git.oblomov.eu Git - linux-2.6/blob - drivers/usb/serial/oti6858.c

   1 /*
   2  * Ours Technology Inc. OTi-6858 USB to serial adapter driver.
   3  *
   4  * Copyleft  (C) 2007 Kees Lemmens (adapted for kernel 2.6.20)
   5  * Copyright (C) 2006 Tomasz Michal Lukaszewski (FIXME: add e-mail)
   6  * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com)
   7  * Copyright (C) 2003 IBM Corp.
   8  *
   9  * Many thanks to the authors of pl2303 driver: all functions in this file
  10  * are heavily based on pl2303 code, buffering code is a 1-to-1 copy.
  11  *
  12  * Warning! You use this driver on your own risk! The only official
  13  * description of this device I have is datasheet from manufacturer,
  14  * and it doesn't contain almost any information needed to write a driver.
  15  * Almost all knowlegde used while writing this driver was gathered by:
  16  *  - analyzing traffic between device and the M$ Windows 2000 driver,
  17  *  - trying different bit combinations and checking pin states
  18  *    with a voltmeter,
  19  *  - receiving malformed frames and producing buffer overflows
  20  *    to learn how errors are reported,
  21  * So, THIS CODE CAN DESTROY OTi-6858 AND ANY OTHER DEVICES, THAT ARE
  22  * CONNECTED TO IT!
  23  *
  24  * This program is free software; you can redistribute it and/or modify
  25  * it under the terms of the GNU General Public License as published by
  26  * the Free Software Foundation; either version 2 of the License.
  27  *
  28  * See Documentation/usb/usb-serial.txt for more information on using this
  29  * driver
  30  *
  31  * TODO:
  32  *  - implement correct flushing for ioctls and oti6858_close()
  33  *  - check how errors (rx overflow, parity error, framing error) are reported
  34  *  - implement oti6858_break_ctl()
  35  *  - implement more ioctls
  36  *  - test/implement flow control
  37  *  - allow setting custom baud rates
  38  */
  39
  40 #include <linux/kernel.h>
  41 #include <linux/errno.h>
  42 #include <linux/init.h>
  43 #include <linux/slab.h>
  44 #include <linux/tty.h>
  45 #include <linux/tty_driver.h>
  46 #include <linux/tty_flip.h>
  47 #include <linux/serial.h>
  48 #include <linux/module.h>
  49 #include <linux/moduleparam.h>
  50 #include <linux/spinlock.h>
  51 #include <linux/usb.h>
  52 #include <linux/usb/serial.h>
  53 #include <linux/uaccess.h>
  54 #include "oti6858.h"
  55
  56 #define OTI6858_DESCRIPTION \
  57         "Ours Technology Inc. OTi-6858 USB to serial adapter driver"
  58 #define OTI6858_AUTHOR "Tomasz Michal Lukaszewski <FIXME@FIXME>"
  59 #define OTI6858_VERSION "0.1"
  60
  61 static struct usb_device_id id_table [] = {
  62         { USB_DEVICE(OTI6858_VENDOR_ID, OTI6858_PRODUCT_ID) },
  63         { }
  64 };
  65
  66 MODULE_DEVICE_TABLE(usb, id_table);
  67
  68 static struct usb_driver oti6858_driver = {
  69         .name =         "oti6858",
  70         .probe =        usb_serial_probe,
  71         .disconnect =   usb_serial_disconnect,
  72         .id_table =     id_table,
  73         .no_dynamic_id =        1,
  74 };
  75
  76 static int debug;
  77
  78
  79 /* buffering code, copied from pl2303 driver */
  80 #define PL2303_BUF_SIZE         1024
  81 #define PL2303_TMP_BUF_SIZE     1024
  82
  83 struct oti6858_buf {
  84         unsigned int    buf_size;
  85         char            *buf_buf;
  86         char            *buf_get;
  87         char            *buf_put;
  88 };
  89
  90 /* requests */
  91 #define OTI6858_REQ_GET_STATUS          (USB_DIR_IN | USB_TYPE_VENDOR | 0x00)
  92 #define OTI6858_REQ_T_GET_STATUS        0x01
  93
  94 #define OTI6858_REQ_SET_LINE            (USB_DIR_OUT | USB_TYPE_VENDOR | 0x00)
  95 #define OTI6858_REQ_T_SET_LINE          0x00
  96
  97 #define OTI6858_REQ_CHECK_TXBUFF        (USB_DIR_IN | USB_TYPE_VENDOR | 0x01)
  98 #define OTI6858_REQ_T_CHECK_TXBUFF      0x00
  99
 100 /* format of the control packet */
 101 struct oti6858_control_pkt {
 102         __le16  divisor;        /* baud rate = 96000000 / (16 * divisor), LE */
 103 #define OTI6858_MAX_BAUD_RATE   3000000
 104         u8      frame_fmt;
 105 #define FMT_STOP_BITS_MASK      0xc0
 106 #define FMT_STOP_BITS_1         0x00
 107 #define FMT_STOP_BITS_2         0x40    /* 1.5 stop bits if FMT_DATA_BITS_5 */
 108 #define FMT_PARITY_MASK         0x38
 109 #define FMT_PARITY_NONE         0x00
 110 #define FMT_PARITY_ODD          0x08
 111 #define FMT_PARITY_EVEN         0x18
 112 #define FMT_PARITY_MARK         0x28
 113 #define FMT_PARITY_SPACE        0x38
 114 #define FMT_DATA_BITS_MASK      0x03
 115 #define FMT_DATA_BITS_5         0x00
 116 #define FMT_DATA_BITS_6         0x01
 117 #define FMT_DATA_BITS_7         0x02
 118 #define FMT_DATA_BITS_8         0x03
 119         u8      something;      /* always equals 0x43 */
 120         u8      control;        /* settings of flow control lines */
 121 #define CONTROL_MASK            0x0c
 122 #define CONTROL_DTR_HIGH        0x08
 123 #define CONTROL_RTS_HIGH        0x04
 124         u8      tx_status;
 125 #define TX_BUFFER_EMPTIED       0x09
 126         u8      pin_state;
 127 #define PIN_MASK                0x3f
 128 #define PIN_RTS                 0x20    /* output pin */
 129 #define PIN_CTS                 0x10    /* input pin, active low */
 130 #define PIN_DSR                 0x08    /* input pin, active low */
 131 #define PIN_DTR                 0x04    /* output pin */
 132 #define PIN_RI                  0x02    /* input pin, active low */
 133 #define PIN_DCD                 0x01    /* input pin, active low */
 134         u8      rx_bytes_avail;         /* number of bytes in rx buffer */;
 135 };
 136
 137 #define OTI6858_CTRL_PKT_SIZE   sizeof(struct oti6858_control_pkt)
 138 #define OTI6858_CTRL_EQUALS_PENDING(a, priv) \
 139         (((a)->divisor == (priv)->pending_setup.divisor) \
 140           && ((a)->control == (priv)->pending_setup.control) \
 141           && ((a)->frame_fmt == (priv)->pending_setup.frame_fmt))
 142
 143 /* function prototypes */
 144 static int oti6858_open(struct tty_struct *tty,
 145                         struct usb_serial_port *port, struct file *filp);
 146 static void oti6858_close(struct tty_struct *tty,
 147                         struct usb_serial_port *port, struct file *filp);
 148 static void oti6858_set_termios(struct tty_struct *tty,
 149                         struct usb_serial_port *port, struct ktermios *old);
 150 static int oti6858_ioctl(struct tty_struct *tty, struct file *file,
