drivers/serial/serial_core.c

   1 /*
   2  *  linux/drivers/char/core.c
   3  *
   4  *  Driver core for serial ports
   5  *
   6  *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
   7  *
   8  *  Copyright 1999 ARM Limited
   9  *  Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  24  */
  25 #include <linux/module.h>
  26 #include <linux/tty.h>
  27 #include <linux/slab.h>
  28 #include <linux/init.h>
  29 #include <linux/console.h>
  30 #include <linux/serial_core.h>
  31 #include <linux/smp_lock.h>
  32 #include <linux/device.h>
  33 #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
  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  */
  43 static DEFINE_MUTEX(port_mutex);
  44
  45 /*
  46  * lockdep: port->lock is initialized in two places, but we
  47  *          want only one lock-class:
  48  */
  49 static struct lock_class_key port_lock_key;
  50
  51 #define HIGH_BITS_OFFSET        ((sizeof(long)-sizeof(int))*8)
  52
  53 #define uart_users(state)       ((state)->count + ((state)->info ? (state)->info->blocked_open : 0))
  54
  55 #ifdef CONFIG_SERIAL_CORE_CONSOLE
  56 #define uart_console(port)      ((port)->cons && (port)->cons->index == (port)->line)
  57 #else
  58 #define uart_console(port)      (0)
  59 #endif
  60
  61 static void uart_change_speed(struct uart_state *state,
  62                                         struct ktermios *old_termios);
  63 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
  64 static void uart_change_pm(struct uart_state *state, int pm_state);
  65
  66 /*
  67  * This routine is used by the interrupt handler to schedule processing in
  68  * the software interrupt portion of the driver.
  69  */
  70 void uart_write_wakeup(struct uart_port *port)
  71 {
  72         struct uart_info *info = port->info;
  73         /*
  74          * This means you called this function _after_ the port was
  75          * closed.  No cookie for you.
  76          */
  77         BUG_ON(!info);
  78         tasklet_schedule(&info->tlet);
  79 }
  80
  81 static void uart_stop(struct tty_struct *tty)
  82 {
  83         struct uart_state *state = tty->driver_data;
  84         struct uart_port *port = state->port;
  85         unsigned long flags;
  86
  87         spin_lock_irqsave(&port->lock, flags);
  88         port->ops->stop_tx(port);
  89         spin_unlock_irqrestore(&port->lock, flags);
  90 }
  91
  92 static void __uart_start(struct tty_struct *tty)
  93 {
  94         struct uart_state *state = tty->driver_data;
  95         struct uart_port *port = state->port;
  96
  97         if (!uart_circ_empty(&state->info->xmit) && state->info->xmit.buf &&
  98             !tty->stopped && !tty->hw_stopped)
  99                 port->ops->start_tx(port);
 100 }
 101
 102 static void uart_start(struct tty_struct *tty)
 103 {
 104         struct uart_state *state = tty->driver_data;
 105         struct uart_port *port = state->port;
 106         unsigned long flags;
 107
 108         spin_lock_irqsave(&port->lock, flags);
 109         __uart_start(tty);
 110         spin_unlock_irqrestore(&port->lock, flags);
 111 }
 112
 113 static void uart_tasklet_action(unsigned long data)
 114 {
 115         struct uart_state *state = (struct uart_state *)data;
 116         tty_wakeup(state->info->tty);
 117 }
 118
 119 static inline void
 120 uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
 121 {
 122         unsigned long flags;
 123         unsigned int old;
 124
 125         spin_lock_irqsave(&port->lock, flags);
 126         old = port->mctrl;
 127         port->mctrl = (old & ~clear) | set;
 128         if (old != port->mctrl)
 129                 port->ops->set_mctrl(port, port->mctrl);
 130         spin_unlock_irqrestore(&port->lock, flags);
 131 }
 132
 133 #define uart_set_mctrl(port, set)       uart_update_mctrl(port, set, 0)
 134 #define uart_clear_mctrl(port, clear)   uart_update_mctrl(port, 0, clear)
 135
 136 /*
 137  * Startup the port.  This will be called once per open.  All calls
 138  * will be serialised by the per-port semaphore.
 139  */
 140 static int uart_startup(struct uart_state *state, int init_hw)
 141 {
 142         struct uart_info *info = state->info;
 143         struct uart_port *port = state->port;
 144         unsigned long page;
 145         int retval = 0;
 146
 147         if (info->flags & UIF_INITIALIZED)
 148                 return 0;
 149
 150         /*
 151          * Set the TTY IO error marker - we will only clear this
 152          * once we have successfully opened the port.  Also set
 153          * up the tty->alt_speed kludge
 154          */
 155         set_bit(TTY_IO_ERROR, &info->tty->flags);
 156
 157         if (port->type == PORT_UNKNOWN)
 158                 return 0;
 159
 160         /*
 161          * Initialise and allocate the transmit and temporary
 162          * buffer.
 163          */
 164         if (!info->xmit.buf) {
 165                 page = get_zeroed_page(GFP_KERNEL);
 166                 if (!page)
 167                         return -ENOMEM;
 168
 169                 info->xmit.buf = (unsigned char *) page;
 170                 uart_circ_clear(&info->xmit);
 171         }
 172
 173         retval = port->ops->startup(port);
 174         if (retval == 0) {
 175                 if (init_hw) {
 176                         /*
 177                          * Initialise the hardware port settings.
 178                          */
 179                         uart_change_speed(state, NULL);
 180
 181                         /*
 182                          * Setup the RTS and DTR signals once the
 183                          * port is open and ready to respond.
 184                          */
 185                         if (info->tty->termios->c_cflag & CBAUD)
 186                                 uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR);
 187                 }
 188
 189                 if (info->flags & UIF_CTS_FLOW) {
 190                         spin_lock_irq(&port->lock);
 191                         if (!(port->ops->get_mctrl(port) & TIOCM_CTS))
 192                                 info->tty->hw_stopped = 1;
 193                         spin_unlock_irq(&port->lock);
 194                 }
 195
 196                 info->flags |= UIF_INITIALIZED;
 197
 198                 clear_bit(TTY_IO_ERROR, &info->tty->flags);
 199         }
 200
 201         if (retval && capable(CAP_SYS_ADMIN))
 202                 retval = 0;
 203
 204         return retval;
 205 }
 206
 207 /*
 208  * This routine will shutdown a serial port; interrupts are disabled, and
 209  * DTR is dropped if the hangup on close termio flag is on.  Calls to
 210  * uart_shutdown are serialised by the per-port semaphore.
 211  */
 212 static void uart_shutdown(struct uart_state *state)
 213 {
 214         struct uart_info *info = state->info;
 215         struct uart_port *port = state->port;
 216
 217         /*
 218          * Set the TTY IO error marker
 219          */
 220         if (info->tty)
 221                 set_bit(TTY_IO_ERROR, &info->tty->flags);
 222
 223         if (info->flags & UIF_INITIALIZED) {
 224                 info->flags &= ~UIF_INITIALIZED;
 225
 226                 /*
 227                  * Turn off DTR and RTS early.
 228                  */
 229                 if (!info->tty || (info->tty->termios->c_cflag & HUPCL))
 230                         uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
 231
 232                 /*
 233                  * clear delta_msr_wait queue to avoid mem leaks: we may free
 234                  * the irq here so the queue might never be woken up.  Note
 235                  * that we won't end up waiting on delta_msr_wait again since
 236                  * any outstanding file descriptors should be pointing at
 237                  * hung_up_tty_fops now.
 238                  */
 239                 wake_up_interruptible(&info->delta_msr_wait);
 240
 241                 /*
 242                  * Free the IRQ and disable the port.
 243                  */
 244                 port->ops->shutdown(port);
 245
 246                 /*
 247                  * Ensure that the IRQ handler isn't running on another CPU.
 248                  */
 249                 synchronize_irq(port->irq);
 250         }
 251
 252         /*
 253          * kill off our tasklet
 254          */
 255         tasklet_kill(&info->tlet);
 256
 257         /*
 258          * Free the transmit buffer page.
 259          */
 260         if (info->xmit.buf) {
 261                 free_page((unsigned long)info->xmit.buf);
 262                 info->xmit.buf = NULL;
 263         }
 264 }
 265
 266 /**
 267  *      uart_update_timeout - update per-port FIFO timeout.
 268  *      @port:  uart_port structure describing the port
 269  *      @cflag: termios cflag value
 270  *      @baud:  speed of the port
 271  *
 272  *      Set the port FIFO timeout value.  The @cflag value should
 273  *      reflect the actual hardware settings.
 274  */
 275 void
 276 uart_update_timeout(struct uart_port *port, unsigned int cflag,
 277                     unsigned int baud)
 278 {
 279         unsigned int bits;
 280
 281         /* byte size and parity */
 282         switch (cflag & CSIZE) {
 283         case CS5:
 284                 bits = 7;
 285                 break;
 286         case CS6:
 287                 bits = 8;
 288                 break;
 289         case CS7:
 290                 bits = 9;
 291                 break;
 292         default:
 293                 bits = 10;
 294                 break; /* CS8 */
 295         }
 296
 297         if (cflag & CSTOPB)
 298                 bits++;
 299         if (cflag & PARENB)
 300                 bits++;
 301
 302         /*
 303          * The total number of bits to be transmitted in the fifo.
 304          */
 305         bits = bits * port->fifosize;
 306
 307         /*
 308          * Figure the timeout to send the above number of bits.
 309          * Add .02 seconds of slop
 310          */
 311         port->timeout = (HZ * bits) / baud + HZ/50;
 312 }
 313
 314 EXPORT_SYMBOL(uart_update_timeout);
 315
 316 /**
 317  *      uart_get_baud_rate - return baud rate for a particular port
 318  *      @port: uart_port structure describing the port in question.
 319  *      @termios: desired termios settings.
 320  *      @old: old termios (or NULL)
 321  *      @min: minimum acceptable baud rate
 322  *      @max: maximum acceptable baud rate
 323  *
 324  *      Decode the termios structure into a numeric baud rate,
 325  *      taking account of the magic 38400 baud rate (with spd_*
 326  *      flags), and mapping the %B0 rate to 9600 baud.
 327  *
 328  *      If the new baud rate is invalid, try the old termios setting.
 329  *      If it's still invalid, we try 9600 baud.
 330  *
 331  *      Update the @termios structure to reflect the baud rate
 332  *      we're actually going to be using.
