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/slab.h>
  17 #include <linux/tty_flip.h>
  18 #include <linux/serial.h>
  19 #include <linux/module.h>
  20 #include <linux/usb.h>
  21 #include <linux/usb/serial.h>
  22 #include <linux/uaccess.h>
  23
  24 static int debug;
  25
  26 static const struct usb_device_id id_table[] = {
  27         { USB_DEVICE(0x065a, 0x0009) },
  28         { },
  29 };
  30 MODULE_DEVICE_TABLE(usb, id_table);
  31
  32 /* This structure holds all of the individual device information */
  33 struct opticon_private {
  34         struct usb_device *udev;
  35         struct usb_serial *serial;
  36         struct usb_serial_port *port;
  37         unsigned char *bulk_in_buffer;
  38         struct urb *bulk_read_urb;
  39         int buffer_size;
  40         u8 bulk_address;
  41         spinlock_t lock;        /* protects the following flags */
  42         bool throttled;
  43         bool actually_throttled;
  44         bool rts;
  45         int outstanding_urbs;
  46 };
  47
  48 /* max number of write urbs in flight */
  49 #define URB_UPPER_LIMIT 4
  50
  51 static void opticon_bulk_callback(struct urb *urb)
  52 {
  53         struct opticon_private *priv = urb->context;
  54         unsigned char *data = urb->transfer_buffer;
  55         struct usb_serial_port *port = priv->port;
  56         int status = urb->status;
  57         struct tty_struct *tty;
  58         int result;
  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                                 tty_insert_flip_string(tty, data + 2,
 100                                                        data_length);
 101                                 tty_flip_buffer_push(tty);
 102                                 tty_kref_put(tty);
 103                         }
 104                 } else {
 105                         if ((data[0] == 0x00) && (data[1] == 0x01)) {
 106                                 if (data[2] == 0x00)
 107                                         priv->rts = false;
 108                                 else
 109                                         priv->rts = true;
 110                         } else {
 111                                 dev_dbg(&priv->udev->dev,
 112                                         "Unknown data packet received from the device:"
 113                                         " %2x %2x\n",
 114                                         data[0], data[1]);
 115                         }
 116                 }
 117         } else {
 118                 dev_dbg(&priv->udev->dev,
 119                         "Improper amount of data received from the device, "
 120                         "%d bytes", urb->actual_length);
 121         }
 122
 123 exit:
 124         spin_lock(&priv->lock);
 125
 126         /* Continue trying to always read if we should */
 127         if (!priv->throttled) {
 128                 usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
 129                                   usb_rcvbulkpipe(priv->udev,
 130                                                   priv->bulk_address),
 131                                   priv->bulk_in_buffer, priv->buffer_size,
 132                                   opticon_bulk_callback, priv);
 133                 result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC);
 134                 if (result)
 135                         dev_err(&port->dev,
 136                             "%s - failed resubmitting read urb, error %d\n",
 137                                                         __func__, result);
 138         } else
 139                 priv->actually_throttled = true;
 140         spin_unlock(&priv->lock);
 141 }
 142
 143 static int opticon_open(struct tty_struct *tty, struct usb_serial_port *port)
 144 {
 145         struct opticon_private *priv = usb_get_serial_data(port->serial);
 146         unsigned long flags;
 147         int result = 0;
 148
 149         dbg("%s - port %d", __func__, port->number);
 150
 151         spin_lock_irqsave(&priv->lock, flags);
 152         priv->throttled = false;
 153         priv->actually_throttled = false;
 154         priv->port = port;
 155         spin_unlock_irqrestore(&priv->lock, flags);
 156
 157         /* Start reading from the device */
 158         usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
 159                           usb_rcvbulkpipe(priv->udev,
 160                                           priv->bulk_address),
 161                           priv->bulk_in_buffer, priv->buffer_size,
 162                           opticon_bulk_callback, priv);
 163         result = usb_submit_urb(priv->bulk_read_urb, GFP_KERNEL);
 164         if (result)
 165                 dev_err(&port->dev,
 166                         "%s - failed resubmitting read urb, error %d\n",
 167                         __func__, result);
 168         return result;
 169 }
