drivers/usb/serial/opticon.c

   1 /*
   2  * Opticon USB barcode to serial driver
   3  *
   4  * Copyright (C) 2008 - 2009 Greg Kroah-Hartman <gregkh@suse.de>
   5  * Copyright (C) 2008 - 2009 Novell Inc.
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License version
   9  *      2 as published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/init.h>
  14 #include <linux/tty.h>
  15 #include <linux/tty_driver.h>
  16 #include <linux/tty_flip.h>
  17 #include <linux/serial.h>
  18 #include <linux/module.h>
  19 #include <linux/usb.h>
  20 #include <linux/usb/serial.h>
  21 #include <linux/uaccess.h>
  22
  23 static int debug;
  24
  25 static struct usb_device_id id_table[] = {
  26         { USB_DEVICE(0x065a, 0x0009) },
  27         { },
  28 };
  29 MODULE_DEVICE_TABLE(usb, id_table);
  30
  31 /* This structure holds all of the individual device information */
  32 struct opticon_private {
  33         struct usb_device *udev;
  34         struct usb_serial *serial;
  35         struct usb_serial_port *port;
  36         unsigned char *bulk_in_buffer;
  37         struct urb *bulk_read_urb;
  38         int buffer_size;
  39         u8 bulk_address;
  40         spinlock_t lock;        /* protects the following flags */
  41         bool throttled;
  42         bool actually_throttled;
  43         bool rts;
  44         int outstanding_urbs;
  45 };
  46
  47 /* max number of write urbs in flight */
  48 #define URB_UPPER_LIMIT 4
  49
  50 static void opticon_bulk_callback(struct urb *urb)
  51 {
  52         struct opticon_private *priv = urb->context;
  53         unsigned char *data = urb->transfer_buffer;
  54         struct usb_serial_port *port = priv->port;
  55         int status = urb->status;
  56         struct tty_struct *tty;
  57         int result;
  58         int available_room = 0;
  59         int data_length;
  60
  61         dbg("%s - port %d", __func__, port->number);
  62
  63         switch (status) {
  64         case 0:
  65                 /* success */
  66                 break;
  67         case -ECONNRESET:
  68         case -ENOENT:
  69         case -ESHUTDOWN:
  70                 /* this urb is terminated, clean up */
  71                 dbg("%s - urb shutting down with status: %d",
  72                     __func__, status);
  73                 return;
  74         default:
  75                 dbg("%s - nonzero urb status received: %d",
  76                     __func__, status);
  77                 goto exit;
  78         }
  79
  80         usb_serial_debug_data(debug, &port->dev, __func__, urb->actual_length,
  81                               data);
  82
  83         if (urb->actual_length > 2) {
  84                 data_length = urb->actual_length - 2;
  85
  86                 /*
  87                  * Data from the device comes with a 2 byte header:
  88                  *
  89                  * <0x00><0x00>data...
  90                  *      This is real data to be sent to the tty layer
  91                  * <0x00><0x01)level
  92                  *      This is a RTS level change, the third byte is the RTS
  93                  *      value (0 for low, 1 for high).