 333  */
 334 unsigned int
 335 uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
 336                    struct ktermios *old, unsigned int min, unsigned int max)
 337 {
 338         unsigned int try, baud, altbaud = 38400;
 339         upf_t flags = port->flags & UPF_SPD_MASK;
 340
 341         if (flags == UPF_SPD_HI)
 342                 altbaud = 57600;
 343         if (flags == UPF_SPD_VHI)
 344                 altbaud = 115200;
 345         if (flags == UPF_SPD_SHI)
 346                 altbaud = 230400;
 347         if (flags == UPF_SPD_WARP)
 348                 altbaud = 460800;
 349
 350         for (try = 0; try < 2; try++) {
 351                 baud = tty_termios_baud_rate(termios);
 352
 353                 /*
 354                  * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
 355                  * Die! Die! Die!
 356                  */
 357                 if (baud == 38400)
 358                         baud = altbaud;
 359
 360                 /*
 361                  * Special case: B0 rate.
 362                  */
 363                 if (baud == 0)
 364                         baud = 9600;
 365
 366                 if (baud >= min && baud <= max)
 367                         return baud;
 368
 369                 /*
 370                  * Oops, the quotient was zero.  Try again with
 371                  * the old baud rate if possible.
 372                  */
 373                 termios->c_cflag &= ~CBAUD;
 374                 if (old) {
 375                         baud = tty_termios_baud_rate(old);
 376                         tty_termios_encode_baud_rate(termios, baud, baud);
 377                         old = NULL;
 378                         continue;
 379                 }
 380
 381                 /*
 382                  * As a last resort, if the quotient is zero,
 383                  * default to 9600 bps
 384                  */
 385                 tty_termios_encode_baud_rate(termios, 9600, 9600);
 386         }
 387
 388         return 0;
 389 }
 390
 391 EXPORT_SYMBOL(uart_get_baud_rate);
 392
 393 /**
 394  *      uart_get_divisor - return uart clock divisor
 395  *      @port: uart_port structure describing the port.
 396  *      @baud: desired baud rate
 397  *
 398  *      Calculate the uart clock divisor for the port.
 399  */
 400 unsigned int
 401 uart_get_divisor(struct uart_port *port, unsigned int baud)
 402 {
 403         unsigned int quot;
 404
 405         /*
 406          * Old custom speed handling.
 407          */
 408         if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
 409                 quot = port->custom_divisor;
 410         else
 411                 quot = (port->uartclk + (8 * baud)) / (16 * baud);
 412
 413         return quot;
 414 }
 415
 416 EXPORT_SYMBOL(uart_get_divisor);
 417
 418 static void
 419 uart_change_speed(struct uart_state *state, struct ktermios *old_termios)
 420 {
 421         struct tty_struct *tty = state->info->tty;
 422         struct uart_port *port = state->port;
 423         struct ktermios *termios;
 424
 425         /*
 426          * If we have no tty, termios, or the port does not exist,
 427          * then we can't set the parameters for this port.
 428          */
 429         if (!tty || !tty->termios || port->type == PORT_UNKNOWN)
 430                 return;
 431
 432         termios = tty->termios;
 433
 434         /*
 435          * Set flags based on termios cflag
 436          */
 437         if (termios->c_cflag & CRTSCTS)
 438                 state->info->flags |= UIF_CTS_FLOW;
 439         else
 440                 state->info->flags &= ~UIF_CTS_FLOW;
 441
 442         if (termios->c_cflag & CLOCAL)
 443                 state->info->flags &= ~UIF_CHECK_CD;
 444         else
 445                 state->info->flags |= UIF_CHECK_CD;
 446
 447         port->ops->set_termios(port, termios, old_termios);
 448 }
 449
 450 static inline void
 451 __uart_put_char(struct uart_port *port, struct circ_buf *circ, unsigned char c)
 452 {
 453         unsigned long flags;
 454
 455         if (!circ->buf)
 456                 return;
 457
 458         spin_lock_irqsave(&port->lock, flags);
 459         if (uart_circ_chars_free(circ) != 0) {
 460                 circ->buf[circ->head] = c;
 461                 circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
 462         }
 463         spin_unlock_irqrestore(&port->lock, flags);
 464 }
 465
 466 static void uart_put_char(struct tty_struct *tty, unsigned char ch)
 467 {
 468         struct uart_state *state = tty->driver_data;
 469
 470         __uart_put_char(state->port, &state->info->xmit, ch);
 471 }
 472
 473 static void uart_flush_chars(struct tty_struct *tty)
 474 {
 475         uart_start(tty);
 476 }
 477
 478 static int
 479 uart_write(struct tty_struct *tty, const unsigned char *buf, int count)
 480 {
 481         struct uart_state *state = tty->driver_data;
 482         struct uart_port *port;
 483         struct circ_buf *circ;
 484         unsigned long flags;
 485         int c, ret = 0;
 486
 487         /*
 488          * This means you called this function _after_ the port was
 489          * closed.  No cookie for you.
 490          */
 491         if (!state || !state->info) {
 492                 WARN_ON(1);
 493                 return -EL3HLT;
 494         }
 495
 496         port = state->port;
 497         circ = &state->info->xmit;
 498
 499         if (!circ->buf)
 500                 return 0;
 501
 502         spin_lock_irqsave(&port->lock, flags);
 503         while (1) {
 504                 c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
 505                 if (count < c)
 506                         c = count;
 507                 if (c <= 0)
 508                         break;
 509                 memcpy(circ->buf + circ->head, buf, c);
 510                 circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
 511                 buf += c;
 512                 count -= c;
 513                 ret += c;
 514         }
 515         spin_unlock_irqrestore(&port->lock, flags);
 516
 517         uart_start(tty);
 518         return ret;
 519 }
 520
 521 static int uart_write_room(struct tty_struct *tty)
 522 {
 523         struct uart_state *state = tty->driver_data;
 524
 525         return uart_circ_chars_free(&state->info->xmit);
 526 }
 527
 528 static int uart_chars_in_buffer(struct tty_struct *tty)
 529 {
 530         struct uart_state *state = tty->driver_data;
 531
 532         return uart_circ_chars_pending(&state->info->xmit);
 533 }
 534
 535 static void uart_flush_buffer(struct tty_struct *tty)
 536 {
 537         struct uart_state *state = tty->driver_data;
 538         struct uart_port *port = state->port;
 539         unsigned long flags;
 540
 541         /*
 542          * This means you called this function _after_ the port was
 543          * closed.  No cookie for you.
 544          */
 545         if (!state || !state->info) {
 546                 WARN_ON(1);
 547                 return;
 548         }
 549
 550         pr_debug("uart_flush_buffer(%d) called\n", tty->index);
 551
 552         spin_lock_irqsave(&port->lock, flags);
 553         uart_circ_clear(&state->info->xmit);
 554         spin_unlock_irqrestore(&port->lock, flags);
 555         tty_wakeup(tty);
 556 }
 557
 558 /*
 559  * This function is used to send a high-priority XON/XOFF character to
 560  * the device
 561  */
 562 static void uart_send_xchar(struct tty_struct *tty, char ch)
 563 {
 564         struct uart_state *state = tty->driver_data;
 565         struct uart_port *port = state->port;
 566         unsigned long flags;
 567
 568         if (port->ops->send_xchar)
 569                 port->ops->send_xchar(port, ch);
 570         else {
 571                 port->x_char = ch;
 572                 if (ch) {
 573                         spin_lock_irqsave(&port->lock, flags);
 574                         port->ops->start_tx(port);
 575                         spin_unlock_irqrestore(&port->lock, flags);
 576                 }
 577         }
 578 }
 579
 580 static void uart_throttle(struct tty_struct *tty)
 581 {
 582         struct uart_state *state = tty->driver_data;
 583
 584         if (I_IXOFF(tty))
 585                 uart_send_xchar(tty, STOP_CHAR(tty));
 586
 587         if (tty->termios->c_cflag & CRTSCTS)
 588                 uart_clear_mctrl(state->port, TIOCM_RTS);
 589 }
 590
 591 static void uart_unthrottle(struct tty_struct *tty)
 592 {
 593         struct uart_state *state = tty->driver_data;
 594         struct uart_port *port = state->port;
 595
 596         if (I_IXOFF(tty)) {
 597                 if (port->x_char)
 598                         port->x_char = 0;
 599                 else
 600                         uart_send_xchar(tty, START_CHAR(tty));
 601         }
 602
 603         if (tty->termios->c_cflag & CRTSCTS)
 604                 uart_set_mctrl(port, TIOCM_RTS);
 605 }
 606
 607 static int uart_get_info(struct uart_state *state,
 608                          struct serial_struct __user *retinfo)
 609 {
 610         struct uart_port *port = state->port;
 611         struct serial_struct tmp;
 612
 613         memset(&tmp, 0, sizeof(tmp));
 614         tmp.type            = port->type;
 615         tmp.line            = port->line;
 616         tmp.port            = port->iobase;
 617         if (HIGH_BITS_OFFSET)
 618                 tmp.port_high = (long) port->iobase >> HIGH_BITS_OFFSET;
 619         tmp.irq             = port->irq;
 620         tmp.flags           = port->flags;
 621         tmp.xmit_fifo_size  = port->fifosize;
 622         tmp.baud_base       = port->uartclk / 16;
 623         tmp.close_delay     = state->close_delay / 10;
 624         tmp.closing_wait    = state->closing_wait == USF_CLOSING_WAIT_NONE ?
 625                                 ASYNC_CLOSING_WAIT_NONE :
 626                                 state->closing_wait / 10;
 627         tmp.custom_divisor  = port->custom_divisor;
 628         tmp.hub6            = port->hub6;
 629         tmp.io_type         = port->iotype;
 630         tmp.iomem_reg_shift = port->regshift;
 631         tmp.iomem_base      = (void *)(unsigned long)port->mapbase;
 632
 633         if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
 634                 return -EFAULT;
 635         return 0;
 636 }
 637
 638 static int uart_set_info(struct uart_state *state,
 639                          struct serial_struct __user *newinfo)
 640 {
 641         struct serial_struct new_serial;
 642         struct uart_port *port = state->port;
 643         unsigned long new_port;
 644         unsigned int change_irq, change_port, closing_wait;
 645         unsigned int old_custom_divisor, close_delay;
 646         upf_t old_flags, new_flags;
 647         int retval = 0;
 648
 649         if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
 650                 return -EFAULT;
 651
 652         new_port = new_serial.port;
 653         if (HIGH_BITS_OFFSET)
 654                 new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET;
 655
 656         new_serial.irq = irq_canonicalize(new_serial.irq);
 657         close_delay = new_serial.close_delay * 10;
 658         closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
 659                         USF_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
 660
 661         /*
 662          * This semaphore protects state->count.  It is also
 663          * very useful to prevent opens.  Also, take the
 664          * port configuration semaphore to make sure that a
 665          * module insertion/removal doesn't change anything
 666          * under us.
