git.oblomov.eu Git - linux-2.6/blob - 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 DECLARE_BITMAP(linemap, MAXLINES);
  37
  38 static void jsm_carrier(struct jsm_channel *ch);
  39
  40 static inline int jsm_get_mstat(struct jsm_channel *ch)
  41 {
  42         unsigned char mstat;
  43         unsigned result;
  44
  45         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "start\n");
  46
  47         mstat = (ch->ch_mostat | ch->ch_mistat);
  48
  49         result = 0;
  50
  51         if (mstat & UART_MCR_DTR)
  52                 result |= TIOCM_DTR;
  53         if (mstat & UART_MCR_RTS)
  54                 result |= TIOCM_RTS;
  55         if (mstat & UART_MSR_CTS)
  56                 result |= TIOCM_CTS;
  57         if (mstat & UART_MSR_DSR)
  58                 result |= TIOCM_DSR;
  59         if (mstat & UART_MSR_RI)
  60                 result |= TIOCM_RI;
  61         if (mstat & UART_MSR_DCD)
  62                 result |= TIOCM_CD;
  63
  64         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "finish\n");
  65         return result;
  66 }
  67
  68 static unsigned int jsm_tty_tx_empty(struct uart_port *port)
  69 {
  70         return TIOCSER_TEMT;
  71 }
  72
  73 /*
  74  * Return modem signals to ld.
  75  */
  76 static unsigned int jsm_tty_get_mctrl(struct uart_port *port)
  77 {
  78         int result;
  79         struct jsm_channel *channel = (struct jsm_channel *)port;
  80
  81         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
  82
  83         result = jsm_get_mstat(channel);
  84
  85         if (result < 0)
  86                 return -ENXIO;
  87
  88         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
  89
  90         return result;
  91 }
  92
  93 /*
  94  * jsm_set_modem_info()
  95  *
  96  * Set modem signals, called by ld.
  97  */
  98 static void jsm_tty_set_mctrl(struct uart_port *port, unsigned int mctrl)
  99 {
 100         struct jsm_channel *channel = (struct jsm_channel *)port;
 101
 102         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
 103
 104         if (mctrl & TIOCM_RTS)
 105                 channel->ch_mostat |= UART_MCR_RTS;
 106         else
 107                 channel->ch_mostat &= ~UART_MCR_RTS;
 108
 109         if (mctrl & TIOCM_DTR)
 110                 channel->ch_mostat |= UART_MCR_DTR;
 111         else
 112                 channel->ch_mostat &= ~UART_MCR_DTR;
 113
 114         channel->ch_bd->bd_ops->assert_modem_signals(channel);
 115
 116         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
 117         udelay(10);
 118 }
 119
 120 static void jsm_tty_start_tx(struct uart_port *port)
 121 {
 122         struct jsm_channel *channel = (struct jsm_channel *)port;
 123
 124         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
 125
 126         channel->ch_flags &= ~(CH_STOP);
 127         jsm_tty_write(port);
 128
 129         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
 130 }
 131
 132 static void jsm_tty_stop_tx(struct uart_port *port)
 133 {
 134         struct jsm_channel *channel = (struct jsm_channel *)port;
 135
 136         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
 137
 138         channel->ch_flags |= (CH_STOP);
 139
 140         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
 141 }
 142
 143 static void jsm_tty_send_xchar(struct uart_port *port, char ch)
 144 {
 145         unsigned long lock_flags;
 146         struct jsm_channel *channel = (struct jsm_channel *)port;
 147         struct ktermios *termios;
 148
 149         spin_lock_irqsave(&port->lock, lock_flags);
 150         termios = port->info->port.tty->termios;
 151         if (ch == termios->c_cc[VSTART])
 152                 channel->ch_bd->bd_ops->send_start_character(channel);
 153
 154         if (ch == termios->c_cc[VSTOP])
 155                 channel->ch_bd->bd_ops->send_stop_character(channel);
 156         spin_unlock_irqrestore(&port->lock, lock_flags);
 157 }
 158
 159 static void jsm_tty_stop_rx(struct uart_port *port)
 160 {
 161         struct jsm_channel *channel = (struct jsm_channel *)port;
 162
 163         channel->ch_bd->bd_ops->disable_receiver(channel);
 164 }
 165
 166 static void jsm_tty_enable_ms(struct uart_port *port)
 167 {
 168         /* Nothing needed */
 169 }
 170
 171 static void jsm_tty_break(struct uart_port *port, int break_state)
 172 {
 173         unsigned long lock_flags;
 174         struct jsm_channel *channel = (struct jsm_channel *)port;
 175
 176         spin_lock_irqsave(&port->lock, lock_flags);
 177         if (break_state == -1)
 178                 channel->ch_bd->bd_ops->send_break(channel);
 179         else
 180                 channel->ch_bd->bd_ops->clear_break(channel, 0);
 181
 182         spin_unlock_irqrestore(&port->lock, lock_flags);
 183 }
 184
 185 static int jsm_tty_open(struct uart_port *port)
 186 {
 187         struct jsm_board *brd;
 188         struct jsm_channel *channel = (struct jsm_channel *)port;
 189         struct ktermios *termios;
 190
 191         /* Get board pointer from our array of majors we have allocated */
 192         brd = channel->ch_bd;
 193
 194         /*
 195          * Allocate channel buffers for read/write/error.
