drivers/serial/jsm/jsm_tty.c

   1 /************************************************************************
   2  * Copyright 2003 Digi International (www.digi.com)
   3  *
   4  * Copyright (C) 2004 IBM Corporation. All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2, or (at your option)
   9  * any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED; without even the
  13  * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  14  * PURPOSE.  See the GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 * Temple Place - Suite 330, Boston,
  19  * MA  02111-1307, USA.
  20  *
  21  * Contact Information:
  22  * Scott H Kilau <Scott_Kilau@digi.com>
  23  * Ananda Venkatarman <mansarov@us.ibm.com>
  24  * Modifications:
  25  * 01/19/06:    changed jsm_input routine to use the dynamically allocated
  26  *              tty_buffer changes. Contributors: Scott Kilau and Ananda V.
  27  ***********************************************************************/
  28 #include <linux/tty.h>
  29 #include <linux/tty_flip.h>
  30 #include <linux/serial_reg.h>
  31 #include <linux/delay.h>        /* For udelay */
  32 #include <linux/pci.h>
  33
  34 #include "jsm.h"
  35
  36 static void jsm_carrier(struct jsm_channel *ch);
  37
  38 static inline int jsm_get_mstat(struct jsm_channel *ch)
  39 {
  40         unsigned char mstat;
  41         unsigned result;
  42
  43         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "start\n");
  44
  45         mstat = (ch->ch_mostat | ch->ch_mistat);
  46
  47         result = 0;
  48
  49         if (mstat & UART_MCR_DTR)
  50                 result |= TIOCM_DTR;
  51         if (mstat & UART_MCR_RTS)
  52                 result |= TIOCM_RTS;
  53         if (mstat & UART_MSR_CTS)
  54                 result |= TIOCM_CTS;
  55         if (mstat & UART_MSR_DSR)
  56                 result |= TIOCM_DSR;
  57         if (mstat & UART_MSR_RI)
  58                 result |= TIOCM_RI;
  59         if (mstat & UART_MSR_DCD)
  60                 result |= TIOCM_CD;
  61
  62         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "finish\n");
  63         return result;
  64 }
  65
  66 static unsigned int jsm_tty_tx_empty(struct uart_port *port)
  67 {
  68         return TIOCSER_TEMT;
  69 }
  70
  71 /*
  72  * Return modem signals to ld.
  73  */
  74 static unsigned int jsm_tty_get_mctrl(struct uart_port *port)
  75 {
  76         int result;
  77         struct jsm_channel *channel = (struct jsm_channel *)port;
  78
  79         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
  80
  81         result = jsm_get_mstat(channel);
  82
  83         if (result < 0)
  84                 return -ENXIO;
  85
  86         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
  87
  88         return result;
  89 }
  90
  91 /*
  92  * jsm_set_modem_info()
  93  *
  94  * Set modem signals, called by ld.
