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/slab.h>
  26#include <linux/init.h>
  27#include <linux/console.h>
  28#include <linux/proc_fs.h>
  29#include <linux/seq_file.h>
  30#include <linux/device.h>
  31#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
  32#include <linux/serial_core.h>
  33#include <linux/delay.h>
  34#include <linux/mutex.h>
  35
  36#include <asm/irq.h>
  37#include <asm/uaccess.h>
  38
  39/*
  40 * This is used to lock changes in serial line configuration.
  41 */
  42static DEFINE_MUTEX(port_mutex);
  43
  44/*
  45 * lockdep: port->lock is initialized in two places, but we
  46 *          want only one lock-class:
  47 */
  48static struct lock_class_key port_lock_key;
  49
  50#define HIGH_BITS_OFFSET	((sizeof(long)-sizeof(int))*8)
  51
  52#ifdef CONFIG_SERIAL_CORE_CONSOLE
  53#define uart_console(port)	((port)->cons && (port)->cons->index == (port)->line)
  54#else
  55#define uart_console(port)	(0)
  56#endif
  57
  58static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
  59					struct ktermios *old_termios);
  60static void __uart_wait_until_sent(struct uart_port *port, int timeout);
  61static void uart_change_pm(struct uart_state *state, int pm_state);
  62
 
 
  63/*
  64 * This routine is used by the interrupt handler to schedule processing in
  65 * the software interrupt portion of the driver.
  66 */
  67void uart_write_wakeup(struct uart_port *port)
  68{
  69	struct uart_state *state = port->state;
  70	/*
  71	 * This means you called this function _after_ the port was
  72	 * closed.  No cookie for you.
  73	 */
  74	BUG_ON(!state);
  75	tasklet_schedule(&state->tlet);
  76}
  77
  78static void uart_stop(struct tty_struct *tty)
  79{
  80	struct uart_state *state = tty->driver_data;
  81	struct uart_port *port = state->uart_port;
  82	unsigned long flags;
  83
  84	spin_lock_irqsave(&port->lock, flags);
  85	port->ops->stop_tx(port);
  86	spin_unlock_irqrestore(&port->lock, flags);
  87}
  88
  89static void __uart_start(struct tty_struct *tty)
  90{
  91	struct uart_state *state = tty->driver_data;
  92	struct uart_port *port = state->uart_port;
  93
  94	if (!uart_circ_empty(&state->xmit) && state->xmit.buf &&
  95	    !tty->stopped && !tty->hw_stopped)
  96		port->ops->start_tx(port);
  97}
  98
  99static void uart_start(struct tty_struct *tty)
 100{
 101	struct uart_state *state = tty->driver_data;
 102	struct uart_port *port = state->uart_port;
 103	unsigned long flags;
 104
 105	spin_lock_irqsave(&port->lock, flags);
 106	__uart_start(tty);
 107	spin_unlock_irqrestore(&port->lock, flags);
 108}
 109
 110static void uart_tasklet_action(unsigned long data)
 111{
 112	struct uart_state *state = (struct uart_state *)data;
 113	tty_wakeup(state->port.tty);
 114}
 115
 116static inline void
 117uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
 118{
 119	unsigned long flags;
 120	unsigned int old;
 121
 122	spin_lock_irqsave(&port->lock, flags);
 123	old = port->mctrl;
 124	port->mctrl = (old & ~clear) | set;
 125	if (old != port->mctrl)
 126		port->ops->set_mctrl(port, port->mctrl);
 127	spin_unlock_irqrestore(&port->lock, flags);
 128}
 129
 130#define uart_set_mctrl(port, set)	uart_update_mctrl(port, set, 0)
 131#define uart_clear_mctrl(port, clear)	uart_update_mctrl(port, 0, clear)
 132
 133/*
 134 * Startup the port.  This will be called once per open.  All calls
 135 * will be serialised by the per-port mutex.
 136 */
 137static int uart_startup(struct tty_struct *tty, struct uart_state *state, int init_hw)
 
 138{
 139	struct uart_port *uport = state->uart_port;
 140	struct tty_port *port = &state->port;
 141	unsigned long page;
 142	int retval = 0;
 143
 144	if (port->flags & ASYNC_INITIALIZED)
 145		return 0;
 146
 147	/*
 148	 * Set the TTY IO error marker - we will only clear this
 149	 * once we have successfully opened the port.  Also set
 150	 * up the tty->alt_speed kludge
 151	 */
 152	set_bit(TTY_IO_ERROR, &tty->flags);
 153
 154	if (uport->type == PORT_UNKNOWN)
 155		return 0;
 156
 157	/*
 158	 * Initialise and allocate the transmit and temporary
 159	 * buffer.
 160	 */
 161	if (!state->xmit.buf) {
 162		/* This is protected by the per port mutex */
 163		page = get_zeroed_page(GFP_KERNEL);
 164		if (!page)
 165			return -ENOMEM;
 166
 167		state->xmit.buf = (unsigned char *) page;
 168		uart_circ_clear(&state->xmit);
 169	}
 170
 171	retval = uport->ops->startup(uport);
 172	if (retval == 0) {
 173		if (uart_console(uport) && uport->cons->cflag) {
 174			tty->termios->c_cflag = uport->cons->cflag;
 175			uport->cons->cflag = 0;
 176		}
 177		/*
 178		 * Initialise the hardware port settings.
 179		 */
 180		uart_change_speed(tty, state, NULL);
 181
 182		if (init_hw) {
 183			/*
 184			 * Setup the RTS and DTR signals once the
 185			 * port is open and ready to respond.
 186			 */
 187			if (tty->termios->c_cflag & CBAUD)
 188				uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
 189		}
 190
 191		if (port->flags & ASYNC_CTS_FLOW) {
 192			spin_lock_irq(&uport->lock);
 193			if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
 194				tty->hw_stopped = 1;
 195			spin_unlock_irq(&uport->lock);
 196		}
 197
 198		set_bit(ASYNCB_INITIALIZED, &port->flags);
 199
 200		clear_bit(TTY_IO_ERROR, &tty->flags);
 201	}
 202
 203	/*
 204	 * This is to allow setserial on this port. People may want to set
 205	 * port/irq/type and then reconfigure the port properly if it failed
 206	 * now.
 207	 */
 208	if (retval && capable(CAP_SYS_ADMIN))
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 209		retval = 0;
 210
 211	return retval;
 212}
 213
 214/*
 215 * This routine will shutdown a serial port; interrupts are disabled, and
 216 * DTR is dropped if the hangup on close termio flag is on.  Calls to
 217 * uart_shutdown are serialised by the per-port semaphore.
 218 */
 219static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
 220{
 221	struct uart_port *uport = state->uart_port;
 222	struct tty_port *port = &state->port;
 223
 224	/*
 225	 * Set the TTY IO error marker
 226	 */
 227	if (tty)
 228		set_bit(TTY_IO_ERROR, &tty->flags);
 229
 230	if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
 231		/*
 232		 * Turn off DTR and RTS early.
 233		 */
 234		if (!tty || (tty->termios->c_cflag & HUPCL))
 235			uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
 236
 237		/*
 238		 * clear delta_msr_wait queue to avoid mem leaks: we may free
 239		 * the irq here so the queue might never be woken up.  Note
 240		 * that we won't end up waiting on delta_msr_wait again since
 241		 * any outstanding file descriptors should be pointing at
 242		 * hung_up_tty_fops now.
 243		 */
 244		wake_up_interruptible(&port->delta_msr_wait);
 245
 246		/*
 247		 * Free the IRQ and disable the port.
 248		 */
 249		uport->ops->shutdown(uport);
 250
 251		/*
 252		 * Ensure that the IRQ handler isn't running on another CPU.
 253		 */
 254		synchronize_irq(uport->irq);
 255	}
 256
 257	/*
 258	 * kill off our tasklet
 
