git.oblomov.eu Git - linux-2.6/blob - drivers/usb/serial/aircable.c

   1 /*
   2  * AIRcable USB Bluetooth Dongle Driver.
   3  *
   4  * Copyright (C) 2006 Manuel Francisco Naranjo (naranjo.manuel@gmail.com)
   5  * This program is free software; you can redistribute it and/or modify it under
   6  * the terms of the GNU General Public License version 2 as published by the
   7  * Free Software Foundation.
   8  *
   9  * The device works as an standard CDC device, it has 2 interfaces, the first
  10  * one is for firmware access and the second is the serial one.
  11  * The protocol is very simply, there are two posibilities reading or writing.
  12  * When writting the first urb must have a Header that starts with 0x20 0x29 the
  13  * next two bytes must say how much data will be sended.
  14  * When reading the process is almost equal except that the header starts with
  15  * 0x00 0x20.
  16  *
  17  * The device simply need some stuff to understand data comming from the usb
  18  * buffer: The First and Second byte is used for a Header, the Third and Fourth
  19  * tells the  device the amount of information the package holds.
  20  * Packages are 60 bytes long Header Stuff.
  21  * When writting to the device the first two bytes of the header are 0x20 0x29
  22  * When reading the bytes are 0x00 0x20, or 0x00 0x10, there is an strange
  23  * situation, when too much data arrives to the device because it sends the data
  24  * but with out the header. I will use a simply hack to override this situation,
  25  * if there is data coming that does not contain any header, then that is data
  26  * that must go directly to the tty, as there is no documentation about if there
  27  * is any other control code, I will simply check for the first
  28  * one.
  29  *
  30  * The driver registers himself with the USB-serial core and the USB Core. I had
  31  * to implement a probe function agains USB-serial, because other way, the
  32  * driver was attaching himself to both interfaces. I have tryed with different
  33  * configurations of usb_serial_driver with out exit, only the probe function
  34  * could handle this correctly.
  35  *
  36  * I have taken some info from a Greg Kroah-Hartman article:
  37  * http://www.linuxjournal.com/article/6573
  38  * And from Linux Device Driver Kit CD, which is a great work, the authors taken
  39  * the work to recompile lots of information an knowladge in drivers development
  40  * and made it all avaible inside a cd.
  41  * URL: http://kernel.org/pub/linux/kernel/people/gregkh/ddk/
  42  *
  43  */
  44
  45 #include <linux/tty.h>
  46 #include <linux/tty_flip.h>
  47 #include <linux/circ_buf.h>
  48 #include <linux/usb.h>
  49 #include <linux/usb/serial.h>
  50
  51 static int debug;
  52
  53 /* Vendor and Product ID */
  54 #define AIRCABLE_VID            0x16CA
  55 #define AIRCABLE_USB_PID        0x1502
  56
  57 /* write buffer size defines */
  58 #define AIRCABLE_BUF_SIZE       2048
  59
  60 /* Protocol Stuff */
  61 #define HCI_HEADER_LENGTH       0x4
  62 #define TX_HEADER_0             0x20
  63 #define TX_HEADER_1             0x29
  64 #define RX_HEADER_0             0x00
  65 #define RX_HEADER_1             0x20
  66 #define MAX_HCI_FRAMESIZE       60
  67 #define HCI_COMPLETE_FRAME      64
  68
  69 /* rx_flags */
  70 #define THROTTLED               0x01
  71 #define ACTUALLY_THROTTLED      0x02
  72
  73 /*
  74  * Version Information
  75  */
  76 #define DRIVER_VERSION "v1.0b2"
  77 #define DRIVER_AUTHOR "Naranjo, Manuel Francisco <naranjo.manuel@gmail.com>"
  78 #define DRIVER_DESC "AIRcable USB Driver"
  79
  80 /* ID table that will be registered with USB core */
  81 static struct usb_device_id id_table [] = {
  82         { USB_DEVICE(AIRCABLE_VID, AIRCABLE_USB_PID) },
  83         { },
  84 };
  85 MODULE_DEVICE_TABLE(usb, id_table);
  86
  87
  88 /* Internal Structure */
  89 struct aircable_private {
  90         spinlock_t rx_lock;             /* spinlock for the receive lines */
  91         struct circ_buf *tx_buf;        /* write buffer */
  92         struct circ_buf *rx_buf;        /* read buffer */
  93         int rx_flags;                   /* for throttilng */
  94         struct work_struct rx_work;     /* work cue for the receiving line */
  95 };
  96
  97 /* Private methods */
  98
  99 /* Circular Buffer Methods, code from ti_usb_3410_5052 used */
 100 /*
 101  * serial_buf_clear
 102  *
 103  * Clear out all data in the circular buffer.
