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 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
 146         spin_lock_irqsave(&port->lock, lock_flags);
 147         if (ch == port->info->tty->termios->c_cc[VSTART])
 148                 channel->ch_bd->bd_ops->send_start_character(channel);
 149
 150         if (ch == port->info->tty->termios->c_cc[VSTOP])
 151                 channel->ch_bd->bd_ops->send_stop_character(channel);
 152         spin_unlock_irqrestore(&port->lock, lock_flags);
 153 }
 154
 155 static void jsm_tty_stop_rx(struct uart_port *port)
 156 {
 157         struct jsm_channel *channel = (struct jsm_channel *)port;
 158
 159         channel->ch_bd->bd_ops->disable_receiver(channel);
 160 }
 161
 162 static void jsm_tty_break(struct uart_port *port, int break_state)
 163 {
 164         unsigned long lock_flags;
 165         struct jsm_channel *channel = (struct jsm_channel *)port;
 166
 167         spin_lock_irqsave(&port->lock, lock_flags);
 168         if (break_state == -1)
 169                 channel->ch_bd->bd_ops->send_break(channel);
 170         else
 171                 channel->ch_bd->bd_ops->clear_break(channel, 0);
 172
 173         spin_unlock_irqrestore(&port->lock, lock_flags);
 174 }
 175
 176 static int jsm_tty_open(struct uart_port *port)
 177 {
 178         struct jsm_board *brd;
 179         int rc = 0;
 180         struct jsm_channel *channel = (struct jsm_channel *)port;
 181
 182         /* Get board pointer from our array of majors we have allocated */
 183         brd = channel->ch_bd;
 184
 185         /*
 186          * Allocate channel buffers for read/write/error.
 187          * Set flag, so we don't get trounced on.
 188          */
 189         channel->ch_flags |= (CH_OPENING);
 190
 191         /* Drop locks, as malloc with GFP_KERNEL can sleep */
 192
 193         if (!channel->ch_rqueue) {
 194                 channel->ch_rqueue = (u8 *) kmalloc(RQUEUESIZE, GFP_KERNEL);
 195                 if (!channel->ch_rqueue) {
 196                         jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
 197                                 "unable to allocate read queue buf");
 198                         return -ENOMEM;
 199                 }
 200                 memset(channel->ch_rqueue, 0, RQUEUESIZE);
 201         }
 202         if (!channel->ch_equeue) {
 203                 channel->ch_equeue = (u8 *) kmalloc(EQUEUESIZE, GFP_KERNEL);
 204                 if (!channel->ch_equeue) {
 205                         jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
 206                                 "unable to allocate error queue buf");
 207                         return -ENOMEM;
 208                 }
 209                 memset(channel->ch_equeue, 0, EQUEUESIZE);
 210         }
 211         if (!channel->ch_wqueue) {
 212                 channel->ch_wqueue = (u8 *) kmalloc(WQUEUESIZE, GFP_KERNEL);
 213                 if (!channel->ch_wqueue) {
 214                         jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
 215                                 "unable to allocate write queue buf");
 216                         return -ENOMEM;
 217                 }
 218                 memset(channel->ch_wqueue, 0, WQUEUESIZE);
 219         }
 220
 221         channel->ch_flags &= ~(CH_OPENING);
 222         /*
 223          * Initialize if neither terminal is open.
 224          */
 225         jsm_printk(OPEN, INFO, &channel->ch_bd->pci_dev,
 226                 "jsm_open: initializing channel in open...\n");
 227
 228         /*
 229          * Flush input queues.