 667          */
 668         mutex_lock(&state->mutex);
 669
 670         change_irq  = !(port->flags & UPF_FIXED_PORT)
 671                 && new_serial.irq != port->irq;
 672
 673         /*
 674          * Since changing the 'type' of the port changes its resource
 675          * allocations, we should treat type changes the same as
 676          * IO port changes.
 677          */
 678         change_port = !(port->flags & UPF_FIXED_PORT)
 679                 && (new_port != port->iobase ||
 680                     (unsigned long)new_serial.iomem_base != port->mapbase ||
 681                     new_serial.hub6 != port->hub6 ||
 682                     new_serial.io_type != port->iotype ||
 683                     new_serial.iomem_reg_shift != port->regshift ||
 684                     new_serial.type != port->type);
 685
 686         old_flags = port->flags;
 687         new_flags = new_serial.flags;
 688         old_custom_divisor = port->custom_divisor;
 689
 690         if (!capable(CAP_SYS_ADMIN)) {
 691                 retval = -EPERM;
 692                 if (change_irq || change_port ||
 693                     (new_serial.baud_base != port->uartclk / 16) ||
 694                     (close_delay != state->close_delay) ||
 695                     (closing_wait != state->closing_wait) ||
 696                     (new_serial.xmit_fifo_size &&
 697                      new_serial.xmit_fifo_size != port->fifosize) ||
 698                     (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
 699                         goto exit;
 700                 port->flags = ((port->flags & ~UPF_USR_MASK) |
 701                                (new_flags & UPF_USR_MASK));
 702                 port->custom_divisor = new_serial.custom_divisor;
 703                 goto check_and_exit;
 704         }
 705
 706         /*
 707          * Ask the low level driver to verify the settings.
 708          */
 709         if (port->ops->verify_port)
 710                 retval = port->ops->verify_port(port, &new_serial);
 711
 712         if ((new_serial.irq >= NR_IRQS) || (new_serial.irq < 0) ||
 713             (new_serial.baud_base < 9600))
 714                 retval = -EINVAL;
 715
 716         if (retval)
 717                 goto exit;
 718
 719         if (change_port || change_irq) {
 720                 retval = -EBUSY;
 721
 722                 /*
 723                  * Make sure that we are the sole user of this port.
 724                  */
 725                 if (uart_users(state) > 1)
 726                         goto exit;
 727
 728                 /*
 729                  * We need to shutdown the serial port at the old
 730                  * port/type/irq combination.
 731                  */
 732                 uart_shutdown(state);
 733         }
 734
 735         if (change_port) {
 736                 unsigned long old_iobase, old_mapbase;
 737                 unsigned int old_type, old_iotype, old_hub6, old_shift;
 738
 739                 old_iobase = port->iobase;
 740                 old_mapbase = port->mapbase;
 741                 old_type = port->type;
 742                 old_hub6 = port->hub6;
 743                 old_iotype = port->iotype;
 744                 old_shift = port->regshift;
 745
 746                 /*
 747                  * Free and release old regions
 748                  */
 749                 if (old_type != PORT_UNKNOWN)
 750                         port->ops->release_port(port);
 751
 752                 port->iobase = new_port;
 753                 port->type = new_serial.type;
 754                 port->hub6 = new_serial.hub6;
 755                 port->iotype = new_serial.io_type;
 756                 port->regshift = new_serial.iomem_reg_shift;
 757                 port->mapbase = (unsigned long)new_serial.iomem_base;
 758
 759                 /*
 760                  * Claim and map the new regions
 761                  */
 762                 if (port->type != PORT_UNKNOWN) {
 763                         retval = port->ops->request_port(port);
 764                 } else {
 765                         /* Always success - Jean II */
 766                         retval = 0;
 767                 }
 768
 769                 /*
 770                  * If we fail to request resources for the
 771                  * new port, try to restore the old settings.
 772                  */
 773                 if (retval && old_type != PORT_UNKNOWN) {
 774                         port->iobase = old_iobase;
 775                         port->type = old_type;
 776                         port->hub6 = old_hub6;
 777                         port->iotype = old_iotype;
 778                         port->regshift = old_shift;
 779                         port->mapbase = old_mapbase;
 780                         retval = port->ops->request_port(port);
 781                         /*
 782                          * If we failed to restore the old settings,
 783                          * we fail like this.
 784                          */
 785                         if (retval)
 786                                 port->type = PORT_UNKNOWN;
 787
 788                         /*
 789                          * We failed anyway.
 790                          */
 791                         retval = -EBUSY;
 792                         /* Added to return the correct error -Ram Gupta */
 793                         goto exit;
 794                 }
 795         }
 796
 797         if (change_irq)
 798                 port->irq      = new_serial.irq;
 799         if (!(port->flags & UPF_FIXED_PORT))
 800                 port->uartclk  = new_serial.baud_base * 16;
 801         port->flags            = (port->flags & ~UPF_CHANGE_MASK) |
 802                                  (new_flags & UPF_CHANGE_MASK);
 803         port->custom_divisor   = new_serial.custom_divisor;
 804         state->close_delay     = close_delay;
 805         state->closing_wait    = closing_wait;
 806         if (new_serial.xmit_fifo_size)
 807                 port->fifosize = new_serial.xmit_fifo_size;
 808         if (state->info->tty)
 809                 state->info->tty->low_latency =
 810                         (port->flags & UPF_LOW_LATENCY) ? 1 : 0;
 811
 812  check_and_exit:
 813         retval = 0;
 814         if (port->type == PORT_UNKNOWN)
 815                 goto exit;
 816         if (state->info->flags & UIF_INITIALIZED) {
 817                 if (((old_flags ^ port->flags) & UPF_SPD_MASK) ||
 818                     old_custom_divisor != port->custom_divisor) {
 819                         /*
 820                          * If they're setting up a custom divisor or speed,
 821                          * instead of clearing it, then bitch about it. No
 822                          * need to rate-limit; it's CAP_SYS_ADMIN only.
 823                          */
 824                         if (port->flags & UPF_SPD_MASK) {
 825                                 char buf[64];
 826                                 printk(KERN_NOTICE
 827                                        "%s sets custom speed on %s. This "
 828                                        "is deprecated.\n", current->comm,
 829                                        tty_name(state->info->tty, buf));
 830                         }
 831                         uart_change_speed(state, NULL);
 832                 }
 833         } else
 834                 retval = uart_startup(state, 1);
 835  exit:
 836         mutex_unlock(&state->mutex);
 837         return retval;
 838 }
 839
 840
 841 /*
 842  * uart_get_lsr_info - get line status register info.
 843  * Note: uart_ioctl protects us against hangups.
 844  */
 845 static int uart_get_lsr_info(struct uart_state *state,
 846                              unsigned int __user *value)
 847 {
 848         struct uart_port *port = state->port;
 849         unsigned int result;
 850
 851         result = port->ops->tx_empty(port);
 852
 853         /*
 854          * If we're about to load something into the transmit
 855          * register, we'll pretend the transmitter isn't empty to
 856          * avoid a race condition (depending on when the transmit
 857          * interrupt happens).
 858          */
 859         if (port->x_char ||
 860             ((uart_circ_chars_pending(&state->info->xmit) > 0) &&
 861              !state->info->tty->stopped && !state->info->tty->hw_stopped))
 862                 result &= ~TIOCSER_TEMT;
 863
 864         return put_user(result, value);
 865 }
 866
 867 static int uart_tiocmget(struct tty_struct *tty, struct file *file)
 868 {
 869         struct uart_state *state = tty->driver_data;
 870         struct uart_port *port = state->port;
 871         int result = -EIO;
 872
 873         mutex_lock(&state->mutex);
 874         if ((!file || !tty_hung_up_p(file)) &&
 875             !(tty->flags & (1 << TTY_IO_ERROR))) {
 876                 result = port->mctrl;
 877
 878                 spin_lock_irq(&port->lock);
 879                 result |= port->ops->get_mctrl(port);
 880                 spin_unlock_irq(&port->lock);
 881         }
 882         mutex_unlock(&state->mutex);
 883
 884         return result;
 885 }
 886
 887 static int
 888 uart_tiocmset(struct tty_struct *tty, struct file *file,
 889               unsigned int set, unsigned int clear)
 890 {
 891         struct uart_state *state = tty->driver_data;
 892         struct uart_port *port = state->port;
 893         int ret = -EIO;
 894
 895         mutex_lock(&state->mutex);
 896         if ((!file || !tty_hung_up_p(file)) &&
 897             !(tty->flags & (1 << TTY_IO_ERROR))) {
 898                 uart_update_mctrl(port, set, clear);
 899                 ret = 0;
 900         }
 901         mutex_unlock(&state->mutex);
 902         return ret;
 903 }
 904
 905 static void uart_break_ctl(struct tty_struct *tty, int break_state)
 906 {
 907         struct uart_state *state = tty->driver_data;
 908         struct uart_port *port = state->port;
 909
 910         BUG_ON(!kernel_locked());
 911
 912         mutex_lock(&state->mutex);
 913
 914         if (port->type != PORT_UNKNOWN)
 915                 port->ops->break_ctl(port, break_state);
 916
 917         mutex_unlock(&state->mutex);
 918 }
 919
 920 static int uart_do_autoconfig(struct uart_state *state)
 921 {
 922         struct uart_port *port = state->port;
 923         int flags, ret;
 924
 925         if (!capable(CAP_SYS_ADMIN))
 926                 return -EPERM;
 927
 928         /*
 929          * Take the per-port semaphore.  This prevents count from
 930          * changing, and hence any extra opens of the port while
 931          * we're auto-configuring.
 932          */
 933         if (mutex_lock_interruptible(&state->mutex))
 934                 return -ERESTARTSYS;
 935
 936         ret = -EBUSY;
 937         if (uart_users(state) == 1) {
 938                 uart_shutdown(state);
 939
 940                 /*
 941                  * If we already have a port type configured,
 942                  * we must release its resources.
