drivers/serial/jsm/jsm_tty.c

   1 /************************************************************************
   2  * Copyright 2003 Digi International (www.digi.com)
   3  *
   4  * Copyright (C) 2004 IBM Corporation. All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2, or (at your option)
   9  * any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED; without even the
  13  * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  14  * PURPOSE.  See the GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 * Temple Place - Suite 330, Boston,
  19  * MA  02111-1307, USA.
  20  *
  21  * Contact Information:
  22  * Scott H Kilau <Scott_Kilau@digi.com>
  23  * Ananda Venkatarman <mansarov@us.ibm.com>
  24  * Modifications:
  25  * 01/19/06:    changed jsm_input routine to use the dynamically allocated
  26  *              tty_buffer changes. Contributors: Scott Kilau and Ananda V.
  27  ***********************************************************************/
  28 #include <linux/tty.h>
  29 #include <linux/tty_flip.h>
  30 #include <linux/serial_reg.h>
  31 #include <linux/delay.h>        /* For udelay */
  32 #include <linux/pci.h>
  33
  34 #include "jsm.h"
  35
  36 static void jsm_carrier(struct jsm_channel *ch);
  37
  38 static inline int jsm_get_mstat(struct jsm_channel *ch)
  39 {
  40         unsigned char mstat;
  41         unsigned result;
  42
  43         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "start\n");
  44
  45         mstat = (ch->ch_mostat | ch->ch_mistat);
  46
  47         result = 0;
  48
  49         if (mstat & UART_MCR_DTR)
  50                 result |= TIOCM_DTR;
  51         if (mstat & UART_MCR_RTS)
  52                 result |= TIOCM_RTS;
  53         if (mstat & UART_MSR_CTS)
  54                 result |= TIOCM_CTS;
  55         if (mstat & UART_MSR_DSR)
  56                 result |= TIOCM_DSR;
  57         if (mstat & UART_MSR_RI)
  58                 result |= TIOCM_RI;
  59         if (mstat & UART_MSR_DCD)
  60                 result |= TIOCM_CD;
  61
  62         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "finish\n");
  63         return result;
  64 }
  65
  66 static unsigned int jsm_tty_tx_empty(struct uart_port *port)
  67 {
  68         return TIOCSER_TEMT;
  69 }
  70
  71 /*
  72  * Return modem signals to ld.
  73  */
  74 static unsigned int jsm_tty_get_mctrl(struct uart_port *port)
  75 {
  76         int result;
  77         struct jsm_channel *channel = (struct jsm_channel *)port;
  78
  79         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
  80
  81         result = jsm_get_mstat(channel);
  82
  83         if (result < 0)
  84                 return -ENXIO;
  85
  86         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
  87
  88         return result;
  89 }
  90
  91 /*
  92  * jsm_set_modem_info()
  93  *
  94  * Set modem signals, called by ld.
  95  */
  96 static void jsm_tty_set_mctrl(struct uart_port *port, unsigned int mctrl)
  97 {
  98         struct jsm_channel *channel = (struct jsm_channel *)port;
  99
 100         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
 101
 102         if (mctrl & TIOCM_RTS)
 103                 channel->ch_mostat |= UART_MCR_RTS;
 104         else
 105                 channel->ch_mostat &= ~UART_MCR_RTS;
 106
 107         if (mctrl & TIOCM_DTR)
 108                 channel->ch_mostat |= UART_MCR_DTR;
 109         else
 110                 channel->ch_mostat &= ~UART_MCR_DTR;
 111
 112         channel->ch_bd->bd_ops->assert_modem_signals(channel);
 113
 114         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
 115         udelay(10);
 116 }
 117
 118 static void jsm_tty_start_tx(struct uart_port *port)
 119 {
 120         struct jsm_channel *channel = (struct jsm_channel *)port;
 121
 122         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
 123
 124         channel->ch_flags &= ~(CH_STOP);
 125         jsm_tty_write(port);
 126
 127         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
 128 }