 230          */
 231         channel->ch_r_head = channel->ch_r_tail = 0;
 232         channel->ch_e_head = channel->ch_e_tail = 0;
 233         channel->ch_w_head = channel->ch_w_tail = 0;
 234
 235         brd->bd_ops->flush_uart_write(channel);
 236         brd->bd_ops->flush_uart_read(channel);
 237
 238         channel->ch_flags = 0;
 239         channel->ch_cached_lsr = 0;
 240         channel->ch_stops_sent = 0;
 241
 242         channel->ch_c_cflag     = port->info->tty->termios->c_cflag;
 243         channel->ch_c_iflag     = port->info->tty->termios->c_iflag;
 244         channel->ch_c_oflag     = port->info->tty->termios->c_oflag;
 245         channel->ch_c_lflag     = port->info->tty->termios->c_lflag;
 246         channel->ch_startc = port->info->tty->termios->c_cc[VSTART];
 247         channel->ch_stopc = port->info->tty->termios->c_cc[VSTOP];
 248
 249         /* Tell UART to init itself */
 250         brd->bd_ops->uart_init(channel);
 251
 252         /*
 253          * Run param in case we changed anything
 254          */
 255         brd->bd_ops->param(channel);
 256
 257         jsm_carrier(channel);
 258
 259         channel->ch_open_count++;
 260
 261         jsm_printk(OPEN, INFO, &channel->ch_bd->pci_dev, "finish\n");
 262         return rc;
 263 }
 264
 265 static void jsm_tty_close(struct uart_port *port)
 266 {
 267         struct jsm_board *bd;
 268         struct termios *ts;
 269         struct jsm_channel *channel = (struct jsm_channel *)port;
 270
 271         jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev, "start\n");
 272
 273         bd = channel->ch_bd;
 274         ts = channel->uart_port.info->tty->termios;
 275
 276         channel->ch_flags &= ~(CH_STOPI);
 277
 278         channel->ch_open_count--;
 279
 280         /*
 281          * If we have HUPCL set, lower DTR and RTS
 282          */
 283         if (channel->ch_c_cflag & HUPCL) {
 284                 jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev,
 285                         "Close. HUPCL set, dropping DTR/RTS\n");
 286
 287                 /* Drop RTS/DTR */
 288                 channel->ch_mostat &= ~(UART_MCR_DTR | UART_MCR_RTS);
 289                 bd->bd_ops->assert_modem_signals(channel);
 290         }
 291
 292         channel->ch_old_baud = 0;
 293
 294         /* Turn off UART interrupts for this port */
 295         channel->ch_bd->bd_ops->uart_off(channel);
 296
 297         jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev, "finish\n");
 298 }
 299
 300 static void jsm_tty_set_termios(struct uart_port *port,
 301                                  struct termios *termios,
 302                                  struct termios *old_termios)
 303 {
 304         unsigned long lock_flags;
 305         struct jsm_channel *channel = (struct jsm_channel *)port;
 306
 307         spin_lock_irqsave(&port->lock, lock_flags);
 308         channel->ch_c_cflag     = termios->c_cflag;
 309         channel->ch_c_iflag     = termios->c_iflag;
 310         channel->ch_c_oflag     = termios->c_oflag;
 311         channel->ch_c_lflag     = termios->c_lflag;
 312         channel->ch_startc      = termios->c_cc[VSTART];
 313         channel->ch_stopc       = termios->c_cc[VSTOP];
 314
 315         channel->ch_bd->bd_ops->param(channel);
 316         jsm_carrier(channel);
 317         spin_unlock_irqrestore(&port->lock, lock_flags);
 318 }
 319
 320 static const char *jsm_tty_type(struct uart_port *port)
 321 {
 322         return "jsm";
 323 }
 324
 325 static void jsm_tty_release_port(struct uart_port *port)
 326 {
 327 }
 328
 329 static int jsm_tty_request_port(struct uart_port *port)
 330 {
 331         return 0;
 332 }
 333
 334 static void jsm_config_port(struct uart_port *port, int flags)
 335 {
 336         port->type = PORT_JSM;
 337 }
 338
 339 static struct uart_ops jsm_ops = {
 340         .tx_empty       = jsm_tty_tx_empty,
 341         .set_mctrl      = jsm_tty_set_mctrl,
 342         .get_mctrl      = jsm_tty_get_mctrl,
 343         .stop_tx        = jsm_tty_stop_tx,
 344         .start_tx       = jsm_tty_start_tx,
 345         .send_xchar     = jsm_tty_send_xchar,
 346         .stop_rx        = jsm_tty_stop_rx,
 347         .break_ctl      = jsm_tty_break,
 348         .startup        = jsm_tty_open,
 349         .shutdown       = jsm_tty_close,
 350         .set_termios    = jsm_tty_set_termios,
 351         .type           = jsm_tty_type,
 352         .release_port   = jsm_tty_release_port,
 353         .request_port   = jsm_tty_request_port,
 354         .config_port    = jsm_config_port,
 355 };
 356
 357 /*
 358  * jsm_tty_init()
 359  *
 360  * Init the tty subsystem.  Called once per board after board has been
 361  * downloaded and init'ed.
