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 driver
  29  *
  30  * TODO:
  31  *  - implement correct flushing for ioctls and oti6858_close()
  32  *  - check how errors (rx overflow, parity error, framing error) are reported
  33  *  - implement oti6858_break_ctl()
  34  *  - implement more ioctls
  35  *  - test/implement flow control
  36  *  - allow setting custom baud rates
  37  */
  38
  39 #include <linux/kernel.h>
  40 #include <linux/errno.h>
  41 #include <linux/init.h>
  42 #include <linux/slab.h>
  43 #include <linux/tty.h>
  44 #include <linux/tty_driver.h>
  45 #include <linux/tty_flip.h>
  46 #include <linux/serial.h>
  47 #include <linux/module.h>
  48 #include <linux/moduleparam.h>
  49 #include <linux/spinlock.h>
  50 #include <linux/usb.h>
  51 #include <linux/usb/serial.h>
  52 #include <asm/uaccess.h>
  53 #include "oti6858.h"
  54
  55 #define OTI6858_DESCRIPTION \
  56         "Ours Technology Inc. OTi-6858 USB to serial adapter driver"
  57 #define OTI6858_AUTHOR "Tomasz Michal Lukaszewski <FIXME@FIXME>"
  58 #define OTI6858_VERSION "0.1"
  59
  60 static struct usb_device_id id_table [] = {
  61         { USB_DEVICE(OTI6858_VENDOR_ID, OTI6858_PRODUCT_ID) },
  62         { }
  63 };
  64
  65 MODULE_DEVICE_TABLE(usb, id_table);
  66
  67 static struct usb_driver oti6858_driver = {
  68         .name =         "oti6858",
  69         .probe =        usb_serial_probe,
  70         .disconnect =   usb_serial_disconnect,
  71         .id_table =     id_table,
  72         .no_dynamic_id =        1,
  73 };
  74
  75 static int debug;
  76
  77
  78 /* buffering code, copied from pl2303 driver */
  79 #define PL2303_BUF_SIZE         1024
  80 #define PL2303_TMP_BUF_SIZE     1024
  81
  82 struct pl2303_buf {
  83         unsigned int    buf_size;
  84         char            *buf_buf;
  85         char            *buf_get;
  86         char            *buf_put;
  87 };
  88
  89 /* requests */
  90 #define OTI6858_REQ_GET_STATUS          (USB_DIR_IN | USB_TYPE_VENDOR | 0x00)
  91 #define OTI6858_REQ_T_GET_STATUS        0x01
  92
  93 #define OTI6858_REQ_SET_LINE            (USB_DIR_OUT | USB_TYPE_VENDOR | 0x00)
  94 #define OTI6858_REQ_T_SET_LINE          0x00
  95
  96 #define OTI6858_REQ_CHECK_TXBUFF        (USB_DIR_IN | USB_TYPE_VENDOR | 0x01)
  97 #define OTI6858_REQ_T_CHECK_TXBUFF      0x00
  98
  99 /* format of the control packet */
 100 struct oti6858_control_pkt {
 101         u16     divisor;        /* baud rate = 96000000 / (16 * divisor), LE */
 102 #define OTI6858_MAX_BAUD_RATE   3000000
 103         u8      frame_fmt;
 104 #define FMT_STOP_BITS_MASK      0xc0
 105 #define FMT_STOP_BITS_1         0x00
 106 #define FMT_STOP_BITS_2         0x40    /* 1.5 stop bits if FMT_DATA_BITS_5 */
 107 #define FMT_PARITY_MASK         0x38
 108 #define FMT_PARITY_NONE         0x00
 109 #define FMT_PARITY_ODD          0x08
 110 #define FMT_PARITY_EVEN         0x18
 111 #define FMT_PARITY_MARK         0x28
 112 #define FMT_PARITY_SPACE        0x38
 113 #define FMT_DATA_BITS_MASK      0x03
 114 #define FMT_DATA_BITS_5         0x00
 115 #define FMT_DATA_BITS_6         0x01
 116 #define FMT_DATA_BITS_7         0x02
 117 #define FMT_DATA_BITS_8         0x03
 118         u8      something;      /* always equals 0x43 */
 119         u8      control;        /* settings of flow control lines */
 120 #define CONTROL_MASK            0x0c
 121 #define CONTROL_DTR_HIGH        0x08
 122 #define CONTROL_RTS_HIGH        0x04
 123         u8      tx_status;
 124 #define TX_BUFFER_EMPTIED       0x09
 125         u8      pin_state;
 126 #define PIN_MASK                0x3f
 127 #define PIN_RTS                 0x20    /* output pin */
 128 #define PIN_CTS                 0x10    /* input pin, active low */
 129 #define PIN_DSR                 0x08    /* input pin, active low */
 130 #define PIN_DTR                 0x04    /* output pin */
 131 #define PIN_RI                  0x02    /* input pin, active low */
 132 #define PIN_DCD                 0x01    /* input pin, active low */
 133         u8      rx_bytes_avail;         /* number of bytes in rx buffer */;
 134 };
 135
 136 #define OTI6858_CTRL_PKT_SIZE   sizeof(struct oti6858_control_pkt)
 137 #define OTI6858_CTRL_EQUALS_PENDING(a, priv) \
 138         (    ((a)->divisor == (priv)->pending_setup.divisor) \
 139           && ((a)->control == (priv)->pending_setup.control) \
 140           && ((a)->frame_fmt == (priv)->pending_setup.frame_fmt) )
 141
 142 /* function prototypes */
 143 static int oti6858_open(struct usb_serial_port *port, struct file *filp);
 144 static void oti6858_close(struct usb_serial_port *port, struct file *filp);
 145 static void oti6858_set_termios(struct usb_serial_port *port,
 146                                 struct ktermios *old);
 147 static int oti6858_ioctl(struct usb_serial_port *port, struct file *file,
 148                         unsigned int cmd, unsigned long arg);
 149 static void oti6858_read_int_callback(struct urb *urb);
 150 static void oti6858_read_bulk_callback(struct urb *urb);
 151 static void oti6858_write_bulk_callback(struct urb *urb);
 152 static int oti6858_write(struct usb_serial_port *port,
 153                         const unsigned char *buf, int count);
 154 static int oti6858_write_room(struct usb_serial_port *port);
 155 static void oti6858_break_ctl(struct usb_serial_port *port, int break_state);
 156 static int oti6858_chars_in_buffer(struct usb_serial_port *port);
 157 static int oti6858_tiocmget(struct usb_serial_port *port, struct file *file);
 158 static int oti6858_tiocmset(struct usb_serial_port *port, struct file *file,
 159                                 unsigned int set, unsigned int clear);
 160 static int oti6858_startup(struct usb_serial *serial);
 161 static void oti6858_shutdown(struct usb_serial *serial);
 162
 163 /* functions operating on buffers */
 164 static struct pl2303_buf *pl2303_buf_alloc(unsigned int size);
 165 static void pl2303_buf_free(struct pl2303_buf *pb);
 166 static void pl2303_buf_clear(struct pl2303_buf *pb);
 167 static unsigned int pl2303_buf_data_avail(struct pl2303_buf *pb);
 168 static unsigned int pl2303_buf_space_avail(struct pl2303_buf *pb);
 169 static unsigned int pl2303_buf_put(struct pl2303_buf *pb, const char *buf,
 170                                         unsigned int count);
 171 static unsigned int pl2303_buf_get(struct pl2303_buf *pb, char *buf,
 172                                         unsigned int count);
 173
 174
 175 /* device info */
 176 static struct usb_serial_driver oti6858_device = {
 177         .driver = {
 178                 .owner =        THIS_MODULE,
 179                 .name =         "oti6858",
 180         },