 151                         unsigned int cmd, unsigned long arg);
 152 static void oti6858_read_int_callback(struct urb *urb);
 153 static void oti6858_read_bulk_callback(struct urb *urb);
 154 static void oti6858_write_bulk_callback(struct urb *urb);
 155 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
 156                         const unsigned char *buf, int count);
 157 static int oti6858_write_room(struct tty_struct *tty);
 158 static int oti6858_chars_in_buffer(struct tty_struct *tty);
 159 static int oti6858_tiocmget(struct tty_struct *tty, struct file *file);
 160 static int oti6858_tiocmset(struct tty_struct *tty, struct file *file,
 161                                 unsigned int set, unsigned int clear);
 162 static int oti6858_startup(struct usb_serial *serial);
 163 static void oti6858_shutdown(struct usb_serial *serial);
 164
 165 /* functions operating on buffers */
 166 static struct oti6858_buf *oti6858_buf_alloc(unsigned int size);
 167 static void oti6858_buf_free(struct oti6858_buf *pb);
 168 static void oti6858_buf_clear(struct oti6858_buf *pb);
 169 static unsigned int oti6858_buf_data_avail(struct oti6858_buf *pb);
 170 static unsigned int oti6858_buf_space_avail(struct oti6858_buf *pb);
 171 static unsigned int oti6858_buf_put(struct oti6858_buf *pb, const char *buf,
 172                                         unsigned int count);
 173 static unsigned int oti6858_buf_get(struct oti6858_buf *pb, char *buf,
 174                                         unsigned int count);
 175
 176
 177 /* device info */
 178 static struct usb_serial_driver oti6858_device = {
 179         .driver = {
 180                 .owner =        THIS_MODULE,
 181                 .name =         "oti6858",
 182         },
 183         .id_table =             id_table,
 184         .num_ports =            1,
 185         .open =                 oti6858_open,
 186         .close =                oti6858_close,
 187         .write =                oti6858_write,
 188         .ioctl =                oti6858_ioctl,
 189         .set_termios =          oti6858_set_termios,
 190         .tiocmget =             oti6858_tiocmget,
 191         .tiocmset =             oti6858_tiocmset,
 192         .read_bulk_callback =   oti6858_read_bulk_callback,
 193         .read_int_callback =    oti6858_read_int_callback,
 194         .write_bulk_callback =  oti6858_write_bulk_callback,
 195         .write_room =           oti6858_write_room,
 196         .chars_in_buffer =      oti6858_chars_in_buffer,
 197         .attach =               oti6858_startup,
 198         .shutdown =             oti6858_shutdown,
 199 };
 200
 201 struct oti6858_private {
 202         spinlock_t lock;
 203
 204         struct oti6858_buf *buf;
 205         struct oti6858_control_pkt status;
 206
 207         struct {
 208                 u8 read_urb_in_use;
 209                 u8 write_urb_in_use;
 210                 u8 termios_initialized;
 211         } flags;
 212         struct delayed_work delayed_write_work;
 213
 214         struct {
 215                 __le16 divisor;
 216                 u8 frame_fmt;
 217                 u8 control;
 218         } pending_setup;
 219         u8 transient;
 220         u8 setup_done;
 221         struct delayed_work delayed_setup_work;
 222
 223         wait_queue_head_t intr_wait;
 224         struct usb_serial_port *port;   /* USB port with which associated */
 225 };
 226
 227 #undef dbg
 228 /* #define dbg(format, arg...) printk(KERN_INFO "%s: " format "\n", __FILE__, ## arg) */
 229 #define dbg(format, arg...) printk(KERN_INFO "" format "\n", ## arg)
 230
 231 static void setup_line(struct work_struct *work)
 232 {
 233         struct oti6858_private *priv = container_of(work,
 234                         struct oti6858_private, delayed_setup_work.work);
 235         struct usb_serial_port *port = priv->port;
 236         struct oti6858_control_pkt *new_setup;
 237         unsigned long flags;
 238         int result;
 239
 240         dbg("%s(port = %d)", __func__, port->number);
 241
 242         new_setup = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
 243         if (new_setup == NULL) {
 244                 dev_err(&port->dev, "%s(): out of memory!\n", __func__);
 245                 /* we will try again */
 246                 schedule_delayed_work(&priv->delayed_setup_work,
 247                                                 msecs_to_jiffies(2));
 248                 return;
 249         }
 250
 251         result = usb_control_msg(port->serial->dev,
 252                                 usb_rcvctrlpipe(port->serial->dev, 0),
 253                                 OTI6858_REQ_T_GET_STATUS,
 254                                 OTI6858_REQ_GET_STATUS,
 255                                 0, 0,
 256                                 new_setup, OTI6858_CTRL_PKT_SIZE,
 257                                 100);
 258
 259         if (result != OTI6858_CTRL_PKT_SIZE) {
 260                 dev_err(&port->dev, "%s(): error reading status\n", __func__);
 261                 kfree(new_setup);
 262                 /* we will try again */
 263                 schedule_delayed_work(&priv->delayed_setup_work,
 264                                                         msecs_to_jiffies(2));
 265                 return;
 266         }
 267
 268         spin_lock_irqsave(&priv->lock, flags);
 269         if (!OTI6858_CTRL_EQUALS_PENDING(new_setup, priv)) {
 270                 new_setup->divisor = priv->pending_setup.divisor;
 271                 new_setup->control = priv->pending_setup.control;
 272                 new_setup->frame_fmt = priv->pending_setup.frame_fmt;
 273
 274                 spin_unlock_irqrestore(&priv->lock, flags);
 275                 result = usb_control_msg(port->serial->dev,
 276                                         usb_sndctrlpipe(port->serial->dev, 0),
 277                                         OTI6858_REQ_T_SET_LINE,
 278                                         OTI6858_REQ_SET_LINE,
 279                                         0, 0,
 280                                         new_setup, OTI6858_CTRL_PKT_SIZE,
 281                                         100);
 282         } else {
 283                 spin_unlock_irqrestore(&priv->lock, flags);
 284                 result = 0;
 285         }
 286         kfree(new_setup);
 287
 288         spin_lock_irqsave(&priv->lock, flags);
 289         if (result != OTI6858_CTRL_PKT_SIZE)
 290                 priv->transient = 0;
 291         priv->setup_done = 1;
