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->state->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->state->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->state->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         /* Turn off UART interrupts for this port */
 300         channel->ch_bd->bd_ops->uart_off(channel);
 301
 302         jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev, "finish\n");
 303 }
 304
 305 static void jsm_tty_set_termios(struct uart_port *port,
 306                                  struct ktermios *termios,
 307                                  struct ktermios *old_termios)
 308 {
 309         unsigned long lock_flags;
 310         struct jsm_channel *channel = (struct jsm_channel *)port;
 311
 312         spin_lock_irqsave(&port->lock, lock_flags);
 313         channel->ch_c_cflag     = termios->c_cflag;
 314         channel->ch_c_iflag     = termios->c_iflag;
 315         channel->ch_c_oflag     = termios->c_oflag;
 316         channel->ch_c_lflag     = termios->c_lflag;
 317         channel->ch_startc      = termios->c_cc[VSTART];
 318         channel->ch_stopc       = termios->c_cc[VSTOP];
 319
 320         channel->ch_bd->bd_ops->param(channel);
 321         jsm_carrier(channel);
 322         spin_unlock_irqrestore(&port->lock, lock_flags);
 323 }
 324
 325 static const char *jsm_tty_type(struct uart_port *port)
 326 {
 327         return "jsm";
 328 }
 329
 330 static void jsm_tty_release_port(struct uart_port *port)
 331 {
 332 }
 333
 334 static int jsm_tty_request_port(struct uart_port *port)
 335 {
 336         return 0;
 337 }
 338
 339 static void jsm_config_port(struct uart_port *port, int flags)
 340 {
 341         port->type = PORT_JSM;
 342 }
 343
 344 static struct uart_ops jsm_ops = {
 345         .tx_empty       = jsm_tty_tx_empty,
 346         .set_mctrl      = jsm_tty_set_mctrl,
 347         .get_mctrl      = jsm_tty_get_mctrl,
 348         .stop_tx        = jsm_tty_stop_tx,
 349         .start_tx       = jsm_tty_start_tx,
 350         .send_xchar     = jsm_tty_send_xchar,
 351         .stop_rx        = jsm_tty_stop_rx,
 352         .enable_ms      = jsm_tty_enable_ms,
 353         .break_ctl      = jsm_tty_break,
 354         .startup        = jsm_tty_open,
 355         .shutdown       = jsm_tty_close,
 356         .set_termios    = jsm_tty_set_termios,
 357         .type           = jsm_tty_type,
 358         .release_port   = jsm_tty_release_port,
 359         .request_port   = jsm_tty_request_port,
 360         .config_port    = jsm_config_port,
 361 };
 362
 363 /*
 364  * jsm_tty_init()
 365  *
 366  * Init the tty subsystem.  Called once per board after board has been
 367  * downloaded and init'ed.
 368  */
 369 int __devinit jsm_tty_init(struct jsm_board *brd)
 370 {
 371         int i;
 372         void __iomem *vaddr;
 373         struct jsm_channel *ch;
 374
 375         if (!brd)
 376                 return -ENXIO;
 377
 378         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 379
 380         /*
 381          * Initialize board structure elements.
 382          */
 383
 384         brd->nasync = brd->maxports;
 385
 386         /*
 387          * Allocate channel memory that might not have been allocated
 388          * when the driver was first loaded.
 389          */
 390         for (i = 0; i < brd->nasync; i++) {
 391                 if (!brd->channels[i]) {
 392
 393                         /*
 394                          * Okay to malloc with GFP_KERNEL, we are not at
 395                          * interrupt context, and there are no locks held.
