drivers/tty/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 #include <linux/slab.h>
  34
  35 #include "jsm.h"
  36
  37 static DECLARE_BITMAP(linemap, MAXLINES);
  38
  39 static void jsm_carrier(struct jsm_channel *ch);
  40
  41 static inline int jsm_get_mstat(struct jsm_channel *ch)
  42 {
  43         unsigned char mstat;
  44         unsigned result;
  45
  46         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "start\n");
  47
  48         mstat = (ch->ch_mostat | ch->ch_mistat);
  49
  50         result = 0;
  51
  52         if (mstat & UART_MCR_DTR)
  53                 result |= TIOCM_DTR;
  54         if (mstat & UART_MCR_RTS)
  55                 result |= TIOCM_RTS;
  56         if (mstat & UART_MSR_CTS)
  57                 result |= TIOCM_CTS;
  58         if (mstat & UART_MSR_DSR)
  59                 result |= TIOCM_DSR;
  60         if (mstat & UART_MSR_RI)
  61                 result |= TIOCM_RI;
  62         if (mstat & UART_MSR_DCD)
  63                 result |= TIOCM_CD;
  64
  65         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "finish\n");
  66         return result;
  67 }
  68
  69 static unsigned int jsm_tty_tx_empty(struct uart_port *port)
  70 {
  71         return TIOCSER_TEMT;
  72 }
  73
  74 /*
  75  * Return modem signals to ld.
  76  */
  77 static unsigned int jsm_tty_get_mctrl(struct uart_port *port)
  78 {
  79         int result;
  80         struct jsm_channel *channel = (struct jsm_channel *)port;
  81
  82         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
  83
  84         result = jsm_get_mstat(channel);
  85
  86         if (result < 0)
  87                 return -ENXIO;
  88
  89         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
  90
  91         return result;
  92 }
  93
  94 /*
  95  * jsm_set_modem_info()
  96  *
  97  * Set modem signals, called by ld.
  98  */
  99 static void jsm_tty_set_mctrl(struct uart_port *port, unsigned int mctrl)
 100 {
 101         struct jsm_channel *channel = (struct jsm_channel *)port;
 102
 103         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
 104
 105         if (mctrl & TIOCM_RTS)
 106                 channel->ch_mostat |= UART_MCR_RTS;
 107         else
 108                 channel->ch_mostat &= ~UART_MCR_RTS;
 109
 110         if (mctrl & TIOCM_DTR)
 111                 channel->ch_mostat |= UART_MCR_DTR;
 112         else
 113                 channel->ch_mostat &= ~UART_MCR_DTR;
 114
 115         channel->ch_bd->bd_ops->assert_modem_signals(channel);
 116
 117         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
 118         udelay(10);
 119 }
 120
 121 static void jsm_tty_start_tx(struct uart_port *port)
 122 {
 123         struct jsm_channel *channel = (struct jsm_channel *)port;
 124
 125         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
 126
 127         channel->ch_flags &= ~(CH_STOP);
 128         jsm_tty_write(port);
 129
 130         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
 131 }
 132
 133 static void jsm_tty_stop_tx(struct uart_port *port)
 134 {
 135         struct jsm_channel *channel = (struct jsm_channel *)port;
 136
 137         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
 138
 139         channel->ch_flags |= (CH_STOP);
 140
 141         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
 142 }
 143
 144 static void jsm_tty_send_xchar(struct uart_port *port, char ch)
 145 {
 146         unsigned long lock_flags;
 147         struct jsm_channel *channel = (struct jsm_channel *)port;
 148         struct ktermios *termios;
 149
 150         spin_lock_irqsave(&port->lock, lock_flags);
 151         termios = port->state->port.tty->termios;
 152         if (ch == termios->c_cc[VSTART])
 153                 channel->ch_bd->bd_ops->send_start_character(channel);
 154
 155         if (ch == termios->c_cc[VSTOP])
 156                 channel->ch_bd->bd_ops->send_stop_character(channel);
 157         spin_unlock_irqrestore(&port->lock, lock_flags);
 158 }
 159
 160 static void jsm_tty_stop_rx(struct uart_port *port)
 161 {
 162         struct jsm_channel *channel = (struct jsm_channel *)port;
 163
 164         channel->ch_bd->bd_ops->disable_receiver(channel);
 165 }
 166
 167 static void jsm_tty_enable_ms(struct uart_port *port)
 168 {
 169         /* Nothing needed */
 170 }
 171
 172 static void jsm_tty_break(struct uart_port *port, int break_state)
 173 {
 174         unsigned long lock_flags;
 175         struct jsm_channel *channel = (struct jsm_channel *)port;
 176
 177         spin_lock_irqsave(&port->lock, lock_flags);
 178         if (break_state == -1)
 179                 channel->ch_bd->bd_ops->send_break(channel);
 180         else
 181                 channel->ch_bd->bd_ops->clear_break(channel, 0);
 182
 183         spin_unlock_irqrestore(&port->lock, lock_flags);
 184 }
 185
 186 static int jsm_tty_open(struct uart_port *port)
 187 {
 188         struct jsm_board *brd;
 189         struct jsm_channel *channel = (struct jsm_channel *)port;
 190         struct ktermios *termios;
 191
 192         /* Get board pointer from our array of majors we have allocated */
 193         brd = channel->ch_bd;
 194
 195         /*
 196          * Allocate channel buffers for read/write/error.
