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;
 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         usb_free_urb(urb);
 331 error_no_urb:
 332         kfree(buffer);
 333 error_no_buffer:
 334         spin_lock_irqsave(&priv->lock, flags);
 335         --priv->outstanding_urbs;
 336         spin_unlock_irqrestore(&priv->lock, flags);
 337         return count;
 338 }
 339
 340 static int opticon_write_room(struct tty_struct *tty)
 341 {
 342         struct usb_serial_port *port = tty->driver_data;
 343         struct opticon_private *priv = usb_get_serial_data(port->serial);
 344         unsigned long flags;
 345
 346         dbg("%s - port %d", __func__, port->number);
 347
 348         /*
 349          * We really can take almost anything the user throws at us
 350          * but let's pick a nice big number to tell the tty
 351          * layer that we have lots of free space, unless we don't.
 352          */
 353         spin_lock_irqsave(&priv->lock, flags);
 354         if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) {
 355                 spin_unlock_irqrestore(&priv->lock, flags);
 356                 dbg("%s - write limit hit", __func__);
 357                 return 0;
 358         }
 359         spin_unlock_irqrestore(&priv->lock, flags);
 360
 361         return 2048;
 362 }
 363
 364 static void opticon_throttle(struct tty_struct *tty)
 365 {
 366         struct usb_serial_port *port = tty->driver_data;
 367         struct opticon_private *priv = usb_get_serial_data(port->serial);
 368         unsigned long flags;
 369
 370         dbg("%s - port %d", __func__, port->number);
 371         spin_lock_irqsave(&priv->lock, flags);
 372         priv->throttled = true;
 373         spin_unlock_irqrestore(&priv->lock, flags);
 374 }
 375
 376
 377 static void opticon_unthrottle(struct tty_struct *tty)
 378 {
 379         struct usb_serial_port *port = tty->driver_data;
 380         struct opticon_private *priv = usb_get_serial_data(port->serial);
 381         unsigned long flags;
 382         int result, was_throttled;
 383
 384         dbg("%s - port %d", __func__, port->number);
 385
 386         spin_lock_irqsave(&priv->lock, flags);
 387         priv->throttled = false;
 388         was_throttled = priv->actually_throttled;
 389         priv->actually_throttled = false;
 390         spin_unlock_irqrestore(&priv->lock, flags);
 391
 392         priv->bulk_read_urb->dev = port->serial->dev;
 393         if (was_throttled) {
 394                 result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC);
 395                 if (result)
 396                         dev_err(&port->dev,
 397                                 "%s - failed submitting read urb, error %d\n",
 398                                                         __func__, result);
 399         }
 400 }
 401
 402 static int opticon_tiocmget(struct tty_struct *tty)
 403 {
 404         struct usb_serial_port *port = tty->driver_data;
 405         struct opticon_private *priv = usb_get_serial_data(port->serial);
 406         unsigned long flags;
 407         int result = 0;
 408
 409         dbg("%s - port %d", __func__, port->number);
 410         if (!usb_get_intfdata(port->serial->interface))
 411                 return -ENODEV;
 412
 413         spin_lock_irqsave(&priv->lock, flags);
 414         if (priv->rts)
 415                 result |= TIOCM_RTS;
 416         if (priv->cts)
 417                 result |= TIOCM_CTS;
 418         spin_unlock_irqrestore(&priv->lock, flags);
 419
 420         dbg("%s - %x", __func__, result);
 421         return result;
 422 }
 423
 424 static int opticon_tiocmset(struct tty_struct *tty,
 425                            unsigned int set, unsigned int clear)
 426 {
 427         struct usb_serial_port *port = tty->driver_data;
 428         struct opticon_private *priv = usb_get_serial_data(port->serial);
 429         unsigned long flags;
 430         bool rts;
 431         bool changed = false;
 432
 433         if (!usb_get_intfdata(port->serial->interface))
 434                 return -ENODEV;
 435         /* We only support RTS so we only handle that */
