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 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 /* 175 * Setup the RTS and DTR signals once the 176 * port is open and ready to respond. 177 */ 178 if (init_hw && C_BAUD(tty)) 179 uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR); 180 } 181 182 /* 183 * This is to allow setserial on this port. People may want to set 184 * port/irq/type and then reconfigure the port properly if it failed 185 * now. 186 */ 187 if (retval && capable(CAP_SYS_ADMIN)) 188 return 1; 189 190 return retval; 191 } 192 193 static int uart_startup(struct tty_struct *tty, struct uart_state *state, 194 int init_hw) 195 { 196 struct tty_port *port = &state->port; 197 int retval; 198 199 if (port->flags & ASYNC_INITIALIZED) 200 return 0; 201 202 /* 203 * Set the TTY IO error marker - we will only clear this 204 * once we have successfully opened the port. 205 */ 206 set_bit(TTY_IO_ERROR, &tty->flags); 207 208 retval = uart_port_startup(tty, state, init_hw); 209 if (!retval) { 210 set_bit(ASYNCB_INITIALIZED, &port->flags); 211 clear_bit(TTY_IO_ERROR, &tty->flags); 212 } else if (retval > 0) 213 retval = 0; 214 215 return retval; 216 } 217 218 /* 219 * This routine will shutdown a serial port; interrupts are disabled, and 220 * DTR is dropped if the hangup on close termio flag is on. Calls to 221 * uart_shutdown are serialised by the per-port semaphore. 222 */ 223 static void uart_shutdown(struct tty_struct *tty, struct uart_state *state) 224 { 225 struct uart_port *uport = state->uart_port; 226 struct tty_port *port = &state->port; 227 228 /* 229 * Set the TTY IO error marker 230 */ 231 if (tty) 232 set_bit(TTY_IO_ERROR, &tty->flags); 233 234 if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) { 235 /* 236 * Turn off DTR and RTS early. 237 */ 238 if (uart_console(uport) && tty) 239 uport->cons->cflag = tty->termios.c_cflag; 240 241 if (!tty || C_HUPCL(tty)) 242 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS); 243 244 uart_port_shutdown(port); 245 } 246 247 /* 248 * It's possible for shutdown to be called after suspend if we get 249 * a DCD drop (hangup) at just the right time. Clear suspended bit so 250 * we don't try to resume a port that has been shutdown. 251 */ 252 clear_bit(ASYNCB_SUSPENDED, &port->flags); 253 254 /* 255 * Free the transmit buffer page. 256 */ 257 if (state->xmit.buf) { 258 free_page((unsigned long)state->xmit.buf); 259 state->xmit.buf = NULL; 260 } 261 } 262 263 /** 264 * uart_update_timeout - update per-port FIFO timeout. 265 * @port: uart_port structure describing the port 266 * @cflag: termios cflag value 267 * @baud: speed of the port 268 * 269 * Set the port FIFO timeout value. The @cflag value should 270 * reflect the actual hardware settings. 271 */ 272 void 273 uart_update_timeout(struct uart_port *port, unsigned int cflag, 274 unsigned int baud) 275 { 276 unsigned int bits; 277 278 /* byte size and parity */ 279 switch (cflag & CSIZE) { 280 case CS5: 281 bits = 7; 282 break; 283 case CS6: 284 bits = 8; 285 break; 286 case CS7: 287 bits = 9; 288 break; 289 default: 290 bits = 10; 291 break; /* CS8 */ 292 } 293 294 if (cflag & CSTOPB) 295 bits++; 296 if (cflag & PARENB) 297 bits++; 298 299 /* 300 * The total number of bits to be transmitted in the fifo. 301 */ 302 bits = bits * port->fifosize; 303 304 /* 305 * Figure the timeout to send the above number of bits. 306 * Add .02 seconds of slop 307 */ 308 port->timeout = (HZ * bits) / baud + HZ/50; 309 } 310 311 EXPORT_SYMBOL(uart_update_timeout); 312 313 /** 314 * uart_get_baud_rate - return baud rate for a particular port 315 * @port: uart_port structure describing the port in question. 316 * @termios: desired termios settings. 317 * @old: old termios (or NULL) 318 * @min: minimum acceptable baud rate 319 * @max: maximum acceptable baud rate 320 * 321 * Decode the termios structure into a numeric baud rate, 322 * taking account of the magic 38400 baud rate (with spd_* 323 * flags), and mapping the %B0 rate to 9600 baud. 324 * 325 * If the new baud rate is invalid, try the old termios setting. 326 * If it's still invalid, we try 9600 baud. 327 * 328 * Update the @termios structure to reflect the baud rate 329 * we're actually going to be using. Don't do this for the case 330 * where B0 is requested ("hang up"). 331 */ 332 unsigned int 333 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, 334 struct ktermios *old, unsigned int min, unsigned int max) 335 { 336 unsigned int try; 337 unsigned int baud; 338 unsigned int altbaud; 339 int hung_up = 0; 340 upf_t flags = port->flags & UPF_SPD_MASK; 341 342 switch (flags) { 343 case UPF_SPD_HI: 344 altbaud = 57600; 345 break; 346 case UPF_SPD_VHI: 347 altbaud = 115200; 348 break; 349 case UPF_SPD_SHI: 350 altbaud = 230400; 351 break; 352 case UPF_SPD_WARP: 353 altbaud = 460800; 354 break; 355 default: 356 altbaud = 38400; 357 break; 358 } 359 360 for (try = 0; try < 2; try++) { 361 baud = tty_termios_baud_rate(termios); 362 363 /* 364 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge... 365 * Die! Die! Die! 366 */ 367 if (try == 0 && baud == 38400) 368 baud = altbaud; 369 370 /* 371 * Special case: B0 rate. 372 */ 373 if (baud == 0) { 374 hung_up = 1; 375 baud = 9600; 376 } 377 378 if (baud >= min && baud <= max) 379 return baud; 380 381 /* 382 * Oops, the quotient was zero. Try again with 383 * the old baud rate if possible. 384 */ 385 termios->c_cflag &= ~CBAUD; 386 if (old) { 387 baud = tty_termios_baud_rate(old); 388 if (!hung_up) 389 tty_termios_encode_baud_rate(termios, 390 baud, baud); 391 old = NULL; 392 continue; 393 } 394 395 /* 396 * As a last resort, if the range cannot be met then clip to 397 * the nearest chip supported rate. 398 */ 399 if (!hung_up) { 400 if (baud <= min) 401 tty_termios_encode_baud_rate(termios, 402 min + 1, min + 1); 403 else 404 tty_termios_encode_baud_rate(termios, 405 max - 1, max - 1); 406 } 407 } 408 /* Should never happen */ 409 WARN_ON(1); 410 return 0; 411 } 412 413 EXPORT_SYMBOL(uart_get_baud_rate); 414 415 /** 416 * uart_get_divisor - return uart clock divisor 417 * @port: uart_port structure describing the port. 418 * @baud: desired baud rate 419 * 420 * Calculate the uart clock divisor for the port. 421 */ 422 unsigned int 423 uart_get_divisor(struct uart_port *port, unsigned int baud) 424 { 425 unsigned int quot; 426 427 /* 428 * Old custom speed handling. 429 */ 430 if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST) 431 quot = port->custom_divisor; 432 else 433 quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud); 434 435 return quot; 436 } 437 438 EXPORT_SYMBOL(uart_get_divisor); 439 440 /* Caller holds port mutex */ 441 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state, 442 struct ktermios *old_termios) 443 { 444 struct uart_port *uport = state->uart_port; 445 struct ktermios *termios; 446 int hw_stopped; 447 448 /* 449 * If we have no tty, termios, or the port does not exist, 450 * then we can't set the parameters for this port. 451 */ 452 if (!tty || uport->type == PORT_UNKNOWN) 453 return; 454 455 termios = &tty->termios; 456 uport->ops->set_termios(uport, termios, old_termios); 457 458 /* 459 * Set modem status enables based on termios cflag 460 */ 461 spin_lock_irq(&uport->lock); 462 if (termios->c_cflag & CRTSCTS) 463 uport->status |= UPSTAT_CTS_ENABLE; 464 else 465 uport->status &= ~UPSTAT_CTS_ENABLE; 466 467 if (termios->c_cflag & CLOCAL) 468 uport->status &= ~UPSTAT_DCD_ENABLE; 469 else 470 uport->status |= UPSTAT_DCD_ENABLE; 471 472 /* reset sw-assisted CTS flow control based on (possibly) new mode */ 473 hw_stopped = uport->hw_stopped; 474 uport->hw_stopped = uart_softcts_mode(uport) && 475 !(uport->ops->get_mctrl(uport) & TIOCM_CTS); 476 if (uport->hw_stopped) { 477 if (!hw_stopped) 478 uport->ops->stop_tx(uport); 479 } else { 480 if (hw_stopped) 481 __uart_start(tty); 482 } 483 spin_unlock_irq(&uport->lock); 484 } 485 486 static int uart_put_char(struct tty_struct *tty, unsigned char c) 487 { 488 struct uart_state *state = tty->driver_data; 489 struct uart_port *port = state->uart_port; 490 struct circ_buf *circ; 491 unsigned long flags; 492 int ret = 0; 493 494 circ = &state->xmit; 495 if (!circ->buf) 496 return 0; 497 498 spin_lock_irqsave(&port->lock, flags); 499 if (uart_circ_chars_free(circ) != 0) { 500 circ->buf[circ->head] = c; 501 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1); 502 ret = 1; 503 } 504 spin_unlock_irqrestore(&port->lock, flags); 505 return ret; 506 } 507 508 static void uart_flush_chars(struct tty_struct *tty) 509 { 510 uart_start(tty); 511 } 512 513 static int uart_write(struct tty_struct *tty, 514 const unsigned char *buf, int count) 515 { 516 struct uart_state *state = tty->driver_data; 517 struct uart_port *port; 518 struct circ_buf *circ; 519 unsigned long flags; 520 int c, ret = 0; 521 522 /* 523 * This means you called this function _after_ the port was 524 * closed. No cookie for you. 525 */ 526 if (!state) { 527 WARN_ON(1); 528 return -EL3HLT; 529 } 530 531 port = state->uart_port; 532 circ = &state->xmit; 533 534 if (!circ->buf) 535 return 0; 536 537 spin_lock_irqsave(&port->lock, flags); 538 while (1) { 539 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE); 540 if (count < c) 541 c = count; 542 if (c <= 0) 543 break; 544 memcpy(circ->buf + circ->head, buf, c); 545 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1); 546 buf += c; 547 count -= c; 548 ret += c; 549 } 550 551 __uart_start(tty); 552 spin_unlock_irqrestore(&port->lock, flags); 553 554 return ret; 555 } 556 557 static int uart_write_room(struct tty_struct *tty) 558 { 559 struct uart_state *state = tty->driver_data; 560 unsigned long flags; 561 int ret; 562 563 