 104  */
 105 static void serial_buf_clear(struct circ_buf *cb)
 106 {
 107         cb->head = cb->tail = 0;
 108 }
 109
 110 /*
 111  * serial_buf_alloc
 112  *
 113  * Allocate a circular buffer and all associated memory.
 114  */
 115 static struct circ_buf *serial_buf_alloc(void)
 116 {
 117         struct circ_buf *cb;
 118         cb = kmalloc(sizeof(struct circ_buf), GFP_KERNEL);
 119         if (cb == NULL)
 120                 return NULL;
 121         cb->buf = kmalloc(AIRCABLE_BUF_SIZE, GFP_KERNEL);
 122         if (cb->buf == NULL) {
 123                 kfree(cb);
 124                 return NULL;
 125         }
 126         serial_buf_clear(cb);
 127         return cb;
 128 }
 129
 130 /*
 131  * serial_buf_free
 132  *
 133  * Free the buffer and all associated memory.
 134  */
 135 static void serial_buf_free(struct circ_buf *cb)
 136 {
 137         kfree(cb->buf);
 138         kfree(cb);
 139 }
 140
 141 /*
 142  * serial_buf_data_avail
 143  *
 144  * Return the number of bytes of data available in the circular
 145  * buffer.
 146  */
 147 static int serial_buf_data_avail(struct circ_buf *cb)
 148 {
 149         return CIRC_CNT(cb->head,cb->tail,AIRCABLE_BUF_SIZE);
 150 }
 151
 152 /*
 153  * serial_buf_put
 154  *
 155  * Copy data data from a user buffer and put it into the circular buffer.
 156  * Restrict to the amount of space available.
 157  *
 158  * Return the number of bytes copied.
 159  */
 160 static int serial_buf_put(struct circ_buf *cb, const char *buf, int count)
 161 {
 162         int c, ret = 0;
 163         while (1) {
 164                 c = CIRC_SPACE_TO_END(cb->head, cb->tail, AIRCABLE_BUF_SIZE);
 165                 if (count < c)
 166                         c = count;
 167                 if (c <= 0)
 168                         break;
 169                 memcpy(cb->buf + cb->head, buf, c);
 170                 cb->head = (cb->head + c) & (AIRCABLE_BUF_SIZE-1);
 171                 buf += c;
 172                 count -= c;
 173                 ret= c;
 174         }
 175         return ret;
 176 }
 177
 178 /*
 179  * serial_buf_get
 180  *
 181  * Get data from the circular buffer and copy to the given buffer.
 182  * Restrict to the amount of data available.
 183  *
 184  * Return the number of bytes copied.