 197          * Set flag, so we don't get trounced on.
 198          */
 199         channel->ch_flags |= (CH_OPENING);
 200
 201         /* Drop locks, as malloc with GFP_KERNEL can sleep */
 202
 203         if (!channel->ch_rqueue) {
 204                 channel->ch_rqueue = kzalloc(RQUEUESIZE, GFP_KERNEL);
 205                 if (!channel->ch_rqueue) {
 206                         jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
 207                                 "unable to allocate read queue buf");
 208                         return -ENOMEM;
 209                 }
 210         }
 211         if (!channel->ch_equeue) {
 212                 channel->ch_equeue = kzalloc(EQUEUESIZE, GFP_KERNEL);
 213                 if (!channel->ch_equeue) {
 214                         jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
 215                                 "unable to allocate error queue buf");
 216                         return -ENOMEM;
 217                 }
 218         }
 219         if (!channel->ch_wqueue) {
 220                 channel->ch_wqueue = kzalloc(WQUEUESIZE, GFP_KERNEL);
 221                 if (!channel->ch_wqueue) {
 222                         jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
 223                                 "unable to allocate write queue buf");
 224                         return -ENOMEM;
 225                 }
 226         }
 227
 228         channel->ch_flags &= ~(CH_OPENING);
 229         /*
 230          * Initialize if neither terminal is open.
 231          */
 232         jsm_printk(OPEN, INFO, &channel->ch_bd->pci_dev,
 233                 "jsm_open: initializing channel in open...\n");
 234
 235         /*
 236          * Flush input queues.
 237          */
 238         channel->ch_r_head = channel->ch_r_tail = 0;
 239         channel->ch_e_head = channel->ch_e_tail = 0;
 240         channel->ch_w_head = channel->ch_w_tail = 0;
 241
 242         brd->bd_ops->flush_uart_write(channel);
 243         brd->bd_ops->flush_uart_read(channel);
 244
 245         channel->ch_flags = 0;
 246         channel->ch_cached_lsr = 0;
 247         channel->ch_stops_sent = 0;
 248
 249         termios = port->state->port.tty->termios;
 250         channel->ch_c_cflag     = termios->c_cflag;
 251         channel->ch_c_iflag     = termios->c_iflag;
 252         channel->ch_c_oflag     = termios->c_oflag;
 253         channel->ch_c_lflag     = termios->c_lflag;
 254         channel->ch_startc      = termios->c_cc[VSTART];
 255         channel->ch_stopc       = termios->c_cc[VSTOP];
 256
 257         /* Tell UART to init itself */
 258         brd->bd_ops->uart_init(channel);
 259
 260         /*
 261          * Run param in case we changed anything
 262          */
 263         brd->bd_ops->param(channel);
 264
 265         jsm_carrier(channel);
 266
 267         channel->ch_open_count++;
 268
 269         jsm_printk(OPEN, INFO, &channel->ch_bd->pci_dev, "finish\n");
 270         return 0;
 271 }
 272
 273 static void jsm_tty_close(struct uart_port *port)
 274 {
 275         struct jsm_board *bd;
 276         struct ktermios *ts;
 277         struct jsm_channel *channel = (struct jsm_channel *)port;
 278
 279         jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev, "start\n");
 280
 281         bd = channel->ch_bd;
 282         ts = port->state->port.tty->termios;
 283
 284         channel->ch_flags &= ~(CH_STOPI);
 285
 286         channel->ch_open_count--;
 287
 288         /*
 289          * If we have HUPCL set, lower DTR and RTS
 290          */
 291         if (channel->ch_c_cflag & HUPCL) {
 292                 jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev,
