drivers/serial/jsm/jsm_tty.c

   1 /************************************************************************
   2  * Copyright 2003 Digi International (www.digi.com)
   3  *
   4  * Copyright (C) 2004 IBM Corporation. All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2, or (at your option)
   9  * any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED; without even the
  13  * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  14  * PURPOSE.  See the GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 * Temple Place - Suite 330, Boston,
  19  * MA  02111-1307, USA.
  20  *
  21  * Contact Information:
  22  * Scott H Kilau <Scott_Kilau@digi.com>
  23  * Ananda Venkatarman <mansarov@us.ibm.com>
  24  * Modifications:
  25  * 01/19/06:    changed jsm_input routine to use the dynamically allocated
  26  *              tty_buffer changes. Contributors: Scott Kilau and Ananda V.
  27  ***********************************************************************/
  28 #include <linux/tty.h>
  29 #include <linux/tty_flip.h>
  30 #include <linux/serial_reg.h>
  31 #include <linux/delay.h>        /* For udelay */
  32 #include <linux/pci.h>
  33
  34 #include "jsm.h"
  35
  36 static void jsm_carrier(struct jsm_channel *ch);
  37
  38 static inline int jsm_get_mstat(struct jsm_channel *ch)
  39 {
  40         unsigned char mstat;
  41         unsigned result;
  42
  43         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "start\n");
  44
  45         mstat = (ch->ch_mostat | ch->ch_mistat);
  46
  47         result = 0;
  48
  49         if (mstat & UART_MCR_DTR)
  50                 result |= TIOCM_DTR;
  51         if (mstat & UART_MCR_RTS)
  52                 result |= TIOCM_RTS;
  53         if (mstat & UART_MSR_CTS)
  54                 result |= TIOCM_CTS;
  55         if (mstat & UART_MSR_DSR)
  56                 result |= TIOCM_DSR;
  57         if (mstat & UART_MSR_RI)
  58                 result |= TIOCM_RI;
  59         if (mstat & UART_MSR_DCD)
  60                 result |= TIOCM_CD;
  61
  62         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "finish\n");
  63         return result;
  64 }
  65
  66 static unsigned int jsm_tty_tx_empty(struct uart_port *port)
  67 {
  68         return TIOCSER_TEMT;
  69 }
  70
  71 /*
  72  * Return modem signals to ld.
  73  */
  74 static unsigned int jsm_tty_get_mctrl(struct uart_port *port)
  75 {
  76         int result;
  77         struct jsm_channel *channel = (struct jsm_channel *)port;
  78
  79         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
  80
  81         result = jsm_get_mstat(channel);
  82
  83         if (result < 0)
  84                 return -ENXIO;
  85
  86         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
  87
  88         return result;
  89 }
  90
  91 /*
  92  * jsm_set_modem_info()
  93  *
  94  * Set modem signals, called by ld.