 181         .id_table =             id_table,
 182         .num_interrupt_in =     1,
 183         .num_bulk_in =          1,
 184         .num_bulk_out =         1,
 185         .num_ports =            1,
 186         .open =                 oti6858_open,
 187         .close =                oti6858_close,
 188         .write =                oti6858_write,
 189         .ioctl =                oti6858_ioctl,
 190         .break_ctl =            oti6858_break_ctl,
 191         .set_termios =          oti6858_set_termios,
 192         .tiocmget =             oti6858_tiocmget,
 193         .tiocmset =             oti6858_tiocmset,
 194         .read_bulk_callback =   oti6858_read_bulk_callback,
 195         .read_int_callback =    oti6858_read_int_callback,
 196         .write_bulk_callback =  oti6858_write_bulk_callback,
 197         .write_room =           oti6858_write_room,
 198         .chars_in_buffer =      oti6858_chars_in_buffer,
 199         .attach =               oti6858_startup,
 200         .shutdown =             oti6858_shutdown,
 201 };
 202
 203 struct oti6858_private {
 204         spinlock_t lock;
 205
 206         struct pl2303_buf *buf;
 207         struct oti6858_control_pkt status;
 208
 209         struct {
 210                 u8 read_urb_in_use;
 211                 u8 write_urb_in_use;
 212                 u8 termios_initialized;
 213         } flags;
 214         struct delayed_work delayed_write_work;
 215
 216         struct {
 217                 u16 divisor;
 218                 u8 frame_fmt;
 219                 u8 control;
 220         } pending_setup;
 221         u8 transient;
 222         u8 setup_done;
 223         struct delayed_work delayed_setup_work;
 224
 225         wait_queue_head_t intr_wait;
 226         struct usb_serial_port *port;   /* USB port with which associated */
 227 };
 228
 229 #undef dbg
 230 /* #define dbg(format, arg...) printk(KERN_INFO "%s: " format "\n", __FILE__, ## arg) */
 231 #define dbg(format, arg...) printk(KERN_INFO "" format "\n", ## arg)
 232
 233 static void setup_line(struct work_struct *work)
 234 {
 235         struct oti6858_private *priv = container_of(work, struct oti6858_private, delayed_setup_work.work);
 236         struct usb_serial_port *port = priv->port;
 237         struct oti6858_control_pkt *new_setup;
 238         unsigned long flags;
 239         int result;
 240
 241         dbg("%s(port = %d)", __FUNCTION__, port->number);
 242
 243         if ((new_setup = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL)) == NULL) {
 244                 dev_err(&port->dev, "%s(): out of memory!\n", __FUNCTION__);
 245                 /* we will try again */
 246                 schedule_delayed_work(&priv->delayed_setup_work, msecs_to_jiffies(2));
 247                 return;
 248         }
 249
 250         result = usb_control_msg(port->serial->dev,
 251                                 usb_rcvctrlpipe(port->serial->dev, 0),
 252                                 OTI6858_REQ_T_GET_STATUS,
 253                                 OTI6858_REQ_GET_STATUS,
 254                                 0, 0,
 255                                 new_setup, OTI6858_CTRL_PKT_SIZE,
 256                                 100);
 257
 258         if (result != OTI6858_CTRL_PKT_SIZE) {
 259                 dev_err(&port->dev, "%s(): error reading status", __FUNCTION__);
 260                 kfree(new_setup);
 261                 /* we will try again */
 262                 schedule_delayed_work(&priv->delayed_setup_work, msecs_to_jiffies(2));
 263                 return;
 264         }
 265
 266         spin_lock_irqsave(&priv->lock, flags);
 267         if (!OTI6858_CTRL_EQUALS_PENDING(new_setup, priv)) {
 268                 new_setup->divisor = priv->pending_setup.divisor;
 269                 new_setup->control = priv->pending_setup.control;
 270                 new_setup->frame_fmt = priv->pending_setup.frame_fmt;
 271
 272                 spin_unlock_irqrestore(&priv->lock, flags);
 273                 result = usb_control_msg(port->serial->dev,
 274                                         usb_sndctrlpipe(port->serial->dev, 0),
 275                                         OTI6858_REQ_T_SET_LINE,
 276                                         OTI6858_REQ_SET_LINE,
 277                                         0, 0,
 278                                         new_setup, OTI6858_CTRL_PKT_SIZE,
 279                                         100);
 280         } else {
 281                 spin_unlock_irqrestore(&priv->lock, flags);
 282                 result = 0;
 283         }
 284         kfree(new_setup);
 285
 286         spin_lock_irqsave(&priv->lock, flags);
 287         if (result != OTI6858_CTRL_PKT_SIZE)
 288                 priv->transient = 0;
 289         priv->setup_done = 1;
 290         spin_unlock_irqrestore(&priv->lock, flags);
 291
 292         dbg("%s(): submitting interrupt urb", __FUNCTION__);
 293         port->interrupt_in_urb->dev = port->serial->dev;
 294         result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
 295         if (result != 0) {
 296                 dev_err(&port->dev, "%s(): usb_submit_urb() failed"
 297                                 " with error %d\n", __FUNCTION__, result);
 298         }
 299 }
 300
 301 void send_data(struct work_struct *work)
 302 {
 303         struct oti6858_private *priv = container_of(work, struct oti6858_private, delayed_write_work.work);
 304         struct usb_serial_port *port = priv->port;
 305         int count = 0, result;
 306         unsigned long flags;
 307         unsigned char allow;
 308
 309         dbg("%s(port = %d)", __FUNCTION__, port->number);
 310
 311         spin_lock_irqsave(&priv->lock, flags);
 312         if (priv->flags.write_urb_in_use) {
 313                 spin_unlock_irqrestore(&priv->lock, flags);
 314                 schedule_delayed_work(&priv->delayed_write_work, msecs_to_jiffies(2));
 315                 return;
 316         }
 317         priv->flags.write_urb_in_use = 1;
 318
 319         count = pl2303_buf_data_avail(priv->buf);
 320         spin_unlock_irqrestore(&priv->lock, flags);
 321         if (count > port->bulk_out_size)
 322                 count = port->bulk_out_size;
 323
 324         if (count != 0) {
 325                 result = usb_control_msg(port->serial->dev,
 326                                 usb_rcvctrlpipe(port->serial->dev, 0),
 327                                 OTI6858_REQ_T_CHECK_TXBUFF,
 328                                 OTI6858_REQ_CHECK_TXBUFF,
 329                                 count, 0, &allow, 1, 100);
 330                 if (result != 1 || allow != 0)
 331                         count = 0;
 332         }
 333
 334         if (count == 0) {
