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  * Wendy Xiong   <wendyx@us.ltcfwd.linux.ibm.com>
  24  *
  25  ***********************************************************************/
  26 #include <linux/tty.h>
  27 #include <linux/tty_flip.h>
  28 #include <linux/serial_reg.h>
  29 #include <linux/delay.h>        /* For udelay */
  30 #include <linux/pci.h>
  31
  32 #include "jsm.h"
  33
  34 static void jsm_carrier(struct jsm_channel *ch);
  35
  36 static inline int jsm_get_mstat(struct jsm_channel *ch)
  37 {
  38         unsigned char mstat;
  39         unsigned result;
  40
  41         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "start\n");
  42
  43         mstat = (ch->ch_mostat | ch->ch_mistat);
  44
  45         result = 0;
  46
  47         if (mstat & UART_MCR_DTR)
  48                 result |= TIOCM_DTR;
  49         if (mstat & UART_MCR_RTS)
  50                 result |= TIOCM_RTS;
  51         if (mstat & UART_MSR_CTS)
  52                 result |= TIOCM_CTS;
  53         if (mstat & UART_MSR_DSR)
  54                 result |= TIOCM_DSR;
  55         if (mstat & UART_MSR_RI)
  56                 result |= TIOCM_RI;
  57         if (mstat & UART_MSR_DCD)
  58                 result |= TIOCM_CD;
  59
  60         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "finish\n");
  61         return result;
  62 }
  63
  64 static unsigned int jsm_tty_tx_empty(struct uart_port *port)
  65 {
  66         return TIOCSER_TEMT;
  67 }
  68
  69 /*
  70  * Return modem signals to ld.
  71  */
  72 static unsigned int jsm_tty_get_mctrl(struct uart_port *port)
  73 {
  74         int result;
  75         struct jsm_channel *channel = (struct jsm_channel *)port;
  76
  77         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
  78
  79         result = jsm_get_mstat(channel);
  80
  81         if (result < 0)
  82                 return -ENXIO;
  83
  84         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
  85
  86         return result;
  87 }
  88
  89 /*
  90  * jsm_set_modem_info()
  91  *
  92  * Set modem signals, called by ld.
  93  */
  94 static void jsm_tty_set_mctrl(struct uart_port *port, unsigned int mctrl)
  95 {
  96         struct jsm_channel *channel = (struct jsm_channel *)port;
  97
  98         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
  99
 100         if (mctrl & TIOCM_RTS)
 101                 channel->ch_mostat |= UART_MCR_RTS;
 102         else
 103                 channel->ch_mostat &= ~UART_MCR_RTS;
 104
 105         if (mctrl & TIOCM_DTR)
 106                 channel->ch_mostat |= UART_MCR_DTR;
 107         else
 108                 channel->ch_mostat &= ~UART_MCR_DTR;
 109
 110         channel->ch_bd->bd_ops->assert_modem_signals(channel);
 111
 112         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
 113         udelay(10);
 114 }
 115
 116 static void jsm_tty_start_tx(struct uart_port *port)
 117 {
 118         struct jsm_channel *channel = (struct jsm_channel *)port;
 119
 120         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
 121
 122         channel->ch_flags &= ~(CH_STOP);
 123         jsm_tty_write(port);
 124
 125         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
 126 }
 127
 128 static void jsm_tty_stop_tx(struct uart_port *port)
 129 {
 130         struct jsm_channel *channel = (struct jsm_channel *)port;
 131
 132         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n");
 133
 134         channel->ch_flags |= (CH_STOP);
 135
 136         jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n");
 137 }
 138
 139 static void jsm_tty_send_xchar(struct uart_port *port, char ch)
 140 {
 141         unsigned long lock_flags;
 142         struct jsm_channel *channel = (struct jsm_channel *)port;
 143
 144         spin_lock_irqsave(&port->lock, lock_flags);
 145         if (ch == port->info->tty->termios->c_cc[VSTART])
 146                 channel->ch_bd->bd_ops->send_start_character(channel);
 147
 148         if (ch == port->info->tty->termios->c_cc[VSTOP])
 149                 channel->ch_bd->bd_ops->send_stop_character(channel);
 150         spin_unlock_irqrestore(&port->lock, lock_flags);
 151 }
 152
 153 static void jsm_tty_stop_rx(struct uart_port *port)
 154 {
 155         struct jsm_channel *channel = (struct jsm_channel *)port;
 156
 157         channel->ch_bd->bd_ops->disable_receiver(channel);
 158 }
 159
 160 static void jsm_tty_break(struct uart_port *port, int break_state)
 161 {
 162         unsigned long lock_flags;
 163         struct jsm_channel *channel = (struct jsm_channel *)port;
 164
 165         spin_lock_irqsave(&port->lock, lock_flags);
 166         if (break_state == -1)
 167                 channel->ch_bd->bd_ops->send_break(channel);
 168         else
 169                 channel->ch_bd->bd_ops->clear_break(channel, 0);
 170
 171         spin_unlock_irqrestore(&port->lock, lock_flags);
 172 }
 173
 174 static int jsm_tty_open(struct uart_port *port)
 175 {
 176         struct jsm_board *brd;
 177         int rc = 0;
 178         struct jsm_channel *channel = (struct jsm_channel *)port;
 179
 180         /* Get board pointer from our array of majors we have allocated */
 181         brd = channel->ch_bd;
 182
 183         /*
 184          * Allocate channel buffers for read/write/error.