 129
 130 static void jsm_tty_stop_tx(struct uart_port *port)
 131 {
 132         struct jsm_channel *channel = (struct jsm_channel *)port;
 133
 134         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
 135
 136         channel->ch_flags |= (CH_STOP);
 137
 138         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
 139 }
 140
 141 static void jsm_tty_send_xchar(struct uart_port *port, char ch)
 142 {
 143         unsigned long lock_flags;
 144         struct jsm_channel *channel = (struct jsm_channel *)port;
 145
 146         spin_lock_irqsave(&port->lock, lock_flags);
 147         if (ch == port->info->tty->termios->c_cc[VSTART])
 148                 channel->ch_bd->bd_ops->send_start_character(channel);
 149
 150         if (ch == port->info->tty->termios->c_cc[VSTOP])
 151                 channel->ch_bd->bd_ops->send_stop_character(channel);
 152         spin_unlock_irqrestore(&port->lock, lock_flags);
 153 }
 154
 155 static void jsm_tty_stop_rx(struct uart_port *port)
 156 {
 157         struct jsm_channel *channel = (struct jsm_channel *)port;
 158
 159         channel->ch_bd->bd_ops->disable_receiver(channel);
 160 }
 161
 162 static void jsm_tty_break(struct uart_port *port, int break_state)
 163 {
 164         unsigned long lock_flags;
 165         struct jsm_channel *channel = (struct jsm_channel *)port;
 166
 167         spin_lock_irqsave(&port->lock, lock_flags);
 168         if (break_state == -1)
 169                 channel->ch_bd->bd_ops->send_break(channel);
 170         else
 171                 channel->ch_bd->bd_ops->clear_break(channel, 0);
 172
 173         spin_unlock_irqrestore(&port->lock, lock_flags);
 174 }
 175
 176 static int jsm_tty_open(struct uart_port *port)
 177 {
 178         struct jsm_board *brd;
 179         int rc = 0;
 180         struct jsm_channel *channel = (struct jsm_channel *)port;
 181
 182         /* Get board pointer from our array of majors we have allocated */
 183         brd = channel->ch_bd;
 184
 185         /*
 186          * Allocate channel buffers for read/write/error.
 187          * Set flag, so we don't get trounced on.
 188          */
 189         channel->ch_flags |= (CH_OPENING);
 190
 191         /* Drop locks, as malloc with GFP_KERNEL can sleep */
 192
 193         if (!channel->ch_rqueue) {
 194                 channel->ch_rqueue = (u8 *) kmalloc(RQUEUESIZE, GFP_KERNEL);
 195                 if (!channel->ch_rqueue) {
 196                         jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
 197                                 "unable to allocate read queue buf");
 198                         return -ENOMEM;
 199                 }
 200                 memset(channel->ch_rqueue, 0, RQUEUESIZE);
 201         }
 202         if (!channel->ch_equeue) {
 203                 channel->ch_equeue = (u8 *) kmalloc(EQUEUESIZE, GFP_KERNEL);
 204                 if (!channel->ch_equeue) {
 205                         jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
 206                                 "unable to allocate error queue buf");
 207                         return -ENOMEM;
 208                 }
 209                 memset(channel->ch_equeue, 0, EQUEUESIZE);
 210         }
 211         if (!channel->ch_wqueue) {
 212                 channel->ch_wqueue = (u8 *) kmalloc(WQUEUESIZE, GFP_KERNEL);
 213                 if (!channel->ch_wqueue) {
 214                         jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
 215                                 "unable to allocate write queue buf");
 216                         return -ENOMEM;
 217                 }
 218                 memset(channel->ch_wqueue, 0, WQUEUESIZE);
 219         }
 220
 221         channel->ch_flags &= ~(CH_OPENING);
 222         /*
 223          * Initialize if neither terminal is open.
 224          */
 225         jsm_printk(OPEN, INFO, &channel->ch_bd->pci_dev,
 226                 "jsm_open: initializing channel in open...\n");
 227
 228         /*
 229          * Flush input queues.