 362  */
 363 int jsm_tty_init(struct jsm_board *brd)
 364 {
 365         int i;
 366         void __iomem *vaddr;
 367         struct jsm_channel *ch;
 368
 369         if (!brd)
 370                 return -ENXIO;
 371
 372         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 373
 374         /*
 375          * Initialize board structure elements.
 376          */
 377
 378         brd->nasync = brd->maxports;
 379
 380         /*
 381          * Allocate channel memory that might not have been allocated
 382          * when the driver was first loaded.
 383          */
 384         for (i = 0; i < brd->nasync; i++) {
 385                 if (!brd->channels[i]) {
 386
 387                         /*
 388                          * Okay to malloc with GFP_KERNEL, we are not at
 389                          * interrupt context, and there are no locks held.
 390                          */
 391                         brd->channels[i] = kmalloc(sizeof(struct jsm_channel), GFP_KERNEL);
 392                         if (!brd->channels[i]) {
 393                                 jsm_printk(CORE, ERR, &brd->pci_dev,
 394                                         "%s:%d Unable to allocate memory for channel struct\n",
 395                                                          __FILE__, __LINE__);
 396                         }
 397                         memset(brd->channels[i], 0, sizeof(struct jsm_channel));
 398                 }
 399         }
 400
 401         ch = brd->channels[0];
 402         vaddr = brd->re_map_membase;
 403
 404         /* Set up channel variables */
 405         for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
 406
 407                 if (!brd->channels[i])
 408                         continue;
 409
 410                 spin_lock_init(&ch->ch_lock);
 411
 412                 if (brd->bd_uart_offset == 0x200)
 413                         ch->ch_neo_uart =  vaddr + (brd->bd_uart_offset * i);
 414
 415                 ch->ch_bd = brd;
 416                 ch->ch_portnum = i;
 417
 418                 /* .25 second delay */
 419                 ch->ch_close_delay = 250;
 420
 421                 init_waitqueue_head(&ch->ch_flags_wait);
 422         }
 423
 424         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 425         return 0;
 426 }
 427
 428 int jsm_uart_port_init(struct jsm_board *brd)
 429 {
 430         int i;
 431         struct jsm_channel *ch;
 432
 433         if (!brd)
 434                 return -ENXIO;
 435
 436         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 437
 438         /*
 439          * Initialize board structure elements.
 440          */
 441
 442         brd->nasync = brd->maxports;
 443
 444         /* Set up channel variables */
 445         for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
 446
 447                 if (!brd->channels[i])
 448                         continue;
 449
 450                 brd->channels[i]->uart_port.irq = brd->irq;
 451                 brd->channels[i]->uart_port.type = PORT_JSM;
 452                 brd->channels[i]->uart_port.iotype = UPIO_MEM;
 453                 brd->channels[i]->uart_port.membase = brd->re_map_membase;
 454                 brd->channels[i]->uart_port.fifosize = 16;
 455                 brd->channels[i]->uart_port.ops = &jsm_ops;
 456                 brd->channels[i]->uart_port.line = brd->channels[i]->ch_portnum + brd->boardnum * 2;
 457                 if (uart_add_one_port (&jsm_uart_driver, &brd->channels[i]->uart_port))
 458                         printk(KERN_INFO "Added device failed\n");
 459                 else
 460                         printk(KERN_INFO "Added device \n");
 461         }
 462
 463         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 464         return 0;
 465 }
 466
 467 int jsm_remove_uart_port(struct jsm_board *brd)
 468 {
 469         int i;
 470         struct jsm_channel *ch;
 471
 472         if (!brd)
 473                 return -ENXIO;
 474
 475         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 476
 477         /*
 478          * Initialize board structure elements.