  95  */
  96 static void jsm_tty_set_mctrl(struct uart_port *port, unsigned int mctrl)
  97 {
  98         struct jsm_channel *channel = (struct jsm_channel *)port;
  99
 100         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
 101
 102         if (mctrl & TIOCM_RTS)
 103                 channel->ch_mostat |= UART_MCR_RTS;
 104         else
 105                 channel->ch_mostat &= ~UART_MCR_RTS;
 106
 107         if (mctrl & TIOCM_DTR)
 108                 channel->ch_mostat |= UART_MCR_DTR;
 109         else
 110                 channel->ch_mostat &= ~UART_MCR_DTR;
 111
 112         channel->ch_bd->bd_ops->assert_modem_signals(channel);
 113
 114         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
 115         udelay(10);
 116 }
 117
 118 static void jsm_tty_start_tx(struct uart_port *port)
 119 {
 120         struct jsm_channel *channel = (struct jsm_channel *)port;
 121
 122         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
 123
 124         channel->ch_flags &= ~(CH_STOP);
 125         jsm_tty_write(port);
 126
 127         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
 128 }
 129
 130 static void jsm_tty_stop_tx(struct uart_port *port)
 131 {
 132         struct jsm_channel *channel = (struct jsm_channel *)port;
 133
 134         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
 135
 136         channel->ch_flags |= (CH_STOP);
 137
 138         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
 139 }
 140
 141 static void jsm_tty_send_xchar(struct uart_port *port, char ch)
 142 {
 143         unsigned long lock_flags;
 144         struct jsm_channel *channel = (struct jsm_channel *)port;
 145         struct ktermios *termios;
 146
 147         spin_lock_irqsave(&port->lock, lock_flags);
 148         termios = port->info->tty->termios;
 149         if (ch == termios->c_cc[VSTART])
 150                 channel->ch_bd->bd_ops->send_start_character(channel);
 151
 152         if (ch == termios->c_cc[VSTOP])
 153                 channel->ch_bd->bd_ops->send_stop_character(channel);
 154         spin_unlock_irqrestore(&port->lock, lock_flags);
 155 }
 156
 157 static void jsm_tty_stop_rx(struct uart_port *port)
 158 {
 159         struct jsm_channel *channel = (struct jsm_channel *)port;
 160
 161         channel->ch_bd->bd_ops->disable_receiver(channel);
 162 }
 163
 164 static void jsm_tty_break(struct uart_port *port, int break_state)
 165 {
 166         unsigned long lock_flags;
 167         struct jsm_channel *channel = (struct jsm_channel *)port;
 168
 169         spin_lock_irqsave(&port->lock, lock_flags);
 170         if (break_state == -1)
 171                 channel->ch_bd->bd_ops->send_break(channel);
 172         else
 173                 channel->ch_bd->bd_ops->clear_break(channel, 0);
 174
 175         spin_unlock_irqrestore(&port->lock, lock_flags);
 176 }
 177
 178 static int jsm_tty_open(struct uart_port *port)
 179 {
 180         struct jsm_board *brd;
 181         int rc = 0;
 182         struct jsm_channel *channel = (struct jsm_channel *)port;
 183         struct ktermios *termios;
 184
 185         /* Get board pointer from our array of majors we have allocated */
 186         brd = channel->ch_bd;
 187
 188         /*
 189          * Allocate channel buffers for read/write/error.
 190          * Set flag, so we don't get trounced on.
 191          */
 192         channel->ch_flags |= (CH_OPENING);
 193
 194         /* Drop locks, as malloc with GFP_KERNEL can sleep */
 195
 196         if (!channel->ch_rqueue) {
 197                 channel->ch_rqueue = (u8 *) kmalloc(RQUEUESIZE, GFP_KERNEL);
 198                 if (!channel->ch_rqueue) {
 199                         jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
 200                                 "unable to allocate read queue buf");
 201                         return -ENOMEM;
 202                 }
 203                 memset(channel->ch_rqueue, 0, RQUEUESIZE);
 204         }
 205         if (!channel->ch_equeue) {
 206                 channel->ch_equeue = (u8 *) kmalloc(EQUEUESIZE, GFP_KERNEL);
 207                 if (!channel->ch_equeue) {
 208                         jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
 209                                 "unable to allocate error queue buf");
 210                         return -ENOMEM;
 211                 }
 212                 memset(channel->ch_equeue, 0, EQUEUESIZE);
 213         }
 214         if (!channel->ch_wqueue) {
 215                 channel->ch_wqueue = (u8 *) kmalloc(WQUEUESIZE, GFP_KERNEL);
 216                 if (!channel->ch_wqueue) {
 217                         jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
 218                                 "unable to allocate write queue buf");
 219                         return -ENOMEM;
 220                 }
 221                 memset(channel->ch_wqueue, 0, WQUEUESIZE);
 222         }
 223
 224         channel->ch_flags &= ~(CH_OPENING);
 225         /*
 226          * Initialize if neither terminal is open.
 227          */
 228         jsm_printk(OPEN, INFO, &channel->ch_bd->pci_dev,
 229                 "jsm_open: initializing channel in open...\n");
 230
 231         /*
 232          * Flush input queues.
