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                 err("%s - No tty available", __FUNCTION__);
 276                 return ;
 277         }
 278
 279         count = min(64, serial_buf_data_avail(priv->rx_buf));
 280
 281         if (count <= 0)
 282                 return; //We have finished sending everything.
 283
 284         tty_prepare_flip_string(tty, &data, count);
 285         if (!data){
 286                 err("%s- kzalloc(%d) failed.", __FUNCTION__, count);
 287                 return;
 288         }
 289
 290         serial_buf_get(priv->rx_buf, data, count);
 291
 292         tty_flip_buffer_push(tty);
 293
 294         if (serial_buf_data_avail(priv->rx_buf))
 295                 schedule_work(&priv->rx_work);
 296
 297         return;
 298 }
 299 /* End of private methods */
 300
 301 static int aircable_probe(struct usb_serial *serial,
 302                           const struct usb_device_id *id)
 303 {
 304         struct usb_host_interface *iface_desc = serial->interface->cur_altsetting;
 305         struct usb_endpoint_descriptor *endpoint;
 306         int num_bulk_out=0;
 307         int i;
 308
 309         for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
 310                 endpoint = &iface_desc->endpoint[i].desc;
 311                 if (usb_endpoint_is_bulk_out(endpoint)) {
 312                         dbg("found bulk out on endpoint %d", i);
 313                         ++num_bulk_out;
 314                 }
 315         }
 316
 317         if (num_bulk_out == 0) {
 318                 dbg("Invalid interface, discarding");
 319                 return -ENODEV;
 320         }
 321
 322         return 0;
 323 }
 324
 325 static int aircable_attach (struct usb_serial *serial)
 326 {
 327         struct usb_serial_port *port = serial->port[0];
 328         struct aircable_private *priv;
 329
 330         priv = kzalloc(sizeof(struct aircable_private), GFP_KERNEL);
 331         if (!priv){
 332                 err("%s- kmalloc(%Zd) failed.", __FUNCTION__,
 333                         sizeof(struct aircable_private));
 334                 return -ENOMEM;
 335         }
 336
 337         /* Allocation of Circular Buffers */
 338         priv->tx_buf = serial_buf_alloc();
 339         if (priv->tx_buf == NULL) {
 340                 kfree(priv);
 341                 return -ENOMEM;
 342         }
 343
 344         priv->rx_buf = serial_buf_alloc();
 345         if (priv->rx_buf == NULL) {
 346                 kfree(priv->tx_buf);
 347                 kfree(priv);
 348                 return -ENOMEM;
 349         }
 350
 351         priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
 352         INIT_WORK(&priv->rx_work, aircable_read, port);
 353
 354         usb_set_serial_port_data(serial->port[0], priv);
 355
 356         return 0;
 357 }
 358
 359 static void aircable_shutdown(struct usb_serial *serial)
 360 {
 361
 362         struct usb_serial_port *port = serial->port[0];
 363         struct aircable_private *priv = usb_get_serial_port_data(port);
 364
 365         dbg("%s", __FUNCTION__);
 366
 367         if (priv) {
 368                 serial_buf_free(priv->tx_buf);
 369                 serial_buf_free(priv->rx_buf);
 370                 usb_set_serial_port_data(port, NULL);
 371                 kfree(priv);
 372         }
 373 }
 374
 375 static int aircable_write_room(struct usb_serial_port *port)
 376 {
 377         struct aircable_private *priv = usb_get_serial_port_data(port);
 378         return serial_buf_data_avail(priv->tx_buf);
 379 }
 380
 381 static int aircable_write(struct usb_serial_port *port,
 382                           const unsigned char *source, int count)
 383 {
 384         struct aircable_private *priv = usb_get_serial_port_data(port);
 385         int temp;
 386
 387         dbg("%s - port %d, %d bytes", __FUNCTION__, port->number, count);
 388
 389         usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, source);
 390
 391         if (!count){
 392                 dbg("%s - write request of 0 bytes", __FUNCTION__);
 393                 return count;
 394         }
 395
 396         temp = serial_buf_put(priv->tx_buf, source, count);
 397
 398         aircable_send(port);
 399
 400         if (count > AIRCABLE_BUF_SIZE)
 401                 count = AIRCABLE_BUF_SIZE;
 402
 403         return count;
 404
 405 }
 406
 407 static void aircable_write_bulk_callback(struct urb *urb)
 408 {
 409         struct usb_serial_port *port = urb->context;
 410         int result;
 411
 412         dbg("%s - urb->status: %d", __FUNCTION__ , urb->status);
 413
 414         /* This has been taken from cypress_m8.c cypress_write_int_callback */