 196          * Set flag, so we don't get trounced on.
 197          */
 198         channel->ch_flags |= (CH_OPENING);
 199
 200         /* Drop locks, as malloc with GFP_KERNEL can sleep */
 201
 202         if (!channel->ch_rqueue) {
 203                 channel->ch_rqueue = kzalloc(RQUEUESIZE, GFP_KERNEL);
 204                 if (!channel->ch_rqueue) {
 205                         jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
 206                                 "unable to allocate read queue buf");
 207                         return -ENOMEM;
 208                 }
 209         }
 210         if (!channel->ch_equeue) {
 211                 channel->ch_equeue = kzalloc(EQUEUESIZE, GFP_KERNEL);
 212                 if (!channel->ch_equeue) {
 213                         jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
 214                                 "unable to allocate error queue buf");
 215                         return -ENOMEM;
 216                 }
 217         }
 218         if (!channel->ch_wqueue) {
 219                 channel->ch_wqueue = kzalloc(WQUEUESIZE, GFP_KERNEL);
 220                 if (!channel->ch_wqueue) {
 221                         jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
 222                                 "unable to allocate write queue buf");
 223                         return -ENOMEM;
 224                 }
 225         }
 226
 227         channel->ch_flags &= ~(CH_OPENING);
 228         /*
 229          * Initialize if neither terminal is open.
 230          */
 231         jsm_printk(OPEN, INFO, &channel->ch_bd->pci_dev,
 232                 "jsm_open: initializing channel in open...\n");
 233
 234         /*
 235          * Flush input queues.
 236          */
 237         channel->ch_r_head = channel->ch_r_tail = 0;
 238         channel->ch_e_head = channel->ch_e_tail = 0;
 239         channel->ch_w_head = channel->ch_w_tail = 0;
 240
 241         brd->bd_ops->flush_uart_write(channel);
 242         brd->bd_ops->flush_uart_read(channel);
 243
 244         channel->ch_flags = 0;
 245         channel->ch_cached_lsr = 0;
 246         channel->ch_stops_sent = 0;
 247
 248         termios = port->info->port.tty->termios;
 249         channel->ch_c_cflag     = termios->c_cflag;
 250         channel->ch_c_iflag     = termios->c_iflag;
 251         channel->ch_c_oflag     = termios->c_oflag;
 252         channel->ch_c_lflag     = termios->c_lflag;
 253         channel->ch_startc      = termios->c_cc[VSTART];
 254         channel->ch_stopc       = termios->c_cc[VSTOP];
 255
 256         /* Tell UART to init itself */
 257         brd->bd_ops->uart_init(channel);
 258
 259         /*
 260          * Run param in case we changed anything
 261          */
 262         brd->bd_ops->param(channel);
 263
 264         jsm_carrier(channel);
 265
 266         channel->ch_open_count++;
 267
 268         jsm_printk(OPEN, INFO, &channel->ch_bd->pci_dev, "finish\n");
 269         return 0;
 270 }
 271
 272 static void jsm_tty_close(struct uart_port *port)
 273 {
 274         struct jsm_board *bd;
 275         struct ktermios *ts;
 276         struct jsm_channel *channel = (struct jsm_channel *)port;
 277
 278         jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev, "start\n");
 279
 280         bd = channel->ch_bd;
 281         ts = port->info->port.tty->termios;
 282
 283         channel->ch_flags &= ~(CH_STOPI);
 284
 285         channel->ch_open_count--;
 286
 287         /*
 288          * If we have HUPCL set, lower DTR and RTS
 289          */
 290         if (channel->ch_c_cflag & HUPCL) {
 291                 jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev,