  95  */
  96 static void jsm_tty_set_mctrl(struct uart_port *port, unsigned int mctrl)
  97 {
  98         struct jsm_channel *channel = (struct jsm_channel *)port;
  99
 100         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
 101
 102         if (mctrl & TIOCM_RTS)
 103                 channel->ch_mostat |= UART_MCR_RTS;
 104         else
 105                 channel->ch_mostat &= ~UART_MCR_RTS;
 106
 107         if (mctrl & TIOCM_DTR)
 108                 channel->ch_mostat |= UART_MCR_DTR;
 109         else
 110                 channel->ch_mostat &= ~UART_MCR_DTR;
 111
 112         channel->ch_bd->bd_ops->assert_modem_signals(channel);
 113
 114         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
 115         udelay(10);
 116 }
 117
 118 static void jsm_tty_start_tx(struct uart_port *port)
 119 {
 120         struct jsm_channel *channel = (struct jsm_channel *)port;
 121
 122         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
 123
 124         channel->ch_flags &= ~(CH_STOP);
 125         jsm_tty_write(port);
 126
 127         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
 128 }
 129
 130 static void jsm_tty_stop_tx(struct uart_port *port)
 131 {
 132         struct jsm_channel *channel = (struct jsm_channel *)port;
 133
 134         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
 135
 136         channel->ch_flags |= (CH_STOP);
 137
 138         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
 139 }
 140
 141 static void jsm_tty_send_xchar(struct uart_port *port, char ch)
 142 {
 143         unsigned long lock_flags;
 144         struct jsm_channel *channel = (struct jsm_channel *)port;
 145         struct ktermios *termios;
 146
 147         spin_lock_irqsave(&port->lock, lock_flags);
 148         termios = port->info->port.tty->termios;
 149         if (ch == termios->c_cc[VSTART])
 150                 channel->ch_bd->bd_ops->send_start_character(channel);
 151
 152         if (ch == termios->c_cc[VSTOP])
 153                 channel->ch_bd->bd_ops->send_stop_character(channel);
 154         spin_unlock_irqrestore(&port->lock, lock_flags);
 155 }
 156
 157 static void jsm_tty_stop_rx(struct uart_port *port)
 158 {
 159         struct jsm_channel *channel = (struct jsm_channel *)port;
 160
 161         channel->ch_bd->bd_ops->disable_receiver(channel);
 162 }
 163
 164 static void jsm_tty_enable_ms(struct uart_port *port)
 165 {
 166         /* Nothing needed */
 167 }
 168
 169 static void jsm_tty_break(struct uart_port *port, int break_state)
 170 {
 171         unsigned long lock_flags;
 172         struct jsm_channel *channel = (struct jsm_channel *)port;
 173
 174         spin_lock_irqsave(&port->lock, lock_flags);
 175         if (break_state == -1)
 176                 channel->ch_bd->bd_ops->send_break(channel);
 177         else
 178                 channel->ch_bd->bd_ops->clear_break(channel, 0);
 179
 180         spin_unlock_irqrestore(&port->lock, lock_flags);
 181 }
 182
 183 static int jsm_tty_open(struct uart_port *port)
 184 {
 185         struct jsm_board *brd;
 186         struct jsm_channel *channel = (struct jsm_channel *)port;
 187         struct ktermios *termios;
 188
 189         /* Get board pointer from our array of majors we have allocated */
 190         brd = channel->ch_bd;
 191
 192         /*
 193          * Allocate channel buffers for read/write/error.
 194          * Set flag, so we don't get trounced on.
 195          */
 196         channel->ch_flags |= (CH_OPENING);
 197
 198         /* Drop locks, as malloc with GFP_KERNEL can sleep */
 199
 200         if (!channel->ch_rqueue) {
 201                 channel->ch_rqueue = kzalloc(RQUEUESIZE, GFP_KERNEL);
 202                 if (!channel->ch_rqueue) {
 203                         jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
 204                                 "unable to allocate read queue buf");
 205                         return -ENOMEM;
 206                 }
 207         }
 208         if (!channel->ch_equeue) {
 209                 channel->ch_equeue = kzalloc(EQUEUESIZE, GFP_KERNEL);
 210                 if (!channel->ch_equeue) {
 211                         jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
 212                                 "unable to allocate error queue buf");
 213                         return -ENOMEM;
 214                 }
 215         }
 216         if (!channel->ch_wqueue) {
 217                 channel->ch_wqueue = kzalloc(WQUEUESIZE, GFP_KERNEL);
 218                 if (!channel->ch_wqueue) {
 219                         jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
 220                                 "unable to allocate write queue buf");
 221                         return -ENOMEM;
 222                 }
 223         }
 224
 225         channel->ch_flags &= ~(CH_OPENING);
 226         /*
 227          * Initialize if neither terminal is open.