 233          */
 234         channel->ch_r_head = channel->ch_r_tail = 0;
 235         channel->ch_e_head = channel->ch_e_tail = 0;
 236         channel->ch_w_head = channel->ch_w_tail = 0;
 237
 238         brd->bd_ops->flush_uart_write(channel);
 239         brd->bd_ops->flush_uart_read(channel);
 240
 241         channel->ch_flags = 0;
 242         channel->ch_cached_lsr = 0;
 243         channel->ch_stops_sent = 0;
 244
 245         termios = port->info->tty->termios;
 246         channel->ch_c_cflag     = termios->c_cflag;
 247         channel->ch_c_iflag     = termios->c_iflag;
 248         channel->ch_c_oflag     = termios->c_oflag;
 249         channel->ch_c_lflag     = termios->c_lflag;
 250         channel->ch_startc      = termios->c_cc[VSTART];
 251         channel->ch_stopc       = termios->c_cc[VSTOP];
 252
 253         /* Tell UART to init itself */
 254         brd->bd_ops->uart_init(channel);
 255
 256         /*
 257          * Run param in case we changed anything
 258          */
 259         brd->bd_ops->param(channel);
 260
 261         jsm_carrier(channel);
 262
 263         channel->ch_open_count++;
 264
 265         jsm_printk(OPEN, INFO, &channel->ch_bd->pci_dev, "finish\n");
 266         return rc;
 267 }
 268
 269 static void jsm_tty_close(struct uart_port *port)
 270 {
 271         struct jsm_board *bd;
 272         struct ktermios *ts;
 273         struct jsm_channel *channel = (struct jsm_channel *)port;
 274
 275         jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev, "start\n");
 276
 277         bd = channel->ch_bd;
 278         ts = channel->uart_port.info->tty->termios;
 279
 280         channel->ch_flags &= ~(CH_STOPI);
 281
 282         channel->ch_open_count--;
 283
 284         /*
 285          * If we have HUPCL set, lower DTR and RTS
 286          */
 287         if (channel->ch_c_cflag & HUPCL) {
 288                 jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev,
 289                         "Close. HUPCL set, dropping DTR/RTS\n");
 290
 291                 /* Drop RTS/DTR */
 292                 channel->ch_mostat &= ~(UART_MCR_DTR | UART_MCR_RTS);
 293                 bd->bd_ops->assert_modem_signals(channel);
 294         }
 295
 296         channel->ch_old_baud = 0;
 297
 298         /* Turn off UART interrupts for this port */
 299         channel->ch_bd->bd_ops->uart_off(channel);
 300
 301         jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev, "finish\n");
 302 }
 303
 304 static void jsm_tty_set_termios(struct uart_port *port,
 305                                  struct ktermios *termios,
 306                                  struct ktermios *old_termios)
 307 {
 308         unsigned long lock_flags;
 309         struct jsm_channel *channel = (struct jsm_channel *)port;
 310
 311         spin_lock_irqsave(&port->lock, lock_flags);
 312         channel->ch_c_cflag     = termios->c_cflag;
 313         channel->ch_c_iflag     = termios->c_iflag;
 314         channel->ch_c_oflag     = termios->c_oflag;
 315         channel->ch_c_lflag     = termios->c_lflag;
 316         channel->ch_startc      = termios->c_cc[VSTART];
 317         channel->ch_stopc       = termios->c_cc[VSTOP];
 318
 319         channel->ch_bd->bd_ops->param(channel);
 320         jsm_carrier(channel);
 321         spin_unlock_irqrestore(&port->lock, lock_flags);
 322 }
 323
 324 static const char *jsm_tty_type(struct uart_port *port)
 325 {
 326         return "jsm";
 327 }
 328
 329 static void jsm_tty_release_port(struct uart_port *port)
 330 {
 331 }
 332
 333 static int jsm_tty_request_port(struct uart_port *port)
 334 {
 335         return 0;
 336 }
 337
 338 static void jsm_config_port(struct uart_port *port, int flags)
 339 {
 340         port->type = PORT_JSM;
 341 }
 342
 343 static struct uart_ops jsm_ops = {
 344         .tx_empty       = jsm_tty_tx_empty,
 345         .set_mctrl      = jsm_tty_set_mctrl,
 346         .get_mctrl      = jsm_tty_get_mctrl,
 347         .stop_tx        = jsm_tty_stop_tx,
 348         .start_tx       = jsm_tty_start_tx,
 349         .send_xchar     = jsm_tty_send_xchar,
 350         .stop_rx        = jsm_tty_stop_rx,
 351         .break_ctl      = jsm_tty_break,
 352         .startup        = jsm_tty_open,
 353         .shutdown       = jsm_tty_close,
 354         .set_termios    = jsm_tty_set_termios,
 355         .type           = jsm_tty_type,
 356         .release_port   = jsm_tty_release_port,
 357         .request_port   = jsm_tty_request_port,
 358         .config_port    = jsm_config_port,
 359 };
 360
 361 /*
 362  * jsm_tty_init()
 363  *
 364  * Init the tty subsystem.  Called once per board after board has been
 365  * downloaded and init'ed.