 293                         "Close. HUPCL set, dropping DTR/RTS\n");
 294
 295                 /* Drop RTS/DTR */
 296                 channel->ch_mostat &= ~(UART_MCR_DTR | UART_MCR_RTS);
 297                 bd->bd_ops->assert_modem_signals(channel);
 298         }
 299
 300         /* Turn off UART interrupts for this port */
 301         channel->ch_bd->bd_ops->uart_off(channel);
 302
 303         jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev, "finish\n");
 304 }
 305
 306 static void jsm_tty_set_termios(struct uart_port *port,
 307                                  struct ktermios *termios,
 308                                  struct ktermios *old_termios)
 309 {
 310         unsigned long lock_flags;
 311         struct jsm_channel *channel = (struct jsm_channel *)port;
 312
 313         spin_lock_irqsave(&port->lock, lock_flags);
 314         channel->ch_c_cflag     = termios->c_cflag;
 315         channel->ch_c_iflag     = termios->c_iflag;
 316         channel->ch_c_oflag     = termios->c_oflag;
 317         channel->ch_c_lflag     = termios->c_lflag;
 318         channel->ch_startc      = termios->c_cc[VSTART];
 319         channel->ch_stopc       = termios->c_cc[VSTOP];
 320
 321         channel->ch_bd->bd_ops->param(channel);
 322         jsm_carrier(channel);
 323         spin_unlock_irqrestore(&port->lock, lock_flags);
 324 }
 325
 326 static const char *jsm_tty_type(struct uart_port *port)
 327 {
 328         return "jsm";
 329 }
 330
 331 static void jsm_tty_release_port(struct uart_port *port)
 332 {
 333 }
 334
 335 static int jsm_tty_request_port(struct uart_port *port)
 336 {
 337         return 0;
 338 }
 339
 340 static void jsm_config_port(struct uart_port *port, int flags)
 341 {
 342         port->type = PORT_JSM;
 343 }
 344
 345 static struct uart_ops jsm_ops = {
 346         .tx_empty       = jsm_tty_tx_empty,
 347         .set_mctrl      = jsm_tty_set_mctrl,
 348         .get_mctrl      = jsm_tty_get_mctrl,
 349         .stop_tx        = jsm_tty_stop_tx,
 350         .start_tx       = jsm_tty_start_tx,
 351         .send_xchar     = jsm_tty_send_xchar,
 352         .stop_rx        = jsm_tty_stop_rx,
 353         .enable_ms      = jsm_tty_enable_ms,
 354         .break_ctl      = jsm_tty_break,
 355         .startup        = jsm_tty_open,
 356         .shutdown       = jsm_tty_close,
 357         .set_termios    = jsm_tty_set_termios,
 358         .type           = jsm_tty_type,
 359         .release_port   = jsm_tty_release_port,
 360         .request_port   = jsm_tty_request_port,
 361         .config_port    = jsm_config_port,
 362 };
 363
 364 /*
 365  * jsm_tty_init()
 366  *
 367  * Init the tty subsystem.  Called once per board after board has been
 368  * downloaded and init'ed.
 369  */
 370 int __devinit jsm_tty_init(struct jsm_board *brd)
 371 {
 372         int i;
 373         void __iomem *vaddr;
 374         struct jsm_channel *ch;
 375
 376         if (!brd)
 377                 return -ENXIO;
 378
 379         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 380
 381         /*
 382          * Initialize board structure elements.
 383          */
 384
 385         brd->nasync = brd->maxports;
 386
 387         /*
 388          * Allocate channel memory that might not have been allocated
 389          * when the driver was first loaded.
 390          */
 391         for (i = 0; i < brd->nasync; i++) {
 392                 if (!brd->channels[i]) {
 393
 394                         /*
 395                          * Okay to malloc with GFP_KERNEL, we are not at
 396                          * interrupt context, and there are no locks held.