 396                          */
 397                         brd->channels[i] = kzalloc(sizeof(struct jsm_channel), GFP_KERNEL);
 398                         if (!brd->channels[i]) {
 399                                 jsm_printk(CORE, ERR, &brd->pci_dev,
 400                                         "%s:%d Unable to allocate memory for channel struct\n",
 401                                                          __FILE__, __LINE__);
 402                         }
 403                 }
 404         }
 405
 406         ch = brd->channels[0];
 407         vaddr = brd->re_map_membase;
 408
 409         /* Set up channel variables */
 410         for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
 411
 412                 if (!brd->channels[i])
 413                         continue;
 414
 415                 spin_lock_init(&ch->ch_lock);
 416
 417                 if (brd->bd_uart_offset == 0x200)
 418                         ch->ch_neo_uart =  vaddr + (brd->bd_uart_offset * i);
 419
 420                 ch->ch_bd = brd;
 421                 ch->ch_portnum = i;
 422
 423                 /* .25 second delay */
 424                 ch->ch_close_delay = 250;
 425
 426                 init_waitqueue_head(&ch->ch_flags_wait);
 427         }
 428
 429         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 430         return 0;
 431 }
 432
 433 int jsm_uart_port_init(struct jsm_board *brd)
 434 {
 435         int i, rc;
 436         unsigned int line;
 437         struct jsm_channel *ch;
 438
 439         if (!brd)
 440                 return -ENXIO;
 441
 442         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 443
 444         /*
 445          * Initialize board structure elements.
 446          */
 447
 448         brd->nasync = brd->maxports;
 449
 450         /* Set up channel variables */
 451         for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
 452
 453                 if (!brd->channels[i])
 454                         continue;
 455
 456                 brd->channels[i]->uart_port.irq = brd->irq;
 457                 brd->channels[i]->uart_port.uartclk = 14745600;
 458                 brd->channels[i]->uart_port.type = PORT_JSM;
 459                 brd->channels[i]->uart_port.iotype = UPIO_MEM;
 460                 brd->channels[i]->uart_port.membase = brd->re_map_membase;
 461                 brd->channels[i]->uart_port.fifosize = 16;
 462                 brd->channels[i]->uart_port.ops = &jsm_ops;
 463                 line = find_first_zero_bit(linemap, MAXLINES);
 464                 if (line >= MAXLINES) {
 465                         printk(KERN_INFO "jsm: linemap is full, added device failed\n");
 466                         continue;
 467                 } else
 468                         set_bit(line, linemap);
 469                 brd->channels[i]->uart_port.line = line;
 470                 rc = uart_add_one_port (&jsm_uart_driver, &brd->channels[i]->uart_port);
 471                 if (rc){
 472                         printk(KERN_INFO "jsm: Port %d failed. Aborting...\n", i);
 473                         return rc;
 474                 }
 475                 else
 476                         printk(KERN_INFO "jsm: Port %d added\n", i);
 477         }
 478
 479         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 480         return 0;
 481 }
 482
 483 int jsm_remove_uart_port(struct jsm_board *brd)
 484 {
 485         int i;
 486         struct jsm_channel *ch;
 487
 488         if (!brd)
 489                 return -ENXIO;
 490
 491         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 492
 493         /*
 494          * Initialize board structure elements.
 495          */
 496
 497         brd->nasync = brd->maxports;
 498
 499         /* Set up channel variables */
 500         for (i = 0; i < brd->nasync; i++) {
 501
 502                 if (!brd->channels[i])
 503                         continue;
 504
 505                 ch = brd->channels[i];
 506
 507                 clear_bit(ch->uart_port.line, linemap);
 508                 uart_remove_one_port(&jsm_uart_driver, &brd->channels[i]->uart_port);
 509         }
 510
 511         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 512         return 0;
 513 }
 514
 515 void jsm_input(struct jsm_channel *ch)
 516 {
 517         struct jsm_board *bd;
 518         struct tty_struct *tp;
 519         u32 rmask;
 520         u16 head;
 521         u16 tail;
 522         int data_len;
 523         unsigned long lock_flags;
 524         int len = 0;
 525         int n = 0;
 526         int s = 0;
 527         int i = 0;
 528
 529         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n");
 530
 531         if (!ch)
 532                 return;
 533
 534         tp = ch->uart_port.state->port.tty;
 535
 536         bd = ch->ch_bd;
 537         if(!bd)
 538                 return;
 539
 540         spin_lock_irqsave(&ch->ch_lock, lock_flags);
 541
 542         /*
 543          *Figure the number of characters in the buffer.
 544          *Exit immediately if none.
 545          */
 546
 547         rmask = RQUEUEMASK;
 548
 549         head = ch->ch_r_head & rmask;
 550         tail = ch->ch_r_tail & rmask;
 551
 552         data_len = (head - tail) & rmask;
 553         if (data_len == 0) {
 554                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 555                 return;
 556         }
 557
 558         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n");
 559
 560         /*
 561          *If the device is not open, or CREAD is off, flush
 562          *input data and return immediately.