  94                  */
  95                 if ((data[0] == 0x00) && (data[1] == 0x00)) {
  96                         /* real data, send it to the tty layer */
  97                         tty = tty_port_tty_get(&port->port);
  98                         if (tty) {
  99                                 available_room = tty_buffer_request_room(tty,
 100                                                                 data_length);
 101                                 if (available_room) {
 102                                         tty_insert_flip_string(tty, data,
 103                                                                available_room);
 104                                         tty_flip_buffer_push(tty);
 105                                 }
 106                                 tty_kref_put(tty);
 107                         }
 108                 } else {
 109                         if ((data[0] == 0x00) && (data[1] == 0x01)) {
 110                                 if (data[2] == 0x00)
 111                                         priv->rts = false;
 112                                 else
 113                                         priv->rts = true;
 114                         } else {
 115                         dev_dbg(&priv->udev->dev,
 116                                 "Unknown data packet received from the device:"
 117                                 " %2x %2x\n",
 118                                 data[0], data[1]);
 119                         }
 120                 }
 121         } else {
 122                 dev_dbg(&priv->udev->dev,
 123                         "Improper ammount of data received from the device, "
 124                         "%d bytes", urb->actual_length);
 125         }
 126
 127 exit:
 128         spin_lock(&priv->lock);
 129
 130         /* Continue trying to always read if we should */
 131         if (!priv->throttled) {
 132                 usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
 133                                   usb_rcvbulkpipe(priv->udev,
 134                                                   priv->bulk_address),
 135                                   priv->bulk_in_buffer, priv->buffer_size,
 136                                   opticon_bulk_callback, priv);
 137                 result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
 138                 if (result)
 139                         dev_err(&port->dev,
 140                             "%s - failed resubmitting read urb, error %d\n",
 141                                                         __func__, result);
 142         } else
 143                 priv->actually_throttled = true;
 144         spin_unlock(&priv->lock);
 145 }
 146
 147 static int opticon_open(struct tty_struct *tty, struct usb_serial_port *port)
 148 {
 149         struct opticon_private *priv = usb_get_serial_data(port->serial);
 150         unsigned long flags;
 151         int result = 0;
 152
 153         dbg("%s - port %d", __func__, port->number);
 154
 155         spin_lock_irqsave(&priv->lock, flags);
 156         priv->throttled = false;
 157         priv->actually_throttled = false;
 158         priv->port = port;
 159         spin_unlock_irqrestore(&priv->lock, flags);
 160
 161         /* Start reading from the device */
 162         usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
 163                           usb_rcvbulkpipe(priv->udev,
 164                                           priv->bulk_address),
 165                           priv->bulk_in_buffer, priv->buffer_size,
 166                           opticon_bulk_callback, priv);
 167         result = usb_submit_urb(priv->bulk_read_urb, GFP_KERNEL);
 168         if (result)
 169                 dev_err(&port->dev,
 170                         "%s - failed resubmitting read urb, error %d\n",
 171                         __func__, result);
 172         return result;
 173 }
 174
 175 static void opticon_close(struct usb_serial_port *port)
 176 {
 177         struct opticon_private *priv = usb_get_serial_data(port->serial);
 178
 179         dbg("%s - port %d", __func__, port->number);
 180
 181         /* shutdown our urbs */
 182         usb_kill_urb(priv->bulk_read_urb);
 183 }
 184
 185 static void opticon_write_bulk_callback(struct urb *urb)
 186 {
 187         struct opticon_private *priv = urb->context;
 188         int status = urb->status;
 189         unsigned long flags;
 190
 191         /* free up the transfer buffer, as usb_free_urb() does not do this */
 192         kfree(urb->transfer_buffer);
 193
 194         if (status)