 479          */
 480
 481         brd->nasync = brd->maxports;
 482
 483         /* Set up channel variables */
 484         for (i = 0; i < brd->nasync; i++) {
 485
 486                 if (!brd->channels[i])
 487                         continue;
 488
 489                 ch = brd->channels[i];
 490
 491                 uart_remove_one_port(&jsm_uart_driver, &brd->channels[i]->uart_port);
 492         }
 493
 494         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 495         return 0;
 496 }
 497
 498 void jsm_input(struct jsm_channel *ch)
 499 {
 500         struct jsm_board *bd;
 501         struct tty_struct *tp;
 502         struct tty_ldisc *ld;
 503         u32 rmask;
 504         u16 head;
 505         u16 tail;
 506         int data_len;
 507         unsigned long lock_flags;
 508         int flip_len = 0;
 509         int len = 0;
 510         int n = 0;
 511         int s = 0;
 512         int i = 0;
 513
 514         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n");
 515
 516         if (!ch)
 517                 return;
 518
 519         tp = ch->uart_port.info->tty;
 520
 521         bd = ch->ch_bd;
 522         if(!bd)
 523                 return;
 524
 525         spin_lock_irqsave(&ch->ch_lock, lock_flags);
 526
 527         /*
 528          *Figure the number of characters in the buffer.
 529          *Exit immediately if none.
 530          */
 531
 532         rmask = RQUEUEMASK;
 533
 534         head = ch->ch_r_head & rmask;
 535         tail = ch->ch_r_tail & rmask;
 536
 537         data_len = (head - tail) & rmask;
 538         if (data_len == 0) {
 539                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 540                 return;
 541         }
 542
 543         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n");
 544
 545         /*
 546          *If the device is not open, or CREAD is off, flush
 547          *input data and return immediately.
 548          */
 549         if (!tp ||
 550                 !(tp->termios->c_cflag & CREAD) ) {
 551
 552                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 553                         "input. dropping %d bytes on port %d...\n", data_len, ch->ch_portnum);
 554                 ch->ch_r_head = tail;
 555
 556                 /* Force queue flow control to be released, if needed */
 557                 jsm_check_queue_flow_control(ch);
 558
 559                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 560                 return;
 561         }
 562
 563         /*
 564          * If we are throttled, simply don't read any data.
 565          */
 566         if (ch->ch_flags & CH_STOPI) {
 567                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 568                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 569                         "Port %d throttled, not reading any data. head: %x tail: %x\n",
 570                         ch->ch_portnum, head, tail);
 571                 return;
 572         }
 573
 574         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start 2\n");
 575
 576         /*
 577          * If the rxbuf is empty and we are not throttled, put as much
 578          * as we can directly into the linux TTY buffer.
 579          *
 580          */
 581         flip_len = TTY_FLIPBUF_SIZE;
 582
 583         len = min(data_len, flip_len);
 584         len = min(len, (N_TTY_BUF_SIZE - 1) - tp->read_cnt);
 585         ld = tty_ldisc_ref(tp);
 586
 587         /*
 588          * If the DONT_FLIP flag is on, don't flush our buffer, and act
 589          * like the ld doesn't have any space to put the data right now.
 590          */
 591         if (test_bit(TTY_DONT_FLIP, &tp->flags))
 592                 len = 0;
 593
 594         /*
 595          * If we were unable to get a reference to the ld,
 596          * don't flush our buffer, and act like the ld doesn't
 597          * have any space to put the data right now.
 598          */
 599         if (!ld) {
 600                 len = 0;
 601         } else {
 602                 /*
 603                  * If ld doesn't have a pointer to a receive_buf function,
 604                  * flush the data, then act like the ld doesn't have any
 605                  * space to put the data right now.