 228          */
 229         jsm_printk(OPEN, INFO, &channel->ch_bd->pci_dev,
 230                 "jsm_open: initializing channel in open...\n");
 231
 232         /*
 233          * Flush input queues.
 234          */
 235         channel->ch_r_head = channel->ch_r_tail = 0;
 236         channel->ch_e_head = channel->ch_e_tail = 0;
 237         channel->ch_w_head = channel->ch_w_tail = 0;
 238
 239         brd->bd_ops->flush_uart_write(channel);
 240         brd->bd_ops->flush_uart_read(channel);
 241
 242         channel->ch_flags = 0;
 243         channel->ch_cached_lsr = 0;
 244         channel->ch_stops_sent = 0;
 245
 246         termios = port->info->port.tty->termios;
 247         channel->ch_c_cflag     = termios->c_cflag;
 248         channel->ch_c_iflag     = termios->c_iflag;
 249         channel->ch_c_oflag     = termios->c_oflag;
 250         channel->ch_c_lflag     = termios->c_lflag;
 251         channel->ch_startc      = termios->c_cc[VSTART];
 252         channel->ch_stopc       = termios->c_cc[VSTOP];
 253
 254         /* Tell UART to init itself */
 255         brd->bd_ops->uart_init(channel);
 256
 257         /*
 258          * Run param in case we changed anything
 259          */
 260         brd->bd_ops->param(channel);
 261
 262         jsm_carrier(channel);
 263
 264         channel->ch_open_count++;
 265
 266         jsm_printk(OPEN, INFO, &channel->ch_bd->pci_dev, "finish\n");
 267         return 0;
 268 }
 269
 270 static void jsm_tty_close(struct uart_port *port)
 271 {
 272         struct jsm_board *bd;
 273         struct ktermios *ts;
 274         struct jsm_channel *channel = (struct jsm_channel *)port;
 275
 276         jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev, "start\n");
 277
 278         bd = channel->ch_bd;
 279         ts = port->info->port.tty->termios;
 280
 281         channel->ch_flags &= ~(CH_STOPI);
 282
 283         channel->ch_open_count--;
 284
 285         /*
 286          * If we have HUPCL set, lower DTR and RTS
 287          */
 288         if (channel->ch_c_cflag & HUPCL) {
 289                 jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev,
 290                         "Close. HUPCL set, dropping DTR/RTS\n");
 291
 292                 /* Drop RTS/DTR */
 293                 channel->ch_mostat &= ~(UART_MCR_DTR | UART_MCR_RTS);
 294                 bd->bd_ops->assert_modem_signals(channel);
 295         }
 296
 297         channel->ch_old_baud = 0;
 298
 299         /* Turn off UART interrupts for this port */
 300         channel->ch_bd->bd_ops->uart_off(channel);
 301
 302         jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev, "finish\n");
 303 }
 304
 305 static void jsm_tty_set_termios(struct uart_port *port,
 306                                  struct ktermios *termios,
 307                                  struct ktermios *old_termios)
 308 {
 309         unsigned long lock_flags;
 310         struct jsm_channel *channel = (struct jsm_channel *)port;
 311
 312         spin_lock_irqsave(&port->lock, lock_flags);
 313         channel->ch_c_cflag     = termios->c_cflag;
 314         channel->ch_c_iflag     = termios->c_iflag;
 315         channel->ch_c_oflag     = termios->c_oflag;
 316         channel->ch_c_lflag     = termios->c_lflag;
 317         channel->ch_startc      = termios->c_cc[VSTART];
 318         channel->ch_stopc       = termios->c_cc[VSTOP];
 319
 320         channel->ch_bd->bd_ops->param(channel);
 321         jsm_carrier(channel);
 322         spin_unlock_irqrestore(&port->lock, lock_flags);
 323 }
 324
 325 static const char *jsm_tty_type(struct uart_port *port)
 326 {
 327         return "jsm";
 328 }
 329
 330 static void jsm_tty_release_port(struct uart_port *port)
 331 {
 332 }
 333