 195                 dbg("%s - nonzero write bulk status received: %d",
 196                     __func__, status);
 197
 198         spin_lock_irqsave(&priv->lock, flags);
 199         --priv->outstanding_urbs;
 200         spin_unlock_irqrestore(&priv->lock, flags);
 201
 202         usb_serial_port_softint(priv->port);
 203 }
 204
 205 static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
 206                          const unsigned char *buf, int count)
 207 {
 208         struct opticon_private *priv = usb_get_serial_data(port->serial);
 209         struct usb_serial *serial = port->serial;
 210         struct urb *urb;
 211         unsigned char *buffer;
 212         unsigned long flags;
 213         int status;
 214
 215         dbg("%s - port %d", __func__, port->number);
 216
 217         spin_lock_irqsave(&priv->lock, flags);
 218         if (priv->outstanding_urbs > URB_UPPER_LIMIT) {
 219                 spin_unlock_irqrestore(&priv->lock, flags);
 220                 dbg("%s - write limit hit\n", __func__);
 221                 return 0;
 222         }
 223         priv->outstanding_urbs++;
 224         spin_unlock_irqrestore(&priv->lock, flags);
 225
 226         buffer = kmalloc(count, GFP_ATOMIC);
 227         if (!buffer) {
 228                 dev_err(&port->dev, "out of memory\n");
 229                 count = -ENOMEM;
 230                 goto error_no_buffer;
 231         }
 232
 233         urb = usb_alloc_urb(0, GFP_ATOMIC);
 234         if (!urb) {
 235                 dev_err(&port->dev, "no more free urbs\n");
 236                 count = -ENOMEM;
 237                 goto error_no_urb;
 238         }
 239
 240         memcpy(buffer, buf, count);
 241
 242         usb_serial_debug_data(debug, &port->dev, __func__, count, buffer);
 243
 244         usb_fill_bulk_urb(urb, serial->dev,
 245                           usb_sndbulkpipe(serial->dev,
 246                                           port->bulk_out_endpointAddress),
 247                           buffer, count, opticon_write_bulk_callback, priv);
 248
 249         /* send it down the pipe */
 250         status = usb_submit_urb(urb, GFP_ATOMIC);
 251         if (status) {
 252                 dev_err(&port->dev,
 253                    "%s - usb_submit_urb(write bulk) failed with status = %d\n",
 254                                                         __func__, status);
 255                 count = status;
 256                 goto error;
 257         }
 258
 259         /* we are done with this urb, so let the host driver
 260          * really free it when it is finished with it */
 261         usb_free_urb(urb);
 262
 263         return count;
 264 error:
 265         usb_free_urb(urb);
 266 error_no_urb:
 267         kfree(buffer);
 268 error_no_buffer:
 269         spin_lock_irqsave(&priv->lock, flags);
 270         --priv->outstanding_urbs;
 271         spin_unlock_irqrestore(&priv->lock, flags);
 272         return count;
 273 }
 274
 275 static int opticon_write_room(struct tty_struct *tty)
 276 {
 277         struct usb_serial_port *port = tty->driver_data;
 278         struct opticon_private *priv = usb_get_serial_data(port->serial);
 279         unsigned long flags;
 280
 281         dbg("%s - port %d", __func__, port->number);
 282
 283         /*
 284          * We really can take almost anything the user throws at us
 285          * but let's pick a nice big number to tell the tty
 286          * layer that we have lots of free space, unless we don't.
 287          */
 288         spin_lock_irqsave(&priv->lock, flags);
 289         if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) {
 290                 spin_unlock_irqrestore(&priv->lock, flags);
 291                 dbg("%s - write limit hit\n", __func__);
 292                 return 0;
 293         }
 294         spin_unlock_irqrestore(&priv->lock, flags);
 295
 296         return 2048;
 297 }
 298
 299 static void opticon_throttle(struct tty_struct *tty)
 300 {
 301         struct usb_serial_port *port = tty->driver_data;
 302         struct opticon_private *priv = usb_get_serial_data(port->serial);
 303         unsigned long flags;
 304
 305         dbg("%s - port %d", __func__, port->number);
 306         spin_lock_irqsave(&priv->lock, flags);
 307         priv->throttled = true;
 308         spin_unlock_irqrestore(&priv->lock, flags);
 309 }
 310
 311
 312 static void opticon_unthrottle(struct tty_struct *tty)
 313 {
 314         struct usb_serial_port *port = tty->driver_data;
 315         struct opticon_private *priv = usb_get_serial_data(port->serial);
 316         unsigned long flags;
 317         int result, was_throttled;