spin_lock_irqsave(&state->uart_port->lock, flags); 564 ret = uart_circ_chars_free(&state->xmit); 565 spin_unlock_irqrestore(&state->uart_port->lock, flags); 566 return ret; 567 } 568 569 static int uart_chars_in_buffer(struct tty_struct *tty) 570 { 571 struct uart_state *state = tty->driver_data; 572 unsigned long flags; 573 int ret; 574 575 spin_lock_irqsave(&state->uart_port->lock, flags); 576 ret = uart_circ_chars_pending(&state->xmit); 577 spin_unlock_irqrestore(&state->uart_port->lock, flags); 578 return ret; 579 } 580 581 static void uart_flush_buffer(struct tty_struct *tty) 582 { 583 struct uart_state *state = tty->driver_data; 584 struct uart_port *port; 585 unsigned long flags; 586 587 /* 588 * This means you called this function _after_ the port was 589 * closed. No cookie for you. 590 */ 591 if (!state) { 592 WARN_ON(1); 593 return; 594 } 595 596 port = state->uart_port; 597 pr_debug("uart_flush_buffer(%d) called\n", tty->index); 598 599 spin_lock_irqsave(&port->lock, flags); 600 uart_circ_clear(&state->xmit); 601 if (port->ops->flush_buffer) 602 port->ops->flush_buffer(port); 603 spin_unlock_irqrestore(&port->lock, flags); 604 tty_wakeup(tty); 605 } 606 607 /* 608 * This function is used to send a high-priority XON/XOFF character to 609 * the device 610 */ 611 static void uart_send_xchar(struct tty_struct *tty, char ch) 612 { 613 struct uart_state *state = tty->driver_data; 614 struct uart_port *port = state->uart_port; 615 unsigned long flags; 616 617 if (port->ops->send_xchar) 618 port->ops->send_xchar(port, ch); 619 else { 620 spin_lock_irqsave(&port->lock, flags); 621 port->x_char = ch; 622 if (ch) 623 port->ops->start_tx(port); 624 spin_unlock_irqrestore(&port->lock, flags); 625 } 626 } 627 628 static void uart_throttle(struct tty_struct *tty) 629 { 630 struct uart_state *state = tty->driver_data; 631 struct uart_port *port = state->uart_port; 632 upstat_t mask = 0; 633 634 if (I_IXOFF(tty)) 635 mask |= UPSTAT_AUTOXOFF; 636 if (C_CRTSCTS(tty)) 637 mask |= UPSTAT_AUTORTS; 638 639 if (port->status & mask) { 640 port->ops->throttle(port); 641 mask &= ~port->status; 642 } 643 644 if (mask & UPSTAT_AUTORTS) 645 uart_clear_mctrl(port, TIOCM_RTS); 646 647 if (mask & UPSTAT_AUTOXOFF) 648 uart_send_xchar(tty, STOP_CHAR(tty)); 649 } 650 651 static void uart_unthrottle(struct tty_struct *tty) 652 { 653 struct uart_state *state = tty->driver_data; 654 struct uart_port *port = state->uart_port; 655 upstat_t mask = 0; 656 657 if (I_IXOFF(tty)) 658 mask |= UPSTAT_AUTOXOFF; 659 if (C_CRTSCTS(tty)) 660 mask |= UPSTAT_AUTORTS; 661 662 if (port->status & mask) { 663 port->ops->unthrottle(port); 664 mask &= ~port->status; 665 } 666 667 if (mask & UPSTAT_AUTORTS) 668 uart_set_mctrl(port, TIOCM_RTS); 669 670 if (mask & UPSTAT_AUTOXOFF) 671 uart_send_xchar(tty, START_CHAR(tty)); 672 } 673 674 static void uart_get_info(struct tty_port *port, struct serial_struct *retinfo) 675 { 676 struct uart_state *state = container_of(port, struct uart_state, port); 677 struct uart_port *uport = state->uart_port; 678 679 memset(retinfo, 0, sizeof(*retinfo)); 680 681 /* 682 * Ensure the state we copy is consistent and no hardware changes 683 * occur as we go 684 */ 685 mutex_lock(&port->mutex); 686 retinfo->type = uport->type; 687 retinfo->line = uport->line; 688 retinfo->port = uport->iobase; 689 if (HIGH_BITS_OFFSET) 690 retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET; 691 retinfo->irq = uport->irq; 692 retinfo->flags = uport->flags; 693 retinfo->xmit_fifo_size = uport->fifosize; 694 retinfo->baud_base = uport->uartclk / 16; 695 retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10; 696 retinfo->closing_wait = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ? 697 ASYNC_CLOSING_WAIT_NONE : 698 jiffies_to_msecs(port->closing_wait) / 10; 699 retinfo->custom_divisor = uport->custom_divisor; 700 retinfo->hub6 = uport->hub6; 701 retinfo->io_type = uport->iotype; 702 retinfo->iomem_reg_shift = uport->regshift; 703 retinfo->iomem_base = (void *)(unsigned long)uport->mapbase; 704 mutex_unlock(&port->mutex); 705 } 706 707 static int uart_get_info_user(struct tty_port *port, 708 struct serial_struct __user *retinfo) 709 { 710 struct serial_struct tmp; 711 712 uart_get_info(port, &tmp); 713 714 if (copy_to_user(retinfo, &tmp, sizeof(*retinfo))) 715 return -EFAULT; 716 return 0; 717 } 718 719 static int uart_set_info(struct tty_struct *tty, struct tty_port *port, 720 struct uart_state *state, 721 struct serial_struct *new_info) 722 { 723 struct uart_port *uport = state->uart_port; 724 unsigned long new_port; 725 unsigned int change_irq, change_port, closing_wait; 726 unsigned int old_custom_divisor, close_delay; 727 upf_t old_flags, new_flags; 728 int retval = 0; 729 730 new_port = new_info->port; 731 if (HIGH_BITS_OFFSET) 732 new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET; 733 734 new_info->irq = irq_canonicalize(new_info->irq); 735 close_delay = msecs_to_jiffies(new_info->close_delay * 10); 736 closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ? 737 ASYNC_CLOSING_WAIT_NONE : 738 msecs_to_jiffies(new_info->closing_wait * 10); 739 740 741 change_irq = !(uport->flags & UPF_FIXED_PORT) 742 && new_info->irq != uport->irq; 743 744 /* 745 * Since changing the 'type' of the port changes its resource 746 * allocations, we should treat type changes the same as 747 * IO port changes. 748 */ 749 change_port = !(uport->flags & UPF_FIXED_PORT) 750 && (new_port != uport->iobase || 751 (unsigned long)new_info->iomem_base != uport->mapbase || 752 new_info->hub6 != uport->hub6 || 753 new_info->io_type != uport->iotype || 754 new_info->iomem_reg_shift != uport->regshift || 755 new_info->type != uport->type); 756 757 old_flags = uport->flags; 758 new_flags = new_info->flags; 759 old_custom_divisor = uport->custom_divisor; 760 761 if (!capable(CAP_SYS_ADMIN)) { 762 retval = -EPERM; 763 if (change_irq || change_port || 764 (new_info->baud_base != uport->uartclk / 16) || 765 (close_delay != port->close_delay) || 766 (closing_wait != port->closing_wait) || 767 (new_info->xmit_fifo_size && 768 new_info->xmit_fifo_size != uport->fifosize) || 769 (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0)) 770 goto exit; 771 uport->flags = ((uport->flags & ~UPF_USR_MASK) | 772 (new_flags & UPF_USR_MASK)); 773 uport->custom_divisor = new_info->custom_divisor; 774 goto check_and_exit; 775 } 776 777 /* 778 * Ask the low level driver to verify the settings. 779 */ 780 if (uport->ops->verify_port) 781 retval = uport->ops->verify_port(uport, new_info); 782 783 if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) || 784 (new_info->baud_base < 9600)) 785 retval = -EINVAL; 786 787 if (retval) 788 goto exit; 789 790 if (change_port || change_irq) { 791 retval = -EBUSY; 792 793 /* 794 * Make sure that we are the sole user of this port. 795 */ 796 if (tty_port_users(port) > 1) 797 goto exit; 798 799 /* 800 * We need to shutdown the serial port at the old 801 * port/type/irq combination. 802 */ 803 uart_shutdown(tty, state); 804 } 805 806 if (change_port) { 807 unsigned long old_iobase, old_mapbase; 808 unsigned int old_type, old_iotype, old_hub6, old_shift; 809 810 old_iobase = uport->iobase; 811 old_mapbase = uport->mapbase; 812 old_type = uport->type; 813 old_hub6 = uport->hub6; 814 old_iotype = uport->iotype; 815 old_shift = uport->regshift; 816 817 /* 818 * Free and release old regions 819 */ 820 if (old_type != PORT_UNKNOWN) 821 uport->ops->release_port(uport); 822 823 uport->iobase = new_port; 824 uport->type = new_info->type; 825 uport->hub6 = new_info->hub6; 826 uport->iotype = new_info->io_type; 827 uport->regshift = new_info->iomem_reg_shift; 828 uport->mapbase = (unsigned long)new_info->iomem_base; 829 830 /* 831 * Claim and map the new regions 832 */ 833 if (uport->type != PORT_UNKNOWN) { 834 retval = uport->ops->request_port(uport); 835 } else { 836 /* Always success - Jean II */ 837 retval = 0; 838 } 839 840 /* 841 * If we fail to request resources for the 842 * new port, try to restore the old settings. 843 */ 844 if (retval) { 845 uport->iobase = old_iobase; 846 uport->type = old_type; 847 uport->hub6 = old_hub6; 848 uport->iotype = old_iotype; 849 uport->regshift = old_shift; 850 uport->mapbase = old_mapbase; 851 852 if (old_type != PORT_UNKNOWN) { 853 retval = uport->ops->request_port(uport); 854 /* 855 * If we failed to restore the old settings, 856 * we fail like this. 857 */ 858 if (retval) 859 uport->type = PORT_UNKNOWN; 860 861 /* 862 * We failed anyway. 863 */ 864 retval = -EBUSY; 865 } 866 867 /* Added to return the correct error -Ram Gupta */ 868 goto exit; 869 } 870 } 871 872 if (change_irq) 873 uport->irq = new_info->irq; 874 if (!(uport->flags & UPF_FIXED_PORT)) 875 uport->uartclk = new_info->baud_base * 16; 876 uport->flags = (uport->flags & ~UPF_CHANGE_MASK) | 877 (new_flags & UPF_CHANGE_MASK); 878 uport->custom_divisor = new_info->custom_divisor; 879 port->close_delay = close_delay; 880 port->closing_wait = closing_wait; 881 if (new_info->xmit_fifo_size) 882 uport->fifosize = new_info->xmit_fifo_size; 883 port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0; 884 885 check_and_exit: 886 retval = 0; 887 if (uport->type == PORT_UNKNOWN) 888 goto exit; 889 if (port->flags & ASYNC_INITIALIZED) { 890 if (((old_flags ^ uport->flags) & UPF_SPD_MASK) || 891 old_custom_divisor != uport->custom_divisor) { 892 /* 893 * If they're setting up a custom divisor or speed, 894 * instead of clearing it, then bitch about it. No 895 * need to rate-limit; it's CAP_SYS_ADMIN only. 896 */ 897 if (uport->flags & UPF_SPD_MASK) { 898 dev_notice(uport->dev, 899 "%s sets custom speed on %s. This is deprecated.