 292                         "Close. HUPCL set, dropping DTR/RTS\n");
 293
 294                 /* Drop RTS/DTR */
 295                 channel->ch_mostat &= ~(UART_MCR_DTR | UART_MCR_RTS);
 296                 bd->bd_ops->assert_modem_signals(channel);
 297         }
 298
 299         channel->ch_old_baud = 0;
 300
 301         /* Turn off UART interrupts for this port */
 302         channel->ch_bd->bd_ops->uart_off(channel);
 303
 304         jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev, "finish\n");
 305 }
 306
 307 static void jsm_tty_set_termios(struct uart_port *port,
 308                                  struct ktermios *termios,
 309                                  struct ktermios *old_termios)
 310 {
 311         unsigned long lock_flags;
 312         struct jsm_channel *channel = (struct jsm_channel *)port;
 313
 314         spin_lock_irqsave(&port->lock, lock_flags);
 315         channel->ch_c_cflag     = termios->c_cflag;
 316         channel->ch_c_iflag     = termios->c_iflag;
 317         channel->ch_c_oflag     = termios->c_oflag;
 318         channel->ch_c_lflag     = termios->c_lflag;
 319         channel->ch_startc      = termios->c_cc[VSTART];
 320         channel->ch_stopc       = termios->c_cc[VSTOP];
 321
 322         channel->ch_bd->bd_ops->param(channel);
 323         jsm_carrier(channel);
 324         spin_unlock_irqrestore(&port->lock, lock_flags);
 325 }
 326
 327 static const char *jsm_tty_type(struct uart_port *port)
 328 {
 329         return "jsm";
 330 }
 331
 332 static void jsm_tty_release_port(struct uart_port *port)
 333 {
 334 }
 335
 336 static int jsm_tty_request_port(struct uart_port *port)
 337 {
 338         return 0;
 339 }
 340
 341 static void jsm_config_port(struct uart_port *port, int flags)
 342 {
 343         port->type = PORT_JSM;
 344 }
 345
 346 static struct uart_ops jsm_ops = {
 347         .tx_empty       = jsm_tty_tx_empty,
 348         .set_mctrl      = jsm_tty_set_mctrl,
 349         .get_mctrl      = jsm_tty_get_mctrl,
 350         .stop_tx        = jsm_tty_stop_tx,
 351         .start_tx       = jsm_tty_start_tx,
 352         .send_xchar     = jsm_tty_send_xchar,
 353         .stop_rx        = jsm_tty_stop_rx,
 354         .enable_ms      = jsm_tty_enable_ms,
 355         .break_ctl      = jsm_tty_break,
 356         .startup        = jsm_tty_open,
 357         .shutdown       = jsm_tty_close,
 358         .set_termios    = jsm_tty_set_termios,
 359         .type           = jsm_tty_type,
 360         .release_port   = jsm_tty_release_port,
 361         .request_port   = jsm_tty_request_port,
 362         .config_port    = jsm_config_port,
 363 };
 364
 365 /*
 366  * jsm_tty_init()
 367  *
 368  * Init the tty subsystem.  Called once per board after board has been
 369  * downloaded and init'ed.
 370  */
 371 int __devinit jsm_tty_init(struct jsm_board *brd)
 372 {
 373         int i;
 374         void __iomem *vaddr;
 375         struct jsm_channel *ch;
 376
 377         if (!brd)
 378                 return -ENXIO;
 379
 380         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 381
 382         /*
 383          * Initialize board structure elements.
 384          */
 385
 386         brd->nasync = brd->maxports;
 387
 388         /*
 389          * Allocate channel memory that might not have been allocated
 390          * when the driver was first loaded.
 391          */
 392         for (i = 0; i < brd->nasync; i++) {
 393                 if (!brd->channels[i]) {
 394
 395                         /*
 396                          * Okay to malloc with GFP_KERNEL, we are not at
 397                          * interrupt context, and there are no locks held.