 415         switch (urb->status) {
 416                 case 0:
 417                         /* success */
 418                         break;
 419                 case -ECONNRESET:
 420                 case -ENOENT:
 421                 case -ESHUTDOWN:
 422                         /* this urb is terminated, clean up */
 423                         dbg("%s - urb shutting down with status: %d",
 424                             __FUNCTION__, urb->status);
 425                         port->write_urb_busy = 0;
 426                         return;
 427                 default:
 428                         /* error in the urb, so we have to resubmit it */
 429                         dbg("%s - Overflow in write", __FUNCTION__);
 430                         dbg("%s - nonzero write bulk status received: %d",
 431                             __FUNCTION__, urb->status);
 432                         port->write_urb->transfer_buffer_length = 1;
 433                         port->write_urb->dev = port->serial->dev;
 434                         result = usb_submit_urb(port->write_urb, GFP_KERNEL);
 435                         if (result)
 436                                 dev_err(&urb->dev->dev,
 437                                         "%s - failed resubmitting write urb, error %d\n",
 438                                         __FUNCTION__, result);
 439                         else
 440                                 return;
 441         }
 442
 443         port->write_urb_busy = 0;
 444
 445         aircable_send(port);
 446 }
 447
 448 static void aircable_read_bulk_callback(struct urb *urb)
 449 {
 450         struct usb_serial_port *port = urb->context;
 451         struct aircable_private *priv = usb_get_serial_port_data(port);
 452         struct tty_struct *tty;
 453         unsigned long no_packages, remaining, package_length, i;
 454         int result, shift = 0;
 455         unsigned char *temp;
 456
 457         dbg("%s - port %d", __FUNCTION__, port->number);
 458
 459         if (urb->status) {
 460                 dbg("%s - urb->status = %d", __FUNCTION__, urb->status);
 461                 if (!port->open_count) {
 462                         dbg("%s - port is closed, exiting.", __FUNCTION__);
 463                         return;
 464                 }
 465                 if (urb->status == -EPROTO) {
 466                         dbg("%s - caught -EPROTO, resubmitting the urb",
 467                             __FUNCTION__);
 468                         usb_fill_bulk_urb(port->read_urb, port->serial->dev,
 469                                           usb_rcvbulkpipe(port->serial->dev,
 470                                                           port->bulk_in_endpointAddress),
 471                                           port->read_urb->transfer_buffer,
 472                                           port->read_urb->transfer_buffer_length,
 473                                           aircable_read_bulk_callback, port);
 474
 475                         result = usb_submit_urb(urb, GFP_ATOMIC);
 476                         if (result)
 477                                 dev_err(&urb->dev->dev,
 478                                         "%s - failed resubmitting read urb, error %d\n",
 479                                         __FUNCTION__, result);
 480                         return;
 481                 }
 482                 dbg("%s - unable to handle the error, exiting.", __FUNCTION__);
 483                 return;
 484         }
 485
 486         usb_serial_debug_data(debug, &port->dev, __FUNCTION__,
 487                                 urb->actual_length,urb->transfer_buffer);
 488
 489         tty = port->tty;
 490         if (tty && urb->actual_length) {
 491                 if (urb->actual_length <= 2) {
 492                         /* This is an incomplete package */
 493                         serial_buf_put(priv->rx_buf, urb->transfer_buffer,
 494                                        urb->actual_length);
 495                 } else {
 496                         temp = urb->transfer_buffer;
 497                         if (temp[0] == RX_HEADER_0)
 498                                 shift = HCI_HEADER_LENGTH;
 499
 500                         remaining = urb->actual_length;
 501                         no_packages = urb->actual_length / (HCI_COMPLETE_FRAME);
 502
 503                         if (urb->actual_length % HCI_COMPLETE_FRAME != 0)
 504                                 no_packages+=1;
 505
 506                         for (i = 0; i < no_packages ;i++) {
 507                                 if (remaining > (HCI_COMPLETE_FRAME))