 335                 priv->flags.write_urb_in_use = 0;
 336
 337                 dbg("%s(): submitting interrupt urb", __FUNCTION__);
 338                 port->interrupt_in_urb->dev = port->serial->dev;
 339                 result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
 340                 if (result != 0) {
 341                         dev_err(&port->dev, "%s(): usb_submit_urb() failed"
 342                                 " with error %d\n", __FUNCTION__, result);
 343                 }
 344                 return;
 345         }
 346
 347         spin_lock_irqsave(&priv->lock, flags);
 348         pl2303_buf_get(priv->buf, port->write_urb->transfer_buffer, count);
 349         spin_unlock_irqrestore(&priv->lock, flags);
 350
 351         port->write_urb->transfer_buffer_length = count;
 352         port->write_urb->dev = port->serial->dev;
 353         result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
 354         if (result != 0) {
 355                 dev_err(&port->dev, "%s(): usb_submit_urb() failed"
 356                                " with error %d\n", __FUNCTION__, result);
 357                 priv->flags.write_urb_in_use = 0;
 358         }
 359
 360         usb_serial_port_softint(port);
 361 }
 362
 363 static int oti6858_startup(struct usb_serial *serial)
 364 {
 365         struct usb_serial_port *port = serial->port[0];
 366         struct oti6858_private *priv;
 367         int i;
 368
 369         for (i = 0; i < serial->num_ports; ++i) {
 370                 priv = kzalloc(sizeof(struct oti6858_private), GFP_KERNEL);
 371                 if (!priv)
 372                         break;
 373                 priv->buf = pl2303_buf_alloc(PL2303_BUF_SIZE);
 374                 if (priv->buf == NULL) {
 375                         kfree(priv);
 376                         break;
 377                 }
 378
 379                 spin_lock_init(&priv->lock);
 380                 init_waitqueue_head(&priv->intr_wait);
 381 //              INIT_WORK(&priv->setup_work, setup_line, serial->port[i]);
 382 //              INIT_WORK(&priv->write_work, send_data, serial->port[i]);
 383                 priv->port = port;
 384                 INIT_DELAYED_WORK(&priv->delayed_setup_work, setup_line);
 385                 INIT_DELAYED_WORK(&priv->delayed_write_work, send_data);
 386
 387                 usb_set_serial_port_data(serial->port[i], priv);
 388         }
 389         if (i == serial->num_ports)
 390                 return 0;
 391
 392         for (--i; i >= 0; --i) {
 393                 priv = usb_get_serial_port_data(serial->port[i]);
 394                 pl2303_buf_free(priv->buf);
 395                 kfree(priv);
 396                 usb_set_serial_port_data(serial->port[i], NULL);
 397         }
 398         return -ENOMEM;
 399 }
 400
 401 static int oti6858_write(struct usb_serial_port *port,
 402                         const unsigned char *buf, int count)
 403 {
 404         struct oti6858_private *priv = usb_get_serial_port_data(port);
 405         unsigned long flags;
 406
 407         dbg("%s(port = %d, count = %d)", __FUNCTION__, port->number, count);
 408
 409         if (!count)
 410                 return count;
 411
 412         spin_lock_irqsave(&priv->lock, flags);
 413         count = pl2303_buf_put(priv->buf, buf, count);
 414         spin_unlock_irqrestore(&priv->lock, flags);
 415
 416         return count;
 417 }
 418
 419 static int oti6858_write_room(struct usb_serial_port *port)
 420 {
 421         struct oti6858_private *priv = usb_get_serial_port_data(port);
 422         int room = 0;
 423         unsigned long flags;
 424
 425         dbg("%s(port = %d)", __FUNCTION__, port->number);
 426
 427         spin_lock_irqsave(&priv->lock, flags);
 428         room = pl2303_buf_space_avail(priv->buf);
 429         spin_unlock_irqrestore(&priv->lock, flags);
 430
 431         return room;
 432 }
 433
 434 static int oti6858_chars_in_buffer(struct usb_serial_port *port)
 435 {
 436         struct oti6858_private *priv = usb_get_serial_port_data(port);
 437         int chars = 0;
 438         unsigned long flags;
 439
 440         dbg("%s(port = %d)", __FUNCTION__, port->number);
 441
 442         spin_lock_irqsave(&priv->lock, flags);
 443         chars = pl2303_buf_data_avail(priv->buf);
 444         spin_unlock_irqrestore(&priv->lock, flags);
 445
 446         return chars;
 447 }
 448
 449 static void oti6858_set_termios(struct usb_serial_port *port,
 450                                 struct ktermios *old_termios)
 451 {
 452         struct oti6858_private *priv = usb_get_serial_port_data(port);
 453         unsigned long flags;
 454         unsigned int cflag;
 455         u8 frame_fmt, control;
 456         u16 divisor;
 457         int br;
 458
 459         dbg("%s(port = %d)", __FUNCTION__, port->number);
 460
 461         if ((!port->tty) || (!port->tty->termios)) {
 462                 dbg("%s(): no tty structures", __FUNCTION__);
 463                 return;
 464         }
 465
 466         spin_lock_irqsave(&priv->lock, flags);
 467         if (!priv->flags.termios_initialized) {
 468                 *(port->tty->termios) = tty_std_termios;
 469                 port->tty->termios->c_cflag = B38400 | CS8 | CREAD | HUPCL | CLOCAL;
 470                 priv->flags.termios_initialized = 1;
 471         }
 472         spin_unlock_irqrestore(&priv->lock, flags);
 473
 474         cflag = port->tty->termios->c_cflag;
 475
 476         spin_lock_irqsave(&priv->lock, flags);
 477         divisor = priv->pending_setup.divisor;
 478         frame_fmt = priv->pending_setup.frame_fmt;
 479         control = priv->pending_setup.control;
 480         spin_unlock_irqrestore(&priv->lock, flags);
 481
 482         frame_fmt &= ~FMT_DATA_BITS_MASK;
 483         switch (cflag & CSIZE) {
 484                 case CS5:
 485                         frame_fmt |= FMT_DATA_BITS_5;
 486                         break;
 487                 case CS6:
 488                         frame_fmt |= FMT_DATA_BITS_6;
 489                         break;
 490                 case CS7:
 491                         frame_fmt |= FMT_DATA_BITS_7;
 492                         break;
 493                 default:
 494                 case CS8:
 495                         frame_fmt |= FMT_DATA_BITS_8;
 496                         break;
 497         }
 498
 499         /* manufacturer claims that this device can work with baud rates
 500          * up to 3 Mbps; I've tested it only on 115200 bps, so I can't
 501          * guarantee that any other baud rate will work (especially
 502          * the higher ones)
 503          */
 504         br = tty_get_baud_rate(port->tty);
 505         if (br == 0) {
