drivers/usb/serial/oti6858.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Ours Technology Inc. OTi-6858 USB to serial adapter driver.
   4  *
   5  * Copyleft  (C) 2007 Kees Lemmens (adapted for kernel 2.6.20)
   6  * Copyright (C) 2006 Tomasz Michal Lukaszewski (FIXME: add e-mail)
   7  * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com)
   8  * Copyright (C) 2003 IBM Corp.
   9  *
  10  * Many thanks to the authors of pl2303 driver: all functions in this file
  11  * are heavily based on pl2303 code, buffering code is a 1-to-1 copy.
  12  *
  13  * Warning! You use this driver on your own risk! The only official
  14  * description of this device I have is datasheet from manufacturer,
  15  * and it doesn't contain almost any information needed to write a driver.
  16  * Almost all knowlegde used while writing this driver was gathered by:
  17  *  - analyzing traffic between device and the M$ Windows 2000 driver,
  18  *  - trying different bit combinations and checking pin states
  19  *    with a voltmeter,
  20  *  - receiving malformed frames and producing buffer overflows
  21  *    to learn how errors are reported,
  22  * So, THIS CODE CAN DESTROY OTi-6858 AND ANY OTHER DEVICES, THAT ARE
  23  * CONNECTED TO IT!
  24  *
  25  * See Documentation/usb/usb-serial.rst for more information on using this
  26  * driver
  27  *
  28  * TODO:
  29  *  - implement correct flushing for ioctls and oti6858_close()
  30  *  - check how errors (rx overflow, parity error, framing error) are reported
  31  *  - implement oti6858_break_ctl()
  32  *  - implement more ioctls
  33  *  - test/implement flow control
  34  *  - allow setting custom baud rates
  35  */
  36
  37 #include <linux/kernel.h>
  38 #include <linux/errno.h>
  39 #include <linux/slab.h>
  40 #include <linux/tty.h>
  41 #include <linux/tty_driver.h>
  42 #include <linux/tty_flip.h>
  43 #include <linux/serial.h>
  44 #include <linux/module.h>
  45 #include <linux/moduleparam.h>
  46 #include <linux/spinlock.h>
  47 #include <linux/usb.h>
  48 #include <linux/usb/serial.h>
  49 #include <linux/uaccess.h>
  50 #include <linux/kfifo.h>
  51 #include "oti6858.h"
  52
  53 #define OTI6858_DESCRIPTION \
  54         "Ours Technology Inc. OTi-6858 USB to serial adapter driver"
  55 #define OTI6858_AUTHOR "Tomasz Michal Lukaszewski <FIXME@FIXME>"
  56
  57 static const struct usb_device_id id_table[] = {
  58         { USB_DEVICE(OTI6858_VENDOR_ID, OTI6858_PRODUCT_ID) },
  59         { }
  60 };
  61
  62 MODULE_DEVICE_TABLE(usb, id_table);
  63
  64 /* requests */
  65 #define OTI6858_REQ_GET_STATUS          (USB_DIR_IN | USB_TYPE_VENDOR | 0x00)
  66 #define OTI6858_REQ_T_GET_STATUS        0x01
  67
  68 #define OTI6858_REQ_SET_LINE            (USB_DIR_OUT | USB_TYPE_VENDOR | 0x00)
  69 #define OTI6858_REQ_T_SET_LINE          0x00
  70
  71 #define OTI6858_REQ_CHECK_TXBUFF        (USB_DIR_IN | USB_TYPE_VENDOR | 0x01)
  72 #define OTI6858_REQ_T_CHECK_TXBUFF      0x00
  73
  74 /* format of the control packet */
  75 struct oti6858_control_pkt {
  76         __le16  divisor;        /* baud rate = 96000000 / (16 * divisor), LE */
  77 #define OTI6858_MAX_BAUD_RATE   3000000
  78         u8      frame_fmt;
  79 #define FMT_STOP_BITS_MASK      0xc0
  80 #define FMT_STOP_BITS_1         0x00
  81 #define FMT_STOP_BITS_2         0x40    /* 1.5 stop bits if FMT_DATA_BITS_5 */
  82 #define FMT_PARITY_MASK         0x38
  83 #define FMT_PARITY_NONE         0x00
  84 #define FMT_PARITY_ODD          0x08
  85 #define FMT_PARITY_EVEN         0x18
  86 #define FMT_PARITY_MARK         0x28
  87 #define FMT_PARITY_SPACE        0x38
  88 #define FMT_DATA_BITS_MASK      0x03
  89 #define FMT_DATA_BITS_5         0x00
  90 #define FMT_DATA_BITS_6         0x01
  91 #define FMT_DATA_BITS_7         0x02
  92 #define FMT_DATA_BITS_8         0x03
  93         u8      something;      /* always equals 0x43 */
  94         u8      control;        /* settings of flow control lines */
  95 #define CONTROL_MASK            0x0c
  96 #define CONTROL_DTR_HIGH        0x08
  97 #define CONTROL_RTS_HIGH        0x04
  98         u8      tx_status;
  99 #define TX_BUFFER_EMPTIED       0x09
 100         u8      pin_state;
 101 #define PIN_MASK                0x3f
 102 #define PIN_MSR_MASK            0x1b
 103 #define PIN_RTS                 0x20    /* output pin */
 104 #define PIN_CTS                 0x10    /* input pin, active low */
