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;
 164
 165         buffer = kzalloc(1, GFP_KERNEL);
 166         if (!buffer)
 167                 return -ENOMEM;
 168
 169         buffer[0] = val;
 170         /* Send the message to the vendor control endpoint
 171          * of the connected device */
 172         retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
 173                                 requesttype,
 174                                 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
 175                                 0, 0, buffer, 1, 0);
 176         kfree(buffer);
 177
 178         return retval;
 179 }
 180
 181 static int opticon_open(struct tty_struct *tty, struct usb_serial_port *port)
 182 {
 183         struct opticon_private *priv = usb_get_serial_data(port->serial);
 184         unsigned long flags;
 185         int result = 0;
 186
 187         dbg("%s - port %d", __func__, port->number);
 188
 189         spin_lock_irqsave(&priv->lock, flags);
 190         priv->throttled = false;
 191         priv->actually_throttled = false;
 192         priv->port = port;
 193         priv->rts = false;
 194         spin_unlock_irqrestore(&priv->lock, flags);
 195
 196         /* Clear RTS line */
 197         send_control_msg(port, CONTROL_RTS, 0);
 198
 199         /* Setup the read URB and start reading from the device */
 200         usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
 201                           usb_rcvbulkpipe(priv->udev,
 202                                           priv->bulk_address),
 203                           priv->bulk_in_buffer, priv->buffer_size,
 204                           opticon_read_bulk_callback, priv);
 205
 206         /* clear the halt status of the enpoint */
 207         usb_clear_halt(priv->udev, priv->bulk_read_urb->pipe);
 208
 209         result = usb_submit_urb(priv->bulk_read_urb, GFP_KERNEL);
 210         if (result)
 211                 dev_err(&port->dev,
 212                         "%s - failed resubmitting read urb, error %d\n",
 213                         __func__, result);
 214         /* Request CTS line state, sometimes during opening the current
 215          * CTS state can be missed. */
 216         send_control_msg(port, RESEND_CTS_STATE, 1);
 217         return result;
 218 }
 219
 220 static void opticon_close(struct usb_serial_port *port)
 221 {
 222         struct opticon_private *priv = usb_get_serial_data(port->serial);
 223
 224         dbg("%s - port %d", __func__, port->number);
 225
 226         /* shutdown our urbs */
 227         usb_kill_urb(priv->bulk_read_urb);
 228 }
 229
 230 static void opticon_write_control_callback(struct urb *urb)
 231 {
 232         struct opticon_private *priv = urb->context;
 233         int status = urb->status;
 234         unsigned long flags;
 235
 236         /* free up the transfer buffer, as usb_free_urb() does not do this */
 237         kfree(urb->transfer_buffer);
 238
 239         /* setup packet may be set if we're using it for writing */
 240         kfree(urb->setup_packet);
 241
 242         if (status)
 243                 dbg("%s - nonzero write bulk status received: %d",
 244                     __func__, status);
 245
 246         spin_lock_irqsave(&priv->lock, flags);
 247         --priv->outstanding_urbs;
 248         spin_unlock_irqrestore(&priv->lock, flags);
 249
 250         usb_serial_port_softint(priv->port);
 251 }
 252
 253 static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
 254                          const unsigned char *buf, int count)
 255 {
 256         struct opticon_private *priv = usb_get_serial_data(port->serial);
 257         struct usb_serial *serial = port->serial;
 258         struct urb *urb;
 259         unsigned char *buffer;
 260         unsigned long flags;
 261         int status;
 262         struct usb_ctrlrequest *dr;
 263
 264         dbg("%s - port %d", __func__, port->number);
 265
 266         spin_lock_irqsave(&priv->lock, flags);
 267         if (priv->outstanding_urbs > URB_UPPER_LIMIT) {
 268                 spin_unlock_irqrestore(&priv->lock, flags);
 269                 dbg("%s - write limit hit", __func__);
 270                 return 0;
 271         }
 272         priv->outstanding_urbs++;
 273         spin_unlock_irqrestore(&priv->lock, flags);
 274
 275         buffer = kmalloc(count, GFP_ATOMIC);
 276         if (!buffer) {
 277                 dev_err(&port->dev, "out of memory\n");
 278                 count = -ENOMEM;
 279
 280                 goto error_no_buffer;
 281         }
 282
 283         urb = usb_alloc_urb(0, GFP_ATOMIC);
 284         if (!urb) {
 285                 dev_err(&port->dev, "no more free urbs\n");
