1 /************************************************************************ 2 * Copyright 2003 Digi International (www.digi.com) 3 * 4 * Copyright (C) 2004 IBM Corporation. All rights reserved. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2, or (at your option) 9 * any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED; without even the 13 * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 14 * PURPOSE. See the GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 59 * Temple Place - Suite 330, Boston, 19 * MA 02111-1307, USA. 20 * 21 * Contact Information: 22 * Scott H Kilau <Scott_Kilau@digi.com> 23 * Ananda Venkatarman <mansarov@us.ibm.com> 24 * Modifications: 25 * 01/19/06: changed jsm_input routine to use the dynamically allocated 26 * tty_buffer changes. Contributors: Scott Kilau and Ananda V. 27 ***********************************************************************/ 28 #include <linux/tty.h> 29 #include <linux/tty_flip.h> 30 #include <linux/serial_reg.h> 31 #include <linux/delay.h> /* For udelay */ 32 #include <linux/pci.h> 33 #include <linux/slab.h> 34 35 #include "jsm.h" 36 37 static DECLARE_BITMAP(linemap, MAXLINES); 38 39 static void jsm_carrier(struct jsm_channel *ch); 40 41 static inline int jsm_get_mstat(struct jsm_channel *ch) 42 { 43 unsigned char mstat; 44 unsigned result; 45 46 jsm_dbg(IOCTL, &ch->ch_bd->pci_dev, "start\n"); 47 48 mstat = (ch->ch_mostat | ch->ch_mistat); 49 50 result = 0; 51 52 if (mstat & UART_MCR_DTR) 53 result |= TIOCM_DTR; 54 if (mstat & UART_MCR_RTS) 55 result |= TIOCM_RTS; 56 if (mstat & UART_MSR_CTS) 57 result |= TIOCM_CTS; 58 if (mstat & UART_MSR_DSR) 59 result |= TIOCM_DSR; 60 if (mstat & UART_MSR_RI) 61 result |= TIOCM_RI; 62 if (mstat & UART_MSR_DCD) 63 result |= TIOCM_CD; 64 65 jsm_dbg(IOCTL, &ch->ch_bd->pci_dev, "finish\n"); 66 return result; 67 } 68 69 static unsigned int jsm_tty_tx_empty(struct uart_port *port) 70 { 71 return TIOCSER_TEMT; 72 } 73 74 /* 75 * Return modem signals to ld. 76 */ 77 static unsigned int jsm_tty_get_mctrl(struct uart_port *port) 78 { 79 int result; 80 struct jsm_channel *channel = (struct jsm_channel *)port; 81 82 jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "start\n"); 83 84 result = jsm_get_mstat(channel); 85 86 if (result < 0) 87 return -ENXIO; 88 89 jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "finish\n"); 90 91 return result; 92 } 93 94 /* 95 * jsm_set_modem_info() 96 * 97 * Set modem signals, called by ld. 98 */ 99 static void jsm_tty_set_mctrl(struct uart_port *port, unsigned int mctrl) 100 { 101 struct jsm_channel *channel = (struct jsm_channel *)port; 102 103 jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "start\n"); 104 105 if (mctrl & TIOCM_RTS) 106 channel->ch_mostat |= UART_MCR_RTS; 107 else 108 channel->ch_mostat &= ~UART_MCR_RTS; 109 110 if (mctrl & TIOCM_DTR) 111 channel->ch_mostat |= UART_MCR_DTR; 112 else 113 channel->ch_mostat &= ~UART_MCR_DTR; 114 115 channel->ch_bd->bd_ops->assert_modem_signals(channel); 116 117 jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "finish\n"); 118 udelay(10); 119 } 120 121 /* 122 * jsm_tty_write() 123 * 124 * Take data from the user or kernel and send it out to the FEP. 125 * In here exists all the Transparent Print magic as well. 126 */ 127 static void jsm_tty_write(struct uart_port *port) 128 { 129 struct jsm_channel *channel; 130 channel = container_of(port, struct jsm_channel, uart_port); 131 channel->ch_bd->bd_ops->copy_data_from_queue_to_uart(channel); 132 } 133 134 static void jsm_tty_start_tx(struct uart_port *port) 135 { 136 struct jsm_channel *channel = (struct jsm_channel *)port; 137 138 jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "start\n"); 139 140 channel->ch_flags &= ~(CH_STOP); 141 jsm_tty_write(port); 142 143 jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "finish\n"); 144 } 145 146 static void jsm_tty_stop_tx(struct uart_port *port) 147 { 148 struct jsm_channel *channel = (struct jsm_channel *)port; 149 150 jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "start\n"); 151 152 channel->ch_flags |= (CH_STOP); 153 154 jsm_dbg(IOCTL, &channel->ch_bd->pci_dev, "finish\n"); 155 } 156 157 static void jsm_tty_send_xchar(struct uart_port *port, char ch) 158 { 159 unsigned long lock_flags; 160 struct jsm_channel *channel = (struct jsm_channel *)port; 161 struct ktermios *termios; 162 163 spin_lock_irqsave(&port->lock, lock_flags); 164 termios = &port->state->port.tty->termios; 165 if (ch == termios->c_cc[VSTART]) 166 channel->ch_bd->bd_ops->send_start_character(channel); 167 168 if (ch == termios->c_cc[VSTOP]) 169 channel->ch_bd->bd_ops->send_stop_character(channel); 170 spin_unlock_irqrestore(&port->lock, lock_flags); 171 } 172 173 static void jsm_tty_stop_rx(struct uart_port *port) 174 { 175 struct jsm_channel *channel = (struct jsm_channel *)port; 176 177 channel->ch_bd->bd_ops->disable_receiver(channel); 178 } 179 180 static void jsm_tty_break(struct uart_port *port, int break_state) 181 { 182 unsigned long lock_flags; 183 struct jsm_channel *channel = (struct jsm_channel *)port; 184 185 spin_lock_irqsave(&port->lock, lock_flags); 186 if (break_state == -1) 187 channel->ch_bd->bd_ops->send_break(channel); 188 else 189 channel->ch_bd->bd_ops->clear_break(channel, 0); 190 191 spin_unlock_irqrestore(&port->lock, lock_flags); 192 } 193 194 static int jsm_tty_open(struct uart_port *port) 195 { 196 struct jsm_board *brd; 197 struct jsm_channel *channel = (struct jsm_channel *)port; 198 struct ktermios *termios; 199 200 /* Get board pointer from our array of majors we have allocated */ 201 brd = channel->ch_bd; 202 203 /* 204 * Allocate channel buffers for read/write/error. 205 * Set flag, so we don't get trounced on. 206 */ 207 channel->ch_flags |= (CH_OPENING); 208 209 /* Drop locks, as malloc with GFP_KERNEL can sleep */ 210 211 if (!channel->ch_rqueue) { 212 channel->ch_rqueue = kzalloc(RQUEUESIZE, GFP_KERNEL); 213 if (!channel->ch_rqueue) { 214 jsm_dbg(INIT, &channel->ch_bd->pci_dev, 215 "unable to allocate read queue buf\n"); 216 return -ENOMEM; 217 } 218 } 219 if (!channel->ch_equeue) { 220 channel->ch_equeue = kzalloc(EQUEUESIZE, GFP_KERNEL); 221 if (!channel->ch_equeue) { 222 jsm_dbg(INIT, &channel->ch_bd->pci_dev, 223 "unable to allocate error queue buf\n"); 224 return -ENOMEM; 225 } 226 } 227 228 channel->ch_flags &= ~(CH_OPENING); 229 /* 230 * Initialize if neither terminal is open. 231 */ 232 jsm_dbg(OPEN, &channel->ch_bd->pci_dev, 233 "jsm_open: initializing channel in open...