 508                                         package_length = HCI_COMPLETE_FRAME;
 509                                 else
 510                                         package_length = remaining;
 511                                 remaining -= package_length;
 512
 513                                 serial_buf_put(priv->rx_buf,
 514                                         urb->transfer_buffer + shift +
 515                                         (HCI_COMPLETE_FRAME) * (i),
 516                                         package_length - shift);
 517                         }
 518                 }
 519                 aircable_read(port);
 520         }
 521
 522         /* Schedule the next read _if_ we are still open */
 523         if (port->open_count) {
 524                 usb_fill_bulk_urb(port->read_urb, port->serial->dev,
 525                                   usb_rcvbulkpipe(port->serial->dev,
 526                                                   port->bulk_in_endpointAddress),
 527                                   port->read_urb->transfer_buffer,
 528                                   port->read_urb->transfer_buffer_length,
 529                                   aircable_read_bulk_callback, port);
 530
 531                 result = usb_submit_urb(urb, GFP_ATOMIC);
 532                 if (result)
 533                         dev_err(&urb->dev->dev,
 534                                 "%s - failed resubmitting read urb, error %d\n",
 535                                 __FUNCTION__, result);
 536         }
 537
 538         return;
 539 }
 540
 541 /* Based on ftdi_sio.c throttle */
 542 static void aircable_throttle(struct usb_serial_port *port)
 543 {
 544         struct aircable_private *priv = usb_get_serial_port_data(port);
 545         unsigned long flags;
 546
 547         dbg("%s - port %d", __FUNCTION__, port->number);
 548
 549         spin_lock_irqsave(&priv->rx_lock, flags);
 550         priv->rx_flags |= THROTTLED;
 551         spin_unlock_irqrestore(&priv->rx_lock, flags);
 552 }
 553
 554 /* Based on ftdi_sio.c unthrottle */
 555 static void aircable_unthrottle(struct usb_serial_port *port)
 556 {
 557         struct aircable_private *priv = usb_get_serial_port_data(port);
 558         int actually_throttled;
 559         unsigned long flags;
 560
 561         dbg("%s - port %d", __FUNCTION__, port->number);
 562
 563         spin_lock_irqsave(&priv->rx_lock, flags);
 564         actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
 565         priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
 566         spin_unlock_irqrestore(&priv->rx_lock, flags);
 567
 568         if (actually_throttled)
 569                 schedule_work(&priv->rx_work);
 570 }
 571
 572 static struct usb_serial_driver aircable_device = {
 573         .description =          "aircable",
 574         .id_table =             id_table,
 575         .num_ports =            1,
 576         .attach =               aircable_attach,
 577         .probe =                aircable_probe,
 578         .shutdown =             aircable_shutdown,
 579         .write =                aircable_write,
 580         .write_room =           aircable_write_room,
 581         .write_bulk_callback =  aircable_write_bulk_callback,
 582         .read_bulk_callback =   aircable_read_bulk_callback,
 583         .throttle =             aircable_throttle,
 584         .unthrottle =           aircable_unthrottle,
 585 };
 586
 587 static struct usb_driver aircable_driver = {
 588         .name =         "aircable",
 589         .probe =        usb_serial_probe,
 590         .disconnect =   usb_serial_disconnect,
 591         .id_table =     id_table,
 592 };
 593
 594 static int __init aircable_init (void)
 595 {
 596         int retval;
 597         retval = usb_serial_register(&aircable_device);
 598         if (retval)
 599                 goto failed_serial_register;
 600         retval = usb_register(&aircable_driver);
 601         if (retval)
 602                 goto failed_usb_register;
 603         return 0;
 604
 605 failed_serial_register:
 606         usb_serial_deregister(&aircable_device);
 607 failed_usb_register:
 608         return retval;
 609 }
 610
 611 static void __exit aircable_exit (void)
 612 {
 613         usb_deregister(&aircable_driver);
 614         usb_serial_deregister(&aircable_device);
 615 }
 616
 617 MODULE_AUTHOR(DRIVER_AUTHOR);
 618 MODULE_DESCRIPTION(DRIVER_DESC);
 619 MODULE_VERSION(DRIVER_VERSION);
 620 MODULE_LICENSE("GPL");
 621
 622 module_init(aircable_init);
 623 module_exit(aircable_exit);
 624
 625 module_param(debug, bool, S_IRUGO | S_IWUSR);
 626 MODULE_PARM_DESC(debug, "Debug enabled or not");