 292         spin_unlock_irqrestore(&priv->lock, flags);
 293
 294         dbg("%s(): submitting interrupt urb", __func__);
 295         port->interrupt_in_urb->dev = port->serial->dev;
 296         result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
 297         if (result != 0) {
 298                 dev_err(&port->dev, "%s(): usb_submit_urb() failed"
 299                                 " with error %d\n", __func__, result);
 300         }
 301 }
 302
 303 void send_data(struct work_struct *work)
 304 {
 305         struct oti6858_private *priv = container_of(work,
 306                         struct oti6858_private, delayed_write_work.work);
 307         struct usb_serial_port *port = priv->port;
 308         int count = 0, result;
 309         unsigned long flags;
 310         unsigned char allow;
 311
 312         dbg("%s(port = %d)", __func__, port->number);
 313
 314         spin_lock_irqsave(&priv->lock, flags);
 315         if (priv->flags.write_urb_in_use) {
 316                 spin_unlock_irqrestore(&priv->lock, flags);
 317                 schedule_delayed_work(&priv->delayed_write_work,
 318                                                 msecs_to_jiffies(2));
 319                 return;
 320         }
 321         priv->flags.write_urb_in_use = 1;
 322
 323         count = oti6858_buf_data_avail(priv->buf);
 324         spin_unlock_irqrestore(&priv->lock, flags);
 325         if (count > port->bulk_out_size)
 326                 count = port->bulk_out_size;
 327
 328         if (count != 0) {
 329                 result = usb_control_msg(port->serial->dev,
 330                                 usb_rcvctrlpipe(port->serial->dev, 0),
 331                                 OTI6858_REQ_T_CHECK_TXBUFF,
 332                                 OTI6858_REQ_CHECK_TXBUFF,
 333                                 count, 0, &allow, 1, 100);
 334                 if (result != 1 || allow != 0)
 335                         count = 0;
 336         }
 337
 338         if (count == 0) {
 339                 priv->flags.write_urb_in_use = 0;
 340
 341                 dbg("%s(): submitting interrupt urb", __func__);
 342                 port->interrupt_in_urb->dev = port->serial->dev;
 343                 result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
 344                 if (result != 0) {
 345                         dev_err(&port->dev, "%s(): usb_submit_urb() failed"
 346                                 " with error %d\n", __func__, result);
 347                 }
 348                 return;
 349         }
 350
 351         spin_lock_irqsave(&priv->lock, flags);
 352         oti6858_buf_get(priv->buf, port->write_urb->transfer_buffer, count);
 353         spin_unlock_irqrestore(&priv->lock, flags);
 354
 355         port->write_urb->transfer_buffer_length = count;
 356         port->write_urb->dev = port->serial->dev;
 357         result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
 358         if (result != 0) {
 359                 dev_err(&port->dev, "%s(): usb_submit_urb() failed"
 360                                " with error %d\n", __func__, result);
 361                 priv->flags.write_urb_in_use = 0;
 362         }
 363
 364         usb_serial_port_softint(port);
 365 }
 366
 367 static int oti6858_startup(struct usb_serial *serial)
 368 {
 369         struct usb_serial_port *port = serial->port[0];
 370         struct oti6858_private *priv;
 371         int i;
 372
 373         for (i = 0; i < serial->num_ports; ++i) {
 374                 priv = kzalloc(sizeof(struct oti6858_private), GFP_KERNEL);
 375                 if (!priv)
 376                         break;
 377                 priv->buf = oti6858_buf_alloc(PL2303_BUF_SIZE);
 378                 if (priv->buf == NULL) {
 379                         kfree(priv);
 380                         break;
 381                 }
 382
 383                 spin_lock_init(&priv->lock);
 384                 init_waitqueue_head(&priv->intr_wait);
 385 /*              INIT_WORK(&priv->setup_work, setup_line, serial->port[i]); */
 386 /*              INIT_WORK(&priv->write_work, send_data, serial->port[i]); */
 387                 priv->port = port;
 388                 INIT_DELAYED_WORK(&priv->delayed_setup_work, setup_line);
 389                 INIT_DELAYED_WORK(&priv->delayed_write_work, send_data);
 390
 391                 usb_set_serial_port_data(serial->port[i], priv);
 392         }
 393         if (i == serial->num_ports)
 394                 return 0;
 395
 396         for (--i; i >= 0; --i) {
 397                 priv = usb_get_serial_port_data(serial->port[i]);
 398                 oti6858_buf_free(priv->buf);
 399                 kfree(priv);
 400                 usb_set_serial_port_data(serial->port[i], NULL);
 401         }
 402         return -ENOMEM;
 403 }
 404
 405 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
 406                         const unsigned char *buf, int count)
 407 {
 408         struct oti6858_private *priv = usb_get_serial_port_data(port);
 409         unsigned long flags;
 410
 411         dbg("%s(port = %d, count = %d)", __func__, port->number, count);
 412
 413         if (!count)
 414                 return count;
 415
 416         spin_lock_irqsave(&priv->lock, flags);
 417         count = oti6858_buf_put(priv->buf, buf, count);
 418         spin_unlock_irqrestore(&priv->lock, flags);
 419
 420         return count;
 421 }
 422
 423 static int oti6858_write_room(struct tty_struct *tty)
 424 {
 425         struct usb_serial_port *port = tty->driver_data;
 426         struct oti6858_private *priv = usb_get_serial_port_data(port);
 427         int room = 0;
 428         unsigned long flags;
 429
 430         dbg("%s(port = %d)", __func__, port->number);
 431
 432         spin_lock_irqsave(&priv->lock, flags);
 433         room = oti6858_buf_space_avail(priv->buf);
 434         spin_unlock_irqrestore(&priv->lock, flags);
 435
 436         return room;
 437 }
 438
 439 static int oti6858_chars_in_buffer(struct tty_struct *tty)
 440 {
 441         struct usb_serial_port *port = tty->driver_data;
 442         struct oti6858_private *priv = usb_get_serial_port_data(port);
 443         int chars = 0;
 444         unsigned long flags;
 445
 446         dbg("%s(port = %d)", __func__, port->number);
 447
 448         spin_lock_irqsave(&priv->lock, flags);
 449         chars = oti6858_buf_data_avail(priv->buf);
 450         spin_unlock_irqrestore(&priv->lock, flags);
 451
 452         return chars;
 453 }
 454