 
 259	 */
 260	tasklet_kill(&state->tlet);
 261
 262	/*
 263	 * Free the transmit buffer page.
 264	 */
 265	if (state->xmit.buf) {
 266		free_page((unsigned long)state->xmit.buf);
 267		state->xmit.buf = NULL;
 268	}
 269}
 270
 271/**
 272 *	uart_update_timeout - update per-port FIFO timeout.
 273 *	@port:  uart_port structure describing the port
 274 *	@cflag: termios cflag value
 275 *	@baud:  speed of the port
 276 *
 277 *	Set the port FIFO timeout value.  The @cflag value should
 278 *	reflect the actual hardware settings.
 279 */
 280void
 281uart_update_timeout(struct uart_port *port, unsigned int cflag,
 282		    unsigned int baud)
 283{
 284	unsigned int bits;
 285
 286	/* byte size and parity */
 287	switch (cflag & CSIZE) {
 288	case CS5:
 289		bits = 7;
 290		break;
 291	case CS6:
 292		bits = 8;
 293		break;
 294	case CS7:
 295		bits = 9;
 296		break;
 297	default:
 298		bits = 10;
 299		break; /* CS8 */
 300	}
 301
 302	if (cflag & CSTOPB)
 303		bits++;
 304	if (cflag & PARENB)
 305		bits++;
 306
 307	/*
 308	 * The total number of bits to be transmitted in the fifo.
 309	 */
 310	bits = bits * port->fifosize;
 311
 312	/*
 313	 * Figure the timeout to send the above number of bits.
 314	 * Add .02 seconds of slop
 315	 */
 316	port->timeout = (HZ * bits) / baud + HZ/50;
 317}
 318
 319EXPORT_SYMBOL(uart_update_timeout);
 320
 321/**
 322 *	uart_get_baud_rate - return baud rate for a particular port
 323 *	@port: uart_port structure describing the port in question.
 324 *	@termios: desired termios settings.
 325 *	@old: old termios (or NULL)
 326 *	@min: minimum acceptable baud rate
 327 *	@max: maximum acceptable baud rate
 328 *
 329 *	Decode the termios structure into a numeric baud rate,
 330 *	taking account of the magic 38400 baud rate (with spd_*
 331 *	flags), and mapping the %B0 rate to 9600 baud.
 332 *
 333 *	If the new baud rate is invalid, try the old termios setting.
 334 *	If it's still invalid, we try 9600 baud.
 335 *
 336 *	Update the @termios structure to reflect the baud rate
 337 *	we're actually going to be using. Don't do this for the case
 338 *	where B0 is requested ("hang up").
 339 */
 340unsigned int
 341uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
 342		   struct ktermios *old, unsigned int min, unsigned int max)
 343{
 344	unsigned int try, baud, altbaud = 38400;
 345	int hung_up = 0;
 346	upf_t flags = port->flags & UPF_SPD_MASK;
 347
 348	if (flags == UPF_SPD_HI)
 349		altbaud = 57600;
 350	else if (flags == UPF_SPD_VHI)
 351		altbaud = 115200;
 352	else if (flags == UPF_SPD_SHI)
 353		altbaud = 230400;
 354	else if (flags == UPF_SPD_WARP)
 355		altbaud = 460800;
 356
 357	for (try = 0; try < 2; try++) {
 358		baud = tty_termios_baud_rate(termios);
 359
 360		/*
 361		 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
 362		 * Die! Die! Die!
 363		 */
 364		if (baud == 38400)
 365			baud = altbaud;
 366
 367		/*
 368		 * Special case: B0 rate.
 369		 */
 370		if (baud == 0) {
 371			hung_up = 1;
 372			baud = 9600;
 373		}
 374
 375		if (baud >= min && baud <= max)
 376			return baud;
 377
 378		/*
 379		 * Oops, the quotient was zero.  Try again with
 380		 * the old baud rate if possible.
 381		 */
 382		termios->c_cflag &= ~CBAUD;
 383		if (old) {
 384			baud = tty_termios_baud_rate(old);
 385			if (!hung_up)
 386				tty_termios_encode_baud_rate(termios,
 387								baud, baud);
 388			old = NULL;
 389			continue;
 390		}
 391
 392		/*
 393		 * As a last resort, if the range cannot be met then clip to
 394		 * the nearest chip supported rate.
 395		 */
 396		if (!hung_up) {
 397			if (baud <= min)
 398				tty_termios_encode_baud_rate(termios,
 399							min + 1, min + 1);
 400			else
 401				tty_termios_encode_baud_rate(termios,
 402							max - 1, max - 1);
 403		}
 404	}
 405	/* Should never happen */
 406	WARN_ON(1);
 407	return 0;
 408}
 409
 410EXPORT_SYMBOL(uart_get_baud_rate);
 411
 412/**
 413 *	uart_get_divisor - return uart clock divisor
 414 *	@port: uart_port structure describing the port.
 415 *	@baud: desired baud rate
 416 *
 417 *	Calculate the uart clock divisor for the port.
 418 */
 419unsigned int
 420uart_get_divisor(struct uart_port *port, unsigned int baud)
 421{
 422	unsigned int quot;
 423
 424	/*
 425	 * Old custom speed handling.
 426	 */
 427	if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
 428		quot = port->custom_divisor;
 429	else
 430		quot = (port->uartclk + (8 * baud)) / (16 * baud);
 431
 432	return quot;
 433}
 434
 435EXPORT_SYMBOL(uart_get_divisor);
 436
 437/* FIXME: Consistent locking policy */
 438static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
 439					struct ktermios *old_termios)
 440{
 441	struct tty_port *port = &state->port;
 442	struct uart_port *uport = state->uart_port;
 443	struct ktermios *termios;
 444
 445	/*
 446	 * If we have no tty, termios, or the port does not exist,
 447	 * then we can't set the parameters for this port.
 448	 */
 449	if (!tty || !tty->termios || uport->type == PORT_UNKNOWN)
 450		return;
 451
 452	termios = tty->termios;
 453
 454	/*
 455	 * Set flags based on termios cflag
 456	 */
 457	if (termios->c_cflag & CRTSCTS)
 458		set_bit(ASYNCB_CTS_FLOW, &port->flags);
 459	else
 460		clear_bit(ASYNCB_CTS_FLOW, &port->flags);
 461
 462	if (termios->c_cflag & CLOCAL)
 463		clear_bit(ASYNCB_CHECK_CD, &port->flags);
 464	else
 465		set_bit(ASYNCB_CHECK_CD, &port->flags);
 466
 467	uport->ops->set_termios(uport, termios, old_termios);
 468}
 469
 470static inline int __uart_put_char(struct uart_port *port,
 471				struct circ_buf *circ, unsigned char c)
 472{
 473	unsigned long flags;
 474	int ret = 0;
 475
 476	if (!circ->buf)
 477		return 0;
 478
 479	spin_lock_irqsave(&port->lock, flags);
 480	if (uart_circ_chars_free(circ) != 0) {
 481		circ->buf[circ->head] = c;
 482		circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
 483		ret = 1;
 484	}
 485	spin_unlock_irqrestore(&port->lock, flags);
 486	return ret;
 487}
 488
 489static int uart_put_char(struct tty_struct *tty, unsigned char ch)
 490{
 491	struct uart_state *state = tty->driver_data;
 492
 493	return __uart_put_char(state->uart_port, &state->xmit, ch);
 494}
 495
 496static void uart_flush_chars(struct tty_struct *tty)
 497{
 498	uart_start(tty);
 499}
 500
 501static int uart_write(struct tty_struct *tty,
 502					const unsigned char *buf, int count)
 503{
 504	struct uart_state *state = tty->driver_data;
 505	struct uart_port *port;
 506	struct circ_buf *circ;
 507	unsigned long flags;
 508	int c, ret = 0;
 509
 510	/*
 511	 * This means you called this function _after_ the port was
 512	 * closed.  No cookie for you.
 513	 */
 514	if (!state) {
 515		WARN_ON(1);
 516		return -EL3HLT;
 517	}
 518
 519	port = state->uart_port;
 520	circ = &state->xmit;
 521
 522	if (!circ->buf)
 523		return 0;
 524
 525	spin_lock_irqsave(&port->lock, flags);
 526	while (1) {
 527		c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
 528		if (count < c)
 529			c = count;
 530		if (c <= 0)
 531			break;
 532		memcpy(circ->buf + circ->head, buf, c);
 533		circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
 534		buf += c;
 535		count -= c;
 536		ret += c;
 537	}
 538	spin_unlock_irqrestore(&port->lock, flags);
 539
 540	uart_start(tty);
 541	return ret;
 542}
 543
 544static int uart_write_room(struct tty_struct *tty)
 545{
 546	struct uart_state *state = tty->driver_data;
 547	unsigned long flags;
 548	int ret;
 549
 550	spin_lock_irqsave(&state->uart_port->lock, flags);
 551	ret = uart_circ_chars_free(&state->xmit);
 552	spin_unlock_irqrestore(&state->uart_port->lock, flags);
 553	return ret;
 554}
 555
 556static int uart_chars_in_buffer(struct tty_struct *tty)
 557{
 558	struct uart_state *state = tty->driver_data;
 559	unsigned long flags;
 560	int ret;
 561
 562	spin_lock_irqsave(&state->uart_port->lock, flags);
 563	ret = uart_circ_chars_pending(&state->xmit);
 564	spin_unlock_irqrestore(&state->uart_port->lock, flags);
 565	return ret;
 566}
 567
 568static void uart_flush_buffer(struct tty_struct *tty)
 569{
 570	struct uart_state *state = tty->driver_data;
 571	struct uart_port *port;
 572	unsigned long flags;
 573
 574	/*
 575	 * This means you called this function _after_ the port was
 576	 * closed.  No cookie for you.
 577	 */
 578	if (!state) {
 579		WARN_ON(1);
 580		return;
 581	}
 582
 583	port = state->uart_port;
 584	pr_debug("uart_flush_buffer(%d) called\n", tty->index);
 585
 586	spin_lock_irqsave(&port->lock, flags);
 587	uart_circ_clear(&state->xmit);
 588	if (port->ops->flush_buffer)
 589		port->ops->flush_buffer(port);
 590	spin_unlock_irqrestore(&port->lock, flags);
 591	tty_wakeup(tty);
 592}
 593
 594/*
 595 * This function is used to send a high-priority XON/XOFF character to
 596 * the device
 597 */
 598static void uart_send_xchar(struct tty_struct *tty, char ch)
 599{
 600	struct uart_state *state = tty->driver_data;
 601	struct uart_port *port = state->uart_port;
 602	unsigned long flags;
 603
 604	if (port->ops->send_xchar)
 605		port->ops->send_xchar(port, ch);
 606	else {
 607		port->x_char = ch;
 608		if (ch) {
 609			spin_lock_irqsave(&port->lock, flags);
 610			port->ops->start_tx(port);
 611			spin_unlock_irqrestore(&port->lock, flags);
 612		}
 613	}
 614}
 615
 616static void uart_throttle(struct tty_struct *tty)
 617{
 618	struct uart_state *state = tty->driver_data;
 619
 620	if (I_IXOFF(tty))
 621		uart_send_xchar(tty, STOP_CHAR(tty));
 622
 623	if (tty->termios->c_cflag & CRTSCTS)
 624		uart_clear_mctrl(state->uart_port, TIOCM_RTS);
 625}
 626
 627static void uart_unthrottle(struct tty_struct *tty)
 628{
 629	struct uart_state *state = tty->driver_data;
 630	struct uart_port *port = state->uart_port;
 631
 632	if (I_IXOFF(tty)) {
 633		if (port->x_char)
 634			port->x_char = 0;
 635		else
 636			uart_send_xchar(tty, START_CHAR(tty));
 637	}
 638
 639	if (tty->termios->c_cflag & CRTSCTS)
 640		uart_set_mctrl(port, TIOCM_RTS);
 641}
 642
 643static int uart_get_info(struct uart_state *state,
 644			 struct serial_struct __user *retinfo)
 645{
 646	struct uart_port *uport = state->uart_port;
 647	struct tty_port *port = &state->port;
 648	struct serial_struct tmp;
 649
 650	memset(&tmp, 0, sizeof(tmp));
 651
 652	/* Ensure the state we copy is consistent and no hardware changes
 653	   occur as we go */
 654	mutex_lock(&port->mutex);
 655
 656	tmp.type	    = uport->type;
 657	tmp.line	    = uport->line;
 658	tmp.port	    = uport->iobase;
 659	if (HIGH_BITS_OFFSET)
 660		tmp.port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
 661	tmp.irq		    = uport->irq;
 662	tmp.flags	    = uport->flags;
 663	tmp.xmit_fifo_size  = uport->fifosize;
 664	tmp.baud_base	    = uport->uartclk / 16;
 665	tmp.close_delay	    = port->close_delay / 10;
 666	tmp.closing_wait    = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
 667				ASYNC_CLOSING_WAIT_NONE :
 668				port->closing_wait / 10;
 669	tmp.custom_divisor  = uport->custom_divisor;
 670	tmp.hub6	    = uport->hub6;
 671	tmp.io_type         = uport->iotype;
 672	tmp.iomem_reg_shift = uport->regshift;
 673	tmp.iomem_base      = (void *)(unsigned long)uport->mapbase;
 674
 675	mutex_unlock(&port->mutex);
 676
 677	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
 678		return -EFAULT;
 679	return 0;
 680}
 681
 682static int uart_set_info(struct tty_struct *tty, struct uart_state *state,
 683			 struct serial_struct __user *newinfo)
 684{
 685	struct serial_struct new_serial;
 686	struct uart_port *uport = state->uart_port;
 687	struct tty_port *port = &state->port;
 688	unsigned long new_port;
 689	unsigned int change_irq, change_port, closing_wait;
 690	unsigned int old_custom_divisor, close_delay;
 691	upf_t old_flags, new_flags;
 692	int retval = 0;
 693
 694	if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
 695		return -EFAULT;
 696
 697	new_port = new_serial.port;
 698	if (HIGH_BITS_OFFSET)
 699		new_port += (unsigned long) new_serial.port_high << HIGH_BITS_OFFSET;
 700
 701	new_serial.irq = irq_canonicalize(new_serial.irq);
 702	close_delay = new_serial.close_delay * 10;
 703	closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
 704			ASYNC_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
 