 318
 319         dbg("%s - port %d", __func__, port->number);
 320
 321         spin_lock_irqsave(&priv->lock, flags);
 322         priv->throttled = false;
 323         was_throttled = priv->actually_throttled;
 324         priv->actually_throttled = false;
 325         spin_unlock_irqrestore(&priv->lock, flags);
 326
 327         priv->bulk_read_urb->dev = port->serial->dev;
 328         if (was_throttled) {
 329                 result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC);
 330                 if (result)
 331                         dev_err(&port->dev,
 332                                 "%s - failed submitting read urb, error %d\n",
 333                                                         __func__, result);
 334         }
 335 }
 336
 337 static int opticon_tiocmget(struct tty_struct *tty, struct file *file)
 338 {
 339         struct usb_serial_port *port = tty->driver_data;
 340         struct opticon_private *priv = usb_get_serial_data(port->serial);
 341         unsigned long flags;
 342         int result = 0;
 343
 344         dbg("%s - port %d", __func__, port->number);
 345
 346         spin_lock_irqsave(&priv->lock, flags);
 347         if (priv->rts)
 348                 result = TIOCM_RTS;
 349         spin_unlock_irqrestore(&priv->lock, flags);
 350
 351         dbg("%s - %x", __func__, result);
 352         return result;
 353 }
 354
 355 static int get_serial_info(struct opticon_private *priv,
 356                            struct serial_struct __user *serial)
 357 {
 358         struct serial_struct tmp;
 359
 360         if (!serial)
 361                 return -EFAULT;
 362
 363         memset(&tmp, 0x00, sizeof(tmp));
 364
 365         /* fake emulate a 16550 uart to make userspace code happy */
 366         tmp.type                = PORT_16550A;
 367         tmp.line                = priv->serial->minor;
 368         tmp.port                = 0;
 369         tmp.irq                 = 0;
 370         tmp.flags               = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
 371         tmp.xmit_fifo_size      = 1024;
 372         tmp.baud_base           = 9600;
 373         tmp.close_delay         = 5*HZ;
 374         tmp.closing_wait        = 30*HZ;
 375
 376         if (copy_to_user(serial, &tmp, sizeof(*serial)))
 377                 return -EFAULT;
 378         return 0;
 379 }
 380
 381 static int opticon_ioctl(struct tty_struct *tty, struct file *file,
 382                          unsigned int cmd, unsigned long arg)
 383 {
 384         struct usb_serial_port *port = tty->driver_data;
 385         struct opticon_private *priv = usb_get_serial_data(port->serial);
 386
 387         dbg("%s - port %d, cmd = 0x%x", __func__, port->number, cmd);
 388
 389         switch (cmd) {
 390         case TIOCGSERIAL:
 391                 return get_serial_info(priv,
 392                                        (struct serial_struct __user *)arg);
 393         }
 394
 395         return -ENOIOCTLCMD;
 396 }
 397
 398 static int opticon_startup(struct usb_serial *serial)
 399 {
 400         struct opticon_private *priv;
 401         struct usb_host_interface *intf;
 402         int i;
 403         int retval = -ENOMEM;
 404         bool bulk_in_found = false;
 405
 406         /* create our private serial structure */
 407         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 408         if (priv == NULL) {
 409                 dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__);
 410                 return -ENOMEM;
 411         }
 412         spin_lock_init(&priv->lock);
 413         priv->serial = serial;
 414         priv->port = serial->port[0];
 415         priv->udev = serial->dev;
 416
 417         /* find our bulk endpoint */
 418         intf = serial->interface->altsetting;
 419         for (i = 0; i < intf->desc.bNumEndpoints; ++i) {
 420                 struct usb_endpoint_descriptor *endpoint;
 421
 422                 endpoint = &intf->endpoint[i].desc;
 423                 if (!usb_endpoint_is_bulk_in(endpoint))
 424                         continue;
 425
 426                 priv->bulk_read_urb = usb_alloc_urb(0, GFP_KERNEL);
 427                 if (!priv->bulk_read_urb) {
 428                         dev_err(&priv->udev->dev, "out of memory\n");
 429                         goto error;
 430                 }
 431
 432                 priv->buffer_size = le16_to_cpu(endpoint->wMaxPacketSize) * 2;
 433                 priv->bulk_in_buffer = kmalloc(priv->buffer_size, GFP_KERNEL);
 434                 if (!priv->bulk_in_buffer) {
 435                         dev_err(&priv->udev->dev, "out of memory\n");