\n"); 234 235 /* 236 * Flush input queues. 237 */ 238 channel->ch_r_head = channel->ch_r_tail = 0; 239 channel->ch_e_head = channel->ch_e_tail = 0; 240 241 brd->bd_ops->flush_uart_write(channel); 242 brd->bd_ops->flush_uart_read(channel); 243 244 channel->ch_flags = 0; 245 channel->ch_cached_lsr = 0; 246 channel->ch_stops_sent = 0; 247 248 termios = &port->state->port.tty->termios; 249 channel->ch_c_cflag = termios->c_cflag; 250 channel->ch_c_iflag = termios->c_iflag; 251 channel->ch_c_oflag = termios->c_oflag; 252 channel->ch_c_lflag = termios->c_lflag; 253 channel->ch_startc = termios->c_cc[VSTART]; 254 channel->ch_stopc = termios->c_cc[VSTOP]; 255 256 /* Tell UART to init itself */ 257 brd->bd_ops->uart_init(channel); 258 259 /* 260 * Run param in case we changed anything 261 */ 262 brd->bd_ops->param(channel); 263 264 jsm_carrier(channel); 265 266 channel->ch_open_count++; 267 268 jsm_dbg(OPEN, &channel->ch_bd->pci_dev, "finish\n"); 269 return 0; 270 } 271 272 static void jsm_tty_close(struct uart_port *port) 273 { 274 struct jsm_board *bd; 275 struct ktermios *ts; 276 struct jsm_channel *channel = (struct jsm_channel *)port; 277 278 jsm_dbg(CLOSE, &channel->ch_bd->pci_dev, "start\n"); 279 280 bd = channel->ch_bd; 281 ts = &port->state->port.tty->termios; 282 283 channel->ch_flags &= ~(CH_STOPI); 284 285 channel->ch_open_count--; 286 287 /* 288 * If we have HUPCL set, lower DTR and RTS 289 */ 290 if (channel->ch_c_cflag & HUPCL) { 291 jsm_dbg(CLOSE, &channel->ch_bd->pci_dev, 292 "Close. HUPCL set, dropping DTR/RTS\n"); 293 294 /* Drop RTS/DTR */ 295 channel->ch_mostat &= ~(UART_MCR_DTR | UART_MCR_RTS); 296 bd->bd_ops->assert_modem_signals(channel); 297 } 298 299 /* Turn off UART interrupts for this port */ 300 channel->ch_bd->bd_ops->uart_off(channel); 301 302 jsm_dbg(CLOSE, &channel->ch_bd->pci_dev, "finish\n"); 303 } 304 305 static void jsm_tty_set_termios(struct uart_port *port, 306 struct ktermios *termios, 307 struct ktermios *old_termios) 308 { 309 unsigned long lock_flags; 310 struct jsm_channel *channel = (struct jsm_channel *)port; 311 312 spin_lock_irqsave(&port->lock, lock_flags); 313 channel->ch_c_cflag = termios->c_cflag; 314 channel->ch_c_iflag = termios->c_iflag; 315 channel->ch_c_oflag = termios->c_oflag; 316 channel->ch_c_lflag = termios->c_lflag; 317 channel->ch_startc = termios->c_cc[VSTART]; 318 channel->ch_stopc = termios->c_cc[VSTOP]; 319 320 channel->ch_bd->bd_ops->param(channel); 321 jsm_carrier(channel); 322 spin_unlock_irqrestore(&port->lock, lock_flags); 323 } 324 325 static const char *jsm_tty_type(struct uart_port *port) 326 { 327 return "jsm"; 328 } 329 330 static void jsm_tty_release_port(struct uart_port *port) 331 { 332 } 333 334 static int jsm_tty_request_port(struct uart_port *port) 335 { 336 return 0; 337 } 338 339 static void jsm_config_port(struct uart_port *port, int flags) 340 { 341 port->type = PORT_JSM; 342 } 