1/*
   2 *  Driver core for serial ports
   3 *
   4 *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
   5 *
   6 *  Copyright 1999 ARM Limited
   7 *  Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License as published by
  11 * the Free Software Foundation; either version 2 of the License, or
  12 * (at your option) any later version.
  13 *
  14 * This program is distributed in the hope that it will be useful,
  15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 * GNU General Public License for more details.
  18 *
  19 * You should have received a copy of the GNU General Public License
  20 * along with this program; if not, write to the Free Software
  21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22 */
  23#include <linux/module.h>
  24#include <linux/tty.h>
  25#include <linux/tty_flip.h>
  26#include <linux/slab.h>
 
  27#include <linux/init.h>
  28#include <linux/console.h>
 
  29#include <linux/of.h>
  30#include <linux/proc_fs.h>
  31#include <linux/seq_file.h>
  32#include <linux/device.h>
  33#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
  34#include <linux/serial_core.h>
 
  35#include <linux/delay.h>
  36#include <linux/mutex.h>
 
  37
  38#include <asm/irq.h>
  39#include <asm/uaccess.h>
  40
  41/*
  42 * This is used to lock changes in serial line configuration.
  43 */
  44static DEFINE_MUTEX(port_mutex);
  45
  46/*
  47 * lockdep: port->lock is initialized in two places, but we
  48 *          want only one lock-class:
  49 */
  50static struct lock_class_key port_lock_key;
  51
  52#define HIGH_BITS_OFFSET	((sizeof(long)-sizeof(int))*8)
  53
  54static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
  55					struct ktermios *old_termios);
  56static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
  57static void uart_change_pm(struct uart_state *state,
  58			   enum uart_pm_state pm_state);
  59
  60static void uart_port_shutdown(struct tty_port *port);
  61
  62static int uart_dcd_enabled(struct uart_port *uport)
  63{
  64	return !!(uport->status & UPSTAT_DCD_ENABLE);
  65}
  66
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  67/*
  68 * This routine is used by the interrupt handler to schedule processing in
  69 * the software interrupt portion of the driver.
  70 */
  71void uart_write_wakeup(struct uart_port *port)
  72{
  73	struct uart_state *state = port->state;
  74	/*
  75	 * This means you called this function _after_ the port was
  76	 * closed.  No cookie for you.
  77	 */
  78	BUG_ON(!state);
  79	tty_wakeup(state->port.tty);
  80}
  81
  82static void uart_stop(struct tty_struct *tty)
  83{
  84	struct uart_state *state = tty->driver_data;
  85	struct uart_port *port = state->uart_port;
  86	unsigned long flags;
  87
  88	spin_lock_irqsave(&port->lock, flags);
  89	port->ops->stop_tx(port);
  90	spin_unlock_irqrestore(&port->lock, flags);
 
  91}
  92
  93static void __uart_start(struct tty_struct *tty)
  94{
  95	struct uart_state *state = tty->driver_data;
  96	struct uart_port *port = state->uart_port;
  97
  98	if (!uart_tx_stopped(port))
  99		port->ops->start_tx(port);
 100}
 101
 102static void uart_start(struct tty_struct *tty)
 103{
 104	struct uart_state *state = tty->driver_data;
 105	struct uart_port *port = state->uart_port;
 106	unsigned long flags;
 107
 108	spin_lock_irqsave(&port->lock, flags);
 109	__uart_start(tty);
 110	spin_unlock_irqrestore(&port->lock, flags);
 111}
 112
 113static void
 114uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
 115{
 116	unsigned long flags;
 117	unsigned int old;
 118
 119	spin_lock_irqsave(&port->lock, flags);
 120	old = port->mctrl;
 121	port->mctrl = (old & ~clear) | set;
 122	if (old != port->mctrl)
 123		port->ops->set_mctrl(port, port->mctrl);
 124	spin_unlock_irqrestore(&port->lock, flags);
 125}
 126
 127#define uart_set_mctrl(port, set)	uart_update_mctrl(port, set, 0)
 128#define uart_clear_mctrl(port, clear)	uart_update_mctrl(port, 0, clear)
 129
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 130/*
 131 * Startup the port.  This will be called once per open.  All calls
 132 * will be serialised by the per-port mutex.
 133 */
 134static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
 135		int init_hw)
 136{
 137	struct uart_port *uport = state->uart_port;
 138	unsigned long page;
 
 139	int retval = 0;
 140
 141	if (uport->type == PORT_UNKNOWN)
 142		return 1;
 143
 144	/*
 145	 * Make sure the device is in D0 state.
 146	 */
 147	uart_change_pm(state, UART_PM_STATE_ON);
 148
 149	/*
 150	 * Initialise and allocate the transmit and temporary
 151	 * buffer.
 152	 */
 153	if (!state->xmit.buf) {
 154		/* This is protected by the per port mutex */
 155		page = get_zeroed_page(GFP_KERNEL);
 156		if (!page)
 157			return -ENOMEM;
 158
 
 
 159		state->xmit.buf = (unsigned char *) page;
 160		uart_circ_clear(&state->xmit);
 
 
 
 
 
 
 
 
 161	}
 162
 163	retval = uport->ops->startup(uport);
 164	if (retval == 0) {
 165		if (uart_console(uport) && uport->cons->cflag) {
 166			tty->termios.c_cflag = uport->cons->cflag;
 167			uport->cons->cflag = 0;
 168		}
 169		/*
 170		 * Initialise the hardware port settings.
 171		 */
 172		uart_change_speed(tty, state, NULL);
 173
 174		/*
 175		 * Setup the RTS and DTR signals once the
 176		 * port is open and ready to respond.
 177		 */
 178		if (init_hw && C_BAUD(tty))
 179			uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
 180	}
 181
 182	/*
 183	 * This is to allow setserial on this port. People may want to set
 184	 * port/irq/type and then reconfigure the port properly if it failed
 185	 * now.
 186	 */
 187	if (retval && capable(CAP_SYS_ADMIN))
 188		return 1;
 189
 190	return retval;
 191}
 192
 193static int uart_startup(struct tty_struct *tty, struct uart_state *state,
 194		int init_hw)
 195{
 196	struct tty_port *port = &state->port;
 197	int retval;
 198
 199	if (port->flags & ASYNC_INITIALIZED)
 200		return 0;
 201
 202	/*
 203	 * Set the TTY IO error marker - we will only clear this
 204	 * once we have successfully opened the port.
 205	 */
 206	set_bit(TTY_IO_ERROR, &tty->flags);
 207
 208	retval = uart_port_startup(tty, state, init_hw);
 209	if (!retval) {
 210		set_bit(ASYNCB_INITIALIZED, &port->flags);
 211		clear_bit(TTY_IO_ERROR, &tty->flags);
 212	} else if (retval > 0)
 213		retval = 0;
 214
 215	return retval;
 216}
 217
 218/*
 219 * This routine will shutdown a serial port; interrupts are disabled, and
 220 * DTR is dropped if the hangup on close termio flag is on.  Calls to
 221 * uart_shutdown are serialised by the per-port semaphore.
 
 
 222 */
 223static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
 224{
 225	struct uart_port *uport = state->uart_port;
 226	struct tty_port *port = &state->port;
 
 
 227
 228	/*
 229	 * Set the TTY IO error marker
 230	 */
 231	if (tty)
 232		set_bit(TTY_IO_ERROR, &tty->flags);
 233
 234	if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) {
 
 
 235		/*
 236		 * Turn off DTR and RTS early.
 237		 */
 238		if (uart_console(uport) && tty)
 239			uport->cons->cflag = tty->termios.c_cflag;
 240
 241		if (!tty || C_HUPCL(tty))
 242			uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
 243
 244		uart_port_shutdown(port);
 245	}
 246
 247	/*
 248	 * It's possible for shutdown to be called after suspend if we get
 249	 * a DCD drop (hangup) at just the right time.  Clear suspended bit so
 250	 * we don't try to resume a port that has been shutdown.
 251	 */
 252	clear_bit(ASYNCB_SUSPENDED, &port->flags);
 253
 254	/*
 255	 * Free the transmit buffer page.
 
