1 /* 2 * Driver core for serial ports 3 * 4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. 5 * 6 * Copyright 1999 ARM Limited 7 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd. 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License as published by 11 * the Free Software Foundation; either version 2 of the License, or 12 * (at your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, write to the Free Software 21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 22 */ 23 #include <linux/module.h> 24 #include <linux/tty.h> 25 #include <linux/tty_flip.h> 26 #include <linux/slab.h> 27 #include <linux/init.h> 28 #include <linux/console.h> 29 #include <linux/of.h> 30 #include <linux/proc_fs.h> 31 #include <linux/seq_file.h> 32 #include <linux/device.h> 33 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */ 34 #include <linux/serial_core.h> 35 #include <linux/delay.h> 36 #include <linux/mutex.h> 37 38 #include <asm/irq.h> 39 #include <asm/uaccess.h> 40 41 /* 42 * This is used to lock changes in serial line configuration. 43 */ 44 static DEFINE_MUTEX(port_mutex); 45 46 /* 47 * lockdep: port->lock is initialized in two places, but we 48 * want only one lock-class: 49 */ 50 static struct lock_class_key port_lock_key; 51 52 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8) 53 54 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state, 55 struct ktermios *old_termios); 56 static void uart_wait_until_sent(struct tty_struct *tty, int timeout); 57 static void uart_change_pm(struct uart_state *state, 58 enum uart_pm_state pm_state); 59 60 static void uart_port_shutdown(struct tty_port *port); 61 62 static int uart_dcd_enabled(struct uart_port *uport) 63 { 64 return uport->status & UPSTAT_DCD_ENABLE; 65 } 66 67 /* 68 * This routine is used by the interrupt handler to schedule processing in 69 * the software interrupt portion of the driver. 70 */ 71 void uart_write_wakeup(struct uart_port *port) 72 { 73 struct uart_state *state = port->state; 74 /* 75 * This means you called this function _after_ the port was 76 * closed. No cookie for you. 77 */ 78 BUG_ON(!state); 79 tty_wakeup(state->port.tty); 80 } 81 82 static void uart_stop(struct tty_struct *tty) 83 { 84 struct uart_state *state = tty->driver_data; 85 struct uart_port *port = state->uart_port; 86 unsigned long flags; 87 88 spin_lock_irqsave(&port->lock, flags); 89 port->ops->stop_tx(port); 90 spin_unlock_irqrestore(&port->lock, flags); 91 } 92 93 static void __uart_start(struct tty_struct *tty) 94 { 95 struct uart_state *state = tty->driver_data; 96 struct uart_port *port = state->uart_port; 97 98 if (!uart_tx_stopped(port)) 99 port->ops->start_tx(port); 100 } 101 102 static void uart_start(struct tty_struct *tty) 103 { 104 struct uart_state *state = tty->driver_data; 105 struct uart_port *port = state->uart_port; 106 unsigned long flags; 107 108 spin_lock_irqsave(&port->lock, flags); 109 __uart_start(tty); 110 spin_unlock_irqrestore(&port->lock, flags); 111 } 112 113 static inline void 114 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear) 115 { 116 unsigned long flags; 117 unsigned int old; 118 119 spin_lock_irqsave(&port->lock, flags); 120 old = port->mctrl; 121 port->mctrl = (old & ~clear) | set; 122 if (old != port->mctrl) 123 port->ops->set_mctrl(port, port->mctrl); 124 spin_unlock_irqrestore(&port->lock, flags); 125 } 126 127 #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0) 128 #define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear) 129 130 /* 131 * Startup the port. This will be called once per open. All calls 132 * will be serialised by the per-port mutex. 133 */ 134 static int uart_port_startup(struct tty_struct *tty, struct uart_state *state, 135 int init_hw) 136 { 137 struct uart_port *uport = state->uart_port; 138 unsigned long page; 139 int retval = 0; 140 141 if (uport->type == PORT_UNKNOWN) 142 return 1; 143 144 /* 145 * Make sure the device is in D0 state. 146 */ 147 uart_change_pm(state, UART_PM_STATE_ON); 148 149 /* 150 * Initialise and allocate the transmit and temporary 151 * buffer. 152 */ 153 if (!state->xmit.buf) { 154 /* This is protected by the per port mutex */ 155 page = get_zeroed_page(GFP_KERNEL); 156 if (!page) 157 return -ENOMEM; 158 159 state->xmit.buf = (unsigned char *) page; 160 uart_circ_clear(&state->xmit); 161 } 162 163 retval = uport->ops->startup(uport); 164 if (retval == 0) { 165 if (uart_console(uport) && uport->cons->cflag) { 166 tty->termios.c_cflag = uport->cons->cflag; 167 uport->cons->cflag = 0; 168 } 169 /* 170 * Initialise the hardware port settings. 171 */ 172 uart_change_speed(tty, state, NULL); 173 174 if (init_hw) { 175 /* 176 * Setup the RTS and DTR signals once the 177 * port is open and ready to respond. 178 */ 179 if (tty->termios.c_cflag & CBAUD) 180 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR); 181 } 182 183 spin_lock_irq(&uport->lock); 184 if (uart_cts_enabled(uport) && 185 !(uport->ops->get_mctrl(uport) & TIOCM_CTS)) 186 uport->hw_stopped = 1; 187 else 188 uport->hw_stopped = 0; 189 spin_unlock_irq(&uport->lock); 190 } 191 192 /* 193 * This is to allow setserial on this port. People may want to set 194 * port/irq/type and then reconfigure the port properly if it failed 195 * now. 196 */ 197 if (retval && capable(CAP_SYS_ADMIN)) 198 return 1; 199 200 return retval; 201 } 202 203 static int uart_startup(struct tty_struct *tty, struct uart_state *state, 204 int init_hw) 205 { 206 struct tty_port *port = &state->port; 207 int retval; 208 209 if (port->flags & ASYNC_INITIALIZED) 210 return 0; 211 212 /* 213 * Set the TTY IO error marker - we will only clear this 214 * once we have successfully opened the port. 215 */ 216 set_bit(TTY_IO_ERROR, &tty->flags); 217 218 retval = uart_port_startup(tty, state, init_hw); 219 if (!retval) { 220 set_bit(ASYNCB_INITIALIZED, &port->flags); 221 clear_bit(TTY_IO_ERROR, &tty->flags); 222 } else if (retval > 0) 223 retval = 0; 224 225 return retval; 226 } 227 228 /* 229 * This routine will shutdown a serial port; interrupts are disabled, and 230 * DTR is dropped if the hangup on close termio flag is on. Calls to 231 * uart_shutdown are serialised by the per-port semaphore. 232 */ 233 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state) 234 { 235 struct uart_port *uport = state->uart_port; 236 struct tty_port *port = &state->port; 237 238 /* 239 * Set the TTY IO error marker 240 */ 241 if (tty) 242 set_bit(TTY_IO_ERROR, &tty->flags); 243 244 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) { 245 /* 246 * Turn off DTR and RTS early. 247 */ 248 if (uart_console(uport) && tty) 249 uport->cons->cflag = tty->termios.c_cflag; 250 251 if (!tty || (tty->termios.c_cflag & HUPCL)) 252 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS); 253 254 uart_port_shutdown(port); 255 } 256 257 /* 258 * It's possible for shutdown to be called after suspend if we get 259 * a DCD drop (hangup) at just the right time. Clear suspended bit so 260 * we don't try to resume a port that has been shutdown. 261 */ 262 clear_bit(ASYNCB_SUSPENDED, &port->flags); 263 264 /* 265 * Free the transmit buffer page. 266 */ 267 if (state->xmit.buf) { 268 free_page((unsigned long)state->xmit.buf); 269 state->xmit.buf = NULL; 270 } 271 } 272 273 /** 274 * uart_update_timeout - update per-port FIFO timeout. 275 * @port: uart_port structure describing the port 276 * @cflag: termios cflag value 277 * @baud: speed of the port 278 * 279 * Set the port FIFO timeout value. The @cflag value should 280 * reflect the actual hardware settings. 281 */ 282 void 283 uart_update_timeout(struct uart_port *port, unsigned int cflag, 284 unsigned int baud) 285 { 286 unsigned int bits; 287 288 /* byte size and parity */ 289 switch (cflag & CSIZE) { 290 case CS5: 291 bits = 7; 292 break; 293 case CS6: 294 bits = 8; 295 break; 296 case CS7: 297 bits = 9; 298 break; 299 default: 300 bits = 10; 301 break; /* CS8 */ 302 } 303 304 if (cflag & CSTOPB) 305 bits++; 306 if (cflag & PARENB) 307 bits++; 308 309 /* 310 * The total number of bits to be transmitted in the fifo. 311 */ 312 bits = bits * port->fifosize; 313 314 /* 315 * Figure the timeout to send the above number of bits. 316 * Add .02 seconds of slop 317 */ 318 port->timeout = (HZ * bits) / baud + HZ/50; 319 } 320 321 EXPORT_SYMBOL(uart_update_timeout); 322 323 /** 324 * uart_get_baud_rate - return baud rate for a particular port 325 * @port: uart_port structure describing the port in question. 326 * @termios: desired termios settings. 327 * @old: old termios (or NULL) 328 * @min: minimum acceptable baud rate 329 * @max: maximum acceptable baud rate 330 * 331 * Decode the termios structure into a numeric baud rate, 332 * taking account of the magic 38400 baud rate (with spd_* 333 * flags), and mapping the %B0 rate to 9600 baud. 334 * 335 * If the new baud rate is invalid, try the old termios setting. 336 * If it's still invalid, we try 9600 baud. 337 * 338 * Update the @termios structure to reflect the baud rate 339 * we're actually going to be using. Don't do this for the case 340 * where B0 is requested ("hang up"). 341 */ 342 unsigned int 343 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, 344 struct ktermios *old, unsigned int min, unsigned int max) 345 { 346 unsigned int try, baud, altbaud = 38400; 347 int hung_up = 0; 348 upf_t flags = port->flags & UPF_SPD_MASK; 349 350 if (flags == UPF_SPD_HI) 351 altbaud = 57600; 352 else if (flags == UPF_SPD_VHI) 353 altbaud = 115200; 354 else if (flags == UPF_SPD_SHI) 355 altbaud = 230400; 356 else if (flags == UPF_SPD_WARP) 357 altbaud = 460800; 358 359 for (try = 0; try < 2; try++) { 360 baud = tty_termios_baud_rate(termios); 361 362 /* 363 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge... 364 * Die! Die! Die! 365 */ 366 if (try == 0 && baud == 38400) 367 baud = altbaud; 368 369 /* 370 * Special case: B0 rate. 371 */ 372 if (baud == 0) { 373 hung_up = 1; 374 baud = 9600; 375 } 376 377 if (baud >= min && baud <= max) 378 return baud; 379 380 /* 381 * Oops, the quotient was zero. Try again with 382 * the old baud rate if possible. 