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