 943                  */
 944                 if (port->type != PORT_UNKNOWN)
 945                         port->ops->release_port(port);
 946
 947                 flags = UART_CONFIG_TYPE;
 948                 if (port->flags & UPF_AUTO_IRQ)
 949                         flags |= UART_CONFIG_IRQ;
 950
 951                 /*
 952                  * This will claim the ports resources if
 953                  * a port is found.
 954                  */
 955                 port->ops->config_port(port, flags);
 956
 957                 ret = uart_startup(state, 1);
 958         }
 959         mutex_unlock(&state->mutex);
 960         return ret;
 961 }
 962
 963 /*
 964  * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
 965  * - mask passed in arg for lines of interest
 966  *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
 967  * Caller should use TIOCGICOUNT to see which one it was
 968  */
 969 static int
 970 uart_wait_modem_status(struct uart_state *state, unsigned long arg)
 971 {
 972         struct uart_port *port = state->port;
 973         DECLARE_WAITQUEUE(wait, current);
 974         struct uart_icount cprev, cnow;
 975         int ret;
 976
 977         /*
 978          * note the counters on entry
 979          */
 980         spin_lock_irq(&port->lock);
 981         memcpy(&cprev, &port->icount, sizeof(struct uart_icount));
 982
 983         /*
 984          * Force modem status interrupts on
 985          */
 986         port->ops->enable_ms(port);
 987         spin_unlock_irq(&port->lock);
 988
 989         add_wait_queue(&state->info->delta_msr_wait, &wait);
 990         for (;;) {
 991                 spin_lock_irq(&port->lock);
 992                 memcpy(&cnow, &port->icount, sizeof(struct uart_icount));
 993                 spin_unlock_irq(&port->lock);
 994
 995                 set_current_state(TASK_INTERRUPTIBLE);
 996
 997                 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
 998                     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
 999                     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
1000                     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1001                         ret = 0;
1002                         break;
1003                 }
1004
1005                 schedule();
1006
1007                 /* see if a signal did it */
1008                 if (signal_pending(current)) {
1009                         ret = -ERESTARTSYS;
1010                         break;
1011                 }
1012
1013                 cprev = cnow;
1014         }
1015
1016         current->state = TASK_RUNNING;
1017         remove_wait_queue(&state->info->delta_msr_wait, &wait);
1018
1019         return ret;
1020 }
1021
1022 /*
1023  * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1024  * Return: write counters to the user passed counter struct
1025  * NB: both 1->0 and 0->1 transitions are counted except for
1026  *     RI where only 0->1 is counted.
1027  */
1028 static int uart_get_count(struct uart_state *state,
1029                           struct serial_icounter_struct __user *icnt)
1030 {
1031         struct serial_icounter_struct icount;
1032         struct uart_icount cnow;
1033         struct uart_port *port = state->port;
1034
1035         spin_lock_irq(&port->lock);
1036         memcpy(&cnow, &port->icount, sizeof(struct uart_icount));
1037         spin_unlock_irq(&port->lock);
1038
1039         icount.cts         = cnow.cts;
1040         icount.dsr         = cnow.dsr;
1041         icount.rng         = cnow.rng;
1042         icount.dcd         = cnow.dcd;
1043         icount.rx          = cnow.rx;
1044         icount.tx          = cnow.tx;
1045         icount.frame       = cnow.frame;
1046         icount.overrun     = cnow.overrun;
1047         icount.parity      = cnow.parity;
1048         icount.brk         = cnow.brk;
1049         icount.buf_overrun = cnow.buf_overrun;
1050
1051         return copy_to_user(icnt, &icount, sizeof(icount)) ? -EFAULT : 0;
1052 }
1053
1054 /*
1055  * Called via sys_ioctl under the BKL.  We can use spin_lock_irq() here.
1056  */
1057 static int
1058 uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd,
1059            unsigned long arg)
1060 {
1061         struct uart_state *state = tty->driver_data;
1062         void __user *uarg = (void __user *)arg;
1063         int ret = -ENOIOCTLCMD;
1064
1065         BUG_ON(!kernel_locked());
1066
1067         /*
1068          * These ioctls don't rely on the hardware to be present.
1069          */
1070         switch (cmd) {
1071         case TIOCGSERIAL:
1072                 ret = uart_get_info(state, uarg);
1073                 break;
1074
1075         case TIOCSSERIAL:
1076                 ret = uart_set_info(state, uarg);
1077                 break;
1078
1079         case TIOCSERCONFIG:
1080                 ret = uart_do_autoconfig(state);
1081                 break;
1082
1083         case TIOCSERGWILD: /* obsolete */
1084         case TIOCSERSWILD: /* obsolete */
1085                 ret = 0;
1086                 break;
1087         }
1088
1089         if (ret != -ENOIOCTLCMD)
1090                 goto out;
1091
1092         if (tty->flags & (1 << TTY_IO_ERROR)) {
1093                 ret = -EIO;
1094                 goto out;
1095         }
1096
1097         /*
1098          * The following should only be used when hardware is present.
1099          */
1100         switch (cmd) {
1101         case TIOCMIWAIT:
1102                 ret = uart_wait_modem_status(state, arg);
1103                 break;
1104
1105         case TIOCGICOUNT:
1106                 ret = uart_get_count(state, uarg);
1107                 break;
1108         }
1109
1110         if (ret != -ENOIOCTLCMD)
1111                 goto out;
1112
1113         mutex_lock(&state->mutex);
1114
1115         if (tty_hung_up_p(filp)) {
1116                 ret = -EIO;
1117                 goto out_up;
1118         }
1119
1120         /*
1121          * All these rely on hardware being present and need to be
1122          * protected against the tty being hung up.
1123          */
1124         switch (cmd) {
1125         case TIOCSERGETLSR: /* Get line status register */
1126                 ret = uart_get_lsr_info(state, uarg);
1127                 break;
1128
1129         default: {
1130                 struct uart_port *port = state->port;
1131                 if (port->ops->ioctl)
1132                         ret = port->ops->ioctl(port, cmd, arg);
1133                 break;
1134         }
1135         }
1136  out_up:
1137         mutex_unlock(&state->mutex);
1138  out:
1139         return ret;
1140 }
1141
1142 static void uart_set_termios(struct tty_struct *tty,
1143                                                 struct ktermios *old_termios)
1144 {
1145         struct uart_state *state = tty->driver_data;
1146         unsigned long flags;
1147         unsigned int cflag = tty->termios->c_cflag;
1148
1149         BUG_ON(!kernel_locked());
1150
1151         /*
1152          * These are the bits that are used to setup various
1153          * flags in the low level driver. We can ignore the Bfoo
1154          * bits in c_cflag; c_[io]speed will always be set
1155          * appropriately by set_termios() in tty_ioctl.c
1156          */
1157 #define RELEVANT_IFLAG(iflag)   ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
1158         if ((cflag ^ old_termios->c_cflag) == 0 &&
1159             tty->termios->c_ospeed == old_termios->c_ospeed &&
1160             tty->termios->c_ispeed == old_termios->c_ispeed &&
1161             RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0)
1162                 return;
1163
1164         uart_change_speed(state, old_termios);
1165
1166         /* Handle transition to B0 status */
1167         if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1168                 uart_clear_mctrl(state->port, TIOCM_RTS | TIOCM_DTR);
1169
1170         /* Handle transition away from B0 status */
1171         if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1172                 unsigned int mask = TIOCM_DTR;
1173                 if (!(cflag & CRTSCTS) ||
1174                     !test_bit(TTY_THROTTLED, &tty->flags))
1175                         mask |= TIOCM_RTS;
1176                 uart_set_mctrl(state->port, mask);
1177         }
1178
1179         /* Handle turning off CRTSCTS */
1180         if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1181                 spin_lock_irqsave(&state->port->lock, flags);
1182                 tty->hw_stopped = 0;
1183                 __uart_start(tty);
1184                 spin_unlock_irqrestore(&state->port->lock, flags);
1185         }
1186
1187         /* Handle turning on CRTSCTS */
1188         if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1189                 spin_lock_irqsave(&state->port->lock, flags);
1190                 if (!(state->port->ops->get_mctrl(state->port) & TIOCM_CTS)) {
1191                         tty->hw_stopped = 1;
1192                         state->port->ops->stop_tx(state->port);
1193                 }
1194                 spin_unlock_irqrestore(&state->port->lock, flags);
1195         }
1196
1197 #if 0
1198         /*
1199          * No need to wake up processes in open wait, since they
1200          * sample the CLOCAL flag once, and don't recheck it.
1201          * XXX  It's not clear whether the current behavior is correct
1202          * or not.  Hence, this may change.....
1203          */
1204         if (!(old_termios->c_cflag & CLOCAL) &&
1205             (tty->termios->c_cflag & CLOCAL))
1206                 wake_up_interruptible(&state->info->open_wait);
1207 #endif
1208 }
1209
1210 /*
1211  * In 2.4.5, calls to this will be serialized via the BKL in
1212  *  linux/drivers/char/tty_io.c:tty_release()
1213  *  linux/drivers/char/tty_io.c:do_tty_handup()
1214  */
1215 static void uart_close(struct tty_struct *tty, struct file *filp)
1216 {
1217         struct uart_state *state = tty->driver_data;
1218         struct uart_port *port;
1219
1220         BUG_ON(!kernel_locked());
1221
1222         if (!state || !state->port)
1223                 return;
1224
1225         port = state->port;
1226
1227         pr_debug("uart_close(%d) called\n", port->line);
1228
1229         mutex_lock(&state->mutex);
1230
1231         if (tty_hung_up_p(filp))
1232                 goto done;
1233
1234         if ((tty->count == 1) && (state->count != 1)) {
1235                 /*
1236                  * Uh, oh.  tty->count is 1, which means that the tty
1237                  * structure will be freed.  state->count should always
1238                  * be one in these conditions.  If it's greater than
1239                  * one, we've got real problems, since it means the
1240                  * serial port won't be shutdown.
1241                  */
1242                 printk(KERN_ERR "uart_close: bad serial port count; tty->count is 1, "
1243                        "state->count is %d\n", state->count);
1244                 state->count = 1;
1245         }
1246         if (--state->count < 0) {
1247                 printk(KERN_ERR "uart_close: bad serial port count for %s: %d\n",
1248                        tty->name, state->count);
1249                 state->count = 0;
1250         }
1251         if (state->count)
1252                 goto done;
1253
1254         /*
1255          * Now we wait for the transmit buffer to clear; and we notify
1256          * the line discipline to only process XON/XOFF characters by
1257          * setting tty->closing.