383 */ 384 termios->c_cflag &= ~CBAUD; 385 if (old) { 386 baud = tty_termios_baud_rate(old); 387 if (!hung_up) 388 tty_termios_encode_baud_rate(termios, 389 baud, baud); 390 old = NULL; 391 continue; 392 } 393 394 /* 395 * As a last resort, if the range cannot be met then clip to 396 * the nearest chip supported rate. 397 */ 398 if (!hung_up) { 399 if (baud <= min) 400 tty_termios_encode_baud_rate(termios, 401 min + 1, min + 1); 402 else 403 tty_termios_encode_baud_rate(termios, 404 max - 1, max - 1); 405 } 406 } 407 /* Should never happen */ 408 WARN_ON(1); 409 return 0; 410 } 411 412 EXPORT_SYMBOL(uart_get_baud_rate); 413 414 /** 415 * uart_get_divisor - return uart clock divisor 416 * @port: uart_port structure describing the port. 417 * @baud: desired baud rate 418 * 419 * Calculate the uart clock divisor for the port. 420 */ 421 unsigned int 422 uart_get_divisor(struct uart_port *port, unsigned int baud) 423 { 424 unsigned int quot; 425 426 /* 427 * Old custom speed handling. 428 */ 429 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST) 430 quot = port->custom_divisor; 431 else 432 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud); 433 434 return quot; 435 } 436 437 EXPORT_SYMBOL(uart_get_divisor); 438 439 /* FIXME: Consistent locking policy */ 440 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state, 441 struct ktermios *old_termios) 442 { 443 struct uart_port *uport = state->uart_port; 444 struct ktermios *termios; 445 446 /* 447 * If we have no tty, termios, or the port does not exist, 448 * then we can't set the parameters for this port. 449 */ 450 if (!tty || uport->type == PORT_UNKNOWN) 451 return; 452 453 termios = &tty->termios; 454 uport->ops->set_termios(uport, termios, old_termios); 455 456 /* 457 * Set modem status enables based on termios cflag 458 */ 459 spin_lock_irq(&uport->lock); 460 if (termios->c_cflag & CRTSCTS) 461 uport->status |= UPSTAT_CTS_ENABLE; 462 else 463 uport->status &= ~UPSTAT_CTS_ENABLE; 464 465 if (termios->c_cflag & CLOCAL) 466 uport->status &= ~UPSTAT_DCD_ENABLE; 467 else 468 uport->status |= UPSTAT_DCD_ENABLE; 469 spin_unlock_irq(&uport->lock); 470 } 471 472 static inline int __uart_put_char(struct uart_port *port, 473 struct circ_buf *circ, unsigned char c) 474 { 475 unsigned long flags; 476 int ret = 0; 477 478 if (!circ->buf) 479 return 0; 480 481 spin_lock_irqsave(&port->lock, flags); 482 if (uart_circ_chars_free(circ) != 0) { 483 circ->buf[circ->head] = c; 484 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1); 485 ret = 1; 486 } 487 spin_unlock_irqrestore(&port->lock, flags); 488 return ret; 489 } 490 491 static int uart_put_char(struct tty_struct *tty, unsigned char ch) 492 { 493 struct uart_state *state = tty->driver_data; 494 495 return __uart_put_char(state->uart_port, &state->xmit, ch); 496 } 497 498 static void uart_flush_chars(struct tty_struct *tty) 499 { 500 uart_start(tty); 501 } 502 503 static int uart_write(struct tty_struct *tty, 504 const unsigned char *buf, int count) 505 { 506 struct uart_state *state = tty->driver_data; 507 struct uart_port *port; 508 struct circ_buf *circ; 509 unsigned long flags; 510 int c, ret = 0; 511 512 /* 513 * This means you called this function _after_ the port was 514 * closed. No cookie for you. 515 */ 516 if (!state) { 517 WARN_ON(1); 518 return -EL3HLT; 519 } 520 521 port = state->uart_port; 522 circ = &state->xmit; 523 524 if (!circ->buf) 525 return 0; 526 527 spin_lock_irqsave(&port->lock, flags); 528 while (1) { 529 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE); 530 if (count < c) 531 c = count; 532 if (c <= 0) 533 break; 534 memcpy(circ->buf + circ->head, buf, c); 535 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1); 536 buf += c; 537 count -= c; 538 ret += c; 539 } 540 spin_unlock_irqrestore(&port->lock, flags); 541 542 uart_start(tty); 543 return ret; 544 } 545 546 static int uart_write_room(struct tty_struct *tty) 547 { 548 struct uart_state *state = tty->driver_data; 549 unsigned long flags; 550 int ret; 551 552 spin_lock_irqsave(&state->uart_port->lock, flags); 553 ret = uart_circ_chars_free(&state->xmit); 554 spin_unlock_irqrestore(&state->uart_port->lock, flags); 555 return ret; 556 } 557 558 static int uart_chars_in_buffer(struct tty_struct *tty) 559 { 560 struct uart_state *state = tty->driver_data; 561 unsigned long flags; 562 int ret; 563 564 spin_lock_irqsave(&state->uart_port->lock, flags); 565 ret = uart_circ_chars_pending(&state->xmit); 566 spin_unlock_irqrestore(&state->uart_port->lock, flags); 567 return ret; 568 } 569 570 static void uart_flush_buffer(struct tty_struct *tty) 571 { 572 struct uart_state *state = tty->driver_data; 573 struct uart_port *port; 574 unsigned long flags; 575 576 /* 577 * This means you called this function _after_ the port was 578 * closed. No cookie for you. 579 */ 580 if (!state) { 581 WARN_ON(1); 582 return; 583 } 584 585 port = state->uart_port; 586 pr_debug("uart_flush_buffer(%d) called\n", tty->index); 587 588 spin_lock_irqsave(&port->lock, flags); 589 uart_circ_clear(&state->xmit); 590 if (port->ops->flush_buffer) 591 port->ops->flush_buffer(port); 592 spin_unlock_irqrestore(&port->lock, flags); 593 tty_wakeup(tty); 594 } 595 596 /* 597 * This function is used to send a high-priority XON/XOFF character to 598 * the device 599 */ 600 static void uart_send_xchar(struct tty_struct *tty, char ch) 601 { 602 struct uart_state *state = tty->driver_data; 603 struct uart_port *port = state->uart_port; 604 unsigned long flags; 605 606 if (port->ops->send_xchar) 607 port->ops->send_xchar(port, ch); 608 else { 609 spin_lock_irqsave(&port->lock, flags); 610 port->x_char = ch; 611 if (ch) 612 port->ops->start_tx(port); 613 spin_unlock_irqrestore(&port->lock, flags); 614 } 615 } 616 617 static void uart_throttle(struct tty_struct *tty) 618 { 619 struct uart_state *state = tty->driver_data; 620 struct uart_port *port = state->uart_port; 621 uint32_t mask = 0; 622 623 if (I_IXOFF(tty)) 624 mask |= UPF_SOFT_FLOW; 625 if (tty->termios.c_cflag & CRTSCTS) 626 mask |= UPF_HARD_FLOW; 627 628 if (port->flags & mask) { 629 port->ops->throttle(port); 630 mask &= ~port->flags; 631 } 632 633 if (mask & UPF_SOFT_FLOW) 634 uart_send_xchar(tty, STOP_CHAR(tty)); 635 636 if (mask & UPF_HARD_FLOW) 637 uart_clear_mctrl(port, TIOCM_RTS); 638 } 639 640 static void uart_unthrottle(struct tty_struct *tty) 641 { 642 struct uart_state *state = tty->driver_data; 643 struct uart_port *port = state->uart_port; 644 uint32_t mask = 0; 645 646 if (I_IXOFF(tty)) 647 mask |= UPF_SOFT_FLOW; 648 if (tty->termios.c_cflag & CRTSCTS) 649 mask |= UPF_HARD_FLOW; 650 651 if (port->flags & mask) { 652 port->ops->unthrottle(port); 653 mask &= ~port->flags; 654 } 655 656 if (mask & UPF_SOFT_FLOW) 657 uart_send_xchar(tty, START_CHAR(tty)); 658 659 if (mask & UPF_HARD_FLOW) 660 uart_set_mctrl(port, TIOCM_RTS); 661 } 662 663 static void do_uart_get_info(struct tty_port *port, 664 struct serial_struct *retinfo) 665 { 666 struct uart_state *state = container_of(port, struct uart_state, port); 667 struct uart_port *uport = state->uart_port; 668 669 memset(retinfo, 0, sizeof(*retinfo)); 670 671 retinfo->type = uport->type; 672 retinfo->line = uport->line; 673 retinfo->port = uport->iobase; 674 if (HIGH_BITS_OFFSET) 675 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET; 676 retinfo->irq = uport->irq; 677 retinfo->flags = uport->flags; 678 retinfo->xmit_fifo_size = uport->fifosize; 679 retinfo->baud_base = uport->uartclk / 16; 680 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10; 681 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ? 682 ASYNC_CLOSING_WAIT_NONE : 683 jiffies_to_msecs(port->closing_wait) / 10; 684 retinfo->custom_divisor = uport->custom_divisor; 685 retinfo->hub6 = uport->hub6; 686 retinfo->io_type = uport->iotype; 687 retinfo->iomem_reg_shift = uport->regshift; 688 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase; 689 } 690 691 static void uart_get_info(struct tty_port *port, 692 struct serial_struct *retinfo) 693 { 694 /* Ensure the state we copy is consistent and no hardware changes 695 occur as we go */ 696 mutex_lock(&port->mutex); 697 do_uart_get_info(port, retinfo); 698 mutex_unlock(&port->mutex); 699 } 700 701 static int uart_get_info_user(struct tty_port *port, 702 struct serial_struct __user *retinfo) 703 { 704 struct serial_struct tmp; 705 uart_get_info(port, &tmp); 706 707 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo))) 708 return -EFAULT; 709 return 0; 710 } 711 712 static int uart_set_info(struct tty_struct *tty, struct tty_port *port, 713 struct uart_state *state, 714 struct serial_struct *new_info) 715 { 716 struct uart_port *uport = state->uart_port; 717 unsigned long new_port; 718 unsigned int change_irq, change_port, closing_wait; 719 unsigned int old_custom_divisor, close_delay; 720 upf_t old_flags, new_flags; 721 int retval = 0; 722 723 new_port = new_info->port; 724 if (HIGH_BITS_OFFSET) 725 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET; 726 727 new_info->irq = irq_canonicalize(new_info->irq); 728 close_delay = msecs_to_jiffies(new_info->close_delay * 10); 729 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ? 730 ASYNC_CLOSING_WAIT_NONE : 731 msecs_to_jiffies(new_info->closing_wait * 10); 732 733 734 change_irq = !(uport->flags & UPF_FIXED_PORT) 735 && new_info->irq != uport->irq; 736 737 /* 738 * Since changing the 'type' of the port changes its resource 739 * allocations, we should treat type changes the same as 740 * IO port changes. 741 */ 742 change_port = !(uport->flags & UPF_FIXED_PORT) 743 && (new_port != uport->iobase || 744 (unsigned long)new_info->iomem_base != uport->mapbase || 745 new_info->hub6 != uport->hub6 || 746 new_info->io_type != uport->iotype || 747 new_info->iomem_reg_shift != uport->regshift || 748 new_info->type != uport->type); 749 750 old_flags = uport->flags; 751 new_flags = new_info->flags; 752 old_custom_divisor = uport->custom_divisor; 753 754 if (!capable(CAP_SYS_ADMIN)) { 755 retval = -EPERM; 756 if (change_irq || change_port || 757 (new_info->baud_base != uport->uartclk / 16) || 758 (close_delay != port->close_delay) || 759 (closing_wait != port->closing_wait) || 760 (new_info->xmit_fifo_size && 761 new_info->xmit_fifo_size != uport->fifosize) || 762 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0)) 763 goto exit; 764 uport->flags = ((uport->flags & ~UPF_USR_MASK) | 765 (new_flags & UPF_USR_MASK)); 766 uport->custom_divisor = new_info->custom_divisor; 767 goto check_and_exit; 768 } 769 770 /* 771 * Ask the low level driver to verify the settings. 