 334 static int jsm_tty_request_port(struct uart_port *port)
 335 {
 336         return 0;
 337 }
 338
 339 static void jsm_config_port(struct uart_port *port, int flags)
 340 {
 341         port->type = PORT_JSM;
 342 }
 343
 344 static struct uart_ops jsm_ops = {
 345         .tx_empty       = jsm_tty_tx_empty,
 346         .set_mctrl      = jsm_tty_set_mctrl,
 347         .get_mctrl      = jsm_tty_get_mctrl,
 348         .stop_tx        = jsm_tty_stop_tx,
 349         .start_tx       = jsm_tty_start_tx,
 350         .send_xchar     = jsm_tty_send_xchar,
 351         .stop_rx        = jsm_tty_stop_rx,
 352         .enable_ms      = jsm_tty_enable_ms,
 353         .break_ctl      = jsm_tty_break,
 354         .startup        = jsm_tty_open,
 355         .shutdown       = jsm_tty_close,
 356         .set_termios    = jsm_tty_set_termios,
 357         .type           = jsm_tty_type,
 358         .release_port   = jsm_tty_release_port,
 359         .request_port   = jsm_tty_request_port,
 360         .config_port    = jsm_config_port,
 361 };
 362
 363 /*
 364  * jsm_tty_init()
 365  *
 366  * Init the tty subsystem.  Called once per board after board has been
 367  * downloaded and init'ed.
 368  */
 369 int __devinit jsm_tty_init(struct jsm_board *brd)
 370 {
 371         int i;
 372         void __iomem *vaddr;
 373         struct jsm_channel *ch;
 374
 375         if (!brd)
 376                 return -ENXIO;
 377
 378         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 379
 380         /*
 381          * Initialize board structure elements.
 382          */
 383
 384         brd->nasync = brd->maxports;
 385
 386         /*
 387          * Allocate channel memory that might not have been allocated
 388          * when the driver was first loaded.
 389          */
 390         for (i = 0; i < brd->nasync; i++) {
 391                 if (!brd->channels[i]) {
 392
 393                         /*
 394                          * Okay to malloc with GFP_KERNEL, we are not at
 395                          * interrupt context, and there are no locks held.
 396                          */
 397                         brd->channels[i] = kzalloc(sizeof(struct jsm_channel), GFP_KERNEL);
 398                         if (!brd->channels[i]) {
 399                                 jsm_printk(CORE, ERR, &brd->pci_dev,
 400                                         "%s:%d Unable to allocate memory for channel struct\n",
 401                                                          __FILE__, __LINE__);
 402                         }
 403                 }
 404         }
 405
 406         ch = brd->channels[0];
 407         vaddr = brd->re_map_membase;
 408
 409         /* Set up channel variables */
 410         for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
 411
 412                 if (!brd->channels[i])
 413                         continue;
 414
 415                 spin_lock_init(&ch->ch_lock);
 416
 417                 if (brd->bd_uart_offset == 0x200)
 418                         ch->ch_neo_uart =  vaddr + (brd->bd_uart_offset * i);
 419
 420                 ch->ch_bd = brd;
 421                 ch->ch_portnum = i;
 422
 423                 /* .25 second delay */
 424                 ch->ch_close_delay = 250;
 425
 426                 init_waitqueue_head(&ch->ch_flags_wait);
 427         }
 428
 429         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 430         return 0;
 431 }
 432
 433 int __devinit jsm_uart_port_init(struct jsm_board *brd)
 434 {
 435         int i;
 436         struct jsm_channel *ch;
 437
 438         if (!brd)
 439                 return -ENXIO;
 440
 441         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 442
 443         /*
 444          * Initialize board structure elements.