 705
 706	/*
 707	 * This semaphore protects port->count.  It is also
 708	 * very useful to prevent opens.  Also, take the
 709	 * port configuration semaphore to make sure that a
 710	 * module insertion/removal doesn't change anything
 711	 * under us.
 712	 */
 713	mutex_lock(&port->mutex);
 714
 715	change_irq  = !(uport->flags & UPF_FIXED_PORT)
 716		&& new_serial.irq != uport->irq;
 717
 718	/*
 719	 * Since changing the 'type' of the port changes its resource
 720	 * allocations, we should treat type changes the same as
 721	 * IO port changes.
 722	 */
 723	change_port = !(uport->flags & UPF_FIXED_PORT)
 724		&& (new_port != uport->iobase ||
 725		    (unsigned long)new_serial.iomem_base != uport->mapbase ||
 726		    new_serial.hub6 != uport->hub6 ||
 727		    new_serial.io_type != uport->iotype ||
 728		    new_serial.iomem_reg_shift != uport->regshift ||
 729		    new_serial.type != uport->type);
 730
 731	old_flags = uport->flags;
 732	new_flags = new_serial.flags;
 733	old_custom_divisor = uport->custom_divisor;
 734
 735	if (!capable(CAP_SYS_ADMIN)) {
 736		retval = -EPERM;
 737		if (change_irq || change_port ||
 738		    (new_serial.baud_base != uport->uartclk / 16) ||
 739		    (close_delay != port->close_delay) ||
 740		    (closing_wait != port->closing_wait) ||
 741		    (new_serial.xmit_fifo_size &&
 742		     new_serial.xmit_fifo_size != uport->fifosize) ||
 743		    (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
 744			goto exit;
 745		uport->flags = ((uport->flags & ~UPF_USR_MASK) |
 746			       (new_flags & UPF_USR_MASK));
 747		uport->custom_divisor = new_serial.custom_divisor;
 748		goto check_and_exit;
 749	}
 750
 751	/*
 752	 * Ask the low level driver to verify the settings.
 753	 */
 754	if (uport->ops->verify_port)
 755		retval = uport->ops->verify_port(uport, &new_serial);
 756
 757	if ((new_serial.irq >= nr_irqs) || (new_serial.irq < 0) ||
 758	    (new_serial.baud_base < 9600))
 759		retval = -EINVAL;
 760
 761	if (retval)
 762		goto exit;
 763
 764	if (change_port || change_irq) {
 765		retval = -EBUSY;
 766
 767		/*
 768		 * Make sure that we are the sole user of this port.
 769		 */
 770		if (tty_port_users(port) > 1)
 771			goto exit;
 772
 773		/*
 774		 * We need to shutdown the serial port at the old
 775		 * port/type/irq combination.
 776		 */
 777		uart_shutdown(tty, state);
 778	}
 779
 780	if (change_port) {
 781		unsigned long old_iobase, old_mapbase;
 782		unsigned int old_type, old_iotype, old_hub6, old_shift;
 783
 784		old_iobase = uport->iobase;
 785		old_mapbase = uport->mapbase;
 786		old_type = uport->type;
 787		old_hub6 = uport->hub6;
 788		old_iotype = uport->iotype;
 789		old_shift = uport->regshift;
 790
 791		/*
 792		 * Free and release old regions
 793		 */
 794		if (old_type != PORT_UNKNOWN)
 795			uport->ops->release_port(uport);
 796
 797		uport->iobase = new_port;
 798		uport->type = new_serial.type;
 799		uport->hub6 = new_serial.hub6;
 800		uport->iotype = new_serial.io_type;
 801		uport->regshift = new_serial.iomem_reg_shift;
 802		uport->mapbase = (unsigned long)new_serial.iomem_base;
 803
 804		/*
 805		 * Claim and map the new regions
 806		 */
 807		if (uport->type != PORT_UNKNOWN) {
 808			retval = uport->ops->request_port(uport);
 809		} else {
 810			/* Always success - Jean II */
 811			retval = 0;
 812		}
 813
 814		/*
 815		 * If we fail to request resources for the
 816		 * new port, try to restore the old settings.
 817		 */
 818		if (retval && old_type != PORT_UNKNOWN) {
 819			uport->iobase = old_iobase;
 820			uport->type = old_type;
 821			uport->hub6 = old_hub6;
 822			uport->iotype = old_iotype;
 823			uport->regshift = old_shift;
 824			uport->mapbase = old_mapbase;
 825			retval = uport->ops->request_port(uport);
 826			/*
 827			 * If we failed to restore the old settings,
 828			 * we fail like this.
 829			 */
 830			if (retval)
 831				uport->type = PORT_UNKNOWN;
 832
 833			/*
 834			 * We failed anyway.
 835			 */
 836			retval = -EBUSY;
 837			/* Added to return the correct error -Ram Gupta */
 838			goto exit;
 839		}
 840	}
 841
 842	if (change_irq)
 843		uport->irq      = new_serial.irq;
 844	if (!(uport->flags & UPF_FIXED_PORT))
 845		uport->uartclk  = new_serial.baud_base * 16;
 846	uport->flags            = (uport->flags & ~UPF_CHANGE_MASK) |
 847				 (new_flags & UPF_CHANGE_MASK);
 848	uport->custom_divisor   = new_serial.custom_divisor;
 849	port->close_delay     = close_delay;
 850	port->closing_wait    = closing_wait;
 851	if (new_serial.xmit_fifo_size)
 852		uport->fifosize = new_serial.xmit_fifo_size;
 853	if (port->tty)
 854		port->tty->low_latency =
 855			(uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
 856
 857 check_and_exit:
 858	retval = 0;
 859	if (uport->type == PORT_UNKNOWN)
 860		goto exit;
 861	if (port->flags & ASYNC_INITIALIZED) {
 862		if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
 863		    old_custom_divisor != uport->custom_divisor) {
 864			/*
 865			 * If they're setting up a custom divisor or speed,
 866			 * instead of clearing it, then bitch about it. No
 867			 * need to rate-limit; it's CAP_SYS_ADMIN only.
 868			 */
 869			if (uport->flags & UPF_SPD_MASK) {
 870				char buf[64];
 871				printk(KERN_NOTICE
 872				       "%s sets custom speed on %s. This "
 873				       "is deprecated.\n", current->comm,
 874				       tty_name(port->tty, buf));
 875			}
 876			uart_change_speed(tty, state, NULL);
 877		}
 878	} else
 879		retval = uart_startup(tty, state, 1);
 880 exit:
 881	mutex_unlock(&port->mutex);
 882	return retval;
 883}
 884
 885/**
 886 *	uart_get_lsr_info	-	get line status register info
 887 *	@tty: tty associated with the UART
 888 *	@state: UART being queried
 889 *	@value: returned modem value
 890 *
 891 *	Note: uart_ioctl protects us against hangups.
 892 */
 893static int uart_get_lsr_info(struct tty_struct *tty,
 894			struct uart_state *state, unsigned int __user *value)
 895{
 896	struct uart_port *uport = state->uart_port;
 897	unsigned int result;
 898
 899	result = uport->ops->tx_empty(uport);
 900
 901	/*
 902	 * If we're about to load something into the transmit
 903	 * register, we'll pretend the transmitter isn't empty to
 904	 * avoid a race condition (depending on when the transmit
 905	 * interrupt happens).
 906	 */
 907	if (uport->x_char ||
 908	    ((uart_circ_chars_pending(&state->xmit) > 0) &&
 909	     !tty->stopped && !tty->hw_stopped))
 910		result &= ~TIOCSER_TEMT;
 911
 912	return put_user(result, value);
 913}
 914
 915static int uart_tiocmget(struct tty_struct *tty)
 916{
 917	struct uart_state *state = tty->driver_data;
 918	struct tty_port *port = &state->port;
 919	struct uart_port *uport = state->uart_port;
 920	int result = -EIO;
 921
 922	mutex_lock(&port->mutex);
 923	if (!(tty->flags & (1 << TTY_IO_ERROR))) {
 924		result = uport->mctrl;
 925		spin_lock_irq(&uport->lock);
 926		result |= uport->ops->get_mctrl(uport);
 927		spin_unlock_irq(&uport->lock);
 928	}
 929	mutex_unlock(&port->mutex);
 930
 931	return result;
 932}
 933
 934static int
 935uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
 936{
 937	struct uart_state *state = tty->driver_data;
 938	struct uart_port *uport = state->uart_port;
 939	struct tty_port *port = &state->port;
 940	int ret = -EIO;
 941
 942	mutex_lock(&port->mutex);
 943	if (!(tty->flags & (1 << TTY_IO_ERROR))) {
 944		uart_update_mctrl(uport, set, clear);
 945		ret = 0;
 946	}
 947	mutex_unlock(&port->mutex);
 948	return ret;
 949}
 950
 951static int uart_break_ctl(struct tty_struct *tty, int break_state)
 952{
 953	struct uart_state *state = tty->driver_data;
 954	struct tty_port *port = &state->port;
 955	struct uart_port *uport = state->uart_port;
 956
 957	mutex_lock(&port->mutex);
 958
 959	if (uport->type != PORT_UNKNOWN)
 960		uport->ops->break_ctl(uport, break_state);
 961
 962	mutex_unlock(&port->mutex);
 963	return 0;
 964}
 965
 966static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
 967{
 968	struct uart_port *uport = state->uart_port;
 969	struct tty_port *port = &state->port;
 970	int flags, ret;
 971
 972	if (!capable(CAP_SYS_ADMIN))
 973		return -EPERM;
 974
 975	/*
 976	 * Take the per-port semaphore.  This prevents count from
 977	 * changing, and hence any extra opens of the port while
 978	 * we're auto-configuring.
 979	 */
 980	if (mutex_lock_interruptible(&port->mutex))
 981		return -ERESTARTSYS;
 982
 983	ret = -EBUSY;
 984	if (tty_port_users(port) == 1) {
 985		uart_shutdown(tty, state);
 986
 987		/*
 988		 * If we already have a port type configured,
 989		 * we must release its resources.
 990		 */
 991		if (uport->type != PORT_UNKNOWN)
 992			uport->ops->release_port(uport);
 993
 994		flags = UART_CONFIG_TYPE;
 995		if (uport->flags & UPF_AUTO_IRQ)
 996			flags |= UART_CONFIG_IRQ;
 997
 998		/*
 999		 * This will claim the ports resources if
1000		 * a port is found.
1001		 */
1002		uport->ops->config_port(uport, flags);
1003
1004		ret = uart_startup(tty, state, 1);
1005	}
1006	mutex_unlock(&port->mutex);
1007	return ret;
1008}
1009
1010/*
1011 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1012 * - mask passed in arg for lines of interest
1013 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1014 * Caller should use TIOCGICOUNT to see which one it was
1015 *
1016 * FIXME: This wants extracting into a common all driver implementation
1017 * of TIOCMWAIT using tty_port.
1018 */
1019static int