 170
 171 static void opticon_close(struct usb_serial_port *port)
 172 {
 173         struct opticon_private *priv = usb_get_serial_data(port->serial);
 174
 175         dbg("%s - port %d", __func__, port->number);
 176
 177         /* shutdown our urbs */
 178         usb_kill_urb(priv->bulk_read_urb);
 179 }
 180
 181 static void opticon_write_bulk_callback(struct urb *urb)
 182 {
 183         struct opticon_private *priv = urb->context;
 184         int status = urb->status;
 185         unsigned long flags;
 186
 187         /* free up the transfer buffer, as usb_free_urb() does not do this */
 188         kfree(urb->transfer_buffer);
 189
 190         /* setup packet may be set if we're using it for writing */
 191         kfree(urb->setup_packet);
 192
 193         if (status)
 194                 dbg("%s - nonzero write bulk status received: %d",
 195                     __func__, status);
 196
 197         spin_lock_irqsave(&priv->lock, flags);
 198         --priv->outstanding_urbs;
 199         spin_unlock_irqrestore(&priv->lock, flags);
 200
 201         usb_serial_port_softint(priv->port);
 202 }
 203
 204 static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
 205                          const unsigned char *buf, int count)
 206 {
 207         struct opticon_private *priv = usb_get_serial_data(port->serial);
 208         struct usb_serial *serial = port->serial;
 209         struct urb *urb;
 210         unsigned char *buffer;
 211         unsigned long flags;
 212         int status;
 213
 214         dbg("%s - port %d", __func__, port->number);
 215
 216         spin_lock_irqsave(&priv->lock, flags);
 217         if (priv->outstanding_urbs > URB_UPPER_LIMIT) {
 218                 spin_unlock_irqrestore(&priv->lock, flags);
 219                 dbg("%s - write limit hit", __func__);
 220                 return 0;
 221         }
 222         priv->outstanding_urbs++;
 223         spin_unlock_irqrestore(&priv->lock, flags);
 224
 225         buffer = kmalloc(count, GFP_ATOMIC);
 226         if (!buffer) {
 227                 dev_err(&port->dev, "out of memory\n");
 228                 count = -ENOMEM;
 229                 goto error_no_buffer;
 230         }
 231
 232         urb = usb_alloc_urb(0, GFP_ATOMIC);
 233         if (!urb) {
 234                 dev_err(&port->dev, "no more free urbs\n");
 235                 count = -ENOMEM;
 236                 goto error_no_urb;
 237         }
 238
 239         memcpy(buffer, buf, count);
 240
 241         usb_serial_debug_data(debug, &port->dev, __func__, count, buffer);
 242
 243         if (port->bulk_out_endpointAddress) {
 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         } else {
 249                 struct usb_ctrlrequest *dr;
 250
 251                 dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO);
 252                 if (!dr)
 253                         return -ENOMEM;
 254
 255                 dr->bRequestType = USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT;
 256                 dr->bRequest = 0x01;
 257                 dr->wValue = 0;
 258                 dr->wIndex = 0;
 259                 dr->wLength = cpu_to_le16(count);
 260
 261                 usb_fill_control_urb(urb, serial->dev,
 262                         usb_sndctrlpipe(serial->dev, 0),
 263                         (unsigned char *)dr, buffer, count,
 264                         opticon_write_bulk_callback, priv);
 265         }
 266
 267         /* send it down the pipe */
 268         status = usb_submit_urb(urb, GFP_ATOMIC);
 269         if (status) {
 270                 dev_err(&port->dev,
 271                    "%s - usb_submit_urb(write bulk) failed with status = %d\n",
 272                                                         __func__, status);
 273                 count = status;
 274                 goto error;
 275         }
 276
 277         /* we are done with this urb, so let the host driver
 278          * really free it when it is finished with it */
 279         usb_free_urb(urb);
 280
 281         return count;
 282 error:
 283         usb_free_urb(urb);
 284 error_no_urb:
 285         kfree(buffer);
 286 error_no_buffer:
 287         spin_lock_irqsave(&priv->lock, flags);
 288         --priv->outstanding_urbs;
 289         spin_unlock_irqrestore(&priv->lock, flags);
 290         return count;
 291 }
 292
 293 static int opticon_write_room(struct tty_struct *tty)
 294 {
 295         struct usb_serial_port *port = tty->driver_data;
 296         struct opticon_private *priv = usb_get_serial_data(port->serial);
 297         unsigned long flags;
 298
 299         dbg("%s - port %d", __func__, port->number);
 300
 301         /*
 302          * We really can take almost anything the user throws at us
 303          * but let's pick a nice big number to tell the tty
 304          * layer that we have lots of free space, unless we don't.