 398                          */
 399                         brd->channels[i] = kzalloc(sizeof(struct jsm_channel), GFP_KERNEL);
 400                         if (!brd->channels[i]) {
 401                                 jsm_printk(CORE, ERR, &brd->pci_dev,
 402                                         "%s:%d Unable to allocate memory for channel struct\n",
 403                                                          __FILE__, __LINE__);
 404                         }
 405                 }
 406         }
 407
 408         ch = brd->channels[0];
 409         vaddr = brd->re_map_membase;
 410
 411         /* Set up channel variables */
 412         for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
 413
 414                 if (!brd->channels[i])
 415                         continue;
 416
 417                 spin_lock_init(&ch->ch_lock);
 418
 419                 if (brd->bd_uart_offset == 0x200)
 420                         ch->ch_neo_uart =  vaddr + (brd->bd_uart_offset * i);
 421
 422                 ch->ch_bd = brd;
 423                 ch->ch_portnum = i;
 424
 425                 /* .25 second delay */
 426                 ch->ch_close_delay = 250;
 427
 428                 init_waitqueue_head(&ch->ch_flags_wait);
 429         }
 430
 431         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 432         return 0;
 433 }
 434
 435 int __devinit jsm_uart_port_init(struct jsm_board *brd)
 436 {
 437         int i;
 438         unsigned int line;
 439         struct jsm_channel *ch;
 440
 441         if (!brd)
 442                 return -ENXIO;
 443
 444         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 445
 446         /*
 447          * Initialize board structure elements.
 448          */
 449
 450         brd->nasync = brd->maxports;
 451
 452         /* Set up channel variables */
 453         for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
 454
 455                 if (!brd->channels[i])
 456                         continue;
 457
 458                 brd->channels[i]->uart_port.irq = brd->irq;
 459                 brd->channels[i]->uart_port.uartclk = 14745600;
 460                 brd->channels[i]->uart_port.type = PORT_JSM;
 461                 brd->channels[i]->uart_port.iotype = UPIO_MEM;
 462                 brd->channels[i]->uart_port.membase = brd->re_map_membase;
 463                 brd->channels[i]->uart_port.fifosize = 16;
 464                 brd->channels[i]->uart_port.ops = &jsm_ops;
 465                 line = find_first_zero_bit(linemap, MAXLINES);
 466                 if (line >= MAXLINES) {
 467                         printk(KERN_INFO "jsm: linemap is full, added device failed\n");
 468                         continue;
 469                 } else
 470                         set_bit((int)line, linemap);
 471                 brd->channels[i]->uart_port.line = line;
 472                 if (uart_add_one_port (&jsm_uart_driver, &brd->channels[i]->uart_port))
 473                         printk(KERN_INFO "jsm: add device failed\n");
 474                 else
 475                         printk(KERN_INFO "Added device \n");
 476         }
 477
 478         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 479         return 0;
 480 }
 481
 482 int jsm_remove_uart_port(struct jsm_board *brd)
 483 {
 484         int i;
 485         struct jsm_channel *ch;
 486
 487         if (!brd)
 488                 return -ENXIO;
 489
 490         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 491
 492         /*
 493          * Initialize board structure elements.
 494          */
 495
 496         brd->nasync = brd->maxports;
 497
 498         /* Set up channel variables */
 499         for (i = 0; i < brd->nasync; i++) {
 500
 501                 if (!brd->channels[i])
 502                         continue;
 503
 504                 ch = brd->channels[i];
 505
 506                 clear_bit((int)(ch->uart_port.line), linemap);
 507                 uart_remove_one_port(&jsm_uart_driver, &brd->channels[i]->uart_port);
 508         }
 509
 510         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 511         return 0;
 512 }
 513
 514 void jsm_input(struct jsm_channel *ch)
 515 {
 516         struct jsm_board *bd;
 517         struct tty_struct *tp;
 518         u32 rmask;
 519         u16 head;
 520         u16 tail;
 521         int data_len;
 522         unsigned long lock_flags;
 523         int len = 0;
 524         int n = 0;
 525         int s = 0;
 526         int i = 0;
 527
 528         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n");
 529
 530         if (!ch)
 531                 return;
 532
 533         tp = ch->uart_port.info->port.tty;
 534
 535         bd = ch->ch_bd;
 536         if(!bd)
 537                 return;
 538
 539         spin_lock_irqsave(&ch->ch_lock, lock_flags);
 540
 541         /*
 542          *Figure the number of characters in the buffer.