772 */ 773 if (uport->ops->verify_port) 774 retval = uport->ops->verify_port(uport, new_info); 775 776 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) || 777 (new_info->baud_base < 9600)) 778 retval = -EINVAL; 779 780 if (retval) 781 goto exit; 782 783 if (change_port || change_irq) { 784 retval = -EBUSY; 785 786 /* 787 * Make sure that we are the sole user of this port. 788 */ 789 if (tty_port_users(port) > 1) 790 goto exit; 791 792 /* 793 * We need to shutdown the serial port at the old 794 * port/type/irq combination. 795 */ 796 uart_shutdown(tty, state); 797 } 798 799 if (change_port) { 800 unsigned long old_iobase, old_mapbase; 801 unsigned int old_type, old_iotype, old_hub6, old_shift; 802 803 old_iobase = uport->iobase; 804 old_mapbase = uport->mapbase; 805 old_type = uport->type; 806 old_hub6 = uport->hub6; 807 old_iotype = uport->iotype; 808 old_shift = uport->regshift; 809 810 /* 811 * Free and release old regions 812 */ 813 if (old_type != PORT_UNKNOWN) 814 uport->ops->release_port(uport); 815 816 uport->iobase = new_port; 817 uport->type = new_info->type; 818 uport->hub6 = new_info->hub6; 819 uport->iotype = new_info->io_type; 820 uport->regshift = new_info->iomem_reg_shift; 821 uport->mapbase = (unsigned long)new_info->iomem_base; 822 823 /* 824 * Claim and map the new regions 825 */ 826 if (uport->type != PORT_UNKNOWN) { 827 retval = uport->ops->request_port(uport); 828 } else { 829 /* Always success - Jean II */ 830 retval = 0; 831 } 832 833 /* 834 * If we fail to request resources for the 835 * new port, try to restore the old settings. 836 */ 837 if (retval) { 838 uport->iobase = old_iobase; 839 uport->type = old_type; 840 uport->hub6 = old_hub6; 841 uport->iotype = old_iotype; 842 uport->regshift = old_shift; 843 uport->mapbase = old_mapbase; 844 845 if (old_type != PORT_UNKNOWN) { 846 retval = uport->ops->request_port(uport); 847 /* 848 * If we failed to restore the old settings, 849 * we fail like this. 850 */ 851 if (retval) 852 uport->type = PORT_UNKNOWN; 853 854 /* 855 * We failed anyway. 856 */ 857 retval = -EBUSY; 858 } 859 860 /* Added to return the correct error -Ram Gupta */ 861 goto exit; 862 } 863 } 864 865 if (change_irq) 866 uport->irq = new_info->irq; 867 if (!(uport->flags & UPF_FIXED_PORT)) 868 uport->uartclk = new_info->baud_base * 16; 869 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) | 870 (new_flags & UPF_CHANGE_MASK); 871 uport->custom_divisor = new_info->custom_divisor; 872 port->close_delay = close_delay; 873 port->closing_wait = closing_wait; 874 if (new_info->xmit_fifo_size) 875 uport->fifosize = new_info->xmit_fifo_size; 876 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0; 877 878 check_and_exit: 879 retval = 0; 880 if (uport->type == PORT_UNKNOWN) 881 goto exit; 882 if (port->flags & ASYNC_INITIALIZED) { 883 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) || 884 old_custom_divisor != uport->custom_divisor) { 885 /* 886 * If they're setting up a custom divisor or speed, 887 * instead of clearing it, then bitch about it. No 888 * need to rate-limit; it's CAP_SYS_ADMIN only. 889 */ 890 if (uport->flags & UPF_SPD_MASK) { 891 char buf[64]; 892 893 dev_notice(uport->dev, 894 "%s sets custom speed on %s. This is deprecated.\n", 895 current->comm, 896 tty_name(port->tty, buf)); 897 } 898 uart_change_speed(tty, state, NULL); 899 } 900 } else 901 retval = uart_startup(tty, state, 1); 902 exit: 903 return retval; 904 } 905 906 static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state, 907 struct serial_struct __user *newinfo) 908 { 909 struct serial_struct new_serial; 910 struct tty_port *port = &state->port; 911 int retval; 912 913 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial))) 914 return -EFAULT; 915 916 /* 917 * This semaphore protects port->count. It is also 918 * very useful to prevent opens. Also, take the 919 * port configuration semaphore to make sure that a 920 * module insertion/removal doesn't change anything 921 * under us. 922 */ 923 mutex_lock(&port->mutex); 924 retval = uart_set_info(tty, port, state, &new_serial); 925 mutex_unlock(&port->mutex); 926 return retval; 927 } 928 929 /** 930 * uart_get_lsr_info - get line status register info 931 * @tty: tty associated with the UART 932 * @state: UART being queried 933 * @value: returned modem value 934 * 935 * Note: uart_ioctl protects us against hangups. 936 */ 937 static int uart_get_lsr_info(struct tty_struct *tty, 938 struct uart_state *state, unsigned int __user *value) 939 { 940 struct uart_port *uport = state->uart_port; 941 unsigned int result; 942 943 result = uport->ops->tx_empty(uport); 944 945 /* 946 * If we're about to load something into the transmit 947 * register, we'll pretend the transmitter isn't empty to 948 * avoid a race condition (depending on when the transmit 949 * interrupt happens). 950 */ 951 if (uport->x_char || 952 ((uart_circ_chars_pending(&state->xmit) > 0) && 953 !uart_tx_stopped(uport))) 954 result &= ~TIOCSER_TEMT; 955 956 return put_user(result, value); 957 } 958 959 static int uart_tiocmget(struct tty_struct *tty) 960 { 961 struct uart_state *state = tty->driver_data; 962 struct tty_port *port = &state->port; 963 struct uart_port *uport = state->uart_port; 964 int result = -EIO; 965 966 mutex_lock(&port->mutex); 967 if (!(tty->flags & (1 << TTY_IO_ERROR))) { 968 result = uport->mctrl; 969 spin_lock_irq(&uport->lock); 970 result |= uport->ops->get_mctrl(uport); 971 spin_unlock_irq(&uport->lock); 972 } 973 mutex_unlock(&port->mutex); 974 975 return result; 976 } 977 978 static int 979 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear) 980 { 981 struct uart_state *state = tty->driver_data; 982 struct uart_port *uport = state->uart_port; 983 struct tty_port *port = &state->port; 984 int ret = -EIO; 985 986 mutex_lock(&port->mutex); 987 if (!(tty->flags & (1 << TTY_IO_ERROR))) { 988 uart_update_mctrl(uport, set, clear); 989 ret = 0; 990 } 991 mutex_unlock(&port->mutex); 992 return ret; 993 } 994 995 static int uart_break_ctl(struct tty_struct *tty, int break_state) 996 { 997 struct uart_state *state = tty->driver_data; 998 struct tty_port *port = &state->port; 999 struct uart_port *uport = state->uart_port; 1000 1001 mutex_lock(&port->mutex); 1002 1003 if (uport->type != PORT_UNKNOWN) 1004 uport->ops->break_ctl(uport, break_state); 1005 1006 mutex_unlock(&port->mutex); 1007 return 0; 1008 } 1009 1010 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state) 1011 { 1012 struct uart_port *uport = state->uart_port; 1013 struct tty_port *port = &state->port; 1014 int flags, ret; 1015 1016 if (!capable(CAP_SYS_ADMIN)) 1017 return -EPERM; 1018 1019 /* 1020 * Take the per-port semaphore. This prevents count from 1021 * changing, and hence any extra opens of the port while 1022 * we're auto-configuring. 1023 */ 1024 if (mutex_lock_interruptible(&port->mutex)) 1025 return -ERESTARTSYS; 1026 1027 ret = -EBUSY; 1028 if (tty_port_users(port) == 1) { 1029 uart_shutdown(tty, state); 1030 1031 /* 1032 * If we already have a port type configured, 1033 * we must release its resources. 1034 */ 1035 if (uport->type != PORT_UNKNOWN) 1036 uport->ops->release_port(uport); 1037 1038 flags = UART_CONFIG_TYPE; 1039 if (uport->flags & UPF_AUTO_IRQ) 1040 flags |= UART_CONFIG_IRQ; 1041 1042 /* 1043 * This will claim the ports resources if 1044 * a port is found. 1045 */ 1046 uport->ops->config_port(uport, flags); 1047 1048 ret = uart_startup(tty, state, 1); 1049 } 1050 mutex_unlock(&port->mutex); 1051 return ret; 1052 } 1053 1054 static void uart_enable_ms(struct uart_port *uport) 1055 { 1056 /* 1057 * Force modem status interrupts on 1058 */ 1059 if (uport->ops->enable_ms) 1060 uport->ops->enable_ms(uport); 1061 } 1062 1063 /* 1064 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change 1065 * - mask passed in arg for lines of interest 1066 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking) 1067 * Caller should use TIOCGICOUNT to see which one it was 1068 * 1069 * FIXME: This wants extracting into a common all driver implementation 1070 * of TIOCMWAIT using tty_port. 1071 */ 1072 static int 1073 uart_wait_modem_status(struct uart_state *state, unsigned long arg) 1074 { 1075 struct uart_port *uport = state->uart_port; 1076 struct tty_port *port = &state->port; 1077 DECLARE_WAITQUEUE(wait, current); 1078 struct uart_icount cprev, cnow; 1079 int ret; 1080 1081 /* 1082 * note the counters on entry 1083 */ 1084 spin_lock_irq(&uport->lock); 1085 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount)); 1086 uart_enable_ms(uport); 1087 spin_unlock_irq(&uport->lock); 1088 1089 add_wait_queue(&port->delta_msr_wait, &wait); 1090 for (;;) { 1091 spin_lock_irq(&uport->lock); 1092 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount)); 1093 spin_unlock_irq(&uport->lock); 1094 1095 set_current_state(TASK_INTERRUPTIBLE); 1096 1097 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) || 1098 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) || 1099 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) || 1100 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) { 1101 ret = 0; 1102 break; 1103 } 1104 1105 schedule(); 1106 1107 /* see if a signal did it */ 1108 if (signal_pending(current)) { 1109 ret = -ERESTARTSYS; 1110 break; 1111 } 1112 1113 cprev = cnow; 1114 } 1115 1116 current->state = TASK_RUNNING; 1117 remove_wait_queue(&port->delta_msr_wait, &wait); 1118 1119 return ret; 1120 } 1121 1122 /* 1123 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS) 1124 * Return: write counters to the user passed counter struct 1125 * NB: both 1->0 and 0->1 transitions are counted except for 1126 * RI where only 0->1 is counted. 