1020uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1021{
1022	struct uart_port *uport = state->uart_port;
1023	struct tty_port *port = &state->port;
1024	DECLARE_WAITQUEUE(wait, current);
1025	struct uart_icount cprev, cnow;
1026	int ret;
1027
1028	/*
1029	 * note the counters on entry
1030	 */
1031	spin_lock_irq(&uport->lock);
1032	memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1033
1034	/*
1035	 * Force modem status interrupts on
1036	 */
1037	uport->ops->enable_ms(uport);
1038	spin_unlock_irq(&uport->lock);
1039
1040	add_wait_queue(&port->delta_msr_wait, &wait);
1041	for (;;) {
1042		spin_lock_irq(&uport->lock);
1043		memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1044		spin_unlock_irq(&uport->lock);
1045
1046		set_current_state(TASK_INTERRUPTIBLE);
1047
1048		if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1049		    ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1050		    ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
1051		    ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1052			ret = 0;
1053			break;
1054		}
1055
1056		schedule();
1057
1058		/* see if a signal did it */
1059		if (signal_pending(current)) {
1060			ret = -ERESTARTSYS;
1061			break;
1062		}
1063
1064		cprev = cnow;
1065	}
1066
1067	current->state = TASK_RUNNING;
1068	remove_wait_queue(&port->delta_msr_wait, &wait);
1069
1070	return ret;
1071}
1072
1073/*
1074 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1075 * Return: write counters to the user passed counter struct
1076 * NB: both 1->0 and 0->1 transitions are counted except for
1077 *     RI where only 0->1 is counted.
1078 */
1079static int uart_get_icount(struct tty_struct *tty,
1080			  struct serial_icounter_struct *icount)
1081{
1082	struct uart_state *state = tty->driver_data;
1083	struct uart_icount cnow;
1084	struct uart_port *uport = state->uart_port;
1085
1086	spin_lock_irq(&uport->lock);
1087	memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1088	spin_unlock_irq(&uport->lock);
1089
1090	icount->cts         = cnow.cts;
1091	icount->dsr         = cnow.dsr;
1092	icount->rng         = cnow.rng;
1093	icount->dcd         = cnow.dcd;
1094	icount->rx          = cnow.rx;
1095	icount->tx          = cnow.tx;
1096	icount->frame       = cnow.frame;
1097	icount->overrun     = cnow.overrun;
1098	icount->parity      = cnow.parity;
1099	icount->brk         = cnow.brk;
1100	icount->buf_overrun = cnow.buf_overrun;
1101
1102	return 0;
1103}
1104
1105/*
1106 * Called via sys_ioctl.  We can use spin_lock_irq() here.
1107 */
1108static int
1109uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1110	   unsigned long arg)
1111{
1112	struct uart_state *state = tty->driver_data;
1113	struct tty_port *port = &state->port;
1114	void __user *uarg = (void __user *)arg;
1115	int ret = -ENOIOCTLCMD;
1116
1117
1118	/*
1119	 * These ioctls don't rely on the hardware to be present.
1120	 */
1121	switch (cmd) {
1122	case TIOCGSERIAL:
1123		ret = uart_get_info(state, uarg);
1124		break;
1125
1126	case TIOCSSERIAL:
1127		ret = uart_set_info(tty, state, uarg);
1128		break;
1129
1130	case TIOCSERCONFIG:
1131		ret = uart_do_autoconfig(tty, state);
1132		break;
1133
1134	case TIOCSERGWILD: /* obsolete */
1135	case TIOCSERSWILD: /* obsolete */
1136		ret = 0;
1137		break;
1138	}
1139
1140	if (ret != -ENOIOCTLCMD)
1141		goto out;
1142
1143	if (tty->flags & (1 << TTY_IO_ERROR)) {
1144		ret = -EIO;
1145		goto out;
1146	}
1147
1148	/*
1149	 * The following should only be used when hardware is present.
1150	 */
1151	switch (cmd) {
1152	case TIOCMIWAIT:
1153		ret = uart_wait_modem_status(state, arg);
1154		break;
1155	}
1156
1157	if (ret != -ENOIOCTLCMD)
1158		goto out;
1159
1160	mutex_lock(&port->mutex);
1161
1162	if (tty->flags & (1 << TTY_IO_ERROR)) {
1163		ret = -EIO;
1164		goto out_up;
1165	}
1166
1167	/*
1168	 * All these rely on hardware being present and need to be
1169	 * protected against the tty being hung up.
1170	 */
1171	switch (cmd) {
1172	case TIOCSERGETLSR: /* Get line status register */
1173		ret = uart_get_lsr_info(tty, state, uarg);
1174		break;
1175
1176	default: {
1177		struct uart_port *uport = state->uart_port;
1178		if (uport->ops->ioctl)
1179			ret = uport->ops->ioctl(uport, cmd, arg);
1180		break;
1181	}
1182	}
1183out_up:
1184	mutex_unlock(&port->mutex);
1185out:
1186	return ret;
1187}
1188
1189static void uart_set_ldisc(struct tty_struct *tty)
1190{
1191	struct uart_state *state = tty->driver_data;
1192	struct uart_port *uport = state->uart_port;
1193
1194	if (uport->ops->set_ldisc)
1195		uport->ops->set_ldisc(uport, tty->termios->c_line);
1196}
1197
1198static void uart_set_termios(struct tty_struct *tty,
1199						struct ktermios *old_termios)
1200{
1201	struct uart_state *state = tty->driver_data;
1202	unsigned long flags;
1203	unsigned int cflag = tty->termios->c_cflag;
1204
1205
1206	/*
1207	 * These are the bits that are used to setup various
1208	 * flags in the low level driver. We can ignore the Bfoo
1209	 * bits in c_cflag; c_[io]speed will always be set
1210	 * appropriately by set_termios() in tty_ioctl.c
1211	 */
1212#define RELEVANT_IFLAG(iflag)	((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
1213	if ((cflag ^ old_termios->c_cflag) == 0 &&
1214	    tty->termios->c_ospeed == old_termios->c_ospeed &&
1215	    tty->termios->c_ispeed == old_termios->c_ispeed &&
1216	    RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0) {
1217		return;
1218	}
1219
1220	uart_change_speed(tty, state, old_termios);
1221
1222	/* Handle transition to B0 status */
1223	if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1224		uart_clear_mctrl(state->uart_port, TIOCM_RTS | TIOCM_DTR);
1225	/* Handle transition away from B0 status */
1226	else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1227		unsigned int mask = TIOCM_DTR;
1228		if (!(cflag & CRTSCTS) ||
1229		    !test_bit(TTY_THROTTLED, &tty->flags))
1230			mask |= TIOCM_RTS;
1231		uart_set_mctrl(state->uart_port, mask);
1232	}
1233
1234	/* Handle turning off CRTSCTS */
1235	if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
1236		spin_lock_irqsave(&state->uart_port->lock, flags);
1237		tty->hw_stopped = 0;
1238		__uart_start(tty);
1239		spin_unlock_irqrestore(&state->uart_port->lock, flags);
1240	}
1241	/* Handle turning on CRTSCTS */
1242	else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
1243		spin_lock_irqsave(&state->uart_port->lock, flags);
1244		if (!(state->uart_port->ops->get_mctrl(state->uart_port) & TIOCM_CTS)) {
1245			tty->hw_stopped = 1;
1246			state->uart_port->ops->stop_tx(state->uart_port);
1247		}
1248		spin_unlock_irqrestore(&state->uart_port->lock, flags);
1249	}
1250}
1251
1252/*
1253 * In 2.4.5, calls to this will be serialized via the BKL in
1254 *  linux/drivers/char/tty_io.c:tty_release()
1255 *  linux/drivers/char/tty_io.c:do_tty_handup()
1256 */
1257static void uart_close(struct tty_struct *tty, struct file *filp)
1258{
1259	struct uart_state *state = tty->driver_data;
1260	struct tty_port *port;
1261	struct uart_port *uport;
1262	unsigned long flags;
1263
1264	BUG_ON(!tty_locked());
1265
1266	if (!state)
1267		return;
1268
1269	uport = state->uart_port;
1270	port = &state->port;
1271
1272	pr_debug("uart_close(%d) called\n", uport->line);
1273
1274	mutex_lock(&port->mutex);
1275	spin_lock_irqsave(&port->lock, flags);
1276
1277	if (tty_hung_up_p(filp)) {
1278		spin_unlock_irqrestore(&port->lock, flags);
1279		goto done;
1280	}
1281
1282	if ((tty->count == 1) && (port->count != 1)) {
1283		/*
1284		 * Uh, oh.  tty->count is 1, which means that the tty
1285		 * structure will be freed.  port->count should always
1286		 * be one in these conditions.  If it's greater than
1287		 * one, we've got real problems, since it means the
1288		 * serial port won't be shutdown.
1289		 */
1290		printk(KERN_ERR "uart_close: bad serial port count; tty->count is 1, "
1291		       "port->count is %d\n", port->count);
1292		port->count = 1;
1293	}
1294	if (--port->count < 0) {
1295		printk(KERN_ERR "uart_close: bad serial port count for %s: %d\n",
1296		       tty->name, port->count);
1297		port->count = 0;
1298	}
1299	if (port->count) {
1300		spin_unlock_irqrestore(&port->lock, flags);
1301		goto done;
1302	}
1303
1304	/*
1305	 * Now we wait for the transmit buffer to clear; and we notify
1306	 * the line discipline to only process XON/XOFF characters by
1307	 * setting tty->closing.
1308	 */
1309	tty->closing = 1;
1310	spin_unlock_irqrestore(&port->lock, flags);
1311
1312	if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE) {
1313		/*
1314		 * hack: open-coded tty_wait_until_sent to avoid
1315		 * recursive tty_lock
1316		 */
1317		long timeout = msecs_to_jiffies(port->closing_wait);
1318		if (wait_event_interruptible_timeout(tty->write_wait,
1319				!tty_chars_in_buffer(tty), timeout) >= 0)
1320			__uart_wait_until_sent(uport, timeout);
1321	}
1322
1323	/*
1324	 * At this point, we stop accepting input.  To do this, we
1325	 * disable the receive line status interrupts.
1326	 */
1327	if (port->flags & ASYNC_INITIALIZED) {
1328		unsigned long flags;
1329		spin_lock_irqsave(&uport->lock, flags);
1330		uport->ops->stop_rx(uport);
1331		spin_unlock_irqrestore(&uport->lock, flags);
1332		/*
1333		 * Before we drop DTR, make sure the UART transmitter
1334		 * has completely drained; this is especially
1335		 * important if there is a transmit FIFO!
1336		 */
1337		__uart_wait_until_sent(uport, uport->timeout);
1338	}
1339
 