 286                 count = -ENOMEM;
 287                 goto error_no_urb;
 288         }
 289
 290         memcpy(buffer, buf, count);
 291
 292         usb_serial_debug_data(debug, &port->dev, __func__, count, buffer);
 293
 294         /* The conncected devices do not have a bulk write endpoint,
 295          * to transmit data to de barcode device the control endpoint is used */
 296         dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO);
 297         if (!dr) {
 298                 dev_err(&port->dev, "out of memory\n");
 299                 count = -ENOMEM;
 300                 goto error_no_dr;
 301         }
 302
 303         dr->bRequestType = USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT;
 304         dr->bRequest = 0x01;
 305         dr->wValue = 0;
 306         dr->wIndex = 0;
 307         dr->wLength = cpu_to_le16(count);
 308
 309         usb_fill_control_urb(urb, serial->dev,
 310                 usb_sndctrlpipe(serial->dev, 0),
 311                 (unsigned char *)dr, buffer, count,
 312                 opticon_write_control_callback, priv);
 313
 314         /* send it down the pipe */
 315         status = usb_submit_urb(urb, GFP_ATOMIC);
 316         if (status) {
 317                 dev_err(&port->dev,
 318                 "%s - usb_submit_urb(write endpoint) failed status = %d\n",
 319                                                         __func__, status);
 320                 count = status;
 321                 goto error;
 322         }
 323
 324         /* we are done with this urb, so let the host driver
 325          * really free it when it is finished with it */
 326         usb_free_urb(urb);
 327
 328         return count;
 329 error:
 330         kfree(dr);
 331 error_no_dr:
 332         usb_free_urb(urb);
 333 error_no_urb:
 334         kfree(buffer);
 335 error_no_buffer:
 336         spin_lock_irqsave(&priv->lock, flags);
 337         --priv->outstanding_urbs;
 338         spin_unlock_irqrestore(&priv->lock, flags);
 339         return count;
 340 }
 341
 342 static int opticon_write_room(struct tty_struct *tty)
 343 {
 344         struct usb_serial_port *port = tty->driver_data;
 345         struct opticon_private *priv = usb_get_serial_data(port->serial);
 346         unsigned long flags;
 347
 348         dbg("%s - port %d", __func__, port->number);
 349
 350         /*
 351          * We really can take almost anything the user throws at us
 352          * but let's pick a nice big number to tell the tty
 353          * layer that we have lots of free space, unless we don't.
 354          */
 355         spin_lock_irqsave(&priv->lock, flags);
 356         if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) {
 357                 spin_unlock_irqrestore(&priv->lock, flags);
 358                 dbg("%s - write limit hit", __func__);
 359                 return 0;
 360         }
 361         spin_unlock_irqrestore(&priv->lock, flags);
 362
 363         return 2048;
 364 }
 365
 366 static void opticon_throttle(struct tty_struct *tty)
 367 {
 368         struct usb_serial_port *port = tty->driver_data;
 369         struct opticon_private *priv = usb_get_serial_data(port->serial);
 370         unsigned long flags;
 371
 372         dbg("%s - port %d", __func__, port->number);
 373         spin_lock_irqsave(&priv->lock, flags);
 374         priv->throttled = true;
 375         spin_unlock_irqrestore(&priv->lock, flags);
 376 }
 377
 378
 379 static void opticon_unthrottle(struct tty_struct *tty)
 380 {
 381         struct usb_serial_port *port = tty->driver_data;
 382         struct opticon_private *priv = usb_get_serial_data(port->serial);
 383         unsigned long flags;
 384         int result, was_throttled;
 385
 386         dbg("%s - port %d", __func__, port->number);
 387
 388         spin_lock_irqsave(&priv->lock, flags);
 389         priv->throttled = false;
 390         was_throttled = priv->actually_throttled;
 391         priv->actually_throttled = false;
 392         spin_unlock_irqrestore(&priv->lock, flags);
 393
 394         priv->bulk_read_urb->dev = port->serial->dev;
 395         if (was_throttled) {
 396                 result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC);
 397                 if (result)
 398                         dev_err(&port->dev,
 399                                 "%s - failed submitting read urb, error %d\n",
 400                                                         __func__, result);
 401         }
 402 }
 403
 404 static int opticon_tiocmget(struct tty_struct *tty)
 405 {
 406         struct usb_serial_port *port = tty->driver_data;