 230          */
 231         channel->ch_r_head = channel->ch_r_tail = 0;
 232         channel->ch_e_head = channel->ch_e_tail = 0;
 233         channel->ch_w_head = channel->ch_w_tail = 0;
 234
 235         brd->bd_ops->flush_uart_write(channel);
 236         brd->bd_ops->flush_uart_read(channel);
 237
 238         channel->ch_flags = 0;
 239         channel->ch_cached_lsr = 0;
 240         channel->ch_stops_sent = 0;
 241
 242         channel->ch_c_cflag     = port->info->tty->termios->c_cflag;
 243         channel->ch_c_iflag     = port->info->tty->termios->c_iflag;
 244         channel->ch_c_oflag     = port->info->tty->termios->c_oflag;
 245         channel->ch_c_lflag     = port->info->tty->termios->c_lflag;
 246         channel->ch_startc = port->info->tty->termios->c_cc[VSTART];
 247         channel->ch_stopc = port->info->tty->termios->c_cc[VSTOP];
 248
 249         /* Tell UART to init itself */
 250         brd->bd_ops->uart_init(channel);
 251
 252         /*
 253          * Run param in case we changed anything
 254          */
 255         brd->bd_ops->param(channel);
 256
 257         jsm_carrier(channel);
 258
 259         channel->ch_open_count++;
 260
 261         jsm_printk(OPEN, INFO, &channel->ch_bd->pci_dev, "finish\n");
 262         return rc;
 263 }
 264
 265 static void jsm_tty_close(struct uart_port *port)
 266 {
 267         struct jsm_board *bd;
 268         struct termios *ts;
 269         struct jsm_channel *channel = (struct jsm_channel *)port;
 270
 271         jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev, "start\n");
 272
 273         bd = channel->ch_bd;
 274         ts = channel->uart_port.info->tty->termios;
 275
 276         channel->ch_flags &= ~(CH_STOPI);
 277
 278         channel->ch_open_count--;
 279
 280         /*
 281          * If we have HUPCL set, lower DTR and RTS
 282          */
 283         if (channel->ch_c_cflag & HUPCL) {
 284                 jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev,
 285                         "Close. HUPCL set, dropping DTR/RTS\n");
 286
 287                 /* Drop RTS/DTR */
 288                 channel->ch_mostat &= ~(UART_MCR_DTR | UART_MCR_RTS);
 289                 bd->bd_ops->assert_modem_signals(channel);
 290         }
 291
 292         channel->ch_old_baud = 0;
 293
 294         /* Turn off UART interrupts for this port */
 295         channel->ch_bd->bd_ops->uart_off(channel);
 296
 297         jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev, "finish\n");
 298 }
 299
 300 static void jsm_tty_set_termios(struct uart_port *port,
 301                                  struct termios *termios,
 302                                  struct termios *old_termios)
 303 {
 304         unsigned long lock_flags;
 305         struct jsm_channel *channel = (struct jsm_channel *)port;
 306
 307         spin_lock_irqsave(&port->lock, lock_flags);
 308         channel->ch_c_cflag     = termios->c_cflag;
 309         channel->ch_c_iflag     = termios->c_iflag;
 310         channel->ch_c_oflag     = termios->c_oflag;
 311         channel->ch_c_lflag     = termios->c_lflag;
 312         channel->ch_startc      = termios->c_cc[VSTART];
 313         channel->ch_stopc       = termios->c_cc[VSTOP];
 314
 315         channel->ch_bd->bd_ops->param(channel);
 316         jsm_carrier(channel);
 317         spin_unlock_irqrestore(&port->lock, lock_flags);
 318 }
 319
 320 static const char *jsm_tty_type(struct uart_port *port)
 321 {
 322         return "jsm";
 323 }
 324
 325 static void jsm_tty_release_port(struct uart_port *port)
 326 {
 327 }
 328
 329 static int jsm_tty_request_port(struct uart_port *port)
 330 {
 331         return 0;
 332 }
 333
 334 static void jsm_config_port(struct uart_port *port, int flags)
 335 {
 336         port->type = PORT_JSM;
 337 }
 338
 339 static struct uart_ops jsm_ops = {
 340         .tx_empty       = jsm_tty_tx_empty,
 341         .set_mctrl      = jsm_tty_set_mctrl,
 342         .get_mctrl      = jsm_tty_get_mctrl,
 343         .stop_tx        = jsm_tty_stop_tx,
 344         .start_tx       = jsm_tty_start_tx,
 345         .send_xchar     = jsm_tty_send_xchar,
 346         .stop_rx        = jsm_tty_stop_rx,
 347         .break_ctl      = jsm_tty_break,
 348         .startup        = jsm_tty_open,
 349         .shutdown       = jsm_tty_close,
 350         .set_termios    = jsm_tty_set_termios,
 351         .type           = jsm_tty_type,
 352         .release_port   = jsm_tty_release_port,
 353         .request_port   = jsm_tty_request_port,
 354         .config_port    = jsm_config_port,
 355 };
 356
 357 /*
 358  * jsm_tty_init()
 359  *
 360  * Init the tty subsystem.  Called once per board after board has been
 361  * downloaded and init'ed.