 455 static void oti6858_set_termios(struct tty_struct *tty,
 456                 struct usb_serial_port *port, struct ktermios *old_termios)
 457 {
 458         struct oti6858_private *priv = usb_get_serial_port_data(port);
 459         unsigned long flags;
 460         unsigned int cflag;
 461         u8 frame_fmt, control;
 462         __le16 divisor;
 463         int br;
 464
 465         dbg("%s(port = %d)", __func__, port->number);
 466
 467         if (!tty) {
 468                 dbg("%s(): no tty structures", __func__);
 469                 return;
 470         }
 471
 472         spin_lock_irqsave(&priv->lock, flags);
 473         if (!priv->flags.termios_initialized) {
 474                 *(tty->termios) = tty_std_termios;
 475                 tty->termios->c_cflag = B38400 | CS8 | CREAD | HUPCL | CLOCAL;
 476                 tty->termios->c_ispeed = 38400;
 477                 tty->termios->c_ospeed = 38400;
 478                 priv->flags.termios_initialized = 1;
 479         }
 480         spin_unlock_irqrestore(&priv->lock, flags);
 481
 482         cflag = tty->termios->c_cflag;
 483
 484         spin_lock_irqsave(&priv->lock, flags);
 485         divisor = priv->pending_setup.divisor;
 486         frame_fmt = priv->pending_setup.frame_fmt;
 487         control = priv->pending_setup.control;
 488         spin_unlock_irqrestore(&priv->lock, flags);
 489
 490         frame_fmt &= ~FMT_DATA_BITS_MASK;
 491         switch (cflag & CSIZE) {
 492         case CS5:
 493                 frame_fmt |= FMT_DATA_BITS_5;
 494                 break;
 495         case CS6:
 496                 frame_fmt |= FMT_DATA_BITS_6;
 497                 break;
 498         case CS7:
 499                 frame_fmt |= FMT_DATA_BITS_7;
 500                 break;
 501         default:
 502         case CS8:
 503                 frame_fmt |= FMT_DATA_BITS_8;
 504                 break;
 505         }
 506
 507         /* manufacturer claims that this device can work with baud rates
 508          * up to 3 Mbps; I've tested it only on 115200 bps, so I can't
 509          * guarantee that any other baud rate will work (especially
 510          * the higher ones)
 511          */
 512         br = tty_get_baud_rate(tty);
 513         if (br == 0) {
 514                 divisor = 0;
 515         } else {
 516                 int real_br;
 517                 int new_divisor;
 518                 br = min(br, OTI6858_MAX_BAUD_RATE);
 519
 520                 new_divisor = (96000000 + 8 * br) / (16 * br);
 521                 real_br = 96000000 / (16 * new_divisor);
 522                 divisor = cpu_to_le16(new_divisor);
 523                 tty_encode_baud_rate(tty, real_br, real_br);
 524         }
 525
 526         frame_fmt &= ~FMT_STOP_BITS_MASK;
 527         if ((cflag & CSTOPB) != 0)
 528                 frame_fmt |= FMT_STOP_BITS_2;
 529         else
 530                 frame_fmt |= FMT_STOP_BITS_1;
 531
 532         frame_fmt &= ~FMT_PARITY_MASK;
 533         if ((cflag & PARENB) != 0) {
 534                 if ((cflag & PARODD) != 0)
 535                         frame_fmt |= FMT_PARITY_ODD;
 536                 else
 537                         frame_fmt |= FMT_PARITY_EVEN;
 538         } else {
 539                 frame_fmt |= FMT_PARITY_NONE;
 540         }
 541
 542         control &= ~CONTROL_MASK;
 543         if ((cflag & CRTSCTS) != 0)
 544                 control |= (CONTROL_DTR_HIGH | CONTROL_RTS_HIGH);
 545
 546         /* change control lines if we are switching to or from B0 */
 547         /* FIXME:
 548         spin_lock_irqsave(&priv->lock, flags);
 549         control = priv->line_control;
 550         if ((cflag & CBAUD) == B0)
 551                 priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
 552         else
 553                 priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
 554         if (control != priv->line_control) {
 555                 control = priv->line_control;
 556                 spin_unlock_irqrestore(&priv->lock, flags);
 557                 set_control_lines(serial->dev, control);
 558         } else {
 559                 spin_unlock_irqrestore(&priv->lock, flags);
 560         }
 561         */
 562
 563         spin_lock_irqsave(&priv->lock, flags);
 564         if (divisor != priv->pending_setup.divisor
 565                         || control != priv->pending_setup.control
 566                         || frame_fmt != priv->pending_setup.frame_fmt) {
 567                 priv->pending_setup.divisor = divisor;
 568                 priv->pending_setup.control = control;
 569                 priv->pending_setup.frame_fmt = frame_fmt;
 570         }
 571         spin_unlock_irqrestore(&priv->lock, flags);
 572 }
 573
 574 static int oti6858_open(struct tty_struct *tty,
 575                         struct usb_serial_port *port, struct file *filp)
 576 {
 577         struct oti6858_private *priv = usb_get_serial_port_data(port);
 578         struct ktermios tmp_termios;
 579         struct usb_serial *serial = port->serial;
 580         struct oti6858_control_pkt *buf;
 581         unsigned long flags;
 582         int result;
 583
 584         dbg("%s(port = %d)", __func__, port->number);
 585
 586         usb_clear_halt(serial->dev, port->write_urb->pipe);
 587         usb_clear_halt(serial->dev, port->read_urb->pipe);
 588
 589         if (port->port.count != 1)
 590                 return 0;
 591
 592         buf = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
 593         if (buf == NULL) {
 594                 dev_err(&port->dev, "%s(): out of memory!\n", __func__);
 595                 return -ENOMEM;
 596         }
 597
 598         result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
 599                                 OTI6858_REQ_T_GET_STATUS,
 600                                 OTI6858_REQ_GET_STATUS,
 601                                 0, 0,
 602                                 buf, OTI6858_CTRL_PKT_SIZE,
 603                                 100);
 604         if (result != OTI6858_CTRL_PKT_SIZE) {
 605                 /* assume default (after power-on reset) values */
 606                 buf->divisor = cpu_to_le16(0x009c);     /* 38400 bps */
 607                 buf->frame_fmt = 0x03;  /* 8N1 */
 608                 buf->something = 0x43;
 609                 buf->control = 0x4c;    /* DTR, RTS */
 610                 buf->tx_status = 0x00;
 611                 buf->pin_state = 0x5b;  /* RTS, CTS, DSR, DTR, RI, DCD */
 612                 buf->rx_bytes_avail = 0x00;