 
 
 256	 */
 257	if (state->xmit.buf) {
 258		free_page((unsigned long)state->xmit.buf);
 259		state->xmit.buf = NULL;
 260	}
 
 
 
 261}
 262
 263/**
 264 *	uart_update_timeout - update per-port FIFO timeout.
 265 *	@port:  uart_port structure describing the port
 266 *	@cflag: termios cflag value
 267 *	@baud:  speed of the port
 268 *
 269 *	Set the port FIFO timeout value.  The @cflag value should
 270 *	reflect the actual hardware settings.
 271 */
 272void
 273uart_update_timeout(struct uart_port *port, unsigned int cflag,
 274		    unsigned int baud)
 275{
 276	unsigned int bits;
 277
 278	/* byte size and parity */
 279	switch (cflag & CSIZE) {
 280	case CS5:
 281		bits = 7;
 282		break;
 283	case CS6:
 284		bits = 8;
 285		break;
 286	case CS7:
 287		bits = 9;
 288		break;
 289	default:
 290		bits = 10;
 291		break; /* CS8 */
 292	}
 293
 294	if (cflag & CSTOPB)
 295		bits++;
 296	if (cflag & PARENB)
 297		bits++;
 298
 299	/*
 300	 * The total number of bits to be transmitted in the fifo.
 301	 */
 302	bits = bits * port->fifosize;
 303
 304	/*
 305	 * Figure the timeout to send the above number of bits.
 306	 * Add .02 seconds of slop
 307	 */
 308	port->timeout = (HZ * bits) / baud + HZ/50;
 309}
 310
 311EXPORT_SYMBOL(uart_update_timeout);
 312
 313/**
 314 *	uart_get_baud_rate - return baud rate for a particular port
 315 *	@port: uart_port structure describing the port in question.
 316 *	@termios: desired termios settings.
 317 *	@old: old termios (or NULL)
 318 *	@min: minimum acceptable baud rate
 319 *	@max: maximum acceptable baud rate
 320 *
 321 *	Decode the termios structure into a numeric baud rate,
 322 *	taking account of the magic 38400 baud rate (with spd_*
 323 *	flags), and mapping the %B0 rate to 9600 baud.
 324 *
 325 *	If the new baud rate is invalid, try the old termios setting.
 326 *	If it's still invalid, we try 9600 baud.
 327 *
 328 *	Update the @termios structure to reflect the baud rate
 329 *	we're actually going to be using. Don't do this for the case
 330 *	where B0 is requested ("hang up").
 331 */
 332unsigned int
 333uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
 334		   struct ktermios *old, unsigned int min, unsigned int max)
 335{
 336	unsigned int try;
 337	unsigned int baud;
 338	unsigned int altbaud;
 339	int hung_up = 0;
 340	upf_t flags = port->flags & UPF_SPD_MASK;
 341
 342	switch (flags) {
 343	case UPF_SPD_HI:
 344		altbaud = 57600;
 345		break;
 346	case UPF_SPD_VHI:
 347		altbaud = 115200;
 348		break;
 349	case UPF_SPD_SHI:
 350		altbaud = 230400;
 351		break;
 352	case UPF_SPD_WARP:
 353		altbaud = 460800;
 354		break;
 355	default:
 356		altbaud = 38400;
 357		break;
 358	}
 359
 360	for (try = 0; try < 2; try++) {
 361		baud = tty_termios_baud_rate(termios);
 362
 363		/*
 364		 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
 365		 * Die! Die! Die!
 366		 */
 367		if (try == 0 && baud == 38400)
 368			baud = altbaud;
 369
 370		/*
 371		 * Special case: B0 rate.
 372		 */
 373		if (baud == 0) {
 374			hung_up = 1;
 375			baud = 9600;
 376		}
 377
 378		if (baud >= min && baud <= max)
 379			return baud;
 380
 381		/*
 382		 * Oops, the quotient was zero.  Try again with
 383		 * the old baud rate if possible.
 384		 */
 385		termios->c_cflag &= ~CBAUD;
 386		if (old) {
 387			baud = tty_termios_baud_rate(old);
 388			if (!hung_up)
 389				tty_termios_encode_baud_rate(termios,
 390								baud, baud);
 391			old = NULL;
 392			continue;
 393		}
 394
 395		/*
 396		 * As a last resort, if the range cannot be met then clip to
 397		 * the nearest chip supported rate.
 398		 */
 399		if (!hung_up) {
 400			if (baud <= min)
 401				tty_termios_encode_baud_rate(termios,
 402							min + 1, min + 1);
 403			else
 404				tty_termios_encode_baud_rate(termios,
 405							max - 1, max - 1);
 406		}
 407	}
 408	/* Should never happen */
 409	WARN_ON(1);
 410	return 0;
 411}
 412
 413EXPORT_SYMBOL(uart_get_baud_rate);
 414
 415/**
 416 *	uart_get_divisor - return uart clock divisor
 417 *	@port: uart_port structure describing the port.
 418 *	@baud: desired baud rate
 419 *
 420 *	Calculate the uart clock divisor for the port.
 421 */
 422unsigned int
 423uart_get_divisor(struct uart_port *port, unsigned int baud)
 424{
 425	unsigned int quot;
 426
 427	/*
 428	 * Old custom speed handling.
 429	 */
 430	if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
 431		quot = port->custom_divisor;
 432	else
 433		quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
 434
 435	return quot;
 436}
 437
 438EXPORT_SYMBOL(uart_get_divisor);
 439
 440/* Caller holds port mutex */
 441static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
 442					struct ktermios *old_termios)
 443{
 444	struct uart_port *uport = state->uart_port;
 445	struct ktermios *termios;
 446	int hw_stopped;
 447
 448	/*
 449	 * If we have no tty, termios, or the port does not exist,
 450	 * then we can't set the parameters for this port.
 451	 */
 452	if (!tty || uport->type == PORT_UNKNOWN)
 453		return;
 454
 455	termios = &tty->termios;
 456	uport->ops->set_termios(uport, termios, old_termios);
 457
 458	/*
 459	 * Set modem status enables based on termios cflag
 460	 */
 461	spin_lock_irq(&uport->lock);
 462	if (termios->c_cflag & CRTSCTS)
 463		uport->status |= UPSTAT_CTS_ENABLE;
 464	else
 465		uport->status &= ~UPSTAT_CTS_ENABLE;
 466
 467	if (termios->c_cflag & CLOCAL)
 468		uport->status &= ~UPSTAT_DCD_ENABLE;
 469	else
 470		uport->status |= UPSTAT_DCD_ENABLE;
 471
 472	/* reset sw-assisted CTS flow control based on (possibly) new mode */
 473	hw_stopped = uport->hw_stopped;
 474	uport->hw_stopped = uart_softcts_mode(uport) &&
 475				!(uport->ops->get_mctrl(uport) & TIOCM_CTS);
 476	if (uport->hw_stopped) {
 477		if (!hw_stopped)
 478			uport->ops->stop_tx(uport);
 479	} else {
 480		if (hw_stopped)
 481			__uart_start(tty);
 482	}
 483	spin_unlock_irq(&uport->lock);
 484}
 485
 486static int uart_put_char(struct tty_struct *tty, unsigned char c)
 487{
 488	struct uart_state *state = tty->driver_data;
 489	struct uart_port *port = state->uart_port;
 490	struct circ_buf *circ;
 491	unsigned long flags;
 492	int ret = 0;
 493
 494	circ = &state->xmit;
 495	if (!circ->buf)
 
 
 496		return 0;
 
 497
 498	spin_lock_irqsave(&port->lock, flags);
 499	if (uart_circ_chars_free(circ) != 0) {
 500		circ->buf[circ->head] = c;
 501		circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
 502		ret = 1;
 503	}
 504	spin_unlock_irqrestore(&port->lock, flags);
 505	return ret;
 506}
 507
 508static void uart_flush_chars(struct tty_struct *tty)
 509{
 510	uart_start(tty);
 511}
 512
 513static int uart_write(struct tty_struct *tty,
 514					const unsigned char *buf, int count)
 515{
 516	struct uart_state *state = tty->driver_data;
 517	struct uart_port *port;
 518	struct circ_buf *circ;
 519	unsigned long flags;
 520	int c, ret = 0;
 521
 522	/*
 523	 * This means you called this function _after_ the port was
 524	 * closed.  No cookie for you.
 525	 */
 526	if (!state) {
 527		WARN_ON(1);
 528		return -EL3HLT;
 529	}
 530
 531	port = state->uart_port;
 532	circ = &state->xmit;
 533
 534	if (!circ->buf)
 535		return 0;
 