 185  */
 186 static int serial_buf_get(struct circ_buf *cb, char *buf, int count)
 187 {
 188         int c, ret = 0;
 189         while (1) {
 190                 c = CIRC_CNT_TO_END(cb->head, cb->tail, AIRCABLE_BUF_SIZE);
 191                 if (count < c)
 192                         c = count;
 193                 if (c <= 0)
 194                         break;
 195                 memcpy(buf, cb->buf + cb->tail, c);
 196                 cb->tail = (cb->tail + c) & (AIRCABLE_BUF_SIZE-1);
 197                 buf += c;
 198                 count -= c;
 199                 ret= c;
 200         }
 201         return ret;
 202 }
 203
 204 /* End of circula buffer methods */
 205
 206 static void aircable_send(struct usb_serial_port *port)
 207 {
 208         int count, result;
 209         struct aircable_private *priv = usb_get_serial_port_data(port);
 210         unsigned char* buf;
 211         dbg("%s - port %d", __FUNCTION__, port->number);
 212         if (port->write_urb_busy)
 213                 return;
 214
 215         count = min(serial_buf_data_avail(priv->tx_buf), MAX_HCI_FRAMESIZE);
 216         if (count == 0)
 217                 return;
 218
 219         buf = kzalloc(count + HCI_HEADER_LENGTH, GFP_ATOMIC);
 220         if (!buf) {
 221                 err("%s- kzalloc(%d) failed.", __FUNCTION__,
 222                     count + HCI_HEADER_LENGTH);
 223                 return;
 224         }
 225
 226         buf[0] = TX_HEADER_0;
 227         buf[1] = TX_HEADER_1;
 228         buf[2] = (unsigned char)count;
 229         buf[3] = (unsigned char)(count >> 8);
 230         serial_buf_get(priv->tx_buf,buf + HCI_HEADER_LENGTH, MAX_HCI_FRAMESIZE);
 231
 232         memcpy(port->write_urb->transfer_buffer, buf,
 233                count + HCI_HEADER_LENGTH);
 234
 235         kfree(buf);
 236         port->write_urb_busy = 1;
 237         usb_serial_debug_data(debug, &port->dev, __FUNCTION__,
 238                               count + HCI_HEADER_LENGTH,
 239                               port->write_urb->transfer_buffer);
 240         port->write_urb->transfer_buffer_length = count + HCI_HEADER_LENGTH;
 241         port->write_urb->dev = port->serial->dev;
 242         result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
 243
 244         if (result) {
 245                 dev_err(&port->dev,
 246                         "%s - failed submitting write urb, error %d\n",
 247                         __FUNCTION__, result);
 248                 port->write_urb_busy = 0;
 249         }
 250
 251         schedule_work(&port->work);
 252 }
 253
 254 static void aircable_read(void *params)
 255 {
 256         struct usb_serial_port *port = params;
 257         struct aircable_private *priv = usb_get_serial_port_data(port);
 258         struct tty_struct *tty;
 259         unsigned char *data;
 260         int count;
 261         if (priv->rx_flags & THROTTLED){
 262                 if (priv->rx_flags & ACTUALLY_THROTTLED)
 263                         schedule_work(&priv->rx_work);
 264                 return;
 265         }
 266
 267         /* By now I will flush data to the tty in packages of no more than
 268          * 64 bytes, to ensure I do not get throttled.
 269          * Ask USB mailing list for better aproach.
 270          */
 271         tty = port->tty;
 272
 273         if (!tty)
 274                 schedule_work(&priv->rx_work);
 275
 276         count = min(64, serial_buf_data_avail(priv->rx_buf));
 277
 278         if (count <= 0)
 279                 return; //We have finished sending everything.