 366  */
 367 int jsm_tty_init(struct jsm_board *brd)
 368 {
 369         int i;
 370         void __iomem *vaddr;
 371         struct jsm_channel *ch;
 372
 373         if (!brd)
 374                 return -ENXIO;
 375
 376         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 377
 378         /*
 379          * Initialize board structure elements.
 380          */
 381
 382         brd->nasync = brd->maxports;
 383
 384         /*
 385          * Allocate channel memory that might not have been allocated
 386          * when the driver was first loaded.
 387          */
 388         for (i = 0; i < brd->nasync; i++) {
 389                 if (!brd->channels[i]) {
 390
 391                         /*
 392                          * Okay to malloc with GFP_KERNEL, we are not at
 393                          * interrupt context, and there are no locks held.
 394                          */
 395                         brd->channels[i] = kmalloc(sizeof(struct jsm_channel), GFP_KERNEL);
 396                         if (!brd->channels[i]) {
 397                                 jsm_printk(CORE, ERR, &brd->pci_dev,
 398                                         "%s:%d Unable to allocate memory for channel struct\n",
 399                                                          __FILE__, __LINE__);
 400                         }
 401                         memset(brd->channels[i], 0, sizeof(struct jsm_channel));
 402                 }
 403         }
 404
 405         ch = brd->channels[0];
 406         vaddr = brd->re_map_membase;
 407
 408         /* Set up channel variables */
 409         for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
 410
 411                 if (!brd->channels[i])
 412                         continue;
 413
 414                 spin_lock_init(&ch->ch_lock);
 415
 416                 if (brd->bd_uart_offset == 0x200)
 417                         ch->ch_neo_uart =  vaddr + (brd->bd_uart_offset * i);
 418
 419                 ch->ch_bd = brd;
 420                 ch->ch_portnum = i;
 421
 422                 /* .25 second delay */
 423                 ch->ch_close_delay = 250;
 424
 425                 init_waitqueue_head(&ch->ch_flags_wait);
 426         }
 427
 428         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 429         return 0;
 430 }
 431
 432 int jsm_uart_port_init(struct jsm_board *brd)
 433 {
 434         int i;
 435         struct jsm_channel *ch;
 436
 437         if (!brd)
 438                 return -ENXIO;
 439
 440         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 441
 442         /*
 443          * Initialize board structure elements.
 444          */
 445
 446         brd->nasync = brd->maxports;
 447
 448         /* Set up channel variables */
 449         for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
 450
 451                 if (!brd->channels[i])
 452                         continue;
 453
 454                 brd->channels[i]->uart_port.irq = brd->irq;
 455                 brd->channels[i]->uart_port.type = PORT_JSM;
 456                 brd->channels[i]->uart_port.iotype = UPIO_MEM;
 457                 brd->channels[i]->uart_port.membase = brd->re_map_membase;
 458                 brd->channels[i]->uart_port.fifosize = 16;
 459                 brd->channels[i]->uart_port.ops = &jsm_ops;
 460                 brd->channels[i]->uart_port.line = brd->channels[i]->ch_portnum + brd->boardnum * 2;
 461                 if (uart_add_one_port (&jsm_uart_driver, &brd->channels[i]->uart_port))
 462                         printk(KERN_INFO "Added device failed\n");
 463                 else
 464                         printk(KERN_INFO "Added device \n");
 465         }
 466
 467         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 468         return 0;
 469 }
 470
 471 int jsm_remove_uart_port(struct jsm_board *brd)
 472 {
 473         int i;
 474         struct jsm_channel *ch;
 475
 476         if (!brd)
 477                 return -ENXIO;
 478
 479         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 480
 481         /*
 482          * Initialize board structure elements.