 536
 537	spin_lock_irqsave(&port->lock, flags);
 538	while (1) {
 539		c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
 540		if (count < c)
 541			c = count;
 542		if (c <= 0)
 543			break;
 544		memcpy(circ->buf + circ->head, buf, c);
 545		circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
 546		buf += c;
 547		count -= c;
 548		ret += c;
 549	}
 550
 551	__uart_start(tty);
 552	spin_unlock_irqrestore(&port->lock, flags);
 553
 554	return ret;
 555}
 556
 557static int uart_write_room(struct tty_struct *tty)
 558{
 559	struct uart_state *state = tty->driver_data;
 
 560	unsigned long flags;
 561	int ret;
 562
 563	spin_lock_irqsave(&state->uart_port->lock, flags);
 564	ret = uart_circ_chars_free(&state->xmit);
 565	spin_unlock_irqrestore(&state->uart_port->lock, flags);
 566	return ret;
 567}
 568
 569static int uart_chars_in_buffer(struct tty_struct *tty)
 570{
 571	struct uart_state *state = tty->driver_data;
 
 572	unsigned long flags;
 573	int ret;
 574
 575	spin_lock_irqsave(&state->uart_port->lock, flags);
 576	ret = uart_circ_chars_pending(&state->xmit);
 577	spin_unlock_irqrestore(&state->uart_port->lock, flags);
 578	return ret;
 579}
 580
 581static void uart_flush_buffer(struct tty_struct *tty)
 582{
 583	struct uart_state *state = tty->driver_data;
 584	struct uart_port *port;
 585	unsigned long flags;
 586
 587	/*
 588	 * This means you called this function _after_ the port was
 589	 * closed.  No cookie for you.
 590	 */
 591	if (!state) {
 592		WARN_ON(1);
 593		return;
 594	}
 595
 596	port = state->uart_port;
 597	pr_debug("uart_flush_buffer(%d) called\n", tty->index);
 598
 599	spin_lock_irqsave(&port->lock, flags);
 
 
 600	uart_circ_clear(&state->xmit);
 601	if (port->ops->flush_buffer)
 602		port->ops->flush_buffer(port);
 603	spin_unlock_irqrestore(&port->lock, flags);
 604	tty_wakeup(tty);
 605}
 606
 607/*
 608 * This function is used to send a high-priority XON/XOFF character to
 609 * the device
 610 */
 611static void uart_send_xchar(struct tty_struct *tty, char ch)
 612{
 613	struct uart_state *state = tty->driver_data;
 614	struct uart_port *port = state->uart_port;
 615	unsigned long flags;
 616
 
 
 
 
 617	if (port->ops->send_xchar)
 618		port->ops->send_xchar(port, ch);
 619	else {
 620		spin_lock_irqsave(&port->lock, flags);
 621		port->x_char = ch;
 622		if (ch)
 623			port->ops->start_tx(port);
 624		spin_unlock_irqrestore(&port->lock, flags);
 625	}
 
 626}
 627
 628static void uart_throttle(struct tty_struct *tty)
 629{
 630	struct uart_state *state = tty->driver_data;
 631	struct uart_port *port = state->uart_port;
 632	upstat_t mask = 0;
 
 
 
 
 633
 634	if (I_IXOFF(tty))
 635		mask |= UPSTAT_AUTOXOFF;
 636	if (C_CRTSCTS(tty))
 637		mask |= UPSTAT_AUTORTS;
 638
 639	if (port->status & mask) {
 640		port->ops->throttle(port);
 641		mask &= ~port->status;
 642	}
 643
 644	if (mask & UPSTAT_AUTORTS)
 645		uart_clear_mctrl(port, TIOCM_RTS);
 646
 647	if (mask & UPSTAT_AUTOXOFF)
 648		uart_send_xchar(tty, STOP_CHAR(tty));
 
 
 649}
 650
 651static void uart_unthrottle(struct tty_struct *tty)
 652{
 653	struct uart_state *state = tty->driver_data;
 654	struct uart_port *port = state->uart_port;
 655	upstat_t mask = 0;
 
 
 
 
 656
 657	if (I_IXOFF(tty))
 658		mask |= UPSTAT_AUTOXOFF;
 659	if (C_CRTSCTS(tty))
 660		mask |= UPSTAT_AUTORTS;
 661
 662	if (port->status & mask) {
 663		port->ops->unthrottle(port);
 664		mask &= ~port->status;
 665	}
 666
 667	if (mask & UPSTAT_AUTORTS)
 668		uart_set_mctrl(port, TIOCM_RTS);
 669
 670	if (mask & UPSTAT_AUTOXOFF)
 671		uart_send_xchar(tty, START_CHAR(tty));
 
 
 672}
 673
 674static void uart_get_info(struct tty_port *port, struct serial_struct *retinfo)
 675{
 676	struct uart_state *state = container_of(port, struct uart_state, port);
 677	struct uart_port *uport = state->uart_port;
 
 678
 679	memset(retinfo, 0, sizeof(*retinfo));
 680
 681	/*
 682	 * Ensure the state we copy is consistent and no hardware changes
 683	 * occur as we go
 684	 */
 685	mutex_lock(&port->mutex);
 
 
 
 
 686	retinfo->type	    = uport->type;
 687	retinfo->line	    = uport->line;
 688	retinfo->port	    = uport->iobase;
 689	if (HIGH_BITS_OFFSET)
 690		retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
 691	retinfo->irq		    = uport->irq;
 692	retinfo->flags	    = uport->flags;
 693	retinfo->xmit_fifo_size  = uport->fifosize;
 694	retinfo->baud_base	    = uport->uartclk / 16;
 695	retinfo->close_delay	    = jiffies_to_msecs(port->close_delay) / 10;
 696	retinfo->closing_wait    = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
 697				ASYNC_CLOSING_WAIT_NONE :
 698				jiffies_to_msecs(port->closing_wait) / 10;
 699	retinfo->custom_divisor  = uport->custom_divisor;
 700	retinfo->hub6	    = uport->hub6;
 701	retinfo->io_type         = uport->iotype;
 702	retinfo->iomem_reg_shift = uport->regshift;
 703	retinfo->iomem_base      = (void *)(unsigned long)uport->mapbase;
 
 
 
 704	mutex_unlock(&port->mutex);
 
 705}
 706
 707static int uart_get_info_user(struct tty_port *port,
 708			 struct serial_struct __user *retinfo)
 709{
 710	struct serial_struct tmp;
 711
 712	uart_get_info(port, &tmp);
 713
 714	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
 715		return -EFAULT;
 716	return 0;
 717}
 718
 719static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
 720			 struct uart_state *state,
 721			 struct serial_struct *new_info)
 722{
 723	struct uart_port *uport = state->uart_port;
 724	unsigned long new_port;
 725	unsigned int change_irq, change_port, closing_wait;
 726	unsigned int old_custom_divisor, close_delay;
 727	upf_t old_flags, new_flags;
 728	int retval = 0;
 729
 
 
 
 730	new_port = new_info->port;
 731	if (HIGH_BITS_OFFSET)
 732		new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
 733
 734	new_info->irq = irq_canonicalize(new_info->irq);
 735	close_delay = msecs_to_jiffies(new_info->close_delay * 10);
 736	closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
 737			ASYNC_CLOSING_WAIT_NONE :
 738			msecs_to_jiffies(new_info->closing_wait * 10);
 739
 740
 741	change_irq  = !(uport->flags & UPF_FIXED_PORT)
 742		&& new_info->irq != uport->irq;
 743
 744	/*
 745	 * Since changing the 'type' of the port changes its resource
 746	 * allocations, we should treat type changes the same as
 747	 * IO port changes.
 748	 */
 749	change_port = !(uport->flags & UPF_FIXED_PORT)
 750		&& (new_port != uport->iobase ||
 751		    (unsigned long)new_info->iomem_base != uport->mapbase ||
 752		    new_info->hub6 != uport->hub6 ||
 753		    new_info->io_type != uport->iotype ||
 754		    new_info->iomem_reg_shift != uport->regshift ||
 755		    new_info->type != uport->type);
 756
 757	old_flags = uport->flags;
 758	new_flags = new_info->flags;
 759	old_custom_divisor = uport->custom_divisor;
 760
 761	if (!capable(CAP_SYS_ADMIN)) {
 762		retval = -EPERM;
 763		if (change_irq || change_port ||
 764		    (new_info->baud_base != uport->uartclk / 16) ||
 765		    (close_delay != port->close_delay) ||
 766		    (closing_wait != port->closing_wait) ||
 767		    (new_info->xmit_fifo_size &&
 768		     new_info->xmit_fifo_size != uport->fifosize) ||
 769		    (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
 770			goto exit;
 771		uport->flags = ((uport->flags & ~UPF_USR_MASK) |
 772			       (new_flags & UPF_USR_MASK));
 773		uport->custom_divisor = new_info->custom_divisor;
 774		goto check_and_exit;
 775	}
 776
 