1127 */ 1128 static int uart_get_icount(struct tty_struct *tty, 1129 struct serial_icounter_struct *icount) 1130 { 1131 struct uart_state *state = tty->driver_data; 1132 struct uart_icount cnow; 1133 struct uart_port *uport = state->uart_port; 1134 1135 spin_lock_irq(&uport->lock); 1136 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount)); 1137 spin_unlock_irq(&uport->lock); 1138 1139 icount->cts = cnow.cts; 1140 icount->dsr = cnow.dsr; 1141 icount->rng = cnow.rng; 1142 icount->dcd = cnow.dcd; 1143 icount->rx = cnow.rx; 1144 icount->tx = cnow.tx; 1145 icount->frame = cnow.frame; 1146 icount->overrun = cnow.overrun; 1147 icount->parity = cnow.parity; 1148 icount->brk = cnow.brk; 1149 icount->buf_overrun = cnow.buf_overrun; 1150 1151 return 0; 1152 } 1153 1154 /* 1155 * Called via sys_ioctl. We can use spin_lock_irq() here. 1156 */ 1157 static int 1158 uart_ioctl(struct tty_struct *tty, unsigned int cmd, 1159 unsigned long arg) 1160 { 1161 struct uart_state *state = tty->driver_data; 1162 struct tty_port *port = &state->port; 1163 void __user *uarg = (void __user *)arg; 1164 int ret = -ENOIOCTLCMD; 1165 1166 1167 /* 1168 * These ioctls don't rely on the hardware to be present. 1169 */ 1170 switch (cmd) { 1171 case TIOCGSERIAL: 1172 ret = uart_get_info_user(port, uarg); 1173 break; 1174 1175 case TIOCSSERIAL: 1176 ret = uart_set_info_user(tty, state, uarg); 1177 break; 1178 1179 case TIOCSERCONFIG: 1180 ret = uart_do_autoconfig(tty, state); 1181 break; 1182 1183 case TIOCSERGWILD: /* obsolete */ 1184 case TIOCSERSWILD: /* obsolete */ 1185 ret = 0; 1186 break; 1187 } 1188 1189 if (ret != -ENOIOCTLCMD) 1190 goto out; 1191 1192 if (tty->flags & (1 << TTY_IO_ERROR)) { 1193 ret = -EIO; 1194 goto out; 1195 } 1196 1197 /* 1198 * The following should only be used when hardware is present. 1199 */ 1200 switch (cmd) { 1201 case TIOCMIWAIT: 1202 ret = uart_wait_modem_status(state, arg); 1203 break; 1204 } 1205 1206 if (ret != -ENOIOCTLCMD) 1207 goto out; 1208 1209 mutex_lock(&port->mutex); 1210 1211 if (tty->flags & (1 << TTY_IO_ERROR)) { 1212 ret = -EIO; 1213 goto out_up; 1214 } 1215 1216 /* 1217 * All these rely on hardware being present and need to be 1218 * protected against the tty being hung up. 1219 */ 1220 switch (cmd) { 1221 case TIOCSERGETLSR: /* Get line status register */ 1222 ret = uart_get_lsr_info(tty, state, uarg); 1223 break; 1224 1225 default: { 1226 struct uart_port *uport = state->uart_port; 1227 if (uport->ops->ioctl) 1228 ret = uport->ops->ioctl(uport, cmd, arg); 1229 break; 1230 } 1231 } 1232 out_up: 1233 mutex_unlock(&port->mutex); 1234 out: 1235 return ret; 1236 } 1237 1238 static void uart_set_ldisc(struct tty_struct *tty) 1239 { 1240 struct uart_state *state = tty->driver_data; 1241 struct uart_port *uport = state->uart_port; 1242 1243 if (uport->ops->set_ldisc) 1244 uport->ops->set_ldisc(uport, tty->termios.c_line); 1245 } 1246 1247 static void uart_set_termios(struct tty_struct *tty, 1248 struct ktermios *old_termios) 1249 { 1250 struct uart_state *state = tty->driver_data; 1251 struct uart_port *uport = state->uart_port; 1252 unsigned int cflag = tty->termios.c_cflag; 1253 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK; 1254 bool sw_changed = false; 1255 1256 /* 1257 * Drivers doing software flow control also need to know 1258 * about changes to these input settings. 1259 */ 1260 if (uport->flags & UPF_SOFT_FLOW) { 1261 iflag_mask |= IXANY|IXON|IXOFF; 1262 sw_changed = 1263 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] || 1264 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP]; 1265 } 1266 1267 /* 1268 * These are the bits that are used to setup various 1269 * flags in the low level driver. We can ignore the Bfoo 1270 * bits in c_cflag; c_[io]speed will always be set 1271 * appropriately by set_termios() in tty_ioctl.c 1272 */ 1273 if ((cflag ^ old_termios->c_cflag) == 0 && 1274 tty->termios.c_ospeed == old_termios->c_ospeed && 1275 tty->termios.c_ispeed == old_termios->c_ispeed && 1276 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 && 1277 !sw_changed) { 1278 return; 1279 } 1280 1281 uart_change_speed(tty, state, old_termios); 1282 /* reload cflag from termios; port driver may have overriden flags */ 1283 cflag = tty->termios.c_cflag; 1284 1285 /* Handle transition to B0 status */ 1286 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD)) 1287 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR); 1288 /* Handle transition away from B0 status */ 1289 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) { 1290 unsigned int mask = TIOCM_DTR; 1291 if (!(cflag & CRTSCTS) || !test_bit(TTY_THROTTLED, &tty->flags)) 1292 mask |= TIOCM_RTS; 1293 uart_set_mctrl(uport, mask); 1294 } 1295 1296 /* 1297 * If the port is doing h/w assisted flow control, do nothing. 1298 * We assume that port->hw_stopped has never been set. 1299 */ 1300 if (uport->flags & UPF_HARD_FLOW) 1301 return; 1302 1303 /* Handle turning off CRTSCTS */ 1304 if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) { 1305 spin_lock_irq(&uport->lock); 1306 uport->hw_stopped = 0; 1307 __uart_start(tty); 1308 spin_unlock_irq(&uport->lock); 1309 } 1310 /* Handle turning on CRTSCTS */ 1311 else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) { 1312 spin_lock_irq(&uport->lock); 1313 if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS)) { 1314 uport->hw_stopped = 1; 1315 uport->ops->stop_tx(uport); 1316 } 1317 spin_unlock_irq(&uport->lock); 1318 } 1319 } 1320 1321 /* 1322 * Calls to uart_close() are serialised via the tty_lock in 1323 * drivers/tty/tty_io.c:tty_release() 1324 * drivers/tty/tty_io.c:do_tty_hangup() 1325 * This runs from a workqueue and can sleep for a _short_ time only. 1326 */ 1327 static void uart_close(struct tty_struct *tty, struct file *filp) 1328 { 1329 struct uart_state *state = tty->driver_data; 1330 struct tty_port *port; 1331 struct uart_port *uport; 1332 unsigned long flags; 1333 1334 if (!state) 1335 return; 1336 1337 uport = state->uart_port; 1338 port = &state->port; 1339 1340 pr_debug("uart_close(%d) called\n", uport ? uport->line : -1); 1341 1342 if (!port->count || tty_port_close_start(port, tty, filp) == 0) 1343 return; 1344 1345 /* 1346 * At this point, we stop accepting input. To do this, we 1347 * disable the receive line status interrupts. 1348 */ 1349 if (port->flags & ASYNC_INITIALIZED) { 1350 unsigned long flags; 1351 spin_lock_irqsave(&uport->lock, flags); 1352 uport->ops->stop_rx(uport); 1353 spin_unlock_irqrestore(&uport->lock, flags); 1354 /* 1355 * Before we drop DTR, make sure the UART transmitter 1356 * has completely drained; this is especially 1357 * important if there is a transmit FIFO! 1358 */ 1359 uart_wait_until_sent(tty, uport->timeout); 1360 } 1361 1362 mutex_lock(&port->mutex); 1363 uart_shutdown(tty, state); 1364 uart_flush_buffer(tty); 1365 1366 tty_ldisc_flush(tty); 1367 1368 tty_port_tty_set(port, NULL); 1369 tty->closing = 0; 1370 spin_lock_irqsave(&port->lock, flags); 1371 1372 if (port->blocked_open) { 1373 spin_unlock_irqrestore(&port->lock, flags); 1374 if (port->close_delay) 1375 msleep_interruptible( 1376 jiffies_to_msecs(port->close_delay)); 1377 spin_lock_irqsave(&port->lock, flags); 1378 } else if (!uart_console(uport)) { 1379 spin_unlock_irqrestore(&port->lock, flags); 1380 uart_change_pm(state, UART_PM_STATE_OFF); 1381 spin_lock_irqsave(&port->lock, flags); 1382 } 1383 1384 /* 1385 * Wake up anyone trying to open this port. 1386 */ 1387 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags); 1388 clear_bit(ASYNCB_CLOSING, &port->flags); 1389 spin_unlock_irqrestore(&port->lock, flags); 1390 wake_up_interruptible(&port->open_wait); 1391 wake_up_interruptible(&port->close_wait); 1392 1393 mutex_unlock(&port->mutex); 1394 } 1395 1396 static void uart_wait_until_sent(struct tty_struct *tty, int timeout) 1397 { 1398 struct uart_state *state = tty->driver_data; 1399 struct uart_port *port = state->uart_port; 1400 unsigned long char_time, expire; 1401 1402 if (port->type == PORT_UNKNOWN || port->fifosize == 0) 1403 return; 1404 1405 /* 1406 * Set the check interval to be 1/5 of the estimated time to 1407 * send a single character, and make it at least 1. The check 1408 * interval should also be less than the timeout. 1409 * 1410 * Note: we have to use pretty tight timings here to satisfy 1411 * the NIST-PCTS. 1412 */ 1413 char_time = (port->timeout - HZ/50) / port->fifosize; 1414 char_time = char_time / 5; 1415 if (char_time == 0) 1416 char_time = 1; 1417 if (timeout && timeout < char_time) 1418 char_time = timeout; 1419 1420 /* 1421 * If the transmitter hasn't cleared in twice the approximate 1422 * amount of time to send the entire FIFO, it probably won't 1423 * ever clear. This assumes the UART isn't doing flow 1424 * control, which is currently the case. Hence, if it ever 1425 * takes longer than port->timeout, this is probably due to a 1426 * UART bug of some kind. So, we clamp the timeout parameter at 1427 * 2*port->timeout. 1428 */ 1429 if (timeout == 0 || timeout > 2 * port->timeout) 1430 timeout = 2 * port->timeout; 1431 1432 expire = jiffies + timeout; 1433 1434 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n", 1435 port->line, jiffies, expire); 1436 1437 /* 1438 * Check whether the transmitter is empty every 'char_time'. 