1340	uart_shutdown(tty, state);
1341	uart_flush_buffer(tty);
1342
1343	tty_ldisc_flush(tty);
1344
1345	tty_port_tty_set(port, NULL);
1346	spin_lock_irqsave(&port->lock, flags);
1347	tty->closing = 0;
1348
1349	if (port->blocked_open) {
1350		spin_unlock_irqrestore(&port->lock, flags);
1351		if (port->close_delay)
1352			msleep_interruptible(port->close_delay);
 
1353		spin_lock_irqsave(&port->lock, flags);
1354	} else if (!uart_console(uport)) {
1355		spin_unlock_irqrestore(&port->lock, flags);
1356		uart_change_pm(state, 3);
1357		spin_lock_irqsave(&port->lock, flags);
1358	}
1359
1360	/*
1361	 * Wake up anyone trying to open this port.
1362	 */
1363	clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
 
1364	spin_unlock_irqrestore(&port->lock, flags);
1365	wake_up_interruptible(&port->open_wait);
 
1366
1367done:
1368	mutex_unlock(&port->mutex);
1369}
1370
1371static void __uart_wait_until_sent(struct uart_port *port, int timeout)
1372{
 
 
1373	unsigned long char_time, expire;
1374
1375	if (port->type == PORT_UNKNOWN || port->fifosize == 0)
1376		return;
1377
1378	/*
1379	 * Set the check interval to be 1/5 of the estimated time to
1380	 * send a single character, and make it at least 1.  The check
1381	 * interval should also be less than the timeout.
1382	 *
1383	 * Note: we have to use pretty tight timings here to satisfy
1384	 * the NIST-PCTS.
1385	 */
1386	char_time = (port->timeout - HZ/50) / port->fifosize;
1387	char_time = char_time / 5;
1388	if (char_time == 0)
1389		char_time = 1;
1390	if (timeout && timeout < char_time)
1391		char_time = timeout;
1392
1393	/*
1394	 * If the transmitter hasn't cleared in twice the approximate
1395	 * amount of time to send the entire FIFO, it probably won't
1396	 * ever clear.  This assumes the UART isn't doing flow
1397	 * control, which is currently the case.  Hence, if it ever
1398	 * takes longer than port->timeout, this is probably due to a
1399	 * UART bug of some kind.  So, we clamp the timeout parameter at
1400	 * 2*port->timeout.
1401	 */
1402	if (timeout == 0 || timeout > 2 * port->timeout)
1403		timeout = 2 * port->timeout;
1404
1405	expire = jiffies + timeout;
1406
1407	pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1408		port->line, jiffies, expire);
1409
1410	/*
1411	 * Check whether the transmitter is empty every 'char_time'.
1412	 * 'timeout' / 'expire' give us the maximum amount of time
1413	 * we wait.
1414	 */
1415	while (!port->ops->tx_empty(port)) {
1416		msleep_interruptible(jiffies_to_msecs(char_time));
1417		if (signal_pending(current))
1418			break;
1419		if (time_after(jiffies, expire))
1420			break;
1421	}
1422}
1423
1424static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1425{
1426	struct uart_state *state = tty->driver_data;
1427	struct uart_port *port = state->uart_port;
1428
1429	tty_lock();
1430	__uart_wait_until_sent(port, timeout);
1431	tty_unlock();
1432}
1433
1434/*
1435 * This is called with the BKL held in
1436 *  linux/drivers/char/tty_io.c:do_tty_hangup()
1437 * We're called from the eventd thread, so we can sleep for
1438 * a _short_ time only.
1439 */
1440static void uart_hangup(struct tty_struct *tty)
1441{
1442	struct uart_state *state = tty->driver_data;
1443	struct tty_port *port = &state->port;
1444	unsigned long flags;
1445
1446	BUG_ON(!tty_locked());
1447	pr_debug("uart_hangup(%d)\n", state->uart_port->line);
1448
1449	mutex_lock(&port->mutex);
1450	if (port->flags & ASYNC_NORMAL_ACTIVE) {
1451		uart_flush_buffer(tty);
1452		uart_shutdown(tty, state);
1453		spin_lock_irqsave(&port->lock, flags);
1454		port->count = 0;
1455		clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1456		spin_unlock_irqrestore(&port->lock, flags);
1457		tty_port_tty_set(port, NULL);
1458		wake_up_interruptible(&port->open_wait);
1459		wake_up_interruptible(&port->delta_msr_wait);
1460	}
1461	mutex_unlock(&port->mutex);
1462}
1463
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1464static int uart_carrier_raised(struct tty_port *port)
1465{
1466	struct uart_state *state = container_of(port, struct uart_state, port);
1467	struct uart_port *uport = state->uart_port;
1468	int mctrl;
1469	spin_lock_irq(&uport->lock);
1470	uport->ops->enable_ms(uport);
1471	mctrl = uport->ops->get_mctrl(uport);
1472	spin_unlock_irq(&uport->lock);
1473	if (mctrl & TIOCM_CAR)
1474		return 1;
1475	return 0;
1476}
1477
1478static void uart_dtr_rts(struct tty_port *port, int onoff)
1479{
1480	struct uart_state *state = container_of(port, struct uart_state, port);
1481	struct uart_port *uport = state->uart_port;
1482
1483	if (onoff)
1484		uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1485	else
1486		uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1487}
1488
1489static struct uart_state *uart_get(struct uart_driver *drv, int line)
1490{
1491	struct uart_state *state;
1492	struct tty_port *port;
1493	int ret = 0;
1494
1495	state = drv->state + line;
1496	port = &state->port;
1497	if (mutex_lock_interruptible(&port->mutex)) {
1498		ret = -ERESTARTSYS;
1499		goto err;
1500	}
1501
1502	port->count++;
1503	if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1504		ret = -ENXIO;
1505		goto err_unlock;
1506	}
1507	return state;
1508
1509 err_unlock:
1510	port->count--;
1511	mutex_unlock(&port->mutex);
1512 err:
1513	return ERR_PTR(ret);
1514}
1515
1516/*
1517 * calls to uart_open are serialised by the BKL in
1518 *   fs/char_dev.c:chrdev_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	struct uart_state *state;
1530	struct tty_port *port;
1531	int retval, line = tty->index;
 
 
1532
1533	BUG_ON(!tty_locked());
1534	pr_debug("uart_open(%d) called\n", line);
1535
1536	/*
1537	 * We take the semaphore inside uart_get to guarantee that we won't
1538	 * be re-entered while allocating the state structure, or while we
1539	 * request any IRQs that the driver may need.  This also has the nice
1540	 * side-effect that it delays the action of uart_hangup, so we can
1541	 * guarantee that state->port.tty will always contain something
1542	 * reasonable.
1543	 */
1544	state = uart_get(drv, line);
1545	if (IS_ERR(state)) {
1546		retval = PTR_ERR(state);
1547		goto fail;
 
 
 