 362  */
 363 int jsm_tty_init(struct jsm_board *brd)
 364 {
 365         int i;
 366         void __iomem *vaddr;
 367         struct jsm_channel *ch;
 368
 369         if (!brd)
 370                 return -ENXIO;
 371
 372         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 373
 374         /*
 375          * Initialize board structure elements.
 376          */
 377
 378         brd->nasync = brd->maxports;
 379
 380         /*
 381          * Allocate channel memory that might not have been allocated
 382          * when the driver was first loaded.
 383          */
 384         for (i = 0; i < brd->nasync; i++) {
 385                 if (!brd->channels[i]) {
 386
 387                         /*
 388                          * Okay to malloc with GFP_KERNEL, we are not at
 389                          * interrupt context, and there are no locks held.
 390                          */
 391                         brd->channels[i] = kmalloc(sizeof(struct jsm_channel), GFP_KERNEL);
 392                         if (!brd->channels[i]) {
 393                                 jsm_printk(CORE, ERR, &brd->pci_dev,
 394                                         "%s:%d Unable to allocate memory for channel struct\n",
 395                                                          __FILE__, __LINE__);
 396                         }
 397                         memset(brd->channels[i], 0, sizeof(struct jsm_channel));
 398                 }
 399         }
 400
 401         ch = brd->channels[0];
 402         vaddr = brd->re_map_membase;
 403
 404         /* Set up channel variables */
 405         for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
 406
 407                 if (!brd->channels[i])
 408                         continue;
 409
 410                 spin_lock_init(&ch->ch_lock);
 411
 412                 if (brd->bd_uart_offset == 0x200)
 413                         ch->ch_neo_uart =  vaddr + (brd->bd_uart_offset * i);
 414
 415                 ch->ch_bd = brd;
 416                 ch->ch_portnum = i;
 417
 418                 /* .25 second delay */
 419                 ch->ch_close_delay = 250;
 420
 421                 init_waitqueue_head(&ch->ch_flags_wait);
 422         }
 423
 424         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 425         return 0;
 426 }
 427
 428 int jsm_uart_port_init(struct jsm_board *brd)
 429 {
 430         int i;
 431         struct jsm_channel *ch;
 432
 433         if (!brd)
 434                 return -ENXIO;
 435
 436         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 437
 438         /*
 439          * Initialize board structure elements.
 440          */
 441
 442         brd->nasync = brd->maxports;
 443
 444         /* Set up channel variables */
 445         for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
 446
 447                 if (!brd->channels[i])
 448                         continue;
 449
 450                 brd->channels[i]->uart_port.irq = brd->irq;
 451                 brd->channels[i]->uart_port.type = PORT_JSM;
 452                 brd->channels[i]->uart_port.iotype = UPIO_MEM;
 453                 brd->channels[i]->uart_port.membase = brd->re_map_membase;
 454                 brd->channels[i]->uart_port.fifosize = 16;
 455                 brd->channels[i]->uart_port.ops = &jsm_ops;
 456                 brd->channels[i]->uart_port.line = brd->channels[i]->ch_portnum + brd->boardnum * 2;
 457                 if (uart_add_one_port (&jsm_uart_driver, &brd->channels[i]->uart_port))
 458                         printk(KERN_INFO "Added device failed\n");
 459                 else
 460                         printk(KERN_INFO "Added device \n");
 461         }
 462
 463         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 464         return 0;
 465 }
 466
 467 int jsm_remove_uart_port(struct jsm_board *brd)
 468 {
 469         int i;
 470         struct jsm_channel *ch;
 471
 472         if (!brd)
 473                 return -ENXIO;
 474
 475         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 476
 477         /*
 478          * Initialize board structure elements.