 445          */
 446
 447         brd->nasync = brd->maxports;
 448
 449         /* Set up channel variables */
 450         for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
 451
 452                 if (!brd->channels[i])
 453                         continue;
 454
 455                 brd->channels[i]->uart_port.irq = brd->irq;
 456                 brd->channels[i]->uart_port.uartclk = 14745600;
 457                 brd->channels[i]->uart_port.type = PORT_JSM;
 458                 brd->channels[i]->uart_port.iotype = UPIO_MEM;
 459                 brd->channels[i]->uart_port.membase = brd->re_map_membase;
 460                 brd->channels[i]->uart_port.fifosize = 16;
 461                 brd->channels[i]->uart_port.ops = &jsm_ops;
 462                 brd->channels[i]->uart_port.line = brd->channels[i]->ch_portnum + brd->boardnum * 2;
 463                 if (uart_add_one_port (&jsm_uart_driver, &brd->channels[i]->uart_port))
 464                         printk(KERN_INFO "Added device failed\n");
 465                 else
 466                         printk(KERN_INFO "Added device \n");
 467         }
 468
 469         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 470         return 0;
 471 }
 472
 473 int jsm_remove_uart_port(struct jsm_board *brd)
 474 {
 475         int i;
 476         struct jsm_channel *ch;
 477
 478         if (!brd)
 479                 return -ENXIO;
 480
 481         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 482
 483         /*
 484          * Initialize board structure elements.
 485          */
 486
 487         brd->nasync = brd->maxports;
 488
 489         /* Set up channel variables */
 490         for (i = 0; i < brd->nasync; i++) {
 491
 492                 if (!brd->channels[i])
 493                         continue;
 494
 495                 ch = brd->channels[i];
 496
 497                 uart_remove_one_port(&jsm_uart_driver, &brd->channels[i]->uart_port);
 498         }
 499
 500         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 501         return 0;
 502 }
 503
 504 void jsm_input(struct jsm_channel *ch)
 505 {
 506         struct jsm_board *bd;
 507         struct tty_struct *tp;
 508         u32 rmask;
 509         u16 head;
 510         u16 tail;
 511         int data_len;
 512         unsigned long lock_flags;
 513         int len = 0;
 514         int n = 0;
 515         int s = 0;
 516         int i = 0;
 517
 518         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n");
 519
 520         if (!ch)
 521                 return;
 522
 523         tp = ch->uart_port.info->port.tty;
 524
 525         bd = ch->ch_bd;
 526         if(!bd)
 527                 return;
 528
 529         spin_lock_irqsave(&ch->ch_lock, lock_flags);
 530
 531         /*
 532          *Figure the number of characters in the buffer.
 533          *Exit immediately if none.
 534          */
 535
 536         rmask = RQUEUEMASK;
 537
 538         head = ch->ch_r_head & rmask;
 539         tail = ch->ch_r_tail & rmask;
 540
 541         data_len = (head - tail) & rmask;
 542         if (data_len == 0) {
 543                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 544                 return;
 545         }
 546
 547         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n");
 548
 549         /*
 550          *If the device is not open, or CREAD is off, flush
 551          *input data and return immediately.
 552          */
 553         if (!tp ||
 554                 !(tp->termios->c_cflag & CREAD) ) {
 555
 556                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 557                         "input. dropping %d bytes on port %d...\n", data_len, ch->ch_portnum);
 558                 ch->ch_r_head = tail;
 559
 560                 /* Force queue flow control to be released, if needed */
 561                 jsm_check_queue_flow_control(ch);
 562
 563                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 564                 return;
 565         }
 566
 567         /*
 568          * If we are throttled, simply don't read any data.
 569          */
 570         if (ch->ch_flags & CH_STOPI) {
 571                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 572                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 573                         "Port %d throttled, not reading any data. head: %x tail: %x\n",
 574                         ch->ch_portnum, head, tail);
 575                 return;
 576         }
 577
 578         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start 2\n");
 579
 580         if (data_len <= 0) {
 581                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 582                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "jsm_input 1\n");
 583                 return;
 584         }
 585
 586         len = tty_buffer_request_room(tp, data_len);
 587         n = len;
 588
 589         /*
 590          * n now contains the most amount of data we can copy,
 591          * bounded either by the flip buffer size or the amount
 592          * of data the card actually has pending...