 613         }
 614
 615         spin_lock_irqsave(&priv->lock, flags);
 616         memcpy(&priv->status, buf, OTI6858_CTRL_PKT_SIZE);
 617         priv->pending_setup.divisor = buf->divisor;
 618         priv->pending_setup.frame_fmt = buf->frame_fmt;
 619         priv->pending_setup.control = buf->control;
 620         spin_unlock_irqrestore(&priv->lock, flags);
 621         kfree(buf);
 622
 623         dbg("%s(): submitting interrupt urb", __func__);
 624         port->interrupt_in_urb->dev = serial->dev;
 625         result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 626         if (result != 0) {
 627                 dev_err(&port->dev, "%s(): usb_submit_urb() failed"
 628                                " with error %d\n", __func__, result);
 629                 oti6858_close(tty, port, NULL);
 630                 return -EPROTO;
 631         }
 632
 633         /* setup termios */
 634         if (tty)
 635                 oti6858_set_termios(tty, port, &tmp_termios);
 636
 637         return 0;
 638 }
 639
 640 static void oti6858_close(struct tty_struct *tty,
 641                         struct usb_serial_port *port, struct file *filp)
 642 {
 643         struct oti6858_private *priv = usb_get_serial_port_data(port);
 644         unsigned long flags;
 645         long timeout;
 646         wait_queue_t wait;
 647
 648         dbg("%s(port = %d)", __func__, port->number);
 649
 650         /* wait for data to drain from the buffer */
 651         spin_lock_irqsave(&priv->lock, flags);
 652         timeout = 30 * HZ;      /* PL2303_CLOSING_WAIT */
 653         init_waitqueue_entry(&wait, current);
 654         add_wait_queue(&tty->write_wait, &wait);
 655         dbg("%s(): entering wait loop", __func__);
 656         for (;;) {
 657                 set_current_state(TASK_INTERRUPTIBLE);
 658                 if (oti6858_buf_data_avail(priv->buf) == 0
 659                 || timeout == 0 || signal_pending(current)
 660                 || port->serial->disconnected)
 661                         break;
 662                 spin_unlock_irqrestore(&priv->lock, flags);
 663                 timeout = schedule_timeout(timeout);
 664                 spin_lock_irqsave(&priv->lock, flags);
 665         }
 666         set_current_state(TASK_RUNNING);
 667         remove_wait_queue(&tty->write_wait, &wait);
 668         dbg("%s(): after wait loop", __func__);
 669
 670         /* clear out any remaining data in the buffer */
 671         oti6858_buf_clear(priv->buf);
 672         spin_unlock_irqrestore(&priv->lock, flags);
 673
 674         /* wait for characters to drain from the device */
 675         /* (this is long enough for the entire 256 byte */
 676         /* pl2303 hardware buffer to drain with no flow */
 677         /* control for data rates of 1200 bps or more, */
 678         /* for lower rates we should really know how much */
 679         /* data is in the buffer to compute a delay */
 680         /* that is not unnecessarily long) */
 681         /* FIXME
 682         bps = tty_get_baud_rate(tty);
 683         if (bps > 1200)
 684                 timeout = max((HZ*2560)/bps,HZ/10);
 685         else
 686         */
 687                 timeout = 2*HZ;
 688         schedule_timeout_interruptible(timeout);
 689         dbg("%s(): after schedule_timeout_interruptible()", __func__);
 690
 691         /* cancel scheduled setup */
 692         cancel_delayed_work(&priv->delayed_setup_work);
 693         cancel_delayed_work(&priv->delayed_write_work);
 694         flush_scheduled_work();
 695
 696         /* shutdown our urbs */
 697         dbg("%s(): shutting down urbs", __func__);
 698         usb_kill_urb(port->write_urb);
 699         usb_kill_urb(port->read_urb);
 700         usb_kill_urb(port->interrupt_in_urb);
 701
 702         /*
 703         if (tty && (tty->termios->c_cflag) & HUPCL) {
 704                 // drop DTR and RTS
 705                 spin_lock_irqsave(&priv->lock, flags);
 706                 priv->pending_setup.control &= ~CONTROL_MASK;
 707                 spin_unlock_irqrestore(&priv->lock, flags);
 708         }
 709         */
 710 }
 711
 712 static int oti6858_tiocmset(struct tty_struct *tty, struct file *file,
 713                                 unsigned int set, unsigned int clear)
 714 {
 715         struct usb_serial_port *port = tty->driver_data;
 716         struct oti6858_private *priv = usb_get_serial_port_data(port);
 717         unsigned long flags;
 718         u8 control;
 719
 720         dbg("%s(port = %d, set = 0x%08x, clear = 0x%08x)",
 721                                 __func__, port->number, set, clear);
 722
 723         if (!usb_get_intfdata(port->serial->interface))
 724                 return -ENODEV;
 725
 726         /* FIXME: check if this is correct (active high/low) */
 727         spin_lock_irqsave(&priv->lock, flags);
 728         control = priv->pending_setup.control;
 729         if ((set & TIOCM_RTS) != 0)
 730                 control |= CONTROL_RTS_HIGH;
 731         if ((set & TIOCM_DTR) != 0)
 732                 control |= CONTROL_DTR_HIGH;
 733         if ((clear & TIOCM_RTS) != 0)
 734                 control &= ~CONTROL_RTS_HIGH;
 735         if ((clear & TIOCM_DTR) != 0)
 736                 control &= ~CONTROL_DTR_HIGH;
 737
 738         if (control != priv->pending_setup.control)
 739                 priv->pending_setup.control = control;
 740
 741         spin_unlock_irqrestore(&priv->lock, flags);
 742         return 0;
 743 }
 744
 745 static int oti6858_tiocmget(struct tty_struct *tty, struct file *file)
 746 {
 747         struct usb_serial_port *port = tty->driver_data;
 748         struct oti6858_private *priv = usb_get_serial_port_data(port);
 749         unsigned long flags;
 750         unsigned pin_state;
 751         unsigned result = 0;
 752
 753         dbg("%s(port = %d)", __func__, port->number);
 754
 755         if (!usb_get_intfdata(port->serial->interface))
 756                 return -ENODEV;
 757
 758         spin_lock_irqsave(&priv->lock, flags);
 759         pin_state = priv->status.pin_state & PIN_MASK;
 760         spin_unlock_irqrestore(&priv->lock, flags);
 761
 762         /* FIXME: check if this is correct (active high/low) */
 763         if ((pin_state & PIN_RTS) != 0)
 764                 result |= TIOCM_RTS;
 765         if ((pin_state & PIN_CTS) != 0)
 766                 result |= TIOCM_CTS;
 767         if ((pin_state & PIN_DSR) != 0)
 768                 result |= TIOCM_DSR;
 769         if ((pin_state & PIN_DTR) != 0)