1439 * 'timeout' / 'expire' give us the maximum amount of time 1440 * we wait. 1441 */ 1442 while (!port->ops->tx_empty(port)) { 1443 msleep_interruptible(jiffies_to_msecs(char_time)); 1444 if (signal_pending(current)) 1445 break; 1446 if (time_after(jiffies, expire)) 1447 break; 1448 } 1449 } 1450 1451 /* 1452 * Calls to uart_hangup() are serialised by the tty_lock in 1453 * drivers/tty/tty_io.c:do_tty_hangup() 1454 * This runs from a workqueue and can sleep for a _short_ time only. 1455 */ 1456 static void uart_hangup(struct tty_struct *tty) 1457 { 1458 struct uart_state *state = tty->driver_data; 1459 struct tty_port *port = &state->port; 1460 unsigned long flags; 1461 1462 pr_debug("uart_hangup(%d)\n", state->uart_port->line); 1463 1464 mutex_lock(&port->mutex); 1465 if (port->flags & ASYNC_NORMAL_ACTIVE) { 1466 uart_flush_buffer(tty); 1467 uart_shutdown(tty, state); 1468 spin_lock_irqsave(&port->lock, flags); 1469 port->count = 0; 1470 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags); 1471 spin_unlock_irqrestore(&port->lock, flags); 1472 tty_port_tty_set(port, NULL); 1473 if (!uart_console(state->uart_port)) 1474 uart_change_pm(state, UART_PM_STATE_OFF); 1475 wake_up_interruptible(&port->open_wait); 1476 wake_up_interruptible(&port->delta_msr_wait); 1477 } 1478 mutex_unlock(&port->mutex); 1479 } 1480 1481 static int uart_port_activate(struct tty_port *port, struct tty_struct *tty) 1482 { 1483 return 0; 1484 } 1485 1486 static void uart_port_shutdown(struct tty_port *port) 1487 { 1488 struct uart_state *state = container_of(port, struct uart_state, port); 1489 struct uart_port *uport = state->uart_port; 1490 1491 /* 1492 * clear delta_msr_wait queue to avoid mem leaks: we may free 1493 * the irq here so the queue might never be woken up. Note 1494 * that we won't end up waiting on delta_msr_wait again since 1495 * any outstanding file descriptors should be pointing at 1496 * hung_up_tty_fops now. 1497 */ 1498 wake_up_interruptible(&port->delta_msr_wait); 1499 1500 /* 1501 * Free the IRQ and disable the port. 1502 */ 1503 uport->ops->shutdown(uport); 1504 1505 /* 1506 * Ensure that the IRQ handler isn't running on another CPU. 1507 */ 1508 synchronize_irq(uport->irq); 1509 } 1510 1511 static int uart_carrier_raised(struct tty_port *port) 1512 { 1513 struct uart_state *state = container_of(port, struct uart_state, port); 1514 struct uart_port *uport = state->uart_port; 1515 int mctrl; 1516 spin_lock_irq(&uport->lock); 1517 uart_enable_ms(uport); 1518 mctrl = uport->ops->get_mctrl(uport); 1519 spin_unlock_irq(&uport->lock); 1520 if (mctrl & TIOCM_CAR) 1521 return 1; 1522 return 0; 1523 } 1524 1525 static void uart_dtr_rts(struct tty_port *port, int onoff) 1526 { 1527 struct uart_state *state = container_of(port, struct uart_state, port); 1528 struct uart_port *uport = state->uart_port; 1529 1530 if (onoff) 1531 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS); 1532 else 1533 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS); 1534 } 1535 1536 /* 1537 * Calls to uart_open are serialised by the tty_lock in 1538 * drivers/tty/tty_io.c:tty_open() 1539 * Note that if this fails, then uart_close() _will_ be called. 1540 * 1541 * In time, we want to scrap the "opening nonpresent ports" 1542 * behaviour and implement an alternative way for setserial 1543 * to set base addresses/ports/types. This will allow us to 1544 * get rid of a certain amount of extra tests. 1545 */ 1546 static int uart_open(struct tty_struct *tty, struct file *filp) 1547 { 1548 struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state; 1549 int retval, line = tty->index; 1550 struct uart_state *state = drv->state + line; 1551 struct tty_port *port = &state->port; 1552 1553 pr_debug("uart_open(%d) called\n", line); 1554 1555 /* 1556 * We take the semaphore here to guarantee that we won't be re-entered 1557 * while allocating the state structure, or while we request any IRQs 1558 * that the driver may need. This also has the nice side-effect that 1559 * it delays the action of uart_hangup, so we can guarantee that 1560 * state->port.tty will always contain something reasonable. 1561 */ 1562 if (mutex_lock_interruptible(&port->mutex)) { 1563 retval = -ERESTARTSYS; 1564 goto end; 1565 } 1566 1567 port->count++; 1568 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) { 1569 retval = -ENXIO; 1570 goto err_dec_count; 1571 } 1572 1573 /* 1574 * Once we set tty->driver_data here, we are guaranteed that 1575 * uart_close() will decrement the driver module use count. 1576 * Any failures from here onwards should not touch the count. 1577 */ 1578 tty->driver_data = state; 1579 state->uart_port->state = state; 1580 state->port.low_latency = 1581 (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0; 1582 tty_port_tty_set(port, tty); 1583 1584 /* 1585 * Start up the serial port. 1586 */ 1587 retval = uart_startup(tty, state, 0); 1588 1589 /* 1590 * If we succeeded, wait until the port is ready. 1591 */ 1592 mutex_unlock(&port->mutex); 1593 if (retval == 0) 1594 retval = tty_port_block_til_ready(port, tty, filp); 1595 1596 end: 1597 return retval; 1598 err_dec_count: 1599 port->count--; 1600 mutex_unlock(&port->mutex); 1601 goto end; 1602 } 1603 1604 static const char *uart_type(struct uart_port *port) 1605 { 1606 const char *str = NULL; 1607 1608 if (port->ops->type) 1609 str = port->ops->type(port); 1610 1611 if (!str) 1612 str = "unknown"; 1613 1614 return str; 1615 } 1616 1617 #ifdef CONFIG_PROC_FS 1618 1619 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i) 1620 { 1621 struct uart_state *state = drv->state + i; 1622 struct tty_port *port = &state->port; 1623 enum uart_pm_state pm_state; 1624 struct uart_port *uport = state->uart_port; 1625 char stat_buf[32]; 1626 unsigned int status; 1627 int mmio; 1628 1629 if (!uport) 1630 return; 1631 1632 mmio = uport->iotype >= UPIO_MEM; 1633 seq_printf(m, "%d: uart:%s %s%08llX irq:%d", 1634 uport->line, uart_type(uport), 1635 mmio ? "mmio:0x" : "port:", 1636 mmio ? (unsigned long long)uport->mapbase 1637 : (unsigned long long)uport->iobase, 1638 uport->irq); 1639 1640 if (uport->type == PORT_UNKNOWN) { 1641 seq_putc(m, '\n'); 1642 return; 1643 } 1644 1645 if (capable(CAP_SYS_ADMIN)) { 1646 mutex_lock(&port->mutex); 1647 pm_state = state->pm_state; 1648 if (pm_state != UART_PM_STATE_ON) 1649 uart_change_pm(state, UART_PM_STATE_ON); 1650 spin_lock_irq(&uport->lock); 1651 status = uport->ops->get_mctrl(uport); 1652 spin_unlock_irq(&uport->lock); 1653 if (pm_state != UART_PM_STATE_ON) 1654 uart_change_pm(state, pm_state); 1655 mutex_unlock(&port->mutex); 1656 1657 seq_printf(m, " tx:%d rx:%d", 1658 uport->icount.tx, uport->icount.rx); 1659 if (uport->icount.frame) 1660 seq_printf(m, " fe:%d", 1661 uport->icount.frame); 1662 if (uport->icount.parity) 1663 seq_printf(m, " pe:%d", 1664 uport->icount.parity); 1665 if (uport->icount.brk) 1666 seq_printf(m, " brk:%d", 1667 uport->icount.brk); 1668 if (uport->icount.overrun) 1669 seq_printf(m, " oe:%d", 1670 uport->icount.overrun); 1671 1672 #define INFOBIT(bit, str) \ 1673 if (uport->mctrl & (bit)) \ 1674 strncat(stat_buf, (str), sizeof(stat_buf) - \ 1675 strlen(stat_buf) - 2) 1676 #define STATBIT(bit, str) \ 1677 if (status & (bit)) \ 1678 strncat(stat_buf, (str), sizeof(stat_buf) - \ 1679 strlen(stat_buf) - 2) 1680 1681 stat_buf[0] = '\0'; 1682 stat_buf[1] = '\0'; 1683 INFOBIT(TIOCM_RTS, "|RTS"); 1684 STATBIT(TIOCM_CTS, "|CTS"); 1685 INFOBIT(TIOCM_DTR, "|DTR"); 1686 STATBIT(TIOCM_DSR, "|DSR"); 1687 STATBIT(TIOCM_CAR, "|CD"); 1688 STATBIT(TIOCM_RNG, "|RI"); 1689 if (stat_buf[0]) 1690 stat_buf[0] = ' '; 1691 1692 seq_puts(m, stat_buf); 1693 } 1694 seq_putc(m, '\n'); 1695 #undef STATBIT 1696 #undef INFOBIT 1697 } 1698 1699 static int uart_proc_show(struct seq_file *m, void *v) 1700 { 1701 struct tty_driver *ttydrv = m->private; 1702 struct uart_driver *drv = ttydrv->driver_state; 1703 int i; 1704 1705 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", 1706 "", "", ""); 1707 for (i = 0; i < drv->nr; i++) 1708 uart_line_info(m, drv, i); 1709 return 0; 1710 } 1711 1712 static int uart_proc_open(struct inode *inode, struct file *file) 1713 { 1714 return single_open(file, uart_proc_show, PDE_DATA(inode)); 1715 } 1716 1717 static const struct file_operations uart_proc_fops = { 1718 .owner = THIS_MODULE, 1719 .open = uart_proc_open, 1720 .read = seq_read, 1721 .llseek = seq_lseek, 1722 .release = single_release, 1723 }; 1724 #endif 1725 1726 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL) 1727 /* 1728 * uart_console_write - write a console message to a serial port 1729 * @port: the port to write the message 1730 * @s: array of characters 1731 * @count: number of characters in string to write 1732 * @write: function to write character to port 1733 */ 1734 void uart_console_write(struct uart_port *port, const char *s, 1735 unsigned int count, 1736 void (*putchar)(struct uart_port *, int)) 1737 { 1738 unsigned int i; 1739 1740 for (i = 0; i < count; i++, s++) { 1741 if (*s == '\n') 1742 putchar(port, '\r'); 1743 putchar(port, *s); 1744 } 1745 } 1746 EXPORT_SYMBOL_GPL(uart_console_write); 1747 1748 /* 1749 * Check whether an invalid uart number has been specified, and 1750 * if so, search for the first available port that does have 1751 * console support. 1752 */ 1753 struct uart_port * __init 1754 uart_get_console(struct uart_port *ports, int nr, struct console *co) 1755 { 1756 int idx = co->index; 1757 1758 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 && 1759 ports[idx].membase == NULL)) 1760 for (idx = 0; idx < nr; idx++) 1761 if (ports[idx].iobase != 0 || 1762 ports[idx].membase != NULL) 1763 break; 1764 1765 co->index = idx; 1766 1767 return ports + idx; 1768 } 1769 1770 /** 1771 * uart_parse_options - Parse serial port baud/parity/bits/flow control. 1772 * @options: pointer to option string 1773 * @baud: pointer to an 'int' variable for the baud rate. 1774 * @parity: pointer to an 'int' variable for the parity. 1775 * @bits: pointer to an 'int' variable for the number of data bits. 1776 * @flow: pointer to an 'int' variable for the flow control character. 