 
1548	}
1549	port = &state->port;
1550
1551	/*
1552	 * Once we set tty->driver_data here, we are guaranteed that
1553	 * uart_close() will decrement the driver module use count.
1554	 * Any failures from here onwards should not touch the count.
1555	 */
1556	tty->driver_data = state;
1557	state->uart_port->state = state;
1558	tty->low_latency = (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1559	tty->alt_speed = 0;
1560	tty_port_tty_set(port, tty);
1561
1562	/*
1563	 * If the port is in the middle of closing, bail out now.
1564	 */
1565	if (tty_hung_up_p(filp)) {
1566		retval = -EAGAIN;
1567		port->count--;
1568		mutex_unlock(&port->mutex);
1569		goto fail;
1570	}
1571
1572	/*
1573	 * Make sure the device is in D0 state.
1574	 */
1575	if (port->count == 1)
1576		uart_change_pm(state, 0);
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
1590fail:
1591	return retval;
 
 
 
 
1592}
1593
1594static const char *uart_type(struct uart_port *port)
1595{
1596	const char *str = NULL;
1597
1598	if (port->ops->type)
1599		str = port->ops->type(port);
1600
1601	if (!str)
1602		str = "unknown";
1603
1604	return str;
1605}
1606
1607#ifdef CONFIG_PROC_FS
1608
1609static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1610{
1611	struct uart_state *state = drv->state + i;
1612	struct tty_port *port = &state->port;
1613	int pm_state;
1614	struct uart_port *uport = state->uart_port;
1615	char stat_buf[32];
1616	unsigned int status;
1617	int mmio;
1618
1619	if (!uport)
1620		return;
1621
1622	mmio = uport->iotype >= UPIO_MEM;
1623	seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1624			uport->line, uart_type(uport),
1625			mmio ? "mmio:0x" : "port:",
1626			mmio ? (unsigned long long)uport->mapbase
1627			     : (unsigned long long)uport->iobase,
1628			uport->irq);
1629
1630	if (uport->type == PORT_UNKNOWN) {
1631		seq_putc(m, '\n');
1632		return;
1633	}
1634
1635	if (capable(CAP_SYS_ADMIN)) {
1636		mutex_lock(&port->mutex);
1637		pm_state = state->pm_state;
1638		if (pm_state)
1639			uart_change_pm(state, 0);
1640		spin_lock_irq(&uport->lock);
1641		status = uport->ops->get_mctrl(uport);
1642		spin_unlock_irq(&uport->lock);
1643		if (pm_state)
1644			uart_change_pm(state, pm_state);
1645		mutex_unlock(&port->mutex);
1646
1647		seq_printf(m, " tx:%d rx:%d",
1648				uport->icount.tx, uport->icount.rx);
1649		if (uport->icount.frame)
1650			seq_printf(m, " fe:%d",
1651				uport->icount.frame);
1652		if (uport->icount.parity)
1653			seq_printf(m, " pe:%d",
1654				uport->icount.parity);
1655		if (uport->icount.brk)
1656			seq_printf(m, " brk:%d",
1657				uport->icount.brk);
1658		if (uport->icount.overrun)
1659			seq_printf(m, " oe:%d",
1660				uport->icount.overrun);
1661
1662#define INFOBIT(bit, str) \
1663	if (uport->mctrl & (bit)) \
1664		strncat(stat_buf, (str), sizeof(stat_buf) - \
1665			strlen(stat_buf) - 2)
1666#define STATBIT(bit, str) \
1667	if (status & (bit)) \
1668		strncat(stat_buf, (str), sizeof(stat_buf) - \
1669		       strlen(stat_buf) - 2)
1670
1671		stat_buf[0] = '\0';
1672		stat_buf[1] = '\0';
1673		INFOBIT(TIOCM_RTS, "|RTS");
1674		STATBIT(TIOCM_CTS, "|CTS");
1675		INFOBIT(TIOCM_DTR, "|DTR");
1676		STATBIT(TIOCM_DSR, "|DSR");
1677		STATBIT(TIOCM_CAR, "|CD");
1678		STATBIT(TIOCM_RNG, "|RI");
1679		if (stat_buf[0])
1680			stat_buf[0] = ' ';
1681
1682		seq_puts(m, stat_buf);
1683	}
1684	seq_putc(m, '\n');
1685#undef STATBIT
1686#undef INFOBIT
1687}
1688
1689static int uart_proc_show(struct seq_file *m, void *v)
1690{
1691	struct tty_driver *ttydrv = m->private;
1692	struct uart_driver *drv = ttydrv->driver_state;
1693	int i;
1694
1695	seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
1696			"", "", "");
1697	for (i = 0; i < drv->nr; i++)
1698		uart_line_info(m, drv, i);
1699	return 0;
1700}
1701
1702static int uart_proc_open(struct inode *inode, struct file *file)
1703{
1704	return single_open(file, uart_proc_show, PDE(inode)->data);
1705}
1706
1707static const struct file_operations uart_proc_fops = {
1708	.owner		= THIS_MODULE,
1709	.open		= uart_proc_open,
1710	.read		= seq_read,
1711	.llseek		= seq_lseek,
1712	.release	= single_release,
1713};
1714#endif
1715
1716#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1717/*
1718 *	uart_console_write - write a console message to a serial port
1719 *	@port: the port to write the message
1720 *	@s: array of characters
1721 *	@count: number of characters in string to write
1722 *	@write: function to write character to port
1723 */
1724void uart_console_write(struct uart_port *port, const char *s,
1725			unsigned int count,
1726			void (*putchar)(struct uart_port *, int))
1727{
1728	unsigned int i;
1729
1730	for (i = 0; i < count; i++, s++) {
1731		if (*s == '\n')
1732			putchar(port, '\r');
1733		putchar(port, *s);
1734	}
1735}
1736EXPORT_SYMBOL_GPL(uart_console_write);
1737
1738/*
1739 *	Check whether an invalid uart number has been specified, and
1740 *	if so, search for the first available port that does have
1741 *	console support.
1742 */
1743struct uart_port * __init
1744uart_get_console(struct uart_port *ports, int nr, struct console *co)
1745{
1746	int idx = co->index;
1747
1748	if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1749				     ports[idx].membase == NULL))
1750		for (idx = 0; idx < nr; idx++)
1751			if (ports[idx].iobase != 0 ||
1752			    ports[idx].membase != NULL)
1753				break;
1754
1755	co->index = idx;
1756
1757	return ports + idx;
1758}
1759
1760/**
1761 *	uart_parse_options - Parse serial port baud/parity/bits/flow contro.
1762 *	@options: pointer to option string
1763 *	@baud: pointer to an 'int' variable for the baud rate.
1764 *	@parity: pointer to an 'int' variable for the parity.
1765 *	@bits: pointer to an 'int' variable for the number of data bits.
1766 *	@flow: pointer to an 'int' variable for the flow control character.
1767 *
1768 *	uart_parse_options decodes a string containing the serial console
1769 *	options.  The format of the string is <baud><parity><bits><flow>,
1770 *	eg: 115200n8r
1771 */
1772void
1773uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
1774{
1775	char *s = options;
1776
1777	*baud = simple_strtoul(s, NULL, 10);
1778	while (*s >= '0' && *s <= '9')
1779		s++;
1780	if (*s)
1781		*parity = *s++;
1782	if (*s)
1783		*bits = *s++ - '0';
1784	if (*s)
1785		*flow = *s;
1786}
1787EXPORT_SYMBOL_GPL(uart_parse_options);
1788
1789struct baud_rates {
1790	unsigned int rate;
1791	unsigned int cflag;
1792};
1793
1794static const struct baud_rates baud_rates[] = {
1795	{ 921600, B921600 },
1796	{ 460800, B460800 },
1797	{ 230400, B230400 },
1798	{ 115200, B115200 },
1799	{  57600, B57600  },
1800	{  38400, B38400  },
1801	{  19200, B19200  },
1802	{   9600, B9600   },
1803	{   4800, B4800   },
1804	{   2400, B2400   },
1805	{   1200, B1200   },
1806	{      0, B38400  }
1807};
1808
1809/**
1810 *	uart_set_options - setup the serial console parameters
1811 *	@port: pointer to the serial ports uart_port structure
1812 *	@co: console pointer
1813 *	@baud: baud rate
1814 *	@parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1815 *	@bits: number of data bits
1816 *	@flow: flow control character - 'r' (rts)
1817 */
1818int
1819uart_set_options(struct uart_port *port, struct console *co,
1820		 int baud, int parity, int bits, int flow)
1821{
1822	struct ktermios termios;
1823	static struct ktermios dummy;
1824	int i;
1825
1826	/*
1827	 * Ensure that the serial console lock is initialised
1828	 * early.
1829	 */
1830	spin_lock_init(&port->lock);
1831	lockdep_set_class(&port->lock, &port_lock_key);
1832
1833	memset(&termios, 0, sizeof(struct ktermios));
1834
1835	termios.c_cflag = CREAD | HUPCL | CLOCAL;
1836
1837	/*
1838	 * Construct a cflag setting.
1839	 */
1840	for (i = 0; baud_rates[i].rate; i++)
1841		if (baud_rates[i].rate <= baud)
1842			break;
1843
1844	termios.c_cflag |= baud_rates[i].cflag;
1845
1846	if (bits == 7)
1847		termios.c_cflag |= CS7;
1848	else
1849		termios.c_cflag |= CS8;
1850
1851	switch (parity) {
1852	case 'o': case 'O':
1853		termios.c_cflag |= PARODD;
1854		/*fall through*/
1855	case 'e': case 'E':
1856		termios.c_cflag |= PARENB;
1857		break;
1858	}
1859
1860	if (flow == 'r')
1861		termios.c_cflag |= CRTSCTS;
1862
1863	/*
1864	 * some uarts on other side don't support no flow control.
1865	 * So we set * DTR in host uart to make them happy
1866	 */
1867	port->mctrl |= TIOCM_DTR;
1868
1869	port->ops->set_termios(port, &termios, &dummy);
1870	/*
1871	 * Allow the setting of the UART parameters with a NULL console
1872	 * too:
1873	 */
1874	if (co)
1875		co->cflag = termios.c_cflag;
1876
1877	return 0;
1878}
1879EXPORT_SYMBOL_GPL(uart_set_options);
1880#endif /* CONFIG_SERIAL_CORE_CONSOLE */
1881
 
 
 
 
 
 
 