 280
 281         tty_prepare_flip_string(tty, &data, count);
 282         if (!data){
 283                 err("%s- kzalloc(%d) failed.", __FUNCTION__, count);
 284                 return;
 285         }
 286
 287         serial_buf_get(priv->rx_buf, data, count);
 288
 289         tty_flip_buffer_push(tty);
 290
 291         if (serial_buf_data_avail(priv->rx_buf))
 292                 schedule_work(&priv->rx_work);
 293
 294         return;
 295 }
 296 /* End of private methods */
 297
 298 static int aircable_probe(struct usb_serial *serial,
 299                           const struct usb_device_id *id)
 300 {
 301         struct usb_host_interface *iface_desc = serial->interface->cur_altsetting;
 302         struct usb_endpoint_descriptor *endpoint;
 303         int num_bulk_out=0;
 304         int i;
 305
 306         for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
 307                 endpoint = &iface_desc->endpoint[i].desc;
 308                 if (((endpoint->bEndpointAddress & 0x80) == 0x00) &&
 309                         ((endpoint->bmAttributes & 3) == 0x02)) {
 310                         /* we found our bulk out endpoint */
 311                         dbg("found bulk out on endpoint %d", i);
 312                         ++num_bulk_out;
 313                 }
 314         }
 315
 316         if (num_bulk_out == 0) {
 317                 dbg("Invalid interface, discarding");
 318                 return -ENODEV;
 319         }
 320
 321         return 0;
 322 }
 323
 324 static int aircable_attach (struct usb_serial *serial)
 325 {
 326         struct usb_serial_port *port = serial->port[0];
 327         struct aircable_private *priv;
 328
 329         priv = kzalloc(sizeof(struct aircable_private), GFP_KERNEL);
 330         if (!priv){
 331                 err("%s- kmalloc(%Zd) failed.", __FUNCTION__,
 332                         sizeof(struct aircable_private));
 333                 return -ENOMEM;
 334         }
 335
 336         /* Allocation of Circular Buffers */
 337         priv->tx_buf = serial_buf_alloc();
 338         if (priv->tx_buf == NULL) {
 339                 kfree(priv);
 340                 return -ENOMEM;
 341         }
 342
 343         priv->rx_buf = serial_buf_alloc();
 344         if (priv->rx_buf == NULL) {
 345                 kfree(priv->tx_buf);
 346                 kfree(priv);
 347                 return -ENOMEM;
 348         }
 349
 350         priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
 351         INIT_WORK(&priv->rx_work, aircable_read, port);
 352
 353         usb_set_serial_port_data(serial->port[0], priv);
 354
 355         return 0;
 356 }
 357
 358 static void aircable_shutdown(struct usb_serial *serial)
 359 {
 360
 361         struct usb_serial_port *port = serial->port[0];
 362         struct aircable_private *priv = usb_get_serial_port_data(port);
 363
 364         dbg("%s", __FUNCTION__);
 365
 366         if (priv) {
 367                 serial_buf_free(priv->tx_buf);
 368                 serial_buf_free(priv->rx_buf);
 369                 usb_set_serial_port_data(port, NULL);
 370                 kfree(priv);
 371         }
 372 }
 373
 374 static int aircable_write_room(struct usb_serial_port *port)
 375 {
 376         struct aircable_private *priv = usb_get_serial_port_data(port);
 377         return serial_buf_data_avail(priv->tx_buf);
 378 }
 379
 380 static int aircable_write(struct usb_serial_port *port,
 381                           const unsigned char *source, int count)
 382 {
 383         struct aircable_private *priv = usb_get_serial_port_data(port);
 384         int temp;
 385
 386         dbg("%s - port %d, %d bytes", __FUNCTION__, port->number, count);
 387
 388         usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, source);
 389
 390         if (!count){
 391                 dbg("%s - write request of 0 bytes", __FUNCTION__);
 392                 return count;
 393         }
 394
 395         temp = serial_buf_put(priv->tx_buf, source, count);
 396
 397         aircable_send(port);
 398
 399         if (count > AIRCABLE_BUF_SIZE)
 400                 count = AIRCABLE_BUF_SIZE;
 401
 402         return count;
 403
 404 }
 405
 406 static void aircable_write_bulk_callback(struct urb *urb, struct pt_regs *regs)
 407 {
 408         struct usb_serial_port *port = urb->context;
 409         int result;
 410
 411         dbg("%s - urb->status: %d", __FUNCTION__ , urb->status);
 412
 413         /* This has been taken from cypress_m8.c cypress_write_int_callback */
 414         switch (urb->status) {
 415                 case 0:
 416                         /* success */
