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 37static DECLARE_BITMAP(linemap, MAXLINES); 38 39static void jsm_carrier(struct jsm_channel *ch); 40 41static inline int jsm_get_mstat(struct jsm_channel *ch) 42{ 43 unsigned char mstat; 44 unsigned result; 45 46 jsm_printk(IOCTL, INFO, &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_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "finish\n"); 66 return result; 67} 68 69static 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 */ 77static 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_printk(IOCTL, INFO, &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_printk(IOCTL, INFO, &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 */ 99static 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_printk(IOCTL, INFO, &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_printk(IOCTL, INFO, &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 */ 127static 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 134static void jsm_tty_start_tx(struct uart_port *port) 135{ 136 struct jsm_channel *channel = (struct jsm_channel *)port; 137 138 jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n"); 139 140 channel->ch_flags &= ~(CH_STOP); 141 jsm_tty_write(port); 142 143 jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n"); 144} 145 146static void jsm_tty_stop_tx(struct uart_port *port) 147{ 148 struct jsm_channel *channel = (struct jsm_channel *)port; 149 150 jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "start\n"); 151 152 channel->ch_flags |= (CH_STOP); 153 154 jsm_printk(IOCTL, INFO, &channel->ch_bd->pci_dev, "finish\n"); 155} 156 157static 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 173static 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 180static void jsm_tty_enable_ms(struct uart_port *port) 181{ 182 /* Nothing needed */ 183} 184 185static void jsm_tty_break(struct uart_port *port, int break_state) 186{ 187 unsigned long lock_flags; 188 struct jsm_channel *channel = (struct jsm_channel *)port; 189 190 spin_lock_irqsave(&port->lock, lock_flags); 191 if (break_state == -1) 192 channel->ch_bd->bd_ops->send_break(channel); 193 else 194 channel->ch_bd->bd_ops->clear_break(channel, 0); 195 196 spin_unlock_irqrestore(&port->lock, lock_flags); 197} 198 199static int jsm_tty_open(struct uart_port *port) 200{ 201 struct jsm_board *brd; 202 struct jsm_channel *channel = (struct jsm_channel *)port; 203 struct ktermios *termios; 204 205 /* Get board pointer from our array of majors we have allocated */ 206 brd = channel->ch_bd; 207 208 /* 209 * Allocate channel buffers for read/write/error. 210 * Set flag, so we don't get trounced on. 211 */ 212 channel->ch_flags |= (CH_OPENING); 213 214 /* Drop locks, as malloc with GFP_KERNEL can sleep */ 215 216 if (!channel->ch_rqueue) { 217 channel->ch_rqueue = kzalloc(RQUEUESIZE, GFP_KERNEL); 218 if (!channel->ch_rqueue) { 219 jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev, 220 "unable to allocate read queue buf"); 221 return -ENOMEM; 222 } 223 } 224 if (!channel->ch_equeue) { 225 channel->ch_equeue = kzalloc(EQUEUESIZE, GFP_KERNEL); 226 if (!channel->ch_equeue) { 227 jsm_printk(INIT, ERR, &channel->ch_bd->pci_dev, 228 "unable to allocate error queue buf"); 229 return -ENOMEM; 230 } 231 } 232 233 channel->ch_flags &= ~(CH_OPENING); 234 /* 235 * Initialize if neither terminal is open. 236 */ 237 jsm_printk(OPEN, INFO, &channel->ch_bd->pci_dev, 238 "jsm_open: initializing channel in open...