 593          */
 594         while (n) {
 595                 s = ((head >= tail) ? head : RQUEUESIZE) - tail;
 596                 s = min(s, n);
 597
 598                 if (s <= 0)
 599                         break;
 600
 601                         /*
 602                          * If conditions are such that ld needs to see all
 603                          * UART errors, we will have to walk each character
 604                          * and error byte and send them to the buffer one at
 605                          * a time.
 606                          */
 607
 608                 if (I_PARMRK(tp) || I_BRKINT(tp) || I_INPCK(tp)) {
 609                         for (i = 0; i < s; i++) {
 610                                 /*
 611                                  * Give the Linux ld the flags in the
 612                                  * format it likes.
 613                                  */
 614                                 if (*(ch->ch_equeue +tail +i) & UART_LSR_BI)
 615                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i),  TTY_BREAK);
 616                                 else if (*(ch->ch_equeue +tail +i) & UART_LSR_PE)
 617                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_PARITY);
 618                                 else if (*(ch->ch_equeue +tail +i) & UART_LSR_FE)
 619                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_FRAME);
 620                                 else
 621                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_NORMAL);
 622                         }
 623                 } else {
 624                         tty_insert_flip_string(tp, ch->ch_rqueue + tail, s) ;
 625                 }
 626                 tail += s;
 627                 n -= s;
 628                 /* Flip queue if needed */
 629                 tail &= rmask;
 630         }
 631
 632         ch->ch_r_tail = tail & rmask;
 633         ch->ch_e_tail = tail & rmask;
 634         jsm_check_queue_flow_control(ch);
 635         spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 636
 637         /* Tell the tty layer its okay to "eat" the data now */
 638         tty_flip_buffer_push(tp);
 639
 640         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "finish\n");
 641 }
 642
 643 static void jsm_carrier(struct jsm_channel *ch)
 644 {
 645         struct jsm_board *bd;
 646
 647         int virt_carrier = 0;
 648         int phys_carrier = 0;
 649
 650         jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev, "start\n");
 651         if (!ch)
 652                 return;
 653
 654         bd = ch->ch_bd;
 655
 656         if (!bd)
 657                 return;
 658
 659         if (ch->ch_mistat & UART_MSR_DCD) {
 660                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 661                         "mistat: %x D_CD: %x\n", ch->ch_mistat, ch->ch_mistat & UART_MSR_DCD);
 662                 phys_carrier = 1;
 663         }
 664
 665         if (ch->ch_c_cflag & CLOCAL)
 666                 virt_carrier = 1;
 667
 668         jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 669                 "DCD: physical: %d virt: %d\n", phys_carrier, virt_carrier);
 670
 671         /*
 672          * Test for a VIRTUAL carrier transition to HIGH.
 673          */
 674         if (((ch->ch_flags & CH_FCAR) == 0) && (virt_carrier == 1)) {
 675
 676                 /*
 677                  * When carrier rises, wake any threads waiting
 678                  * for carrier in the open routine.
 679                  */
 680
 681                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 682                         "carrier: virt DCD rose\n");
 683
 684                 if (waitqueue_active(&(ch->ch_flags_wait)))
 685                         wake_up_interruptible(&ch->ch_flags_wait);
 686         }
 687
 688         /*
 689          * Test for a PHYSICAL carrier transition to HIGH.
 690          */
 691         if (((ch->ch_flags & CH_CD) == 0) && (phys_carrier == 1)) {
 692
 693                 /*
 694                  * When carrier rises, wake any threads waiting
 695                  * for carrier in the open routine.