 417                         break;
 418                 case -ECONNRESET:
 419                 case -ENOENT:
 420                 case -ESHUTDOWN:
 421                         /* this urb is terminated, clean up */
 422                         dbg("%s - urb shutting down with status: %d",
 423                             __FUNCTION__, urb->status);
 424                         port->write_urb_busy = 0;
 425                         return;
 426                 default:
 427                         /* error in the urb, so we have to resubmit it */
 428                         dbg("%s - Overflow in write", __FUNCTION__);
 429                         dbg("%s - nonzero write bulk status received: %d",
 430                             __FUNCTION__, urb->status);
 431                         port->write_urb->transfer_buffer_length = 1;
 432                         port->write_urb->dev = port->serial->dev;
 433                         result = usb_submit_urb(port->write_urb, GFP_KERNEL);
 434                         if (result)
 435                                 dev_err(&urb->dev->dev,
 436                                         "%s - failed resubmitting write urb, error %d\n",
 437                                         __FUNCTION__, result);
 438                         else
 439                                 return;
 440         }
 441
 442         port->write_urb_busy = 0;
 443
 444         aircable_send(port);
 445 }
 446
 447 static void aircable_read_bulk_callback(struct urb *urb, struct pt_regs *regs)
 448 {
 449         struct usb_serial_port *port = urb->context;
 450         struct aircable_private *priv = usb_get_serial_port_data(port);
 451         struct tty_struct *tty;
 452         unsigned long no_packages, remaining, package_length, i;
 453         int result, shift = 0;
 454         unsigned char *temp;
 455
 456         dbg("%s - port %d", __FUNCTION__, port->number);
 457
 458         if (urb->status) {
 459                 dbg("%s - urb->status = %d", __FUNCTION__, urb->status);
 460                 if (!port->open_count) {
 461                         dbg("%s - port is closed, exiting.", __FUNCTION__);
 462                         return;
 463                 }
 464                 if (urb->status == -EPROTO) {
 465                         dbg("%s - caught -EPROTO, resubmitting the urb",
 466                             __FUNCTION__);
 467                         usb_fill_bulk_urb(port->read_urb, port->serial->dev,
 468                                           usb_rcvbulkpipe(port->serial->dev,
 469                                                           port->bulk_in_endpointAddress),
 470                                           port->read_urb->transfer_buffer,
 471                                           port->read_urb->transfer_buffer_length,
 472                                           aircable_read_bulk_callback, port);
 473
 474                         result = usb_submit_urb(urb, GFP_ATOMIC);
 475                         if (result)
 476                                 dev_err(&urb->dev->dev,
 477                                         "%s - failed resubmitting read urb, error %d\n",
 478                                         __FUNCTION__, result);
 479                         return;
 480                 }
 481                 dbg("%s - unable to handle the error, exiting.", __FUNCTION__);
 482                 return;
 483         }
 484
 485         usb_serial_debug_data(debug, &port->dev, __FUNCTION__,
 486                                 urb->actual_length,urb->transfer_buffer);
 487
 488         tty = port->tty;
 489         if (tty && urb->actual_length) {
 490                 if (urb->actual_length <= 2) {
 491                         /* This is an incomplete package */
 492                         serial_buf_put(priv->rx_buf, urb->transfer_buffer,
 493                                        urb->actual_length);
 494                 } else {
 495                         temp = urb->transfer_buffer;
 496                         if (temp[0] == RX_HEADER_0)
 497                                 shift = HCI_HEADER_LENGTH;
 498
 499                         remaining = urb->actual_length;
 500                         no_packages = urb->actual_length / (HCI_COMPLETE_FRAME);
 501
 502                         if (urb->actual_length % HCI_COMPLETE_FRAME != 0)
 503                                 no_packages+=1;
 504
 505                         for (i = 0; i < no_packages ;i++) {
 506                                 if (remaining > (HCI_COMPLETE_FRAME))
 507                                         package_length = HCI_COMPLETE_FRAME;