 483          */
 484
 485         brd->nasync = brd->maxports;
 486
 487         /* Set up channel variables */
 488         for (i = 0; i < brd->nasync; i++) {
 489
 490                 if (!brd->channels[i])
 491                         continue;
 492
 493                 ch = brd->channels[i];
 494
 495                 uart_remove_one_port(&jsm_uart_driver, &brd->channels[i]->uart_port);
 496         }
 497
 498         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 499         return 0;
 500 }
 501
 502 void jsm_input(struct jsm_channel *ch)
 503 {
 504         struct jsm_board *bd;
 505         struct tty_struct *tp;
 506         struct tty_ldisc *ld;
 507         u32 rmask;
 508         u16 head;
 509         u16 tail;
 510         int data_len;
 511         unsigned long lock_flags;
 512         int flip_len = 0;
 513         int len = 0;
 514         int n = 0;
 515         int s = 0;
 516         int i = 0;
 517
 518         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n");
 519
 520         if (!ch)
 521                 return;
 522
 523         tp = ch->uart_port.info->tty;
 524
 525         bd = ch->ch_bd;
 526         if(!bd)
 527                 return;
 528
 529         spin_lock_irqsave(&ch->ch_lock, lock_flags);
 530
 531         /*
 532          *Figure the number of characters in the buffer.
 533          *Exit immediately if none.
 534          */
 535
 536         rmask = RQUEUEMASK;
 537
 538         head = ch->ch_r_head & rmask;
 539         tail = ch->ch_r_tail & rmask;
 540
 541         data_len = (head - tail) & rmask;
 542         if (data_len == 0) {
 543                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 544                 return;
 545         }
 546
 547         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n");
 548
 549         /*
 550          *If the device is not open, or CREAD is off, flush
 551          *input data and return immediately.
 552          */
 553         if (!tp ||
 554                 !(tp->termios->c_cflag & CREAD) ) {
 555
 556                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 557                         "input. dropping %d bytes on port %d...\n", data_len, ch->ch_portnum);
 558                 ch->ch_r_head = tail;
 559
 560                 /* Force queue flow control to be released, if needed */
 561                 jsm_check_queue_flow_control(ch);
 562
 563                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 564                 return;
 565         }
 566
 567         /*
 568          * If we are throttled, simply don't read any data.
 569          */
 570         if (ch->ch_flags & CH_STOPI) {
 571                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 572                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 573                         "Port %d throttled, not reading any data. head: %x tail: %x\n",
 574                         ch->ch_portnum, head, tail);
 575                 return;
 576         }
 577
 578         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start 2\n");
 579
 580         /*
 581          * If the rxbuf is empty and we are not throttled, put as much
 582          * as we can directly into the linux TTY buffer.
 583          *
 584          */
 585         flip_len = TTY_FLIPBUF_SIZE;
 586
 587         len = min(data_len, flip_len);
 588         len = min(len, (N_TTY_BUF_SIZE - 1) - tp->read_cnt);
 589         ld = tty_ldisc_ref(tp);
 590
 591         /*
 592          * If we were unable to get a reference to the ld,
 593          * don't flush our buffer, and act like the ld doesn't
 594          * have any space to put the data right now.
 595          */
 596         if (!ld) {
 597                 len = 0;
 598         } else {
 599                 /*
 600                  * If ld doesn't have a pointer to a receive_buf function,
 601                  * flush the data, then act like the ld doesn't have any
 602                  * space to put the data right now.