 563          */
 564         if (!tp ||
 565                 !(tp->termios->c_cflag & CREAD) ) {
 566
 567                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 568                         "input. dropping %d bytes on port %d...\n", data_len, ch->ch_portnum);
 569                 ch->ch_r_head = tail;
 570
 571                 /* Force queue flow control to be released, if needed */
 572                 jsm_check_queue_flow_control(ch);
 573
 574                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 575                 return;
 576         }
 577
 578         /*
 579          * If we are throttled, simply don't read any data.
 580          */
 581         if (ch->ch_flags & CH_STOPI) {
 582                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 583                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 584                         "Port %d throttled, not reading any data. head: %x tail: %x\n",
 585                         ch->ch_portnum, head, tail);
 586                 return;
 587         }
 588
 589         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start 2\n");
 590
 591         if (data_len <= 0) {
 592                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 593                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "jsm_input 1\n");
 594                 return;
 595         }
 596
 597         len = tty_buffer_request_room(tp, data_len);
 598         n = len;
 599
 600         /*
 601          * n now contains the most amount of data we can copy,
 602          * bounded either by the flip buffer size or the amount
 603          * of data the card actually has pending...
 604          */
 605         while (n) {
 606                 s = ((head >= tail) ? head : RQUEUESIZE) - tail;
 607                 s = min(s, n);
 608
 609                 if (s <= 0)
 610                         break;
 611
 612                         /*
 613                          * If conditions are such that ld needs to see all
 614                          * UART errors, we will have to walk each character
 615                          * and error byte and send them to the buffer one at
 616                          * a time.
 617                          */
 618
 619                 if (I_PARMRK(tp) || I_BRKINT(tp) || I_INPCK(tp)) {
 620                         for (i = 0; i < s; i++) {
 621                                 /*
 622                                  * Give the Linux ld the flags in the
 623                                  * format it likes.
 624                                  */
 625                                 if (*(ch->ch_equeue +tail +i) & UART_LSR_BI)
 626                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i),  TTY_BREAK);
 627                                 else if (*(ch->ch_equeue +tail +i) & UART_LSR_PE)
 628                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_PARITY);
 629                                 else if (*(ch->ch_equeue +tail +i) & UART_LSR_FE)
 630                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_FRAME);
 631                                 else
 632                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_NORMAL);
 633                         }
 634                 } else {
 635                         tty_insert_flip_string(tp, ch->ch_rqueue + tail, s) ;
 636                 }
 637                 tail += s;
 638                 n -= s;
 639                 /* Flip queue if needed */
 640                 tail &= rmask;
 641         }
 642
 643         ch->ch_r_tail = tail & rmask;
 644         ch->ch_e_tail = tail & rmask;
 645         jsm_check_queue_flow_control(ch);
 646         spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 647
 648         /* Tell the tty layer its okay to "eat" the data now */
 649         tty_flip_buffer_push(tp);
 650
 651         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "finish\n");
 652 }
 653
 654 static void jsm_carrier(struct jsm_channel *ch)
 655 {
 656         struct jsm_board *bd;
 657
 658         int virt_carrier = 0;
 659         int phys_carrier = 0;
 660
 661         jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev, "start\n");
 662         if (!ch)
 663                 return;
 664
 665         bd = ch->ch_bd;
 666
 667         if (!bd)
 668                 return;
 669
 670         if (ch->ch_mistat & UART_MSR_DCD) {
 671                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 672                         "mistat: %x D_CD: %x\n", ch->ch_mistat, ch->ch_mistat & UART_MSR_DCD);
 673                 phys_carrier = 1;
 674         }
 675
 676         if (ch->ch_c_cflag & CLOCAL)
 677                 virt_carrier = 1;
 678
 679         jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 680                 "DCD: physical: %d virt: %d\n", phys_carrier, virt_carrier);
 681
 682         /*
 683          * Test for a VIRTUAL carrier transition to HIGH.
 684          */
 685         if (((ch->ch_flags & CH_FCAR) == 0) && (virt_carrier == 1)) {
 686
 687                 /*
 688                  * When carrier rises, wake any threads waiting
 689                  * for carrier in the open routine.