1777 * 1778 * uart_parse_options decodes a string containing the serial console 1779 * options. The format of the string is <baud><parity><bits><flow>, 1780 * eg: 115200n8r 1781 */ 1782 void 1783 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow) 1784 { 1785 char *s = options; 1786 1787 *baud = simple_strtoul(s, NULL, 10); 1788 while (*s >= '0' && *s <= '9') 1789 s++; 1790 if (*s) 1791 *parity = *s++; 1792 if (*s) 1793 *bits = *s++ - '0'; 1794 if (*s) 1795 *flow = *s; 1796 } 1797 EXPORT_SYMBOL_GPL(uart_parse_options); 1798 1799 struct baud_rates { 1800 unsigned int rate; 1801 unsigned int cflag; 1802 }; 1803 1804 static const struct baud_rates baud_rates[] = { 1805 { 921600, B921600 }, 1806 { 460800, B460800 }, 1807 { 230400, B230400 }, 1808 { 115200, B115200 }, 1809 { 57600, B57600 }, 1810 { 38400, B38400 }, 1811 { 19200, B19200 }, 1812 { 9600, B9600 }, 1813 { 4800, B4800 }, 1814 { 2400, B2400 }, 1815 { 1200, B1200 }, 1816 { 0, B38400 } 1817 }; 1818 1819 /** 1820 * uart_set_options - setup the serial console parameters 1821 * @port: pointer to the serial ports uart_port structure 1822 * @co: console pointer 1823 * @baud: baud rate 1824 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even) 1825 * @bits: number of data bits 1826 * @flow: flow control character - 'r' (rts) 1827 */ 1828 int 1829 uart_set_options(struct uart_port *port, struct console *co, 1830 int baud, int parity, int bits, int flow) 1831 { 1832 struct ktermios termios; 1833 static struct ktermios dummy; 1834 int i; 1835 1836 /* 1837 * Ensure that the serial console lock is initialised 1838 * early. 1839 * If this port is a console, then the spinlock is already 1840 * initialised. 1841 */ 1842 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) { 1843 spin_lock_init(&port->lock); 1844 lockdep_set_class(&port->lock, &port_lock_key); 1845 } 1846 1847 memset(&termios, 0, sizeof(struct ktermios)); 1848 1849 termios.c_cflag = CREAD | HUPCL | CLOCAL; 1850 1851 /* 1852 * Construct a cflag setting. 1853 */ 1854 for (i = 0; baud_rates[i].rate; i++) 1855 if (baud_rates[i].rate <= baud) 1856 break; 1857 1858 termios.c_cflag |= baud_rates[i].cflag; 1859 1860 if (bits == 7) 1861 termios.c_cflag |= CS7; 1862 else 1863 termios.c_cflag |= CS8; 1864 1865 switch (parity) { 1866 case 'o': case 'O': 1867 termios.c_cflag |= PARODD; 1868 /*fall through*/ 1869 case 'e': case 'E': 1870 termios.c_cflag |= PARENB; 1871 break; 1872 } 1873 1874 if (flow == 'r') 1875 termios.c_cflag |= CRTSCTS; 1876 1877 /* 1878 * some uarts on other side don't support no flow control. 1879 * So we set * DTR in host uart to make them happy 1880 */ 1881 port->mctrl |= TIOCM_DTR; 1882 1883 port->ops->set_termios(port, &termios, &dummy); 1884 /* 1885 * Allow the setting of the UART parameters with a NULL console 1886 * too: 1887 */ 1888 if (co) 1889 co->cflag = termios.c_cflag; 1890 1891 return 0; 1892 } 1893 EXPORT_SYMBOL_GPL(uart_set_options); 1894 #endif /* CONFIG_SERIAL_CORE_CONSOLE */ 1895 1896 /** 1897 * uart_change_pm - set power state of the port 1898 * 1899 * @state: port descriptor 1900 * @pm_state: new state 1901 * 1902 * Locking: port->mutex has to be held 1903 */ 1904 static void uart_change_pm(struct uart_state *state, 1905 enum uart_pm_state pm_state) 1906 { 1907 struct uart_port *port = state->uart_port; 1908 1909 if (state->pm_state != pm_state) { 1910 if (port->ops->pm) 1911 port->ops->pm(port, pm_state, state->pm_state); 1912 state->pm_state = pm_state; 1913 } 1914 } 1915 1916 struct uart_match { 1917 struct uart_port *port; 1918 struct uart_driver *driver; 1919 }; 1920 1921 static int serial_match_port(struct device *dev, void *data) 1922 { 1923 struct uart_match *match = data; 1924 struct tty_driver *tty_drv = match->driver->tty_driver; 1925 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) + 1926 match->port->line; 1927 1928 return dev->devt == devt; /* Actually, only one tty per port */ 1929 } 1930 1931 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport) 1932 { 1933 struct uart_state *state = drv->state + uport->line; 1934 struct tty_port *port = &state->port; 1935 struct device *tty_dev; 1936 struct uart_match match = {uport, drv}; 1937 1938 mutex_lock(&port->mutex); 1939 1940 tty_dev = device_find_child(uport->dev, &match, serial_match_port); 1941 if (device_may_wakeup(tty_dev)) { 1942 if (!enable_irq_wake(uport->irq)) 1943 uport->irq_wake = 1; 1944 put_device(tty_dev); 1945 mutex_unlock(&port->mutex); 1946 return 0; 1947 } 1948 put_device(tty_dev); 1949 1950 if (console_suspend_enabled || !uart_console(uport)) 1951 uport->suspended = 1; 1952 1953 if (port->flags & ASYNC_INITIALIZED) { 1954 const struct uart_ops *ops = uport->ops; 1955 int tries; 1956 1957 if (console_suspend_enabled || !uart_console(uport)) { 1958 set_bit(ASYNCB_SUSPENDED, &port->flags); 1959 clear_bit(ASYNCB_INITIALIZED, &port->flags); 1960 1961 spin_lock_irq(&uport->lock); 1962 ops->stop_tx(uport); 1963 ops->set_mctrl(uport, 0); 1964 ops->stop_rx(uport); 1965 spin_unlock_irq(&uport->lock); 1966 } 1967 1968 /* 1969 * Wait for the transmitter to empty. 1970 */ 1971 for (tries = 3; !ops->tx_empty(uport) && tries; tries--) 1972 msleep(10); 1973 if (!tries) 1974 dev_err(uport->dev, "%s%d: Unable to drain transmitter\n", 1975 drv->dev_name, 1976 drv->tty_driver->name_base + uport->line); 1977 1978 if (console_suspend_enabled || !uart_console(uport)) 1979 ops->shutdown(uport); 1980 } 1981 1982 /* 1983 * Disable the console device before suspending. 1984 */ 1985 if (console_suspend_enabled && uart_console(uport)) 1986 console_stop(uport->cons); 1987 1988 if (console_suspend_enabled || !uart_console(uport)) 1989 uart_change_pm(state, UART_PM_STATE_OFF); 1990 1991 mutex_unlock(&port->mutex); 1992 1993 return 0; 1994 } 1995 1996 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) 1997 { 1998 struct uart_state *state = drv->state + uport->line; 1999 struct tty_port *port = &state->port; 2000 struct device *tty_dev; 2001 struct uart_match match = {uport, drv}; 2002 struct ktermios termios; 2003 2004 mutex_lock(&port->mutex); 2005 2006 tty_dev = device_find_child(uport->dev, &match, serial_match_port); 2007 if (!uport->suspended && device_may_wakeup(tty_dev)) { 2008 if (uport->irq_wake) { 2009 disable_irq_wake(uport->irq); 2010 uport->irq_wake = 0; 2011 } 2012 put_device(tty_dev); 2013 mutex_unlock(&port->mutex); 2014 return 0; 2015 } 2016 put_device(tty_dev); 2017 uport->suspended = 0; 2018 2019 /* 2020 * Re-enable the console device after suspending. 2021 */ 2022 if (uart_console(uport)) { 2023 /* 2024 * First try to use the console cflag setting. 2025 */ 2026 memset(&termios, 0, sizeof(struct ktermios)); 2027 termios.c_cflag = uport->cons->cflag; 2028 2029 /* 2030 * If that's unset, use the tty termios setting. 2031 */ 2032 if (port->tty && termios.c_cflag == 0) 2033 termios = port->tty->termios; 2034 2035 if (console_suspend_enabled) 2036 uart_change_pm(state, UART_PM_STATE_ON); 2037 uport->ops->set_termios(uport, &termios, NULL); 2038 if (console_suspend_enabled) 2039 console_start(uport->cons); 2040 } 2041 2042 if (port->flags & ASYNC_SUSPENDED) { 2043 const struct uart_ops *ops = uport->ops; 2044 int ret; 2045 2046 uart_change_pm(state, UART_PM_STATE_ON); 2047 spin_lock_irq(&uport->lock); 2048 ops->set_mctrl(uport, 0); 2049 spin_unlock_irq(&uport->lock); 2050 if (console_suspend_enabled || !uart_console(uport)) { 2051 /* Protected by port mutex for now */ 2052 struct tty_struct *tty = port->tty; 2053 ret = ops->startup(uport); 2054 if (ret == 0) { 2055 if (tty) 2056 uart_change_speed(tty, state, NULL); 2057 spin_lock_irq(&uport->lock); 2058 ops->set_mctrl(uport, uport->mctrl); 2059 ops->start_tx(uport); 2060 spin_unlock_irq(&uport->lock); 2061 set_bit(ASYNCB_INITIALIZED, &port->flags); 2062 } else { 2063 /* 2064 * Failed to resume - maybe hardware went away? 2065 * Clear the "initialized" flag so we won't try 2066 * to call the low level drivers shutdown method. 2067 */ 2068 uart_shutdown(tty, state); 2069 } 2070 } 2071 2072 clear_bit(ASYNCB_SUSPENDED, &port->flags); 2073 } 2074 2075 mutex_unlock(&port->mutex); 2076 2077 return 0; 2078 } 2079 2080 static inline void 2081 uart_report_port(struct uart_driver *drv, struct uart_port *port) 2082 { 2083 char address[64]; 2084 2085 switch (port->iotype) { 2086 case UPIO_PORT: 2087 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase); 2088 break; 2089 case UPIO_HUB6: 2090 snprintf(address, sizeof(address), 2091 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6); 2092 break; 2093 case UPIO_MEM: 2094 case UPIO_MEM32: 2095 case UPIO_AU: 2096 case UPIO_TSI: 2097 snprintf(address, sizeof(address), 2098 "MMIO 0x%llx", (unsigned long long)port->mapbase); 2099 break; 2100 default: 2101 strlcpy(address, "*unknown*", sizeof(address)); 2102 break; 2103 } 2104 2105 dev_info(port->dev, "%s%d at %s (irq = %d, base_baud = %d) is a %s\n", 2106 drv->dev_name, 2107 drv->tty_driver->name_base + port->line, 2108 address, port->irq, port->uartclk / 16, uart_type(port)); 2109 } 2110 2111 static void 2112 uart_configure_port(struct uart_driver *drv, struct uart_state *state, 2113 struct uart_port *port) 2114 { 2115 unsigned int flags; 2116 2117 /* 2118 * If there isn't a port here, don't do anything further. 2119 */ 2120 if (!port->iobase && !port->mapbase && !port->membase) 2121 return; 2122 2123 /* 2124 * Now do the auto configuration stuff. Note that config_port 2125 * is expected to claim the resources and map the port for us. 2126 */ 2127 flags = 0; 2128 if (port->flags & UPF_AUTO_IRQ) 2129 flags |= UART_CONFIG_IRQ; 2130 if (port->flags & UPF_BOOT_AUTOCONF) { 2131 if (!(port->flags & UPF_FIXED_TYPE)) { 2132 port->type = PORT_UNKNOWN; 2133 flags |= UART_CONFIG_TYPE; 2134 } 2135 port->ops->config_port(port, flags); 2136 } 2137 2138 if (port->type != PORT_UNKNOWN) { 2139 unsigned long flags; 2140 2141 uart_report_port(drv, port); 2142 2143 /* Power up port for set_mctrl() */ 2144 uart_change_pm(state, UART_PM_STATE_ON); 2145 2146 /* 2147 * Ensure that the modem control lines are de-activated. 2148 * keep the DTR setting that is set in uart_set_options() 2149 * We probably don't need a spinlock around this, but 2150 */ 2151 spin_lock_irqsave(&port->lock, flags); 2152 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR); 2153 spin_unlock_irqrestore(&port->lock, flags); 2154 2155 /* 2156 * If this driver supports console, and it hasn't been 2157 * successfully registered yet, try to re-register it. 2158 * It may be that the port was not available. 2159 */ 2160 if (port->cons && !