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