 185          * Set flag, so we don't get trounced on.
 186          */
 187         channel->ch_flags |= (CH_OPENING);
 188
 189         /* Drop locks, as malloc with GFP_KERNEL can sleep */
 190
 191         if (!channel->ch_rqueue) {
 192                 channel->ch_rqueue = (u8 *) kmalloc(RQUEUESIZE, GFP_KERNEL);
 193                 if (!channel->ch_rqueue) {
 194                         jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
 195                                 "unable to allocate read queue buf");
 196                         return -ENOMEM;
 197                 }
 198                 memset(channel->ch_rqueue, 0, RQUEUESIZE);
 199         }
 200         if (!channel->ch_equeue) {
 201                 channel->ch_equeue = (u8 *) kmalloc(EQUEUESIZE, GFP_KERNEL);
 202                 if (!channel->ch_equeue) {
 203                         jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
 204                                 "unable to allocate error queue buf");
 205                         return -ENOMEM;
 206                 }
 207                 memset(channel->ch_equeue, 0, EQUEUESIZE);
 208         }
 209         if (!channel->ch_wqueue) {
 210                 channel->ch_wqueue = (u8 *) kmalloc(WQUEUESIZE, GFP_KERNEL);
 211                 if (!channel->ch_wqueue) {
 212                         jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev,
 213                                 "unable to allocate write queue buf");
 214                         return -ENOMEM;
 215                 }
 216                 memset(channel->ch_wqueue, 0, WQUEUESIZE);
 217         }
 218
 219         channel->ch_flags &= ~(CH_OPENING);
 220         /*
 221          * Initialize if neither terminal is open.
 222          */
 223         jsm_printk(OPEN, INFO, &channel->ch_bd->pci_dev,
 224                 "jsm_open: initializing channel in open...\n");
 225
 226         /*
 227          * Flush input queues.
 228          */
 229         channel->ch_r_head = channel->ch_r_tail = 0;
 230         channel->ch_e_head = channel->ch_e_tail = 0;
 231         channel->ch_w_head = channel->ch_w_tail = 0;
 232
 233         brd->bd_ops->flush_uart_write(channel);
 234         brd->bd_ops->flush_uart_read(channel);
 235
 236         channel->ch_flags = 0;
 237         channel->ch_cached_lsr = 0;
 238         channel->ch_stops_sent = 0;
 239
 240         channel->ch_c_cflag     = port->info->tty->termios->c_cflag;
 241         channel->ch_c_iflag     = port->info->tty->termios->c_iflag;
 242         channel->ch_c_oflag     = port->info->tty->termios->c_oflag;
 243         channel->ch_c_lflag     = port->info->tty->termios->c_lflag;
 244         channel->ch_startc = port->info->tty->termios->c_cc[VSTART];
 245         channel->ch_stopc = port->info->tty->termios->c_cc[VSTOP];
 246
 247         /* Tell UART to init itself */
 248         brd->bd_ops->uart_init(channel);
 249
 250         /*
 251          * Run param in case we changed anything
 252          */
 253         brd->bd_ops->param(channel);
 254
 255         jsm_carrier(channel);
 256
 257         channel->ch_open_count++;
 258
 259         jsm_printk(OPEN, INFO, &channel->ch_bd->pci_dev, "finish\n");
 260         return rc;
 261 }
 262
 263 static void jsm_tty_close(struct uart_port *port)
 264 {
 265         struct jsm_board *bd;
 266         struct termios *ts;
 267         struct jsm_channel *channel = (struct jsm_channel *)port;
 268
 269         jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev, "start\n");
 270
 271         bd = channel->ch_bd;
 272         ts = channel->uart_port.info->tty->termios;
 273
 274         channel->ch_flags &= ~(CH_STOPI);
 275
 276         channel->ch_open_count--;
 277
 278         /*
 279          * If we have HUPCL set, lower DTR and RTS