 105 #define PIN_DSR                 0x08    /* input pin, active low */
 106 #define PIN_DTR                 0x04    /* output pin */
 107 #define PIN_RI                  0x02    /* input pin, active low */
 108 #define PIN_DCD                 0x01    /* input pin, active low */
 109         u8      rx_bytes_avail;         /* number of bytes in rx buffer */;
 110 };
 111
 112 #define OTI6858_CTRL_PKT_SIZE   sizeof(struct oti6858_control_pkt)
 113 #define OTI6858_CTRL_EQUALS_PENDING(a, priv) \
 114         (((a)->divisor == (priv)->pending_setup.divisor) \
 115           && ((a)->control == (priv)->pending_setup.control) \
 116           && ((a)->frame_fmt == (priv)->pending_setup.frame_fmt))
 117
 118 /* function prototypes */
 119 static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port);
 120 static void oti6858_close(struct usb_serial_port *port);
 121 static void oti6858_set_termios(struct tty_struct *tty,
 122                                 struct usb_serial_port *port,
 123                                 const struct ktermios *old_termios);
 124 static void oti6858_init_termios(struct tty_struct *tty);
 125 static void oti6858_read_int_callback(struct urb *urb);
 126 static void oti6858_read_bulk_callback(struct urb *urb);
 127 static void oti6858_write_bulk_callback(struct urb *urb);
 128 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
 129                         const unsigned char *buf, int count);
 130 static unsigned int oti6858_write_room(struct tty_struct *tty);
 131 static unsigned int oti6858_chars_in_buffer(struct tty_struct *tty);
 132 static int oti6858_tiocmget(struct tty_struct *tty);
 133 static int oti6858_tiocmset(struct tty_struct *tty,
 134                                 unsigned int set, unsigned int clear);
 135 static int oti6858_port_probe(struct usb_serial_port *port);
 136 static void oti6858_port_remove(struct usb_serial_port *port);
 137
 138 /* device info */
 139 static struct usb_serial_driver oti6858_device = {
 140         .driver = {
 141                 .name =         "oti6858",
 142         },
 143         .id_table =             id_table,
 144         .num_ports =            1,
 145         .num_bulk_in =          1,
 146         .num_bulk_out =         1,
 147         .num_interrupt_in =     1,
 148         .open =                 oti6858_open,
 149         .close =                oti6858_close,
 150         .write =                oti6858_write,
 151         .set_termios =          oti6858_set_termios,
 152         .init_termios =         oti6858_init_termios,
 153         .tiocmget =             oti6858_tiocmget,
 154         .tiocmset =             oti6858_tiocmset,
 155         .tiocmiwait =           usb_serial_generic_tiocmiwait,
 156         .read_bulk_callback =   oti6858_read_bulk_callback,
 157         .read_int_callback =    oti6858_read_int_callback,
 158         .write_bulk_callback =  oti6858_write_bulk_callback,
 159         .write_room =           oti6858_write_room,
 160         .chars_in_buffer =      oti6858_chars_in_buffer,
 161         .port_probe =           oti6858_port_probe,
 162         .port_remove =          oti6858_port_remove,
 163 };
 164
 165 static struct usb_serial_driver * const serial_drivers[] = {
 166         &oti6858_device, NULL
 167 };
 168
 169 struct oti6858_private {
 170         spinlock_t lock;
 171
 172         struct oti6858_control_pkt status;
 173
 174         struct {
 175                 u8 read_urb_in_use;
 176                 u8 write_urb_in_use;
 177         } flags;
 178         struct delayed_work delayed_write_work;
 179
 180         struct {
 181                 __le16 divisor;
 182                 u8 frame_fmt;
 183                 u8 control;
 184         } pending_setup;
 185         u8 transient;
 186         u8 setup_done;
 187         struct delayed_work delayed_setup_work;
 188
 189         struct usb_serial_port *port;   /* USB port with which associated */
 190 };
 191
 192 static void setup_line(struct work_struct *work)
 193 {
 194         struct oti6858_private *priv = container_of(work,
 195                         struct oti6858_private, delayed_setup_work.work);
 196         struct usb_serial_port *port = priv->port;
 197         struct oti6858_control_pkt *new_setup;
 198         unsigned long flags;
 199         int result;
 200
 201         new_setup = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
 202         if (!new_setup) {
