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