\n"); 239 240 /* 241 * Flush input queues. 242 */ 243 channel->ch_r_head = channel->ch_r_tail = 0; 244 channel->ch_e_head = channel->ch_e_tail = 0; 245 246 brd->bd_ops->flush_uart_write(channel); 247 brd->bd_ops->flush_uart_read(channel); 248 249 channel->ch_flags = 0; 250 channel->ch_cached_lsr = 0; 251 channel->ch_stops_sent = 0; 252 253 termios = port->state->port.tty->termios; 254 channel->ch_c_cflag = termios->c_cflag; 255 channel->ch_c_iflag = termios->c_iflag; 256 channel->ch_c_oflag = termios->c_oflag; 257 channel->ch_c_lflag = termios->c_lflag; 258 channel->ch_startc = termios->c_cc[VSTART]; 259 channel->ch_stopc = termios->c_cc[VSTOP]; 260 261 /* Tell UART to init itself */ 262 brd->bd_ops->uart_init(channel); 263 264 /* 265 * Run param in case we changed anything 266 */ 267 brd->bd_ops->param(channel); 268 269 jsm_carrier(channel); 270 271 channel->ch_open_count++; 272 273 jsm_printk(OPEN, INFO, &channel->ch_bd->pci_dev, "finish\n"); 274 return 0; 275} 276 277static void jsm_tty_close(struct uart_port *port) 278{ 279 struct jsm_board *bd; 280 struct ktermios *ts; 281 struct jsm_channel *channel = (struct jsm_channel *)port; 282 283 jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev, "start\n"); 284 285 bd = channel->ch_bd; 286 ts = port->state->port.tty->termios; 287 288 channel->ch_flags &= ~(CH_STOPI); 289 290 channel->ch_open_count--; 291 292 /* 293 * If we have HUPCL set, lower DTR and RTS 294 */ 295 if (channel->ch_c_cflag & HUPCL) { 296 jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev, 297 "Close. HUPCL set, dropping DTR/RTS\n"); 298 299 /* Drop RTS/DTR */ 300 channel->ch_mostat &= ~(UART_MCR_DTR | UART_MCR_RTS); 301 bd->bd_ops->assert_modem_signals(channel); 302 } 303 304 /* Turn off UART interrupts for this port */ 305 channel->ch_bd->bd_ops->uart_off(channel); 306 307 jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev, "finish\n"); 308} 309 310static void jsm_tty_set_termios(struct uart_port *port, 311 struct ktermios *termios, 312 struct ktermios *old_termios) 313{ 314 unsigned long lock_flags; 315 struct jsm_channel *channel = (struct jsm_channel *)port; 316 317 spin_lock_irqsave(&port->lock, lock_flags); 318 channel->ch_c_cflag = termios->c_cflag; 319 channel->ch_c_iflag = termios->c_iflag; 320 channel->ch_c_oflag = termios->c_oflag; 321 channel->ch_c_lflag = termios->c_lflag; 322 channel->ch_startc = termios->c_cc[VSTART]; 323 channel->ch_stopc = termios->c_cc[VSTOP]; 324 325 channel->ch_bd->bd_ops->param(channel); 326 jsm_carrier(channel); 327 spin_unlock_irqrestore(&port->lock, lock_flags); 328} 329 330static const char *jsm_tty_type(struct uart_port *port) 331{ 332 return "jsm"; 333} 334 335static void jsm_tty_release_port(struct uart_port *port) 336{ 337} 338 339static int jsm_tty_request_port(struct uart_port *port) 340{ 341 return 0; 342} 343 344static void jsm_config_port(struct uart_port *port, int flags) 345{ 346 port->type = PORT_JSM; 347} 348 349static struct uart_ops jsm_ops = { 350 .tx_empty = jsm_tty_tx_empty, 351 .set_mctrl = jsm_tty_set_mctrl, 352 .get_mctrl = jsm_tty_get_mctrl, 353 .stop_tx = jsm_tty_stop_tx, 354 .start_tx = jsm_tty_start_tx, 355 .send_xchar = jsm_tty_send_xchar, 356 .stop_rx = jsm_tty_stop_rx, 357 .enable_ms = jsm_tty_enable_ms, 358 .break_ctl = jsm_tty_break, 359 .startup = jsm_tty_open, 360 .shutdown = jsm_tty_close, 361 .set_termios = jsm_tty_set_termios, 362 .type = jsm_tty_type, 363 .release_port = jsm_tty_release_port, 364 .request_port = jsm_tty_request_port, 365 .config_port = jsm_config_port, 366}; 367 368/* 369 * jsm_tty_init() 370 * 371 * Init the tty subsystem. Called once per board after board has been 372 * downloaded and init'ed. 373 */ 374int __devinit jsm_tty_init(struct jsm_board *brd) 375{ 376 int i; 377 void __iomem *vaddr; 378 struct jsm_channel *ch; 379 380 if (!brd) 381 return -ENXIO; 382 383 jsm_printk(INIT, INFO, &brd->pci_dev, "start\n"); 384 385 /* 386 * Initialize board structure elements. 387 */ 388 389 brd->nasync = brd->maxports; 390 391 /* 392 * Allocate channel memory that might not have been allocated 393 * when the driver was first loaded. 394 */ 395 for (i = 0; i < brd->nasync; i++) { 396 if (!brd->channels[i]) { 397 398 /* 399 * Okay to malloc with GFP_KERNEL, we are not at 400 * interrupt context, and there are no locks held. 401 */ 402 brd->channels[i] = kzalloc(sizeof(struct jsm_channel), GFP_KERNEL); 403 if (!brd->channels[i]) { 404 jsm_printk(CORE, ERR, &brd->pci_dev, 405 "%s:%d Unable to allocate memory for channel struct\n", 406 __FILE__, __LINE__); 407 } 408 } 409 } 410 411 ch = brd->channels[0]; 412 vaddr = brd->re_map_membase; 413 414 /* Set up channel variables */ 415 for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) { 416 417 if (!brd->channels[i]) 418 continue; 419 420 spin_lock_init(&ch->ch_lock); 421 422 if (brd->bd_uart_offset == 0x200) 423 ch->ch_neo_uart = vaddr + (brd->bd_uart_offset * i); 424 425 ch->ch_bd = brd; 426 ch->ch_portnum = i; 427 428 /* .25 second delay */ 429 ch->ch_close_delay = 250; 430 431 init_waitqueue_head(&ch->ch_flags_wait); 432 } 433 434 jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n"); 435 return 0; 436} 437 438int jsm_uart_port_init(struct jsm_board *brd) 439{ 440 int i, rc; 441 unsigned int line; 442 struct jsm_channel *ch; 443 444 if (!brd) 445 return -ENXIO; 446 447 jsm_printk(INIT, INFO, &brd->pci_dev, "start\n"); 448 449 /* 450 * Initialize board structure elements. 451 */ 452 453 brd->nasync = brd->maxports; 454 455 /* Set up channel variables */ 456 for (i = 0; i < brd->nasync; i++, ch = brd->channels[i]) { 457 458 if (!brd->channels[i]) 459 continue; 460 461 brd->channels[i]->uart_port.irq = brd->irq; 462 brd->channels[i]->uart_port.uartclk = 14745600; 463 brd->channels[i]->uart_port.type = PORT_JSM; 464 brd->channels[i]->uart_port.iotype = UPIO_MEM; 465 brd->channels[i]->uart_port.membase = brd->re_map_membase; 466 brd->channels[i]->uart_port.fifosize = 16; 467 brd->channels[i]->uart_port.ops = &jsm_ops; 468 line = find_first_zero_bit(linemap, MAXLINES); 469 if (line >= MAXLINES) { 470 printk(KERN_INFO "jsm: linemap is full, added device failed\n"); 471 continue; 472 } else 473 set_bit(line, linemap); 474 brd->channels[i]->uart_port.line = line; 475 rc = uart_add_one_port (&jsm_uart_driver, &brd->channels[i]->uart_port); 476 if (rc){ 477 printk(KERN_INFO "jsm: Port %d failed. Aborting...