 770                 result |= TIOCM_DTR;
 771         if ((pin_state & PIN_RI) != 0)
 772                 result |= TIOCM_RI;
 773         if ((pin_state & PIN_DCD) != 0)
 774                 result |= TIOCM_CD;
 775
 776         dbg("%s() = 0x%08x", __func__, result);
 777
 778         return result;
 779 }
 780
 781 static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
 782 {
 783         struct oti6858_private *priv = usb_get_serial_port_data(port);
 784         unsigned long flags;
 785         unsigned int prev, status;
 786         unsigned int changed;
 787
 788         spin_lock_irqsave(&priv->lock, flags);
 789         prev = priv->status.pin_state;
 790         spin_unlock_irqrestore(&priv->lock, flags);
 791
 792         while (1) {
 793                 wait_event_interruptible(priv->intr_wait,
 794                                         priv->status.pin_state != prev);
 795                 if (signal_pending(current))
 796                         return -ERESTARTSYS;
 797
 798                 spin_lock_irqsave(&priv->lock, flags);
 799                 status = priv->status.pin_state & PIN_MASK;
 800                 spin_unlock_irqrestore(&priv->lock, flags);
 801
 802                 changed = prev ^ status;
 803                 /* FIXME: check if this is correct (active high/low) */
 804                 if (((arg & TIOCM_RNG) && (changed & PIN_RI)) ||
 805                     ((arg & TIOCM_DSR) && (changed & PIN_DSR)) ||
 806                     ((arg & TIOCM_CD)  && (changed & PIN_DCD)) ||
 807                     ((arg & TIOCM_CTS) && (changed & PIN_CTS)))
 808                         return 0;
 809                 prev = status;
 810         }
 811
 812         /* NOTREACHED */
 813         return 0;
 814 }
 815
 816 static int oti6858_ioctl(struct tty_struct *tty, struct file *file,
 817                         unsigned int cmd, unsigned long arg)
 818 {
 819         struct usb_serial_port *port = tty->driver_data;
 820
 821         dbg("%s(port = %d, cmd = 0x%04x, arg = 0x%08lx)",
 822                                 __func__, port->number, cmd, arg);
 823
 824         switch (cmd) {
 825         case TIOCMIWAIT:
 826                 dbg("%s(): TIOCMIWAIT", __func__);
 827                 return wait_modem_info(port, arg);
 828         default:
 829                 dbg("%s(): 0x%04x not supported", __func__, cmd);
 830                 break;
 831         }
 832         return -ENOIOCTLCMD;
 833 }
 834
 835
 836 static void oti6858_shutdown(struct usb_serial *serial)
 837 {
 838         struct oti6858_private *priv;
 839         int i;
 840
 841         dbg("%s()", __func__);
 842
 843         for (i = 0; i < serial->num_ports; ++i) {
 844                 priv = usb_get_serial_port_data(serial->port[i]);
 845                 if (priv) {
 846                         oti6858_buf_free(priv->buf);
 847                         kfree(priv);
 848                         usb_set_serial_port_data(serial->port[i], NULL);
 849                 }
 850         }
 851 }
 852
 853 static void oti6858_read_int_callback(struct urb *urb)
 854 {
 855         struct usb_serial_port *port =  urb->context;
 856         struct oti6858_private *priv = usb_get_serial_port_data(port);
 857         int transient = 0, can_recv = 0, resubmit = 1;
 858         int status = urb->status;
 859
 860         dbg("%s(port = %d, status = %d)",
 861                                 __func__, port->number, status);
 862
 863         switch (status) {
 864         case 0:
 865                 /* success */
 866                 break;
 867         case -ECONNRESET:
 868         case -ENOENT:
 869         case -ESHUTDOWN:
 870                 /* this urb is terminated, clean up */
 871                 dbg("%s(): urb shutting down with status: %d",
 872                                         __func__, status);
 873                 return;
 874         default:
 875                 dbg("%s(): nonzero urb status received: %d",
 876                                         __func__, status);
 877                 break;
 878         }
 879
 880         if (status == 0 && urb->actual_length == OTI6858_CTRL_PKT_SIZE) {
 881                 struct oti6858_control_pkt *xs = urb->transfer_buffer;
 882                 unsigned long flags;
 883
 884                 spin_lock_irqsave(&priv->lock, flags);
 885
 886                 if (!priv->transient) {
 887                         if (!OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
 888                                 if (xs->rx_bytes_avail == 0) {
 889                                         priv->transient = 4;
 890                                         priv->setup_done = 0;
 891                                         resubmit = 0;
 892                                         dbg("%s(): scheduling setup_line()",
 893                                             __func__);
 894                                         schedule_delayed_work(&priv->delayed_setup_work, 0);
 895                                 }
 896                         }
 897                 } else {
 898                         if (OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
 899                                 priv->transient = 0;
 900                         } else if (!priv->setup_done) {
 901                                 resubmit = 0;
 902                         } else if (--priv->transient == 0) {
 903                                 if (xs->rx_bytes_avail == 0) {
 904                                         priv->transient = 4;
 905                                         priv->setup_done = 0;
 906                                         resubmit = 0;
 907                                         dbg("%s(): scheduling setup_line()",
 908                                             __func__);
 909                                         schedule_delayed_work(&priv->delayed_setup_work, 0);
 910                                 }
 911                         }
 912                 }
 913
 914                 if (!priv->transient) {
 915                         if (xs->pin_state != priv->status.pin_state)
 916                                 wake_up_interruptible(&priv->intr_wait);
 917                         memcpy(&priv->status, xs, OTI6858_CTRL_PKT_SIZE);
 918                 }
 919
 920                 if (!priv->transient && xs->rx_bytes_avail != 0) {
 921                         can_recv = xs->rx_bytes_avail;
 922                         priv->flags.read_urb_in_use = 1;
 923                 }
 924