 203                 /* we will try again */
 204                 schedule_delayed_work(&priv->delayed_setup_work,
 205                                                 msecs_to_jiffies(2));
 206                 return;
 207         }
 208
 209         result = usb_control_msg(port->serial->dev,
 210                                 usb_rcvctrlpipe(port->serial->dev, 0),
 211                                 OTI6858_REQ_T_GET_STATUS,
 212                                 OTI6858_REQ_GET_STATUS,
 213                                 0, 0,
 214                                 new_setup, OTI6858_CTRL_PKT_SIZE,
 215                                 100);
 216
 217         if (result != OTI6858_CTRL_PKT_SIZE) {
 218                 dev_err(&port->dev, "%s(): error reading status\n", __func__);
 219                 kfree(new_setup);
 220                 /* we will try again */
 221                 schedule_delayed_work(&priv->delayed_setup_work,
 222                                                         msecs_to_jiffies(2));
 223                 return;
 224         }
 225
 226         spin_lock_irqsave(&priv->lock, flags);
 227         if (!OTI6858_CTRL_EQUALS_PENDING(new_setup, priv)) {
 228                 new_setup->divisor = priv->pending_setup.divisor;
 229                 new_setup->control = priv->pending_setup.control;
 230                 new_setup->frame_fmt = priv->pending_setup.frame_fmt;
 231
 232                 spin_unlock_irqrestore(&priv->lock, flags);
 233                 result = usb_control_msg(port->serial->dev,
 234                                         usb_sndctrlpipe(port->serial->dev, 0),
 235                                         OTI6858_REQ_T_SET_LINE,
 236                                         OTI6858_REQ_SET_LINE,
 237                                         0, 0,
 238                                         new_setup, OTI6858_CTRL_PKT_SIZE,
 239                                         100);
 240         } else {
 241                 spin_unlock_irqrestore(&priv->lock, flags);
 242                 result = 0;
 243         }
 244         kfree(new_setup);
 245
 246         spin_lock_irqsave(&priv->lock, flags);
 247         if (result != OTI6858_CTRL_PKT_SIZE)
 248                 priv->transient = 0;
 249         priv->setup_done = 1;
 250         spin_unlock_irqrestore(&priv->lock, flags);
 251
 252         dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
 253         result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 254         if (result != 0) {
 255                 dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
 256                         __func__, result);
 257         }
 258 }
 259
 260 static void send_data(struct work_struct *work)
 261 {
 262         struct oti6858_private *priv = container_of(work,
 263                         struct oti6858_private, delayed_write_work.work);
 264         struct usb_serial_port *port = priv->port;
 265         int count = 0, result;
 266         unsigned long flags;
 267         u8 *allow;
 268
 269         spin_lock_irqsave(&priv->lock, flags);
 270         if (priv->flags.write_urb_in_use) {
 271                 spin_unlock_irqrestore(&priv->lock, flags);
 272                 schedule_delayed_work(&priv->delayed_write_work,
 273                                                 msecs_to_jiffies(2));
 274                 return;
 275         }
 276         priv->flags.write_urb_in_use = 1;
 277         spin_unlock_irqrestore(&priv->lock, flags);
 278
 279         spin_lock_irqsave(&port->lock, flags);
 280         count = kfifo_len(&port->write_fifo);
 281         spin_unlock_irqrestore(&port->lock, flags);
 282
 283         if (count > port->bulk_out_size)
 284                 count = port->bulk_out_size;
 285
 286         if (count != 0) {
 287                 allow = kmalloc(1, GFP_KERNEL);
 288                 if (!allow)
 289                         return;
 290
 291                 result = usb_control_msg(port->serial->dev,
 292                                 usb_rcvctrlpipe(port->serial->dev, 0),
 293                                 OTI6858_REQ_T_CHECK_TXBUFF,
 294                                 OTI6858_REQ_CHECK_TXBUFF,
 295                                 count, 0, allow, 1, 100);
 296                 if (result != 1 || *allow != 0)
 297                         count = 0;
 298                 kfree(allow);
 299         }
 300
 301         if (count == 0) {