 
 
 
 777	/*
 778	 * Ask the low level driver to verify the settings.
 779	 */
 780	if (uport->ops->verify_port)
 781		retval = uport->ops->verify_port(uport, new_info);
 782
 783	if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
 784	    (new_info->baud_base < 9600))
 785		retval = -EINVAL;
 786
 787	if (retval)
 788		goto exit;
 789
 790	if (change_port || change_irq) {
 791		retval = -EBUSY;
 792
 793		/*
 794		 * Make sure that we are the sole user of this port.
 795		 */
 796		if (tty_port_users(port) > 1)
 797			goto exit;
 798
 799		/*
 800		 * We need to shutdown the serial port at the old
 801		 * port/type/irq combination.
 802		 */
 803		uart_shutdown(tty, state);
 804	}
 805
 806	if (change_port) {
 807		unsigned long old_iobase, old_mapbase;
 808		unsigned int old_type, old_iotype, old_hub6, old_shift;
 809
 810		old_iobase = uport->iobase;
 811		old_mapbase = uport->mapbase;
 812		old_type = uport->type;
 813		old_hub6 = uport->hub6;
 814		old_iotype = uport->iotype;
 815		old_shift = uport->regshift;
 816
 817		/*
 818		 * Free and release old regions
 819		 */
 820		if (old_type != PORT_UNKNOWN)
 821			uport->ops->release_port(uport);
 822
 823		uport->iobase = new_port;
 824		uport->type = new_info->type;
 825		uport->hub6 = new_info->hub6;
 826		uport->iotype = new_info->io_type;
 827		uport->regshift = new_info->iomem_reg_shift;
 828		uport->mapbase = (unsigned long)new_info->iomem_base;
 829
 830		/*
 831		 * Claim and map the new regions
 832		 */
 833		if (uport->type != PORT_UNKNOWN) {
 834			retval = uport->ops->request_port(uport);
 835		} else {
 836			/* Always success - Jean II */
 837			retval = 0;
 838		}
 839
 840		/*
 841		 * If we fail to request resources for the
 842		 * new port, try to restore the old settings.
 843		 */
 844		if (retval) {
 845			uport->iobase = old_iobase;
 846			uport->type = old_type;
 847			uport->hub6 = old_hub6;
 848			uport->iotype = old_iotype;
 849			uport->regshift = old_shift;
 850			uport->mapbase = old_mapbase;
 851
 852			if (old_type != PORT_UNKNOWN) {
 853				retval = uport->ops->request_port(uport);
 854				/*
 855				 * If we failed to restore the old settings,
 856				 * we fail like this.
 857				 */
 858				if (retval)
 859					uport->type = PORT_UNKNOWN;
 860
 861				/*
 862				 * We failed anyway.
 863				 */
 864				retval = -EBUSY;
 865			}
 866
 867			/* Added to return the correct error -Ram Gupta */
 868			goto exit;
 869		}
 870	}
 871
 872	if (change_irq)
 873		uport->irq      = new_info->irq;
 874	if (!(uport->flags & UPF_FIXED_PORT))
 875		uport->uartclk  = new_info->baud_base * 16;
 876	uport->flags            = (uport->flags & ~UPF_CHANGE_MASK) |
 877				 (new_flags & UPF_CHANGE_MASK);
 878	uport->custom_divisor   = new_info->custom_divisor;
 879	port->close_delay     = close_delay;
 880	port->closing_wait    = closing_wait;
 881	if (new_info->xmit_fifo_size)
 882		uport->fifosize = new_info->xmit_fifo_size;
 883	port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
 884
 885 check_and_exit:
 886	retval = 0;
 887	if (uport->type == PORT_UNKNOWN)
 888		goto exit;
 889	if (port->flags & ASYNC_INITIALIZED) {
 890		if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
 891		    old_custom_divisor != uport->custom_divisor) {
 892			/*
 893			 * If they're setting up a custom divisor or speed,
 894			 * instead of clearing it, then bitch about it. No
 895			 * need to rate-limit; it's CAP_SYS_ADMIN only.
 896			 */
 897			if (uport->flags & UPF_SPD_MASK) {
 898				dev_notice(uport->dev,
 899				       "%s sets custom speed on %s. This is deprecated.\n",
 900				      current->comm,
 901				      tty_name(port->tty));
 902			}
 903			uart_change_speed(tty, state, NULL);
 904		}
 905	} else
 906		retval = uart_startup(tty, state, 1);
 
 
 
 
 
 907 exit:
 908	return retval;
 909}
 910
 911static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state,
 912			 struct serial_struct __user *newinfo)
 913{
 914	struct serial_struct new_serial;
 915	struct tty_port *port = &state->port;
 916	int retval;
 917
 918	if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
 919		return -EFAULT;
 920
 921	/*
 922	 * This semaphore protects port->count.  It is also
 923	 * very useful to prevent opens.  Also, take the
 924	 * port configuration semaphore to make sure that a
 925	 * module insertion/removal doesn't change anything
 926	 * under us.
 927	 */
 928	mutex_lock(&port->mutex);
 929	retval = uart_set_info(tty, port, state, &new_serial);
 930	mutex_unlock(&port->mutex);
 
 931	return retval;
 932}
 933
 934/**
 935 *	uart_get_lsr_info	-	get line status register info
 936 *	@tty: tty associated with the UART
 937 *	@state: UART being queried
 938 *	@value: returned modem value
 939 *
 940 *	Note: uart_ioctl protects us against hangups.
 941 */
 942static int uart_get_lsr_info(struct tty_struct *tty,
 943			struct uart_state *state, unsigned int __user *value)
 944{
 945	struct uart_port *uport = state->uart_port;
 946	unsigned int result;
 947
 948	result = uport->ops->tx_empty(uport);
 949
 950	/*
 951	 * If we're about to load something into the transmit
 952	 * register, we'll pretend the transmitter isn't empty to
 953	 * avoid a race condition (depending on when the transmit
 954	 * interrupt happens).
 955	 */
 956	if (uport->x_char ||
 957	    ((uart_circ_chars_pending(&state->xmit) > 0) &&
 958	     !uart_tx_stopped(uport)))
 959		result &= ~TIOCSER_TEMT;
 960
 961	return put_user(result, value);
 962}
 963
 964static int uart_tiocmget(struct tty_struct *tty)
 965{
 966	struct uart_state *state = tty->driver_data;
 967	struct tty_port *port = &state->port;
 968	struct uart_port *uport = state->uart_port;
 969	int result = -EIO;
 970
 971	mutex_lock(&port->mutex);
 972	if (!(tty->flags & (1 << TTY_IO_ERROR))) {
 
 
 
 
 973		result = uport->mctrl;
 974		spin_lock_irq(&uport->lock);
 975		result |= uport->ops->get_mctrl(uport);
 976		spin_unlock_irq(&uport->lock);
 977	}
 
 978	mutex_unlock(&port->mutex);
 979
 980	return result;
 981}
 982
 983static int
 984uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
 985{
 986	struct uart_state *state = tty->driver_data;
 987	struct uart_port *uport = state->uart_port;
 988	struct tty_port *port = &state->port;
 
 989	int ret = -EIO;
 990
 991	mutex_lock(&port->mutex);
 992	if (!(tty->flags & (1 << TTY_IO_ERROR))) {
 
 
 
 
 993		uart_update_mctrl(uport, set, clear);
 994		ret = 0;
 995	}
 
 996	mutex_unlock(&port->mutex);
 997	return ret;
 998}
 999
1000static int uart_break_ctl(struct tty_struct *tty, int break_state)
1001{
1002	struct uart_state *state = tty->driver_data;
1003	struct tty_port *port = &state->port;
1004	struct uart_port *uport = state->uart_port;
 
1005
1006	mutex_lock(&port->mutex);
 
 
 
1007
1008	if (uport->type != PORT_UNKNOWN)
1009		uport->ops->break_ctl(uport, break_state);
1010
 
1011	mutex_unlock(&port->mutex);
1012	return 0;
1013}
1014
1015static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1016{
1017	struct uart_port *uport = state->uart_port;
1018	struct tty_port *port = &state->port;
 