 506                 divisor = 0;
 507         } else if (br <= OTI6858_MAX_BAUD_RATE) {
 508                 int real_br;
 509
 510                 divisor = (96000000 + 8 * br) / (16 * br);
 511                 real_br = 96000000 / (16 * divisor);
 512                 if ((((real_br - br) * 100 + br - 1) / br) > 2) {
 513                         dbg("%s(): baud rate %d is invalid", __FUNCTION__, br);
 514                         return;
 515                 }
 516                 divisor = cpu_to_le16(divisor);
 517         } else {
 518                 dbg("%s(): baud rate %d is too high", __FUNCTION__, br);
 519                 return;
 520         }
 521
 522         frame_fmt &= ~FMT_STOP_BITS_MASK;
 523         if ((cflag & CSTOPB) != 0) {
 524                 frame_fmt |= FMT_STOP_BITS_2;
 525         } else {
 526                 frame_fmt |= FMT_STOP_BITS_1;
 527         }
 528
 529         frame_fmt &= ~FMT_PARITY_MASK;
 530         if ((cflag & PARENB) != 0) {
 531                 if ((cflag & PARODD) != 0) {
 532                         frame_fmt |= FMT_PARITY_ODD;
 533                 } else {
 534                         frame_fmt |= FMT_PARITY_EVEN;
 535                 }
 536         } else {
 537                 frame_fmt |= FMT_PARITY_NONE;
 538         }
 539
 540         control &= ~CONTROL_MASK;
 541         if ((cflag & CRTSCTS) != 0)
 542                 control |= (CONTROL_DTR_HIGH | CONTROL_RTS_HIGH);
 543
 544         /* change control lines if we are switching to or from B0 */
 545         /* FIXME:
 546         spin_lock_irqsave(&priv->lock, flags);
 547         control = priv->line_control;
 548         if ((cflag & CBAUD) == B0)
 549                 priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
 550         else
 551                 priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
 552         if (control != priv->line_control) {
 553                 control = priv->line_control;
 554                 spin_unlock_irqrestore(&priv->lock, flags);
 555                 set_control_lines(serial->dev, control);
 556         } else {
 557                 spin_unlock_irqrestore(&priv->lock, flags);
 558         }
 559         */
 560
 561         spin_lock_irqsave(&priv->lock, flags);
 562         if (divisor != priv->pending_setup.divisor
 563                         || control != priv->pending_setup.control
 564                         || frame_fmt != priv->pending_setup.frame_fmt) {
 565                 priv->pending_setup.divisor = divisor;
 566                 priv->pending_setup.control = control;
 567                 priv->pending_setup.frame_fmt = frame_fmt;
 568         }
 569         spin_unlock_irqrestore(&priv->lock, flags);
 570 }
 571
 572 static int oti6858_open(struct usb_serial_port *port, struct file *filp)
 573 {
 574         struct oti6858_private *priv = usb_get_serial_port_data(port);
 575         struct ktermios tmp_termios;
 576         struct usb_serial *serial = port->serial;
 577         struct oti6858_control_pkt *buf;
 578         unsigned long flags;
 579         int result;
 580
 581         dbg("%s(port = %d)", __FUNCTION__, port->number);
 582
 583         usb_clear_halt(serial->dev, port->write_urb->pipe);
 584         usb_clear_halt(serial->dev, port->read_urb->pipe);
 585
 586         if (port->open_count != 1)
 587                 return 0;
 588
 589         if ((buf = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL)) == NULL) {
 590                 dev_err(&port->dev, "%s(): out of memory!\n", __FUNCTION__);
 591                 return -ENOMEM;
 592         }
 593
 594         result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
 595                                 OTI6858_REQ_T_GET_STATUS,
 596                                 OTI6858_REQ_GET_STATUS,
 597                                 0, 0,
 598                                 buf, OTI6858_CTRL_PKT_SIZE,
 599                                 100);
 600         if (result != OTI6858_CTRL_PKT_SIZE) {
 601                 /* assume default (after power-on reset) values */
 602                 buf->divisor = cpu_to_le16(0x009c);     /* 38400 bps */
 603                 buf->frame_fmt = 0x03;  /* 8N1 */
 604                 buf->something = 0x43;
 605                 buf->control = 0x4c;    /* DTR, RTS */
 606                 buf->tx_status = 0x00;
 607                 buf->pin_state = 0x5b;  /* RTS, CTS, DSR, DTR, RI, DCD */
 608                 buf->rx_bytes_avail = 0x00;
 609         }
 610
 611         spin_lock_irqsave(&priv->lock, flags);
 612         memcpy(&priv->status, buf, OTI6858_CTRL_PKT_SIZE);
 613         priv->pending_setup.divisor = buf->divisor;
 614         priv->pending_setup.frame_fmt = buf->frame_fmt;
 615         priv->pending_setup.control = buf->control;
 616         spin_unlock_irqrestore(&priv->lock, flags);
 617         kfree(buf);
 618
 619         dbg("%s(): submitting interrupt urb", __FUNCTION__);
 620         port->interrupt_in_urb->dev = serial->dev;
 621         result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 622         if (result != 0) {
 623                 dev_err(&port->dev, "%s(): usb_submit_urb() failed"
 624                                " with error %d\n", __FUNCTION__, result);
 625                 oti6858_close(port, NULL);
 626                 return -EPROTO;
 627         }
 628
 629         /* setup termios */
 630         if (port->tty)
 631                 oti6858_set_termios(port, &tmp_termios);
 632
 633         return 0;
 634 }
 635
 636 static void oti6858_close(struct usb_serial_port *port, struct file *filp)
 637 {
 638         struct oti6858_private *priv = usb_get_serial_port_data(port);
 639         unsigned long flags;
 640         long timeout;
 641         wait_queue_t wait;
 642
 643         dbg("%s(port = %d)", __FUNCTION__, port->number);
 644
 645         /* wait for data to drain from the buffer */
 646         spin_lock_irqsave(&priv->lock, flags);
 647         timeout = 30 * HZ;      /* PL2303_CLOSING_WAIT */
 648         init_waitqueue_entry(&wait, current);
 649         add_wait_queue(&port->tty->write_wait, &wait);
 650         dbg("%s(): entering wait loop", __FUNCTION__);
 651         for (;;) {
 652                 set_current_state(TASK_INTERRUPTIBLE);
 653                 if (pl2303_buf_data_avail(priv->buf) == 0
 654                 || timeout == 0 || signal_pending(current)
 655                 || !usb_get_intfdata(port->serial->interface))  /* disconnect */
 656                         break;
 657                 spin_unlock_irqrestore(&priv->lock, flags);
 658                 timeout = schedule_timeout(timeout);
 659                 spin_lock_irqsave(&priv->lock, flags);
 660         }
 661         set_current_state(TASK_RUNNING);