 606                  */
 607                 if (!ld->receive_buf) {
 608                                 ch->ch_r_head = ch->ch_r_tail;
 609                                 len = 0;
 610                 }
 611         }
 612
 613         if (len <= 0) {
 614                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 615                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "jsm_input 1\n");
 616                 if (ld)
 617                         tty_ldisc_deref(ld);
 618                 return;
 619         }
 620
 621         len = tty_buffer_request_room(tp, len);
 622         n = len;
 623
 624         /*
 625          * n now contains the most amount of data we can copy,
 626          * bounded either by the flip buffer size or the amount
 627          * of data the card actually has pending...
 628          */
 629         while (n) {
 630                 s = ((head >= tail) ? head : RQUEUESIZE) - tail;
 631                 s = min(s, n);
 632
 633                 if (s <= 0)
 634                         break;
 635
 636                         /*
 637                          * If conditions are such that ld needs to see all
 638                          * UART errors, we will have to walk each character
 639                          * and error byte and send them to the buffer one at
 640                          * a time.
 641                          */
 642
 643                 if (I_PARMRK(tp) || I_BRKINT(tp) || I_INPCK(tp)) {
 644                         for (i = 0; i < s; i++) {
 645                                 /*
 646                                  * Give the Linux ld the flags in the
 647                                  * format it likes.
 648                                  */
 649                                 if (*(ch->ch_equeue +tail +i) & UART_LSR_BI)
 650                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i),  TTY_BREAK);
 651                                 else if (*(ch->ch_equeue +tail +i) & UART_LSR_PE)
 652                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_PARITY);
 653                                 else if (*(ch->ch_equeue +tail +i) & UART_LSR_FE)
 654                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_FRAME);
 655                                 else
 656                                 tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_NORMAL);
 657                         }
 658                 } else {
 659                         tty_insert_flip_string(tp, ch->ch_rqueue + tail, s) ;
 660                 }
 661                 tail += s;
 662                 n -= s;
 663                 /* Flip queue if needed */
 664                 tail &= rmask;
 665         }
 666
 667         ch->ch_r_tail = tail & rmask;
 668         ch->ch_e_tail = tail & rmask;
 669         jsm_check_queue_flow_control(ch);
 670         spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 671
 672         /* Tell the tty layer its okay to "eat" the data now */
 673         tty_flip_buffer_push(tp);
 674
 675         if (ld)
 676                 tty_ldisc_deref(ld);
 677
 678         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "finish\n");
 679 }
 680
 681 static void jsm_carrier(struct jsm_channel *ch)
 682 {
 683         struct jsm_board *bd;
 684
 685         int virt_carrier = 0;
 686         int phys_carrier = 0;
 687
 688         jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev, "start\n");
 689         if (!ch)
 690                 return;
 691
 692         bd = ch->ch_bd;
 693
 694         if (!bd)
 695                 return;
 696
 697         if (ch->ch_mistat & UART_MSR_DCD) {
 698                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 699                         "mistat: %x D_CD: %x\n", ch->ch_mistat, ch->ch_mistat & UART_MSR_DCD);
 700                 phys_carrier = 1;
 701         }
 702
 703         if (ch->ch_c_cflag & CLOCAL)
 704                 virt_carrier = 1;
 705
 706         jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 707                 "DCD: physical: %d virt: %d\n", phys_carrier, virt_carrier);
 708
 709         /*
 710          * Test for a VIRTUAL carrier transition to HIGH.
 711          */
 712         if (((ch->ch_flags & CH_FCAR) == 0) && (virt_carrier == 1)) {
 713
 714                 /*
 715                  * When carrier rises, wake any threads waiting
 716                  * for carrier in the open routine.
 717                  */
 718
 719                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 720                         "carrier: virt DCD rose\n");
 721
 722                 if (waitqueue_active(&(ch->ch_flags_wait)))
 723                         wake_up_interruptible(&ch->ch_flags_wait);
 724         }
 725
 726         /*
 727          * Test for a PHYSICAL carrier transition to HIGH.