 397                          */
 398                         brd->channels[i] = kzalloc(sizeof(struct jsm_channel), GFP_KERNEL);
 399                         if (!brd->channels[i]) {
 400                                 jsm_printk(CORE, ERR, &brd->pci_dev,
 401                                         "%s:%d Unable to allocate memory for channel struct\n",
 402                                                          __FILE__, __LINE__);
 403                         }
 404                 }
 405         }
 406
 407         ch = brd->channels[0];
 408         vaddr = brd->re_map_membase;
 409
 410         /* Set up channel variables */
 411         for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
 412
 413                 if (!brd->channels[i])
 414                         continue;
 415
 416                 spin_lock_init(&ch->ch_lock);
 417
 418                 if (brd->bd_uart_offset == 0x200)
 419                         ch->ch_neo_uart =  vaddr + (brd->bd_uart_offset * i);
 420
 421                 ch->ch_bd = brd;
 422                 ch->ch_portnum = i;
 423
 424                 /* .25 second delay */
 425                 ch->ch_close_delay = 250;
 426
 427                 init_waitqueue_head(&ch->ch_flags_wait);
 428         }
 429
 430         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 431         return 0;
 432 }
 433
 434 int jsm_uart_port_init(struct jsm_board *brd)
 435 {
 436         int i, rc;
 437         unsigned int line;
 438         struct jsm_channel *ch;
 439
 440         if (!brd)
 441                 return -ENXIO;
 442
 443         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 444
 445         /*
 446          * Initialize board structure elements.
 447          */
 448
 449         brd->nasync = brd->maxports;
 450
 451         /* Set up channel variables */
 452         for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
 453
 454                 if (!brd->channels[i])
 455                         continue;
 456
 457                 brd->channels[i]->uart_port.irq = brd->irq;
 458                 brd->channels[i]->uart_port.uartclk = 14745600;
 459                 brd->channels[i]->uart_port.type = PORT_JSM;
 460                 brd->channels[i]->uart_port.iotype = UPIO_MEM;
 461                 brd->channels[i]->uart_port.membase = brd->re_map_membase;
 462                 brd->channels[i]->uart_port.fifosize = 16;
 463                 brd->channels[i]->uart_port.ops = &jsm_ops;
 464                 line = find_first_zero_bit(linemap, MAXLINES);
 465                 if (line >= MAXLINES) {
 466                         printk(KERN_INFO "jsm: linemap is full, added device failed\n");
 467                         continue;
 468                 } else
 469                         set_bit(line, linemap);
 470                 brd->channels[i]->uart_port.line = line;
 471                 rc = uart_add_one_port (&jsm_uart_driver, &brd->channels[i]->uart_port);
 472                 if (rc){
 473                         printk(KERN_INFO "jsm: Port %d failed. Aborting...\n", i);
 474                         return rc;
 475                 }
 476                 else
 477                         printk(KERN_INFO "jsm: Port %d added\n", i);
 478         }
 479
 480         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 481         return 0;
 482 }
 483
 484 int jsm_remove_uart_port(struct jsm_board *brd)
 485 {
 486         int i;
 487         struct jsm_channel *ch;
 488
 489         if (!brd)
 490                 return -ENXIO;
 491
 492         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 493
 494         /*
 495          * Initialize board structure elements.
 496          */
 497
 498         brd->nasync = brd->maxports;
 499
 500         /* Set up channel variables */
 501         for (i = 0; i < brd->nasync; i++) {
 502
 503                 if (!brd->channels[i])
 504                         continue;
 505
 506                 ch = brd->channels[i];
 507
 508                 clear_bit(ch->uart_port.line, linemap);
 509                 uart_remove_one_port(&jsm_uart_driver, &brd->channels[i]->uart_port);
 510         }
 511
 512         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 513         return 0;
 514 }
 515
 516 void jsm_input(struct jsm_channel *ch)
 517 {
 518         struct jsm_board *bd;
 519         struct tty_struct *tp;
 520         u32 rmask;
 521         u16 head;
 522         u16 tail;
 523         int data_len;
 524         unsigned long lock_flags;
 525         int len = 0;
 526         int n = 0;
 527         int s = 0;
 528         int i = 0;
 529
 530         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n");
 531
 532         if (!ch)
 533                 return;
 534
 535         tp = ch->uart_port.state->port.tty;
 536
 537         bd = ch->ch_bd;
 538         if(!bd)
 539                 return;
 540
 541         spin_lock_irqsave(&ch->ch_lock, lock_flags);
 542
 543         /*
 544          *Figure the number of characters in the buffer.