343 344 static struct uart_ops jsm_ops = { 345 .tx_empty = jsm_tty_tx_empty, 346 .set_mctrl = jsm_tty_set_mctrl, 347 .get_mctrl = jsm_tty_get_mctrl, 348 .stop_tx = jsm_tty_stop_tx, 349 .start_tx = jsm_tty_start_tx, 350 .send_xchar = jsm_tty_send_xchar, 351 .stop_rx = jsm_tty_stop_rx, 352 .break_ctl = jsm_tty_break, 353 .startup = jsm_tty_open, 354 .shutdown = jsm_tty_close, 355 .set_termios = jsm_tty_set_termios, 356 .type = jsm_tty_type, 357 .release_port = jsm_tty_release_port, 358 .request_port = jsm_tty_request_port, 359 .config_port = jsm_config_port, 360 }; 361 362 /* 363 * jsm_tty_init() 364 * 365 * Init the tty subsystem. Called once per board after board has been 366 * downloaded and init'ed. 367 */ 368 int jsm_tty_init(struct jsm_board *brd) 369 { 370 int i; 371 void __iomem *vaddr; 372 struct jsm_channel *ch; 373 374 if (!brd) 375 return -ENXIO; 376 377 jsm_dbg(INIT, &brd->pci_dev, "start\n"); 378 379 /* 380 * Initialize board structure elements. 381 */ 382 383 brd->nasync = brd->maxports; 384 385 /* 386 * Allocate channel memory that might not have been allocated 387 * when the driver was first loaded. 388 */ 389 for (i = 0; i < brd->nasync; i++) { 390 if (!brd->channels[i]) { 391 392 /* 393 * Okay to malloc with GFP_KERNEL, we are not at 394 * interrupt context, and there are no locks held. 395 */ 396 brd->channels[i] = kzalloc(sizeof(struct jsm_channel), GFP_KERNEL); 397 if (!brd->channels[i]) { 398 jsm_dbg(CORE, &brd->pci_dev, 399 "%s:%d Unable to allocate memory for channel struct\n", 400 __FILE__, __LINE__); 401 } 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_dbg(INIT, &brd->pci_dev, "finish\n"); 429 return 0; 430 } 431 432 int jsm_uart_port_init(struct jsm_board *brd) 433 { 434 int i, rc; 435 unsigned int line; 436 struct jsm_channel *ch; 437 438 if (!brd) 439 return -ENXIO; 440 441 jsm_dbg(INIT, &brd->pci_dev, "start\n"); 442 443 /* 444 * Initialize board structure elements. 445 */ 446 447 brd->nasync = brd->maxports; 448 449 /* Set up channel variables */ 450 for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) { 451 452 if (!brd->channels[i]) 453 continue; 454 455 brd->channels[i]->uart_port.irq = brd->irq; 456 brd->channels[i]->uart_port.uartclk = 14745600; 457 brd->channels[i]->uart_port.type = PORT_JSM; 458 brd->channels[i]->uart_port.iotype = UPIO_MEM; 459 brd->channels[i]->uart_port.membase = brd->re_map_membase; 460 brd->channels[i]->uart_port.fifosize = 16; 461 brd->channels[i]->uart_port.ops = &jsm_ops; 462 line = find_first_zero_bit(linemap, MAXLINES); 463 if (line >= MAXLINES) { 464 printk(KERN_INFO "jsm: linemap is full, added device failed\n"); 465 continue; 466 } else 467 set_bit(line, linemap); 468 brd->channels[i]->uart_port.line = line; 469 rc = uart_add_one_port (&jsm_uart_driver, &brd->channels[i]->uart_port); 470 if (rc){ 471 printk(KERN_INFO "jsm: Port %d failed. Aborting...\n", i); 472 return rc; 473 } 474 else 475 printk(KERN_INFO "jsm: Port %d added\n", i); 476 } 477 478 jsm_dbg(INIT, &brd->pci_dev, "finish\n"); 479 return 0; 480 } 481 482 int jsm_remove_uart_port(struct jsm_board *brd) 483 { 484 int i; 485 struct jsm_channel *ch; 486 487 if (!brd) 488 return -ENXIO; 489 490 jsm_dbg(INIT, &brd->pci_dev, "start\n"); 491 492 /* 493 * Initialize board structure elements. 