 508                                 else
 509                                         package_length = remaining;
 510                                 remaining -= package_length;
 511
 512                                 serial_buf_put(priv->rx_buf,
 513                                         urb->transfer_buffer + shift +
 514                                         (HCI_COMPLETE_FRAME) * (i),
 515                                         package_length - shift);
 516                         }
 517                 }
 518                 aircable_read(port);
 519         }
 520
 521         /* Schedule the next read _if_ we are still open */
 522         if (port->open_count) {
 523                 usb_fill_bulk_urb(port->read_urb, port->serial->dev,
 524                                   usb_rcvbulkpipe(port->serial->dev,
 525                                                   port->bulk_in_endpointAddress),
 526                                   port->read_urb->transfer_buffer,
 527                                   port->read_urb->transfer_buffer_length,
 528                                   aircable_read_bulk_callback, port);
 529
 530                 result = usb_submit_urb(urb, GFP_ATOMIC);
 531                 if (result)
 532                         dev_err(&urb->dev->dev,
 533                                 "%s - failed resubmitting read urb, error %d\n",
 534                                 __FUNCTION__, result);
 535         }
 536
 537         return;
 538 }
 539
 540 /* Based on ftdi_sio.c throttle */
 541 static void aircable_throttle(struct usb_serial_port *port)
 542 {
 543         struct aircable_private *priv = usb_get_serial_port_data(port);
 544         unsigned long flags;
 545
 546         dbg("%s - port %d", __FUNCTION__, port->number);
 547
 548         spin_lock_irqsave(&priv->rx_lock, flags);
 549         priv->rx_flags |= THROTTLED;
 550         spin_unlock_irqrestore(&priv->rx_lock, flags);
 551 }
 552
 553 /* Based on ftdi_sio.c unthrottle */
 554 static void aircable_unthrottle(struct usb_serial_port *port)
 555 {
 556         struct aircable_private *priv = usb_get_serial_port_data(port);
 557         int actually_throttled;
 558         unsigned long flags;
 559
 560         dbg("%s - port %d", __FUNCTION__, port->number);
 561
 562         spin_lock_irqsave(&priv->rx_lock, flags);
 563         actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
 564         priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
 565         spin_unlock_irqrestore(&priv->rx_lock, flags);
 566
 567         if (actually_throttled)
 568                 schedule_work(&priv->rx_work);
 569 }
 570
 571 static struct usb_serial_driver aircable_device = {
 572         .description =          "aircable",
 573         .id_table =             id_table,
 574         .num_ports =            1,
 575         .attach =               aircable_attach,
 576         .probe =                aircable_probe,
 577         .shutdown =             aircable_shutdown,
 578         .write =                aircable_write,
 579         .write_room =           aircable_write_room,
 580         .write_bulk_callback =  aircable_write_bulk_callback,
 581         .read_bulk_callback =   aircable_read_bulk_callback,
 582         .throttle =             aircable_throttle,
 583         .unthrottle =           aircable_unthrottle,
 584 };
 585
 586 static struct usb_driver aircable_driver = {
 587         .name =         "aircable",
 588         .probe =        usb_serial_probe,
 589         .disconnect =   usb_serial_disconnect,
 590         .id_table =     id_table,
 591 };
 592
 593 static int __init aircable_init (void)
 594 {
 595         int retval;
 596         retval = usb_serial_register(&aircable_device);
 597         if (retval)
 598                 goto failed_serial_register;
 599         retval = usb_register(&aircable_driver);
 600         if (retval)
 601                 goto failed_usb_register;
 602         return 0;
 603
 604 failed_serial_register:
 605         usb_serial_deregister(&aircable_device);
 606 failed_usb_register:
 607         return retval;
 608 }
 609
 610 static void __exit aircable_exit (void)
 611 {
 612         usb_deregister(&aircable_driver);
 613         usb_serial_deregister(&aircable_device);
 614 }
 615
 616 MODULE_AUTHOR(DRIVER_AUTHOR);
 617 MODULE_DESCRIPTION(DRIVER_DESC);
 618 MODULE_VERSION(DRIVER_VERSION);
 619 MODULE_LICENSE("GPL");
 620
 621 module_init(aircable_init);
 622 module_exit(aircable_exit);
 623
 624 module_param(debug, bool, S_IRUGO | S_IWUSR);
 625 MODULE_PARM_DESC(debug, "Debug enabled or not");