 925                 transient = priv->transient;
 926                 spin_unlock_irqrestore(&priv->lock, flags);
 927         }
 928
 929         if (can_recv) {
 930                 int result;
 931
 932                 port->read_urb->dev = port->serial->dev;
 933                 result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
 934                 if (result != 0) {
 935                         priv->flags.read_urb_in_use = 0;
 936                         dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
 937                                         " error %d\n", __func__, result);
 938                 } else {
 939                         resubmit = 0;
 940                 }
 941         } else if (!transient) {
 942                 unsigned long flags;
 943
 944                 spin_lock_irqsave(&priv->lock, flags);
 945                 if (priv->flags.write_urb_in_use == 0
 946                                 && oti6858_buf_data_avail(priv->buf) != 0) {
 947                         schedule_delayed_work(&priv->delayed_write_work, 0);
 948                         resubmit = 0;
 949                 }
 950                 spin_unlock_irqrestore(&priv->lock, flags);
 951         }
 952
 953         if (resubmit) {
 954                 int result;
 955
 956 /*              dbg("%s(): submitting interrupt urb", __func__); */
 957                 urb->dev = port->serial->dev;
 958                 result = usb_submit_urb(urb, GFP_ATOMIC);
 959                 if (result != 0) {
 960                         dev_err(&urb->dev->dev,
 961                                         "%s(): usb_submit_urb() failed with"
 962                                         " error %d\n", __func__, result);
 963                 }
 964         }
 965 }
 966
 967 static void oti6858_read_bulk_callback(struct urb *urb)
 968 {
 969         struct usb_serial_port *port =  urb->context;
 970         struct oti6858_private *priv = usb_get_serial_port_data(port);
 971         struct tty_struct *tty;
 972         unsigned char *data = urb->transfer_buffer;
 973         unsigned long flags;
 974         int status = urb->status;
 975         int result;
 976
 977         dbg("%s(port = %d, status = %d)",
 978                                 __func__, port->number, status);
 979
 980         spin_lock_irqsave(&priv->lock, flags);
 981         priv->flags.read_urb_in_use = 0;
 982         spin_unlock_irqrestore(&priv->lock, flags);
 983
 984         if (status != 0) {
 985                 if (!port->port.count) {
 986                         dbg("%s(): port is closed, exiting", __func__);
 987                         return;
 988                 }
 989                 /*
 990                 if (status == -EPROTO) {
 991                         * PL2303 mysteriously fails with -EPROTO reschedule
 992                            the read *
 993                         dbg("%s - caught -EPROTO, resubmitting the urb",
 994                                                                 __func__);
 995                         result = usb_submit_urb(urb, GFP_ATOMIC);
 996                         if (result)
 997                                 dev_err(&urb->dev->dev, "%s - failed resubmitting read urb, error %d\n", __func__, result);
 998                         return;
 999                 }
1000                 */
1001                 dbg("%s(): unable to handle the error, exiting", __func__);
1002                 return;
1003         }
1004
1005         tty = port->port.tty;
1006         if (tty != NULL && urb->actual_length > 0) {
1007                 tty_insert_flip_string(tty, data, urb->actual_length);
1008                 tty_flip_buffer_push(tty);
1009         }
1010
1011         /* schedule the interrupt urb if we are still open */
1012         if (port->port.count != 0) {
1013                 port->interrupt_in_urb->dev = port->serial->dev;
1014                 result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1015                 if (result != 0) {
1016                         dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
1017                                         " error %d\n", __func__, result);
1018                 }
1019         }
1020 }
1021
1022 static void oti6858_write_bulk_callback(struct urb *urb)
1023 {
1024         struct usb_serial_port *port =  urb->context;
1025         struct oti6858_private *priv = usb_get_serial_port_data(port);
1026         int status = urb->status;
1027         int result;
1028
1029         dbg("%s(port = %d, status = %d)",
1030                                 __func__, port->number, status);
1031
1032         switch (status) {
1033         case 0:
1034                 /* success */
1035                 break;
1036         case -ECONNRESET:
1037         case -ENOENT:
1038         case -ESHUTDOWN:
1039                 /* this urb is terminated, clean up */
1040                 dbg("%s(): urb shutting down with status: %d",
1041                                         __func__, status);
1042                 priv->flags.write_urb_in_use = 0;
1043                 return;
1044         default:
1045                 /* error in the urb, so we have to resubmit it */
1046                 dbg("%s(): nonzero write bulk status received: %d",
1047                                         __func__, status);
1048                 dbg("%s(): overflow in write", __func__);
1049
1050                 port->write_urb->transfer_buffer_length = 1;
1051                 port->write_urb->dev = port->serial->dev;
1052                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
1053                 if (result) {
1054                         dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
1055                                         " error %d\n", __func__, result);
1056                 } else {
1057                         return;
1058                 }
1059         }
1060
1061         priv->flags.write_urb_in_use = 0;
1062
1063         /* schedule the interrupt urb if we are still open */
1064         port->interrupt_in_urb->dev = port->serial->dev;
1065         dbg("%s(): submitting interrupt urb", __func__);
1066         result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1067         if (result != 0) {
1068                 dev_err(&port->dev, "%s(): failed submitting int urb,"
1069                                         " error %d\n", __func__, result);
1070         }
1071 }
1072
1073
1074 /*
1075  * oti6858_buf_alloc
1076  *
1077  * Allocate a circular buffer and all associated memory.