 545          *Exit immediately if none.
 546          */
 547
 548         rmask = RQUEUEMASK;
 549
 550         head = ch->ch_r_head & rmask;
 551         tail = ch->ch_r_tail & rmask;
 552
 553         data_len = (head - tail) & rmask;
 554         if (data_len == 0) {
 555                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 556                 return;
 557         }
 558
 559         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n");
 560
 561         /*
 562          *If the device is not open, or CREAD is off, flush
 563          *input data and return immediately.
 564          */
 565         if (!tp ||
 566                 !(tp->termios->c_cflag & CREAD) ) {
 567
 568                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 569                         "input. dropping %d bytes on port %d...\n", data_len, ch->ch_portnum);
 570                 ch->ch_r_head = tail;
 571
 572                 /* Force queue flow control to be released, if needed */
 573                 jsm_check_queue_flow_control(ch);
 574
 575                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 576                 return;
 577         }
 578
 579         /*
 580          * If we are throttled, simply don't read any data.
 581          */
 582         if (ch->ch_flags & CH_STOPI) {
 583                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 584                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 585                         "Port %d throttled, not reading any data. head: %x tail: %x\n",
 586                         ch->ch_portnum, head, tail);
 587                 return;
 588         }
 589
 590         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start 2\n");
 591
 592         if (data_len <= 0) {
 593                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 594                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "jsm_input 1\n");
 595                 return;
 596         }
 597
 598         len = tty_buffer_request_room(tp, data_len);
 599         n = len;
 600
 601         /*
 602          * n now contains the most amount of data we can copy,
 603          * bounded either by the flip buffer size or the amount
 604          * of data the card actually has pending...
 605          */
 606         while (n) {
 607                 s = ((head >= tail) ? head : RQUEUESIZE) - tail;
 608                 s = min(s, n);
 609
 610                 if (s <= 0)
 611                         break;
 612
 613                         /*
 614                          * If conditions are such that ld needs to see all
 615                          * UART errors, we will have to walk each character
 616                          * and error byte and send them to the buffer one at
 617                          * a time.
 618                          */
 619
 620                 if (I_PARMRK(tp) || I_BRKINT(tp) || I_INPCK(tp)) {
 621                         for (i = 0; i < s; i++) {
 622                                 /*
 623                                  * Give the Linux ld the flags in the
 624                                  * format it likes.
 625                                  */
 626                                 if (*(ch->ch_equeue +tail +i) & UART_LSR_BI)
 627                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i),  TTY_BREAK);
 628                                 else if (*(ch->ch_equeue +tail +i) & UART_LSR_PE)
 629                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_PARITY);
 630                                 else if (*(ch->ch_equeue +tail +i) & UART_LSR_FE)
 631                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_FRAME);
 632                                 else
 633                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_NORMAL);
 634                         }
 635                 } else {
 636                         tty_insert_flip_string(tp, ch->ch_rqueue + tail, s) ;
 637                 }
 638                 tail += s;
 639                 n -= s;
 640                 /* Flip queue if needed */
 641                 tail &= rmask;
 642         }
 643
 644         ch->ch_r_tail = tail & rmask;
 645         ch->ch_e_tail = tail & rmask;
 646         jsm_check_queue_flow_control(ch);
 647         spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 648
 649         /* Tell the tty layer its okay to "eat" the data now */
 650         tty_flip_buffer_push(tp);
 651
 652         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "finish\n");
 653 }
 654
 655 static void jsm_carrier(struct jsm_channel *ch)
 656 {
 657         struct jsm_board *bd;
 658
 659         int virt_carrier = 0;
 660         int phys_carrier = 0;
 661
 662         jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev, "start\n");
 663         if (!ch)
 664                 return;
 665
 666         bd = ch->ch_bd;
 667
 668         if (!bd)
 669                 return;
 670
 671         if (ch->ch_mistat & UART_MSR_DCD) {
 672                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 673                         "mistat: %x D_CD: %x\n", ch->ch_mistat, ch->ch_mistat & UART_MSR_DCD);
 674                 phys_carrier = 1;
 675         }
 676
 677         if (ch->ch_c_cflag & CLOCAL)
 678                 virt_carrier = 1;
 679
 680         jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 681                 "DCD: physical: %d virt: %d\n", phys_carrier, virt_carrier);
 682
 683         /*
 684          * Test for a VIRTUAL carrier transition to HIGH.