\n", 900 current->comm, 901 tty_name(port->tty)); 902 } 903 uart_change_speed(tty, state, NULL); 904 } 905 } else 906 retval = uart_startup(tty, state, 1); 907 exit: 908 return retval; 909 } 910 911 static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state, 912 struct serial_struct __user *newinfo) 913 { 914 struct serial_struct new_serial; 915 struct tty_port *port = &state->port; 916 int retval; 917 918 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial))) 919 return -EFAULT; 920 921 /* 922 * This semaphore protects port->count. It is also 923 * very useful to prevent opens. Also, take the 924 * port configuration semaphore to make sure that a 925 * module insertion/removal doesn't change anything 926 * under us. 927 */ 928 mutex_lock(&port->mutex); 929 retval = uart_set_info(tty, port, state, &new_serial); 930 mutex_unlock(&port->mutex); 931 return retval; 932 } 933 934 /** 935 * uart_get_lsr_info - get line status register info 936 * @tty: tty associated with the UART 937 * @state: UART being queried 938 * @value: returned modem value 939 * 940 * Note: uart_ioctl protects us against hangups. 941 */ 942 static int uart_get_lsr_info(struct tty_struct *tty, 943 struct uart_state *state, unsigned int __user *value) 944 { 945 struct uart_port *uport = state->uart_port; 946 unsigned int result; 947 948 result = uport->ops->tx_empty(uport); 949 950 /* 951 * If we're about to load something into the transmit 952 * register, we'll pretend the transmitter isn't empty to 953 * avoid a race condition (depending on when the transmit 954 * interrupt happens). 955 */ 956 if (uport->x_char || 957 ((uart_circ_chars_pending(&state->xmit) > 0) && 958 !uart_tx_stopped(uport))) 959 result &= ~TIOCSER_TEMT; 960 961 return put_user(result, value); 962 } 963 964 static int uart_tiocmget(struct tty_struct *tty) 965 { 966 struct uart_state *state = tty->driver_data; 967 struct tty_port *port = &state->port; 968 struct uart_port *uport = state->uart_port; 969 int result = -EIO; 970 971 mutex_lock(&port->mutex); 972 if (!(tty->flags & (1 << TTY_IO_ERROR))) { 973 result = uport->mctrl; 974 spin_lock_irq(&uport->lock); 975 result |= uport->ops->get_mctrl(uport); 976 spin_unlock_irq(&uport->lock); 977 } 978 mutex_unlock(&port->mutex); 979 980 return result; 981 } 982 983 static int 984 uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear) 985 { 986 struct uart_state *state = tty->driver_data; 987 struct uart_port *uport = state->uart_port; 988 struct tty_port *port = &state->port; 989 int ret = -EIO; 990 991 mutex_lock(&port->mutex); 992 if (!(tty->flags & (1 << TTY_IO_ERROR))) { 993 uart_update_mctrl(uport, set, clear); 994 ret = 0; 995 } 996 mutex_unlock(&port->mutex); 997 return ret; 998 } 999 1000 static int uart_break_ctl(struct tty_struct *tty, int break_state) 1001 { 1002 struct uart_state *state = tty->driver_data; 1003 struct tty_port *port = &state->port; 1004 struct uart_port *uport = state->uart_port; 1005 1006 mutex_lock(&port->mutex); 1007 1008 if (uport->type != PORT_UNKNOWN) 1009 uport->ops->break_ctl(uport, break_state); 1010 1011 mutex_unlock(&port->mutex); 1012 return 0; 1013 } 1014 1015 static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state) 1016 { 1017 struct uart_port *uport = state->uart_port; 1018 struct tty_port *port = &state->port; 1019 int flags, ret; 1020 1021 if (!capable(CAP_SYS_ADMIN)) 1022 return -EPERM; 1023 1024 /* 1025 * Take the per-port semaphore. This prevents count from 1026 * changing, and hence any extra opens of the port while 1027 * we're auto-configuring. 1028 */ 1029 if (mutex_lock_interruptible(&port->mutex)) 1030 return -ERESTARTSYS; 1031 1032 ret = -EBUSY; 1033 if (tty_port_users(port) == 1) { 1034 uart_shutdown(tty, state); 1035 1036 /* 1037 * If we already have a port type configured, 1038 * we must release its resources. 1039 */ 1040 if (uport->type != PORT_UNKNOWN) 1041 uport->ops->release_port(uport); 1042 1043 flags = UART_CONFIG_TYPE; 1044 if (uport->flags & UPF_AUTO_IRQ) 1045 flags |= UART_CONFIG_IRQ; 1046 1047 /* 1048 * This will claim the ports resources if 1049 * a port is found. 1050 */ 1051 uport->ops->config_port(uport, flags); 1052 1053 ret = uart_startup(tty, state, 1); 1054 } 1055 mutex_unlock(&port->mutex); 1056 return ret; 1057 } 1058 1059 static void uart_enable_ms(struct uart_port *uport) 1060 { 1061 /* 1062 * Force modem status interrupts on 1063 */ 1064 if (uport->ops->enable_ms) 1065 uport->ops->enable_ms(uport); 1066 } 1067 1068 /* 1069 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change 1070 * - mask passed in arg for lines of interest 1071 * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking) 1072 * Caller should use TIOCGICOUNT to see which one it was 1073 * 1074 * FIXME: This wants extracting into a common all driver implementation 1075 * of TIOCMWAIT using tty_port. 1076 */ 1077 static int 1078 uart_wait_modem_status(struct uart_state *state, unsigned long arg) 1079 { 1080 struct uart_port *uport = state->uart_port; 1081 struct tty_port *port = &state->port; 1082 DECLARE_WAITQUEUE(wait, current); 1083 struct uart_icount cprev, cnow; 1084 int ret; 1085 1086 /* 1087 * note the counters on entry 1088 */ 1089 spin_lock_irq(&uport->lock); 1090 memcpy(&cprev, &uport->icount, sizeof(struct uart_icount)); 1091 uart_enable_ms(uport); 1092 spin_unlock_irq(&uport->lock); 1093 1094 add_wait_queue(&port->delta_msr_wait, &wait); 1095 for (;;) { 1096 spin_lock_irq(&uport->lock); 1097 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount)); 1098 spin_unlock_irq(&uport->lock); 1099 1100 set_current_state(TASK_INTERRUPTIBLE); 1101 1102 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) || 1103 ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) || 1104 ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) || 1105 ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) { 1106 ret = 0; 1107 break; 1108 } 1109 1110 schedule(); 1111 1112 /* see if a signal did it */ 1113 if (signal_pending(current)) { 1114 ret = -ERESTARTSYS; 1115 break; 1116 } 1117 1118 cprev = cnow; 1119 } 1120 __set_current_state(TASK_RUNNING); 1121 remove_wait_queue(&port->delta_msr_wait, &wait); 1122 1123 return ret; 1124 } 1125 1126 /* 1127 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS) 1128 * Return: write counters to the user passed counter struct 1129 * NB: both 1->0 and 0->1 transitions are counted except for 1130 * RI where only 0->1 is counted. 1131 */ 1132 static int uart_get_icount(struct tty_struct *tty, 1133 struct serial_icounter_struct *icount) 1134 { 1135 struct uart_state *state = tty->driver_data; 1136 struct uart_icount cnow; 1137 struct uart_port *uport = state->uart_port; 1138 1139 spin_lock_irq(&uport->lock); 1140 memcpy(&cnow, &uport->icount, sizeof(struct uart_icount)); 1141 spin_unlock_irq(&uport->lock); 1142 1143 icount->cts = cnow.cts; 1144 icount->dsr = cnow.dsr; 1145 icount->rng = cnow.rng; 1146 icount->dcd = cnow.dcd; 1147 icount->rx = cnow.rx; 1148 icount->tx = cnow.tx; 1149 icount->frame = cnow.frame; 1150 icount->overrun = cnow.overrun; 1151 icount->parity = cnow.parity; 1152 icount->brk = cnow.brk; 1153 icount->buf_overrun = cnow.buf_overrun; 1154 1155 return 0; 1156 } 1157 1158 static int uart_get_rs485_config(struct uart_port *port, 1159 struct serial_rs485 __user *rs485) 1160 { 1161 unsigned long flags; 1162 struct serial_rs485 aux; 1163 1164 spin_lock_irqsave(&port->lock, flags); 1165 aux = port->rs485; 1166 spin_unlock_irqrestore(&port->lock, flags); 1167 1168 if (copy_to_user(rs485, &aux, sizeof(aux))) 1169 return -EFAULT; 1170 1171 return 0; 1172 } 1173 1174 static int uart_set_rs485_config(struct uart_port *port, 1175 struct serial_rs485 __user *rs485_user) 1176 { 1177 struct serial_rs485 rs485; 1178 int ret; 1179 unsigned long flags; 1180 1181 if (!port->rs485_config) 1182 return -ENOIOCTLCMD; 1183 1184 if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user))) 1185 return -EFAULT; 1186 1187 spin_lock_irqsave(&port->lock, flags); 1188 ret = port->rs485_config(port, &rs485); 1189 spin_unlock_irqrestore(&port->lock, flags); 1190 if (ret) 1191 return ret; 1192 1193 if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485))) 1194 return -EFAULT; 1195 1196 return 0; 1197 } 1198 1199 /* 1200 * Called via sys_ioctl. We can use spin_lock_irq() here. 1201 */ 1202 static int 1203 uart_ioctl(struct tty_struct *tty, unsigned int cmd, 1204 unsigned long arg) 1205 { 1206 struct uart_state *state = tty->driver_data; 1207 struct tty_port *port = &state->port; 1208 void __user *uarg = (void __user *)arg; 1209 int ret = -ENOIOCTLCMD; 1210 1211 1212 /* 1213 * These ioctls don't rely on the hardware to be present. 1214 */ 1215 switch (cmd) { 1216 case TIOCGSERIAL: 1217 ret = uart_get_info_user(port, uarg); 1218 break; 1219 1220 case TIOCSSERIAL: 1221 down_write(&tty->termios_rwsem); 1222 ret = uart_set_info_user(tty, state, uarg); 1223 up_write(&tty->termios_rwsem); 1224 break; 1225 1226 case TIOCSERCONFIG: 1227 down_write(&tty->termios_rwsem); 1228 ret = uart_do_autoconfig(tty, state); 1229 up_write(&tty->termios_rwsem); 1230 break; 1231 1232 case TIOCSERGWILD: /* obsolete */ 1233 case TIOCSERSWILD: /* obsolete */ 1234 ret = 0; 1235 break; 1236 } 1237 1238 if (ret != -ENOIOCTLCMD) 1239 goto out; 1240 1241 if (tty->flags & (1 << TTY_IO_ERROR)) { 1242 ret = -EIO; 1243 goto out; 1244 } 1245 1246 /* 1247 * The following should only be used when hardware is present. 