1258          */
1259         tty->closing = 1;
1260
1261         if (state->closing_wait != USF_CLOSING_WAIT_NONE)
1262                 tty_wait_until_sent(tty, msecs_to_jiffies(state->closing_wait));
1263
1264         /*
1265          * At this point, we stop accepting input.  To do this, we
1266          * disable the receive line status interrupts.
1267          */
1268         if (state->info->flags & UIF_INITIALIZED) {
1269                 unsigned long flags;
1270                 spin_lock_irqsave(&port->lock, flags);
1271                 port->ops->stop_rx(port);
1272                 spin_unlock_irqrestore(&port->lock, flags);
1273                 /*
1274                  * Before we drop DTR, make sure the UART transmitter
1275                  * has completely drained; this is especially
1276                  * important if there is a transmit FIFO!
1277                  */
1278                 uart_wait_until_sent(tty, port->timeout);
1279         }
1280
1281         uart_shutdown(state);
1282         uart_flush_buffer(tty);
1283
1284         tty_ldisc_flush(tty);
1285
1286         tty->closing = 0;
1287         state->info->tty = NULL;
1288
1289         if (state->info->blocked_open) {
1290                 if (state->close_delay)
1291                         msleep_interruptible(state->close_delay);
1292         } else if (!uart_console(port)) {
1293                 uart_change_pm(state, 3);
1294         }
1295
1296         /*
1297          * Wake up anyone trying to open this port.
1298          */
1299         state->info->flags &= ~UIF_NORMAL_ACTIVE;
1300         wake_up_interruptible(&state->info->open_wait);
1301
1302  done:
1303         mutex_unlock(&state->mutex);
1304 }
1305
1306 static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1307 {
1308         struct uart_state *state = tty->driver_data;
1309         struct uart_port *port = state->port;
1310         unsigned long char_time, expire;
1311
1312         BUG_ON(!kernel_locked());
1313
1314         if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1315                 return;
1316
1317         /*
1318          * Set the check interval to be 1/5 of the estimated time to
1319          * send a single character, and make it at least 1.  The check
1320          * interval should also be less than the timeout.
1321          *
1322          * Note: we have to use pretty tight timings here to satisfy
1323          * the NIST-PCTS.
1324          */
1325         char_time = (port->timeout - HZ/50) / port->fifosize;
1326         char_time = char_time / 5;
1327         if (char_time == 0)
1328                 char_time = 1;
1329         if (timeout && timeout < char_time)
1330                 char_time = timeout;
1331
1332         /*
1333          * If the transmitter hasn't cleared in twice the approximate
1334          * amount of time to send the entire FIFO, it probably won't
1335          * ever clear.  This assumes the UART isn't doing flow
1336          * control, which is currently the case.  Hence, if it ever
1337          * takes longer than port->timeout, this is probably due to a
1338          * UART bug of some kind.  So, we clamp the timeout parameter at
1339          * 2*port->timeout.
1340          */
1341         if (timeout == 0 || timeout > 2 * port->timeout)
1342                 timeout = 2 * port->timeout;
1343
1344         expire = jiffies + timeout;
1345
1346         pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1347                 port->line, jiffies, expire);
1348
1349         /*
1350          * Check whether the transmitter is empty every 'char_time'.
1351          * 'timeout' / 'expire' give us the maximum amount of time
1352          * we wait.
1353          */
1354         while (!port->ops->tx_empty(port)) {
1355                 msleep_interruptible(jiffies_to_msecs(char_time));
1356                 if (signal_pending(current))
1357                         break;
1358                 if (time_after(jiffies, expire))
1359                         break;
1360         }
1361         set_current_state(TASK_RUNNING); /* might not be needed */
1362 }
1363
1364 /*
1365  * This is called with the BKL held in
1366  *  linux/drivers/char/tty_io.c:do_tty_hangup()
1367  * We're called from the eventd thread, so we can sleep for
1368  * a _short_ time only.
1369  */
1370 static void uart_hangup(struct tty_struct *tty)
1371 {
1372         struct uart_state *state = tty->driver_data;
1373
1374         BUG_ON(!kernel_locked());
1375         pr_debug("uart_hangup(%d)\n", state->port->line);
1376
1377         mutex_lock(&state->mutex);
1378         if (state->info && state->info->flags & UIF_NORMAL_ACTIVE) {
1379                 uart_flush_buffer(tty);
1380                 uart_shutdown(state);
1381                 state->count = 0;
1382                 state->info->flags &= ~UIF_NORMAL_ACTIVE;
1383                 state->info->tty = NULL;
1384                 wake_up_interruptible(&state->info->open_wait);
1385                 wake_up_interruptible(&state->info->delta_msr_wait);
1386         }
1387         mutex_unlock(&state->mutex);
1388 }
1389
1390 /*
1391  * Copy across the serial console cflag setting into the termios settings
1392  * for the initial open of the port.  This allows continuity between the
1393  * kernel settings, and the settings init adopts when it opens the port
1394  * for the first time.
1395  */
1396 static void uart_update_termios(struct uart_state *state)
1397 {
1398         struct tty_struct *tty = state->info->tty;
1399         struct uart_port *port = state->port;
1400
1401         if (uart_console(port) && port->cons->cflag) {
1402                 tty->termios->c_cflag = port->cons->cflag;
1403                 port->cons->cflag = 0;
1404         }
1405
1406         /*
1407          * If the device failed to grab its irq resources,
1408          * or some other error occurred, don't try to talk
1409          * to the port hardware.
1410          */
1411         if (!(tty->flags & (1 << TTY_IO_ERROR))) {
1412                 /*
1413                  * Make termios settings take effect.
1414                  */
1415                 uart_change_speed(state, NULL);
1416
1417                 /*
1418                  * And finally enable the RTS and DTR signals.
1419                  */
1420                 if (tty->termios->c_cflag & CBAUD)
1421                         uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
1422         }
1423 }
1424
1425 /*
1426  * Block the open until the port is ready.  We must be called with
1427  * the per-port semaphore held.
1428  */
1429 static int
1430 uart_block_til_ready(struct file *filp, struct uart_state *state)
1431 {
1432         DECLARE_WAITQUEUE(wait, current);
1433         struct uart_info *info = state->info;
1434         struct uart_port *port = state->port;
1435         unsigned int mctrl;
1436
1437         info->blocked_open++;
1438         state->count--;
1439
1440         add_wait_queue(&info->open_wait, &wait);
1441         while (1) {
1442                 set_current_state(TASK_INTERRUPTIBLE);
1443
1444                 /*
1445                  * If we have been hung up, tell userspace/restart open.
1446                  */
1447                 if (tty_hung_up_p(filp) || info->tty == NULL)
1448                         break;
1449
1450                 /*
1451                  * If the port has been closed, tell userspace/restart open.
1452                  */
1453                 if (!(info->flags & UIF_INITIALIZED))
1454                         break;
1455
1456                 /*
1457                  * If non-blocking mode is set, or CLOCAL mode is set,
1458                  * we don't want to wait for the modem status lines to
1459                  * indicate that the port is ready.
1460                  *
1461                  * Also, if the port is not enabled/configured, we want
1462                  * to allow the open to succeed here.  Note that we will
1463                  * have set TTY_IO_ERROR for a non-existant port.
1464                  */
1465                 if ((filp->f_flags & O_NONBLOCK) ||
1466                     (info->tty->termios->c_cflag & CLOCAL) ||
1467                     (info->tty->flags & (1 << TTY_IO_ERROR)))
1468                         break;
1469
1470                 /*
1471                  * Set DTR to allow modem to know we're waiting.  Do
1472                  * not set RTS here - we want to make sure we catch
1473                  * the data from the modem.
1474                  */
1475                 if (info->tty->termios->c_cflag & CBAUD)
1476                         uart_set_mctrl(port, TIOCM_DTR);
1477
1478                 /*
1479                  * and wait for the carrier to indicate that the
1480                  * modem is ready for us.
1481                  */
1482                 spin_lock_irq(&port->lock);
1483                 port->ops->enable_ms(port);
1484                 mctrl = port->ops->get_mctrl(port);
1485                 spin_unlock_irq(&port->lock);
1486                 if (mctrl & TIOCM_CAR)
1487                         break;
1488
1489                 mutex_unlock(&state->mutex);
1490                 schedule();
1491                 mutex_lock(&state->mutex);
1492
1493                 if (signal_pending(current))
1494                         break;
1495         }
1496         set_current_state(TASK_RUNNING);
1497         remove_wait_queue(&info->open_wait, &wait);
1498
1499         state->count++;
1500         info->blocked_open--;
1501
1502         if (signal_pending(current))
1503                 return -ERESTARTSYS;
1504
1505         if (!info->tty || tty_hung_up_p(filp))
1506                 return -EAGAIN;
1507
1508         return 0;
1509 }
1510
1511 static struct uart_state *uart_get(struct uart_driver *drv, int line)
1512 {
1513         struct uart_state *state;
1514         int ret = 0;
1515
1516         state = drv->state + line;
1517         if (mutex_lock_interruptible(&state->mutex)) {
1518                 ret = -ERESTARTSYS;
1519                 goto err;
1520         }
1521
1522         state->count++;
1523         if (!state->port || state->port->flags & UPF_DEAD) {
1524                 ret = -ENXIO;
1525                 goto err_unlock;
1526         }
1527
1528         if (!state->info) {
1529                 state->info = kzalloc(sizeof(struct uart_info), GFP_KERNEL);
1530                 if (state->info) {
1531                         init_waitqueue_head(&state->info->open_wait);
1532                         init_waitqueue_head(&state->info->delta_msr_wait);
1533
1534                         /*
1535                          * Link the info into the other structures.
1536                          */
1537                         state->port->info = state->info;
1538
1539                         tasklet_init(&state->info->tlet, uart_tasklet_action,
1540                                      (unsigned long)state);
1541                 } else {
1542                         ret = -ENOMEM;
1543                         goto err_unlock;
1544                 }
1545         }
1546         return state;
1547
1548  err_unlock:
1549         state->count--;
1550         mutex_unlock(&state->mutex);
1551  err:
1552         return ERR_PTR(ret);
1553 }
1554
1555 /*
1556  * In 2.4.5, calls to uart_open are serialised by the BKL in
1557  *   linux/fs/devices.c:chrdev_open()
1558  * Note that if this fails, then uart_close() _will_ be called.