 696                  */
 697
 698                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 699                         "carrier: physical DCD rose\n");
 700
 701                 if (waitqueue_active(&(ch->ch_flags_wait)))
 702                         wake_up_interruptible(&ch->ch_flags_wait);
 703         }
 704
 705         /*
 706          *  Test for a PHYSICAL transition to low, so long as we aren't
 707          *  currently ignoring physical transitions (which is what "virtual
 708          *  carrier" indicates).
 709          *
 710          *  The transition of the virtual carrier to low really doesn't
 711          *  matter... it really only means "ignore carrier state", not
 712          *  "make pretend that carrier is there".
 713          */
 714         if ((virt_carrier == 0) && ((ch->ch_flags & CH_CD) != 0)
 715                         && (phys_carrier == 0)) {
 716                 /*
 717                  *      When carrier drops:
 718                  *
 719                  *      Drop carrier on all open units.
 720                  *
 721                  *      Flush queues, waking up any task waiting in the
 722                  *      line discipline.
 723                  *
 724                  *      Send a hangup to the control terminal.
 725                  *
 726                  *      Enable all select calls.
 727                  */
 728                 if (waitqueue_active(&(ch->ch_flags_wait)))
 729                         wake_up_interruptible(&ch->ch_flags_wait);
 730         }
 731
 732         /*
 733          *  Make sure that our cached values reflect the current reality.
 734          */
 735         if (virt_carrier == 1)
 736                 ch->ch_flags |= CH_FCAR;
 737         else
 738                 ch->ch_flags &= ~CH_FCAR;
 739
 740         if (phys_carrier == 1)
 741                 ch->ch_flags |= CH_CD;
 742         else
 743                 ch->ch_flags &= ~CH_CD;
 744 }
 745
 746
 747 void jsm_check_queue_flow_control(struct jsm_channel *ch)
 748 {
 749         struct board_ops *bd_ops = ch->ch_bd->bd_ops;
 750         int qleft;
 751
 752         /* Store how much space we have left in the queue */
 753         if ((qleft = ch->ch_r_tail - ch->ch_r_head - 1) < 0)
 754                 qleft += RQUEUEMASK + 1;
 755
 756         /*
 757          * Check to see if we should enforce flow control on our queue because
 758          * the ld (or user) isn't reading data out of our queue fast enuf.
 759          *
 760          * NOTE: This is done based on what the current flow control of the
 761          * port is set for.
 762          *
 763          * 1) HWFLOW (RTS) - Turn off the UART's Receive interrupt.
 764          *      This will cause the UART's FIFO to back up, and force
 765          *      the RTS signal to be dropped.
 766          * 2) SWFLOW (IXOFF) - Keep trying to send a stop character to
 767          *      the other side, in hopes it will stop sending data to us.
 768          * 3) NONE - Nothing we can do.  We will simply drop any extra data
 769          *      that gets sent into us when the queue fills up.
 770          */
 771         if (qleft < 256) {
 772                 /* HWFLOW */
 773                 if (ch->ch_c_cflag & CRTSCTS) {
 774                         if(!(ch->ch_flags & CH_RECEIVER_OFF)) {
 775                                 bd_ops->disable_receiver(ch);
 776                                 ch->ch_flags |= (CH_RECEIVER_OFF);
 777                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 778                                         "Internal queue hit hilevel mark (%d)! Turning off interrupts.\n",
 779                                         qleft);
 780                         }
 781                 }
 782                 /* SWFLOW */
 783                 else if (ch->ch_c_iflag & IXOFF) {
 784                         if (ch->ch_stops_sent <= MAX_STOPS_SENT) {
 785                                 bd_ops->send_stop_character(ch);
 786                                 ch->ch_stops_sent++;
 787                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 788                                         "Sending stop char! Times sent: %x\n", ch->ch_stops_sent);
 789                         }
 790                 }
 791         }
 792
 793         /*
 794          * Check to see if we should unenforce flow control because
 795          * ld (or user) finally read enuf data out of our queue.
