 353         }
 354         spin_unlock_irqrestore(&priv->lock, flags);
 355
 356         return 2048;
 357 }
 358
 359 static void opticon_throttle(struct tty_struct *tty)
 360 {
 361         struct usb_serial_port *port = tty->driver_data;
 362         struct opticon_private *priv = usb_get_serial_data(port->serial);
 363         unsigned long flags;
 364
 365         dbg("%s - port %d", __func__, port->number);
 366         spin_lock_irqsave(&priv->lock, flags);
 367         priv->throttled = true;
 368         spin_unlock_irqrestore(&priv->lock, flags);
 369 }
 370
 371
 372 static void opticon_unthrottle(struct tty_struct *tty)
 373 {
 374         struct usb_serial_port *port = tty->driver_data;
 375         struct opticon_private *priv = usb_get_serial_data(port->serial);
 376         unsigned long flags;
 377         int result, was_throttled;
 378
 379         dbg("%s - port %d", __func__, port->number);
 380
 381         spin_lock_irqsave(&priv->lock, flags);
 382         priv->throttled = false;
 383         was_throttled = priv->actually_throttled;
 384         priv->actually_throttled = false;
 385         spin_unlock_irqrestore(&priv->lock, flags);
 386
 387         priv->bulk_read_urb->dev = port->serial->dev;
 388         if (was_throttled) {
 389                 result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC);
 390                 if (result)
 391                         dev_err(&port->dev,
 392                                 "%s - failed submitting read urb, error %d\n",
 393                                                         __func__, result);
 394         }
 395 }
 396
 397 static int opticon_tiocmget(struct tty_struct *tty)
 398 {
 399         struct usb_serial_port *port = tty->driver_data;
 400         struct opticon_private *priv = usb_get_serial_data(port->serial);
 401         unsigned long flags;
 402         int result = 0;
 403
 404         dbg("%s - port %d", __func__, port->number);
 405         if (!usb_get_intfdata(port->serial->interface))
 406                 return -ENODEV;
 407
 408         spin_lock_irqsave(&priv->lock, flags);
 409         if (priv->rts)
 410                 result |= TIOCM_RTS;
 411         if (priv->cts)
 412                 result |= TIOCM_CTS;
 413         spin_unlock_irqrestore(&priv->lock, flags);
 414
 415         dbg("%s - %x", __func__, result);
 416         return result;
 417 }
 418
 419 static int opticon_tiocmset(struct tty_struct *tty,
 420                            unsigned int set, unsigned int clear)
 421 {
 422         struct usb_serial_port *port = tty->driver_data;
 423         struct opticon_private *priv = usb_get_serial_data(port->serial);
 424         unsigned long flags;
 425         bool rts;
 426         bool changed = false;
 427
 428         if (!usb_get_intfdata(port->serial->interface))
 429                 return -ENODEV;
 430         /* We only support RTS so we only handle that */
 431         spin_lock_irqsave(&priv->lock, flags);
 432
 433         rts = priv->rts;
 434         if (set & TIOCM_RTS)
 435                 priv->rts = true;
 436         if (clear & TIOCM_RTS)
 437                 priv->rts = false;
 438         changed = rts ^ priv->rts;
 439         spin_unlock_irqrestore(&priv->lock, flags);
 440
 441         if (!changed)
 442                 return 0;
 443
 444         /* Send the new RTS state to the connected device */
 445         return send_control_msg(port, CONTROL_RTS, !rts);
 446 }
 447
 448 static int get_serial_info(struct opticon_private *priv,
 449                            struct serial_struct __user *serial)
 450 {
 451         struct serial_struct tmp;
 452
 453         if (!serial)
 454                 return -EFAULT;
 455
 456         memset(&tmp, 0x00, sizeof(tmp));
 457
 458         /* fake emulate a 16550 uart to make userspace code happy */
 459         tmp.type                = PORT_16550A;
 460         tmp.line                = priv->serial->minor;
 461         tmp.port                = 0;
 462         tmp.irq                 = 0;
 463         tmp.flags               = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
 464         tmp.xmit_fifo_size      = 1024;
 465         tmp.baud_base           = 9600;
 466         tmp.close_delay         = 5*HZ;
 467         tmp.closing_wait        = 30*HZ;
 468
 469         if (copy_to_user(serial, &tmp, sizeof(*serial)))
 470                 return -EFAULT;
 471         return 0;
 472 }
 473
 474 static int opticon_ioctl(struct tty_struct *tty,
 475                          unsigned int cmd, unsigned long arg)
 476 {
 477         struct usb_serial_port *port = tty->driver_data;
 478         struct opticon_private *priv = usb_get_serial_data(port->serial);
 479
 480         dbg("%s - port %d, cmd = 0x%x", __func__, port->number, cmd);
 481
 482         switch (cmd) {
 483         case TIOCGSERIAL:
 484                 return get_serial_info(priv,
 485                                        (struct serial_struct __user *)arg);
 486         }
 487
 488         return -ENOIOCTLCMD;
 489 }
 490
 491 static int opticon_startup(struct usb_serial *serial)
 492 {
 493         struct opticon_private *priv;
 494         struct usb_host_interface *intf;
 495         int i;
 496         int retval = -ENOMEM;
 497         bool bulk_in_found = false;
 498
 499         /* create our private serial structure */
 500         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 501         if (priv == NULL) {
 502                 dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__);
 503                 return -ENOMEM;
