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