 479          */
 480
 481         brd->nasync = brd->maxports;
 482
 483         /* Set up channel variables */
 484         for (i = 0; i < brd->nasync; i++) {
 485
 486                 if (!brd->channels[i])
 487                         continue;
 488
 489                 ch = brd->channels[i];
 490
 491                 uart_remove_one_port(&jsm_uart_driver, &brd->channels[i]->uart_port);
 492         }
 493
 494         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 495         return 0;
 496 }
 497
 498 void jsm_input(struct jsm_channel *ch)
 499 {
 500         struct jsm_board *bd;
 501         struct tty_struct *tp;
 502         struct tty_ldisc *ld;
 503         u32 rmask;
 504         u16 head;
 505         u16 tail;
 506         int data_len;
 507         unsigned long lock_flags;
 508         int flip_len = 0;
 509         int len = 0;
 510         int n = 0;
 511         char *buf = NULL;
 512         int s = 0;
 513         int i = 0;
 514
 515         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n");
 516
 517         if (!ch)
 518                 return;
 519
 520         tp = ch->uart_port.info->tty;
 521
 522         bd = ch->ch_bd;
 523         if(!bd)
 524                 return;
 525
 526         spin_lock_irqsave(&ch->ch_lock, lock_flags);
 527
 528         /*
 529          *Figure the number of characters in the buffer.
 530          *Exit immediately if none.
 531          */
 532
 533         rmask = RQUEUEMASK;
 534
 535         head = ch->ch_r_head & rmask;
 536         tail = ch->ch_r_tail & rmask;
 537
 538         data_len = (head - tail) & rmask;
 539         if (data_len == 0) {
 540                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 541                 return;
 542         }
 543
 544         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n");
 545
 546         /*
 547          *If the device is not open, or CREAD is off, flush
 548          *input data and return immediately.
 549          */
 550         if (!tp ||
 551                 !(tp->termios->c_cflag & CREAD) ) {
 552
 553                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 554                         "input. dropping %d bytes on port %d...\n", data_len, ch->ch_portnum);
 555                 ch->ch_r_head = tail;
 556
 557                 /* Force queue flow control to be released, if needed */
 558                 jsm_check_queue_flow_control(ch);
 559
 560                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 561                 return;
 562         }
 563
 564         /*
 565          * If we are throttled, simply don't read any data.
 566          */
 567         if (ch->ch_flags & CH_STOPI) {
 568                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 569                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 570                         "Port %d throttled, not reading any data. head: %x tail: %x\n",
 571                         ch->ch_portnum, head, tail);
 572                 return;
 573         }
 574
 575         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start 2\n");
 576
 577         /*
 578          * If the rxbuf is empty and we are not throttled, put as much
 579          * as we can directly into the linux TTY buffer.
 580          *
 581          */
 582         flip_len = TTY_FLIPBUF_SIZE;
 583
 584         len = min(data_len, flip_len);
 585         len = min(len, (N_TTY_BUF_SIZE - 1) - tp->read_cnt);
 586         ld = tty_ldisc_ref(tp);
 587
 588         /*
 589          * If the DONT_FLIP flag is on, don't flush our buffer, and act
 590          * like the ld doesn't have any space to put the data right now.
 591          */
 592         if (test_bit(TTY_DONT_FLIP, &tp->flags))
 593                 len = 0;
 594
 595         /*
 596          * If we were unable to get a reference to the ld,
 597          * don't flush our buffer, and act like the ld doesn't
 598          * have any space to put the data right now.