 685          */
 686         if (((ch->ch_flags & CH_FCAR) == 0) && (virt_carrier == 1)) {
 687
 688                 /*
 689                  * When carrier rises, wake any threads waiting
 690                  * for carrier in the open routine.
 691                  */
 692
 693                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 694                         "carrier: virt DCD rose\n");
 695
 696                 if (waitqueue_active(&(ch->ch_flags_wait)))
 697                         wake_up_interruptible(&ch->ch_flags_wait);
 698         }
 699
 700         /*
 701          * Test for a PHYSICAL carrier transition to HIGH.
 702          */
 703         if (((ch->ch_flags & CH_CD) == 0) && (phys_carrier == 1)) {
 704
 705                 /*
 706                  * When carrier rises, wake any threads waiting
 707                  * for carrier in the open routine.
 708                  */
 709
 710                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 711                         "carrier: physical DCD rose\n");
 712
 713                 if (waitqueue_active(&(ch->ch_flags_wait)))
 714                         wake_up_interruptible(&ch->ch_flags_wait);
 715         }
 716
 717         /*
 718          *  Test for a PHYSICAL transition to low, so long as we aren't
 719          *  currently ignoring physical transitions (which is what "virtual
 720          *  carrier" indicates).
 721          *
 722          *  The transition of the virtual carrier to low really doesn't
 723          *  matter... it really only means "ignore carrier state", not
 724          *  "make pretend that carrier is there".
 725          */
 726         if ((virt_carrier == 0) && ((ch->ch_flags & CH_CD) != 0)
 727                         && (phys_carrier == 0)) {
 728                 /*
 729                  *      When carrier drops:
 730                  *
 731                  *      Drop carrier on all open units.
 732                  *
 733                  *      Flush queues, waking up any task waiting in the
 734                  *      line discipline.
 735                  *
 736                  *      Send a hangup to the control terminal.
 737                  *
 738                  *      Enable all select calls.
 739                  */
 740                 if (waitqueue_active(&(ch->ch_flags_wait)))
 741                         wake_up_interruptible(&ch->ch_flags_wait);
 742         }
 743
 744         /*
 745          *  Make sure that our cached values reflect the current reality.
 746          */
 747         if (virt_carrier == 1)
 748                 ch->ch_flags |= CH_FCAR;
 749         else
 750                 ch->ch_flags &= ~CH_FCAR;
 751
 752         if (phys_carrier == 1)
 753                 ch->ch_flags |= CH_CD;
 754         else
 755                 ch->ch_flags &= ~CH_CD;
 756 }
 757
 758
 759 void jsm_check_queue_flow_control(struct jsm_channel *ch)
 760 {
 761         struct board_ops *bd_ops = ch->ch_bd->bd_ops;
 762         int qleft;
 763
 764         /* Store how much space we have left in the queue */
 765         if ((qleft = ch->ch_r_tail - ch->ch_r_head - 1) < 0)
 766                 qleft += RQUEUEMASK + 1;
 767
 768         /*
 769          * Check to see if we should enforce flow control on our queue because
 770          * the ld (or user) isn't reading data out of our queue fast enuf.
 771          *
 772          * NOTE: This is done based on what the current flow control of the
 773          * port is set for.
 774          *
 775          * 1) HWFLOW (RTS) - Turn off the UART's Receive interrupt.
 776          *      This will cause the UART's FIFO to back up, and force
 777          *      the RTS signal to be dropped.
 778          * 2) SWFLOW (IXOFF) - Keep trying to send a stop character to
 779          *      the other side, in hopes it will stop sending data to us.
 780          * 3) NONE - Nothing we can do.  We will simply drop any extra data
 781          *      that gets sent into us when the queue fills up.
 782          */
 783         if (qleft < 256) {
 784                 /* HWFLOW */
 785                 if (ch->ch_c_cflag & CRTSCTS) {
 786                         if(!(ch->ch_flags & CH_RECEIVER_OFF)) {
 787                                 bd_ops->disable_receiver(ch);
 788                                 ch->ch_flags |= (CH_RECEIVER_OFF);
 789                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 790                                         "Internal queue hit hilevel mark (%d)! Turning off interrupts.\n",
 791                                         qleft);
 792                         }
 793                 }
 794                 /* SWFLOW */
 795                 else if (ch->ch_c_iflag & IXOFF) {
 796                         if (ch->ch_stops_sent <= MAX_STOPS_SENT) {
 797                                 bd_ops->send_stop_character(ch);
 798                                 ch->ch_stops_sent++;
 799                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 800                                         "Sending stop char! Times sent: %x\n", ch->ch_stops_sent);
 801                         }
 802                 }
 803         }
 804
 805         /*
 806          * Check to see if we should unenforce flow control because
 807          * ld (or user) finally read enuf data out of our queue.