 280          */
 281         if (channel->ch_c_cflag & HUPCL) {
 282                 jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev,
 283                         "Close. HUPCL set, dropping DTR/RTS\n");
 284
 285                 /* Drop RTS/DTR */
 286                 channel->ch_mostat &= ~(UART_MCR_DTR | UART_MCR_RTS);
 287                 bd->bd_ops->assert_modem_signals(channel);
 288         }
 289
 290         channel->ch_old_baud = 0;
 291
 292         /* Turn off UART interrupts for this port */
 293         channel->ch_bd->bd_ops->uart_off(channel);
 294
 295         jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev, "finish\n");
 296 }
 297
 298 static void jsm_tty_set_termios(struct uart_port *port,
 299                                  struct termios *termios,
 300                                  struct termios *old_termios)
 301 {
 302         unsigned long lock_flags;
 303         struct jsm_channel *channel = (struct jsm_channel *)port;
 304
 305         spin_lock_irqsave(&port->lock, lock_flags);
 306         channel->ch_c_cflag     = termios->c_cflag;
 307         channel->ch_c_iflag     = termios->c_iflag;
 308         channel->ch_c_oflag     = termios->c_oflag;
 309         channel->ch_c_lflag     = termios->c_lflag;
 310         channel->ch_startc      = termios->c_cc[VSTART];
 311         channel->ch_stopc       = termios->c_cc[VSTOP];
 312
 313         channel->ch_bd->bd_ops->param(channel);
 314         jsm_carrier(channel);
 315         spin_unlock_irqrestore(&port->lock, lock_flags);
 316 }
 317
 318 static const char *jsm_tty_type(struct uart_port *port)
 319 {
 320         return "jsm";
 321 }
 322
 323 static void jsm_tty_release_port(struct uart_port *port)
 324 {
 325 }
 326
 327 static int jsm_tty_request_port(struct uart_port *port)
 328 {
 329         return 0;
 330 }
 331
 332 static void jsm_config_port(struct uart_port *port, int flags)
 333 {
 334         port->type = PORT_JSM;
 335 }
 336
 337 static struct uart_ops jsm_ops = {
 338         .tx_empty       = jsm_tty_tx_empty,
 339         .set_mctrl      = jsm_tty_set_mctrl,
 340         .get_mctrl      = jsm_tty_get_mctrl,
 341         .stop_tx        = jsm_tty_stop_tx,
 342         .start_tx       = jsm_tty_start_tx,
 343         .send_xchar     = jsm_tty_send_xchar,
 344         .stop_rx        = jsm_tty_stop_rx,
 345         .break_ctl      = jsm_tty_break,
 346         .startup        = jsm_tty_open,
 347         .shutdown       = jsm_tty_close,
 348         .set_termios    = jsm_tty_set_termios,
 349         .type           = jsm_tty_type,
 350         .release_port   = jsm_tty_release_port,
 351         .request_port   = jsm_tty_request_port,
 352         .config_port    = jsm_config_port,
 353 };
 354
 355 /*
 356  * jsm_tty_init()
 357  *
 358  * Init the tty subsystem.  Called once per board after board has been
 359  * downloaded and init'ed.
 360  */
 361 int jsm_tty_init(struct jsm_board *brd)
 362 {
 363         int i;
 364         void __iomem *vaddr;
 365         struct jsm_channel *ch;
 366
 367         if (!brd)
 368                 return -ENXIO;
 369
 370         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 371
 372         /*
 373          * Initialize board structure elements.
 374          */
 375
 376         brd->nasync = brd->maxports;
 377
 378         /*
 379          * Allocate channel memory that might not have been allocated
 380          * when the driver was first loaded.
 381          */
 382         for (i = 0; i < brd->nasync; i++) {
 383                 if (!brd->channels[i]) {
 384
 385                         /*
 386                          * Okay to malloc with GFP_KERNEL, we are not at
 387                          * interrupt context, and there are no locks held.