 504         }
 505         spin_lock_init(&priv->lock);
 506         priv->serial = serial;
 507         priv->port = serial->port[0];
 508         priv->udev = serial->dev;
 509         priv->outstanding_urbs = 0;     /* Init the outstanding urbs */
 510
 511         /* find our bulk endpoint */
 512         intf = serial->interface->altsetting;
 513         for (i = 0; i < intf->desc.bNumEndpoints; ++i) {
 514                 struct usb_endpoint_descriptor *endpoint;
 515
 516                 endpoint = &intf->endpoint[i].desc;
 517                 if (!usb_endpoint_is_bulk_in(endpoint))
 518                         continue;
 519
 520                 priv->bulk_read_urb = usb_alloc_urb(0, GFP_KERNEL);
 521                 if (!priv->bulk_read_urb) {
 522                         dev_err(&priv->udev->dev, "out of memory\n");
 523                         goto error;
 524                 }
 525
 526                 priv->buffer_size = usb_endpoint_maxp(endpoint) * 2;
 527                 priv->bulk_in_buffer = kmalloc(priv->buffer_size, GFP_KERNEL);
 528                 if (!priv->bulk_in_buffer) {
 529                         dev_err(&priv->udev->dev, "out of memory\n");
 530                         goto error;
 531                 }
 532
 533                 priv->bulk_address = endpoint->bEndpointAddress;
 534
 535                 bulk_in_found = true;
 536                 break;
 537                 }
 538
 539         if (!bulk_in_found) {
 540                 dev_err(&priv->udev->dev,
 541                         "Error - the proper endpoints were not found!\n");
 542                 goto error;
 543         }
 544
 545         usb_set_serial_data(serial, priv);
 546         return 0;
 547
 548 error:
 549         usb_free_urb(priv->bulk_read_urb);
 550         kfree(priv->bulk_in_buffer);
 551         kfree(priv);
 552         return retval;
 553 }
 554
 555 static void opticon_disconnect(struct usb_serial *serial)
 556 {
 557         struct opticon_private *priv = usb_get_serial_data(serial);
 558
 559         dbg("%s", __func__);
 560
 561         usb_kill_urb(priv->bulk_read_urb);
 562         usb_free_urb(priv->bulk_read_urb);
 563 }
 564
 565 static void opticon_release(struct usb_serial *serial)
 566 {
 567         struct opticon_private *priv = usb_get_serial_data(serial);
 568
 569         dbg("%s", __func__);
 570
 571         kfree(priv->bulk_in_buffer);
 572         kfree(priv);
 573 }
 574
 575 static int opticon_suspend(struct usb_interface *intf, pm_message_t message)
 576 {
 577         struct usb_serial *serial = usb_get_intfdata(intf);
 578         struct opticon_private *priv = usb_get_serial_data(serial);
 579
 580         usb_kill_urb(priv->bulk_read_urb);
 581         return 0;
 582 }
 583
 584 static int opticon_resume(struct usb_interface *intf)
 585 {
 586         struct usb_serial *serial = usb_get_intfdata(intf);
 587         struct opticon_private *priv = usb_get_serial_data(serial);
 588         struct usb_serial_port *port = serial->port[0];
 589         int result;
 590
 591         mutex_lock(&port->port.mutex);
 592         /* This is protected by the port mutex against close/open */
 593         if (test_bit(ASYNCB_INITIALIZED, &port->port.flags))
 594                 result = usb_submit_urb(priv->bulk_read_urb, GFP_NOIO);
 595         else
 596                 result = 0;
 597         mutex_unlock(&port->port.mutex);
 598         return result;
 599 }
 600
 601 static struct usb_driver opticon_driver = {
 602         .name =         "opticon",
 603         .probe =        usb_serial_probe,
 604         .disconnect =   usb_serial_disconnect,
 605         .suspend =      opticon_suspend,
 606         .resume =       opticon_resume,
 607         .id_table =     id_table,
 608         .no_dynamic_id =        1,
 609 };
 610
 611 static struct usb_serial_driver opticon_device = {
 612         .driver = {
 613                 .owner =        THIS_MODULE,
 614                 .name =         "opticon",
 615         },
 616         .id_table =             id_table,
 617         .usb_driver =           &opticon_driver,
 618         .num_ports =            1,
 619         .attach =               opticon_startup,
 620         .open =                 opticon_open,
 621         .close =                opticon_close,
 622         .write =                opticon_write,
 623         .write_room =           opticon_write_room,
 624         .disconnect =           opticon_disconnect,
 625         .release =              opticon_release,
 626         .throttle =             opticon_throttle,
 627         .unthrottle =           opticon_unthrottle,
 628         .ioctl =                opticon_ioctl,
 629         .tiocmget =             opticon_tiocmget,
 630         .tiocmset =             opticon_tiocmset,
 631 };
 632
 633 static int __init opticon_init(void)
 634 {
 635         int retval;
 636
 637         retval = usb_serial_register(&opticon_device);
 638         if (retval)
 639                 return retval;
 640         retval = usb_register(&opticon_driver);
 641         if (retval)
 642                 usb_serial_deregister(&opticon_device);
 643         return retval;
 644 }
 645
 646 static void __exit opticon_exit(void)
 647 {
 648         usb_deregister(&opticon_driver);
 649         usb_serial_deregister(&opticon_device);
 650 }
 651
 652 module_init(opticon_init);
 653 module_exit(opticon_exit);
 654 MODULE_DESCRIPTION(DRIVER_DESC);
 655 MODULE_LICENSE("GPL");
 656
 657 module_param(debug, bool, S_IRUGO | S_IWUSR);
 658 MODULE_PARM_DESC(debug, "Debug enabled or not");