1019	int flags, ret;
1020
1021	if (!capable(CAP_SYS_ADMIN))
1022		return -EPERM;
1023
1024	/*
1025	 * Take the per-port semaphore.  This prevents count from
1026	 * changing, and hence any extra opens of the port while
1027	 * we're auto-configuring.
1028	 */
1029	if (mutex_lock_interruptible(&port->mutex))
1030		return -ERESTARTSYS;
1031
 
 
 
 
 
 
1032	ret = -EBUSY;
1033	if (tty_port_users(port) == 1) {
1034		uart_shutdown(tty, state);
1035
1036		/*
1037		 * If we already have a port type configured,
1038		 * we must release its resources.
1039		 */
1040		if (uport->type != PORT_UNKNOWN)
1041			uport->ops->release_port(uport);
1042
1043		flags = UART_CONFIG_TYPE;
1044		if (uport->flags & UPF_AUTO_IRQ)
1045			flags |= UART_CONFIG_IRQ;
1046
1047		/*
1048		 * This will claim the ports resources if
1049		 * a port is found.
1050		 */
1051		uport->ops->config_port(uport, flags);
1052
1053		ret = uart_startup(tty, state, 1);
 
 
 
 
1054	}
 
1055	mutex_unlock(&port->mutex);
1056	return ret;
1057}
1058
1059static void uart_enable_ms(struct uart_port *uport)
1060{
1061	/*
1062	 * Force modem status interrupts on
1063	 */
1064	if (uport->ops->enable_ms)
1065		uport->ops->enable_ms(uport);
1066}
1067
1068/*
1069 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1070 * - mask passed in arg for lines of interest
1071 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1072 * Caller should use TIOCGICOUNT to see which one it was
1073 *
1074 * FIXME: This wants extracting into a common all driver implementation
1075 * of TIOCMWAIT using tty_port.
1076 */
1077static int
1078uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1079{
1080	struct uart_port *uport = state->uart_port;
1081	struct tty_port *port = &state->port;
1082	DECLARE_WAITQUEUE(wait, current);
1083	struct uart_icount cprev, cnow;
1084	int ret;
1085
1086	/*
1087	 * note the counters on entry
1088	 */
 
 
 
1089	spin_lock_irq(&uport->lock);
1090	memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1091	uart_enable_ms(uport);
1092	spin_unlock_irq(&uport->lock);
1093
1094	add_wait_queue(&port->delta_msr_wait, &wait);
1095	for (;;) {
1096		spin_lock_irq(&uport->lock);
1097		memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1098		spin_unlock_irq(&uport->lock);
1099
1100		set_current_state(TASK_INTERRUPTIBLE);
1101
1102		if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1103		    ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1104		    ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
1105		    ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1106			ret = 0;
1107			break;
1108		}
1109
1110		schedule();
1111
1112		/* see if a signal did it */
1113		if (signal_pending(current)) {
1114			ret = -ERESTARTSYS;
1115			break;
1116		}
1117
1118		cprev = cnow;
1119	}
1120	__set_current_state(TASK_RUNNING);
1121	remove_wait_queue(&port->delta_msr_wait, &wait);
 
1122
1123	return ret;
1124}
1125
1126/*
1127 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1128 * Return: write counters to the user passed counter struct
1129 * NB: both 1->0 and 0->1 transitions are counted except for
1130 *     RI where only 0->1 is counted.
1131 */
1132static int uart_get_icount(struct tty_struct *tty,
1133			  struct serial_icounter_struct *icount)
1134{
1135	struct uart_state *state = tty->driver_data;
1136	struct uart_icount cnow;
1137	struct uart_port *uport = state->uart_port;
1138
 
 
 
1139	spin_lock_irq(&uport->lock);
1140	memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1141	spin_unlock_irq(&uport->lock);
 
1142
1143	icount->cts         = cnow.cts;
1144	icount->dsr         = cnow.dsr;
1145	icount->rng         = cnow.rng;
1146	icount->dcd         = cnow.dcd;
1147	icount->rx          = cnow.rx;
1148	icount->tx          = cnow.tx;
1149	icount->frame       = cnow.frame;
1150	icount->overrun     = cnow.overrun;
1151	icount->parity      = cnow.parity;
1152	icount->brk         = cnow.brk;
1153	icount->buf_overrun = cnow.buf_overrun;
1154
1155	return 0;
1156}
1157
1158static int uart_get_rs485_config(struct uart_port *port,
1159			 struct serial_rs485 __user *rs485)
1160{
1161	unsigned long flags;
1162	struct serial_rs485 aux;
1163
1164	spin_lock_irqsave(&port->lock, flags);
1165	aux = port->rs485;
1166	spin_unlock_irqrestore(&port->lock, flags);
1167
1168	if (copy_to_user(rs485, &aux, sizeof(aux)))
1169		return -EFAULT;
1170
1171	return 0;
1172}
1173
1174static int uart_set_rs485_config(struct uart_port *port,
1175			 struct serial_rs485 __user *rs485_user)
1176{
1177	struct serial_rs485 rs485;
1178	int ret;
1179	unsigned long flags;
1180
1181	if (!port->rs485_config)
1182		return -ENOIOCTLCMD;
1183
1184	if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
1185		return -EFAULT;
1186
1187	spin_lock_irqsave(&port->lock, flags);
1188	ret = port->rs485_config(port, &rs485);
1189	spin_unlock_irqrestore(&port->lock, flags);
1190	if (ret)
1191		return ret;
1192
1193	if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
1194		return -EFAULT;
1195
1196	return 0;
1197}
1198
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1199/*
1200 * Called via sys_ioctl.  We can use spin_lock_irq() here.
1201 */
1202static int
1203uart_ioctl(struct tty_struct *tty, unsigned int cmd,
1204	   unsigned long arg)
1205{
1206	struct uart_state *state = tty->driver_data;
1207	struct tty_port *port = &state->port;
 
1208	void __user *uarg = (void __user *)arg;
1209	int ret = -ENOIOCTLCMD;
1210
1211
1212	/*
1213	 * These ioctls don't rely on the hardware to be present.
1214	 */
1215	switch (cmd) {
1216	case TIOCGSERIAL:
1217		ret = uart_get_info_user(port, uarg);
1218		break;
1219
1220	case TIOCSSERIAL:
1221		down_write(&tty->termios_rwsem);
1222		ret = uart_set_info_user(tty, state, uarg);
1223		up_write(&tty->termios_rwsem);
1224		break;
1225
1226	case TIOCSERCONFIG:
1227		down_write(&tty->termios_rwsem);
1228		ret = uart_do_autoconfig(tty, state);
1229		up_write(&tty->termios_rwsem);
1230		break;
1231
1232	case TIOCSERGWILD: /* obsolete */
1233	case TIOCSERSWILD: /* obsolete */
1234		ret = 0;
1235		break;
1236	}
1237
1238	if (ret != -ENOIOCTLCMD)
1239		goto out;
1240
1241	if (tty->flags & (1 << TTY_IO_ERROR)) {
1242		ret = -EIO;
1243		goto out;
1244	}
1245
1246	/*
1247	 * The following should only be used when hardware is present.
1248	 */
1249	switch (cmd) {
1250	case TIOCMIWAIT:
1251		ret = uart_wait_modem_status(state, arg);
1252		break;
1253	}
1254
1255	if (ret != -ENOIOCTLCMD)
1256		goto out;
1257
1258	mutex_lock(&port->mutex);
 
1259
1260	if (tty->flags & (1 << TTY_IO_ERROR)) {
1261		ret = -EIO;
1262		goto out_up;
1263	}
1264
1265	/*
1266	 * All these rely on hardware being present and need to be
1267	 * protected against the tty being hung up.
1268	 */
1269
1270	switch (cmd) {
1271	case TIOCSERGETLSR: /* Get line status register */
1272		ret = uart_get_lsr_info(tty, state, uarg);
1273		break;
1274
1275	case TIOCGRS485:
1276		ret = uart_get_rs485_config(state->uart_port, uarg);
1277		break;
1278
1279	case TIOCSRS485:
1280		ret = uart_set_rs485_config(state->uart_port, uarg);
 
 
 
 
 
 
 