 302                 priv->flags.write_urb_in_use = 0;
 303
 304                 dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
 305                 result = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
 306                 if (result != 0) {
 307                         dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
 308                                 __func__, result);
 309                 }
 310                 return;
 311         }
 312
 313         count = kfifo_out_locked(&port->write_fifo,
 314                                         port->write_urb->transfer_buffer,
 315                                         count, &port->lock);
 316         port->write_urb->transfer_buffer_length = count;
 317         result = usb_submit_urb(port->write_urb, GFP_NOIO);
 318         if (result != 0) {
 319                 dev_err_console(port, "%s(): usb_submit_urb() failed with error %d\n",
 320                                 __func__, result);
 321                 priv->flags.write_urb_in_use = 0;
 322         }
 323
 324         usb_serial_port_softint(port);
 325 }
 326
 327 static int oti6858_port_probe(struct usb_serial_port *port)
 328 {
 329         struct oti6858_private *priv;
 330
 331         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 332         if (!priv)
 333                 return -ENOMEM;
 334
 335         spin_lock_init(&priv->lock);
 336         priv->port = port;
 337         INIT_DELAYED_WORK(&priv->delayed_setup_work, setup_line);
 338         INIT_DELAYED_WORK(&priv->delayed_write_work, send_data);
 339
 340         usb_set_serial_port_data(port, priv);
 341
 342         port->port.drain_delay = 256;   /* FIXME: check the FIFO length */
 343
 344         return 0;
 345 }
 346
 347 static void oti6858_port_remove(struct usb_serial_port *port)
 348 {
 349         struct oti6858_private *priv;
 350
 351         priv = usb_get_serial_port_data(port);
 352         kfree(priv);
 353 }
 354
 355 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
 356                         const unsigned char *buf, int count)
 357 {
 358         if (!count)
 359                 return count;
 360
 361         count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
 362
 363         return count;
 364 }
 365
 366 static unsigned int oti6858_write_room(struct tty_struct *tty)
 367 {
 368         struct usb_serial_port *port = tty->driver_data;
 369         unsigned int room;
 370         unsigned long flags;
 371
 372         spin_lock_irqsave(&port->lock, flags);
 373         room = kfifo_avail(&port->write_fifo);
 374         spin_unlock_irqrestore(&port->lock, flags);
 375
 376         return room;
 377 }
 378
 379 static unsigned int oti6858_chars_in_buffer(struct tty_struct *tty)
 380 {
 381         struct usb_serial_port *port = tty->driver_data;
 382         unsigned int chars;
 383         unsigned long flags;
 384
 385         spin_lock_irqsave(&port->lock, flags);
 386         chars = kfifo_len(&port->write_fifo);
 387         spin_unlock_irqrestore(&port->lock, flags);
 388
 389         return chars;
 390 }
 391
 392 static void oti6858_init_termios(struct tty_struct *tty)
 393 {
 394         tty_encode_baud_rate(tty, 38400, 38400);
 395 }
 396
 397 static void oti6858_set_termios(struct tty_struct *tty,
 398                                 struct usb_serial_port *port,
 399                                 const struct ktermios *old_termios)
 400 {
 401         struct oti6858_private *priv = usb_get_serial_port_data(port);
 402         unsigned long flags;
 403         unsigned int cflag;
 404         u8 frame_fmt, control;
 405         __le16 divisor;
 406         int br;
 407
 408         cflag = tty->termios.c_cflag;
 409
 410         spin_lock_irqsave(&priv->lock, flags);
 411         frame_fmt = priv->pending_setup.frame_fmt;
 412         control = priv->pending_setup.control;
 413         spin_unlock_irqrestore(&priv->lock, flags);
 414
 415         frame_fmt &= ~FMT_DATA_BITS_MASK;
 416         switch (cflag & CSIZE) {
 417         case CS5:
 418                 frame_fmt |= FMT_DATA_BITS_5;
 419                 break;
 420         case CS6:
 421                 frame_fmt |= FMT_DATA_BITS_6;
 422                 break;
 423         case CS7:
 424                 frame_fmt |= FMT_DATA_BITS_7;
 425                 break;
 426         default:
 427         case CS8:
 428                 frame_fmt |= FMT_DATA_BITS_8;