 603                  */
 604                 if (!ld->receive_buf) {
 605                                 ch->ch_r_head = ch->ch_r_tail;
 606                                 len = 0;
 607                 }
 608         }
 609
 610         if (len <= 0) {
 611                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 612                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "jsm_input 1\n");
 613                 if (ld)
 614                         tty_ldisc_deref(ld);
 615                 return;
 616         }
 617
 618         len = tty_buffer_request_room(tp, len);
 619         n = len;
 620
 621         /*
 622          * n now contains the most amount of data we can copy,
 623          * bounded either by the flip buffer size or the amount
 624          * of data the card actually has pending...
 625          */
 626         while (n) {
 627                 s = ((head >= tail) ? head : RQUEUESIZE) - tail;
 628                 s = min(s, n);
 629
 630                 if (s <= 0)
 631                         break;
 632
 633                         /*
 634                          * If conditions are such that ld needs to see all
 635                          * UART errors, we will have to walk each character
 636                          * and error byte and send them to the buffer one at
 637                          * a time.
 638                          */
 639
 640                 if (I_PARMRK(tp) || I_BRKINT(tp) || I_INPCK(tp)) {
 641                         for (i = 0; i < s; i++) {
 642                                 /*
 643                                  * Give the Linux ld the flags in the
 644                                  * format it likes.
 645                                  */
 646                                 if (*(ch->ch_equeue +tail +i) & UART_LSR_BI)
 647                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i),  TTY_BREAK);
 648                                 else if (*(ch->ch_equeue +tail +i) & UART_LSR_PE)
 649                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_PARITY);
 650                                 else if (*(ch->ch_equeue +tail +i) & UART_LSR_FE)
 651                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_FRAME);
 652                                 else
 653                                 tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_NORMAL);
 654                         }
 655                 } else {
 656                         tty_insert_flip_string(tp, ch->ch_rqueue + tail, s) ;
 657                 }
 658                 tail += s;
 659                 n -= s;
 660                 /* Flip queue if needed */
 661                 tail &= rmask;
 662         }
 663
 664         ch->ch_r_tail = tail & rmask;
 665         ch->ch_e_tail = tail & rmask;
 666         jsm_check_queue_flow_control(ch);
 667         spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 668
 669         /* Tell the tty layer its okay to "eat" the data now */
 670         tty_flip_buffer_push(tp);
 671
 672         if (ld)
 673                 tty_ldisc_deref(ld);
 674
 675         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "finish\n");
 676 }
 677
 678 static void jsm_carrier(struct jsm_channel *ch)
 679 {
 680         struct jsm_board *bd;
 681
 682         int virt_carrier = 0;
 683         int phys_carrier = 0;
 684
 685         jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev, "start\n");
 686         if (!ch)
 687                 return;
 688
 689         bd = ch->ch_bd;
 690
 691         if (!bd)
 692                 return;
 693
 694         if (ch->ch_mistat & UART_MSR_DCD) {
 695                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 696                         "mistat: %x D_CD: %x\n", ch->ch_mistat, ch->ch_mistat & UART_MSR_DCD);
 697                 phys_carrier = 1;
 698         }
 699
 700         if (ch->ch_c_cflag & CLOCAL)
 701                 virt_carrier = 1;
 702
 703         jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 704                 "DCD: physical: %d virt: %d\n", phys_carrier, virt_carrier);
 705
 706         /*
 707          * Test for a VIRTUAL carrier transition to HIGH.
 708          */
 709         if (((ch->ch_flags & CH_FCAR) == 0) && (virt_carrier == 1)) {
 710
 711                 /*
 712                  * When carrier rises, wake any threads waiting
 713                  * for carrier in the open routine.
 714                  */
 715
 716                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 717                         "carrier: virt DCD rose\n");
 718
 719                 if (waitqueue_active(&(ch->ch_flags_wait)))
 720                         wake_up_interruptible(&ch->ch_flags_wait);
 721         }
 722
 723         /*
 724          * Test for a PHYSICAL carrier transition to HIGH.