 388                          */
 389                         brd->channels[i] = kmalloc(sizeof(struct jsm_channel), GFP_KERNEL);
 390                         if (!brd->channels[i]) {
 391                                 jsm_printk(CORE, ERR, &brd->pci_dev,
 392                                         "%s:%d Unable to allocate memory for channel struct\n",
 393                                                          __FILE__, __LINE__);
 394                         }
 395                         memset(brd->channels[i], 0, sizeof(struct jsm_channel));
 396                 }
 397         }
 398
 399         ch = brd->channels[0];
 400         vaddr = brd->re_map_membase;
 401
 402         /* Set up channel variables */
 403         for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
 404
 405                 if (!brd->channels[i])
 406                         continue;
 407
 408                 spin_lock_init(&ch->ch_lock);
 409
 410                 if (brd->bd_uart_offset == 0x200)
 411                         ch->ch_neo_uart =  vaddr + (brd->bd_uart_offset * i);
 412
 413                 ch->ch_bd = brd;
 414                 ch->ch_portnum = i;
 415
 416                 /* .25 second delay */
 417                 ch->ch_close_delay = 250;
 418
 419                 init_waitqueue_head(&ch->ch_flags_wait);
 420         }
 421
 422         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 423         return 0;
 424 }
 425
 426 int jsm_uart_port_init(struct jsm_board *brd)
 427 {
 428         int i;
 429         struct jsm_channel *ch;
 430
 431         if (!brd)
 432                 return -ENXIO;
 433
 434         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 435
 436         /*
 437          * Initialize board structure elements.
 438          */
 439
 440         brd->nasync = brd->maxports;
 441
 442         /* Set up channel variables */
 443         for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) {
 444
 445                 if (!brd->channels[i])
 446                         continue;
 447
 448                 brd->channels[i]->uart_port.irq = brd->irq;
 449                 brd->channels[i]->uart_port.type = PORT_JSM;
 450                 brd->channels[i]->uart_port.iotype = UPIO_MEM;
 451                 brd->channels[i]->uart_port.membase = brd->re_map_membase;
 452                 brd->channels[i]->uart_port.fifosize = 16;
 453                 brd->channels[i]->uart_port.ops = &jsm_ops;
 454                 brd->channels[i]->uart_port.line = brd->channels[i]->ch_portnum + brd->boardnum * 2;
 455                 if (uart_add_one_port (&jsm_uart_driver, &brd->channels[i]->uart_port))
 456                         printk(KERN_INFO "Added device failed\n");
 457                 else
 458                         printk(KERN_INFO "Added device \n");
 459         }
 460
 461         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 462         return 0;
 463 }
 464
 465 int jsm_remove_uart_port(struct jsm_board *brd)
 466 {
 467         int i;
 468         struct jsm_channel *ch;
 469
 470         if (!brd)
 471                 return -ENXIO;
 472
 473         jsm_printk(INIT, INFO, &brd->pci_dev, "start\n");
 474
 475         /*
 476          * Initialize board structure elements.
 477          */
 478
 479         brd->nasync = brd->maxports;
 480
 481         /* Set up channel variables */
 482         for (i = 0; i < brd->nasync; i++) {
 483
 484                 if (!brd->channels[i])
 485                         continue;
 486
 487                 ch = brd->channels[i];
 488
 489                 uart_remove_one_port(&jsm_uart_driver, &brd->channels[i]->uart_port);
 490         }
 491
 492         jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n");
 493         return 0;
 494 }
 495
 496 void jsm_input(struct jsm_channel *ch)
 497 {
 498         struct jsm_board *bd;
 499         struct tty_struct *tp;
 500         u32 rmask;
 501         u16 head;
 502         u16 tail;
 503         int data_len;
 504         unsigned long lock_flags;
 505         int flip_len;
 506         int len = 0;
 507         int n = 0;
 508         char *buf = NULL;
 509         char *buf2 = NULL;
 510         int s = 0;
 511         int i = 0;
 512
 513         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n");
 514
 515         if (!ch)
 516                 return;
 517
 518         tp = ch->uart_port.info->tty;
 519
 520         bd = ch->ch_bd;
 521         if(!bd)
 522                 return;
 523
 524         spin_lock_irqsave(&ch->ch_lock, lock_flags);
 525
 526         /*
 527          *Figure the number of characters in the buffer.
 528          *Exit immediately if none.
 529          */
 530
 531         rmask = RQUEUEMASK;
 532
 533         head = ch->ch_r_head & rmask;
 534         tail = ch->ch_r_tail & rmask;
 535
 536         data_len = (head - tail) & rmask;
 537         if (data_len == 0) {
 538                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 539                 return;
 540         }
 541
 542         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n");
 543
 544         /*
 545          *If the device is not open, or CREAD is off, flush
 546          *input data and return immediately.