 429                 break;
 430         }
 431
 432         /* manufacturer claims that this device can work with baud rates
 433          * up to 3 Mbps; I've tested it only on 115200 bps, so I can't
 434          * guarantee that any other baud rate will work (especially
 435          * the higher ones)
 436          */
 437         br = tty_get_baud_rate(tty);
 438         if (br == 0) {
 439                 divisor = 0;
 440         } else {
 441                 int real_br;
 442                 int new_divisor;
 443                 br = min(br, OTI6858_MAX_BAUD_RATE);
 444
 445                 new_divisor = (96000000 + 8 * br) / (16 * br);
 446                 real_br = 96000000 / (16 * new_divisor);
 447                 divisor = cpu_to_le16(new_divisor);
 448                 tty_encode_baud_rate(tty, real_br, real_br);
 449         }
 450
 451         frame_fmt &= ~FMT_STOP_BITS_MASK;
 452         if ((cflag & CSTOPB) != 0)
 453                 frame_fmt |= FMT_STOP_BITS_2;
 454         else
 455                 frame_fmt |= FMT_STOP_BITS_1;
 456
 457         frame_fmt &= ~FMT_PARITY_MASK;
 458         if ((cflag & PARENB) != 0) {
 459                 if ((cflag & PARODD) != 0)
 460                         frame_fmt |= FMT_PARITY_ODD;
 461                 else
 462                         frame_fmt |= FMT_PARITY_EVEN;
 463         } else {
 464                 frame_fmt |= FMT_PARITY_NONE;
 465         }
 466
 467         control &= ~CONTROL_MASK;
 468         if ((cflag & CRTSCTS) != 0)
 469                 control |= (CONTROL_DTR_HIGH | CONTROL_RTS_HIGH);
 470
 471         /* change control lines if we are switching to or from B0 */
 472         /* FIXME:
 473         spin_lock_irqsave(&priv->lock, flags);
 474         control = priv->line_control;
 475         if ((cflag & CBAUD) == B0)
 476                 priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
 477         else
 478                 priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
 479         if (control != priv->line_control) {
 480                 control = priv->line_control;
 481                 spin_unlock_irqrestore(&priv->lock, flags);
 482                 set_control_lines(serial->dev, control);
 483         } else {
 484                 spin_unlock_irqrestore(&priv->lock, flags);
 485         }
 486         */
 487
 488         spin_lock_irqsave(&priv->lock, flags);
 489         if (divisor != priv->pending_setup.divisor
 490                         || control != priv->pending_setup.control
 491                         || frame_fmt != priv->pending_setup.frame_fmt) {
 492                 priv->pending_setup.divisor = divisor;
 493                 priv->pending_setup.control = control;
 494                 priv->pending_setup.frame_fmt = frame_fmt;
 495         }
 496         spin_unlock_irqrestore(&priv->lock, flags);
 497 }
 498
 499 static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port)
 500 {
 501         struct oti6858_private *priv = usb_get_serial_port_data(port);
 502         struct usb_serial *serial = port->serial;
 503         struct oti6858_control_pkt *buf;
 504         unsigned long flags;
 505         int result;
 506
 507         usb_clear_halt(serial->dev, port->write_urb->pipe);
 508         usb_clear_halt(serial->dev, port->read_urb->pipe);
 509
 510         buf = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
 511         if (!buf)
 512                 return -ENOMEM;
 513
 514         result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
 515                                 OTI6858_REQ_T_GET_STATUS,
 516                                 OTI6858_REQ_GET_STATUS,
 517                                 0, 0,
 518                                 buf, OTI6858_CTRL_PKT_SIZE,
 519                                 100);
 520         if (result != OTI6858_CTRL_PKT_SIZE) {
 521                 /* assume default (after power-on reset) values */
 522                 buf->divisor = cpu_to_le16(0x009c);     /* 38400 bps */
 523                 buf->frame_fmt = 0x03;  /* 8N1 */
 524                 buf->something = 0x43;
 525                 buf->control = 0x4c;    /* DTR, RTS */
 526                 buf->tx_status = 0x00;
 527                 buf->pin_state = 0x5b;  /* RTS, CTS, DSR, DTR, RI, DCD */
 528                 buf->rx_bytes_avail = 0x00;
 529         }
 530
 531         spin_lock_irqsave(&priv->lock, flags);