 543          *Exit immediately if none.
 544          */
 545
 546         rmask = RQUEUEMASK;
 547
 548         head = ch->ch_r_head & rmask;
 549         tail = ch->ch_r_tail & rmask;
 550
 551         data_len = (head - tail) & rmask;
 552         if (data_len == 0) {
 553                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 554                 return;
 555         }
 556
 557         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n");
 558
 559         /*
 560          *If the device is not open, or CREAD is off, flush
 561          *input data and return immediately.
 562          */
 563         if (!tp ||
 564                 !(tp->termios->c_cflag & CREAD) ) {
 565
 566                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 567                         "input. dropping %d bytes on port %d...\n", data_len, ch->ch_portnum);
 568                 ch->ch_r_head = tail;
 569
 570                 /* Force queue flow control to be released, if needed */
 571                 jsm_check_queue_flow_control(ch);
 572
 573                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 574                 return;
 575         }
 576
 577         /*
 578          * If we are throttled, simply don't read any data.
 579          */
 580         if (ch->ch_flags & CH_STOPI) {
 581                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 582                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 583                         "Port %d throttled, not reading any data. head: %x tail: %x\n",
 584                         ch->ch_portnum, head, tail);
 585                 return;
 586         }
 587
 588         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start 2\n");
 589
 590         if (data_len <= 0) {
 591                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 592                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "jsm_input 1\n");
 593                 return;
 594         }
 595
 596         len = tty_buffer_request_room(tp, data_len);
 597         n = len;
 598
 599         /*
 600          * n now contains the most amount of data we can copy,
 601          * bounded either by the flip buffer size or the amount
 602          * of data the card actually has pending...
 603          */
 604         while (n) {
 605                 s = ((head >= tail) ? head : RQUEUESIZE) - tail;
 606                 s = min(s, n);
 607
 608                 if (s <= 0)
 609                         break;
 610
 611                         /*
 612                          * If conditions are such that ld needs to see all
 613                          * UART errors, we will have to walk each character
 614                          * and error byte and send them to the buffer one at
 615                          * a time.
 616                          */
 617
 618                 if (I_PARMRK(tp) || I_BRKINT(tp) || I_INPCK(tp)) {
 619                         for (i = 0; i < s; i++) {
 620                                 /*
 621                                  * Give the Linux ld the flags in the
 622                                  * format it likes.
 623                                  */
 624                                 if (*(ch->ch_equeue +tail +i) & UART_LSR_BI)
 625                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i),  TTY_BREAK);
 626                                 else if (*(ch->ch_equeue +tail +i) & UART_LSR_PE)
 627                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_PARITY);
 628                                 else if (*(ch->ch_equeue +tail +i) & UART_LSR_FE)
 629                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_FRAME);
 630                                 else
 631                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_NORMAL);
 632                         }
 633                 } else {
 634                         tty_insert_flip_string(tp, ch->ch_rqueue + tail, s) ;
 635                 }
 636                 tail += s;
 637                 n -= s;
 638                 /* Flip queue if needed */
 639                 tail &= rmask;
 640         }
 641
 642         ch->ch_r_tail = tail & rmask;
 643         ch->ch_e_tail = tail & rmask;
 644         jsm_check_queue_flow_control(ch);
 645         spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 646
 647         /* Tell the tty layer its okay to "eat" the data now */
 648         tty_flip_buffer_push(tp);
 649
 650         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "finish\n");
 651 }
 652
 653 static void jsm_carrier(struct jsm_channel *ch)
 654 {
 655         struct jsm_board *bd;
 656
 657         int virt_carrier = 0;
 658         int phys_carrier = 0;
 659
 660         jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev, "start\n");
 661         if (!ch)
 662                 return;
 663
 664         bd = ch->ch_bd;
 665
 666         if (!bd)
 667                 return;
 668
 669         if (ch->ch_mistat & UART_MSR_DCD) {
 670                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 671                         "mistat: %x D_CD: %x\n", ch->ch_mistat, ch->ch_mistat & UART_MSR_DCD);
 672                 phys_carrier = 1;
 673         }
 674
 675         if (ch->ch_c_cflag & CLOCAL)
 676                 virt_carrier = 1;
 677
 678         jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 679                 "DCD: physical: %d virt: %d\n", phys_carrier, virt_carrier);
 680
 681         /*
 682          * Test for a VIRTUAL carrier transition to HIGH.