 547          */
 548         if (!tp ||
 549                 !(tp->termios->c_cflag & CREAD) ) {
 550
 551                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 552                         "input. dropping %d bytes on port %d...\n", data_len, ch->ch_portnum);
 553                 ch->ch_r_head = tail;
 554
 555                 /* Force queue flow control to be released, if needed */
 556                 jsm_check_queue_flow_control(ch);
 557
 558                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 559                 return;
 560         }
 561
 562         /*
 563          * If we are throttled, simply don't read any data.
 564          */
 565         if (ch->ch_flags & CH_STOPI) {
 566                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 567                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 568                         "Port %d throttled, not reading any data. head: %x tail: %x\n",
 569                         ch->ch_portnum, head, tail);
 570                 return;
 571         }
 572
 573         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start 2\n");
 574
 575         /*
 576          * If the rxbuf is empty and we are not throttled, put as much
 577          * as we can directly into the linux TTY flip buffer.
 578          * The jsm_rawreadok case takes advantage of carnal knowledge that
 579          * the char_buf and the flag_buf are next to each other and
 580          * are each of (2 * TTY_FLIPBUF_SIZE) size.
 581          *
 582          * NOTE: if(!tty->real_raw), the call to ldisc.receive_buf
 583          *actually still uses the flag buffer, so you can't
 584          *use it for input data
 585          */
 586         if (jsm_rawreadok) {
 587                 if (tp->real_raw)
 588                         flip_len = MYFLIPLEN;
 589                 else
 590                         flip_len = 2 * TTY_FLIPBUF_SIZE;
 591         } else
 592                 flip_len = TTY_FLIPBUF_SIZE - tp->flip.count;
 593
 594         len = min(data_len, flip_len);
 595         len = min(len, (N_TTY_BUF_SIZE - 1) - tp->read_cnt);
 596
 597         if (len <= 0) {
 598                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 599                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "jsm_input 1\n");
 600                 return;
 601         }
 602
 603         /*
 604          * If we're bypassing flip buffers on rx, we can blast it
 605          * right into the beginning of the buffer.
 606          */
 607         if (jsm_rawreadok) {
 608                 if (tp->real_raw) {
 609                         if (ch->ch_flags & CH_FLIPBUF_IN_USE) {
 610                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 611                                         "JSM - FLIPBUF in use. delaying input\n");
 612                                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 613                                 return;
 614                         }
 615                         ch->ch_flags |= CH_FLIPBUF_IN_USE;
 616                         buf = ch->ch_bd->flipbuf;
 617                         buf2 = NULL;
 618                 } else {
 619                         buf = tp->flip.char_buf;
 620                         buf2 = tp->flip.flag_buf;
 621                 }
 622         } else {
 623                 buf = tp->flip.char_buf_ptr;
 624                 buf2 = tp->flip.flag_buf_ptr;
 625         }
 626
 627         n = len;
 628
 629         /*
 630          * n now contains the most amount of data we can copy,
 631          * bounded either by the flip buffer size or the amount
 632          * of data the card actually has pending...
 633          */
 634         while (n) {
 635                 s = ((head >= tail) ? head : RQUEUESIZE) - tail;
 636                 s = min(s, n);
 637
 638                 if (s <= 0)
 639                         break;
 640
 641                 memcpy(buf, ch->ch_rqueue + tail, s);
 642
 643                 /* buf2 is only set when port isn't raw */
 644                 if (buf2)
 645                         memcpy(buf2, ch->ch_equeue + tail, s);
 646
 647                 tail += s;
 648                 buf += s;
 649                 if (buf2)
 650                         buf2 += s;
 651                 n -= s;
 652                 /* Flip queue if needed */
 653                 tail &= rmask;
 654         }
 655
 656         /*
 657          * In high performance mode, we don't have to update
 658          * flag_buf or any of the counts or pointers into flip buf.
 659          */
 660         if (!jsm_rawreadok) {
 661                 if (I_PARMRK(tp) || I_BRKINT(tp) || I_INPCK(tp)) {
 662                         for (i = 0; i < len; i++) {
 663                                 /*
 664                                  * Give the Linux ld the flags in the
 665                                  * format it likes.