 305          */
 306         spin_lock_irqsave(&priv->lock, flags);
 307         if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) {
 308                 spin_unlock_irqrestore(&priv->lock, flags);
 309                 dbg("%s - write limit hit", __func__);
 310                 return 0;
 311         }
 312         spin_unlock_irqrestore(&priv->lock, flags);
 313
 314         return 2048;
 315 }
 316
 317 static void opticon_throttle(struct tty_struct *tty)
 318 {
 319         struct usb_serial_port *port = tty->driver_data;
 320         struct opticon_private *priv = usb_get_serial_data(port->serial);
 321         unsigned long flags;
 322
 323         dbg("%s - port %d", __func__, port->number);
 324         spin_lock_irqsave(&priv->lock, flags);
 325         priv->throttled = true;
 326         spin_unlock_irqrestore(&priv->lock, flags);
 327 }
 328
 329
 330 static void opticon_unthrottle(struct tty_struct *tty)
 331 {
 332         struct usb_serial_port *port = tty->driver_data;
 333         struct opticon_private *priv = usb_get_serial_data(port->serial);
 334         unsigned long flags;
 335         int result, was_throttled;
 336
 337         dbg("%s - port %d", __func__, port->number);
 338
 339         spin_lock_irqsave(&priv->lock, flags);
 340         priv->throttled = false;
 341         was_throttled = priv->actually_throttled;
 342         priv->actually_throttled = false;
 343         spin_unlock_irqrestore(&priv->lock, flags);
 344
 345         priv->bulk_read_urb->dev = port->serial->dev;
 346         if (was_throttled) {
 347                 result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC);
 348                 if (result)
 349                         dev_err(&port->dev,
 350                                 "%s - failed submitting read urb, error %d\n",
 351                                                         __func__, result);
 352         }
 353 }
 354
 355 static int opticon_tiocmget(struct tty_struct *tty, struct file *file)
 356 {
 357         struct usb_serial_port *port = tty->driver_data;
 358         struct opticon_private *priv = usb_get_serial_data(port->serial);
 359         unsigned long flags;
 360         int result = 0;
 361
 362         dbg("%s - port %d", __func__, port->number);
 363
 364         spin_lock_irqsave(&priv->lock, flags);
 365         if (priv->rts)
 366                 result = TIOCM_RTS;
 367         spin_unlock_irqrestore(&priv->lock, flags);
 368
 369         dbg("%s - %x", __func__, result);
 370         return result;
 371 }
 372
 373 static int get_serial_info(struct opticon_private *priv,
 374                            struct serial_struct __user *serial)
 375 {
 376         struct serial_struct tmp;
 377
 378         if (!serial)
 379                 return -EFAULT;
 380
 381         memset(&tmp, 0x00, sizeof(tmp));
 382
 383         /* fake emulate a 16550 uart to make userspace code happy */
 384         tmp.type                = PORT_16550A;
 385         tmp.line                = priv->serial->minor;
 386         tmp.port                = 0;
 387         tmp.irq                 = 0;
 388         tmp.flags               = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
 389         tmp.xmit_fifo_size      = 1024;
 390         tmp.baud_base           = 9600;
 391         tmp.close_delay         = 5*HZ;
 392         tmp.closing_wait        = 30*HZ;
 393
 394         if (copy_to_user(serial, &tmp, sizeof(*serial)))
 395                 return -EFAULT;
 396         return 0;
 397 }
 398
 399 static int opticon_ioctl(struct tty_struct *tty, struct file *file,
 400                          unsigned int cmd, unsigned long arg)
 401 {
 402         struct usb_serial_port *port = tty->driver_data;
 403         struct opticon_private *priv = usb_get_serial_data(port->serial);
 404
 405         dbg("%s - port %d, cmd = 0x%x", __func__, port->number, cmd);
 406
 407         switch (cmd) {
 408         case TIOCGSERIAL:
 409                 return get_serial_info(priv,
 410                                        (struct serial_struct __user *)arg);
 411         }
 412
 413         return -ENOIOCTLCMD;
 414 }
 415
 416 static int opticon_startup(struct usb_serial *serial)
 417 {
 418         struct opticon_private *priv;
 419         struct usb_host_interface *intf;
 420         int i;
 421         int retval = -ENOMEM;
 422         bool bulk_in_found = false;
 423
 424         /* create our private serial structure */
 425         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 426         if (priv == NULL) {
 427                 dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__);
 428                 return -ENOMEM;
 429         }
 430         spin_lock_init(&priv->lock);
 431         priv->serial = serial;
 432         priv->port = serial->port[0];
 433         priv->udev = serial->dev;
 434
 435         /* find our bulk endpoint */
 436         intf = serial->interface->altsetting;
 437         for (i = 0; i < intf->desc.bNumEndpoints; ++i) {
 438                 struct usb_endpoint_descriptor *endpoint;
 439
 440                 endpoint = &intf->endpoint[i].desc;
 441                 if (!usb_endpoint_is_bulk_in(endpoint))
 442                         continue;
 443