 725          */
 726         if (((ch->ch_flags & CH_CD) == 0) && (phys_carrier == 1)) {
 727
 728                 /*
 729                  * When carrier rises, wake any threads waiting
 730                  * for carrier in the open routine.
 731                  */
 732
 733                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 734                         "carrier: physical DCD rose\n");
 735
 736                 if (waitqueue_active(&(ch->ch_flags_wait)))
 737                         wake_up_interruptible(&ch->ch_flags_wait);
 738         }
 739
 740         /*
 741          *  Test for a PHYSICAL transition to low, so long as we aren't
 742          *  currently ignoring physical transitions (which is what "virtual
 743          *  carrier" indicates).
 744          *
 745          *  The transition of the virtual carrier to low really doesn't
 746          *  matter... it really only means "ignore carrier state", not
 747          *  "make pretend that carrier is there".
 748          */
 749         if ((virt_carrier == 0) && ((ch->ch_flags & CH_CD) != 0)
 750                         && (phys_carrier == 0)) {
 751                 /*
 752                  *      When carrier drops:
 753                  *
 754                  *      Drop carrier on all open units.
 755                  *
 756                  *      Flush queues, waking up any task waiting in the
 757                  *      line discipline.
 758                  *
 759                  *      Send a hangup to the control terminal.
 760                  *
 761                  *      Enable all select calls.
 762                  */
 763                 if (waitqueue_active(&(ch->ch_flags_wait)))
 764                         wake_up_interruptible(&ch->ch_flags_wait);
 765         }
 766
 767         /*
 768          *  Make sure that our cached values reflect the current reality.
 769          */
 770         if (virt_carrier == 1)
 771                 ch->ch_flags |= CH_FCAR;
 772         else
 773                 ch->ch_flags &= ~CH_FCAR;
 774
 775         if (phys_carrier == 1)
 776                 ch->ch_flags |= CH_CD;
 777         else
 778                 ch->ch_flags &= ~CH_CD;
 779 }
 780
 781
 782 void jsm_check_queue_flow_control(struct jsm_channel *ch)
 783 {
 784         struct board_ops *bd_ops = ch->ch_bd->bd_ops;
 785         int qleft = 0;
 786
 787         /* Store how much space we have left in the queue */
 788         if ((qleft = ch->ch_r_tail - ch->ch_r_head - 1) < 0)
 789                 qleft += RQUEUEMASK + 1;
 790
 791         /*
 792          * Check to see if we should enforce flow control on our queue because
 793          * the ld (or user) isn't reading data out of our queue fast enuf.
 794          *
 795          * NOTE: This is done based on what the current flow control of the
 796          * port is set for.
 797          *
 798          * 1) HWFLOW (RTS) - Turn off the UART's Receive interrupt.
 799          *      This will cause the UART's FIFO to back up, and force
 800          *      the RTS signal to be dropped.
 801          * 2) SWFLOW (IXOFF) - Keep trying to send a stop character to
 802          *      the other side, in hopes it will stop sending data to us.
 803          * 3) NONE - Nothing we can do.  We will simply drop any extra data
 804          *      that gets sent into us when the queue fills up.
 805          */
 806         if (qleft < 256) {
 807                 /* HWFLOW */
 808                 if (ch->ch_c_cflag & CRTSCTS) {
 809                         if(!(ch->ch_flags & CH_RECEIVER_OFF)) {
 810                                 bd_ops->disable_receiver(ch);
 811                                 ch->ch_flags |= (CH_RECEIVER_OFF);
 812                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 813                                         "Internal queue hit hilevel mark (%d)! Turning off interrupts.\n",
 814                                         qleft);
 815                         }
 816                 }
 817                 /* SWFLOW */
 818                 else if (ch->ch_c_iflag & IXOFF) {
 819                         if (ch->ch_stops_sent <= MAX_STOPS_SENT) {
 820                                 bd_ops->send_stop_character(ch);
 821                                 ch->ch_stops_sent++;
 822                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 823                                         "Sending stop char! Times sent: %x\n", ch->ch_stops_sent);
 824                         }
 825                 }
 826         }
 827
 828         /*
 829          * Check to see if we should unenforce flow control because
 830          * ld (or user) finally read enuf data out of our queue.