 407         struct opticon_private *priv = usb_get_serial_data(port->serial);
 408         unsigned long flags;
 409         int result = 0;
 410
 411         dbg("%s - port %d", __func__, port->number);
 412         if (!usb_get_intfdata(port->serial->interface))
 413                 return -ENODEV;
 414
 415         spin_lock_irqsave(&priv->lock, flags);
 416         if (priv->rts)
 417                 result |= TIOCM_RTS;
 418         if (priv->cts)
 419                 result |= TIOCM_CTS;
 420         spin_unlock_irqrestore(&priv->lock, flags);
 421
 422         dbg("%s - %x", __func__, result);
 423         return result;
 424 }
 425
 426 static int opticon_tiocmset(struct tty_struct *tty,
 427                            unsigned int set, unsigned int clear)
 428 {
 429         struct usb_serial_port *port = tty->driver_data;
 430         struct opticon_private *priv = usb_get_serial_data(port->serial);
 431         unsigned long flags;
 432         bool rts;
 433         bool changed = false;
 434
 435         if (!usb_get_intfdata(port->serial->interface))
 436                 return -ENODEV;
 437         /* We only support RTS so we only handle that */
 438         spin_lock_irqsave(&priv->lock, flags);
 439
 440         rts = priv->rts;
 441         if (set & TIOCM_RTS)
 442                 priv->rts = true;
 443         if (clear & TIOCM_RTS)
 444                 priv->rts = false;
 445         changed = rts ^ priv->rts;
 446         spin_unlock_irqrestore(&priv->lock, flags);
 447
 448         if (!changed)
 449                 return 0;
 450
 451         /* Send the new RTS state to the connected device */
 452         return send_control_msg(port, CONTROL_RTS, !rts);
 453 }
 454
 455 static int get_serial_info(struct opticon_private *priv,
 456                            struct serial_struct __user *serial)
 457 {
 458         struct serial_struct tmp;
 459
 460         if (!serial)
 461                 return -EFAULT;
 462
 463         memset(&tmp, 0x00, sizeof(tmp));
 464
 465         /* fake emulate a 16550 uart to make userspace code happy */
 466         tmp.type                = PORT_16550A;
 467         tmp.line                = priv->serial->minor;
 468         tmp.port                = 0;
 469         tmp.irq                 = 0;
 470         tmp.flags               = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
 471         tmp.xmit_fifo_size      = 1024;
 472         tmp.baud_base           = 9600;
 473         tmp.close_delay         = 5*HZ;
 474         tmp.closing_wait        = 30*HZ;
 475
 476         if (copy_to_user(serial, &tmp, sizeof(*serial)))
 477                 return -EFAULT;
 478         return 0;
 479 }
 480
 481 static int opticon_ioctl(struct tty_struct *tty,
 482                          unsigned int cmd, unsigned long arg)
 483 {
 484         struct usb_serial_port *port = tty->driver_data;
 485         struct opticon_private *priv = usb_get_serial_data(port->serial);
 486
 487         dbg("%s - port %d, cmd = 0x%x", __func__, port->number, cmd);
 488
 489         switch (cmd) {
 490         case TIOCGSERIAL:
 491                 return get_serial_info(priv,
 492                                        (struct serial_struct __user *)arg);
 493         }
 494
 495         return -ENOIOCTLCMD;
 496 }
 497
 498 static int opticon_startup(struct usb_serial *serial)
 499 {
 500         struct opticon_private *priv;
 501         struct usb_host_interface *intf;
 502         int i;
 503         int retval = -ENOMEM;
 504         bool bulk_in_found = false;
 505
 506         /* create our private serial structure */
 507         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 508         if (priv == NULL) {
 509                 dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__);
 510                 return -ENOMEM;
 511         }
 512         spin_lock_init(&priv->lock);
 513         priv->serial = serial;
 514         priv->port = serial->port[0];
 515         priv->udev = serial->dev;
 516         priv->outstanding_urbs = 0;     /* Init the outstanding urbs */
 517
 518         /* find our bulk endpoint */
 519         intf = serial->interface->altsetting;
 520         for (i = 0; i < intf->desc.bNumEndpoints; ++i) {
 521                 struct usb_endpoint_descriptor *endpoint;
 522
 523                 endpoint = &intf->endpoint[i].desc;
 524                 if (!usb_endpoint_is_bulk_in(endpoint))
 525                         continue;
 526
 527                 priv->bulk_read_urb = usb_alloc_urb(0, GFP_KERNEL);
 528                 if (!priv->bulk_read_urb) {
 529                         dev_err(&priv->udev->dev, "out of memory\n");
 530                         goto error;
 531                 }