1248 */ 1249 switch (cmd) { 1250 case TIOCMIWAIT: 1251 ret = uart_wait_modem_status(state, arg); 1252 break; 1253 } 1254 1255 if (ret != -ENOIOCTLCMD) 1256 goto out; 1257 1258 mutex_lock(&port->mutex); 1259 1260 if (tty->flags & (1 << TTY_IO_ERROR)) { 1261 ret = -EIO; 1262 goto out_up; 1263 } 1264 1265 /* 1266 * All these rely on hardware being present and need to be 1267 * protected against the tty being hung up. 1268 */ 1269 1270 switch (cmd) { 1271 case TIOCSERGETLSR: /* Get line status register */ 1272 ret = uart_get_lsr_info(tty, state, uarg); 1273 break; 1274 1275 case TIOCGRS485: 1276 ret = uart_get_rs485_config(state->uart_port, uarg); 1277 break; 1278 1279 case TIOCSRS485: 1280 ret = uart_set_rs485_config(state->uart_port, uarg); 1281 break; 1282 default: { 1283 struct uart_port *uport = state->uart_port; 1284 if (uport->ops->ioctl) 1285 ret = uport->ops->ioctl(uport, cmd, arg); 1286 break; 1287 } 1288 } 1289 out_up: 1290 mutex_unlock(&port->mutex); 1291 out: 1292 return ret; 1293 } 1294 1295 static void uart_set_ldisc(struct tty_struct *tty) 1296 { 1297 struct uart_state *state = tty->driver_data; 1298 struct uart_port *uport = state->uart_port; 1299 1300 if (uport->ops->set_ldisc) { 1301 mutex_lock(&state->port.mutex); 1302 uport->ops->set_ldisc(uport, &tty->termios); 1303 mutex_unlock(&state->port.mutex); 1304 } 1305 } 1306 1307 static void uart_set_termios(struct tty_struct *tty, 1308 struct ktermios *old_termios) 1309 { 1310 struct uart_state *state = tty->driver_data; 1311 struct uart_port *uport = state->uart_port; 1312 unsigned int cflag = tty->termios.c_cflag; 1313 unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK; 1314 bool sw_changed = false; 1315 1316 /* 1317 * Drivers doing software flow control also need to know 1318 * about changes to these input settings. 1319 */ 1320 if (uport->flags & UPF_SOFT_FLOW) { 1321 iflag_mask |= IXANY|IXON|IXOFF; 1322 sw_changed = 1323 tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] || 1324 tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP]; 1325 } 1326 1327 /* 1328 * These are the bits that are used to setup various 1329 * flags in the low level driver. We can ignore the Bfoo 1330 * bits in c_cflag; c_[io]speed will always be set 1331 * appropriately by set_termios() in tty_ioctl.c 1332 */ 1333 if ((cflag ^ old_termios->c_cflag) == 0 && 1334 tty->termios.c_ospeed == old_termios->c_ospeed && 1335 tty->termios.c_ispeed == old_termios->c_ispeed && 1336 ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 && 1337 !sw_changed) { 1338 return; 1339 } 1340 1341 mutex_lock(&state->port.mutex); 1342 uart_change_speed(tty, state, old_termios); 1343 mutex_unlock(&state->port.mutex); 1344 /* reload cflag from termios; port driver may have overriden flags */ 1345 cflag = tty->termios.c_cflag; 1346 1347 /* Handle transition to B0 status */ 1348 if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD)) 1349 uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR); 1350 /* Handle transition away from B0 status */ 1351 else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) { 1352 unsigned int mask = TIOCM_DTR; 1353 if (!(cflag & CRTSCTS) || !test_bit(TTY_THROTTLED, &tty->flags)) 1354 mask |= TIOCM_RTS; 1355 uart_set_mctrl(uport, mask); 1356 } 1357 } 1358 1359 /* 1360 * Calls to uart_close() are serialised via the tty_lock in 1361 * drivers/tty/tty_io.c:tty_release() 1362 * drivers/tty/tty_io.c:do_tty_hangup() 1363 * This runs from a workqueue and can sleep for a _short_ time only. 1364 */ 1365 static void uart_close(struct tty_struct *tty, struct file *filp) 1366 { 1367 struct uart_state *state = tty->driver_data; 1368 struct tty_port *port; 1369 struct uart_port *uport; 1370 1371 if (!state) { 1372 struct uart_driver *drv = tty->driver->driver_state; 1373 1374 state = drv->state + tty->index; 1375 port = &state->port; 1376 spin_lock_irq(&port->lock); 1377 --port->count; 1378 spin_unlock_irq(&port->lock); 1379 return; 1380 } 1381 1382 uport = state->uart_port; 1383 port = &state->port; 1384 pr_debug("uart_close(%d) called\n", tty->index); 1385 1386 if (!port->count || tty_port_close_start(port, tty, filp) == 0) 1387 return; 1388 1389 /* 1390 * At this point, we stop accepting input. To do this, we 1391 * disable the receive line status interrupts. 1392 */ 1393 if (port->flags & ASYNC_INITIALIZED) { 1394 spin_lock_irq(&uport->lock); 1395 uport->ops->stop_rx(uport); 1396 spin_unlock_irq(&uport->lock); 1397 /* 1398 * Before we drop DTR, make sure the UART transmitter 1399 * has completely drained; this is especially 1400 * important if there is a transmit FIFO! 1401 */ 1402 uart_wait_until_sent(tty, uport->timeout); 1403 } 1404 1405 mutex_lock(&port->mutex); 1406 uart_shutdown(tty, state); 1407 tty_port_tty_set(port, NULL); 1408 1409 spin_lock_irq(&port->lock); 1410 1411 if (port->blocked_open) { 1412 spin_unlock_irq(&port->lock); 1413 if (port->close_delay) 1414 msleep_interruptible(jiffies_to_msecs(port->close_delay)); 1415 spin_lock_irq(&port->lock); 1416 } else if (!uart_console(uport)) { 1417 spin_unlock_irq(&port->lock); 1418 uart_change_pm(state, UART_PM_STATE_OFF); 1419 spin_lock_irq(&port->lock); 1420 } 1421 1422 /* 1423 * Wake up anyone trying to open this port. 1424 */ 1425 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags); 1426 spin_unlock_irq(&port->lock); 1427 wake_up_interruptible(&port->open_wait); 1428 1429 mutex_unlock(&port->mutex); 1430 1431 tty_ldisc_flush(tty); 1432 tty->closing = 0; 1433 } 1434 1435 static void uart_wait_until_sent(struct tty_struct *tty, int timeout) 1436 { 1437 struct uart_state *state = tty->driver_data; 1438 struct uart_port *port = state->uart_port; 1439 unsigned long char_time, expire; 1440 1441 if (port->type == PORT_UNKNOWN || port->fifosize == 0) 1442 return; 1443 1444 /* 1445 * Set the check interval to be 1/5 of the estimated time to 1446 * send a single character, and make it at least 1. The check 1447 * interval should also be less than the timeout. 1448 * 1449 * Note: we have to use pretty tight timings here to satisfy 1450 * the NIST-PCTS. 1451 */ 1452 char_time = (port->timeout - HZ/50) / port->fifosize; 1453 char_time = char_time / 5; 1454 if (char_time == 0) 1455 char_time = 1; 1456 if (timeout && timeout < char_time) 1457 char_time = timeout; 1458 1459 /* 1460 * If the transmitter hasn't cleared in twice the approximate 1461 * amount of time to send the entire FIFO, it probably won't 1462 * ever clear. This assumes the UART isn't doing flow 1463 * control, which is currently the case. Hence, if it ever 1464 * takes longer than port->timeout, this is probably due to a 1465 * UART bug of some kind. So, we clamp the timeout parameter at 1466 * 2*port->timeout. 1467 */ 1468 if (timeout == 0 || timeout > 2 * port->timeout) 1469 timeout = 2 * port->timeout; 1470 1471 expire = jiffies + timeout; 1472 1473 pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n", 1474 port->line, jiffies, expire); 1475 1476 /* 1477 * Check whether the transmitter is empty every 'char_time'. 1478 * 'timeout' / 'expire' give us the maximum amount of time 1479 * we wait. 1480 */ 1481 while (!port->ops->tx_empty(port)) { 1482 msleep_interruptible(jiffies_to_msecs(char_time)); 1483 if (signal_pending(current)) 1484 break; 1485 if (time_after(jiffies, expire)) 1486 break; 1487 } 1488 } 1489 1490 /* 1491 * Calls to uart_hangup() are serialised by the tty_lock in 1492 * drivers/tty/tty_io.c:do_tty_hangup() 1493 * This runs from a workqueue and can sleep for a _short_ time only. 1494 */ 1495 static void uart_hangup(struct tty_struct *tty) 1496 { 1497 struct uart_state *state = tty->driver_data; 1498 struct tty_port *port = &state->port; 1499 unsigned long flags; 1500 1501 pr_debug("uart_hangup(%d)\n", tty->index); 1502 1503 mutex_lock(&port->mutex); 1504 if (port->flags & ASYNC_NORMAL_ACTIVE) { 1505 uart_flush_buffer(tty); 1506 uart_shutdown(tty, state); 1507 spin_lock_irqsave(&port->lock, flags); 1508 port->count = 0; 1509 clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags); 1510 spin_unlock_irqrestore(&port->lock, flags); 1511 tty_port_tty_set(port, NULL); 1512 if (!uart_console(state->uart_port)) 1513 uart_change_pm(state, UART_PM_STATE_OFF); 1514 wake_up_interruptible(&port->open_wait); 1515 wake_up_interruptible(&port->delta_msr_wait); 1516 } 1517 mutex_unlock(&port->mutex); 1518 } 1519 1520 static void uart_port_shutdown(struct tty_port *port) 1521 { 1522 struct uart_state *state = container_of(port, struct uart_state, port); 1523 struct uart_port *uport = state->uart_port; 1524 1525 /* 1526 * clear delta_msr_wait queue to avoid mem leaks: we may free 1527 * the irq here so the queue might never be woken up. Note 1528 * that we won't end up waiting on delta_msr_wait again since 1529 * any outstanding file descriptors should be pointing at 1530 * hung_up_tty_fops now. 1531 */ 1532 wake_up_interruptible(&port->delta_msr_wait); 1533 1534 /* 1535 * Free the IRQ and disable the port. 1536 */ 1537 uport->ops->shutdown(uport); 1538 1539 /* 1540 * Ensure that the IRQ handler isn't running on another CPU. 1541 */ 1542 synchronize_irq(uport->irq); 1543 } 1544 1545 static int uart_carrier_raised(struct tty_port *port) 1546 { 1547 struct uart_state *state = container_of(port, struct uart_state, port); 1548 struct uart_port *uport = state->uart_port; 1549 int mctrl; 1550 spin_lock_irq(&uport->lock); 1551 uart_enable_ms(uport); 1552 mctrl = uport->ops->get_mctrl(uport); 1553 spin_unlock_irq(&uport->lock); 1554 if (mctrl & TIOCM_CAR) 1555 return 1; 1556 return 0; 1557 } 1558 1559 static void uart_dtr_rts(struct tty_port *port, int onoff) 1560 { 1561 struct uart_state *state = container_of(port, struct uart_state, port); 1562 struct uart_port *uport = state->uart_port; 1563 1564 if (onoff) 1565 uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS); 1566 else 1567 uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS); 1568 } 1569 1570 /* 1571 * Calls to uart_open are serialised by the tty_lock in 1572 * drivers/tty/tty_io.c:tty_open() 1573 * Note that if this fails, then uart_close() _will_ be called. 