 796          *
 797          * NOTE: This is done based on what the current flow control of the
 798          * port is set for.
 799          *
 800          * 1) HWFLOW (RTS) - Turn back on the UART's Receive interrupt.
 801          *      This will cause the UART's FIFO to raise RTS back up,
 802          *      which will allow the other side to start sending data again.
 803          * 2) SWFLOW (IXOFF) - Send a start character to
 804          *      the other side, so it will start sending data to us again.
 805          * 3) NONE - Do nothing. Since we didn't do anything to turn off the
 806          *      other side, we don't need to do anything now.
 807          */
 808         if (qleft > (RQUEUESIZE / 2)) {
 809                 /* HWFLOW */
 810                 if (ch->ch_c_cflag & CRTSCTS) {
 811                         if (ch->ch_flags & CH_RECEIVER_OFF) {
 812                                 bd_ops->enable_receiver(ch);
 813                                 ch->ch_flags &= ~(CH_RECEIVER_OFF);
 814                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 815                                         "Internal queue hit lowlevel mark (%d)! Turning on interrupts.\n",
 816                                         qleft);
 817                         }
 818                 }
 819                 /* SWFLOW */
 820                 else if (ch->ch_c_iflag & IXOFF && ch->ch_stops_sent) {
 821                         ch->ch_stops_sent = 0;
 822                         bd_ops->send_start_character(ch);
 823                         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "Sending start char!\n");
 824                 }
 825         }
 826 }
 827
 828 /*
 829  * jsm_tty_write()
 830  *
 831  * Take data from the user or kernel and send it out to the FEP.
 832  * In here exists all the Transparent Print magic as well.
 833  */
 834 int jsm_tty_write(struct uart_port *port)
 835 {
 836         int bufcount;
 837         int data_count = 0,data_count1 =0;
 838         u16 head;
 839         u16 tail;
 840         u16 tmask;
 841         u32 remain;
 842         int temp_tail = port->info->xmit.tail;
 843         struct jsm_channel *channel = (struct jsm_channel *)port;
 844
 845         tmask = WQUEUEMASK;
 846         head = (channel->ch_w_head) & tmask;
 847         tail = (channel->ch_w_tail) & tmask;
 848
 849         if ((bufcount = tail - head - 1) < 0)
 850                 bufcount += WQUEUESIZE;
 851
 852         bufcount = min(bufcount, 56);
 853         remain = WQUEUESIZE - head;
 854
 855         data_count = 0;
 856         if (bufcount >= remain) {
 857                 bufcount -= remain;
 858                 while ((port->info->xmit.head != temp_tail) &&
 859                 (data_count < remain)) {
 860                         channel->ch_wqueue[head++] =
 861                         port->info->xmit.buf[temp_tail];
 862
 863                         temp_tail++;
 864                         temp_tail &= (UART_XMIT_SIZE - 1);
 865                         data_count++;
 866                 }
 867                 if (data_count == remain) head = 0;
 868         }
 869
 870         data_count1 = 0;
 871         if (bufcount > 0) {
 872                 remain = bufcount;
 873                 while ((port->info->xmit.head != temp_tail) &&
 874                         (data_count1 < remain)) {
 875                         channel->ch_wqueue[head++] =
 876                                 port->info->xmit.buf[temp_tail];
 877
 878                         temp_tail++;
 879                         temp_tail &= (UART_XMIT_SIZE - 1);
 880                         data_count1++;
 881
 882                 }
 883         }
 884
 885         port->info->xmit.tail = temp_tail;
 886
 887         data_count += data_count1;
 888         if (data_count) {
 889                 head &= tmask;
 890                 channel->ch_w_head = head;
 891         }
 892
 893         if (data_count) {
 894                 channel->ch_bd->bd_ops->copy_data_from_queue_to_uart(channel);
 895         }
 896
 897         return data_count;
 898 }