 662         remove_wait_queue(&port->tty->write_wait, &wait);
 663         dbg("%s(): after wait loop", __FUNCTION__);
 664
 665         /* clear out any remaining data in the buffer */
 666         pl2303_buf_clear(priv->buf);
 667         spin_unlock_irqrestore(&priv->lock, flags);
 668
 669         /* wait for characters to drain from the device */
 670         /* (this is long enough for the entire 256 byte */
 671         /* pl2303 hardware buffer to drain with no flow */
 672         /* control for data rates of 1200 bps or more, */
 673         /* for lower rates we should really know how much */
 674         /* data is in the buffer to compute a delay */
 675         /* that is not unnecessarily long) */
 676         /* FIXME
 677         bps = tty_get_baud_rate(port->tty);
 678         if (bps > 1200)
 679                 timeout = max((HZ*2560)/bps,HZ/10);
 680         else
 681         */
 682                 timeout = 2*HZ;
 683         schedule_timeout_interruptible(timeout);
 684         dbg("%s(): after schedule_timeout_interruptible()", __FUNCTION__);
 685
 686         /* cancel scheduled setup */
 687         cancel_delayed_work(&priv->delayed_setup_work);
 688         cancel_delayed_work(&priv->delayed_write_work);
 689         flush_scheduled_work();
 690
 691         /* shutdown our urbs */
 692         dbg("%s(): shutting down urbs", __FUNCTION__);
 693         usb_kill_urb(port->write_urb);
 694         usb_kill_urb(port->read_urb);
 695         usb_kill_urb(port->interrupt_in_urb);
 696
 697         /*
 698         if (port->tty && (port->tty->termios->c_cflag) & HUPCL) {
 699                 // drop DTR and RTS
 700                 spin_lock_irqsave(&priv->lock, flags);
 701                 priv->pending_setup.control &= ~CONTROL_MASK;
 702                 spin_unlock_irqrestore(&priv->lock, flags);
 703         }
 704         */
 705 }
 706
 707 static int oti6858_tiocmset(struct usb_serial_port *port, struct file *file,
 708                                 unsigned int set, unsigned int clear)
 709 {
 710         struct oti6858_private *priv = usb_get_serial_port_data(port);
 711         unsigned long flags;
 712         u8 control;
 713
 714         dbg("%s(port = %d, set = 0x%08x, clear = 0x%08x)",
 715                                 __FUNCTION__, port->number, set, clear);
 716
 717         if (!usb_get_intfdata(port->serial->interface))
 718                 return -ENODEV;
 719
 720         /* FIXME: check if this is correct (active high/low) */
 721         spin_lock_irqsave(&priv->lock, flags);
 722         control = priv->pending_setup.control;
 723         if ((set & TIOCM_RTS) != 0)
 724                 control |= CONTROL_RTS_HIGH;
 725         if ((set & TIOCM_DTR) != 0)
 726                 control |= CONTROL_DTR_HIGH;
 727         if ((clear & TIOCM_RTS) != 0)
 728                 control &= ~CONTROL_RTS_HIGH;
 729         if ((clear & TIOCM_DTR) != 0)
 730                 control &= ~CONTROL_DTR_HIGH;
 731
 732         if (control != priv->pending_setup.control) {
 733                 priv->pending_setup.control = control;
 734         }
 735         spin_unlock_irqrestore(&priv->lock, flags);
 736
 737         return 0;
 738 }
 739
 740 static int oti6858_tiocmget(struct usb_serial_port *port, struct file *file)
 741 {
 742         struct oti6858_private *priv = usb_get_serial_port_data(port);
 743         unsigned long flags;
 744         unsigned pin_state;
 745         unsigned result = 0;
 746
 747         dbg("%s(port = %d)", __FUNCTION__, port->number);
 748
 749         if (!usb_get_intfdata(port->serial->interface))
 750                 return -ENODEV;
 751
 752         spin_lock_irqsave(&priv->lock, flags);
 753         pin_state = priv->status.pin_state & PIN_MASK;
 754         spin_unlock_irqrestore(&priv->lock, flags);
 755
 756         /* FIXME: check if this is correct (active high/low) */
 757         if ((pin_state & PIN_RTS) != 0)
 758                 result |= TIOCM_RTS;
 759         if ((pin_state & PIN_CTS) != 0)
 760                 result |= TIOCM_CTS;
 761         if ((pin_state & PIN_DSR) != 0)
 762                 result |= TIOCM_DSR;
 763         if ((pin_state & PIN_DTR) != 0)
 764                 result |= TIOCM_DTR;
 765         if ((pin_state & PIN_RI) != 0)
 766                 result |= TIOCM_RI;
 767         if ((pin_state & PIN_DCD) != 0)
 768                 result |= TIOCM_CD;
 769
 770         dbg("%s() = 0x%08x", __FUNCTION__, result);
 771
 772         return result;
 773 }
 774
 775 static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
 776 {
 777         struct oti6858_private *priv = usb_get_serial_port_data(port);
 778         unsigned long flags;
 779         unsigned int prev, status;
 780         unsigned int changed;
 781
 782         spin_lock_irqsave(&priv->lock, flags);
 783         prev = priv->status.pin_state;
 784         spin_unlock_irqrestore(&priv->lock, flags);
 785
 786         while (1) {
 787                 wait_event_interruptible(priv->intr_wait, priv->status.pin_state != prev);
 788                 if (signal_pending(current))
 789                         return -ERESTARTSYS;
 790
 791                 spin_lock_irqsave(&priv->lock, flags);
 792                 status = priv->status.pin_state & PIN_MASK;
 793                 spin_unlock_irqrestore(&priv->lock, flags);
 794
 795                 changed = prev ^ status;
 796                 /* FIXME: check if this is correct (active high/low) */
 797                 if (    ((arg & TIOCM_RNG) && (changed & PIN_RI)) ||
 798                         ((arg & TIOCM_DSR) && (changed & PIN_DSR)) ||
 799                         ((arg & TIOCM_CD)  && (changed & PIN_DCD)) ||
 800                         ((arg & TIOCM_CTS) && (changed & PIN_CTS))) {
 801                                 return 0;
 802                 }
 803                 prev = status;
 804         }
 805
 806         /* NOTREACHED */
 807         return 0;
 808 }
 809
 810 static int oti6858_ioctl(struct usb_serial_port *port, struct file *file,
 811                         unsigned int cmd, unsigned long arg)
 812 {
 813         void __user *user_arg = (void __user *) arg;
 814         unsigned int x;
 815
 816         dbg("%s(port = %d, cmd = 0x%04x, arg = 0x%08lx)",
 817                                 __FUNCTION__, port->number, cmd, arg);
 818
 819         switch (cmd) {
 820                 case TCFLSH:
 821                         /* FIXME */
 822                         return 0;
 823
 824                 case TIOCMBIS:
 825                         if (copy_from_user(&x, user_arg, sizeof(x)))
 826                                 return -EFAULT;
 827                         return oti6858_tiocmset(port, NULL, x, 0);