1574 * 1575 * In time, we want to scrap the "opening nonpresent ports" 1576 * behaviour and implement an alternative way for setserial 1577 * to set base addresses/ports/types. This will allow us to 1578 * get rid of a certain amount of extra tests. 1579 */ 1580 static int uart_open(struct tty_struct *tty, struct file *filp) 1581 { 1582 struct uart_driver *drv = tty->driver->driver_state; 1583 int retval, line = tty->index; 1584 struct uart_state *state = drv->state + line; 1585 struct tty_port *port = &state->port; 1586 1587 pr_debug("uart_open(%d) called\n", line); 1588 1589 spin_lock_irq(&port->lock); 1590 ++port->count; 1591 spin_unlock_irq(&port->lock); 1592 1593 /* 1594 * We take the semaphore here to guarantee that we won't be re-entered 1595 * while allocating the state structure, or while we request any IRQs 1596 * that the driver may need. This also has the nice side-effect that 1597 * it delays the action of uart_hangup, so we can guarantee that 1598 * state->port.tty will always contain something reasonable. 1599 */ 1600 if (mutex_lock_interruptible(&port->mutex)) { 1601 retval = -ERESTARTSYS; 1602 goto end; 1603 } 1604 1605 if (!state->uart_port || state->uart_port->flags & UPF_DEAD) { 1606 retval = -ENXIO; 1607 goto err_unlock; 1608 } 1609 1610 tty->driver_data = state; 1611 state->uart_port->state = state; 1612 state->port.low_latency = 1613 (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0; 1614 tty_port_tty_set(port, tty); 1615 1616 /* 1617 * Start up the serial port. 1618 */ 1619 retval = uart_startup(tty, state, 0); 1620 1621 /* 1622 * If we succeeded, wait until the port is ready. 1623 */ 1624 err_unlock: 1625 mutex_unlock(&port->mutex); 1626 if (retval == 0) 1627 retval = tty_port_block_til_ready(port, tty, filp); 1628 end: 1629 return retval; 1630 } 1631 1632 static const char *uart_type(struct uart_port *port) 1633 { 1634 const char *str = NULL; 1635 1636 if (port->ops->type) 1637 str = port->ops->type(port); 1638 1639 if (!str) 1640 str = "unknown"; 1641 1642 return str; 1643 } 1644 1645 #ifdef CONFIG_PROC_FS 1646 1647 static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i) 1648 { 1649 struct uart_state *state = drv->state + i; 1650 struct tty_port *port = &state->port; 1651 enum uart_pm_state pm_state; 1652 struct uart_port *uport = state->uart_port; 1653 char stat_buf[32]; 1654 unsigned int status; 1655 int mmio; 1656 1657 if (!uport) 1658 return; 1659 1660 mmio = uport->iotype >= UPIO_MEM; 1661 seq_printf(m, "%d: uart:%s %s%08llX irq:%d", 1662 uport->line, uart_type(uport), 1663 mmio ? "mmio:0x" : "port:", 1664 mmio ? (unsigned long long)uport->mapbase 1665 : (unsigned long long)uport->iobase, 1666 uport->irq); 1667 1668 if (uport->type == PORT_UNKNOWN) { 1669 seq_putc(m, '\n'); 1670 return; 1671 } 1672 1673 if (capable(CAP_SYS_ADMIN)) { 1674 mutex_lock(&port->mutex); 1675 pm_state = state->pm_state; 1676 if (pm_state != UART_PM_STATE_ON) 1677 uart_change_pm(state, UART_PM_STATE_ON); 1678 spin_lock_irq(&uport->lock); 1679 status = uport->ops->get_mctrl(uport); 1680 spin_unlock_irq(&uport->lock); 1681 if (pm_state != UART_PM_STATE_ON) 1682 uart_change_pm(state, pm_state); 1683 mutex_unlock(&port->mutex); 1684 1685 seq_printf(m, " tx:%d rx:%d", 1686 uport->icount.tx, uport->icount.rx); 1687 if (uport->icount.frame) 1688 seq_printf(m, " fe:%d", uport->icount.frame); 1689 if (uport->icount.parity) 1690 seq_printf(m, " pe:%d", uport->icount.parity); 1691 if (uport->icount.brk) 1692 seq_printf(m, " brk:%d", uport->icount.brk); 1693 if (uport->icount.overrun) 1694 seq_printf(m, " oe:%d", uport->icount.overrun); 1695 1696 #define INFOBIT(bit, str) \ 1697 if (uport->mctrl & (bit)) \ 1698 strncat(stat_buf, (str), sizeof(stat_buf) - \ 1699 strlen(stat_buf) - 2) 1700 #define STATBIT(bit, str) \ 1701 if (status & (bit)) \ 1702 strncat(stat_buf, (str), sizeof(stat_buf) - \ 1703 strlen(stat_buf) - 2) 1704 1705 stat_buf[0] = '\0'; 1706 stat_buf[1] = '\0'; 1707 INFOBIT(TIOCM_RTS, "|RTS"); 1708 STATBIT(TIOCM_CTS, "|CTS"); 1709 INFOBIT(TIOCM_DTR, "|DTR"); 1710 STATBIT(TIOCM_DSR, "|DSR"); 1711 STATBIT(TIOCM_CAR, "|CD"); 1712 STATBIT(TIOCM_RNG, "|RI"); 1713 if (stat_buf[0]) 1714 stat_buf[0] = ' '; 1715 1716 seq_puts(m, stat_buf); 1717 } 1718 seq_putc(m, '\n'); 1719 #undef STATBIT 1720 #undef INFOBIT 1721 } 1722 1723 static int uart_proc_show(struct seq_file *m, void *v) 1724 { 1725 struct tty_driver *ttydrv = m->private; 1726 struct uart_driver *drv = ttydrv->driver_state; 1727 int i; 1728 1729 seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", ""); 1730 for (i = 0; i < drv->nr; i++) 1731 uart_line_info(m, drv, i); 1732 return 0; 1733 } 1734 1735 static int uart_proc_open(struct inode *inode, struct file *file) 1736 { 1737 return single_open(file, uart_proc_show, PDE_DATA(inode)); 1738 } 1739 1740 static const struct file_operations uart_proc_fops = { 1741 .owner = THIS_MODULE, 1742 .open = uart_proc_open, 1743 .read = seq_read, 1744 .llseek = seq_lseek, 1745 .release = single_release, 1746 }; 1747 #endif 1748 1749 #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL) 1750 /** 1751 * uart_console_write - write a console message to a serial port 1752 * @port: the port to write the message 1753 * @s: array of characters 1754 * @count: number of characters in string to write 1755 * @putchar: function to write character to port 1756 */ 1757 void uart_console_write(struct uart_port *port, const char *s, 1758 unsigned int count, 1759 void (*putchar)(struct uart_port *, int)) 1760 { 1761 unsigned int i; 1762 1763 for (i = 0; i < count; i++, s++) { 1764 if (*s == '\n') 1765 putchar(port, '\r'); 1766 putchar(port, *s); 1767 } 1768 } 1769 EXPORT_SYMBOL_GPL(uart_console_write); 1770 1771 /* 1772 * Check whether an invalid uart number has been specified, and 1773 * if so, search for the first available port that does have 1774 * console support. 1775 */ 1776 struct uart_port * __init 1777 uart_get_console(struct uart_port *ports, int nr, struct console *co) 1778 { 1779 int idx = co->index; 1780 1781 if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 && 1782 ports[idx].membase == NULL)) 1783 for (idx = 0; idx < nr; idx++) 1784 if (ports[idx].iobase != 0 || 1785 ports[idx].membase != NULL) 1786 break; 1787 1788 co->index = idx; 1789 1790 return ports + idx; 1791 } 1792 1793 /** 1794 * uart_parse_earlycon - Parse earlycon options 1795 * @p: ptr to 2nd field (ie., just beyond '<name>,') 1796 * @iotype: ptr for decoded iotype (out) 1797 * @addr: ptr for decoded mapbase/iobase (out) 1798 * @options: ptr for <options> field; NULL if not present (out) 1799 * 1800 * Decodes earlycon kernel command line parameters of the form 1801 * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options> 1802 * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options> 1803 * 1804 * The optional form 1805 * earlycon=<name>,0x<addr>,<options> 1806 * console=<name>,0x<addr>,<options> 1807 * is also accepted; the returned @iotype will be UPIO_MEM. 1808 * 1809 * Returns 0 on success or -EINVAL on failure 1810 */ 1811 int uart_parse_earlycon(char *p, unsigned char *iotype, unsigned long *addr, 1812 char **options) 1813 { 1814 if (strncmp(p, "mmio,", 5) == 0) { 1815 *iotype = UPIO_MEM; 1816 p += 5; 1817 } else if (strncmp(p, "mmio16,", 7) == 0) { 1818 *iotype = UPIO_MEM16; 1819 p += 7; 1820 } else if (strncmp(p, "mmio32,", 7) == 0) { 1821 *iotype = UPIO_MEM32; 1822 p += 7; 1823 } else if (strncmp(p, "mmio32be,", 9) == 0) { 1824 *iotype = UPIO_MEM32BE; 1825 p += 9; 1826 } else if (strncmp(p, "mmio32native,", 13) == 0) { 1827 *iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ? 1828 UPIO_MEM32BE : UPIO_MEM32; 1829 p += 13; 1830 } else if (strncmp(p, "io,", 3) == 0) { 1831 *iotype = UPIO_PORT; 1832 p += 3; 1833 } else if (strncmp(p, "0x", 2) == 0) { 1834 *iotype = UPIO_MEM; 1835 } else { 1836 return -EINVAL; 1837 } 1838 1839 *addr = simple_strtoul(p, NULL, 0); 1840 p = strchr(p, ','); 1841 if (p) 1842 p++; 1843 1844 *options = p; 1845 return 0; 1846 } 1847 EXPORT_SYMBOL_GPL(uart_parse_earlycon); 1848 1849 /** 1850 * uart_parse_options - Parse serial port baud/parity/bits/flow control. 1851 * @options: pointer to option string 1852 * @baud: pointer to an 'int' variable for the baud rate. 1853 * @parity: pointer to an 'int' variable for the parity. 1854 * @bits: pointer to an 'int' variable for the number of data bits. 1855 * @flow: pointer to an 'int' variable for the flow control character. 1856 * 1857 * uart_parse_options decodes a string containing the serial console 1858 * options. The format of the string is <baud><parity><bits><flow>, 1859 * eg: 115200n8r 1860 */ 1861 void 1862 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow) 1863 { 1864 char *s = options; 1865 1866 *baud = simple_strtoul(s, NULL, 10); 1867 while (*s >= '0' && *s <= '9') 1868 s++; 1869 if (*s) 1870 *parity = *s++; 1871 if (*s) 1872 *bits = *s++ - '0'; 1873 if (*s) 1874 *flow = *s; 1875 } 1876 EXPORT_SYMBOL_GPL(uart_parse_options); 1877 1878 /** 1879 * uart_set_options - setup the serial console parameters 1880 * @port: pointer to the serial ports uart_port structure 1881 * @co: console pointer 1882 * @baud: baud rate 1883 * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even) 1884 * @bits: number of data bits 1885 * @flow: flow control character - 'r' (rts) 1886 */ 1887 int 1888 uart_set_options(struct uart_port *port, struct console *co, 1889 int baud, int parity, int bits, int flow) 1890 { 1891 struct ktermios termios; 1892 static struct ktermios dummy; 1893 1894 /* 1895 * Ensure that the serial console lock is initialised 1896 * early. 1897 * If this port is a console, then the spinlock is already 1898 * initialised. 