 666                                  */
 667                                 if (tp->flip.flag_buf_ptr[i] & UART_LSR_BI)
 668                                         tp->flip.flag_buf_ptr[i] = TTY_BREAK;
 669                                 else if (tp->flip.flag_buf_ptr[i] & UART_LSR_PE)
 670                                         tp->flip.flag_buf_ptr[i] = TTY_PARITY;
 671                                 else if (tp->flip.flag_buf_ptr[i] & UART_LSR_FE)
 672                                         tp->flip.flag_buf_ptr[i] = TTY_FRAME;
 673                                 else
 674                                         tp->flip.flag_buf_ptr[i] = TTY_NORMAL;
 675                         }
 676                 } else {
 677                         memset(tp->flip.flag_buf_ptr, 0, len);
 678                 }
 679
 680                 tp->flip.char_buf_ptr += len;
 681                 tp->flip.flag_buf_ptr += len;
 682                 tp->flip.count += len;
 683         }
 684         else if (!tp->real_raw) {
 685                 if (I_PARMRK(tp) || I_BRKINT(tp) || I_INPCK(tp)) {
 686                         for (i = 0; i < len; i++) {
 687                                 /*
 688                                  * Give the Linux ld the flags in the
 689                                  * format it likes.
 690                                  */
 691                                 if (tp->flip.flag_buf_ptr[i] & UART_LSR_BI)
 692                                         tp->flip.flag_buf_ptr[i] = TTY_BREAK;
 693                                 else if (tp->flip.flag_buf_ptr[i] & UART_LSR_PE)
 694                                         tp->flip.flag_buf_ptr[i] = TTY_PARITY;
 695                                 else if (tp->flip.flag_buf_ptr[i] & UART_LSR_FE)
 696                                         tp->flip.flag_buf_ptr[i] = TTY_FRAME;
 697                                 else
 698                                         tp->flip.flag_buf_ptr[i] = TTY_NORMAL;
 699                         }
 700                 } else
 701                         memset(tp->flip.flag_buf, 0, len);
 702         }
 703
 704         /*
 705          * If we're doing raw reads, jam it right into the
 706          * line disc bypassing the flip buffers.
 707          */
 708         if (jsm_rawreadok) {
 709                 if (tp->real_raw) {
 710                         ch->ch_r_tail = tail & rmask;
 711                         ch->ch_e_tail = tail & rmask;
 712
 713                         jsm_check_queue_flow_control(ch);
 714
 715                         /* !!! WE *MUST* LET GO OF ALL LOCKS BEFORE CALLING RECEIVE BUF !!! */
 716
 717                         spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 718
 719                         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 720                                 "jsm_input. %d real_raw len:%d calling receive_buf for board %d\n",
 721                                 __LINE__, len, ch->ch_bd->boardnum);
 722                         tp->ldisc.receive_buf(tp, ch->ch_bd->flipbuf, NULL, len);
 723
 724                         /* Allow use of channel flip buffer again */
 725                         spin_lock_irqsave(&ch->ch_lock, lock_flags);
 726                         ch->ch_flags &= ~CH_FLIPBUF_IN_USE;
 727                         spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 728
 729                 } else {
 730                         ch->ch_r_tail = tail & rmask;
 731                         ch->ch_e_tail = tail & rmask;
 732
 733                         jsm_check_queue_flow_control(ch);
 734
 735                         /* !!! WE *MUST* LET GO OF ALL LOCKS BEFORE CALLING RECEIVE BUF !!! */
 736                         spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 737
 738                         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 739                                 "jsm_input. %d not real_raw len:%d calling receive_buf for board %d\n",
 740                                 __LINE__, len, ch->ch_bd->boardnum);
 741
 742                         tp->ldisc.receive_buf(tp, tp->flip.char_buf, tp->flip.flag_buf, len);
 743                 }
 744         } else {
 745                 ch->ch_r_tail = tail & rmask;
 746                 ch->ch_e_tail = tail & rmask;
 747
 748                 jsm_check_queue_flow_control(ch);
 749
 750                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 751
 752                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 753                         "jsm_input. %d not jsm_read raw okay scheduling flip\n", __LINE__);
 754                 tty_schedule_flip(tp);
 755         }
 756
 757         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "finish\n");
 758 }
 759
 760 static void jsm_carrier(struct jsm_channel *ch)
 761 {
 762         struct jsm_board *bd;
 763
 764         int virt_carrier = 0;
 765         int phys_carrier = 0;
 766
 767         jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev, "start\n");
 768         if (!ch)
 769                 return;
 770
 771         bd = ch->ch_bd;
 772
 773         if (!bd)
 774                 return;
 775
 776         if (ch->ch_mistat & UART_MSR_DCD) {
 777                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 778                         "mistat: %x D_CD: %x\n", ch->ch_mistat, ch->ch_mistat & UART_MSR_DCD);
 779                 phys_carrier = 1;
 780         }
 781
 782         if (ch->ch_c_cflag & CLOCAL)
 783                 virt_carrier = 1;
 784
 785         jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 786                 "DCD: physical: %d virt: %d\n", phys_carrier, virt_carrier);
 787
 788         /*
 789          * Test for a VIRTUAL carrier transition to HIGH.