 532         memcpy(&priv->status, buf, OTI6858_CTRL_PKT_SIZE);
 533         priv->pending_setup.divisor = buf->divisor;
 534         priv->pending_setup.frame_fmt = buf->frame_fmt;
 535         priv->pending_setup.control = buf->control;
 536         spin_unlock_irqrestore(&priv->lock, flags);
 537         kfree(buf);
 538
 539         dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
 540         result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 541         if (result != 0) {
 542                 dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
 543                         __func__, result);
 544                 oti6858_close(port);
 545                 return result;
 546         }
 547
 548         /* setup termios */
 549         if (tty)
 550                 oti6858_set_termios(tty, port, NULL);
 551
 552         return 0;
 553 }
 554
 555 static void oti6858_close(struct usb_serial_port *port)
 556 {
 557         struct oti6858_private *priv = usb_get_serial_port_data(port);
 558         unsigned long flags;
 559
 560         spin_lock_irqsave(&port->lock, flags);
 561         /* clear out any remaining data in the buffer */
 562         kfifo_reset_out(&port->write_fifo);
 563         spin_unlock_irqrestore(&port->lock, flags);
 564
 565         dev_dbg(&port->dev, "%s(): after buf_clear()\n", __func__);
 566
 567         /* cancel scheduled setup */
 568         cancel_delayed_work_sync(&priv->delayed_setup_work);
 569         cancel_delayed_work_sync(&priv->delayed_write_work);
 570
 571         /* shutdown our urbs */
 572         dev_dbg(&port->dev, "%s(): shutting down urbs\n", __func__);
 573         usb_kill_urb(port->write_urb);
 574         usb_kill_urb(port->read_urb);
 575         usb_kill_urb(port->interrupt_in_urb);
 576 }
 577
 578 static int oti6858_tiocmset(struct tty_struct *tty,
 579                                 unsigned int set, unsigned int clear)
 580 {
 581         struct usb_serial_port *port = tty->driver_data;
 582         struct oti6858_private *priv = usb_get_serial_port_data(port);
 583         unsigned long flags;
 584         u8 control;
 585
 586         dev_dbg(&port->dev, "%s(set = 0x%08x, clear = 0x%08x)\n",
 587                 __func__, set, clear);
 588
 589         /* FIXME: check if this is correct (active high/low) */
 590         spin_lock_irqsave(&priv->lock, flags);
 591         control = priv->pending_setup.control;
 592         if ((set & TIOCM_RTS) != 0)
 593                 control |= CONTROL_RTS_HIGH;
 594         if ((set & TIOCM_DTR) != 0)
 595                 control |= CONTROL_DTR_HIGH;
 596         if ((clear & TIOCM_RTS) != 0)
 597                 control &= ~CONTROL_RTS_HIGH;
 598         if ((clear & TIOCM_DTR) != 0)
 599                 control &= ~CONTROL_DTR_HIGH;
 600
 601         if (control != priv->pending_setup.control)
 602                 priv->pending_setup.control = control;
 603
 604         spin_unlock_irqrestore(&priv->lock, flags);
 605         return 0;
 606 }
 607
 608 static int oti6858_tiocmget(struct tty_struct *tty)
 609 {
 610         struct usb_serial_port *port = tty->driver_data;
 611         struct oti6858_private *priv = usb_get_serial_port_data(port);
 612         unsigned long flags;
 613         unsigned pin_state;
 614         unsigned result = 0;
 615
 616         spin_lock_irqsave(&priv->lock, flags);
 617         pin_state = priv->status.pin_state & PIN_MASK;
 618         spin_unlock_irqrestore(&priv->lock, flags);
 619
 620         /* FIXME: check if this is correct (active high/low) */
 621         if ((pin_state & PIN_RTS) != 0)
 622                 result |= TIOCM_RTS;
 623         if ((pin_state & PIN_CTS) != 0)
 624                 result |= TIOCM_CTS;
 625         if ((pin_state & PIN_DSR) != 0)
 626                 result |= TIOCM_DSR;
 627         if ((pin_state & PIN_DTR) != 0)
 628                 result |= TIOCM_DTR;
 629         if ((pin_state & PIN_RI) != 0)
 630                 result |= TIOCM_RI;
 631         if ((pin_state & PIN_DCD) != 0)
 632                 result |= TIOCM_CD;
 633
 634         dev_dbg(&port->dev, "%s() = 0x%08x\n", __func__, result);
 635
 636         return result;
 637 }
 638
 639 static void oti6858_read_int_callback(struct urb *urb)
 640 {
 641         struct usb_serial_port *port =  urb->context;
 642         struct oti6858_private *priv = usb_get_serial_port_data(port);
 643         int transient = 0, can_recv = 0, resubmit = 1;