 683          */
 684         if (((ch->ch_flags & CH_FCAR) == 0) && (virt_carrier == 1)) {
 685
 686                 /*
 687                  * When carrier rises, wake any threads waiting
 688                  * for carrier in the open routine.
 689                  */
 690
 691                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 692                         "carrier: virt DCD rose\n");
 693
 694                 if (waitqueue_active(&(ch->ch_flags_wait)))
 695                         wake_up_interruptible(&ch->ch_flags_wait);
 696         }
 697
 698         /*
 699          * Test for a PHYSICAL carrier transition to HIGH.
 700          */
 701         if (((ch->ch_flags & CH_CD) == 0) && (phys_carrier == 1)) {
 702
 703                 /*
 704                  * When carrier rises, wake any threads waiting
 705                  * for carrier in the open routine.
 706                  */
 707
 708                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 709                         "carrier: physical DCD rose\n");
 710
 711                 if (waitqueue_active(&(ch->ch_flags_wait)))
 712                         wake_up_interruptible(&ch->ch_flags_wait);
 713         }
 714
 715         /*
 716          *  Test for a PHYSICAL transition to low, so long as we aren't
 717          *  currently ignoring physical transitions (which is what "virtual
 718          *  carrier" indicates).
 719          *
 720          *  The transition of the virtual carrier to low really doesn't
 721          *  matter... it really only means "ignore carrier state", not
 722          *  "make pretend that carrier is there".
 723          */
 724         if ((virt_carrier == 0) && ((ch->ch_flags & CH_CD) != 0)
 725                         && (phys_carrier == 0)) {
 726                 /*
 727                  *      When carrier drops:
 728                  *
 729                  *      Drop carrier on all open units.
 730                  *
 731                  *      Flush queues, waking up any task waiting in the
 732                  *      line discipline.
 733                  *
 734                  *      Send a hangup to the control terminal.
 735                  *
 736                  *      Enable all select calls.
 737                  */
 738                 if (waitqueue_active(&(ch->ch_flags_wait)))
 739                         wake_up_interruptible(&ch->ch_flags_wait);
 740         }
 741
 742         /*
 743          *  Make sure that our cached values reflect the current reality.
 744          */
 745         if (virt_carrier == 1)
 746                 ch->ch_flags |= CH_FCAR;
 747         else
 748                 ch->ch_flags &= ~CH_FCAR;
 749
 750         if (phys_carrier == 1)
 751                 ch->ch_flags |= CH_CD;
 752         else
 753                 ch->ch_flags &= ~CH_CD;
 754 }
 755
 756
 757 void jsm_check_queue_flow_control(struct jsm_channel *ch)
 758 {
 759         struct board_ops *bd_ops = ch->ch_bd->bd_ops;
 760         int qleft;
 761
 762         /* Store how much space we have left in the queue */
 763         if ((qleft = ch->ch_r_tail - ch->ch_r_head - 1) < 0)
 764                 qleft += RQUEUEMASK + 1;
 765
 766         /*
 767          * Check to see if we should enforce flow control on our queue because
 768          * the ld (or user) isn't reading data out of our queue fast enuf.
 769          *
 770          * NOTE: This is done based on what the current flow control of the
 771          * port is set for.
 772          *
 773          * 1) HWFLOW (RTS) - Turn off the UART's Receive interrupt.
 774          *      This will cause the UART's FIFO to back up, and force
 775          *      the RTS signal to be dropped.
 776          * 2) SWFLOW (IXOFF) - Keep trying to send a stop character to
 777          *      the other side, in hopes it will stop sending data to us.
 778          * 3) NONE - Nothing we can do.  We will simply drop any extra data
 779          *      that gets sent into us when the queue fills up.
 780          */
 781         if (qleft < 256) {
 782                 /* HWFLOW */
 783                 if (ch->ch_c_cflag & CRTSCTS) {
 784                         if(!(ch->ch_flags & CH_RECEIVER_OFF)) {
 785                                 bd_ops->disable_receiver(ch);
 786                                 ch->ch_flags |= (CH_RECEIVER_OFF);
 787                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 788                                         "Internal queue hit hilevel mark (%d)! Turning off interrupts.\n",
 789                                         qleft);
 790                         }
 791                 }
 792                 /* SWFLOW */
 793                 else if (ch->ch_c_iflag & IXOFF) {
 794                         if (ch->ch_stops_sent <= MAX_STOPS_SENT) {
 795                                 bd_ops->send_stop_character(ch);
 796                                 ch->ch_stops_sent++;
 797                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 798                                         "Sending stop char! Times sent: %x\n", ch->ch_stops_sent);
 799                         }
 800                 }
 801         }
 802
 803         /*
 804          * Check to see if we should unenforce flow control because
 805          * ld (or user) finally read enuf data out of our queue.