 831          *
 832          * NOTE: This is done based on what the current flow control of the
 833          * port is set for.
 834          *
 835          * 1) HWFLOW (RTS) - Turn back on the UART's Receive interrupt.
 836          *      This will cause the UART's FIFO to raise RTS back up,
 837          *      which will allow the other side to start sending data again.
 838          * 2) SWFLOW (IXOFF) - Send a start character to
 839          *      the other side, so it will start sending data to us again.
 840          * 3) NONE - Do nothing. Since we didn't do anything to turn off the
 841          *      other side, we don't need to do anything now.
 842          */
 843         if (qleft > (RQUEUESIZE / 2)) {
 844                 /* HWFLOW */
 845                 if (ch->ch_c_cflag & CRTSCTS) {
 846                         if (ch->ch_flags & CH_RECEIVER_OFF) {
 847                                 bd_ops->enable_receiver(ch);
 848                                 ch->ch_flags &= ~(CH_RECEIVER_OFF);
 849                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 850                                         "Internal queue hit lowlevel mark (%d)! Turning on interrupts.\n",
 851                                         qleft);
 852                         }
 853                 }
 854                 /* SWFLOW */
 855                 else if (ch->ch_c_iflag & IXOFF && ch->ch_stops_sent) {
 856                         ch->ch_stops_sent = 0;
 857                         bd_ops->send_start_character(ch);
 858                         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "Sending start char!\n");
 859                 }
 860         }
 861 }
 862
 863 /*
 864  * jsm_tty_write()
 865  *
 866  * Take data from the user or kernel and send it out to the FEP.
 867  * In here exists all the Transparent Print magic as well.
 868  */
 869 int jsm_tty_write(struct uart_port *port)
 870 {
 871         int bufcount = 0, n = 0;
 872         int data_count = 0,data_count1 =0;
 873         u16 head;
 874         u16 tail;
 875         u16 tmask;
 876         u32 remain;
 877         int temp_tail = port->info->xmit.tail;
 878         struct jsm_channel *channel = (struct jsm_channel *)port;
 879
 880         tmask = WQUEUEMASK;
 881         head = (channel->ch_w_head) & tmask;
 882         tail = (channel->ch_w_tail) & tmask;
 883
 884         if ((bufcount = tail - head - 1) < 0)
 885                 bufcount += WQUEUESIZE;
 886
 887         n = bufcount;
 888
 889         n = min(n, 56);
 890         remain = WQUEUESIZE - head;
 891
 892         data_count = 0;
 893         if (n >= remain) {
 894                 n -= remain;
 895                 while ((port->info->xmit.head != temp_tail) &&
 896                 (data_count < remain)) {
 897                         channel->ch_wqueue[head++] =
 898                         port->info->xmit.buf[temp_tail];
 899
 900                         temp_tail++;
 901                         temp_tail &= (UART_XMIT_SIZE - 1);
 902                         data_count++;
 903                 }
 904                 if (data_count == remain) head = 0;
 905         }
 906
 907         data_count1 = 0;
 908         if (n > 0) {
 909                 remain = n;
 910                 while ((port->info->xmit.head != temp_tail) &&
 911                         (data_count1 < remain)) {
 912                         channel->ch_wqueue[head++] =
 913                                 port->info->xmit.buf[temp_tail];
 914
 915                         temp_tail++;
 916                         temp_tail &= (UART_XMIT_SIZE - 1);
 917                         data_count1++;
 918
 919                 }
 920         }
 921
 922         port->info->xmit.tail = temp_tail;
 923
 924         data_count += data_count1;
 925         if (data_count) {
 926                 head &= tmask;
 927                 channel->ch_w_head = head;
 928         }
 929
 930         if (data_count) {
 931                 channel->ch_bd->bd_ops->copy_data_from_queue_to_uart(channel);
 932         }
 933
 934         return data_count;
 935 }