1899 */ 1900 if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) { 1901 spin_lock_init(&port->lock); 1902 lockdep_set_class(&port->lock, &port_lock_key); 1903 } 1904 1905 memset(&termios, 0, sizeof(struct ktermios)); 1906 1907 termios.c_cflag |= CREAD | HUPCL | CLOCAL; 1908 tty_termios_encode_baud_rate(&termios, baud, baud); 1909 1910 if (bits == 7) 1911 termios.c_cflag |= CS7; 1912 else 1913 termios.c_cflag |= CS8; 1914 1915 switch (parity) { 1916 case 'o': case 'O': 1917 termios.c_cflag |= PARODD; 1918 /*fall through*/ 1919 case 'e': case 'E': 1920 termios.c_cflag |= PARENB; 1921 break; 1922 } 1923 1924 if (flow == 'r') 1925 termios.c_cflag |= CRTSCTS; 1926 1927 /* 1928 * some uarts on other side don't support no flow control. 1929 * So we set * DTR in host uart to make them happy 1930 */ 1931 port->mctrl |= TIOCM_DTR; 1932 1933 port->ops->set_termios(port, &termios, &dummy); 1934 /* 1935 * Allow the setting of the UART parameters with a NULL console 1936 * too: 1937 */ 1938 if (co) 1939 co->cflag = termios.c_cflag; 1940 1941 return 0; 1942 } 1943 EXPORT_SYMBOL_GPL(uart_set_options); 1944 #endif /* CONFIG_SERIAL_CORE_CONSOLE */ 1945 1946 /** 1947 * uart_change_pm - set power state of the port 1948 * 1949 * @state: port descriptor 1950 * @pm_state: new state 1951 * 1952 * Locking: port->mutex has to be held 1953 */ 1954 static void uart_change_pm(struct uart_state *state, 1955 enum uart_pm_state pm_state) 1956 { 1957 struct uart_port *port = state->uart_port; 1958 1959 if (state->pm_state != pm_state) { 1960 if (port->ops->pm) 1961 port->ops->pm(port, pm_state, state->pm_state); 1962 state->pm_state = pm_state; 1963 } 1964 } 1965 1966 struct uart_match { 1967 struct uart_port *port; 1968 struct uart_driver *driver; 1969 }; 1970 1971 static int serial_match_port(struct device *dev, void *data) 1972 { 1973 struct uart_match *match = data; 1974 struct tty_driver *tty_drv = match->driver->tty_driver; 1975 dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) + 1976 match->port->line; 1977 1978 return dev->devt == devt; /* Actually, only one tty per port */ 1979 } 1980 1981 int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport) 1982 { 1983 struct uart_state *state = drv->state + uport->line; 1984 struct tty_port *port = &state->port; 1985 struct device *tty_dev; 1986 struct uart_match match = {uport, drv}; 1987 1988 mutex_lock(&port->mutex); 1989 1990 tty_dev = device_find_child(uport->dev, &match, serial_match_port); 1991 if (device_may_wakeup(tty_dev)) { 1992 if (!enable_irq_wake(uport->irq)) 1993 uport->irq_wake = 1; 1994 put_device(tty_dev); 1995 mutex_unlock(&port->mutex); 1996 return 0; 1997 } 1998 put_device(tty_dev); 1999 2000 /* Nothing to do if the console is not suspending */ 2001 if (!console_suspend_enabled && uart_console(uport)) 2002 goto unlock; 2003 2004 uport->suspended = 1; 2005 2006 if (port->flags & ASYNC_INITIALIZED) { 2007 const struct uart_ops *ops = uport->ops; 2008 int tries; 2009 2010 set_bit(ASYNCB_SUSPENDED, &port->flags); 2011 clear_bit(ASYNCB_INITIALIZED, &port->flags); 2012 2013 spin_lock_irq(&uport->lock); 2014 ops->stop_tx(uport); 2015 ops->set_mctrl(uport, 0); 2016 ops->stop_rx(uport); 2017 spin_unlock_irq(&uport->lock); 2018 2019 /* 2020 * Wait for the transmitter to empty. 2021 */ 2022 for (tries = 3; !ops->tx_empty(uport) && tries; tries--) 2023 msleep(10); 2024 if (!tries) 2025 dev_err(uport->dev, "%s%d: Unable to drain transmitter\n", 2026 drv->dev_name, 2027 drv->tty_driver->name_base + uport->line); 2028 2029 ops->shutdown(uport); 2030 } 2031 2032 /* 2033 * Disable the console device before suspending. 2034 */ 2035 if (uart_console(uport)) 2036 console_stop(uport->cons); 2037 2038 uart_change_pm(state, UART_PM_STATE_OFF); 2039 unlock: 2040 mutex_unlock(&port->mutex); 2041 2042 return 0; 2043 } 2044 2045 int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) 2046 { 2047 struct uart_state *state = drv->state + uport->line; 2048 struct tty_port *port = &state->port; 2049 struct device *tty_dev; 2050 struct uart_match match = {uport, drv}; 2051 struct ktermios termios; 2052 2053 mutex_lock(&port->mutex); 2054 2055 tty_dev = device_find_child(uport->dev, &match, serial_match_port); 2056 if (!uport->suspended && device_may_wakeup(tty_dev)) { 2057 if (uport->irq_wake) { 2058 disable_irq_wake(uport->irq); 2059 uport->irq_wake = 0; 2060 } 2061 put_device(tty_dev); 2062 mutex_unlock(&port->mutex); 2063 return 0; 2064 } 2065 put_device(tty_dev); 2066 uport->suspended = 0; 2067 2068 /* 2069 * Re-enable the console device after suspending. 2070 */ 2071 if (uart_console(uport)) { 2072 /* 2073 * First try to use the console cflag setting. 2074 */ 2075 memset(&termios, 0, sizeof(struct ktermios)); 2076 termios.c_cflag = uport->cons->cflag; 2077 2078 /* 2079 * If that's unset, use the tty termios setting. 2080 */ 2081 if (port->tty && termios.c_cflag == 0) 2082 termios = port->tty->termios; 2083 2084 if (console_suspend_enabled) 2085 uart_change_pm(state, UART_PM_STATE_ON); 2086 uport->ops->set_termios(uport, &termios, NULL); 2087 if (console_suspend_enabled) 2088 console_start(uport->cons); 2089 } 2090 2091 if (port->flags & ASYNC_SUSPENDED) { 2092 const struct uart_ops *ops = uport->ops; 2093 int ret; 2094 2095 uart_change_pm(state, UART_PM_STATE_ON); 2096 spin_lock_irq(&uport->lock); 2097 ops->set_mctrl(uport, 0); 2098 spin_unlock_irq(&uport->lock); 2099 if (console_suspend_enabled || !uart_console(uport)) { 2100 /* Protected by port mutex for now */ 2101 struct tty_struct *tty = port->tty; 2102 ret = ops->startup(uport); 2103 if (ret == 0) { 2104 if (tty) 2105 uart_change_speed(tty, state, NULL); 2106 spin_lock_irq(&uport->lock); 2107 ops->set_mctrl(uport, uport->mctrl); 2108 ops->start_tx(uport); 2109 spin_unlock_irq(&uport->lock); 2110 set_bit(ASYNCB_INITIALIZED, &port->flags); 2111 } else { 2112 /* 2113 * Failed to resume - maybe hardware went away? 2114 * Clear the "initialized" flag so we won't try 2115 * to call the low level drivers shutdown method. 2116 */ 2117 uart_shutdown(tty, state); 2118 } 2119 } 2120 2121 clear_bit(ASYNCB_SUSPENDED, &port->flags); 2122 } 2123 2124 mutex_unlock(&port->mutex); 2125 2126 return 0; 2127 } 2128 2129 static inline void 2130 uart_report_port(struct uart_driver *drv, struct uart_port *port) 2131 { 2132 char address[64]; 2133 2134 switch (port->iotype) { 2135 case UPIO_PORT: 2136 snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase); 2137 break; 2138 case UPIO_HUB6: 2139 snprintf(address, sizeof(address), 2140 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6); 2141 break; 2142 case UPIO_MEM: 2143 case UPIO_MEM16: 2144 case UPIO_MEM32: 2145 case UPIO_MEM32BE: 2146 case UPIO_AU: 2147 case UPIO_TSI: 2148 snprintf(address, sizeof(address), 2149 "MMIO 0x%llx", (unsigned long long)port->mapbase); 2150 break; 2151 default: 2152 strlcpy(address, "*unknown*", sizeof(address)); 2153 break; 2154 } 2155 2156 printk(KERN_INFO "%s%s%s%d at %s (irq = %d, base_baud = %d) is a %s\n", 2157 port->dev ? dev_name(port->dev) : "", 2158 port->dev ? ": " : "", 2159 drv->dev_name, 2160 drv->tty_driver->name_base + port->line, 2161 address, port->irq, port->uartclk / 16, uart_type(port)); 2162 } 2163 2164 static void 2165 uart_configure_port(struct uart_driver *drv, struct uart_state *state, 2166 struct uart_port *port) 2167 { 2168 unsigned int flags; 2169 2170 /* 2171 * If there isn't a port here, don't do anything further. 2172 */ 2173 if (!port->iobase && !port->mapbase && !port->membase) 2174 return; 2175 2176 /* 2177 * Now do the auto configuration stuff. Note that config_port 2178 * is expected to claim the resources and map the port for us. 2179 */ 2180 flags = 0; 2181 if (port->flags & UPF_AUTO_IRQ) 2182 flags |= UART_CONFIG_IRQ; 2183 if (port->flags & UPF_BOOT_AUTOCONF) { 2184 if (!(port->flags & UPF_FIXED_TYPE)) { 2185 port->type = PORT_UNKNOWN; 2186 flags |= UART_CONFIG_TYPE; 2187 } 2188 port->ops->config_port(port, flags); 2189 } 2190 2191 if (port->type != PORT_UNKNOWN) { 2192 unsigned long flags; 2193 2194 uart_report_port(drv, port); 2195 2196 /* Power up port for set_mctrl() */ 2197 uart_change_pm(state, UART_PM_STATE_ON); 2198 2199 /* 2200 * Ensure that the modem control lines are de-activated. 2201 * keep the DTR setting that is set in uart_set_options() 2202 * We probably don't need a spinlock around this, but 2203 */ 2204 spin_lock_irqsave(&port->lock, flags); 2205 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR); 2206 spin_unlock_irqrestore(&port->lock, flags); 2207 2208 /* 2209 * If this driver supports console, and it hasn't been 2210 * successfully registered yet, try to re-register it. 2211 * It may be that the port was not available. 2212 */ 2213 if (port->cons && !(port->cons->flags & CON_ENABLED)) 2214 register_console(port->cons); 2215 2216 /* 2217 * Power down all ports by default, except the 2218 * console if we have one. 2219 */ 2220 if (!uart_console(port)) 2221 uart_change_pm(state, UART_PM_STATE_OFF); 2222 } 2223 } 2224 2225 #ifdef CONFIG_CONSOLE_POLL 2226 2227 static int uart_poll_init(struct tty_driver *driver, int line, char *options) 2228 { 2229 struct uart_driver *drv = driver->driver_state; 2230 struct uart_state *state = drv->state + line; 2231 struct uart_port *port; 2232 int baud = 9600; 2233 int bits = 8; 2234 int parity = 'n'; 2235 int flow = 'n'; 2236 int ret; 2237 2238 if (!state || !state->uart_port) 2239 return -1; 2240 2241 port = state->uart_port; 2242 if (!(port->ops->poll_get_char && port->ops->poll_put_char)) 2243 return -1; 2244 2245 if (port->ops->poll_init) { 2246 struct tty_port *tport = &state->port; 2247 2248 ret = 0; 2249 mutex_lock(&tport->mutex); 2250 /* 2251 * We don't set ASYNCB_INITIALIZED as we only initialized the 2252 * hw, e.g. state->xmit is still uninitialized. 