 436         spin_lock_irqsave(&priv->lock, flags);
 437
 438         rts = priv->rts;
 439         if (set & TIOCM_RTS)
 440                 priv->rts = true;
 441         if (clear & TIOCM_RTS)
 442                 priv->rts = false;
 443         changed = rts ^ priv->rts;
 444         spin_unlock_irqrestore(&priv->lock, flags);
 445
 446         if (!changed)
 447                 return 0;
 448
 449         /* Send the new RTS state to the connected device */
 450         return send_control_msg(port, CONTROL_RTS, !rts);
 451 }
 452
 453 static int get_serial_info(struct opticon_private *priv,
 454                            struct serial_struct __user *serial)
 455 {
 456         struct serial_struct tmp;
 457
 458         if (!serial)
 459                 return -EFAULT;
 460
 461         memset(&tmp, 0x00, sizeof(tmp));
 462
 463         /* fake emulate a 16550 uart to make userspace code happy */
 464         tmp.type                = PORT_16550A;
 465         tmp.line                = priv->serial->minor;
 466         tmp.port                = 0;
 467         tmp.irq                 = 0;
 468         tmp.flags               = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
 469         tmp.xmit_fifo_size      = 1024;
 470         tmp.baud_base           = 9600;
 471         tmp.close_delay         = 5*HZ;
 472         tmp.closing_wait        = 30*HZ;
 473
 474         if (copy_to_user(serial, &tmp, sizeof(*serial)))
 475                 return -EFAULT;
 476         return 0;
 477 }
 478
 479 static int opticon_ioctl(struct tty_struct *tty,
 480                          unsigned int cmd, unsigned long arg)
 481 {
 482         struct usb_serial_port *port = tty->driver_data;
 483         struct opticon_private *priv = usb_get_serial_data(port->serial);
 484
 485         dbg("%s - port %d, cmd = 0x%x", __func__, port->number, cmd);
 486
 487         switch (cmd) {
 488         case TIOCGSERIAL:
 489                 return get_serial_info(priv,
 490                                        (struct serial_struct __user *)arg);
 491         }
 492
 493         return -ENOIOCTLCMD;
 494 }
 495
 496 static int opticon_startup(struct usb_serial *serial)
 497 {
 498         struct opticon_private *priv;
 499         struct usb_host_interface *intf;
 500         int i;
 501         int retval = -ENOMEM;
 502         bool bulk_in_found = false;
 503
 504         /* create our private serial structure */
 505         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 506         if (priv == NULL) {
 507                 dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__);
 508                 return -ENOMEM;
 509         }
 510         spin_lock_init(&priv->lock);
 511         priv->serial = serial;
 512         priv->port = serial->port[0];
 513         priv->udev = serial->dev;
 514         priv->outstanding_urbs = 0;     /* Init the outstanding urbs */
 515
 516         /* find our bulk endpoint */
 517         intf = serial->interface->altsetting;
 518         for (i = 0; i < intf->desc.bNumEndpoints; ++i) {
 519                 struct usb_endpoint_descriptor *endpoint;
 520
 521                 endpoint = &intf->endpoint[i].desc;
 522                 if (!usb_endpoint_is_bulk_in(endpoint))
 523                         continue;
 524
 525                 priv->bulk_read_urb = usb_alloc_urb(0, GFP_KERNEL);
 526                 if (!priv->bulk_read_urb) {
 527                         dev_err(&priv->udev->dev, "out of memory\n");
 528                         goto error;
 529                 }
 530
 531                 priv->buffer_size = usb_endpoint_maxp(endpoint) * 2;
 532                 priv->bulk_in_buffer = kmalloc(priv->buffer_size, GFP_KERNEL);
 533                 if (!priv->bulk_in_buffer) {
 534                         dev_err(&priv->udev->dev, "out of memory\n");
 535                         goto error;
 536                 }
 537
 538                 priv->bulk_address = endpoint->bEndpointAddress;
 539
 540                 bulk_in_found = true;
 541                 break;
 542                 }
 543
 544         if (!bulk_in_found) {