\n", i); 478 return rc; 479 } 480 else 481 printk(KERN_INFO "jsm: Port %d added\n", i); 482 } 483 484 jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n"); 485 return 0; 486} 487 488int jsm_remove_uart_port(struct jsm_board *brd) 489{ 490 int i; 491 struct jsm_channel *ch; 492 493 if (!brd) 494 return -ENXIO; 495 496 jsm_printk(INIT, INFO, &brd->pci_dev, "start\n"); 497 498 /* 499 * Initialize board structure elements. 500 */ 501 502 brd->nasync = brd->maxports; 503 504 /* Set up channel variables */ 505 for (i = 0; i < brd->nasync; i++) { 506 507 if (!brd->channels[i]) 508 continue; 509 510 ch = brd->channels[i]; 511 512 clear_bit(ch->uart_port.line, linemap); 513 uart_remove_one_port(&jsm_uart_driver, &brd->channels[i]->uart_port); 514 } 515 516 jsm_printk(INIT, INFO, &brd->pci_dev, "finish\n"); 517 return 0; 518} 519 520void jsm_input(struct jsm_channel *ch) 521{ 522 struct jsm_board *bd; 523 struct tty_struct *tp; 524 u32 rmask; 525 u16 head; 526 u16 tail; 527 int data_len; 528 unsigned long lock_flags; 529 int len = 0; 530 int n = 0; 531 int s = 0; 532 int i = 0; 533 534 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n"); 535 536 if (!ch) 537 return; 538 539 tp = ch->uart_port.state->port.tty; 540 541 bd = ch->ch_bd; 542 if(!bd) 543 return; 544 545 spin_lock_irqsave(&ch->ch_lock, lock_flags); 546 547 /* 548 *Figure the number of characters in the buffer. 549 *Exit immediately if none. 550 */ 551 552 rmask = RQUEUEMASK; 553 554 head = ch->ch_r_head & rmask; 555 tail = ch->ch_r_tail & rmask; 556 557 data_len = (head - tail) & rmask; 558 if (data_len == 0) { 559 spin_unlock_irqrestore(&ch->ch_lock, lock_flags); 560 return; 561 } 562 563 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start\n"); 564 565 /* 566 *If the device is not open, or CREAD is off, flush 567 *input data and return immediately. 568 */ 569 if (!tp || 570 !(tp->termios->c_cflag & CREAD) ) { 571 572 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, 573 "input. dropping %d bytes on port %d...\n", data_len, ch->ch_portnum); 574 ch->ch_r_head = tail; 575 576 /* Force queue flow control to be released, if needed */ 577 jsm_check_queue_flow_control(ch); 578 579 spin_unlock_irqrestore(&ch->ch_lock, lock_flags); 580 return; 581 } 582 583 /* 584 * If we are throttled, simply don't read any data. 585 */ 586 if (ch->ch_flags & CH_STOPI) { 587 spin_unlock_irqrestore(&ch->ch_lock, lock_flags); 588 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, 589 "Port %d throttled, not reading any data. head: %x tail: %x\n", 590 ch->ch_portnum, head, tail); 591 return; 592 } 593 594 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "start 2\n"); 595 596 if (data_len <= 0) { 597 spin_unlock_irqrestore(&ch->ch_lock, lock_flags); 598 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "jsm_input 1\n"); 599 return; 600 } 601 602 len = tty_buffer_request_room(tp, data_len); 603 n = len; 604 605 /* 606 * n now contains the most amount of data we can copy, 607 * bounded either by the flip buffer size or the amount 608 * of data the card actually has pending... 609 */ 610 while (n) { 611 s = ((head >= tail) ? head : RQUEUESIZE) - tail; 612 s = min(s, n); 613 614 if (s <= 0) 615 break; 616 617 /* 618 * If conditions are such that ld needs to see all 619 * UART errors, we will have to walk each character 620 * and error byte and send them to the buffer one at 621 * a time. 622 */ 623 624 if (I_PARMRK(tp) || I_BRKINT(tp) || I_INPCK(tp)) { 625 for (i = 0; i < s; i++) { 626 /* 627 * Give the Linux ld the flags in the 628 * format it likes. 