 
1281		break;
1282	default: {
1283		struct uart_port *uport = state->uart_port;
1284		if (uport->ops->ioctl)
1285			ret = uport->ops->ioctl(uport, cmd, arg);
1286		break;
1287	}
1288	}
1289out_up:
1290	mutex_unlock(&port->mutex);
1291out:
1292	return ret;
1293}
1294
1295static void uart_set_ldisc(struct tty_struct *tty)
1296{
1297	struct uart_state *state = tty->driver_data;
1298	struct uart_port *uport = state->uart_port;
1299
1300	if (uport->ops->set_ldisc) {
1301		mutex_lock(&state->port.mutex);
 
1302		uport->ops->set_ldisc(uport, &tty->termios);
1303		mutex_unlock(&state->port.mutex);
1304	}
1305}
1306
1307static void uart_set_termios(struct tty_struct *tty,
1308						struct ktermios *old_termios)
1309{
1310	struct uart_state *state = tty->driver_data;
1311	struct uart_port *uport = state->uart_port;
1312	unsigned int cflag = tty->termios.c_cflag;
1313	unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1314	bool sw_changed = false;
1315
 
 
 
 
 
1316	/*
1317	 * Drivers doing software flow control also need to know
1318	 * about changes to these input settings.
1319	 */
1320	if (uport->flags & UPF_SOFT_FLOW) {
1321		iflag_mask |= IXANY|IXON|IXOFF;
1322		sw_changed =
1323		   tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1324		   tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1325	}
1326
1327	/*
1328	 * These are the bits that are used to setup various
1329	 * flags in the low level driver. We can ignore the Bfoo
1330	 * bits in c_cflag; c_[io]speed will always be set
1331	 * appropriately by set_termios() in tty_ioctl.c
1332	 */
1333	if ((cflag ^ old_termios->c_cflag) == 0 &&
1334	    tty->termios.c_ospeed == old_termios->c_ospeed &&
1335	    tty->termios.c_ispeed == old_termios->c_ispeed &&
1336	    ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1337	    !sw_changed) {
1338		return;
1339	}
1340
1341	mutex_lock(&state->port.mutex);
1342	uart_change_speed(tty, state, old_termios);
1343	mutex_unlock(&state->port.mutex);
1344	/* reload cflag from termios; port driver may have overriden flags */
1345	cflag = tty->termios.c_cflag;
1346
1347	/* Handle transition to B0 status */
1348	if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1349		uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1350	/* Handle transition away from B0 status */
1351	else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1352		unsigned int mask = TIOCM_DTR;
1353		if (!(cflag & CRTSCTS) || !test_bit(TTY_THROTTLED, &tty->flags))
 
1354			mask |= TIOCM_RTS;
1355		uart_set_mctrl(uport, mask);
1356	}
 
 
1357}
1358
1359/*
1360 * Calls to uart_close() are serialised via the tty_lock in
1361 *   drivers/tty/tty_io.c:tty_release()
1362 *   drivers/tty/tty_io.c:do_tty_hangup()
1363 * This runs from a workqueue and can sleep for a _short_ time only.
1364 */
1365static void uart_close(struct tty_struct *tty, struct file *filp)
1366{
1367	struct uart_state *state = tty->driver_data;
1368	struct tty_port *port;
1369	struct uart_port *uport;
1370
1371	if (!state) {
1372		struct uart_driver *drv = tty->driver->driver_state;
 
1373
1374		state = drv->state + tty->index;
1375		port = &state->port;
1376		spin_lock_irq(&port->lock);
1377		--port->count;
1378		spin_unlock_irq(&port->lock);
1379		return;
1380	}
1381
1382	uport = state->uart_port;
1383	port = &state->port;
1384	pr_debug("uart_close(%d) called\n", tty->index);
1385
1386	if (!port->count || tty_port_close_start(port, tty, filp) == 0)
1387		return;
 
 
 
 
 
1388
1389	/*
1390	 * At this point, we stop accepting input.  To do this, we
1391	 * disable the receive line status interrupts.
1392	 */
1393	if (port->flags & ASYNC_INITIALIZED) {
1394		spin_lock_irq(&uport->lock);
1395		uport->ops->stop_rx(uport);
1396		spin_unlock_irq(&uport->lock);
1397		/*
1398		 * Before we drop DTR, make sure the UART transmitter
1399		 * has completely drained; this is especially
1400		 * important if there is a transmit FIFO!
1401		 */
1402		uart_wait_until_sent(tty, uport->timeout);
1403	}
1404
1405	mutex_lock(&port->mutex);
1406	uart_shutdown(tty, state);
1407	tty_port_tty_set(port, NULL);
1408
1409	spin_lock_irq(&port->lock);
1410
1411	if (port->blocked_open) {
1412		spin_unlock_irq(&port->lock);
1413		if (port->close_delay)
1414			msleep_interruptible(jiffies_to_msecs(port->close_delay));
1415		spin_lock_irq(&port->lock);
1416	} else if (!uart_console(uport)) {
1417		spin_unlock_irq(&port->lock);
1418		uart_change_pm(state, UART_PM_STATE_OFF);
1419		spin_lock_irq(&port->lock);
1420	}
1421
1422	/*
1423	 * Wake up anyone trying to open this port.
 
 
1424	 */
1425	clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1426	spin_unlock_irq(&port->lock);
1427	wake_up_interruptible(&port->open_wait);
1428
1429	mutex_unlock(&port->mutex);
1430
1431	tty_ldisc_flush(tty);
1432	tty->closing = 0;
1433}
1434
1435static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1436{
1437	struct uart_state *state = tty->driver_data;
1438	struct uart_port *port = state->uart_port;
1439	unsigned long char_time, expire;
1440
1441	if (port->type == PORT_UNKNOWN || port->fifosize == 0)
 
 
 
 
 
1442		return;
 
1443
1444	/*
1445	 * Set the check interval to be 1/5 of the estimated time to
1446	 * send a single character, and make it at least 1.  The check
1447	 * interval should also be less than the timeout.
1448	 *
1449	 * Note: we have to use pretty tight timings here to satisfy
1450	 * the NIST-PCTS.
1451	 */
1452	char_time = (port->timeout - HZ/50) / port->fifosize;
1453	char_time = char_time / 5;
1454	if (char_time == 0)
1455		char_time = 1;
1456	if (timeout && timeout < char_time)
1457		char_time = timeout;
1458
1459	/*
1460	 * If the transmitter hasn't cleared in twice the approximate
1461	 * amount of time to send the entire FIFO, it probably won't
1462	 * ever clear.  This assumes the UART isn't doing flow
1463	 * control, which is currently the case.  Hence, if it ever
1464	 * takes longer than port->timeout, this is probably due to a
1465	 * UART bug of some kind.  So, we clamp the timeout parameter at
1466	 * 2*port->timeout.
1467	 */
1468	if (timeout == 0 || timeout > 2 * port->timeout)
1469		timeout = 2 * port->timeout;
1470
1471	expire = jiffies + timeout;
1472
1473	pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1474		port->line, jiffies, expire);
1475
1476	/*
1477	 * Check whether the transmitter is empty every 'char_time'.
1478	 * 'timeout' / 'expire' give us the maximum amount of time
1479	 * we wait.
1480	 */
1481	while (!port->ops->tx_empty(port)) {
1482		msleep_interruptible(jiffies_to_msecs(char_time));
1483		if (signal_pending(current))
1484			break;
1485		if (time_after(jiffies, expire))
1486			break;
1487	}
 
1488}
1489
1490/*
1491 * Calls to uart_hangup() are serialised by the tty_lock in
1492 *   drivers/tty/tty_io.c:do_tty_hangup()
1493 * This runs from a workqueue and can sleep for a _short_ time only.
1494 */
1495static void uart_hangup(struct tty_struct *tty)
1496{
1497	struct uart_state *state = tty->driver_data;
1498	struct tty_port *port = &state->port;
 
1499	unsigned long flags;
1500
1501	pr_debug("uart_hangup(%d)\n", tty->index);
1502
1503	mutex_lock(&port->mutex);
1504	if (port->flags & ASYNC_NORMAL_ACTIVE) {
 
 
 
1505		uart_flush_buffer(tty);
1506		uart_shutdown(tty, state);
1507		spin_lock_irqsave(&port->lock, flags);
1508		port->count = 0;
1509		clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
1510		spin_unlock_irqrestore(&port->lock, flags);
 
1511		tty_port_tty_set(port, NULL);
1512		if (!uart_console(state->uart_port))
1513			uart_change_pm(state, UART_PM_STATE_OFF);
1514		wake_up_interruptible(&port->open_wait);
1515		wake_up_interruptible(&port->delta_msr_wait);
1516	}
1517	mutex_unlock(&port->mutex);
1518}
1519
 