 545                 dev_err(&priv->udev->dev,
 546                         "Error - the proper endpoints were not found!\n");
 547                 goto error;
 548         }
 549
 550         usb_set_serial_data(serial, priv);
 551         return 0;
 552
 553 error:
 554         usb_free_urb(priv->bulk_read_urb);
 555         kfree(priv->bulk_in_buffer);
 556         kfree(priv);
 557         return retval;
 558 }
 559
 560 static void opticon_disconnect(struct usb_serial *serial)
 561 {
 562         struct opticon_private *priv = usb_get_serial_data(serial);
 563
 564         dbg("%s", __func__);
 565
 566         usb_kill_urb(priv->bulk_read_urb);
 567         usb_free_urb(priv->bulk_read_urb);
 568 }
 569
 570 static void opticon_release(struct usb_serial *serial)
 571 {
 572         struct opticon_private *priv = usb_get_serial_data(serial);
 573
 574         dbg("%s", __func__);
 575
 576         kfree(priv->bulk_in_buffer);
 577         kfree(priv);
 578 }
 579
 580 static int opticon_suspend(struct usb_interface *intf, pm_message_t message)
 581 {
 582         struct usb_serial *serial = usb_get_intfdata(intf);
 583         struct opticon_private *priv = usb_get_serial_data(serial);
 584
 585         usb_kill_urb(priv->bulk_read_urb);
 586         return 0;
 587 }
 588
 589 static int opticon_resume(struct usb_interface *intf)
 590 {
 591         struct usb_serial *serial = usb_get_intfdata(intf);
 592         struct opticon_private *priv = usb_get_serial_data(serial);
 593         struct usb_serial_port *port = serial->port[0];
 594         int result;
 595
 596         mutex_lock(&port->port.mutex);
 597         /* This is protected by the port mutex against close/open */
 598         if (test_bit(ASYNCB_INITIALIZED, &port->port.flags))
 599                 result = usb_submit_urb(priv->bulk_read_urb, GFP_NOIO);
 600         else
 601                 result = 0;
 602         mutex_unlock(&port->port.mutex);
 603         return result;
 604 }
 605
 606 static struct usb_driver opticon_driver = {
 607         .name =         "opticon",
 608         .probe =        usb_serial_probe,
 609         .disconnect =   usb_serial_disconnect,
 610         .suspend =      opticon_suspend,
 611         .resume =       opticon_resume,
 612         .id_table =     id_table,
 613         .no_dynamic_id =        1,
 614 };
 615
 616 static struct usb_serial_driver opticon_device = {
 617         .driver = {
 618                 .owner =        THIS_MODULE,
 619                 .name =         "opticon",
 620         },
 621         .id_table =             id_table,
 622         .usb_driver =           &opticon_driver,
 623         .num_ports =            1,
 624         .attach =               opticon_startup,
 625         .open =                 opticon_open,
 626         .close =                opticon_close,
 627         .write =                opticon_write,
 628         .write_room =           opticon_write_room,
 629         .disconnect =           opticon_disconnect,
 630         .release =              opticon_release,
 631         .throttle =             opticon_throttle,
 632         .unthrottle =           opticon_unthrottle,
 633         .ioctl =                opticon_ioctl,
 634         .tiocmget =             opticon_tiocmget,
 635         .tiocmset =             opticon_tiocmset,
 636 };
 637
 638 static int __init opticon_init(void)
 639 {
 640         int retval;
 641
 642         retval = usb_serial_register(&opticon_device);
 643         if (retval)
 644                 return retval;
 645         retval = usb_register(&opticon_driver);
 646         if (retval)
 647                 usb_serial_deregister(&opticon_device);
 648         return retval;
 649 }
 650
 651 static void __exit opticon_exit(void)
 652 {
 653         usb_deregister(&opticon_driver);
 654         usb_serial_deregister(&opticon_device);
 655 }
 656
 657 module_init(opticon_init);
 658 module_exit(opticon_exit);
 659 MODULE_DESCRIPTION(DRIVER_DESC);
 660 MODULE_LICENSE("GPL");
 661
 662 module_param(debug, bool, S_IRUGO | S_IWUSR);
 663 MODULE_PARM_DESC(debug, "Debug enabled or not");