 806          *
 807          * NOTE: This is done based on what the current flow control of the
 808          * port is set for.
 809          *
 810          * 1) HWFLOW (RTS) - Turn back on the UART's Receive interrupt.
 811          *      This will cause the UART's FIFO to raise RTS back up,
 812          *      which will allow the other side to start sending data again.
 813          * 2) SWFLOW (IXOFF) - Send a start character to
 814          *      the other side, so it will start sending data to us again.
 815          * 3) NONE - Do nothing. Since we didn't do anything to turn off the
 816          *      other side, we don't need to do anything now.
 817          */
 818         if (qleft > (RQUEUESIZE / 2)) {
 819                 /* HWFLOW */
 820                 if (ch->ch_c_cflag & CRTSCTS) {
 821                         if (ch->ch_flags & CH_RECEIVER_OFF) {
 822                                 bd_ops->enable_receiver(ch);
 823                                 ch->ch_flags &= ~(CH_RECEIVER_OFF);
 824                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 825                                         "Internal queue hit lowlevel mark (%d)! Turning on interrupts.\n",
 826                                         qleft);
 827                         }
 828                 }
 829                 /* SWFLOW */
 830                 else if (ch->ch_c_iflag & IXOFF && ch->ch_stops_sent) {
 831                         ch->ch_stops_sent = 0;
 832                         bd_ops->send_start_character(ch);
 833                         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "Sending start char!\n");
 834                 }
 835         }
 836 }
 837
 838 /*
 839  * jsm_tty_write()
 840  *
 841  * Take data from the user or kernel and send it out to the FEP.
 842  * In here exists all the Transparent Print magic as well.
 843  */
 844 int jsm_tty_write(struct uart_port *port)
 845 {
 846         int bufcount;
 847         int data_count = 0,data_count1 =0;
 848         u16 head;
 849         u16 tail;
 850         u16 tmask;
 851         u32 remain;
 852         int temp_tail = port->info->xmit.tail;
 853         struct jsm_channel *channel = (struct jsm_channel *)port;
 854
 855         tmask = WQUEUEMASK;
 856         head = (channel->ch_w_head) & tmask;
 857         tail = (channel->ch_w_tail) & tmask;
 858
 859         if ((bufcount = tail - head - 1) < 0)
 860                 bufcount += WQUEUESIZE;
 861
 862         bufcount = min(bufcount, 56);
 863         remain = WQUEUESIZE - head;
 864
 865         data_count = 0;
 866         if (bufcount >= remain) {
 867                 bufcount -= remain;
 868                 while ((port->info->xmit.head != temp_tail) &&
 869                 (data_count < remain)) {
 870                         channel->ch_wqueue[head++] =
 871                         port->info->xmit.buf[temp_tail];
 872
 873                         temp_tail++;
 874                         temp_tail &= (UART_XMIT_SIZE - 1);
 875                         data_count++;
 876                 }
 877                 if (data_count == remain) head = 0;
 878         }
 879
 880         data_count1 = 0;
 881         if (bufcount > 0) {
 882                 remain = bufcount;
 883                 while ((port->info->xmit.head != temp_tail) &&
 884                         (data_count1 < remain)) {
 885                         channel->ch_wqueue[head++] =
 886                                 port->info->xmit.buf[temp_tail];
 887
 888                         temp_tail++;
 889                         temp_tail &= (UART_XMIT_SIZE - 1);
 890                         data_count1++;
 891
 892                 }
 893         }
 894
 895         port->info->xmit.tail = temp_tail;
 896
 897         data_count += data_count1;
 898         if (data_count) {
 899                 head &= tmask;
 900                 channel->ch_w_head = head;
 901         }
 902
 903         if (data_count) {
 904                 channel->ch_bd->bd_ops->copy_data_from_queue_to_uart(channel);
 905         }
 906
 907         return data_count;
 908 }