 690                  */
 691
 692                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 693                         "carrier: virt DCD rose\n");
 694
 695                 if (waitqueue_active(&(ch->ch_flags_wait)))
 696                         wake_up_interruptible(&ch->ch_flags_wait);
 697         }
 698
 699         /*
 700          * Test for a PHYSICAL carrier transition to HIGH.
 701          */
 702         if (((ch->ch_flags & CH_CD) == 0) && (phys_carrier == 1)) {
 703
 704                 /*
 705                  * When carrier rises, wake any threads waiting
 706                  * for carrier in the open routine.
 707                  */
 708
 709                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 710                         "carrier: physical DCD rose\n");
 711
 712                 if (waitqueue_active(&(ch->ch_flags_wait)))
 713                         wake_up_interruptible(&ch->ch_flags_wait);
 714         }
 715
 716         /*
 717          *  Test for a PHYSICAL transition to low, so long as we aren't
 718          *  currently ignoring physical transitions (which is what "virtual
 719          *  carrier" indicates).
 720          *
 721          *  The transition of the virtual carrier to low really doesn't
 722          *  matter... it really only means "ignore carrier state", not
 723          *  "make pretend that carrier is there".
 724          */
 725         if ((virt_carrier == 0) && ((ch->ch_flags & CH_CD) != 0)
 726                         && (phys_carrier == 0)) {
 727                 /*
 728                  *      When carrier drops:
 729                  *
 730                  *      Drop carrier on all open units.
 731                  *
 732                  *      Flush queues, waking up any task waiting in the
 733                  *      line discipline.
 734                  *
 735                  *      Send a hangup to the control terminal.
 736                  *
 737                  *      Enable all select calls.
 738                  */
 739                 if (waitqueue_active(&(ch->ch_flags_wait)))
 740                         wake_up_interruptible(&ch->ch_flags_wait);
 741         }
 742
 743         /*
 744          *  Make sure that our cached values reflect the current reality.
 745          */
 746         if (virt_carrier == 1)
 747                 ch->ch_flags |= CH_FCAR;
 748         else
 749                 ch->ch_flags &= ~CH_FCAR;
 750
 751         if (phys_carrier == 1)
 752                 ch->ch_flags |= CH_CD;
 753         else
 754                 ch->ch_flags &= ~CH_CD;
 755 }
 756
 757
 758 void jsm_check_queue_flow_control(struct jsm_channel *ch)
 759 {
 760         struct board_ops *bd_ops = ch->ch_bd->bd_ops;
 761         int qleft;
 762
 763         /* Store how much space we have left in the queue */
 764         if ((qleft = ch->ch_r_tail - ch->ch_r_head - 1) < 0)
 765                 qleft += RQUEUEMASK + 1;
 766
 767         /*
 768          * Check to see if we should enforce flow control on our queue because
 769          * the ld (or user) isn't reading data out of our queue fast enuf.
 770          *
 771          * NOTE: This is done based on what the current flow control of the
 772          * port is set for.
 773          *
 774          * 1) HWFLOW (RTS) - Turn off the UART's Receive interrupt.
 775          *      This will cause the UART's FIFO to back up, and force
 776          *      the RTS signal to be dropped.
 777          * 2) SWFLOW (IXOFF) - Keep trying to send a stop character to
 778          *      the other side, in hopes it will stop sending data to us.
 779          * 3) NONE - Nothing we can do.  We will simply drop any extra data
 780          *      that gets sent into us when the queue fills up.
 781          */
 782         if (qleft < 256) {
 783                 /* HWFLOW */
 784                 if (ch->ch_c_cflag & CRTSCTS) {
 785                         if(!(ch->ch_flags & CH_RECEIVER_OFF)) {
 786                                 bd_ops->disable_receiver(ch);
 787                                 ch->ch_flags |= (CH_RECEIVER_OFF);
 788                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 789                                         "Internal queue hit hilevel mark (%d)! Turning off interrupts.\n",
 790                                         qleft);
 791                         }
 792                 }
 793                 /* SWFLOW */
 794                 else if (ch->ch_c_iflag & IXOFF) {
 795                         if (ch->ch_stops_sent <= MAX_STOPS_SENT) {
 796                                 bd_ops->send_stop_character(ch);
 797                                 ch->ch_stops_sent++;
 798                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 799                                         "Sending stop char! Times sent: %x\n", ch->ch_stops_sent);
 800                         }
 801                 }
 802         }
 803
 804         /*
 805          * Check to see if we should unenforce flow control because
 806          * ld (or user) finally read enuf data out of our queue.