494 */ 495 496 brd->nasync = brd->maxports; 497 498 /* Set up channel variables */ 499 for (i = 0; i < brd->nasync; i++) { 500 501 if (!brd->channels[i]) 502 continue; 503 504 ch = brd->channels[i]; 505 506 clear_bit(ch->uart_port.line, linemap); 507 uart_remove_one_port(&jsm_uart_driver, &brd->channels[i]->uart_port); 508 } 509 510 jsm_dbg(INIT, &brd->pci_dev, "finish\n"); 511 return 0; 512 } 513 514 void jsm_input(struct jsm_channel *ch) 515 { 516 struct jsm_board *bd; 517 struct tty_struct *tp; 518 struct tty_port *port; 519 u32 rmask; 520 u16 head; 521 u16 tail; 522 int data_len; 523 unsigned long lock_flags; 524 int len = 0; 525 int n = 0; 526 int s = 0; 527 int i = 0; 528 529 jsm_dbg(READ, &ch->ch_bd->pci_dev, "start\n"); 530 531 if (!ch) 532 return; 533 534 port = &ch->uart_port.state->port; 535 tp = port->tty; 536 537 bd = ch->ch_bd; 538 if(!bd) 539 return; 540 541 spin_lock_irqsave(&ch->ch_lock, lock_flags); 542 543 /* 544 *Figure the number of characters in the buffer. 545 *Exit immediately if none. 546 */ 547 548 rmask = RQUEUEMASK; 549 550 head = ch->ch_r_head & rmask; 551 tail = ch->ch_r_tail & rmask; 552 553 data_len = (head - tail) & rmask; 554 if (data_len == 0) { 555 spin_unlock_irqrestore(&ch->ch_lock, lock_flags); 556 return; 557 } 558 559 jsm_dbg(READ, &ch->ch_bd->pci_dev, "start\n"); 560 561 /* 562 *If the device is not open, or CREAD is off, flush 563 *input data and return immediately. 564 */ 565 if (!tp || 566 !(tp->termios.c_cflag & CREAD) ) { 567 568 jsm_dbg(READ, &ch->ch_bd->pci_dev, 569 "input. dropping %d bytes on port %d...\n", 570 data_len, ch->ch_portnum); 571 ch->ch_r_head = tail; 572 573 /* Force queue flow control to be released, if needed */ 574 jsm_check_queue_flow_control(ch); 575 576 spin_unlock_irqrestore(&ch->ch_lock, lock_flags); 577 return; 578 } 579 580 /* 581 * If we are throttled, simply don't read any data. 582 */ 583 if (ch->ch_flags & CH_STOPI) { 584 spin_unlock_irqrestore(&ch->ch_lock, lock_flags); 585 jsm_dbg(READ, &ch->ch_bd->pci_dev, 586 "Port %d throttled, not reading any data. head: %x tail: %x\n", 587 ch->ch_portnum, head, tail); 588 return; 589 } 590 591 jsm_dbg(READ, &ch->ch_bd->pci_dev, "start 2\n"); 592 593 len = tty_buffer_request_room(port, data_len); 594 n = len; 595 596 /* 597 * n now contains the most amount of data we can copy, 598 * bounded either by the flip buffer size or the amount 599 * of data the card actually has pending... 600 */ 601 while (n) { 602 s = ((head >= tail) ? head : RQUEUESIZE) - tail; 603 s = min(s, n); 604 605 if (s <= 0) 606 break; 607 608 /* 609 * If conditions are such that ld needs to see all 610 * UART errors, we will have to walk each character 611 * and error byte and send them to the buffer one at 612 * a time. 613 */ 614 615 if (I_PARMRK(tp) || I_BRKINT(tp) || I_INPCK(tp)) { 616 for (i = 0; i < s; i++) { 617 /* 618 * Give the Linux ld the flags in the 619 * format it likes. 