 828
 829                 case TIOCMBIC:
 830                         if (copy_from_user(&x, user_arg, sizeof(x)))
 831                                 return -EFAULT;
 832                         return oti6858_tiocmset(port, NULL, 0, x);
 833
 834                 case TIOCGSERIAL:
 835                         if (copy_to_user(user_arg, port->tty->termios,
 836                                                 sizeof(struct ktermios))) {
 837                                 return -EFAULT;
 838                         }
 839                         return 0;
 840
 841                 case TIOCSSERIAL:
 842                         if (copy_from_user(port->tty->termios, user_arg,
 843                                                 sizeof(struct ktermios))) {
 844                                 return -EFAULT;
 845                         }
 846                         oti6858_set_termios(port, NULL);
 847                         return 0;
 848
 849                 case TIOCMIWAIT:
 850                         dbg("%s(): TIOCMIWAIT", __FUNCTION__);
 851                         return wait_modem_info(port, arg);
 852
 853                 default:
 854                         dbg("%s(): 0x%04x not supported", __FUNCTION__, cmd);
 855                         break;
 856         }
 857
 858         return -ENOIOCTLCMD;
 859 }
 860
 861 static void oti6858_break_ctl(struct usb_serial_port *port, int break_state)
 862 {
 863         int state;
 864
 865         dbg("%s(port = %d)", __FUNCTION__, port->number);
 866
 867         state = (break_state == 0) ? 0 : 1;
 868         dbg("%s(): turning break %s", __FUNCTION__, state ? "on" : "off");
 869
 870         /* FIXME */
 871 /*
 872         result = usb_control_msg (serial->dev, usb_sndctrlpipe (serial->dev, 0),
 873                                   BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
 874                                   0, NULL, 0, 100);
 875         if (result != 0)
 876                 dbg("%s(): error sending break", __FUNCTION__);
 877  */
 878 }
 879
 880 static void oti6858_shutdown(struct usb_serial *serial)
 881 {
 882         struct oti6858_private *priv;
 883         int i;
 884
 885         dbg("%s()", __FUNCTION__);
 886
 887         for (i = 0; i < serial->num_ports; ++i) {
 888                 priv = usb_get_serial_port_data(serial->port[i]);
 889                 if (priv) {
 890                         pl2303_buf_free(priv->buf);
 891                         kfree(priv);
 892                         usb_set_serial_port_data(serial->port[i], NULL);
 893                 }
 894         }
 895 }
 896
 897 static void oti6858_read_int_callback(struct urb *urb)
 898 {
 899         struct usb_serial_port *port = (struct usb_serial_port *) urb->context;
 900         struct oti6858_private *priv = usb_get_serial_port_data(port);
 901         int transient = 0, can_recv = 0, resubmit = 1;
 902         int status = urb->status;
 903
 904         dbg("%s(port = %d, status = %d)",
 905                                 __FUNCTION__, port->number, status);
 906
 907         switch (status) {
 908         case 0:
 909                 /* success */
 910                 break;
 911         case -ECONNRESET:
 912         case -ENOENT:
 913         case -ESHUTDOWN:
 914                 /* this urb is terminated, clean up */
 915                 dbg("%s(): urb shutting down with status: %d",
 916                                         __FUNCTION__, status);
 917                 return;
 918         default:
 919                 dbg("%s(): nonzero urb status received: %d",
 920                                         __FUNCTION__, status);
 921                 break;
 922         }
 923
 924         if (status == 0 && urb->actual_length == OTI6858_CTRL_PKT_SIZE) {
 925                 struct oti6858_control_pkt *xs = urb->transfer_buffer;
 926                 unsigned long flags;
 927
 928                 spin_lock_irqsave(&priv->lock, flags);
 929
 930                 if (!priv->transient) {
 931                         if (!OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
 932                                 if (xs->rx_bytes_avail == 0) {
 933                                         priv->transient = 4;
 934                                         priv->setup_done = 0;
 935                                         resubmit = 0;
 936                                         dbg("%s(): scheduling setup_line()",
 937                                             __FUNCTION__);
 938                                         schedule_delayed_work(&priv->delayed_setup_work, 0);
 939                                 }
 940                         }
 941                 } else {
 942                         if (OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
 943                                 priv->transient = 0;
 944                         } else if (!priv->setup_done) {
 945                                 resubmit = 0;
 946                         } else if (--priv->transient == 0) {
 947                                 if (xs->rx_bytes_avail == 0) {
 948                                         priv->transient = 4;
 949                                         priv->setup_done = 0;
 950                                         resubmit = 0;
 951                                         dbg("%s(): scheduling setup_line()",
 952                                             __FUNCTION__);
 953                                         schedule_delayed_work(&priv->delayed_setup_work, 0);
 954                                 }
 955                         }
 956                 }
 957
 958                 if (!priv->transient) {
 959                         if (xs->pin_state != priv->status.pin_state)
 960                                 wake_up_interruptible(&priv->intr_wait);
 961                         memcpy(&priv->status, xs, OTI6858_CTRL_PKT_SIZE);
 962                 }
 963
 964                 if (!priv->transient && xs->rx_bytes_avail != 0) {
 965                         can_recv = xs->rx_bytes_avail;
 966                         priv->flags.read_urb_in_use = 1;
 967                 }
 968
 969                 transient = priv->transient;
 970                 spin_unlock_irqrestore(&priv->lock, flags);
 971         }
 972
 973         if (can_recv) {
 974                 int result;
 975
 976                 port->read_urb->dev = port->serial->dev;
 977                 result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
 978                 if (result != 0) {
 979                         priv->flags.read_urb_in_use = 0;
 980                         dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