 790          */
 791         if (((ch->ch_flags & CH_FCAR) == 0) && (virt_carrier == 1)) {
 792
 793                 /*
 794                  * When carrier rises, wake any threads waiting
 795                  * for carrier in the open routine.
 796                  */
 797
 798                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 799                         "carrier: virt DCD rose\n");
 800
 801                 if (waitqueue_active(&(ch->ch_flags_wait)))
 802                         wake_up_interruptible(&ch->ch_flags_wait);
 803         }
 804
 805         /*
 806          * Test for a PHYSICAL carrier transition to HIGH.
 807          */
 808         if (((ch->ch_flags & CH_CD) == 0) && (phys_carrier == 1)) {
 809
 810                 /*
 811                  * When carrier rises, wake any threads waiting
 812                  * for carrier in the open routine.
 813                  */
 814
 815                 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev,
 816                         "carrier: physical DCD rose\n");
 817
 818                 if (waitqueue_active(&(ch->ch_flags_wait)))
 819                         wake_up_interruptible(&ch->ch_flags_wait);
 820         }
 821
 822         /*
 823          *  Test for a PHYSICAL transition to low, so long as we aren't
 824          *  currently ignoring physical transitions (which is what "virtual
 825          *  carrier" indicates).
 826          *
 827          *  The transition of the virtual carrier to low really doesn't
 828          *  matter... it really only means "ignore carrier state", not
 829          *  "make pretend that carrier is there".
 830          */
 831         if ((virt_carrier == 0) && ((ch->ch_flags & CH_CD) != 0)
 832                         && (phys_carrier == 0)) {
 833                 /*
 834                  *      When carrier drops:
 835                  *
 836                  *      Drop carrier on all open units.
 837                  *
 838                  *      Flush queues, waking up any task waiting in the
 839                  *      line discipline.
 840                  *
 841                  *      Send a hangup to the control terminal.
 842                  *
 843                  *      Enable all select calls.
 844                  */
 845                 if (waitqueue_active(&(ch->ch_flags_wait)))
 846                         wake_up_interruptible(&ch->ch_flags_wait);
 847         }
 848
 849         /*
 850          *  Make sure that our cached values reflect the current reality.
 851          */
 852         if (virt_carrier == 1)
 853                 ch->ch_flags |= CH_FCAR;
 854         else
 855                 ch->ch_flags &= ~CH_FCAR;
 856
 857         if (phys_carrier == 1)
 858                 ch->ch_flags |= CH_CD;
 859         else
 860                 ch->ch_flags &= ~CH_CD;
 861 }
 862
 863
 864 void jsm_check_queue_flow_control(struct jsm_channel *ch)
 865 {
 866         int qleft = 0;
 867
 868         /* Store how much space we have left in the queue */
 869         if ((qleft = ch->ch_r_tail - ch->ch_r_head - 1) < 0)
 870                 qleft += RQUEUEMASK + 1;
 871
 872         /*
 873          * Check to see if we should enforce flow control on our queue because
 874          * the ld (or user) isn't reading data out of our queue fast enuf.
 875          *
 876          * NOTE: This is done based on what the current flow control of the
 877          * port is set for.
 878          *
 879          * 1) HWFLOW (RTS) - Turn off the UART's Receive interrupt.
 880          *      This will cause the UART's FIFO to back up, and force
 881          *      the RTS signal to be dropped.
 882          * 2) SWFLOW (IXOFF) - Keep trying to send a stop character to
 883          *      the other side, in hopes it will stop sending data to us.
 884          * 3) NONE - Nothing we can do.  We will simply drop any extra data
 885          *      that gets sent into us when the queue fills up.