620 */ 621 if (*(ch->ch_equeue +tail +i) & UART_LSR_BI) 622 tty_insert_flip_char(port, *(ch->ch_rqueue +tail +i), TTY_BREAK); 623 else if (*(ch->ch_equeue +tail +i) & UART_LSR_PE) 624 tty_insert_flip_char(port, *(ch->ch_rqueue +tail +i), TTY_PARITY); 625 else if (*(ch->ch_equeue +tail +i) & UART_LSR_FE) 626 tty_insert_flip_char(port, *(ch->ch_rqueue +tail +i), TTY_FRAME); 627 else 628 tty_insert_flip_char(port, *(ch->ch_rqueue +tail +i), TTY_NORMAL); 629 } 630 } else { 631 tty_insert_flip_string(port, ch->ch_rqueue + tail, s); 632 } 633 tail += s; 634 n -= s; 635 /* Flip queue if needed */ 636 tail &= rmask; 637 } 638 639 ch->ch_r_tail = tail & rmask; 640 ch->ch_e_tail = tail & rmask; 641 jsm_check_queue_flow_control(ch); 642 spin_unlock_irqrestore(&ch->ch_lock, lock_flags); 643 644 /* Tell the tty layer its okay to "eat" the data now */ 645 tty_flip_buffer_push(port); 646 647 jsm_dbg(IOCTL, &ch->ch_bd->pci_dev, "finish\n"); 648 } 649 650 static void jsm_carrier(struct jsm_channel *ch) 651 { 652 struct jsm_board *bd; 653 654 int virt_carrier = 0; 655 int phys_carrier = 0; 656 657 jsm_dbg(CARR, &ch->ch_bd->pci_dev, "start\n"); 658 if (!ch) 659 return; 660 661 bd = ch->ch_bd; 662 663 if (!bd) 664 return; 665 666 if (ch->ch_mistat & UART_MSR_DCD) { 667 jsm_dbg(CARR, &ch->ch_bd->pci_dev, "mistat: %x D_CD: %x\n", 668 ch->ch_mistat, ch->ch_mistat & UART_MSR_DCD); 669 phys_carrier = 1; 670 } 671 672 if (ch->ch_c_cflag & CLOCAL) 673 virt_carrier = 1; 674 675 jsm_dbg(CARR, &ch->ch_bd->pci_dev, "DCD: physical: %d virt: %d\n", 676 phys_carrier, virt_carrier); 677 678 /* 679 * Test for a VIRTUAL carrier transition to HIGH. 680 */ 681 if (((ch->ch_flags & CH_FCAR) == 0) && (virt_carrier == 1)) { 682 683 /* 684 * When carrier rises, wake any threads waiting 685 * for carrier in the open routine. 686 */ 687 688 jsm_dbg(CARR, &ch->ch_bd->pci_dev, "carrier: virt DCD rose\n"); 689 690 if (waitqueue_active(&(ch->ch_flags_wait))) 691 wake_up_interruptible(&ch->ch_flags_wait); 692 } 693 694 /* 695 * Test for a PHYSICAL carrier transition to HIGH. 696 */ 697 if (((ch->ch_flags & CH_CD) == 0) && (phys_carrier == 1)) { 698 699 /* 700 * When carrier rises, wake any threads waiting 701 * for carrier in the open routine. 702 */ 703 704 jsm_dbg(CARR, &ch->ch_bd->pci_dev, 705 "carrier: physical DCD rose\n"); 706 707 if (waitqueue_active(&(ch->ch_flags_wait))) 708 wake_up_interruptible(&ch->ch_flags_wait); 709 } 710 711 /* 712 * Test for a PHYSICAL transition to low, so long as we aren't 713 * currently ignoring physical transitions (which is what "virtual 714 * carrier" indicates). 715 * 716 * The transition of the virtual carrier to low really doesn't 717 * matter... it really only means "ignore carrier state", not 718 * "make pretend that carrier is there". 719 */ 720 if ((virt_carrier == 0) && ((ch->ch_flags & CH_CD) != 0) 721 && (phys_carrier == 0)) { 722 /* 723 * When carrier drops: 724 * 725 * Drop carrier on all open units. 726 * 727 * Flush queues, waking up any task waiting in the 728 * line discipline. 729 * 730 * Send a hangup to the control terminal. 731 * 732 * Enable all select calls. 