 981                                         " error %d\n", __FUNCTION__, result);
 982                 } else {
 983                         resubmit = 0;
 984                 }
 985         } else if (!transient) {
 986                 unsigned long flags;
 987
 988                 spin_lock_irqsave(&priv->lock, flags);
 989                 if (priv->flags.write_urb_in_use == 0
 990                                 && pl2303_buf_data_avail(priv->buf) != 0) {
 991                         schedule_delayed_work(&priv->delayed_write_work,0);
 992                         resubmit = 0;
 993                 }
 994                 spin_unlock_irqrestore(&priv->lock, flags);
 995         }
 996
 997         if (resubmit) {
 998                 int result;
 999
1000 //              dbg("%s(): submitting interrupt urb", __FUNCTION__);
1001                 urb->dev = port->serial->dev;
1002                 result = usb_submit_urb(urb, GFP_ATOMIC);
1003                 if (result != 0) {
1004                         dev_err(&urb->dev->dev,
1005                                         "%s(): usb_submit_urb() failed with"
1006                                         " error %d\n", __FUNCTION__, result);
1007                 }
1008         }
1009 }
1010
1011 static void oti6858_read_bulk_callback(struct urb *urb)
1012 {
1013         struct usb_serial_port *port = (struct usb_serial_port *) urb->context;
1014         struct oti6858_private *priv = usb_get_serial_port_data(port);
1015         struct tty_struct *tty;
1016         unsigned char *data = urb->transfer_buffer;
1017         unsigned long flags;
1018         int i, result;
1019         int status = urb->status;
1020         char tty_flag;
1021
1022         dbg("%s(port = %d, status = %d)",
1023                                 __FUNCTION__, port->number, status);
1024
1025         spin_lock_irqsave(&priv->lock, flags);
1026         priv->flags.read_urb_in_use = 0;
1027         spin_unlock_irqrestore(&priv->lock, flags);
1028
1029         if (status != 0) {
1030                 if (!port->open_count) {
1031                         dbg("%s(): port is closed, exiting", __FUNCTION__);
1032                         return;
1033                 }
1034                 /*
1035                 if (status == -EPROTO) {
1036                         // PL2303 mysteriously fails with -EPROTO reschedule the read
1037                         dbg("%s - caught -EPROTO, resubmitting the urb", __FUNCTION__);
1038                         result = usb_submit_urb(urb, GFP_ATOMIC);
1039                         if (result)
1040                                 dev_err(&urb->dev->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
1041                         return;
1042                 }
1043                 */
1044                 dbg("%s(): unable to handle the error, exiting", __FUNCTION__);
1045                 return;
1046         }
1047
1048         // get tty_flag from status
1049         tty_flag = TTY_NORMAL;
1050
1051 /* FIXME: probably, errors will be signalled using interrupt pipe! */
1052 /*
1053         // break takes precedence over parity,
1054         // which takes precedence over framing errors
1055         if (status & UART_BREAK_ERROR )
1056                 tty_flag = TTY_BREAK;
1057         else if (status & UART_PARITY_ERROR)
1058                 tty_flag = TTY_PARITY;
1059         else if (status & UART_FRAME_ERROR)
1060                 tty_flag = TTY_FRAME;
1061         dbg("%s - tty_flag = %d", __FUNCTION__, tty_flag);
1062 */
1063
1064         tty = port->tty;
1065         if (tty != NULL && urb->actual_length > 0) {
1066                 tty_buffer_request_room(tty, urb->actual_length);
1067                 for (i = 0; i < urb->actual_length; ++i)
1068                         tty_insert_flip_char(tty, data[i], tty_flag);
1069                 tty_flip_buffer_push(tty);
1070         }
1071
1072         // schedule the interrupt urb if we are still open */
1073         if (port->open_count != 0) {
1074                 port->interrupt_in_urb->dev = port->serial->dev;
1075                 result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1076                 if (result != 0) {
1077                         dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
1078                                         " error %d\n", __FUNCTION__, result);
1079                 }
1080         }
1081 }
1082
1083 static void oti6858_write_bulk_callback(struct urb *urb)
1084 {
1085         struct usb_serial_port *port = (struct usb_serial_port *) urb->context;
1086         struct oti6858_private *priv = usb_get_serial_port_data(port);
1087         int status = urb->status;
1088         int result;
1089
1090         dbg("%s(port = %d, status = %d)",
1091                                 __FUNCTION__, port->number, status);
1092
1093         switch (status) {
1094         case 0:
1095                 /* success */
1096                 break;
1097         case -ECONNRESET:
1098         case -ENOENT:
1099         case -ESHUTDOWN:
1100                 /* this urb is terminated, clean up */
1101                 dbg("%s(): urb shutting down with status: %d",
1102                                         __FUNCTION__, status);
1103                 priv->flags.write_urb_in_use = 0;
1104                 return;
1105         default:
1106                 /* error in the urb, so we have to resubmit it */
1107                 dbg("%s(): nonzero write bulk status received: %d",
1108                                         __FUNCTION__, status);
1109                 dbg("%s(): overflow in write", __FUNCTION__);
1110
1111                 port->write_urb->transfer_buffer_length = 1;
1112                 port->write_urb->dev = port->serial->dev;
1113                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
1114                 if (result) {
1115                         dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
1116                                         " error %d\n", __FUNCTION__, result);
1117                 } else {
1118                         return;
1119                 }
1120         }
1121
1122         priv->flags.write_urb_in_use = 0;
1123
1124         // schedule the interrupt urb if we are still open */
1125         port->interrupt_in_urb->dev = port->serial->dev;
1126         dbg("%s(): submitting interrupt urb", __FUNCTION__);
1127         result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1128         if (result != 0) {
1129                 dev_err(&port->dev, "%s(): failed submitting int urb,"
1130                                         " error %d\n", __FUNCTION__, result);
1131         }
1132 }
1133
1134
1135 /*
1136  * pl2303_buf_alloc
1137  *
1138  * Allocate a circular buffer and all associated memory.