 807          *
 808          * NOTE: This is done based on what the current flow control of the
 809          * port is set for.
 810          *
 811          * 1) HWFLOW (RTS) - Turn back on the UART's Receive interrupt.
 812          *      This will cause the UART's FIFO to raise RTS back up,
 813          *      which will allow the other side to start sending data again.
 814          * 2) SWFLOW (IXOFF) - Send a start character to
 815          *      the other side, so it will start sending data to us again.
 816          * 3) NONE - Do nothing. Since we didn't do anything to turn off the
 817          *      other side, we don't need to do anything now.
 818          */
 819         if (qleft > (RQUEUESIZE / 2)) {
 820                 /* HWFLOW */
 821                 if (ch->ch_c_cflag & CRTSCTS) {
 822                         if (ch->ch_flags & CH_RECEIVER_OFF) {
 823                                 bd_ops->enable_receiver(ch);
 824                                 ch->ch_flags &= ~(CH_RECEIVER_OFF);
 825                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 826                                         "Internal queue hit lowlevel mark (%d)! Turning on interrupts.\n",
 827                                         qleft);
 828                         }
 829                 }
 830                 /* SWFLOW */
 831                 else if (ch->ch_c_iflag & IXOFF && ch->ch_stops_sent) {
 832                         ch->ch_stops_sent = 0;
 833                         bd_ops->send_start_character(ch);
 834                         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "Sending start char!\n");
 835                 }
 836         }
 837 }
 838
 839 /*
 840  * jsm_tty_write()
 841  *
 842  * Take data from the user or kernel and send it out to the FEP.
 843  * In here exists all the Transparent Print magic as well.
 844  */
 845 int jsm_tty_write(struct uart_port *port)
 846 {
 847         int bufcount;
 848         int data_count = 0,data_count1 =0;
 849         u16 head;
 850         u16 tail;
 851         u16 tmask;
 852         u32 remain;
 853         int temp_tail = port->state->xmit.tail;
 854         struct jsm_channel *channel = (struct jsm_channel *)port;
 855
 856         tmask = WQUEUEMASK;
 857         head = (channel->ch_w_head) & tmask;
 858         tail = (channel->ch_w_tail) & tmask;
 859
 860         if ((bufcount = tail - head - 1) < 0)
 861                 bufcount += WQUEUESIZE;
 862
 863         bufcount = min(bufcount, 56);
 864         remain = WQUEUESIZE - head;
 865
 866         data_count = 0;
 867         if (bufcount >= remain) {
 868                 bufcount -= remain;
 869                 while ((port->state->xmit.head != temp_tail) &&
 870                 (data_count < remain)) {
 871                         channel->ch_wqueue[head++] =
 872                         port->state->xmit.buf[temp_tail];
 873
 874                         temp_tail++;
 875                         temp_tail &= (UART_XMIT_SIZE - 1);
 876                         data_count++;
 877                 }
 878                 if (data_count == remain) head = 0;
 879         }
 880
 881         data_count1 = 0;
 882         if (bufcount > 0) {
 883                 remain = bufcount;
 884                 while ((port->state->xmit.head != temp_tail) &&
 885                         (data_count1 < remain)) {
 886                         channel->ch_wqueue[head++] =
 887                                 port->state->xmit.buf[temp_tail];
 888
 889                         temp_tail++;
 890                         temp_tail &= (UART_XMIT_SIZE - 1);
 891                         data_count1++;
 892
 893                 }
 894         }
 895
 896         port->state->xmit.tail = temp_tail;
 897
 898         data_count += data_count1;
 899         if (data_count) {
 900                 head &= tmask;
 901                 channel->ch_w_head = head;
 902         }
 903
 904         if (data_count) {
 905                 channel->ch_bd->bd_ops->copy_data_from_queue_to_uart(channel);
 906         }
 907
 908         return data_count;
 909 }