 
1882static void uart_change_pm(struct uart_state *state, int pm_state)
1883{
1884	struct uart_port *port = state->uart_port;
1885
1886	if (state->pm_state != pm_state) {
1887		if (port->ops->pm)
1888			port->ops->pm(port, pm_state, state->pm_state);
1889		state->pm_state = pm_state;
1890	}
1891}
1892
1893struct uart_match {
1894	struct uart_port *port;
1895	struct uart_driver *driver;
1896};
1897
1898static int serial_match_port(struct device *dev, void *data)
1899{
1900	struct uart_match *match = data;
1901	struct tty_driver *tty_drv = match->driver->tty_driver;
1902	dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1903		match->port->line;
1904
1905	return dev->devt == devt; /* Actually, only one tty per port */
1906}
1907
1908int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1909{
1910	struct uart_state *state = drv->state + uport->line;
1911	struct tty_port *port = &state->port;
1912	struct device *tty_dev;
1913	struct uart_match match = {uport, drv};
1914
1915	mutex_lock(&port->mutex);
1916
1917	tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1918	if (device_may_wakeup(tty_dev)) {
1919		if (!enable_irq_wake(uport->irq))
1920			uport->irq_wake = 1;
1921		put_device(tty_dev);
1922		mutex_unlock(&port->mutex);
1923		return 0;
1924	}
1925	if (console_suspend_enabled || !uart_console(uport))
1926		uport->suspended = 1;
1927
1928	if (port->flags & ASYNC_INITIALIZED) {
1929		const struct uart_ops *ops = uport->ops;
1930		int tries;
1931
1932		if (console_suspend_enabled || !uart_console(uport)) {
1933			set_bit(ASYNCB_SUSPENDED, &port->flags);
1934			clear_bit(ASYNCB_INITIALIZED, &port->flags);
1935
1936			spin_lock_irq(&uport->lock);
1937			ops->stop_tx(uport);
1938			ops->set_mctrl(uport, 0);
1939			ops->stop_rx(uport);
1940			spin_unlock_irq(&uport->lock);
1941		}
1942
1943		/*
1944		 * Wait for the transmitter to empty.
1945		 */
1946		for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
1947			msleep(10);
1948		if (!tries)
1949			printk(KERN_ERR "%s%s%s%d: Unable to drain "
1950					"transmitter\n",
1951			       uport->dev ? dev_name(uport->dev) : "",
1952			       uport->dev ? ": " : "",
1953			       drv->dev_name,
1954			       drv->tty_driver->name_base + uport->line);
1955
1956		if (console_suspend_enabled || !uart_console(uport))
1957			ops->shutdown(uport);
1958	}
1959
1960	/*
1961	 * Disable the console device before suspending.
1962	 */
1963	if (console_suspend_enabled && uart_console(uport))
1964		console_stop(uport->cons);
1965
1966	if (console_suspend_enabled || !uart_console(uport))
1967		uart_change_pm(state, 3);
1968
1969	mutex_unlock(&port->mutex);
1970
1971	return 0;
1972}
1973
1974int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
1975{
1976	struct uart_state *state = drv->state + uport->line;
1977	struct tty_port *port = &state->port;
1978	struct device *tty_dev;
1979	struct uart_match match = {uport, drv};
1980	struct ktermios termios;
1981
1982	mutex_lock(&port->mutex);
1983
1984	tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1985	if (!uport->suspended && device_may_wakeup(tty_dev)) {
1986		if (uport->irq_wake) {
1987			disable_irq_wake(uport->irq);
1988			uport->irq_wake = 0;
1989		}
1990		mutex_unlock(&port->mutex);
1991		return 0;
1992	}
1993	uport->suspended = 0;
1994
1995	/*
1996	 * Re-enable the console device after suspending.
1997	 */
1998	if (uart_console(uport)) {
1999		/*
2000		 * First try to use the console cflag setting.
2001		 */
2002		memset(&termios, 0, sizeof(struct ktermios));
2003		termios.c_cflag = uport->cons->cflag;
2004
2005		/*
2006		 * If that's unset, use the tty termios setting.
2007		 */
2008		if (port->tty && port->tty->termios && termios.c_cflag == 0)
2009			termios = *(port->tty->termios);
2010
 
 
2011		uport->ops->set_termios(uport, &termios, NULL);
2012		if (console_suspend_enabled)
2013			console_start(uport->cons);
2014	}
2015
2016	if (port->flags & ASYNC_SUSPENDED) {
2017		const struct uart_ops *ops = uport->ops;
2018		int ret;
2019
2020		uart_change_pm(state, 0);
2021		spin_lock_irq(&uport->lock);
2022		ops->set_mctrl(uport, 0);
2023		spin_unlock_irq(&uport->lock);
2024		if (console_suspend_enabled || !uart_console(uport)) {
2025			/* Protected by port mutex for now */
2026			struct tty_struct *tty = port->tty;
2027			ret = ops->startup(uport);
2028			if (ret == 0) {
2029				if (tty)
2030					uart_change_speed(tty, state, NULL);
2031				spin_lock_irq(&uport->lock);
2032				ops->set_mctrl(uport, uport->mctrl);
2033				ops->start_tx(uport);
2034				spin_unlock_irq(&uport->lock);
2035				set_bit(ASYNCB_INITIALIZED, &port->flags);
2036			} else {
2037				/*
2038				 * Failed to resume - maybe hardware went away?
2039				 * Clear the "initialized" flag so we won't try
2040				 * to call the low level drivers shutdown method.
2041				 */
2042				uart_shutdown(tty, state);
2043			}
2044		}
2045
2046		clear_bit(ASYNCB_SUSPENDED, &port->flags);
2047	}
2048
2049	mutex_unlock(&port->mutex);
2050
2051	return 0;
2052}
2053
2054static inline void
2055uart_report_port(struct uart_driver *drv, struct uart_port *port)
2056{
2057	char address[64];
2058
2059	switch (port->iotype) {
2060	case UPIO_PORT:
2061		snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2062		break;
2063	case UPIO_HUB6:
2064		snprintf(address, sizeof(address),
2065			 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2066		break;
2067	case UPIO_MEM:
2068	case UPIO_MEM32:
2069	case UPIO_AU:
2070	case UPIO_TSI:
2071	case UPIO_DWAPB:
2072	case UPIO_DWAPB32:
2073		snprintf(address, sizeof(address),
2074			 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2075		break;
2076	default:
2077		strlcpy(address, "*unknown*", sizeof(address));
2078		break;
2079	}
2080
2081	printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
2082	       port->dev ? dev_name(port->dev) : "",
2083	       port->dev ? ": " : "",
2084	       drv->dev_name,
2085	       drv->tty_driver->name_base + port->line,
2086	       address, port->irq, uart_type(port));
2087}
2088
2089static void
2090uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2091		    struct uart_port *port)
2092{
2093	unsigned int flags;
2094
2095	/*
2096	 * If there isn't a port here, don't do anything further.
2097	 */
2098	if (!port->iobase && !port->mapbase && !port->membase)
2099		return;
2100
2101	/*
2102	 * Now do the auto configuration stuff.  Note that config_port
2103	 * is expected to claim the resources and map the port for us.
2104	 */
2105	flags = 0;
2106	if (port->flags & UPF_AUTO_IRQ)
2107		flags |= UART_CONFIG_IRQ;
2108	if (port->flags & UPF_BOOT_AUTOCONF) {
2109		if (!(port->flags & UPF_FIXED_TYPE)) {
2110			port->type = PORT_UNKNOWN;
2111			flags |= UART_CONFIG_TYPE;
2112		}
2113		port->ops->config_port(port, flags);
2114	}
2115
2116	if (port->type != PORT_UNKNOWN) {
2117		unsigned long flags;
2118
2119		uart_report_port(drv, port);
2120
2121		/* Power up port for set_mctrl() */
2122		uart_change_pm(state, 0);
2123
2124		/*
2125		 * Ensure that the modem control lines are de-activated.
2126		 * keep the DTR setting that is set in uart_set_options()
2127		 * We probably don't need a spinlock around this, but
2128		 */
2129		spin_lock_irqsave(&port->lock, flags);
2130		port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2131		spin_unlock_irqrestore(&port->lock, flags);
2132
2133		/*
2134		 * If this driver supports console, and it hasn't been
2135		 * successfully registered yet, try to re-register it.
2136		 * It may be that the port was not available.
2137		 */
2138		if (port->cons && !(port->cons->flags & CON_ENABLED))
2139			register_console(port->cons);
2140
2141		/*
2142		 * Power down all ports by default, except the
2143		 * console if we have one.
2144		 */
2145		if (!uart_console(port))
2146			uart_change_pm(state, 3);
2147	}
2148}
2149
2150#ifdef CONFIG_CONSOLE_POLL
2151
2152static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2153{
2154	struct uart_driver *drv = driver->driver_state;
2155	struct uart_state *state = drv->state + line;
2156	struct uart_port *port;
2157	int baud = 9600;
2158	int bits = 8;
2159	int parity = 'n';
2160	int flow = 'n';
2161
2162	if (!state || !state->uart_port)
2163		return -1;
2164
2165	port = state->uart_port;
2166	if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2167		return -1;
2168
2169	if (options) {
2170		uart_parse_options(options, &baud, &parity, &bits, &flow);
2171		return uart_set_options(port, NULL, baud, parity, bits, flow);
2172	}
2173
2174	return 0;
2175}
2176
2177static int uart_poll_get_char(struct tty_driver *driver, int line)
2178{
2179	struct uart_driver *drv = driver->driver_state;
2180	struct uart_state *state = drv->state + line;
2181	struct uart_port *port;
2182
2183	if (!state || !state->uart_port)
2184		return -1;
2185
2186	port = state->uart_port;
2187	return port->ops->poll_get_char(port);
2188}
2189
2190static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2191{
2192	struct uart_driver *drv = driver->driver_state;
2193	struct uart_state *state = drv->state + line;
2194	struct uart_port *port;
2195
2196	if (!state || !state->uart_port)
2197		return;
2198
2199	port = state->uart_port;
2200	port->ops->poll_put_char(port, ch);
2201}
2202#endif
2203
2204static const struct tty_operations uart_ops = {
2205	.open		= uart_open,
2206	.close		= uart_close,
2207	.write		= uart_write,
2208	.put_char	= uart_put_char,
2209	.flush_chars	= uart_flush_chars,
2210	.write_room	= uart_write_room,
2211	.chars_in_buffer= uart_chars_in_buffer,
2212	.flush_buffer	= uart_flush_buffer,
2213	.ioctl		= uart_ioctl,
2214	.throttle	= uart_throttle,
2215	.unthrottle	= uart_unthrottle,
2216	.send_xchar	= uart_send_xchar,
2217	.set_termios	= uart_set_termios,
2218	.set_ldisc	= uart_set_ldisc,
2219	.stop		= uart_stop,
2220	.start		= uart_start,
2221	.hangup		= uart_hangup,
2222	.break_ctl	= uart_break_ctl,
2223	.wait_until_sent= uart_wait_until_sent,
2224#ifdef CONFIG_PROC_FS
2225	.proc_fops	= &uart_proc_fops,
2226#endif
2227	.tiocmget	= uart_tiocmget,
2228	.tiocmset	= uart_tiocmset,
2229	.get_icount	= uart_get_icount,
2230#ifdef CONFIG_CONSOLE_POLL
2231	.poll_init	= uart_poll_init,
2232	.poll_get_char	= uart_poll_get_char,
2233	.poll_put_char	= uart_poll_put_char,
2234#endif
2235};
2236
2237static const struct tty_port_operations uart_port_ops = {
 
