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