 599          */
 600         if (!ld) {
 601                 len = 0;
 602         } else {
 603                 /*
 604                  * If ld doesn't have a pointer to a receive_buf function,
 605                  * flush the data, then act like the ld doesn't have any
 606                  * space to put the data right now.
 607                  */
 608                 if (!ld->receive_buf) {
 609                                 ch->ch_r_head = ch->ch_r_tail;
 610                                 len = 0;
 611                 }
 612         }
 613
 614         if (len <= 0) {
 615                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 616                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "jsm_input 1\n");
 617                 if (ld)
 618                         tty_ldisc_deref(ld);
 619                 return;
 620         }
 621
 622         len = tty_buffer_request_room(tp, len);
 623         n = len;
 624
 625         /*
 626          * n now contains the most amount of data we can copy,
 627          * bounded either by the flip buffer size or the amount
 628          * of data the card actually has pending...
 629          */
 630         while (n) {
 631                 s = ((head >= tail) ? head : RQUEUESIZE) - tail;
 632                 s = min(s, n);
 633
 634                 if (s <= 0)
 635                         break;
 636
 637                         /*
 638                          * If conditions are such that ld needs to see all
 639                          * UART errors, we will have to walk each character
 640                          * and error byte and send them to the buffer one at
 641                          * a time.
 642                          */
 643
 644                 if (I_PARMRK(tp) || I_BRKINT(tp) || I_INPCK(tp)) {
 645                         for (i = 0; i < s; i++) {
 646                                 /*
 647                                  * Give the Linux ld the flags in the
 648                                  * format it likes.
 649                                  */
 650                                 if (*(ch->ch_equeue +tail +i) & UART_LSR_BI)
 651                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i),  TTY_BREAK);
 652                                 else if (*(ch->ch_equeue +tail +i) & UART_LSR_PE)
 653                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_PARITY);
 654                                 else if (*(ch->ch_equeue +tail +i) & UART_LSR_FE)
 655                                         tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_FRAME);
 656                                 else
 657                                 tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_NORMAL);
 658                         }
 659                 } else {
 660                         tty_insert_flip_string(tp, ch->ch_rqueue + tail, s) ;
 661                 }
 662                 tail += s;
 663                 n -= s;
 664                 /* Flip queue if needed */
 665                 tail &= rmask;
 666         }
 667
 668         ch->ch_r_tail = tail & rmask;
 669         ch->ch_e_tail = tail & rmask;
 670         jsm_check_queue_flow_control(ch);
 671         spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 672
 673         /* Tell the tty layer its okay to "eat" the data now */
 674         tty_flip_buffer_push(tp);
 675
 676         if (ld)
 677                 tty_ldisc_deref(ld);
 678
 679         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "finish\n");
 680 }
 681
 682 static void jsm_carrier(struct jsm_channel *ch)
 683 {
 684         struct jsm_board *bd;
 685
 686         int virt_carrier = 0;
 687         int phys_carrier = 0;
 688
 689         jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev, "start\n");
 690         if (!ch)
 691                 return;
 692
 693         bd = ch->ch_bd;
 694
 695         if (!bd)
 696                 return;
 697
 698         if (ch->ch_mistat & UART_MSR_DCD) {
 699                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 700                         "mistat: %x D_CD: %x\n", ch->ch_mistat, ch->ch_mistat & UART_MSR_DCD);
 701                 phys_carrier = 1;
 702         }
 703
 704         if (ch->ch_c_cflag & CLOCAL)
 705                 virt_carrier = 1;
 706
 707         jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 708                 "DCD: physical: %d virt: %d\n", phys_carrier, virt_carrier);
 709
 710         /*
 711          * Test for a VIRTUAL carrier transition to HIGH.
 712          */
 713         if (((ch->ch_flags & CH_FCAR) == 0) && (virt_carrier == 1)) {
 714
 715                 /*
 716                  * When carrier rises, wake any threads waiting
 717                  * for carrier in the open routine.
 718                  */
 719
 720                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 721                         "carrier: virt DCD rose\n");
 722
 723                 if (waitqueue_active(&(ch->ch_flags_wait)))
 724                         wake_up_interruptible(&ch->ch_flags_wait);
 725         }
 726
 727         /*
 728          * Test for a PHYSICAL carrier transition to HIGH.