1078  */
1079 static struct oti6858_buf *oti6858_buf_alloc(unsigned int size)
1080 {
1081         struct oti6858_buf *pb;
1082
1083         if (size == 0)
1084                 return NULL;
1085
1086         pb = kmalloc(sizeof(struct oti6858_buf), GFP_KERNEL);
1087         if (pb == NULL)
1088                 return NULL;
1089
1090         pb->buf_buf = kmalloc(size, GFP_KERNEL);
1091         if (pb->buf_buf == NULL) {
1092                 kfree(pb);
1093                 return NULL;
1094         }
1095
1096         pb->buf_size = size;
1097         pb->buf_get = pb->buf_put = pb->buf_buf;
1098
1099         return pb;
1100 }
1101
1102 /*
1103  * oti6858_buf_free
1104  *
1105  * Free the buffer and all associated memory.
1106  */
1107 static void oti6858_buf_free(struct oti6858_buf *pb)
1108 {
1109         if (pb) {
1110                 kfree(pb->buf_buf);
1111                 kfree(pb);
1112         }
1113 }
1114
1115 /*
1116  * oti6858_buf_clear
1117  *
1118  * Clear out all data in the circular buffer.
1119  */
1120 static void oti6858_buf_clear(struct oti6858_buf *pb)
1121 {
1122         if (pb != NULL) {
1123                 /* equivalent to a get of all data available */
1124                 pb->buf_get = pb->buf_put;
1125         }
1126 }
1127
1128 /*
1129  * oti6858_buf_data_avail
1130  *
1131  * Return the number of bytes of data available in the circular
1132  * buffer.
1133  */
1134 static unsigned int oti6858_buf_data_avail(struct oti6858_buf *pb)
1135 {
1136         if (pb == NULL)
1137                 return 0;
1138         return (pb->buf_size + pb->buf_put - pb->buf_get) % pb->buf_size;
1139 }
1140
1141 /*
1142  * oti6858_buf_space_avail
1143  *
1144  * Return the number of bytes of space available in the circular
1145  * buffer.
1146  */
1147 static unsigned int oti6858_buf_space_avail(struct oti6858_buf *pb)
1148 {
1149         if (pb == NULL)
1150                 return 0;
1151         return (pb->buf_size + pb->buf_get - pb->buf_put - 1) % pb->buf_size;
1152 }
1153
1154 /*
1155  * oti6858_buf_put
1156  *
1157  * Copy data data from a user buffer and put it into the circular buffer.
1158  * Restrict to the amount of space available.
1159  *
1160  * Return the number of bytes copied.
1161  */
1162 static unsigned int oti6858_buf_put(struct oti6858_buf *pb, const char *buf,
1163                                         unsigned int count)
1164 {
1165         unsigned int len;
1166
1167         if (pb == NULL)
1168                 return 0;
1169
1170         len  = oti6858_buf_space_avail(pb);
1171         if (count > len)
1172                 count = len;
1173
1174         if (count == 0)
1175                 return 0;
1176
1177         len = pb->buf_buf + pb->buf_size - pb->buf_put;
1178         if (count > len) {
1179                 memcpy(pb->buf_put, buf, len);
1180                 memcpy(pb->buf_buf, buf+len, count - len);
1181                 pb->buf_put = pb->buf_buf + count - len;
1182         } else {
1183                 memcpy(pb->buf_put, buf, count);
1184                 if (count < len)
1185                         pb->buf_put += count;
1186                 else /* count == len */
1187                         pb->buf_put = pb->buf_buf;
1188         }
1189
1190         return count;
1191 }
1192
1193 /*
1194  * oti6858_buf_get
1195  *
1196  * Get data from the circular buffer and copy to the given buffer.
1197  * Restrict to the amount of data available.
1198  *
1199  * Return the number of bytes copied.
1200  */
1201 static unsigned int oti6858_buf_get(struct oti6858_buf *pb, char *buf,
1202                                         unsigned int count)
1203 {
1204         unsigned int len;
1205
1206         if (pb == NULL)
1207                 return 0;
1208
1209         len = oti6858_buf_data_avail(pb);
1210         if (count > len)
1211                 count = len;
1212
1213         if (count == 0)
1214                 return 0;
1215
1216         len = pb->buf_buf + pb->buf_size - pb->buf_get;
1217         if (count > len) {
1218                 memcpy(buf, pb->buf_get, len);
1219                 memcpy(buf+len, pb->buf_buf, count - len);
1220                 pb->buf_get = pb->buf_buf + count - len;
1221         } else {
1222                 memcpy(buf, pb->buf_get, count);
1223                 if (count < len)
1224                         pb->buf_get += count;
1225                 else /* count == len */
1226                         pb->buf_get = pb->buf_buf;
1227         }
1228
1229         return count;
1230 }
1231
1232 /* module description and (de)initialization */
1233
1234 static int __init oti6858_init(void)
1235 {
1236         int retval;
1237
1238         retval = usb_serial_register(&oti6858_device);
1239         if (retval == 0) {
1240                 retval = usb_register(&oti6858_driver);
1241                 if (retval)
1242                         usb_serial_deregister(&oti6858_device);
1243         }
1244         return retval;
1245 }
1246
1247 static void __exit oti6858_exit(void)
1248 {
1249         usb_deregister(&oti6858_driver);
1250         usb_serial_deregister(&oti6858_device);
1251 }
1252
1253 module_init(oti6858_init);
1254 module_exit(oti6858_exit);
1255
1256 MODULE_DESCRIPTION(OTI6858_DESCRIPTION);
1257 MODULE_AUTHOR(OTI6858_AUTHOR);
1258 MODULE_VERSION(OTI6858_VERSION);
1259 MODULE_LICENSE("GPL");
1260
1261 module_param(debug, bool, S_IRUGO | S_IWUSR);
1262 MODULE_PARM_DESC(debug, "enable debug output");
1263