1520static void uart_port_shutdown(struct tty_port *port)
1521{
1522	struct uart_state *state = container_of(port, struct uart_state, port);
1523	struct uart_port *uport = state->uart_port;
1524
1525	/*
1526	 * clear delta_msr_wait queue to avoid mem leaks: we may free
1527	 * the irq here so the queue might never be woken up.  Note
1528	 * that we won't end up waiting on delta_msr_wait again since
1529	 * any outstanding file descriptors should be pointing at
1530	 * hung_up_tty_fops now.
1531	 */
1532	wake_up_interruptible(&port->delta_msr_wait);
1533
1534	/*
1535	 * Free the IRQ and disable the port.
1536	 */
1537	uport->ops->shutdown(uport);
 
1538
1539	/*
1540	 * Ensure that the IRQ handler isn't running on another CPU.
1541	 */
1542	synchronize_irq(uport->irq);
 
1543}
1544
1545static int uart_carrier_raised(struct tty_port *port)
1546{
1547	struct uart_state *state = container_of(port, struct uart_state, port);
1548	struct uart_port *uport = state->uart_port;
1549	int mctrl;
 
 
 
 
 
 
 
 
 
 
1550	spin_lock_irq(&uport->lock);
1551	uart_enable_ms(uport);
1552	mctrl = uport->ops->get_mctrl(uport);
1553	spin_unlock_irq(&uport->lock);
 
1554	if (mctrl & TIOCM_CAR)
1555		return 1;
1556	return 0;
1557}
1558
1559static void uart_dtr_rts(struct tty_port *port, int onoff)
1560{
1561	struct uart_state *state = container_of(port, struct uart_state, port);
1562	struct uart_port *uport = state->uart_port;
1563
1564	if (onoff)
1565		uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
1566	else
1567		uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
 
 
 
 
 
 
 
 
 
 
 
1568}
1569
1570/*
1571 * Calls to uart_open are serialised by the tty_lock in
1572 *   drivers/tty/tty_io.c:tty_open()
1573 * Note that if this fails, then uart_close() _will_ be called.
1574 *
1575 * In time, we want to scrap the "opening nonpresent ports"
1576 * behaviour and implement an alternative way for setserial
1577 * to set base addresses/ports/types.  This will allow us to
1578 * get rid of a certain amount of extra tests.
1579 */
1580static int uart_open(struct tty_struct *tty, struct file *filp)
1581{
1582	struct uart_driver *drv = tty->driver->driver_state;
1583	int retval, line = tty->index;
1584	struct uart_state *state = drv->state + line;
1585	struct tty_port *port = &state->port;
1586
1587	pr_debug("uart_open(%d) called\n", line);
 
 
1588
1589	spin_lock_irq(&port->lock);
1590	++port->count;
1591	spin_unlock_irq(&port->lock);
1592
1593	/*
1594	 * We take the semaphore here to guarantee that we won't be re-entered
1595	 * while allocating the state structure, or while we request any IRQs
1596	 * that the driver may need.  This also has the nice side-effect that
1597	 * it delays the action of uart_hangup, so we can guarantee that
1598	 * state->port.tty will always contain something reasonable.
1599	 */
1600	if (mutex_lock_interruptible(&port->mutex)) {
1601		retval = -ERESTARTSYS;
1602		goto end;
1603	}
1604
1605	if (!state->uart_port || state->uart_port->flags & UPF_DEAD) {
1606		retval = -ENXIO;
1607		goto err_unlock;
1608	}
1609
1610	tty->driver_data = state;
1611	state->uart_port->state = state;
1612	state->port.low_latency =
1613		(state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
1614	tty_port_tty_set(port, tty);
1615
1616	/*
1617	 * Start up the serial port.
1618	 */
1619	retval = uart_startup(tty, state, 0);
 
 
1620
1621	/*
1622	 * If we succeeded, wait until the port is ready.
1623	 */
1624err_unlock:
1625	mutex_unlock(&port->mutex);
1626	if (retval == 0)
1627		retval = tty_port_block_til_ready(port, tty, filp);
1628end:
1629	return retval;
1630}
1631
1632static const char *uart_type(struct uart_port *port)
1633{
1634	const char *str = NULL;
1635
1636	if (port->ops->type)
1637		str = port->ops->type(port);
1638
1639	if (!str)
1640		str = "unknown";
1641
1642	return str;
1643}
1644
1645#ifdef CONFIG_PROC_FS
1646
1647static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1648{
1649	struct uart_state *state = drv->state + i;
1650	struct tty_port *port = &state->port;
1651	enum uart_pm_state pm_state;
1652	struct uart_port *uport = state->uart_port;
1653	char stat_buf[32];
1654	unsigned int status;
1655	int mmio;
1656
 
 
1657	if (!uport)
1658		return;
1659
1660	mmio = uport->iotype >= UPIO_MEM;
1661	seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1662			uport->line, uart_type(uport),
1663			mmio ? "mmio:0x" : "port:",
1664			mmio ? (unsigned long long)uport->mapbase
1665			     : (unsigned long long)uport->iobase,
1666			uport->irq);
1667
1668	if (uport->type == PORT_UNKNOWN) {
1669		seq_putc(m, '\n');
1670		return;
1671	}
1672
1673	if (capable(CAP_SYS_ADMIN)) {
1674		mutex_lock(&port->mutex);
1675		pm_state = state->pm_state;
1676		if (pm_state != UART_PM_STATE_ON)
1677			uart_change_pm(state, UART_PM_STATE_ON);
1678		spin_lock_irq(&uport->lock);
1679		status = uport->ops->get_mctrl(uport);
1680		spin_unlock_irq(&uport->lock);
1681		if (pm_state != UART_PM_STATE_ON)
1682			uart_change_pm(state, pm_state);
1683		mutex_unlock(&port->mutex);
1684
1685		seq_printf(m, " tx:%d rx:%d",
1686				uport->icount.tx, uport->icount.rx);
1687		if (uport->icount.frame)
1688			seq_printf(m, " fe:%d",	uport->icount.frame);
1689		if (uport->icount.parity)
1690			seq_printf(m, " pe:%d",	uport->icount.parity);
1691		if (uport->icount.brk)
1692			seq_printf(m, " brk:%d", uport->icount.brk);
1693		if (uport->icount.overrun)
1694			seq_printf(m, " oe:%d", uport->icount.overrun);
 
 
1695
1696#define INFOBIT(bit, str) \
1697	if (uport->mctrl & (bit)) \
1698		strncat(stat_buf, (str), sizeof(stat_buf) - \
1699			strlen(stat_buf) - 2)
1700#define STATBIT(bit, str) \
1701	if (status & (bit)) \
1702		strncat(stat_buf, (str), sizeof(stat_buf) - \
1703		       strlen(stat_buf) - 2)
1704
1705		stat_buf[0] = '\0';
1706		stat_buf[1] = '\0';
1707		INFOBIT(TIOCM_RTS, "|RTS");
1708		STATBIT(TIOCM_CTS, "|CTS");
1709		INFOBIT(TIOCM_DTR, "|DTR");
1710		STATBIT(TIOCM_DSR, "|DSR");
1711		STATBIT(TIOCM_CAR, "|CD");
1712		STATBIT(TIOCM_RNG, "|RI");
1713		if (stat_buf[0])
1714			stat_buf[0] = ' ';
1715
1716		seq_puts(m, stat_buf);
1717	}
1718	seq_putc(m, '\n');
1719#undef STATBIT
1720#undef INFOBIT
 
 
1721}
1722
1723static int uart_proc_show(struct seq_file *m, void *v)
1724{
1725	struct tty_driver *ttydrv = m->private;
1726	struct uart_driver *drv = ttydrv->driver_state;
1727	int i;
1728
1729	seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", "");
1730	for (i = 0; i < drv->nr; i++)
1731		uart_line_info(m, drv, i);
1732	return 0;
1733}
 
