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