(port->cons->flags & CON_ENABLED)) 2161 register_console(port->cons); 2162 2163 /* 2164 * Power down all ports by default, except the 2165 * console if we have one. 2166 */ 2167 if (!uart_console(port)) 2168 uart_change_pm(state, UART_PM_STATE_OFF); 2169 } 2170 } 2171 2172 #ifdef CONFIG_CONSOLE_POLL 2173 2174 static int uart_poll_init(struct tty_driver *driver, int line, char *options) 2175 { 2176 struct uart_driver *drv = driver->driver_state; 2177 struct uart_state *state = drv->state + line; 2178 struct uart_port *port; 2179 int baud = 9600; 2180 int bits = 8; 2181 int parity = 'n'; 2182 int flow = 'n'; 2183 int ret; 2184 2185 if (!state || !state->uart_port) 2186 return -1; 2187 2188 port = state->uart_port; 2189 if (!(port->ops->poll_get_char && port->ops->poll_put_char)) 2190 return -1; 2191 2192 if (port->ops->poll_init) { 2193 struct tty_port *tport = &state->port; 2194 2195 ret = 0; 2196 mutex_lock(&tport->mutex); 2197 /* 2198 * We don't set ASYNCB_INITIALIZED as we only initialized the 2199 * hw, e.g. state->xmit is still uninitialized. 2200 */ 2201 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags)) 2202 ret = port->ops->poll_init(port); 2203 mutex_unlock(&tport->mutex); 2204 if (ret) 2205 return ret; 2206 } 2207 2208 if (options) { 2209 uart_parse_options(options, &baud, &parity, &bits, &flow); 2210 return uart_set_options(port, NULL, baud, parity, bits, flow); 2211 } 2212 2213 return 0; 2214 } 2215 2216 static int uart_poll_get_char(struct tty_driver *driver, int line) 2217 { 2218 struct uart_driver *drv = driver->driver_state; 2219 struct uart_state *state = drv->state + line; 2220 struct uart_port *port; 2221 2222 if (!state || !state->uart_port) 2223 return -1; 2224 2225 port = state->uart_port; 2226 return port->ops->poll_get_char(port); 2227 } 2228 2229 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch) 2230 { 2231 struct uart_driver *drv = driver->driver_state; 2232 struct uart_state *state = drv->state + line; 2233 struct uart_port *port; 2234 2235 if (!state || !state->uart_port) 2236 return; 2237 2238 port = state->uart_port; 2239 2240 if (ch == '\n') 2241 port->ops->poll_put_char(port, '\r'); 2242 port->ops->poll_put_char(port, ch); 2243 } 2244 #endif 2245 2246 static const struct tty_operations uart_ops = { 2247 .open = uart_open, 2248 .close = uart_close, 2249 .write = uart_write, 2250 .put_char = uart_put_char, 2251 .flush_chars = uart_flush_chars, 2252 .write_room = uart_write_room, 2253 .chars_in_buffer= uart_chars_in_buffer, 2254 .flush_buffer = uart_flush_buffer, 2255 .ioctl = uart_ioctl, 2256 .throttle = uart_throttle, 2257 .unthrottle = uart_unthrottle, 2258 .send_xchar = uart_send_xchar, 2259 .set_termios = uart_set_termios, 2260 .set_ldisc = uart_set_ldisc, 2261 .stop = uart_stop, 2262 .start = uart_start, 2263 .hangup = uart_hangup, 2264 .break_ctl = uart_break_ctl, 2265 .wait_until_sent= uart_wait_until_sent, 2266 #ifdef CONFIG_PROC_FS 2267 .proc_fops = &uart_proc_fops, 2268 #endif 2269 .tiocmget = uart_tiocmget, 2270 .tiocmset = uart_tiocmset, 2271 .get_icount = uart_get_icount, 2272 #ifdef CONFIG_CONSOLE_POLL 2273 .poll_init = uart_poll_init, 2274 .poll_get_char = uart_poll_get_char, 2275 .poll_put_char = uart_poll_put_char, 2276 #endif 2277 }; 2278 2279 static const struct tty_port_operations uart_port_ops = { 2280 .activate = uart_port_activate, 2281 .shutdown = uart_port_shutdown, 2282 .carrier_raised = uart_carrier_raised, 2283 .dtr_rts = uart_dtr_rts, 2284 }; 2285 2286 /** 2287 * uart_register_driver - register a driver with the uart core layer 2288 * @drv: low level driver structure 2289 * 2290 * Register a uart driver with the core driver. We in turn register 2291 * with the tty layer, and initialise the core driver per-port state. 2292 * 2293 * We have a proc file in /proc/tty/driver which is named after the 2294 * normal driver. 2295 * 2296 * drv->port should be NULL, and the per-port structures should be 2297 * registered using uart_add_one_port after this call has succeeded. 2298 */ 2299 int uart_register_driver(struct uart_driver *drv) 2300 { 2301 struct tty_driver *normal; 2302 int i, retval; 2303 2304 BUG_ON(drv->state); 2305 2306 /* 2307 * Maybe we should be using a slab cache for this, especially if 2308 * we have a large number of ports to handle. 2309 */ 2310 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL); 2311 if (!drv->state) 2312 goto out; 2313 2314 normal = alloc_tty_driver(drv->nr); 2315 if (!normal) 2316 goto out_kfree; 2317 2318 drv->tty_driver = normal; 2319 2320 normal->driver_name = drv->driver_name; 2321 normal->name = drv->dev_name; 2322 normal->major = drv->major; 2323 normal->minor_start = drv->minor; 2324 normal->type = TTY_DRIVER_TYPE_SERIAL; 2325 normal->subtype = SERIAL_TYPE_NORMAL; 2326 normal->init_termios = tty_std_termios; 2327 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL; 2328 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600; 2329 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV; 2330 normal->driver_state = drv; 2331 tty_set_operations(normal, &uart_ops); 2332 2333 /* 2334 * Initialise the UART state(s). 2335 */ 2336 for (i = 0; i < drv->nr; i++) { 2337 struct uart_state *state = drv->state + i; 2338 struct tty_port *port = &state->port; 2339 2340 tty_port_init(port); 2341 port->ops = &uart_port_ops; 2342 port->close_delay = HZ / 2; /* .5 seconds */ 2343 port->closing_wait = 30 * HZ;/* 30 seconds */ 2344 } 2345 2346 retval = tty_register_driver(normal); 2347 if (retval >= 0) 2348 return retval; 2349 2350 for (i = 0; i < drv->nr; i++) 2351 tty_port_destroy(&drv->state[i].port); 2352 put_tty_driver(normal); 2353 out_kfree: 2354 kfree(drv->state); 2355 out: 2356 return -ENOMEM; 2357 } 2358 2359 /** 2360 * uart_unregister_driver - remove a driver from the uart core layer 2361 * @drv: low level driver structure 2362 * 2363 * Remove all references to a driver from the core driver. The low 2364 * level driver must have removed all its ports via the 2365 * uart_remove_one_port() if it registered them with uart_add_one_port(). 2366 * (ie, drv->port == NULL) 2367 */ 2368 void uart_unregister_driver(struct uart_driver *drv) 2369 { 2370 struct tty_driver *p = drv->tty_driver; 2371 unsigned int i; 2372 2373 tty_unregister_driver(p); 2374 put_tty_driver(p); 2375 for (i = 0; i < drv->nr; i++) 2376 tty_port_destroy(&drv->state[i].port); 2377 kfree(drv->state); 2378 drv->state = NULL; 2379 drv->tty_driver = NULL; 2380 } 2381 2382 struct tty_driver *uart_console_device(struct console *co, int *index) 2383 { 2384 struct uart_driver *p = co->data; 2385 *index = co->index; 2386 return p->tty_driver; 2387 } 2388 2389 static ssize_t uart_get_attr_uartclk(struct device *dev, 2390 struct device_attribute *attr, char *buf) 2391 { 2392 struct serial_struct tmp; 2393 struct tty_port *port = dev_get_drvdata(dev); 2394 2395 uart_get_info(port, &tmp); 2396 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16); 2397 } 2398 2399 static ssize_t uart_get_attr_type(struct device *dev, 2400 struct device_attribute *attr, char *buf) 2401 { 2402 struct serial_struct tmp; 2403 struct tty_port *port = dev_get_drvdata(dev); 2404 2405 uart_get_info(port, &tmp); 2406 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type); 2407 } 2408 static ssize_t uart_get_attr_line(struct device *dev, 2409 struct device_attribute *attr, char *buf) 2410 { 2411 struct serial_struct tmp; 2412 struct tty_port *port = dev_get_drvdata(dev); 2413 2414 uart_get_info(port, &tmp); 2415 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line); 2416 } 2417 2418 static ssize_t uart_get_attr_port(struct device *dev, 2419 struct device_attribute *attr, char *buf) 2420 { 2421 struct serial_struct tmp; 2422 struct tty_port *port = dev_get_drvdata(dev); 2423 unsigned long ioaddr; 2424 2425 uart_get_info(port, &tmp); 2426 ioaddr = tmp.port; 2427 if (HIGH_BITS_OFFSET) 2428 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET; 2429 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr); 2430 } 2431 2432 static ssize_t uart_get_attr_irq(struct device *dev, 2433 struct device_attribute *attr, char *buf) 2434 { 2435 struct serial_struct tmp; 2436 struct tty_port *port = dev_get_drvdata(dev); 2437 2438 uart_get_info(port, &tmp); 2439 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq); 2440 } 2441 2442 static ssize_t uart_get_attr_flags(struct device *dev, 2443 struct device_attribute *attr, char *buf) 2444 { 2445 struct serial_struct tmp; 2446 struct tty_port *port = dev_get_drvdata(dev); 2447 2448 uart_get_info(port, &tmp); 2449 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags); 2450 } 2451 2452 static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev, 2453 struct device_attribute *attr, char *buf) 2454 { 2455 struct serial_struct tmp; 2456 struct tty_port *port = dev_get_drvdata(dev); 2457 2458 uart_get_info(port, &tmp); 2459 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size); 2460 } 2461 2462 2463 static ssize_t uart_get_attr_close_delay(struct device *dev, 2464 struct device_attribute *attr, char *buf) 2465 { 2466 struct serial_struct tmp; 2467 struct tty_port *port = dev_get_drvdata(dev); 2468 2469 uart_get_info(port, &tmp); 2470 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay); 2471 } 2472 2473 2474 static ssize_t uart_get_attr_closing_wait(struct device *dev, 2475 struct device_attribute *attr, char *buf) 2476 { 2477 struct serial_struct tmp; 2478 struct tty_port *port = dev_get_drvdata(dev); 2479 2480 uart_get_info(port, &tmp); 2481 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait); 2482 } 2483 2484 static ssize_t uart_get_attr_custom_divisor(struct device *dev, 2485 struct device_attribute *attr, char *buf) 2486 { 2487 struct serial_struct tmp; 2488 struct tty_port *port = dev_get_drvdata(dev); 2489 2490 uart_get_info(port, &tmp); 2491 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor); 2492 } 2493 2494 static ssize_t uart_get_attr_io_type(struct device *dev, 2495 struct device_attribute *attr, char *buf) 2496 { 2497 struct serial_struct tmp; 2498 struct tty_port *port = dev_get_drvdata(dev); 2499 2500 uart_get_info(port, &tmp); 2501 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type); 2502 } 2503 2504 static ssize_t uart_get_attr_iomem_base(struct device *dev, 2505 struct device_attribute *attr, char *buf) 2506 { 2507 struct serial_struct tmp; 2508 struct tty_port *port = dev_get_drvdata(dev); 