1559  *
1560  * In time, we want to scrap the "opening nonpresent ports"
1561  * behaviour and implement an alternative way for setserial
1562  * to set base addresses/ports/types.  This will allow us to
1563  * get rid of a certain amount of extra tests.
1564  */
1565 static int uart_open(struct tty_struct *tty, struct file *filp)
1566 {
1567         struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state;
1568         struct uart_state *state;
1569         int retval, line = tty->index;
1570
1571         BUG_ON(!kernel_locked());
1572         pr_debug("uart_open(%d) called\n", line);
1573
1574         /*
1575          * tty->driver->num won't change, so we won't fail here with
1576          * tty->driver_data set to something non-NULL (and therefore
1577          * we won't get caught by uart_close()).
1578          */
1579         retval = -ENODEV;
1580         if (line >= tty->driver->num)
1581                 goto fail;
1582
1583         /*
1584          * We take the semaphore inside uart_get to guarantee that we won't
1585          * be re-entered while allocating the info structure, or while we
1586          * request any IRQs that the driver may need.  This also has the nice
1587          * side-effect that it delays the action of uart_hangup, so we can
1588          * guarantee that info->tty will always contain something reasonable.
1589          */
1590         state = uart_get(drv, line);
1591         if (IS_ERR(state)) {
1592                 retval = PTR_ERR(state);
1593                 goto fail;
1594         }
1595
1596         /*
1597          * Once we set tty->driver_data here, we are guaranteed that
1598          * uart_close() will decrement the driver module use count.
1599          * Any failures from here onwards should not touch the count.
1600          */
1601         tty->driver_data = state;
1602         tty->low_latency = (state->port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1603         tty->alt_speed = 0;
1604         state->info->tty = tty;
1605
1606         /*
1607          * If the port is in the middle of closing, bail out now.
1608          */
1609         if (tty_hung_up_p(filp)) {
1610                 retval = -EAGAIN;
1611                 state->count--;
1612                 mutex_unlock(&state->mutex);
1613                 goto fail;
1614         }
1615
1616         /*
1617          * Make sure the device is in D0 state.
1618          */
1619         if (state->count == 1)
1620                 uart_change_pm(state, 0);
1621
1622         /*
1623          * Start up the serial port.
1624          */
1625         retval = uart_startup(state, 0);
1626
1627         /*
1628          * If we succeeded, wait until the port is ready.
1629          */
1630         if (retval == 0)
1631                 retval = uart_block_til_ready(filp, state);
1632         mutex_unlock(&state->mutex);
1633
1634         /*
1635          * If this is the first open to succeed, adjust things to suit.
1636          */
1637         if (retval == 0 && !(state->info->flags & UIF_NORMAL_ACTIVE)) {
1638                 state->info->flags |= UIF_NORMAL_ACTIVE;
1639
1640                 uart_update_termios(state);
1641         }
1642
1643  fail:
1644         return retval;
1645 }
1646
1647 static const char *uart_type(struct uart_port *port)
1648 {
1649         const char *str = NULL;
1650
1651         if (port->ops->type)
1652                 str = port->ops->type(port);
1653
1654         if (!str)
1655                 str = "unknown";
1656
1657         return str;
1658 }
1659
1660 #ifdef CONFIG_PROC_FS
1661
1662 static int uart_line_info(char *buf, struct uart_driver *drv, int i)
1663 {
1664         struct uart_state *state = drv->state + i;
1665         int pm_state;
1666         struct uart_port *port = state->port;
1667         char stat_buf[32];
1668         unsigned int status;
1669         int mmio, ret;
1670
1671         if (!port)
1672                 return 0;
1673
1674         mmio = port->iotype >= UPIO_MEM;
1675         ret = sprintf(buf, "%d: uart:%s %s%08llX irq:%d",
1676                         port->line, uart_type(port),
1677                         mmio ? "mmio:0x" : "port:",
1678                         mmio ? (unsigned long long)port->mapbase
1679                              : (unsigned long long) port->iobase,
1680                         port->irq);
1681
1682         if (port->type == PORT_UNKNOWN) {
1683                 strcat(buf, "\n");
1684                 return ret + 1;
1685         }
1686
1687         if (capable(CAP_SYS_ADMIN)) {
1688                 mutex_lock(&state->mutex);
1689                 pm_state = state->pm_state;
1690                 if (pm_state)
1691                         uart_change_pm(state, 0);
1692                 spin_lock_irq(&port->lock);
1693                 status = port->ops->get_mctrl(port);
1694                 spin_unlock_irq(&port->lock);
1695                 if (pm_state)
1696                         uart_change_pm(state, pm_state);
1697                 mutex_unlock(&state->mutex);
1698
1699                 ret += sprintf(buf + ret, " tx:%d rx:%d",
1700                                 port->icount.tx, port->icount.rx);
1701                 if (port->icount.frame)
1702                         ret += sprintf(buf + ret, " fe:%d",
1703                                 port->icount.frame);
1704                 if (port->icount.parity)
1705                         ret += sprintf(buf + ret, " pe:%d",
1706                                 port->icount.parity);
1707                 if (port->icount.brk)
1708                         ret += sprintf(buf + ret, " brk:%d",
1709                                 port->icount.brk);
1710                 if (port->icount.overrun)
1711                         ret += sprintf(buf + ret, " oe:%d",
1712                                 port->icount.overrun);
1713
1714 #define INFOBIT(bit, str) \
1715         if (port->mctrl & (bit)) \
1716                 strncat(stat_buf, (str), sizeof(stat_buf) - \
1717                         strlen(stat_buf) - 2)
1718 #define STATBIT(bit, str) \
1719         if (status & (bit)) \
1720                 strncat(stat_buf, (str), sizeof(stat_buf) - \
1721                        strlen(stat_buf) - 2)
1722
1723                 stat_buf[0] = '\0';
1724                 stat_buf[1] = '\0';
1725                 INFOBIT(TIOCM_RTS, "|RTS");
1726                 STATBIT(TIOCM_CTS, "|CTS");
1727                 INFOBIT(TIOCM_DTR, "|DTR");
1728                 STATBIT(TIOCM_DSR, "|DSR");
1729                 STATBIT(TIOCM_CAR, "|CD");
1730                 STATBIT(TIOCM_RNG, "|RI");
1731                 if (stat_buf[0])
1732                         stat_buf[0] = ' ';
1733                 strcat(stat_buf, "\n");
1734
1735                 ret += sprintf(buf + ret, stat_buf);
1736         } else {
1737                 strcat(buf, "\n");
1738                 ret++;
1739         }
1740 #undef STATBIT
1741 #undef INFOBIT
1742         return ret;
1743 }
1744
1745 static int uart_read_proc(char *page, char **start, off_t off,
1746                           int count, int *eof, void *data)
1747 {
1748         struct tty_driver *ttydrv = data;
1749         struct uart_driver *drv = ttydrv->driver_state;
1750         int i, len = 0, l;
1751         off_t begin = 0;
1752
1753         len += sprintf(page, "serinfo:1.0 driver%s%s revision:%s\n",
1754                         "", "", "");
1755         for (i = 0; i < drv->nr && len < PAGE_SIZE - 96; i++) {
1756                 l = uart_line_info(page + len, drv, i);
1757                 len += l;
1758                 if (len + begin > off + count)
1759                         goto done;
1760                 if (len + begin < off) {
1761                         begin += len;
1762                         len = 0;
1763                 }
1764         }
1765         *eof = 1;
1766  done:
1767         if (off >= len + begin)
1768                 return 0;
1769         *start = page + (off - begin);
1770         return (count < begin + len - off) ? count : (begin + len - off);
1771 }
1772 #endif
1773
1774 #ifdef CONFIG_SERIAL_CORE_CONSOLE
1775 /*
1776  *      uart_console_write - write a console message to a serial port
1777  *      @port: the port to write the message
1778  *      @s: array of characters
1779  *      @count: number of characters in string to write
1780  *      @write: function to write character to port
1781  */
1782 void uart_console_write(struct uart_port *port, const char *s,
1783                         unsigned int count,
1784                         void (*putchar)(struct uart_port *, int))
1785 {
1786         unsigned int i;
1787
1788         for (i = 0; i < count; i++, s++) {
1789                 if (*s == '\n')
1790                         putchar(port, '\r');
1791                 putchar(port, *s);
1792         }
1793 }
1794 EXPORT_SYMBOL_GPL(uart_console_write);
1795
1796 /*
1797  *      Check whether an invalid uart number has been specified, and
1798  *      if so, search for the first available port that does have
1799  *      console support.
1800  */
1801 struct uart_port * __init
1802 uart_get_console(struct uart_port *ports, int nr, struct console *co)
1803 {
1804         int idx = co->index;
1805
1806         if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1807                                      ports[idx].membase == NULL))
1808                 for (idx = 0; idx < nr; idx++)
1809                         if (ports[idx].iobase != 0 ||
1810                             ports[idx].membase != NULL)
1811                                 break;
1812
1813         co->index = idx;
1814
1815         return ports + idx;
1816 }
1817
1818 /**
1819  *      uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1820  *      @options: pointer to option string
1821  *      @baud: pointer to an 'int' variable for the baud rate.
1822  *      @parity: pointer to an 'int' variable for the parity.
1823  *      @bits: pointer to an 'int' variable for the number of data bits.
1824  *      @flow: pointer to an 'int' variable for the flow control character.