2253 */ 2254 if (!test_bit(ASYNCB_INITIALIZED, &tport->flags)) 2255 ret = port->ops->poll_init(port); 2256 mutex_unlock(&tport->mutex); 2257 if (ret) 2258 return ret; 2259 } 2260 2261 if (options) { 2262 uart_parse_options(options, &baud, &parity, &bits, &flow); 2263 return uart_set_options(port, NULL, baud, parity, bits, flow); 2264 } 2265 2266 return 0; 2267 } 2268 2269 static int uart_poll_get_char(struct tty_driver *driver, int line) 2270 { 2271 struct uart_driver *drv = driver->driver_state; 2272 struct uart_state *state = drv->state + line; 2273 struct uart_port *port; 2274 2275 if (!state || !state->uart_port) 2276 return -1; 2277 2278 port = state->uart_port; 2279 return port->ops->poll_get_char(port); 2280 } 2281 2282 static void uart_poll_put_char(struct tty_driver *driver, int line, char ch) 2283 { 2284 struct uart_driver *drv = driver->driver_state; 2285 struct uart_state *state = drv->state + line; 2286 struct uart_port *port; 2287 2288 if (!state || !state->uart_port) 2289 return; 2290 2291 port = state->uart_port; 2292 2293 if (ch == '\n') 2294 port->ops->poll_put_char(port, '\r'); 2295 port->ops->poll_put_char(port, ch); 2296 } 2297 #endif 2298 2299 static const struct tty_operations uart_ops = { 2300 .open = uart_open, 2301 .close = uart_close, 2302 .write = uart_write, 2303 .put_char = uart_put_char, 2304 .flush_chars = uart_flush_chars, 2305 .write_room = uart_write_room, 2306 .chars_in_buffer= uart_chars_in_buffer, 2307 .flush_buffer = uart_flush_buffer, 2308 .ioctl = uart_ioctl, 2309 .throttle = uart_throttle, 2310 .unthrottle = uart_unthrottle, 2311 .send_xchar = uart_send_xchar, 2312 .set_termios = uart_set_termios, 2313 .set_ldisc = uart_set_ldisc, 2314 .stop = uart_stop, 2315 .start = uart_start, 2316 .hangup = uart_hangup, 2317 .break_ctl = uart_break_ctl, 2318 .wait_until_sent= uart_wait_until_sent, 2319 #ifdef CONFIG_PROC_FS 2320 .proc_fops = &uart_proc_fops, 2321 #endif 2322 .tiocmget = uart_tiocmget, 2323 .tiocmset = uart_tiocmset, 2324 .get_icount = uart_get_icount, 2325 #ifdef CONFIG_CONSOLE_POLL 2326 .poll_init = uart_poll_init, 2327 .poll_get_char = uart_poll_get_char, 2328 .poll_put_char = uart_poll_put_char, 2329 #endif 2330 }; 2331 2332 static const struct tty_port_operations uart_port_ops = { 2333 .carrier_raised = uart_carrier_raised, 2334 .dtr_rts = uart_dtr_rts, 2335 }; 2336 2337 /** 2338 * uart_register_driver - register a driver with the uart core layer 2339 * @drv: low level driver structure 2340 * 2341 * Register a uart driver with the core driver. We in turn register 2342 * with the tty layer, and initialise the core driver per-port state. 2343 * 2344 * We have a proc file in /proc/tty/driver which is named after the 2345 * normal driver. 2346 * 2347 * drv->port should be NULL, and the per-port structures should be 2348 * registered using uart_add_one_port after this call has succeeded. 2349 */ 2350 int uart_register_driver(struct uart_driver *drv) 2351 { 2352 struct tty_driver *normal; 2353 int i, retval; 2354 2355 BUG_ON(drv->state); 2356 2357 /* 2358 * Maybe we should be using a slab cache for this, especially if 2359 * we have a large number of ports to handle. 2360 */ 2361 drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL); 2362 if (!drv->state) 2363 goto out; 2364 2365 normal = alloc_tty_driver(drv->nr); 2366 if (!normal) 2367 goto out_kfree; 2368 2369 drv->tty_driver = normal; 2370 2371 normal->driver_name = drv->driver_name; 2372 normal->name = drv->dev_name; 2373 normal->major = drv->major; 2374 normal->minor_start = drv->minor; 2375 normal->type = TTY_DRIVER_TYPE_SERIAL; 2376 normal->subtype = SERIAL_TYPE_NORMAL; 2377 normal->init_termios = tty_std_termios; 2378 normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL; 2379 normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600; 2380 normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV; 2381 normal->driver_state = drv; 2382 tty_set_operations(normal, &uart_ops); 2383 2384 /* 2385 * Initialise the UART state(s). 2386 */ 2387 for (i = 0; i < drv->nr; i++) { 2388 struct uart_state *state = drv->state + i; 2389 struct tty_port *port = &state->port; 2390 2391 tty_port_init(port); 2392 port->ops = &uart_port_ops; 2393 } 2394 2395 retval = tty_register_driver(normal); 2396 if (retval >= 0) 2397 return retval; 2398 2399 for (i = 0; i < drv->nr; i++) 2400 tty_port_destroy(&drv->state[i].port); 2401 put_tty_driver(normal); 2402 out_kfree: 2403 kfree(drv->state); 2404 out: 2405 return -ENOMEM; 2406 } 2407 2408 /** 2409 * uart_unregister_driver - remove a driver from the uart core layer 2410 * @drv: low level driver structure 2411 * 2412 * Remove all references to a driver from the core driver. The low 2413 * level driver must have removed all its ports via the 2414 * uart_remove_one_port() if it registered them with uart_add_one_port(). 2415 * (ie, drv->port == NULL) 2416 */ 2417 void uart_unregister_driver(struct uart_driver *drv) 2418 { 2419 struct tty_driver *p = drv->tty_driver; 2420 unsigned int i; 2421 2422 tty_unregister_driver(p); 2423 put_tty_driver(p); 2424 for (i = 0; i < drv->nr; i++) 2425 tty_port_destroy(&drv->state[i].port); 2426 kfree(drv->state); 2427 drv->state = NULL; 2428 drv->tty_driver = NULL; 2429 } 2430 2431 struct tty_driver *uart_console_device(struct console *co, int *index) 2432 { 2433 struct uart_driver *p = co->data; 2434 *index = co->index; 2435 return p->tty_driver; 2436 } 2437 2438 static ssize_t uart_get_attr_uartclk(struct device *dev, 2439 struct device_attribute *attr, char *buf) 2440 { 2441 struct serial_struct tmp; 2442 struct tty_port *port = dev_get_drvdata(dev); 2443 2444 uart_get_info(port, &tmp); 2445 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16); 2446 } 2447 2448 static ssize_t uart_get_attr_type(struct device *dev, 2449 struct device_attribute *attr, char *buf) 2450 { 2451 struct serial_struct tmp; 2452 struct tty_port *port = dev_get_drvdata(dev); 2453 2454 uart_get_info(port, &tmp); 2455 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type); 2456 } 2457 static ssize_t uart_get_attr_line(struct device *dev, 2458 struct device_attribute *attr, char *buf) 2459 { 2460 struct serial_struct tmp; 2461 struct tty_port *port = dev_get_drvdata(dev); 2462 2463 uart_get_info(port, &tmp); 2464 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line); 2465 } 2466 2467 static ssize_t uart_get_attr_port(struct device *dev, 2468 struct device_attribute *attr, char *buf) 2469 { 2470 struct serial_struct tmp; 2471 struct tty_port *port = dev_get_drvdata(dev); 2472 unsigned long ioaddr; 2473 2474 uart_get_info(port, &tmp); 2475 ioaddr = tmp.port; 2476 if (HIGH_BITS_OFFSET) 2477 ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET; 2478 return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr); 2479 } 2480 2481 static ssize_t uart_get_attr_irq(struct device *dev, 2482 struct device_attribute *attr, char *buf) 2483 { 2484 struct serial_struct tmp; 2485 struct tty_port *port = dev_get_drvdata(dev); 2486 2487 uart_get_info(port, &tmp); 2488 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq); 2489 } 2490 2491 static ssize_t uart_get_attr_flags(struct device *dev, 2492 struct device_attribute *attr, char *buf) 2493 { 2494 struct serial_struct tmp; 2495 struct tty_port *port = dev_get_drvdata(dev); 2496 2497 uart_get_info(port, &tmp); 2498 return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags); 2499 } 2500 2501 static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev, 2502 struct device_attribute *attr, char *buf) 2503 { 2504 struct serial_struct tmp; 2505 struct tty_port *port = dev_get_drvdata(dev); 2506 2507 uart_get_info(port, &tmp); 2508 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size); 2509 } 2510 2511 2512 static ssize_t uart_get_attr_close_delay(struct device *dev, 2513 struct device_attribute *attr, char *buf) 2514 { 2515 struct serial_struct tmp; 2516 struct tty_port *port = dev_get_drvdata(dev); 2517 2518 uart_get_info(port, &tmp); 2519 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay); 2520 } 2521 2522 2523 static ssize_t uart_get_attr_closing_wait(struct device *dev, 2524 struct device_attribute *attr, char *buf) 2525 { 2526 struct serial_struct tmp; 2527 struct tty_port *port = dev_get_drvdata(dev); 2528 2529 uart_get_info(port, &tmp); 2530 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait); 2531 } 2532 2533 static ssize_t uart_get_attr_custom_divisor(struct device *dev, 2534 struct device_attribute *attr, char *buf) 2535 { 2536 struct serial_struct tmp; 2537 struct tty_port *port = dev_get_drvdata(dev); 2538 2539 uart_get_info(port, &tmp); 2540 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor); 2541 } 2542 2543 static ssize_t uart_get_attr_io_type(struct device *dev, 2544 struct device_attribute *attr, char *buf) 2545 { 2546 struct serial_struct tmp; 2547 struct tty_port *port = dev_get_drvdata(dev); 2548 2549 uart_get_info(port, &tmp); 2550 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type); 2551 } 2552 2553 static ssize_t uart_get_attr_iomem_base(struct device *dev, 2554 struct device_attribute *attr, char *buf) 2555 { 2556 struct serial_struct tmp; 2557 struct tty_port *port = dev_get_drvdata(dev); 2558 2559 uart_get_info(port, &tmp); 2560 return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base); 2561 } 2562 2563 static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev, 2564 struct device_attribute *attr, char *buf) 2565 { 2566 struct serial_struct tmp; 2567 struct tty_port *port = dev_get_drvdata(dev); 2568 2569 uart_get_info(port, &tmp); 2570 return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift); 2571 } 2572 2573 static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL); 2574 static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL); 