 644         int status = urb->status;
 645
 646         switch (status) {
 647         case 0:
 648                 /* success */
 649                 break;
 650         case -ECONNRESET:
 651         case -ENOENT:
 652         case -ESHUTDOWN:
 653                 /* this urb is terminated, clean up */
 654                 dev_dbg(&urb->dev->dev, "%s(): urb shutting down with status: %d\n",
 655                         __func__, status);
 656                 return;
 657         default:
 658                 dev_dbg(&urb->dev->dev, "%s(): nonzero urb status received: %d\n",
 659                         __func__, status);
 660                 break;
 661         }
 662
 663         if (status == 0 && urb->actual_length == OTI6858_CTRL_PKT_SIZE) {
 664                 struct oti6858_control_pkt *xs = urb->transfer_buffer;
 665                 unsigned long flags;
 666
 667                 spin_lock_irqsave(&priv->lock, flags);
 668
 669                 if (!priv->transient) {
 670                         if (!OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
 671                                 if (xs->rx_bytes_avail == 0) {
 672                                         priv->transient = 4;
 673                                         priv->setup_done = 0;
 674                                         resubmit = 0;
 675                                         dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
 676                                         schedule_delayed_work(&priv->delayed_setup_work, 0);
 677                                 }
 678                         }
 679                 } else {
 680                         if (OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
 681                                 priv->transient = 0;
 682                         } else if (!priv->setup_done) {
 683                                 resubmit = 0;
 684                         } else if (--priv->transient == 0) {
 685                                 if (xs->rx_bytes_avail == 0) {
 686                                         priv->transient = 4;
 687                                         priv->setup_done = 0;
 688                                         resubmit = 0;
 689                                         dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
 690                                         schedule_delayed_work(&priv->delayed_setup_work, 0);
 691                                 }
 692                         }
 693                 }
 694
 695                 if (!priv->transient) {
 696                         u8 delta = xs->pin_state ^ priv->status.pin_state;
 697
 698                         if (delta & PIN_MSR_MASK) {
 699                                 if (delta & PIN_CTS)
 700                                         port->icount.cts++;
 701                                 if (delta & PIN_DSR)
 702                                         port->icount.dsr++;
 703                                 if (delta & PIN_RI)
 704                                         port->icount.rng++;
 705                                 if (delta & PIN_DCD)
 706                                         port->icount.dcd++;
 707
 708                                 wake_up_interruptible(&port->port.delta_msr_wait);
 709                         }
 710
 711                         memcpy(&priv->status, xs, OTI6858_CTRL_PKT_SIZE);
 712                 }
 713
 714                 if (!priv->transient && xs->rx_bytes_avail != 0) {
 715                         can_recv = xs->rx_bytes_avail;
 716                         priv->flags.read_urb_in_use = 1;
 717                 }
 718
 719                 transient = priv->transient;
 720                 spin_unlock_irqrestore(&priv->lock, flags);
 721         }
 722
 723         if (can_recv) {
 724                 int result;
 725
 726                 result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
 727                 if (result != 0) {
 728                         priv->flags.read_urb_in_use = 0;
 729                         dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
 730                                         " error %d\n", __func__, result);
 731                 } else {
 732                         resubmit = 0;
 733                 }
 734         } else if (!transient) {
 735                 unsigned long flags;
 736                 int count;
 737