1825  *
1826  *      uart_parse_options decodes a string containing the serial console
1827  *      options.  The format of the string is <baud><parity><bits><flow>,
1828  *      eg: 115200n8r
1829  */
1830 void __init
1831 uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1832 {
1833         char *s = options;
1834
1835         *baud = simple_strtoul(s, NULL, 10);
1836         while (*s >= '0' && *s <= '9')
1837                 s++;
1838         if (*s)
1839                 *parity = *s++;
1840         if (*s)
1841                 *bits = *s++ - '0';
1842         if (*s)
1843                 *flow = *s;
1844 }
1845
1846 struct baud_rates {
1847         unsigned int rate;
1848         unsigned int cflag;
1849 };
1850
1851 static const struct baud_rates baud_rates[] = {
1852         { 921600, B921600 },
1853         { 460800, B460800 },
1854         { 230400, B230400 },
1855         { 115200, B115200 },
1856         {  57600, B57600  },
1857         {  38400, B38400  },
1858         {  19200, B19200  },
1859         {   9600, B9600   },
1860         {   4800, B4800   },
1861         {   2400, B2400   },
1862         {   1200, B1200   },
1863         {      0, B38400  }
1864 };
1865
1866 /**
1867  *      uart_set_options - setup the serial console parameters
1868  *      @port: pointer to the serial ports uart_port structure
1869  *      @co: console pointer
1870  *      @baud: baud rate
1871  *      @parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1872  *      @bits: number of data bits
1873  *      @flow: flow control character - 'r' (rts)
1874  */
1875 int __init
1876 uart_set_options(struct uart_port *port, struct console *co,
1877                  int baud, int parity, int bits, int flow)
1878 {
1879         struct ktermios termios;
1880         static struct ktermios dummy;
1881         int i;
1882
1883         /*
1884          * Ensure that the serial console lock is initialised
1885          * early.
1886          */
1887         spin_lock_init(&port->lock);
1888         lockdep_set_class(&port->lock, &port_lock_key);
1889
1890         memset(&termios, 0, sizeof(struct ktermios));
1891
1892         termios.c_cflag = CREAD | HUPCL | CLOCAL;
1893
1894         /*
1895          * Construct a cflag setting.
1896          */
1897         for (i = 0; baud_rates[i].rate; i++)
1898                 if (baud_rates[i].rate <= baud)
1899                         break;
1900
1901         termios.c_cflag |= baud_rates[i].cflag;
1902
1903         if (bits == 7)
1904                 termios.c_cflag |= CS7;
1905         else
1906                 termios.c_cflag |= CS8;
1907
1908         switch (parity) {
1909         case 'o': case 'O':
1910                 termios.c_cflag |= PARODD;
1911                 /*fall through*/
1912         case 'e': case 'E':
1913                 termios.c_cflag |= PARENB;
1914                 break;
1915         }
1916
1917         if (flow == 'r')
1918                 termios.c_cflag |= CRTSCTS;
1919
1920         /*
1921          * some uarts on other side don't support no flow control.
1922          * So we set * DTR in host uart to make them happy
1923          */
1924         port->mctrl |= TIOCM_DTR;
1925
1926         port->ops->set_termios(port, &termios, &dummy);
1927         co->cflag = termios.c_cflag;
1928
1929         return 0;
1930 }
1931 #endif /* CONFIG_SERIAL_CORE_CONSOLE */
1932
1933 static void uart_change_pm(struct uart_state *state, int pm_state)
1934 {
1935         struct uart_port *port = state->port;
1936
1937         if (state->pm_state != pm_state) {
1938                 if (port->ops->pm)
1939                         port->ops->pm(port, pm_state, state->pm_state);
1940                 state->pm_state = pm_state;
1941         }
1942 }
1943
1944 struct uart_match {
1945         struct uart_port *port;
1946         struct uart_driver *driver;
1947 };
1948
1949 static int serial_match_port(struct device *dev, void *data)
1950 {
1951         struct uart_match *match = data;
1952         dev_t devt = MKDEV(match->driver->major, match->driver->minor) + match->port->line;
1953
1954         return dev->devt == devt; /* Actually, only one tty per port */
1955 }
1956
1957 int uart_suspend_port(struct uart_driver *drv, struct uart_port *port)
1958 {
1959         struct uart_state *state = drv->state + port->line;
1960         struct device *tty_dev;
1961         struct uart_match match = {port, drv};
1962
1963         mutex_lock(&state->mutex);
1964
1965         if (!console_suspend_enabled && uart_console(port)) {
1966                 /* we're going to avoid suspending serial console */
1967                 mutex_unlock(&state->mutex);
1968                 return 0;
1969         }
1970
1971         tty_dev = device_find_child(port->dev, &match, serial_match_port);
1972         if (device_may_wakeup(tty_dev)) {
1973                 enable_irq_wake(port->irq);
1974                 put_device(tty_dev);
1975                 mutex_unlock(&state->mutex);
1976                 return 0;
1977         }
1978         port->suspended = 1;
1979
1980         if (state->info && state->info->flags & UIF_INITIALIZED) {
1981                 const struct uart_ops *ops = port->ops;
1982                 int tries;
1983
1984                 state->info->flags = (state->info->flags & ~UIF_INITIALIZED)
1985                                      | UIF_SUSPENDED;
1986
1987                 spin_lock_irq(&port->lock);
1988                 ops->stop_tx(port);
1989                 ops->set_mctrl(port, 0);
1990                 ops->stop_rx(port);
1991                 spin_unlock_irq(&port->lock);
1992
1993                 /*
1994                  * Wait for the transmitter to empty.
1995                  */
1996                 for (tries = 3; !ops->tx_empty(port) && tries; tries--)
1997                         msleep(10);
1998                 if (!tries)
1999                         printk(KERN_ERR "%s%s%s%d: Unable to drain "
2000                                         "transmitter\n",
2001                                port->dev ? port->dev->bus_id : "",
2002                                port->dev ? ": " : "",
2003                                drv->dev_name, port->line);
2004
2005                 ops->shutdown(port);
2006         }
2007
2008         /*
2009          * Disable the console device before suspending.
2010          */
2011         if (uart_console(port))
2012                 console_stop(port->cons);
2013
2014         uart_change_pm(state, 3);
2015
2016         mutex_unlock(&state->mutex);
2017
2018         return 0;
2019 }
2020
2021 int uart_resume_port(struct uart_driver *drv, struct uart_port *port)
2022 {
2023         struct uart_state *state = drv->state + port->line;
2024
2025         mutex_lock(&state->mutex);
2026
2027         if (!console_suspend_enabled && uart_console(port)) {
2028                 /* no need to resume serial console, it wasn't suspended */
2029                 mutex_unlock(&state->mutex);
2030                 return 0;
2031         }
2032
2033         if (!port->suspended) {
2034                 disable_irq_wake(port->irq);
2035                 mutex_unlock(&state->mutex);
2036                 return 0;
2037         }
2038         port->suspended = 0;
2039
2040         /*
2041          * Re-enable the console device after suspending.
2042          */
2043         if (uart_console(port)) {
2044                 struct ktermios termios;
2045
2046                 /*
2047                  * First try to use the console cflag setting.
2048                  */
2049                 memset(&termios, 0, sizeof(struct ktermios));
2050                 termios.c_cflag = port->cons->cflag;
2051
2052                 /*
2053                  * If that's unset, use the tty termios setting.
2054                  */
2055                 if (state->info && state->info->tty && termios.c_cflag == 0)
2056                         termios = *state->info->tty->termios;
2057
2058                 uart_change_pm(state, 0);
2059                 port->ops->set_termios(port, &termios, NULL);
2060                 console_start(port->cons);
2061         }
2062
2063         if (state->info && state->info->flags & UIF_SUSPENDED) {
2064                 const struct uart_ops *ops = port->ops;
2065                 int ret;
2066
2067                 uart_change_pm(state, 0);
2068                 ops->set_mctrl(port, 0);
2069                 ret = ops->startup(port);
2070                 if (ret == 0) {
2071                         uart_change_speed(state, NULL);
2072                         spin_lock_irq(&port->lock);
2073                         ops->set_mctrl(port, port->mctrl);
2074                         ops->start_tx(port);
2075                         spin_unlock_irq(&port->lock);
2076                         state->info->flags |= UIF_INITIALIZED;
2077                 } else {
2078                         /*
2079                          * Failed to resume - maybe hardware went away?
2080                          * Clear the "initialized" flag so we won't try
2081                          * to call the low level drivers shutdown method.
2082                          */
2083                         uart_shutdown(state);
2084                 }
2085
2086                 state->info->flags &= ~UIF_SUSPENDED;
2087         }
2088
2089         mutex_unlock(&state->mutex);
2090
2091         return 0;
2092 }
2093
2094 static inline void
2095 uart_report_port(struct uart_driver *drv, struct uart_port *port)
2096 {
2097         char address[64];
2098
2099         switch (port->iotype) {
2100         case UPIO_PORT:
2101                 snprintf(address, sizeof(address),
2102                          "I/O 0x%x", port->iobase);
2103                 break;
2104         case UPIO_HUB6:
2105                 snprintf(address, sizeof(address),
2106                          "I/O 0x%x offset 0x%x", port->iobase, port->hub6);
2107                 break;
2108         case UPIO_MEM:
2109         case UPIO_MEM32:
2110         case UPIO_AU:
2111         case UPIO_TSI:
2112         case UPIO_DWAPB:
2113                 snprintf(address, sizeof(address),
2114                          "MMIO 0x%llx", (unsigned long long)port->mapbase);
2115                 break;
2116         default:
2117                 strlcpy(address, "*unknown*", sizeof(address));
2118                 break;
2119         }
2120
2121         printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2122                port->dev ? port->dev->bus_id : "",
2123                port->dev ? ": " : "",
2124                drv->dev_name, port->line, address, port->irq, uart_type(port));
2125 }
2126
2127 static void
2128 uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2129                     struct uart_port *port)
2130 {
2131         unsigned int flags;
2132
2133         /*
2134          * If there isn't a port here, don't do anything further.
2135          */
2136         if (!port->iobase && !port->mapbase && !port->membase)
2137                 return;
2138
2139         /*
2140          * Now do the auto configuration stuff.  Note that config_port
2141          * is expected to claim the resources and map the port for us.
2142          */
2143         flags = UART_CONFIG_TYPE;
2144         if (port->flags & UPF_AUTO_IRQ)
2145                 flags |= UART_CONFIG_IRQ;
2146         if (port->flags & UPF_BOOT_AUTOCONF) {
2147                 port->type = PORT_UNKNOWN;
2148                 port->ops->config_port(port, flags);
2149         }
2150
2151         if (port->type != PORT_UNKNOWN) {
2152                 unsigned long flags;
2153
2154                 uart_report_port(drv, port);
2155
2156                 /* Power up port for set_mctrl() */
2157                 uart_change_pm(state, 0);
2158
2159                 /*
2160                  * Ensure that the modem control lines are de-activated.
2161                  * keep the DTR setting that is set in uart_set_options()
2162                  * We probably don't need a spinlock around this, but
2163                  */
2164                 spin_lock_irqsave(&port->lock, flags);
2165                 port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2166                 spin_unlock_irqrestore(&port->lock, flags);
2167
2168                 /*
2169                  * If this driver supports console, and it hasn't been
2170                  * successfully registered yet, try to re-register it.