 444                 priv->bulk_read_urb = usb_alloc_urb(0, GFP_KERNEL);
 445                 if (!priv->bulk_read_urb) {
 446                         dev_err(&priv->udev->dev, "out of memory\n");
 447                         goto error;
 448                 }
 449
 450                 priv->buffer_size = le16_to_cpu(endpoint->wMaxPacketSize) * 2;
 451                 priv->bulk_in_buffer = kmalloc(priv->buffer_size, GFP_KERNEL);
 452                 if (!priv->bulk_in_buffer) {
 453                         dev_err(&priv->udev->dev, "out of memory\n");
 454                         goto error;
 455                 }
 456
 457                 priv->bulk_address = endpoint->bEndpointAddress;
 458
 459                 /* set up our bulk urb */
 460                 usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
 461                                   usb_rcvbulkpipe(priv->udev,
 462                                                   endpoint->bEndpointAddress),
 463                                   priv->bulk_in_buffer, priv->buffer_size,
 464                                   opticon_bulk_callback, priv);
 465
 466                 bulk_in_found = true;
 467                 break;
 468                 }
 469
 470         if (!bulk_in_found) {
 471                 dev_err(&priv->udev->dev,
 472                         "Error - the proper endpoints were not found!\n");
 473                 goto error;
 474         }
 475
 476         usb_set_serial_data(serial, priv);
 477         return 0;
 478
 479 error:
 480         usb_free_urb(priv->bulk_read_urb);
 481         kfree(priv->bulk_in_buffer);
 482         kfree(priv);
 483         return retval;
 484 }
 485
 486 static void opticon_disconnect(struct usb_serial *serial)
 487 {
 488         struct opticon_private *priv = usb_get_serial_data(serial);
 489
 490         dbg("%s", __func__);
 491
 492         usb_kill_urb(priv->bulk_read_urb);
 493         usb_free_urb(priv->bulk_read_urb);
 494 }
 495
 496 static void opticon_release(struct usb_serial *serial)
 497 {
 498         struct opticon_private *priv = usb_get_serial_data(serial);
 499
 500         dbg("%s", __func__);
 501
 502         kfree(priv->bulk_in_buffer);
 503         kfree(priv);
 504 }
 505
 506 static int opticon_suspend(struct usb_interface *intf, pm_message_t message)
 507 {
 508         struct usb_serial *serial = usb_get_intfdata(intf);
 509         struct opticon_private *priv = usb_get_serial_data(serial);
 510
 511         usb_kill_urb(priv->bulk_read_urb);
 512         return 0;
 513 }
 514
 515 static int opticon_resume(struct usb_interface *intf)
 516 {
 517         struct usb_serial *serial = usb_get_intfdata(intf);
 518         struct opticon_private *priv = usb_get_serial_data(serial);
 519         struct usb_serial_port *port = serial->port[0];
 520         int result;
 521
 522         mutex_lock(&port->port.mutex);
 523         /* This is protected by the port mutex against close/open */
 524         if (test_bit(ASYNCB_INITIALIZED, &port->port.flags))
 525                 result = usb_submit_urb(priv->bulk_read_urb, GFP_NOIO);
 526         else
 527                 result = 0;
 528         mutex_unlock(&port->port.mutex);
 529         return result;
 530 }
 531
 532 static struct usb_driver opticon_driver = {
 533         .name =         "opticon",
 534         .probe =        usb_serial_probe,
 535         .disconnect =   usb_serial_disconnect,
 536         .suspend =      opticon_suspend,
 537         .resume =       opticon_resume,
 538         .id_table =     id_table,
 539         .no_dynamic_id =        1,
 540 };
 541
 542 static struct usb_serial_driver opticon_device = {
 543         .driver = {
 544                 .owner =        THIS_MODULE,
 545                 .name =         "opticon",
 546         },
 547         .id_table =             id_table,
 548         .usb_driver =           &opticon_driver,
 549         .num_ports =            1,
 550         .attach =               opticon_startup,
 551         .open =                 opticon_open,
 552         .close =                opticon_close,
 553         .write =                opticon_write,
 554         .write_room =           opticon_write_room,
 555         .disconnect =           opticon_disconnect,
 556         .release =              opticon_release,
 557         .throttle =             opticon_throttle,
 558         .unthrottle =           opticon_unthrottle,
 559         .ioctl =                opticon_ioctl,
 560         .tiocmget =             opticon_tiocmget,
 561 };
 562
 563 static int __init opticon_init(void)
 564 {
 565         int retval;
 566
 567         retval = usb_serial_register(&opticon_device);
 568         if (retval)
 569                 return retval;
 570         retval = usb_register(&opticon_driver);
 571         if (retval)
 572                 usb_serial_deregister(&opticon_device);
 573         return retval;
 574 }
 575
 576 static void __exit opticon_exit(void)
 577 {
 578         usb_deregister(&opticon_driver);
 579         usb_serial_deregister(&opticon_device);
 580 }
 581
 582 module_init(opticon_init);
 583 module_exit(opticon_exit);
 584 MODULE_LICENSE("GPL");
 585
 586 module_param(debug, bool, S_IRUGO | S_IWUSR);
 587 MODULE_PARM_DESC(debug, "Debug enabled or not");