 728          */
 729         if (((ch->ch_flags & CH_CD) == 0) && (phys_carrier == 1)) {
 730
 731                 /*
 732                  * When carrier rises, wake any threads waiting
 733                  * for carrier in the open routine.
 734                  */
 735
 736                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 737                         "carrier: physical DCD rose\n");
 738
 739                 if (waitqueue_active(&(ch->ch_flags_wait)))
 740                         wake_up_interruptible(&ch->ch_flags_wait);
 741         }
 742
 743         /*
 744          *  Test for a PHYSICAL transition to low, so long as we aren't
 745          *  currently ignoring physical transitions (which is what "virtual
 746          *  carrier" indicates).
 747          *
 748          *  The transition of the virtual carrier to low really doesn't
 749          *  matter... it really only means "ignore carrier state", not
 750          *  "make pretend that carrier is there".
 751          */
 752         if ((virt_carrier == 0) && ((ch->ch_flags & CH_CD) != 0)
 753                         && (phys_carrier == 0)) {
 754                 /*
 755                  *      When carrier drops:
 756                  *
 757                  *      Drop carrier on all open units.
 758                  *
 759                  *      Flush queues, waking up any task waiting in the
 760                  *      line discipline.
 761                  *
 762                  *      Send a hangup to the control terminal.
 763                  *
 764                  *      Enable all select calls.
 765                  */
 766                 if (waitqueue_active(&(ch->ch_flags_wait)))
 767                         wake_up_interruptible(&ch->ch_flags_wait);
 768         }
 769
 770         /*
 771          *  Make sure that our cached values reflect the current reality.
 772          */
 773         if (virt_carrier == 1)
 774                 ch->ch_flags |= CH_FCAR;
 775         else
 776                 ch->ch_flags &= ~CH_FCAR;
 777
 778         if (phys_carrier == 1)
 779                 ch->ch_flags |= CH_CD;
 780         else
 781                 ch->ch_flags &= ~CH_CD;
 782 }
 783
 784
 785 void jsm_check_queue_flow_control(struct jsm_channel *ch)
 786 {
 787         int qleft = 0;
 788
 789         /* Store how much space we have left in the queue */
 790         if ((qleft = ch->ch_r_tail - ch->ch_r_head - 1) < 0)
 791                 qleft += RQUEUEMASK + 1;
 792
 793         /*
 794          * Check to see if we should enforce flow control on our queue because
 795          * the ld (or user) isn't reading data out of our queue fast enuf.
 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 off the UART's Receive interrupt.
 801          *      This will cause the UART's FIFO to back up, and force
 802          *      the RTS signal to be dropped.
 803          * 2) SWFLOW (IXOFF) - Keep trying to send a stop character to
 804          *      the other side, in hopes it will stop sending data to us.
 805          * 3) NONE - Nothing we can do.  We will simply drop any extra data
 806          *      that gets sent into us when the queue fills up.
 807          */
 808         if (qleft < 256) {
 809                 /* HWFLOW */
 810                 if (ch->ch_c_cflag & CRTSCTS) {
 811                         if(!(ch->ch_flags & CH_RECEIVER_OFF)) {
 812                                 ch->ch_bd->bd_ops->disable_receiver(ch);
 813                                 ch->ch_flags |= (CH_RECEIVER_OFF);
 814                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 815                                         "Internal queue hit hilevel mark (%d)! Turning off interrupts.\n",
 816                                         qleft);
 817                         }
 818                 }
 819                 /* SWFLOW */
 820                 else if (ch->ch_c_iflag & IXOFF) {
 821                         if (ch->ch_stops_sent <= MAX_STOPS_SENT) {
 822                                 ch->ch_bd->bd_ops->send_stop_character(ch);
 823                                 ch->ch_stops_sent++;
 824                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 825                                         "Sending stop char! Times sent: %x\n", ch->ch_stops_sent);
 826                         }
 827                 }
 828         }
 829
 830         /*
 831          * Check to see if we should unenforce flow control because
 832          * ld (or user) finally read enuf data out of our queue.