 532
 533                 priv->buffer_size = usb_endpoint_maxp(endpoint) * 2;
 534                 priv->bulk_in_buffer = kmalloc(priv->buffer_size, GFP_KERNEL);
 535                 if (!priv->bulk_in_buffer) {
 536                         dev_err(&priv->udev->dev, "out of memory\n");
 537                         goto error;
 538                 }
 539
 540                 priv->bulk_address = endpoint->bEndpointAddress;
 541
 542                 bulk_in_found = true;
 543                 break;
 544                 }
 545
 546         if (!bulk_in_found) {
 547                 dev_err(&priv->udev->dev,
 548                         "Error - the proper endpoints were not found!\n");
 549                 goto error;
 550         }
 551
 552         usb_set_serial_data(serial, priv);
 553         return 0;
 554
 555 error:
 556         usb_free_urb(priv->bulk_read_urb);
 557         kfree(priv->bulk_in_buffer);
 558         kfree(priv);
 559         return retval;
 560 }
 561
 562 static void opticon_disconnect(struct usb_serial *serial)
 563 {
 564         struct opticon_private *priv = usb_get_serial_data(serial);
 565
 566         dbg("%s", __func__);
 567
 568         usb_kill_urb(priv->bulk_read_urb);
 569         usb_free_urb(priv->bulk_read_urb);
 570 }
 571
 572 static void opticon_release(struct usb_serial *serial)
 573 {
 574         struct opticon_private *priv = usb_get_serial_data(serial);
 575
 576         dbg("%s", __func__);
 577
 578         kfree(priv->bulk_in_buffer);
 579         kfree(priv);
 580 }
 581
 582 static int opticon_suspend(struct usb_interface *intf, pm_message_t message)
 583 {
 584         struct usb_serial *serial = usb_get_intfdata(intf);
 585         struct opticon_private *priv = usb_get_serial_data(serial);
 586
 587         usb_kill_urb(priv->bulk_read_urb);
 588         return 0;
 589 }
 590
 591 static int opticon_resume(struct usb_interface *intf)
 592 {
 593         struct usb_serial *serial = usb_get_intfdata(intf);
 594         struct opticon_private *priv = usb_get_serial_data(serial);
 595         struct usb_serial_port *port = serial->port[0];
 596         int result;
 597
 598         mutex_lock(&port->port.mutex);
 599         /* This is protected by the port mutex against close/open */
 600         if (test_bit(ASYNCB_INITIALIZED, &port->port.flags))
 601                 result = usb_submit_urb(priv->bulk_read_urb, GFP_NOIO);
 602         else
 603                 result = 0;
 604         mutex_unlock(&port->port.mutex);
 605         return result;
 606 }
 607
 608 static struct usb_driver opticon_driver = {
 609         .name =         "opticon",
 610         .probe =        usb_serial_probe,
 611         .disconnect =   usb_serial_disconnect,
 612         .suspend =      opticon_suspend,
 613         .resume =       opticon_resume,
 614         .id_table =     id_table,
 615         .no_dynamic_id =        1,
 616 };
 617
 618 static struct usb_serial_driver opticon_device = {
 619         .driver = {
 620                 .owner =        THIS_MODULE,
 621                 .name =         "opticon",
 622         },
 623         .id_table =             id_table,
 624         .usb_driver =           &opticon_driver,
 625         .num_ports =            1,
 626         .attach =               opticon_startup,
 627         .open =                 opticon_open,
 628         .close =                opticon_close,
 629         .write =                opticon_write,
 630         .write_room =           opticon_write_room,
 631         .disconnect =           opticon_disconnect,
 632         .release =              opticon_release,
 633         .throttle =             opticon_throttle,
 634         .unthrottle =           opticon_unthrottle,
 635         .ioctl =                opticon_ioctl,
 636         .tiocmget =             opticon_tiocmget,
 637         .tiocmset =             opticon_tiocmset,
 638 };
 639
 640 static int __init opticon_init(void)
 641 {
 642         int retval;
 643
 644         retval = usb_serial_register(&opticon_device);
 645         if (retval)
 646                 return retval;
 647         retval = usb_register(&opticon_driver);
 648         if (retval)
 649                 usb_serial_deregister(&opticon_device);
 650         return retval;
 651 }
 652
 653 static void __exit opticon_exit(void)
 654 {
 655         usb_deregister(&opticon_driver);
 656         usb_serial_deregister(&opticon_device);
 657 }
 658
 659 module_init(opticon_init);
 660 module_exit(opticon_exit);
 661 MODULE_DESCRIPTION(DRIVER_DESC);
 662 MODULE_LICENSE("GPL");
 663
 664 module_param(debug, bool, S_IRUGO | S_IWUSR);
 665 MODULE_PARM_DESC(debug, "Debug enabled or not");