2171                  * It may be that the port was not available.
2172                  */
2173                 if (port->cons && !(port->cons->flags & CON_ENABLED))
2174                         register_console(port->cons);
2175
2176                 /*
2177                  * Power down all ports by default, except the
2178                  * console if we have one.
2179                  */
2180                 if (!uart_console(port))
2181                         uart_change_pm(state, 3);
2182         }
2183 }
2184
2185 static const struct tty_operations uart_ops = {
2186         .open           = uart_open,
2187         .close          = uart_close,
2188         .write          = uart_write,
2189         .put_char       = uart_put_char,
2190         .flush_chars    = uart_flush_chars,
2191         .write_room     = uart_write_room,
2192         .chars_in_buffer= uart_chars_in_buffer,
2193         .flush_buffer   = uart_flush_buffer,
2194         .ioctl          = uart_ioctl,
2195         .throttle       = uart_throttle,
2196         .unthrottle     = uart_unthrottle,
2197         .send_xchar     = uart_send_xchar,
2198         .set_termios    = uart_set_termios,
2199         .stop           = uart_stop,
2200         .start          = uart_start,
2201         .hangup         = uart_hangup,
2202         .break_ctl      = uart_break_ctl,
2203         .wait_until_sent= uart_wait_until_sent,
2204 #ifdef CONFIG_PROC_FS
2205         .read_proc      = uart_read_proc,
2206 #endif
2207         .tiocmget       = uart_tiocmget,
2208         .tiocmset       = uart_tiocmset,
2209 };
2210
2211 /**
2212  *      uart_register_driver - register a driver with the uart core layer
2213  *      @drv: low level driver structure
2214  *
2215  *      Register a uart driver with the core driver.  We in turn register
2216  *      with the tty layer, and initialise the core driver per-port state.
2217  *
2218  *      We have a proc file in /proc/tty/driver which is named after the
2219  *      normal driver.
2220  *
2221  *      drv->port should be NULL, and the per-port structures should be
2222  *      registered using uart_add_one_port after this call has succeeded.
2223  */
2224 int uart_register_driver(struct uart_driver *drv)
2225 {
2226         struct tty_driver *normal = NULL;
2227         int i, retval;
2228
2229         BUG_ON(drv->state);
2230
2231         /*
2232          * Maybe we should be using a slab cache for this, especially if
2233          * we have a large number of ports to handle.
2234          */
2235         drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2236         retval = -ENOMEM;
2237         if (!drv->state)
2238                 goto out;
2239
2240         normal  = alloc_tty_driver(drv->nr);
2241         if (!normal)
2242                 goto out;
2243
2244         drv->tty_driver = normal;
2245
2246         normal->owner           = drv->owner;
2247         normal->driver_name     = drv->driver_name;
2248         normal->name            = drv->dev_name;
2249         normal->major           = drv->major;
2250         normal->minor_start     = drv->minor;
2251         normal->type            = TTY_DRIVER_TYPE_SERIAL;
2252         normal->subtype         = SERIAL_TYPE_NORMAL;
2253         normal->init_termios    = tty_std_termios;
2254         normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2255         normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2256         normal->flags           = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2257         normal->driver_state    = drv;
2258         tty_set_operations(normal, &uart_ops);
2259
2260         /*
2261          * Initialise the UART state(s).
2262          */
2263         for (i = 0; i < drv->nr; i++) {
2264                 struct uart_state *state = drv->state + i;
2265
2266                 state->close_delay     = 500;   /* .5 seconds */
2267                 state->closing_wait    = 30000; /* 30 seconds */
2268
2269                 mutex_init(&state->mutex);
2270         }
2271
2272         retval = tty_register_driver(normal);
2273  out:
2274         if (retval < 0) {
2275                 put_tty_driver(normal);
2276                 kfree(drv->state);
2277         }
2278         return retval;
2279 }
2280
2281 /**
2282  *      uart_unregister_driver - remove a driver from the uart core layer
2283  *      @drv: low level driver structure
2284  *
2285  *      Remove all references to a driver from the core driver.  The low
2286  *      level driver must have removed all its ports via the
2287  *      uart_remove_one_port() if it registered them with uart_add_one_port().
2288  *      (ie, drv->port == NULL)
2289  */
2290 void uart_unregister_driver(struct uart_driver *drv)
2291 {
2292         struct tty_driver *p = drv->tty_driver;
2293         tty_unregister_driver(p);
2294         put_tty_driver(p);
2295         kfree(drv->state);
2296         drv->tty_driver = NULL;
2297 }
2298
2299 struct tty_driver *uart_console_device(struct console *co, int *index)
2300 {
2301         struct uart_driver *p = co->data;
2302         *index = co->index;
2303         return p->tty_driver;
2304 }
2305
2306 /**
2307  *      uart_add_one_port - attach a driver-defined port structure
2308  *      @drv: pointer to the uart low level driver structure for this port
2309  *      @port: uart port structure to use for this port.
2310  *
2311  *      This allows the driver to register its own uart_port structure
2312  *      with the core driver.  The main purpose is to allow the low
2313  *      level uart drivers to expand uart_port, rather than having yet
2314  *      more levels of structures.
2315  */
2316 int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
2317 {
2318         struct uart_state *state;
2319         int ret = 0;
2320         struct device *tty_dev;
2321
2322         BUG_ON(in_interrupt());
2323
2324         if (port->line >= drv->nr)
2325                 return -EINVAL;
2326
2327         state = drv->state + port->line;
2328
2329         mutex_lock(&port_mutex);
2330         mutex_lock(&state->mutex);
2331         if (state->port) {
2332                 ret = -EINVAL;
2333                 goto out;
2334         }
2335
2336         state->port = port;
2337         state->pm_state = -1;
2338
2339         port->cons = drv->cons;
2340         port->info = state->info;
2341
2342         /*
2343          * If this port is a console, then the spinlock is already
2344          * initialised.
2345          */
2346         if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
2347                 spin_lock_init(&port->lock);
2348                 lockdep_set_class(&port->lock, &port_lock_key);
2349         }
2350
2351         uart_configure_port(drv, state, port);
2352
2353         /*
2354          * Register the port whether it's detected or not.  This allows
2355          * setserial to be used to alter this ports parameters.
2356          */
2357         tty_dev = tty_register_device(drv->tty_driver, port->line, port->dev);
2358         if (likely(!IS_ERR(tty_dev))) {
2359                 device_can_wakeup(tty_dev) = 1;
2360                 device_set_wakeup_enable(tty_dev, 0);
2361         } else
2362                 printk(KERN_ERR "Cannot register tty device on line %d\n",
2363                        port->line);
2364
2365         /*
2366          * Ensure UPF_DEAD is not set.
2367          */
2368         port->flags &= ~UPF_DEAD;
2369
2370  out:
2371         mutex_unlock(&state->mutex);
2372         mutex_unlock(&port_mutex);
2373
2374         return ret;
2375 }
2376
2377 /**
2378  *      uart_remove_one_port - detach a driver defined port structure
2379  *      @drv: pointer to the uart low level driver structure for this port
2380  *      @port: uart port structure for this port
2381  *
2382  *      This unhooks (and hangs up) the specified port structure from the
2383  *      core driver.  No further calls will be made to the low-level code
2384  *      for this port.
2385  */
2386 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *port)
2387 {
2388         struct uart_state *state = drv->state + port->line;
2389         struct uart_info *info;
2390
2391         BUG_ON(in_interrupt());
2392
2393         if (state->port != port)
2394                 printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2395                         state->port, port);
2396
2397         mutex_lock(&port_mutex);
2398
2399         /*
2400          * Mark the port "dead" - this prevents any opens from
2401          * succeeding while we shut down the port.
2402          */
2403         mutex_lock(&state->mutex);
2404         port->flags |= UPF_DEAD;
2405         mutex_unlock(&state->mutex);
2406
2407         /*
2408          * Remove the devices from the tty layer
2409          */
2410         tty_unregister_device(drv->tty_driver, port->line);
2411
2412         info = state->info;
2413         if (info && info->tty)
2414                 tty_vhangup(info->tty);
2415
2416         /*
2417          * All users of this port should now be disconnected from
2418          * this driver, and the port shut down.  We should be the
2419          * only thread fiddling with this port from now on.
2420          */
2421         state->info = NULL;
2422
2423         /*
2424          * Free the port IO and memory resources, if any.
2425          */
2426         if (port->type != PORT_UNKNOWN)
2427                 port->ops->release_port(port);
2428
2429         /*
2430          * Indicate that there isn't a port here anymore.
2431          */
2432         port->type = PORT_UNKNOWN;
2433
2434         /*
2435          * Kill the tasklet, and free resources.
2436          */
2437         if (info) {
2438                 tasklet_kill(&info->tlet);
2439                 kfree(info);
2440         }
2441
2442         state->port = NULL;
2443         mutex_unlock(&port_mutex);
2444
2445         return 0;
2446 }
2447
2448 /*
2449  *      Are the two ports equivalent?
2450  */
2451 int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2452 {
2453         if (port1->iotype != port2->iotype)
2454                 return 0;
2455
2456         switch (port1->iotype) {
2457         case UPIO_PORT:
2458                 return (port1->iobase == port2->iobase);
2459         case UPIO_HUB6:
2460                 return (port1->iobase == port2->iobase) &&
2461                        (port1->hub6   == port2->hub6);
2462         case UPIO_MEM:
2463         case UPIO_MEM32:
2464         case UPIO_AU:
2465         case UPIO_TSI:
2466         case UPIO_DWAPB:
2467                 return (port1->mapbase == port2->mapbase);
2468         }
2469         return 0;
2470 }
2471 EXPORT_SYMBOL(uart_match_port);
2472
2473 EXPORT_SYMBOL(uart_write_wakeup);
2474 EXPORT_SYMBOL(uart_register_driver);
2475 EXPORT_SYMBOL(uart_unregister_driver);
2476 EXPORT_SYMBOL(uart_suspend_port);
2477 EXPORT_SYMBOL(uart_resume_port);
2478 EXPORT_SYMBOL(uart_add_one_port);
2479 EXPORT_SYMBOL(uart_remove_one_port);
2480
2481 MODULE_DESCRIPTION("Serial driver core");
2482 MODULE_LICENSE("GPL");