733 */ 734 if (waitqueue_active(&(ch->ch_flags_wait))) 735 wake_up_interruptible(&ch->ch_flags_wait); 736 } 737 738 /* 739 * Make sure that our cached values reflect the current reality. 740 */ 741 if (virt_carrier == 1) 742 ch->ch_flags |= CH_FCAR; 743 else 744 ch->ch_flags &= ~CH_FCAR; 745 746 if (phys_carrier == 1) 747 ch->ch_flags |= CH_CD; 748 else 749 ch->ch_flags &= ~CH_CD; 750 } 751 752 753 void jsm_check_queue_flow_control(struct jsm_channel *ch) 754 { 755 struct board_ops *bd_ops = ch->ch_bd->bd_ops; 756 int qleft; 757 758 /* Store how much space we have left in the queue */ 759 if ((qleft = ch->ch_r_tail - ch->ch_r_head - 1) < 0) 760 qleft += RQUEUEMASK + 1; 761 762 /* 763 * Check to see if we should enforce flow control on our queue because 764 * the ld (or user) isn't reading data out of our queue fast enuf. 765 * 766 * NOTE: This is done based on what the current flow control of the 767 * port is set for. 768 * 769 * 1) HWFLOW (RTS) - Turn off the UART's Receive interrupt. 770 * This will cause the UART's FIFO to back up, and force 771 * the RTS signal to be dropped. 772 * 2) SWFLOW (IXOFF) - Keep trying to send a stop character to 773 * the other side, in hopes it will stop sending data to us. 774 * 3) NONE - Nothing we can do. We will simply drop any extra data 775 * that gets sent into us when the queue fills up. 776 */ 777 if (qleft < 256) { 778 /* HWFLOW */ 779 if (ch->ch_c_cflag & CRTSCTS) { 780 if(!(ch->ch_flags & CH_RECEIVER_OFF)) { 781 bd_ops->disable_receiver(ch); 782 ch->ch_flags |= (CH_RECEIVER_OFF); 783 jsm_dbg(READ, &ch->ch_bd->pci_dev, 784 "Internal queue hit hilevel mark (%d)! Turning off interrupts\n", 785 qleft); 786 } 787 } 788 /* SWFLOW */ 789 else if (ch->ch_c_iflag & IXOFF) { 790 if (ch->ch_stops_sent <= MAX_STOPS_SENT) { 791 bd_ops->send_stop_character(ch); 792 ch->ch_stops_sent++; 793 jsm_dbg(READ, &ch->ch_bd->pci_dev, 794 "Sending stop char! Times sent: %x\n", 795 ch->ch_stops_sent); 796 } 797 } 798 } 799 800 /* 801 * Check to see if we should unenforce flow control because 802 * ld (or user) finally read enuf data out of our queue. 803 * 804 * NOTE: This is done based on what the current flow control of the 805 * port is set for. 806 * 807 * 1) HWFLOW (RTS) - Turn back on the UART's Receive interrupt. 808 * This will cause the UART's FIFO to raise RTS back up, 809 * which will allow the other side to start sending data again. 810 * 2) SWFLOW (IXOFF) - Send a start character to 811 * the other side, so it will start sending data to us again. 812 * 3) NONE - Do nothing. Since we didn't do anything to turn off the 813 * other side, we don't need to do anything now. 814 */ 815 if (qleft > (RQUEUESIZE / 2)) { 816 /* HWFLOW */ 817 if (ch->ch_c_cflag & CRTSCTS) { 818 if (ch->ch_flags & CH_RECEIVER_OFF) { 819 bd_ops->enable_receiver(ch); 820 ch->ch_flags &= ~(CH_RECEIVER_OFF); 821 jsm_dbg(READ, &ch->ch_bd->pci_dev, 822 "Internal queue hit lowlevel mark (%d)! Turning on interrupts\n", 823 qleft); 824 } 825 } 826 /* SWFLOW */ 827 else if (ch->ch_c_iflag & IXOFF && ch->ch_stops_sent) { 828 ch->ch_stops_sent = 0; 829 bd_ops->send_start_character(ch); 830 jsm_dbg(READ, &ch->ch_bd->pci_dev, 831 "Sending start char!\n"); 832 } 833 } 834 } 835