 
2238	.carrier_raised = uart_carrier_raised,
2239	.dtr_rts	= uart_dtr_rts,
2240};
2241
2242/**
2243 *	uart_register_driver - register a driver with the uart core layer
2244 *	@drv: low level driver structure
2245 *
2246 *	Register a uart driver with the core driver.  We in turn register
2247 *	with the tty layer, and initialise the core driver per-port state.
2248 *
2249 *	We have a proc file in /proc/tty/driver which is named after the
2250 *	normal driver.
2251 *
2252 *	drv->port should be NULL, and the per-port structures should be
2253 *	registered using uart_add_one_port after this call has succeeded.
2254 */
2255int uart_register_driver(struct uart_driver *drv)
2256{
2257	struct tty_driver *normal;
2258	int i, retval;
2259
2260	BUG_ON(drv->state);
2261
2262	/*
2263	 * Maybe we should be using a slab cache for this, especially if
2264	 * we have a large number of ports to handle.
2265	 */
2266	drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2267	if (!drv->state)
2268		goto out;
2269
2270	normal = alloc_tty_driver(drv->nr);
2271	if (!normal)
2272		goto out_kfree;
2273
2274	drv->tty_driver = normal;
2275
2276	normal->owner		= drv->owner;
2277	normal->driver_name	= drv->driver_name;
2278	normal->name		= drv->dev_name;
2279	normal->major		= drv->major;
2280	normal->minor_start	= drv->minor;
2281	normal->type		= TTY_DRIVER_TYPE_SERIAL;
2282	normal->subtype		= SERIAL_TYPE_NORMAL;
2283	normal->init_termios	= tty_std_termios;
2284	normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2285	normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2286	normal->flags		= TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2287	normal->driver_state    = drv;
2288	tty_set_operations(normal, &uart_ops);
2289
2290	/*
2291	 * Initialise the UART state(s).
2292	 */
2293	for (i = 0; i < drv->nr; i++) {
2294		struct uart_state *state = drv->state + i;
2295		struct tty_port *port = &state->port;
2296
2297		tty_port_init(port);
2298		port->ops = &uart_port_ops;
2299		port->close_delay     = 500;	/* .5 seconds */
2300		port->closing_wait    = 30000;	/* 30 seconds */
2301		tasklet_init(&state->tlet, uart_tasklet_action,
2302			     (unsigned long)state);
2303	}
2304
2305	retval = tty_register_driver(normal);
2306	if (retval >= 0)
2307		return retval;
2308
2309	put_tty_driver(normal);
2310out_kfree:
2311	kfree(drv->state);
2312out:
2313	return -ENOMEM;
2314}
2315
2316/**
2317 *	uart_unregister_driver - remove a driver from the uart core layer
2318 *	@drv: low level driver structure
2319 *
2320 *	Remove all references to a driver from the core driver.  The low
2321 *	level driver must have removed all its ports via the
2322 *	uart_remove_one_port() if it registered them with uart_add_one_port().
2323 *	(ie, drv->port == NULL)
2324 */
2325void uart_unregister_driver(struct uart_driver *drv)
2326{
2327	struct tty_driver *p = drv->tty_driver;
2328	tty_unregister_driver(p);
2329	put_tty_driver(p);
2330	kfree(drv->state);
 
2331	drv->tty_driver = NULL;
2332}
2333
2334struct tty_driver *uart_console_device(struct console *co, int *index)
2335{
2336	struct uart_driver *p = co->data;
2337	*index = co->index;
2338	return p->tty_driver;
2339}
2340
2341/**
2342 *	uart_add_one_port - attach a driver-defined port structure
2343 *	@drv: pointer to the uart low level driver structure for this port
2344 *	@uport: uart port structure to use for this port.
2345 *
2346 *	This allows the driver to register its own uart_port structure
2347 *	with the core driver.  The main purpose is to allow the low
2348 *	level uart drivers to expand uart_port, rather than having yet
2349 *	more levels of structures.
2350 */
2351int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2352{
2353	struct uart_state *state;
2354	struct tty_port *port;
2355	int ret = 0;
2356	struct device *tty_dev;
2357
2358	BUG_ON(in_interrupt());
2359
2360	if (uport->line >= drv->nr)
2361		return -EINVAL;
2362
2363	state = drv->state + uport->line;
2364	port = &state->port;
2365
2366	mutex_lock(&port_mutex);
2367	mutex_lock(&port->mutex);
2368	if (state->uart_port) {
2369		ret = -EINVAL;
2370		goto out;
2371	}
2372
2373	state->uart_port = uport;
2374	state->pm_state = -1;
2375
2376	uport->cons = drv->cons;
2377	uport->state = state;
2378
2379	/*
2380	 * If this port is a console, then the spinlock is already
2381	 * initialised.
2382	 */
2383	if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2384		spin_lock_init(&uport->lock);
2385		lockdep_set_class(&uport->lock, &port_lock_key);
2386	}
2387
2388	uart_configure_port(drv, state, uport);
2389
2390	/*
2391	 * Register the port whether it's detected or not.  This allows
2392	 * setserial to be used to alter this ports parameters.
2393	 */
2394	tty_dev = tty_register_device(drv->tty_driver, uport->line, uport->dev);
2395	if (likely(!IS_ERR(tty_dev))) {
2396		device_init_wakeup(tty_dev, 1);
2397		device_set_wakeup_enable(tty_dev, 0);
2398	} else
2399		printk(KERN_ERR "Cannot register tty device on line %d\n",
2400		       uport->line);
 
2401
2402	/*
2403	 * Ensure UPF_DEAD is not set.
2404	 */
2405	uport->flags &= ~UPF_DEAD;
2406
2407 out:
2408	mutex_unlock(&port->mutex);
2409	mutex_unlock(&port_mutex);
2410
2411	return ret;
2412}
2413
2414/**
2415 *	uart_remove_one_port - detach a driver defined port structure
2416 *	@drv: pointer to the uart low level driver structure for this port
2417 *	@uport: uart port structure for this port
2418 *
2419 *	This unhooks (and hangs up) the specified port structure from the
2420 *	core driver.  No further calls will be made to the low-level code
2421 *	for this port.
2422 */
2423int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2424{
2425	struct uart_state *state = drv->state + uport->line;
2426	struct tty_port *port = &state->port;
2427
2428	BUG_ON(in_interrupt());
2429
2430	if (state->uart_port != uport)
2431		printk(KERN_ALERT "Removing wrong port: %p != %p\n",
2432			state->uart_port, uport);
2433
2434	mutex_lock(&port_mutex);
2435
2436	/*
2437	 * Mark the port "dead" - this prevents any opens from
2438	 * succeeding while we shut down the port.
2439	 */
2440	mutex_lock(&port->mutex);
2441	uport->flags |= UPF_DEAD;
2442	mutex_unlock(&port->mutex);
2443
2444	/*
2445	 * Remove the devices from the tty layer
2446	 */
2447	tty_unregister_device(drv->tty_driver, uport->line);
2448
2449	if (port->tty)
2450		tty_vhangup(port->tty);
2451
2452	/*
2453	 * Free the port IO and memory resources, if any.
2454	 */
2455	if (uport->type != PORT_UNKNOWN)
2456		uport->ops->release_port(uport);
2457
2458	/*
2459	 * Indicate that there isn't a port here anymore.
2460	 */
2461	uport->type = PORT_UNKNOWN;
2462
2463	/*
2464	 * Kill the tasklet, and free resources.
2465	 */
2466	tasklet_kill(&state->tlet);
2467
2468	state->uart_port = NULL;
2469	mutex_unlock(&port_mutex);
2470
2471	return 0;
2472}
2473
2474/*
2475 *	Are the two ports equivalent?
2476 */
2477int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2478{
2479	if (port1->iotype != port2->iotype)
2480		return 0;
2481
2482	switch (port1->iotype) {
2483	case UPIO_PORT:
2484		return (port1->iobase == port2->iobase);
2485	case UPIO_HUB6:
2486		return (port1->iobase == port2->iobase) &&
2487		       (port1->hub6   == port2->hub6);
2488	case UPIO_MEM:
2489	case UPIO_MEM32:
2490	case UPIO_AU:
2491	case UPIO_TSI:
2492	case UPIO_DWAPB:
2493	case UPIO_DWAPB32:
2494		return (port1->mapbase == port2->mapbase);
2495	}
2496	return 0;
2497}
2498EXPORT_SYMBOL(uart_match_port);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2499
2500EXPORT_SYMBOL(uart_write_wakeup);
2501EXPORT_SYMBOL(uart_register_driver);
2502EXPORT_SYMBOL(uart_unregister_driver);
2503EXPORT_SYMBOL(uart_suspend_port);
2504EXPORT_SYMBOL(uart_resume_port);
2505EXPORT_SYMBOL(uart_add_one_port);
2506EXPORT_SYMBOL(uart_remove_one_port);
2507
2508MODULE_DESCRIPTION("Serial driver core");
2509MODULE_LICENSE("GPL");