 729          */
 730         if (((ch->ch_flags & CH_CD) == 0) && (phys_carrier == 1)) {
 731
 732                 /*
 733                  * When carrier rises, wake any threads waiting
 734                  * for carrier in the open routine.
 735                  */
 736
 737                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 738                         "carrier: physical DCD rose\n");
 739
 740                 if (waitqueue_active(&(ch->ch_flags_wait)))
 741                         wake_up_interruptible(&ch->ch_flags_wait);
 742         }
 743
 744         /*
 745          *  Test for a PHYSICAL transition to low, so long as we aren't
 746          *  currently ignoring physical transitions (which is what "virtual
 747          *  carrier" indicates).
 748          *
 749          *  The transition of the virtual carrier to low really doesn't
 750          *  matter... it really only means "ignore carrier state", not
 751          *  "make pretend that carrier is there".
 752          */
 753         if ((virt_carrier == 0) && ((ch->ch_flags & CH_CD) != 0)
 754                         && (phys_carrier == 0)) {
 755                 /*
 756                  *      When carrier drops:
 757                  *
 758                  *      Drop carrier on all open units.
 759                  *
 760                  *      Flush queues, waking up any task waiting in the
 761                  *      line discipline.
 762                  *
 763                  *      Send a hangup to the control terminal.
 764                  *
 765                  *      Enable all select calls.
 766                  */
 767                 if (waitqueue_active(&(ch->ch_flags_wait)))
 768                         wake_up_interruptible(&ch->ch_flags_wait);
 769         }
 770
 771         /*
 772          *  Make sure that our cached values reflect the current reality.
 773          */
 774         if (virt_carrier == 1)
 775                 ch->ch_flags |= CH_FCAR;
 776         else
 777                 ch->ch_flags &= ~CH_FCAR;
 778
 779         if (phys_carrier == 1)
 780                 ch->ch_flags |= CH_CD;
 781         else
 782                 ch->ch_flags &= ~CH_CD;
 783 }
 784
 785
 786 void jsm_check_queue_flow_control(struct jsm_channel *ch)
 787 {
 788         int qleft = 0;
 789
 790         /* Store how much space we have left in the queue */
 791         if ((qleft = ch->ch_r_tail - ch->ch_r_head - 1) < 0)
 792                 qleft += RQUEUEMASK + 1;
 793
 794         /*
 795          * Check to see if we should enforce flow control on our queue because
 796          * the ld (or user) isn't reading data out of our queue fast enuf.
 797          *
 798          * NOTE: This is done based on what the current flow control of the
 799          * port is set for.
 800          *
 801          * 1) HWFLOW (RTS) - Turn off the UART's Receive interrupt.
 802          *      This will cause the UART's FIFO to back up, and force
 803          *      the RTS signal to be dropped.
 804          * 2) SWFLOW (IXOFF) - Keep trying to send a stop character to
 805          *      the other side, in hopes it will stop sending data to us.
 806          * 3) NONE - Nothing we can do.  We will simply drop any extra data
 807          *      that gets sent into us when the queue fills up.
 808          */
 809         if (qleft < 256) {
 810                 /* HWFLOW */
 811                 if (ch->ch_c_cflag & CRTSCTS) {
 812                         if(!(ch->ch_flags & CH_RECEIVER_OFF)) {
 813                                 ch->ch_bd->bd_ops->disable_receiver(ch);
 814                                 ch->ch_flags |= (CH_RECEIVER_OFF);
 815                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 816                                         "Internal queue hit hilevel mark (%d)! Turning off interrupts.\n",
 817                                         qleft);
 818                         }
 819                 }
 820                 /* SWFLOW */
 821                 else if (ch->ch_c_iflag & IXOFF) {
 822                         if (ch->ch_stops_sent <= MAX_STOPS_SENT) {
 823                                 ch->ch_bd->bd_ops->send_stop_character(ch);
 824                                 ch->ch_stops_sent++;
 825                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 826                                         "Sending stop char! Times sent: %x\n", ch->ch_stops_sent);
 827                         }
 828                 }
 829         }
 830
 831         /*
 832          * Check to see if we should unenforce flow control because
 833          * ld (or user) finally read enuf data out of our queue.