629 */ 630 if (*(ch->ch_equeue +tail +i) & UART_LSR_BI) 631 tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_BREAK); 632 else if (*(ch->ch_equeue +tail +i) & UART_LSR_PE) 633 tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_PARITY); 634 else if (*(ch->ch_equeue +tail +i) & UART_LSR_FE) 635 tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_FRAME); 636 else 637 tty_insert_flip_char(tp, *(ch->ch_rqueue +tail +i), TTY_NORMAL); 638 } 639 } else { 640 tty_insert_flip_string(tp, ch->ch_rqueue + tail, s) ; 641 } 642 tail += s; 643 n -= s; 644 /* Flip queue if needed */ 645 tail &= rmask; 646 } 647 648 ch->ch_r_tail = tail & rmask; 649 ch->ch_e_tail = tail & rmask; 650 jsm_check_queue_flow_control(ch); 651 spin_unlock_irqrestore(&ch->ch_lock, lock_flags); 652 653 /* Tell the tty layer its okay to "eat" the data now */ 654 tty_flip_buffer_push(tp); 655 656 jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev, "finish\n"); 657} 658 659static void jsm_carrier(struct jsm_channel *ch) 660{ 661 struct jsm_board *bd; 662 663 int virt_carrier = 0; 664 int phys_carrier = 0; 665 666 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev, "start\n"); 667 if (!ch) 668 return; 669 670 bd = ch->ch_bd; 671 672 if (!bd) 673 return; 674 675 if (ch->ch_mistat & UART_MSR_DCD) { 676 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev, 677 "mistat: %x D_CD: %x\n", ch->ch_mistat, ch->ch_mistat & UART_MSR_DCD); 678 phys_carrier = 1; 679 } 680 681 if (ch->ch_c_cflag & CLOCAL) 682 virt_carrier = 1; 683 684 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev, 685 "DCD: physical: %d virt: %d\n", phys_carrier, virt_carrier); 686 687 /* 688 * Test for a VIRTUAL carrier transition to HIGH. 689 */ 690 if (((ch->ch_flags & CH_FCAR) == 0) && (virt_carrier == 1)) { 691 692 /* 693 * When carrier rises, wake any threads waiting 694 * for carrier in the open routine. 695 */ 696 697 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev, 698 "carrier: virt DCD rose\n"); 699 700 if (waitqueue_active(&(ch->ch_flags_wait))) 701 wake_up_interruptible(&ch->ch_flags_wait); 702 } 703 704 /* 705 * Test for a PHYSICAL carrier transition to HIGH. 706 */ 707 if (((ch->ch_flags & CH_CD) == 0) && (phys_carrier == 1)) { 708 709 /* 710 * When carrier rises, wake any threads waiting 711 * for carrier in the open routine. 712 */ 713 714 jsm_printk(CARR, INFO, &ch->ch_bd->pci_dev, 715 "carrier: physical DCD rose\n"); 716 717 if (waitqueue_active(&(ch->ch_flags_wait))) 718 wake_up_interruptible(&ch->ch_flags_wait); 719 } 720 721 /* 722 * Test for a PHYSICAL transition to low, so long as we aren't 723 * currently ignoring physical transitions (which is what "virtual 724 * carrier" indicates). 725 * 726 * The transition of the virtual carrier to low really doesn't 727 * matter... it really only means "ignore carrier state", not 728 * "make pretend that carrier is there". 729 */ 730 if ((virt_carrier == 0) && ((ch->ch_flags & CH_CD) != 0) 731 && (phys_carrier == 0)) { 732 /* 733 * When carrier drops: 734 * 735 * Drop carrier on all open units. 736 * 737 * Flush queues, waking up any task waiting in the 738 * line discipline. 739 * 740 * Send a hangup to the control terminal. 