 833          *
 834          * NOTE: This is done based on what the current flow control of the
 835          * port is set for.
 836          *
 837          * 1) HWFLOW (RTS) - Turn back on the UART's Receive interrupt.
 838          *      This will cause the UART's FIFO to raise RTS back up,
 839          *      which will allow the other side to start sending data again.
 840          * 2) SWFLOW (IXOFF) - Send a start character to
 841          *      the other side, so it will start sending data to us again.
 842          * 3) NONE - Do nothing. Since we didn't do anything to turn off the
 843          *      other side, we don't need to do anything now.
 844          */
 845         if (qleft > (RQUEUESIZE / 2)) {
 846                 /* HWFLOW */
 847                 if (ch->ch_c_cflag & CRTSCTS) {
 848                         if (ch->ch_flags & CH_RECEIVER_OFF) {
 849                                 ch->ch_bd->bd_ops->enable_receiver(ch);
 850                                 ch->ch_flags &= ~(CH_RECEIVER_OFF);
 851                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 852                                         "Internal queue hit lowlevel mark (%d)! Turning on interrupts.\n",
 853                                         qleft);
 854                         }
 855                 }
 856                 /* SWFLOW */
 857                 else if (ch->ch_c_iflag & IXOFF && ch->ch_stops_sent) {
 858                         ch->ch_stops_sent = 0;
 859                         ch->ch_bd->bd_ops->send_start_character(ch);
 860                         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "Sending start char!\n");
 861                 }
 862         }
 863 }
 864
 865 /*
 866  * jsm_tty_write()
 867  *
 868  * Take data from the user or kernel and send it out to the FEP.
 869  * In here exists all the Transparent Print magic as well.
 870  */
 871 int jsm_tty_write(struct uart_port *port)
 872 {
 873         int bufcount = 0, n = 0;
 874         int data_count = 0,data_count1 =0;
 875         u16 head;
 876         u16 tail;
 877         u16 tmask;
 878         u32 remain;
 879         int temp_tail = port->info->xmit.tail;
 880         struct jsm_channel *channel = (struct jsm_channel *)port;
 881
 882         tmask = WQUEUEMASK;
 883         head = (channel->ch_w_head) & tmask;
 884         tail = (channel->ch_w_tail) & tmask;
 885
 886         if ((bufcount = tail - head - 1) < 0)
 887                 bufcount += WQUEUESIZE;
 888
 889         n = bufcount;
 890
 891         n = min(n, 56);
 892         remain = WQUEUESIZE - head;
 893
 894         data_count = 0;
 895         if (n >= remain) {
 896                 n -= remain;
 897                 while ((port->info->xmit.head != temp_tail) &&
 898                 (data_count < remain)) {
 899                         channel->ch_wqueue[head++] =
 900                         port->info->xmit.buf[temp_tail];
 901
 902                         temp_tail++;
 903                         temp_tail &= (UART_XMIT_SIZE - 1);
 904                         data_count++;
 905                 }
 906                 if (data_count == remain) head = 0;
 907         }
 908
 909         data_count1 = 0;
 910         if (n > 0) {
 911                 remain = n;
 912                 while ((port->info->xmit.head != temp_tail) &&
 913                         (data_count1 < remain)) {
 914                         channel->ch_wqueue[head++] =
 915                                 port->info->xmit.buf[temp_tail];
 916
 917                         temp_tail++;
 918                         temp_tail &= (UART_XMIT_SIZE - 1);
 919                         data_count1++;
 920
 921                 }
 922         }
 923
 924         port->info->xmit.tail = temp_tail;
 925
 926         data_count += data_count1;
 927         if (data_count) {
 928                 head &= tmask;
 929                 channel->ch_w_head = head;
 930         }
 931
 932         if (data_count) {
 933                 channel->ch_bd->bd_ops->copy_data_from_queue_to_uart(channel);
 934         }
 935
 936         return data_count;
 937 }