 886          */
 887         if (qleft < 256) {
 888                 /* HWFLOW */
 889                 if (ch->ch_c_cflag & CRTSCTS) {
 890                         if(!(ch->ch_flags & CH_RECEIVER_OFF)) {
 891                                 ch->ch_bd->bd_ops->disable_receiver(ch);
 892                                 ch->ch_flags |= (CH_RECEIVER_OFF);
 893                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 894                                         "Internal queue hit hilevel mark (%d)! Turning off interrupts.\n",
 895                                         qleft);
 896                         }
 897                 }
 898                 /* SWFLOW */
 899                 else if (ch->ch_c_iflag & IXOFF) {
 900                         if (ch->ch_stops_sent <= MAX_STOPS_SENT) {
 901                                 ch->ch_bd->bd_ops->send_stop_character(ch);
 902                                 ch->ch_stops_sent++;
 903                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 904                                         "Sending stop char! Times sent: %x\n", ch->ch_stops_sent);
 905                         }
 906                 }
 907         }
 908
 909         /*
 910          * Check to see if we should unenforce flow control because
 911          * ld (or user) finally read enuf data out of our queue.
 912          *
 913          * NOTE: This is done based on what the current flow control of the
 914          * port is set for.
 915          *
 916          * 1) HWFLOW (RTS) - Turn back on the UART's Receive interrupt.
 917          *      This will cause the UART's FIFO to raise RTS back up,
 918          *      which will allow the other side to start sending data again.
 919          * 2) SWFLOW (IXOFF) - Send a start character to
 920          *      the other side, so it will start sending data to us again.
 921          * 3) NONE - Do nothing. Since we didn't do anything to turn off the
 922          *      other side, we don't need to do anything now.
 923          */
 924         if (qleft > (RQUEUESIZE / 2)) {
 925                 /* HWFLOW */
 926                 if (ch->ch_c_cflag & CRTSCTS) {
 927                         if (ch->ch_flags & CH_RECEIVER_OFF) {
 928                                 ch->ch_bd->bd_ops->enable_receiver(ch);
 929                                 ch->ch_flags &= ~(CH_RECEIVER_OFF);
 930                                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 931                                         "Internal queue hit lowlevel mark (%d)! Turning on interrupts.\n",
 932                                         qleft);
 933                         }
 934                 }
 935                 /* SWFLOW */
 936                 else if (ch->ch_c_iflag & IXOFF && ch->ch_stops_sent) {
 937                         ch->ch_stops_sent = 0;
 938                         ch->ch_bd->bd_ops->send_start_character(ch);
 939                         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "Sending start char!\n");
 940                 }
 941         }
 942 }
 943
 944 /*
 945  * jsm_tty_write()
 946  *
 947  * Take data from the user or kernel and send it out to the FEP.
 948  * In here exists all the Transparent Print magic as well.
 949  */
 950 int jsm_tty_write(struct uart_port *port)
 951 {
 952         int bufcount = 0, n = 0;
 953         int data_count = 0,data_count1 =0;
 954         u16 head;
 955         u16 tail;
 956         u16 tmask;
 957         u32 remain;
 958         int temp_tail = port->info->xmit.tail;
 959         struct jsm_channel *channel = (struct jsm_channel *)port;
 960
 961         tmask = WQUEUEMASK;
 962         head = (channel->ch_w_head) & tmask;
 963         tail = (channel->ch_w_tail) & tmask;
 964
 965         if ((bufcount = tail - head - 1) < 0)
 966                 bufcount += WQUEUESIZE;
 967
 968         n = bufcount;
 969
 970         n = min(n, 56);
 971         remain = WQUEUESIZE - head;
 972
 973         data_count = 0;
 974         if (n >= remain) {
 975                 n -= remain;
 976                 while ((port->info->xmit.head != temp_tail) &&
 977                 (data_count < remain)) {
 978                         channel->ch_wqueue[head++] =
 979                         port->info->xmit.buf[temp_tail];
 980
 981                         temp_tail++;
 982                         temp_tail &= (UART_XMIT_SIZE - 1);
 983                         data_count++;
 984                 }
 985                 if (data_count == remain) head = 0;
 986         }
 987
 988         data_count1 = 0;
 989         if (n > 0) {
 990                 remain = n;
 991                 while ((port->info->xmit.head != temp_tail) &&
 992                         (data_count1 < remain)) {
 993                         channel->ch_wqueue[head++] =
 994                                 port->info->xmit.buf[temp_tail];
 995
 996                         temp_tail++;
 997                         temp_tail &= (UART_XMIT_SIZE - 1);
 998                         data_count1++;
 999
1000                 }
1001         }
1002
1003         port->info->xmit.tail = temp_tail;
1004
1005         data_count += data_count1;
1006         if (data_count) {
1007                 head &= tmask;
1008                 channel->ch_w_head = head;
1009         }
1010
1011         if (data_count) {
1012                 channel->ch_bd->bd_ops->copy_data_from_queue_to_uart(channel);
1013         }
1014
1015         return data_count;
1016 }