 808          *
 809          * NOTE: This is done based on what the current flow control of the
 810          * port is set for.
 811          *
 812          * 1) HWFLOW (RTS) - Turn back on the UART's Receive interrupt.
 813          *      This will cause the UART's FIFO to raise RTS back up,
 814          *      which will allow the other side to start sending data again.
 815          * 2) SWFLOW (IXOFF) - Send a start character to
 816          *      the other side, so it will start sending data to us again.
 817          * 3) NONE - Do nothing. Since we didn't do anything to turn off the
 818          *      other side, we don't need to do anything now.
 819          */
 820         if (qleft > (RQUEUESIZE / 2)) {
 821                 /* HWFLOW */
 822                 if (ch->ch_c_cflag & CRTSCTS) {
 823                         if (ch->ch_flags & CH_RECEIVER_OFF) {
 824                                 bd_ops->enable_receiver(ch);
 825                                 ch->ch_flags &= ~(CH_RECEIVER_OFF);
 826                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 827                                         "Internal queue hit lowlevel mark (%d)! Turning on interrupts.\n",
 828                                         qleft);
 829                         }
 830                 }
 831                 /* SWFLOW */
 832                 else if (ch->ch_c_iflag & IXOFF && ch->ch_stops_sent) {
 833                         ch->ch_stops_sent = 0;
 834                         bd_ops->send_start_character(ch);
 835                         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "Sending start char!\n");
 836                 }
 837         }
 838 }
 839
 840 /*
 841  * jsm_tty_write()
 842  *
 843  * Take data from the user or kernel and send it out to the FEP.
 844  * In here exists all the Transparent Print magic as well.
 845  */
 846 int jsm_tty_write(struct uart_port *port)
 847 {
 848         int bufcount;
 849         int data_count = 0,data_count1 =0;
 850         u16 head;
 851         u16 tail;
 852         u16 tmask;
 853         u32 remain;
 854         int temp_tail = port->state->xmit.tail;
 855         struct jsm_channel *channel = (struct jsm_channel *)port;
 856
 857         tmask = WQUEUEMASK;
 858         head = (channel->ch_w_head) & tmask;
 859         tail = (channel->ch_w_tail) & tmask;
 860
 861         if ((bufcount = tail - head - 1) < 0)
 862                 bufcount += WQUEUESIZE;
 863
 864         bufcount = min(bufcount, 56);
 865         remain = WQUEUESIZE - head;
 866
 867         data_count = 0;
 868         if (bufcount >= remain) {
 869                 bufcount -= remain;
 870                 while ((port->state->xmit.head != temp_tail) &&
 871                 (data_count < remain)) {
 872                         channel->ch_wqueue[head++] =
 873                         port->state->xmit.buf[temp_tail];
 874
 875                         temp_tail++;
 876                         temp_tail &= (UART_XMIT_SIZE - 1);
 877                         data_count++;
 878                 }
 879                 if (data_count == remain) head = 0;
 880         }
 881
 882         data_count1 = 0;
 883         if (bufcount > 0) {
 884                 remain = bufcount;
 885                 while ((port->state->xmit.head != temp_tail) &&
 886                         (data_count1 < remain)) {
 887                         channel->ch_wqueue[head++] =
 888                                 port->state->xmit.buf[temp_tail];
 889
 890                         temp_tail++;
 891                         temp_tail &= (UART_XMIT_SIZE - 1);
 892                         data_count1++;
 893
 894                 }
 895         }
 896
 897         port->state->xmit.tail = temp_tail;
 898
 899         data_count += data_count1;
 900         if (data_count) {
 901                 head &= tmask;
 902                 channel->ch_w_head = head;
 903         }
 904
 905         if (data_count) {
 906                 channel->ch_bd->bd_ops->copy_data_from_queue_to_uart(channel);
 907         }
 908
 909         return data_count;
 910 }