 436                         goto error;
 437                 }
 438
 439                 priv->bulk_address = endpoint->bEndpointAddress;
 440
 441                 /* set up our bulk urb */
 442                 usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
 443                                   usb_rcvbulkpipe(priv->udev,
 444                                                   endpoint->bEndpointAddress),
 445                                   priv->bulk_in_buffer, priv->buffer_size,
 446                                   opticon_bulk_callback, priv);
 447
 448                 bulk_in_found = true;
 449                 break;
 450                 }
 451
 452         if (!bulk_in_found) {
 453                 dev_err(&priv->udev->dev,
 454                         "Error - the proper endpoints were not found!\n");
 455                 goto error;
 456         }
 457
 458         usb_set_serial_data(serial, priv);
 459         return 0;
 460
 461 error:
 462         usb_free_urb(priv->bulk_read_urb);
 463         kfree(priv->bulk_in_buffer);
 464         kfree(priv);
 465         return retval;
 466 }
 467
 468 static void opticon_disconnect(struct usb_serial *serial)
 469 {
 470         struct opticon_private *priv = usb_get_serial_data(serial);
 471
 472         dbg("%s", __func__);
 473
 474         usb_kill_urb(priv->bulk_read_urb);
 475         usb_free_urb(priv->bulk_read_urb);
 476 }
 477
 478 static void opticon_release(struct usb_serial *serial)
 479 {
 480         struct opticon_private *priv = usb_get_serial_data(serial);
 481
 482         dbg("%s", __func__);
 483
 484         kfree(priv->bulk_in_buffer);
 485         kfree(priv);
 486 }
 487
 488 static int opticon_suspend(struct usb_interface *intf, pm_message_t message)
 489 {
 490         struct usb_serial *serial = usb_get_intfdata(intf);
 491         struct opticon_private *priv = usb_get_serial_data(serial);
 492
 493         usb_kill_urb(priv->bulk_read_urb);
 494         return 0;
 495 }
 496
 497 static int opticon_resume(struct usb_interface *intf)
 498 {
 499         struct usb_serial *serial = usb_get_intfdata(intf);
 500         struct opticon_private *priv = usb_get_serial_data(serial);
 501         struct usb_serial_port *port = serial->port[0];
 502         int result;
 503
 504         mutex_lock(&port->mutex);
 505         if (port->port.count)
 506                 result = usb_submit_urb(priv->bulk_read_urb, GFP_NOIO);
 507         else
 508                 result = 0;
 509         mutex_unlock(&port->mutex);
 510         return result;
 511 }
 512
 513 static struct usb_driver opticon_driver = {
 514         .name =         "opticon",
 515         .probe =        usb_serial_probe,
 516         .disconnect =   usb_serial_disconnect,
 517         .suspend =      opticon_suspend,
 518         .resume =       opticon_resume,
 519         .id_table =     id_table,
 520         .no_dynamic_id =        1,
 521 };
 522
 523 static struct usb_serial_driver opticon_device = {
 524         .driver = {
 525                 .owner =        THIS_MODULE,
 526                 .name =         "opticon",
 527         },
 528         .id_table =             id_table,
 529         .usb_driver =           &opticon_driver,
 530         .num_ports =            1,
 531         .attach =               opticon_startup,
 532         .open =                 opticon_open,
 533         .close =                opticon_close,
 534         .write =                opticon_write,
 535         .write_room =           opticon_write_room,
 536         .disconnect =           opticon_disconnect,
 537         .release =              opticon_release,
 538         .throttle =             opticon_throttle,
 539         .unthrottle =           opticon_unthrottle,
 540         .ioctl =                opticon_ioctl,
 541         .tiocmget =             opticon_tiocmget,
 542 };
 543
 544 static int __init opticon_init(void)
 545 {
 546         int retval;
 547
 548         retval = usb_serial_register(&opticon_device);
 549         if (retval)
 550                 return retval;
 551         retval = usb_register(&opticon_driver);
 552         if (retval)
 553                 usb_serial_deregister(&opticon_device);
 554         return retval;
 555 }
 556
 557 static void __exit opticon_exit(void)
 558 {
 559         usb_deregister(&opticon_driver);
 560         usb_serial_deregister(&opticon_device);
 561 }
 562
 563 module_init(opticon_init);
 564 module_exit(opticon_exit);
 565 MODULE_LICENSE("GPL");
 566
 567 module_param(debug, bool, S_IRUGO | S_IWUSR);
 568 MODULE_PARM_DESC(debug, "Debug enabled or not");