2575 static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL); 2576 static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL); 2577 static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL); 2578 static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL); 2579 static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL); 2580 static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL); 2581 static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL); 2582 static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL); 2583 static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL); 2584 static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL); 2585 static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL); 2586 2587 static struct attribute *tty_dev_attrs[] = { 2588 &dev_attr_type.attr, 2589 &dev_attr_line.attr, 2590 &dev_attr_port.attr, 2591 &dev_attr_irq.attr, 2592 &dev_attr_flags.attr, 2593 &dev_attr_xmit_fifo_size.attr, 2594 &dev_attr_uartclk.attr, 2595 &dev_attr_close_delay.attr, 2596 &dev_attr_closing_wait.attr, 2597 &dev_attr_custom_divisor.attr, 2598 &dev_attr_io_type.attr, 2599 &dev_attr_iomem_base.attr, 2600 &dev_attr_iomem_reg_shift.attr, 2601 NULL, 2602 }; 2603 2604 static const struct attribute_group tty_dev_attr_group = { 2605 .attrs = tty_dev_attrs, 2606 }; 2607 2608 /** 2609 * uart_add_one_port - attach a driver-defined port structure 2610 * @drv: pointer to the uart low level driver structure for this port 2611 * @uport: uart port structure to use for this port. 2612 * 2613 * This allows the driver to register its own uart_port structure 2614 * with the core driver. The main purpose is to allow the low 2615 * level uart drivers to expand uart_port, rather than having yet 2616 * more levels of structures. 2617 */ 2618 int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport) 2619 { 2620 struct uart_state *state; 2621 struct tty_port *port; 2622 int ret = 0; 2623 struct device *tty_dev; 2624 int num_groups; 2625 2626 BUG_ON(in_interrupt()); 2627 2628 if (uport->line >= drv->nr) 2629 return -EINVAL; 2630 2631 state = drv->state + uport->line; 2632 port = &state->port; 2633 2634 mutex_lock(&port_mutex); 2635 mutex_lock(&port->mutex); 2636 if (state->uart_port) { 2637 ret = -EINVAL; 2638 goto out; 2639 } 2640 2641 /* Link the port to the driver state table and vice versa */ 2642 state->uart_port = uport; 2643 uport->state = state; 2644 2645 state->pm_state = UART_PM_STATE_UNDEFINED; 2646 uport->cons = drv->cons; 2647 uport->minor = drv->tty_driver->minor_start + uport->line; 2648 2649 /* 2650 * If this port is a console, then the spinlock is already 2651 * initialised. 2652 */ 2653 if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) { 2654 spin_lock_init(&uport->lock); 2655 lockdep_set_class(&uport->lock, &port_lock_key); 2656 } 2657 if (uport->cons && uport->dev) 2658 of_console_check(uport->dev->of_node, uport->cons->name, uport->line); 2659 2660 uart_configure_port(drv, state, uport); 2661 2662 num_groups = 2; 2663 if (uport->attr_group) 2664 num_groups++; 2665 2666 uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups), 2667 GFP_KERNEL); 2668 if (!uport->tty_groups) { 2669 ret = -ENOMEM; 2670 goto out; 2671 } 2672 uport->tty_groups[0] = &tty_dev_attr_group; 2673 if (uport->attr_group) 2674 uport->tty_groups[1] = uport->attr_group; 2675 2676 /* 2677 * Register the port whether it's detected or not. This allows 2678 * setserial to be used to alter this port's parameters. 2679 */ 2680 tty_dev = tty_port_register_device_attr(port, drv->tty_driver, 2681 uport->line, uport->dev, port, uport->tty_groups); 2682 if (likely(!IS_ERR(tty_dev))) { 2683 device_set_wakeup_capable(tty_dev, 1); 2684 } else { 2685 dev_err(uport->dev, "Cannot register tty device on line %d\n", 2686 uport->line); 2687 } 2688 2689 /* 2690 * Ensure UPF_DEAD is not set. 2691 */ 2692 uport->flags &= ~UPF_DEAD; 2693 2694 out: 2695 mutex_unlock(&port->mutex); 2696 mutex_unlock(&port_mutex); 2697 2698 return ret; 2699 } 2700 2701 /** 2702 * uart_remove_one_port - detach a driver defined port structure 2703 * @drv: pointer to the uart low level driver structure for this port 2704 * @uport: uart port structure for this port 2705 * 2706 * This unhooks (and hangs up) the specified port structure from the 2707 * core driver. No further calls will be made to the low-level code 2708 * for this port. 2709 */ 2710 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport) 2711 { 2712 struct uart_state *state = drv->state + uport->line; 2713 struct tty_port *port = &state->port; 2714 struct tty_struct *tty; 2715 int ret = 0; 2716 2717 BUG_ON(in_interrupt()); 2718 2719 if (state->uart_port != uport) 2720 dev_alert(uport->dev, "Removing wrong port: %p != %p\n", 2721 state->uart_port, uport); 2722 2723 mutex_lock(&port_mutex); 2724 2725 /* 2726 * Mark the port "dead" - this prevents any opens from 2727 * succeeding while we shut down the port. 2728 */ 2729 mutex_lock(&port->mutex); 2730 if (!state->uart_port) { 2731 mutex_unlock(&port->mutex); 2732 ret = -EINVAL; 2733 goto out; 2734 } 2735 uport->flags |= UPF_DEAD; 2736 mutex_unlock(&port->mutex); 2737 2738 /* 2739 * Remove the devices from the tty layer 2740 */ 2741 tty_unregister_device(drv->tty_driver, uport->line); 2742 2743 tty = tty_port_tty_get(port); 2744 if (tty) { 2745 tty_vhangup(port->tty); 2746 tty_kref_put(tty); 2747 } 2748 2749 /* 2750 * If the port is used as a console, unregister it 2751 */ 2752 if (uart_console(uport)) 2753 unregister_console(uport->cons); 2754 2755 /* 2756 * Free the port IO and memory resources, if any. 2757 */ 2758 if (uport->type != PORT_UNKNOWN) 2759 uport->ops->release_port(uport); 2760 kfree(uport->tty_groups); 2761 2762 /* 2763 * Indicate that there isn't a port here anymore. 2764 */ 2765 uport->type = PORT_UNKNOWN; 2766 2767 state->uart_port = NULL; 2768 out: 2769 mutex_unlock(&port_mutex); 2770 2771 return ret; 2772 } 2773 2774 /* 2775 * Are the two ports equivalent? 2776 */ 2777 int uart_match_port(struct uart_port *port1, struct uart_port *port2) 2778 { 2779 if (port1->iotype != port2->iotype) 2780 return 0; 2781 2782 switch (port1->iotype) { 2783 case UPIO_PORT: 2784 return (port1->iobase == port2->iobase); 2785 case UPIO_HUB6: 2786 return (port1->iobase == port2->iobase) && 2787 (port1->hub6 == port2->hub6); 2788 case UPIO_MEM: 2789 case UPIO_MEM16: 2790 case UPIO_MEM32: 2791 case UPIO_MEM32BE: 2792 case UPIO_AU: 2793 case UPIO_TSI: 2794 return (port1->mapbase == port2->mapbase); 2795 } 2796 return 0; 2797 } 2798 EXPORT_SYMBOL(uart_match_port); 2799 2800 /** 2801 * uart_handle_dcd_change - handle a change of carrier detect state 2802 * @uport: uart_port structure for the open port 2803 * @status: new carrier detect status, nonzero if active 2804 * 2805 * Caller must hold uport->lock 2806 */ 2807 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status) 2808 { 2809 struct tty_port *port = &uport->state->port; 2810 struct tty_struct *tty = port->tty; 2811 struct tty_ldisc *ld; 2812 2813 lockdep_assert_held_once(&uport->lock); 2814 2815 if (tty) { 2816 ld = tty_ldisc_ref(tty); 2817 if (ld) { 2818 if (ld->ops->dcd_change) 2819 ld->ops->dcd_change(tty, status); 2820 tty_ldisc_deref(ld); 2821 } 2822 } 2823 2824 uport->icount.dcd++; 2825 2826 if (uart_dcd_enabled(uport)) { 2827 if (status) 2828 wake_up_interruptible(&port->open_wait); 2829 else if (tty) 2830 tty_hangup(tty); 2831 } 2832 } 2833 EXPORT_SYMBOL_GPL(uart_handle_dcd_change); 2834 2835 /** 2836 * uart_handle_cts_change - handle a change of clear-to-send state 2837 * @uport: uart_port structure for the open port 2838 * @status: new clear to send status, nonzero if active 2839 * 2840 * Caller must hold uport->lock 2841 */ 2842 void uart_handle_cts_change(struct uart_port *uport, unsigned int status) 2843 { 2844 lockdep_assert_held_once(&uport->lock); 2845 2846 uport->icount.cts++; 2847 2848 if (uart_softcts_mode(uport)) { 2849 if (uport->hw_stopped) { 2850 if (status) { 2851 uport->hw_stopped = 0; 2852 uport->ops->start_tx(uport); 2853 uart_write_wakeup(uport); 2854 } 2855 } else { 2856 if (!status) { 2857 uport->hw_stopped = 1; 2858 uport->ops->stop_tx(uport); 2859 } 2860 } 2861 2862 } 2863 } 2864 EXPORT_SYMBOL_GPL(uart_handle_cts_change); 2865 2866 /** 2867 * uart_insert_char - push a char to the uart layer 2868 * 2869 * User is responsible to call tty_flip_buffer_push when they are done with 2870 * insertion. 2871 * 2872 * @port: corresponding port 2873 * @status: state of the serial port RX buffer (LSR for 8250) 2874 * @overrun: mask of overrun bits in @status 2875 * @ch: character to push 2876 * @flag: flag for the character (see TTY_NORMAL and friends) 2877 */ 2878 void uart_insert_char(struct uart_port *port, unsigned int status, 2879 unsigned int overrun, unsigned int ch, unsigned int flag) 2880 { 2881 struct tty_port *tport = &port->state->port; 2882 2883 if ((status & port->ignore_status_mask & ~overrun) == 0) 2884 if (tty_insert_flip_char(tport, ch, flag) == 0) 2885 ++port->icount.buf_overrun; 2886 2887 /* 2888 * Overrun is special. Since it's reported immediately, 2889 * it doesn't affect the current character. 2890 */ 2891 if (status & ~port->ignore_status_mask & overrun) 2892 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0) 2893 ++port->icount.buf_overrun; 2894 } 2895 EXPORT_SYMBOL_GPL(uart_insert_char); 2896 2897 EXPORT_SYMBOL(uart_write_wakeup); 2898 EXPORT_SYMBOL(uart_register_driver); 2899 EXPORT_SYMBOL(uart_unregister_driver); 2900 EXPORT_SYMBOL(uart_suspend_port); 2901 EXPORT_SYMBOL(uart_resume_port); 2902 EXPORT_SYMBOL(uart_add_one_port); 2903 EXPORT_SYMBOL(uart_remove_one_port); 2904 2905 MODULE_DESCRIPTION("Serial driver core"); 2906 MODULE_LICENSE("GPL"); 2907