2509 2510 uart_get_info(port, &tmp); 2511 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base); 2512 } 2513 2514 static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev, 2515 struct device_attribute *attr, char *buf) 2516 { 2517 struct serial_struct tmp; 2518 struct tty_port *port = dev_get_drvdata(dev); 2519 2520 uart_get_info(port, &tmp); 2521 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift); 2522 } 2523 2524 static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL); 2525 static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL); 2526 static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL); 2527 static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL); 2528 static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL); 2529 static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL); 2530 static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL); 2531 static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL); 2532 static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL); 2533 static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL); 2534 static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL); 2535 static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL); 2536 static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL); 2537 2538 static struct attribute *tty_dev_attrs[] = { 2539 &dev_attr_type.attr, 2540 &dev_attr_line.attr, 2541 &dev_attr_port.attr, 2542 &dev_attr_irq.attr, 2543 &dev_attr_flags.attr, 2544 &dev_attr_xmit_fifo_size.attr, 2545 &dev_attr_uartclk.attr, 2546 &dev_attr_close_delay.attr, 2547 &dev_attr_closing_wait.attr, 2548 &dev_attr_custom_divisor.attr, 2549 &dev_attr_io_type.attr, 2550 &dev_attr_iomem_base.attr, 2551 &dev_attr_iomem_reg_shift.attr, 2552 NULL, 2553 }; 2554 2555 static const struct attribute_group tty_dev_attr_group = { 2556 .attrs = tty_dev_attrs, 2557 }; 2558 2559 /** 2560 * uart_add_one_port - attach a driver-defined port structure 2561 * @drv: pointer to the uart low level driver structure for this port 2562 * @uport: uart port structure to use for this port. 2563 * 2564 * This allows the driver to register its own uart_port structure 2565 * with the core driver. The main purpose is to allow the low 2566 * level uart drivers to expand uart_port, rather than having yet 2567 * more levels of structures. 2568 */ 2569 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport) 2570 { 2571 struct uart_state *state; 2572 struct tty_port *port; 2573 int ret = 0; 2574 struct device *tty_dev; 2575 int num_groups; 2576 2577 BUG_ON(in_interrupt()); 2578 2579 if (uport->line >= drv->nr) 2580 return -EINVAL; 2581 2582 state = drv->state + uport->line; 2583 port = &state->port; 2584 2585 mutex_lock(&port_mutex); 2586 mutex_lock(&port->mutex); 2587 if (state->uart_port) { 2588 ret = -EINVAL; 2589 goto out; 2590 } 2591 2592 state->uart_port = uport; 2593 state->pm_state = UART_PM_STATE_UNDEFINED; 2594 2595 uport->cons = drv->cons; 2596 uport->state = state; 2597 2598 /* 2599 * If this port is a console, then the spinlock is already 2600 * initialised. 2601 */ 2602 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) { 2603 spin_lock_init(&uport->lock); 2604 lockdep_set_class(&uport->lock, &port_lock_key); 2605 } 2606 if (uport->cons && uport->dev) 2607 of_console_check(uport->dev->of_node, uport->cons->name, uport->line); 2608 2609 uart_configure_port(drv, state, uport); 2610 2611 num_groups = 2; 2612 if (uport->attr_group) 2613 num_groups++; 2614 2615 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups), 2616 GFP_KERNEL); 2617 if (!uport->tty_groups) { 2618 ret = -ENOMEM; 2619 goto out; 2620 } 2621 uport->tty_groups[0] = &tty_dev_attr_group; 2622 if (uport->attr_group) 2623 uport->tty_groups[1] = uport->attr_group; 2624 2625 /* 2626 * Register the port whether it's detected or not. This allows 2627 * setserial to be used to alter this port's parameters. 2628 */ 2629 tty_dev = tty_port_register_device_attr(port, drv->tty_driver, 2630 uport->line, uport->dev, port, uport->tty_groups); 2631 if (likely(!IS_ERR(tty_dev))) { 2632 device_set_wakeup_capable(tty_dev, 1); 2633 } else { 2634 dev_err(uport->dev, "Cannot register tty device on line %d\n", 2635 uport->line); 2636 } 2637 2638 /* 2639 * Ensure UPF_DEAD is not set. 2640 */ 2641 uport->flags &= ~UPF_DEAD; 2642 2643 out: 2644 mutex_unlock(&port->mutex); 2645 mutex_unlock(&port_mutex); 2646 2647 return ret; 2648 } 2649 2650 /** 2651 * uart_remove_one_port - detach a driver defined port structure 2652 * @drv: pointer to the uart low level driver structure for this port 2653 * @uport: uart port structure for this port 2654 * 2655 * This unhooks (and hangs up) the specified port structure from the 2656 * core driver. No further calls will be made to the low-level code 2657 * for this port. 2658 */ 2659 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport) 2660 { 2661 struct uart_state *state = drv->state + uport->line; 2662 struct tty_port *port = &state->port; 2663 struct tty_struct *tty; 2664 int ret = 0; 2665 2666 BUG_ON(in_interrupt()); 2667 2668 if (state->uart_port != uport) 2669 dev_alert(uport->dev, "Removing wrong port: %p != %p\n", 2670 state->uart_port, uport); 2671 2672 mutex_lock(&port_mutex); 2673 2674 /* 2675 * Mark the port "dead" - this prevents any opens from 2676 * succeeding while we shut down the port. 2677 */ 2678 mutex_lock(&port->mutex); 2679 if (!state->uart_port) { 2680 mutex_unlock(&port->mutex); 2681 ret = -EINVAL; 2682 goto out; 2683 } 2684 uport->flags |= UPF_DEAD; 2685 mutex_unlock(&port->mutex); 2686 2687 /* 2688 * Remove the devices from the tty layer 2689 */ 2690 tty_unregister_device(drv->tty_driver, uport->line); 2691 2692 tty = tty_port_tty_get(port); 2693 if (tty) { 2694 tty_vhangup(port->tty); 2695 tty_kref_put(tty); 2696 } 2697 2698 /* 2699 * If the port is used as a console, unregister it 2700 */ 2701 if (uart_console(uport)) 2702 unregister_console(uport->cons); 2703 2704 /* 2705 * Free the port IO and memory resources, if any. 2706 */ 2707 if (uport->type != PORT_UNKNOWN) 2708 uport->ops->release_port(uport); 2709 kfree(uport->tty_groups); 2710 2711 /* 2712 * Indicate that there isn't a port here anymore. 2713 */ 2714 uport->type = PORT_UNKNOWN; 2715 2716 state->uart_port = NULL; 2717 out: 2718 mutex_unlock(&port_mutex); 2719 2720 return ret; 2721 } 2722 2723 /* 2724 * Are the two ports equivalent? 2725 */ 2726 int uart_match_port(struct uart_port *port1, struct uart_port *port2) 2727 { 2728 if (port1->iotype != port2->iotype) 2729 return 0; 2730 2731 switch (port1->iotype) { 2732 case UPIO_PORT: 2733 return (port1->iobase == port2->iobase); 2734 case UPIO_HUB6: 2735 return (port1->iobase == port2->iobase) && 2736 (port1->hub6 == port2->hub6); 2737 case UPIO_MEM: 2738 case UPIO_MEM32: 2739 case UPIO_AU: 2740 case UPIO_TSI: 2741 return (port1->mapbase == port2->mapbase); 2742 } 2743 return 0; 2744 } 2745 EXPORT_SYMBOL(uart_match_port); 2746 2747 /** 2748 * uart_handle_dcd_change - handle a change of carrier detect state 2749 * @uport: uart_port structure for the open port 2750 * @status: new carrier detect status, nonzero if active 2751 * 2752 * Caller must hold uport->lock 2753 */ 2754 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status) 2755 { 2756 struct tty_port *port = &uport->state->port; 2757 struct tty_struct *tty = port->tty; 2758 struct tty_ldisc *ld; 2759 2760 lockdep_assert_held_once(&uport->lock); 2761 2762 if (tty) { 2763 ld = tty_ldisc_ref(tty); 2764 if (ld) { 2765 if (ld->ops->dcd_change) 2766 ld->ops->dcd_change(tty, status); 2767 tty_ldisc_deref(ld); 2768 } 2769 } 2770 2771 uport->icount.dcd++; 2772 2773 if (uart_dcd_enabled(uport)) { 2774 if (status) 2775 wake_up_interruptible(&port->open_wait); 2776 else if (tty) 2777 tty_hangup(tty); 2778 } 2779 } 2780 EXPORT_SYMBOL_GPL(uart_handle_dcd_change); 2781 2782 /** 2783 * uart_handle_cts_change - handle a change of clear-to-send state 2784 * @uport: uart_port structure for the open port 2785 * @status: new clear to send status, nonzero if active 2786 * 2787 * Caller must hold uport->lock 2788 */ 2789 void uart_handle_cts_change(struct uart_port *uport, unsigned int status) 2790 { 2791 lockdep_assert_held_once(&uport->lock); 2792 2793 uport->icount.cts++; 2794 2795 if (uart_cts_enabled(uport)) { 2796 if (uport->hw_stopped) { 2797 if (status) { 2798 uport->hw_stopped = 0; 2799 uport->ops->start_tx(uport); 2800 uart_write_wakeup(uport); 2801 } 2802 } else { 2803 if (!status) { 2804 uport->hw_stopped = 1; 2805 uport->ops->stop_tx(uport); 2806 } 2807 } 2808 } 2809 } 2810 EXPORT_SYMBOL_GPL(uart_handle_cts_change); 2811 2812 /** 2813 * uart_insert_char - push a char to the uart layer 2814 * 2815 * User is responsible to call tty_flip_buffer_push when they are done with 2816 * insertion. 2817 * 2818 * @port: corresponding port 2819 * @status: state of the serial port RX buffer (LSR for 8250) 2820 * @overrun: mask of overrun bits in @status 2821 * @ch: character to push 2822 * @flag: flag for the character (see TTY_NORMAL and friends) 2823 */ 2824 void uart_insert_char(struct uart_port *port, unsigned int status, 2825 unsigned int overrun, unsigned int ch, unsigned int flag) 2826 { 2827 struct tty_port *tport = &port->state->port; 2828 2829 if ((status & port->ignore_status_mask & ~overrun) == 0) 2830 if (tty_insert_flip_char(tport, ch, flag) == 0) 2831 ++port->icount.buf_overrun; 2832 2833 /* 2834 * Overrun is special. Since it's reported immediately, 2835 * it doesn't affect the current character. 2836 */ 2837 if (status & ~port->ignore_status_mask & overrun) 2838 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0) 2839 ++port->icount.buf_overrun; 2840 } 2841 EXPORT_SYMBOL_GPL(uart_insert_char); 2842 2843 EXPORT_SYMBOL(uart_write_wakeup); 2844 EXPORT_SYMBOL(uart_register_driver); 2845 EXPORT_SYMBOL(uart_unregister_driver); 2846 EXPORT_SYMBOL(uart_suspend_port); 2847 EXPORT_SYMBOL(uart_resume_port); 2848 EXPORT_SYMBOL(uart_add_one_port); 2849 EXPORT_SYMBOL(uart_remove_one_port); 2850 2851 MODULE_DESCRIPTION("Serial driver core"); 2852 MODULE_LICENSE("GPL"); 2853