1139  */
1140 static struct pl2303_buf *pl2303_buf_alloc(unsigned int size)
1141 {
1142         struct pl2303_buf *pb;
1143
1144         if (size == 0)
1145                 return NULL;
1146
1147         pb = (struct pl2303_buf *)kmalloc(sizeof(struct pl2303_buf), GFP_KERNEL);
1148         if (pb == NULL)
1149                 return NULL;
1150
1151         pb->buf_buf = kmalloc(size, GFP_KERNEL);
1152         if (pb->buf_buf == NULL) {
1153                 kfree(pb);
1154                 return NULL;
1155         }
1156
1157         pb->buf_size = size;
1158         pb->buf_get = pb->buf_put = pb->buf_buf;
1159
1160         return pb;
1161 }
1162
1163 /*
1164  * pl2303_buf_free
1165  *
1166  * Free the buffer and all associated memory.
1167  */
1168 static void pl2303_buf_free(struct pl2303_buf *pb)
1169 {
1170         if (pb) {
1171                 kfree(pb->buf_buf);
1172                 kfree(pb);
1173         }
1174 }
1175
1176 /*
1177  * pl2303_buf_clear
1178  *
1179  * Clear out all data in the circular buffer.
1180  */
1181 static void pl2303_buf_clear(struct pl2303_buf *pb)
1182 {
1183         if (pb != NULL) {
1184                 /* equivalent to a get of all data available */
1185                 pb->buf_get = pb->buf_put;
1186         }
1187 }
1188
1189 /*
1190  * pl2303_buf_data_avail
1191  *
1192  * Return the number of bytes of data available in the circular
1193  * buffer.
1194  */
1195 static unsigned int pl2303_buf_data_avail(struct pl2303_buf *pb)
1196 {
1197         if (pb == NULL)
1198                 return 0;
1199         return ((pb->buf_size + pb->buf_put - pb->buf_get) % pb->buf_size);
1200 }
1201
1202 /*
1203  * pl2303_buf_space_avail
1204  *
1205  * Return the number of bytes of space available in the circular
1206  * buffer.
1207  */
1208 static unsigned int pl2303_buf_space_avail(struct pl2303_buf *pb)
1209 {
1210         if (pb == NULL)
1211                 return 0;
1212         return ((pb->buf_size + pb->buf_get - pb->buf_put - 1) % pb->buf_size);
1213 }
1214
1215 /*
1216  * pl2303_buf_put
1217  *
1218  * Copy data data from a user buffer and put it into the circular buffer.
1219  * Restrict to the amount of space available.
1220  *
1221  * Return the number of bytes copied.
1222  */
1223 static unsigned int pl2303_buf_put(struct pl2303_buf *pb, const char *buf,
1224                                         unsigned int count)
1225 {
1226         unsigned int len;
1227
1228         if (pb == NULL)
1229                 return 0;
1230
1231         len  = pl2303_buf_space_avail(pb);
1232         if (count > len)
1233                 count = len;
1234
1235         if (count == 0)
1236                 return 0;
1237
1238         len = pb->buf_buf + pb->buf_size - pb->buf_put;
1239         if (count > len) {
1240                 memcpy(pb->buf_put, buf, len);
1241                 memcpy(pb->buf_buf, buf+len, count - len);
1242                 pb->buf_put = pb->buf_buf + count - len;
1243         } else {
1244                 memcpy(pb->buf_put, buf, count);
1245                 if (count < len)
1246                         pb->buf_put += count;
1247                 else /* count == len */
1248                         pb->buf_put = pb->buf_buf;
1249         }
1250
1251         return count;
1252 }
1253
1254 /*
1255  * pl2303_buf_get
1256  *
1257  * Get data from the circular buffer and copy to the given buffer.
1258  * Restrict to the amount of data available.
1259  *
1260  * Return the number of bytes copied.
1261  */
1262 static unsigned int pl2303_buf_get(struct pl2303_buf *pb, char *buf,
1263                                         unsigned int count)
1264 {
1265         unsigned int len;
1266
1267         if (pb == NULL)
1268                 return 0;
1269
1270         len = pl2303_buf_data_avail(pb);
1271         if (count > len)
1272                 count = len;
1273
1274         if (count == 0)
1275                 return 0;
1276
1277         len = pb->buf_buf + pb->buf_size - pb->buf_get;
1278         if (count > len) {
1279                 memcpy(buf, pb->buf_get, len);
1280                 memcpy(buf+len, pb->buf_buf, count - len);
1281                 pb->buf_get = pb->buf_buf + count - len;
1282         } else {
1283                 memcpy(buf, pb->buf_get, count);
1284                 if (count < len)
1285                         pb->buf_get += count;
1286                 else /* count == len */
1287                         pb->buf_get = pb->buf_buf;
1288         }
1289
1290         return count;
1291 }
1292
1293 /* module description and (de)initialization */
1294
1295 static int __init oti6858_init(void)
1296 {
1297         int retval;
1298
1299         if ((retval = usb_serial_register(&oti6858_device)) == 0) {
1300                 if ((retval = usb_register(&oti6858_driver)) != 0)
1301                         usb_serial_deregister(&oti6858_device);
1302                 else
1303                         return 0;
1304         }
1305
1306         return retval;
1307 }
1308
1309 static void __exit oti6858_exit(void)
1310 {
1311         usb_deregister(&oti6858_driver);
1312         usb_serial_deregister(&oti6858_device);
1313 }
1314
1315 module_init(oti6858_init);
1316 module_exit(oti6858_exit);
1317
1318 MODULE_DESCRIPTION(OTI6858_DESCRIPTION);
1319 MODULE_AUTHOR(OTI6858_AUTHOR);
1320 MODULE_VERSION(OTI6858_VERSION);
1321 MODULE_LICENSE("GPL");
1322
1323 module_param(debug, bool, S_IRUGO | S_IWUSR);
1324 MODULE_PARM_DESC(debug, "enable debug output");
1325