 738                 spin_lock_irqsave(&port->lock, flags);
 739                 count = kfifo_len(&port->write_fifo);
 740                 spin_unlock_irqrestore(&port->lock, flags);
 741
 742                 spin_lock_irqsave(&priv->lock, flags);
 743                 if (priv->flags.write_urb_in_use == 0 && count != 0) {
 744                         schedule_delayed_work(&priv->delayed_write_work, 0);
 745                         resubmit = 0;
 746                 }
 747                 spin_unlock_irqrestore(&priv->lock, flags);
 748         }
 749
 750         if (resubmit) {
 751                 int result;
 752
 753 /*              dev_dbg(&urb->dev->dev, "%s(): submitting interrupt urb\n", __func__); */
 754                 result = usb_submit_urb(urb, GFP_ATOMIC);
 755                 if (result != 0) {
 756                         dev_err(&urb->dev->dev,
 757                                         "%s(): usb_submit_urb() failed with"
 758                                         " error %d\n", __func__, result);
 759                 }
 760         }
 761 }
 762
 763 static void oti6858_read_bulk_callback(struct urb *urb)
 764 {
 765         struct usb_serial_port *port =  urb->context;
 766         struct oti6858_private *priv = usb_get_serial_port_data(port);
 767         unsigned char *data = urb->transfer_buffer;
 768         unsigned long flags;
 769         int status = urb->status;
 770         int result;
 771
 772         spin_lock_irqsave(&priv->lock, flags);
 773         priv->flags.read_urb_in_use = 0;
 774         spin_unlock_irqrestore(&priv->lock, flags);
 775
 776         if (status != 0) {
 777                 dev_dbg(&urb->dev->dev, "%s(): unable to handle the error, exiting\n", __func__);
 778                 return;
 779         }
 780
 781         if (urb->actual_length > 0) {
 782                 tty_insert_flip_string(&port->port, data, urb->actual_length);
 783                 tty_flip_buffer_push(&port->port);
 784         }
 785
 786         /* schedule the interrupt urb */
 787         result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
 788         if (result != 0 && result != -EPERM) {
 789                 dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
 790                                 " error %d\n", __func__, result);
 791         }
 792 }
 793
 794 static void oti6858_write_bulk_callback(struct urb *urb)
 795 {
 796         struct usb_serial_port *port =  urb->context;
 797         struct oti6858_private *priv = usb_get_serial_port_data(port);
 798         int status = urb->status;
 799         int result;
 800
 801         switch (status) {
 802         case 0:
 803                 /* success */
 804                 break;
 805         case -ECONNRESET:
 806         case -ENOENT:
 807         case -ESHUTDOWN:
 808                 /* this urb is terminated, clean up */
 809                 dev_dbg(&urb->dev->dev, "%s(): urb shutting down with status: %d\n", __func__, status);
 810                 priv->flags.write_urb_in_use = 0;
 811                 return;
 812         default:
 813                 /* error in the urb, so we have to resubmit it */
 814                 dev_dbg(&urb->dev->dev, "%s(): nonzero write bulk status received: %d\n", __func__, status);
 815                 dev_dbg(&urb->dev->dev, "%s(): overflow in write\n", __func__);
 816
 817                 port->write_urb->transfer_buffer_length = 1;
 818                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
 819                 if (result) {
 820                         dev_err_console(port, "%s(): usb_submit_urb() failed,"
 821                                         " error %d\n", __func__, result);
 822                 } else {
 823                         return;
 824                 }
 825         }
 826
 827         priv->flags.write_urb_in_use = 0;
 828
 829         /* schedule the interrupt urb if we are still open */
 830         dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
 831         result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
 832         if (result != 0) {
 833                 dev_err(&port->dev, "%s(): failed submitting int urb,"
 834                                         " error %d\n", __func__, result);
 835         }
 836 }
 837
 838 module_usb_serial_driver(serial_drivers, id_table);
 839
 840 MODULE_DESCRIPTION(OTI6858_DESCRIPTION);
 841 MODULE_AUTHOR(OTI6858_AUTHOR);
 842 MODULE_LICENSE("GPL v2");