741 * 742 * Enable all select calls. 743 */ 744 if (waitqueue_active(&(ch->ch_flags_wait))) 745 wake_up_interruptible(&ch->ch_flags_wait); 746 } 747 748 /* 749 * Make sure that our cached values reflect the current reality. 750 */ 751 if (virt_carrier == 1) 752 ch->ch_flags |= CH_FCAR; 753 else 754 ch->ch_flags &= ~CH_FCAR; 755 756 if (phys_carrier == 1) 757 ch->ch_flags |= CH_CD; 758 else 759 ch->ch_flags &= ~CH_CD; 760} 761 762 763void jsm_check_queue_flow_control(struct jsm_channel *ch) 764{ 765 struct board_ops *bd_ops = ch->ch_bd->bd_ops; 766 int qleft; 767 768 /* Store how much space we have left in the queue */ 769 if ((qleft = ch->ch_r_tail - ch->ch_r_head - 1) < 0) 770 qleft += RQUEUEMASK + 1; 771 772 /* 773 * Check to see if we should enforce flow control on our queue because 774 * the ld (or user) isn't reading data out of our queue fast enuf. 775 * 776 * NOTE: This is done based on what the current flow control of the 777 * port is set for. 778 * 779 * 1) HWFLOW (RTS) - Turn off the UART's Receive interrupt. 780 * This will cause the UART's FIFO to back up, and force 781 * the RTS signal to be dropped. 782 * 2) SWFLOW (IXOFF) - Keep trying to send a stop character to 783 * the other side, in hopes it will stop sending data to us. 784 * 3) NONE - Nothing we can do. We will simply drop any extra data 785 * that gets sent into us when the queue fills up. 786 */ 787 if (qleft < 256) { 788 /* HWFLOW */ 789 if (ch->ch_c_cflag & CRTSCTS) { 790 if(!(ch->ch_flags & CH_RECEIVER_OFF)) { 791 bd_ops->disable_receiver(ch); 792 ch->ch_flags |= (CH_RECEIVER_OFF); 793 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, 794 "Internal queue hit hilevel mark (%d)! Turning off interrupts.\n", 795 qleft); 796 } 797 } 798 /* SWFLOW */ 799 else if (ch->ch_c_iflag & IXOFF) { 800 if (ch->ch_stops_sent <= MAX_STOPS_SENT) { 801 bd_ops->send_stop_character(ch); 802 ch->ch_stops_sent++; 803 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, 804 "Sending stop char! Times sent: %x\n", ch->ch_stops_sent); 805 } 806 } 807 } 808 809 /* 810 * Check to see if we should unenforce flow control because 811 * ld (or user) finally read enuf data out of our queue. 812 * 813 * NOTE: This is done based on what the current flow control of the 814 * port is set for. 815 * 816 * 1) HWFLOW (RTS) - Turn back on the UART's Receive interrupt. 817 * This will cause the UART's FIFO to raise RTS back up, 818 * which will allow the other side to start sending data again. 819 * 2) SWFLOW (IXOFF) - Send a start character to 820 * the other side, so it will start sending data to us again. 821 * 3) NONE - Do nothing. Since we didn't do anything to turn off the 822 * other side, we don't need to do anything now. 823 */ 824 if (qleft > (RQUEUESIZE / 2)) { 825 /* HWFLOW */ 826 if (ch->ch_c_cflag & CRTSCTS) { 827 if (ch->ch_flags & CH_RECEIVER_OFF) { 828 bd_ops->enable_receiver(ch); 829 ch->ch_flags &= ~(CH_RECEIVER_OFF); 830 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, 831 "Internal queue hit lowlevel mark (%d)! Turning on interrupts.\n", 832 qleft); 833 } 834 } 835 /* SWFLOW */ 836 else if (ch->ch_c_iflag & IXOFF && ch->ch_stops_sent) { 837 ch->ch_stops_sent = 0; 838 bd_ops->send_start_character(ch); 839 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev, "Sending start char!\n"); 840 } 841 } 842} 843