 834          *
 835          * NOTE: This is done based on what the current flow control of the
 836          * port is set for.
 837          *
 838          * 1) HWFLOW (RTS) - Turn back on the UART's Receive interrupt.
 839          *      This will cause the UART's FIFO to raise RTS back up,
 840          *      which will allow the other side to start sending data again.
 841          * 2) SWFLOW (IXOFF) - Send a start character to
 842          *      the other side, so it will start sending data to us again.
 843          * 3) NONE - Do nothing. Since we didn't do anything to turn off the
 844          *      other side, we don't need to do anything now.
 845          */
 846         if (qleft > (RQUEUESIZE / 2)) {
 847                 /* HWFLOW */
 848                 if (ch->ch_c_cflag & CRTSCTS) {
 849                         if (ch->ch_flags & CH_RECEIVER_OFF) {
 850                                 ch->ch_bd->bd_ops->enable_receiver(ch);
 851                                 ch->ch_flags &= ~(CH_RECEIVER_OFF);
 852                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 853                                         "Internal queue hit lowlevel mark (%d)! Turning on interrupts.\n",
 854                                         qleft);
 855                         }
 856                 }
 857                 /* SWFLOW */
 858                 else if (ch->ch_c_iflag & IXOFF && ch->ch_stops_sent) {
 859                         ch->ch_stops_sent = 0;
 860                         ch->ch_bd->bd_ops->send_start_character(ch);
 861                         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "Sending start char!\n");
 862                 }
 863         }
 864 }
 865
 866 /*
 867  * jsm_tty_write()
 868  *
 869  * Take data from the user or kernel and send it out to the FEP.
 870  * In here exists all the Transparent Print magic as well.
 871  */
 872 int jsm_tty_write(struct uart_port *port)
 873 {
 874         int bufcount = 0, n = 0;
 875         int data_count = 0,data_count1 =0;
 876         u16 head;
 877         u16 tail;
 878         u16 tmask;
 879         u32 remain;
 880         int temp_tail = port->info->xmit.tail;
 881         struct jsm_channel *channel = (struct jsm_channel *)port;
 882
 883         tmask = WQUEUEMASK;
 884         head = (channel->ch_w_head) & tmask;
 885         tail = (channel->ch_w_tail) & tmask;
 886
 887         if ((bufcount = tail - head - 1) < 0)
 888                 bufcount += WQUEUESIZE;
 889
 890         n = bufcount;
 891
 892         n = min(n, 56);
 893         remain = WQUEUESIZE - head;
 894
 895         data_count = 0;
 896         if (n >= remain) {
 897                 n -= remain;
 898                 while ((port->info->xmit.head != temp_tail) &&
 899                 (data_count < remain)) {
 900                         channel->ch_wqueue[head++] =
 901                         port->info->xmit.buf[temp_tail];
 902
 903                         temp_tail++;
 904                         temp_tail &= (UART_XMIT_SIZE - 1);
 905                         data_count++;
 906                 }
 907                 if (data_count == remain) head = 0;
 908         }
 909
 910         data_count1 = 0;
 911         if (n > 0) {
 912                 remain = n;
 913                 while ((port->info->xmit.head != temp_tail) &&
 914                         (data_count1 < remain)) {
 915                         channel->ch_wqueue[head++] =
 916                                 port->info->xmit.buf[temp_tail];
 917
 918                         temp_tail++;
 919                         temp_tail &= (UART_XMIT_SIZE - 1);
 920                         data_count1++;
 921
 922                 }
 923         }
 924
 925         port->info->xmit.tail = temp_tail;
 926
 927         data_count += data_count1;
 928         if (data_count) {
 929                 head &= tmask;
 930                 channel->ch_w_head = head;
 931         }
 932
 933         if (data_count) {
 934                 channel->ch_bd->bd_ops->copy_data_from_queue_to_uart(channel);
 935         }
 936
 937         return data_count;
 938 }