1734
1735static int uart_proc_open(struct inode *inode, struct file *file)
1736{
1737	return single_open(file, uart_proc_show, PDE_DATA(inode));
1738}
1739
1740static const struct file_operations uart_proc_fops = {
1741	.owner		= THIS_MODULE,
1742	.open		= uart_proc_open,
1743	.read		= seq_read,
1744	.llseek		= seq_lseek,
1745	.release	= single_release,
1746};
1747#endif
1748
1749#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1750/**
1751 *	uart_console_write - write a console message to a serial port
1752 *	@port: the port to write the message
1753 *	@s: array of characters
1754 *	@count: number of characters in string to write
1755 *	@putchar: function to write character to port
1756 */
1757void uart_console_write(struct uart_port *port, const char *s,
1758			unsigned int count,
1759			void (*putchar)(struct uart_port *, int))
1760{
1761	unsigned int i;
1762
1763	for (i = 0; i < count; i++, s++) {
1764		if (*s == '\n')
1765			putchar(port, '\r');
1766		putchar(port, *s);
1767	}
1768}
1769EXPORT_SYMBOL_GPL(uart_console_write);
1770
1771/*
1772 *	Check whether an invalid uart number has been specified, and
1773 *	if so, search for the first available port that does have
1774 *	console support.
1775 */
1776struct uart_port * __init
1777uart_get_console(struct uart_port *ports, int nr, struct console *co)
1778{
1779	int idx = co->index;
1780
1781	if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1782				     ports[idx].membase == NULL))
1783		for (idx = 0; idx < nr; idx++)
1784			if (ports[idx].iobase != 0 ||
1785			    ports[idx].membase != NULL)
1786				break;
1787
1788	co->index = idx;
1789
1790	return ports + idx;
1791}
1792
1793/**
1794 *	uart_parse_earlycon - Parse earlycon options
1795 *	@p:	  ptr to 2nd field (ie., just beyond '<name>,')
1796 *	@iotype:  ptr for decoded iotype (out)
1797 *	@addr:    ptr for decoded mapbase/iobase (out)
1798 *	@options: ptr for <options> field; NULL if not present (out)
1799 *
1800 *	Decodes earlycon kernel command line parameters of the form
1801 *	   earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1802 *	   console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1803 *
1804 *	The optional form
 
1805 *	   earlycon=<name>,0x<addr>,<options>
1806 *	   console=<name>,0x<addr>,<options>
 
1807 *	is also accepted; the returned @iotype will be UPIO_MEM.
1808 *
1809 *	Returns 0 on success or -EINVAL on failure
1810 */
1811int uart_parse_earlycon(char *p, unsigned char *iotype, unsigned long *addr,
1812			char **options)
1813{
1814	if (strncmp(p, "mmio,", 5) == 0) {
1815		*iotype = UPIO_MEM;
1816		p += 5;
1817	} else if (strncmp(p, "mmio16,", 7) == 0) {
1818		*iotype = UPIO_MEM16;
1819		p += 7;
1820	} else if (strncmp(p, "mmio32,", 7) == 0) {
1821		*iotype = UPIO_MEM32;
1822		p += 7;
1823	} else if (strncmp(p, "mmio32be,", 9) == 0) {
1824		*iotype = UPIO_MEM32BE;
1825		p += 9;
1826	} else if (strncmp(p, "mmio32native,", 13) == 0) {
1827		*iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ?
1828			UPIO_MEM32BE : UPIO_MEM32;
1829		p += 13;
1830	} else if (strncmp(p, "io,", 3) == 0) {
1831		*iotype = UPIO_PORT;
1832		p += 3;
1833	} else if (strncmp(p, "0x", 2) == 0) {
1834		*iotype = UPIO_MEM;
1835	} else {
1836		return -EINVAL;
1837	}
1838
1839	*addr = simple_strtoul(p, NULL, 0);
 
 
 
 
1840	p = strchr(p, ',');
1841	if (p)
1842		p++;
1843
1844	*options = p;
1845	return 0;
1846}
1847EXPORT_SYMBOL_GPL(uart_parse_earlycon);
1848
1849/**
1850 *	uart_parse_options - Parse serial port baud/parity/bits/flow control.
1851 *	@options: pointer to option string
1852 *	@baud: pointer to an 'int' variable for the baud rate.
1853 *	@parity: pointer to an 'int' variable for the parity.
1854 *	@bits: pointer to an 'int' variable for the number of data bits.
1855 *	@flow: pointer to an 'int' variable for the flow control character.
1856 *
1857 *	uart_parse_options decodes a string containing the serial console
1858 *	options.  The format of the string is <baud><parity><bits><flow>,
1859 *	eg: 115200n8r
1860 */
1861void
1862uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow)
 
1863{
1864	char *s = options;
1865
1866	*baud = simple_strtoul(s, NULL, 10);
1867	while (*s >= '0' && *s <= '9')
1868		s++;
1869	if (*s)
1870		*parity = *s++;
1871	if (*s)
1872		*bits = *s++ - '0';
1873	if (*s)
1874		*flow = *s;
1875}
1876EXPORT_SYMBOL_GPL(uart_parse_options);
1877
1878/**
1879 *	uart_set_options - setup the serial console parameters
1880 *	@port: pointer to the serial ports uart_port structure
1881 *	@co: console pointer
1882 *	@baud: baud rate
1883 *	@parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
1884 *	@bits: number of data bits
1885 *	@flow: flow control character - 'r' (rts)
1886 */
1887int
1888uart_set_options(struct uart_port *port, struct console *co,
1889		 int baud, int parity, int bits, int flow)
1890{
1891	struct ktermios termios;
1892	static struct ktermios dummy;
1893
1894	/*
1895	 * Ensure that the serial console lock is initialised
1896	 * early.
1897	 * If this port is a console, then the spinlock is already
1898	 * initialised.
 
1899	 */
1900	if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
1901		spin_lock_init(&port->lock);
1902		lockdep_set_class(&port->lock, &port_lock_key);
1903	}
1904
1905	memset(&termios, 0, sizeof(struct ktermios));
1906
1907	termios.c_cflag |= CREAD | HUPCL | CLOCAL;
1908	tty_termios_encode_baud_rate(&termios, baud, baud);
1909
1910	if (bits == 7)
1911		termios.c_cflag |= CS7;
1912	else
1913		termios.c_cflag |= CS8;
1914
1915	switch (parity) {
1916	case 'o': case 'O':
1917		termios.c_cflag |= PARODD;
1918		/*fall through*/
1919	case 'e': case 'E':
1920		termios.c_cflag |= PARENB;
1921		break;
1922	}
1923
1924	if (flow == 'r')
1925		termios.c_cflag |= CRTSCTS;
1926
1927	/*
1928	 * some uarts on other side don't support no flow control.
1929	 * So we set * DTR in host uart to make them happy
1930	 */
1931	port->mctrl |= TIOCM_DTR;
1932
1933	port->ops->set_termios(port, &termios, &dummy);
1934	/*
1935	 * Allow the setting of the UART parameters with a NULL console
1936	 * too:
1937	 */
1938	if (co)
1939		co->cflag = termios.c_cflag;
1940
1941	return 0;
1942}
1943EXPORT_SYMBOL_GPL(uart_set_options);
1944#endif /* CONFIG_SERIAL_CORE_CONSOLE */
1945
1946/**
1947 * uart_change_pm - set power state of the port
1948 *
1949 * @state: port descriptor
1950 * @pm_state: new state
1951 *
1952 * Locking: port->mutex has to be held
1953 */
1954static void uart_change_pm(struct uart_state *state,
1955			   enum uart_pm_state pm_state)
1956{
1957	struct uart_port *port = state->uart_port;
1958
1959	if (state->pm_state != pm_state) {
1960		if (port->ops->pm)
1961			port->ops->pm(port, pm_state, state->pm_state);
1962		state->pm_state = pm_state;
1963	}
1964}
1965
1966struct uart_match {
1967	struct uart_port *port;
1968	struct uart_driver *driver;
1969};
1970
1971static int serial_match_port(struct device *dev, void *data)
1972{
1973	struct uart_match *match = data;
1974	struct tty_driver *tty_drv = match->driver->tty_driver;
1975	dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
1976		match->port->line;
1977
1978	return dev->devt == devt; /* Actually, only one tty per port */
1979}
1980
1981int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
1982{
1983	struct uart_state *state = drv->state + uport->line;
1984	struct tty_port *port = &state->port;
1985	struct device *tty_dev;
1986	struct uart_match match = {uport, drv};
1987
1988	mutex_lock(&port->mutex);
1989
1990	tty_dev = device_find_child(uport->dev, &match, serial_match_port);
1991	if (device_may_wakeup(tty_dev)) {
1992		if (!enable_irq_wake(uport->irq))
1993			uport->irq_wake = 1;
1994		put_device(tty_dev);
1995		mutex_unlock(&port->mutex);
1996		return 0;
1997	}
1998	put_device(tty_dev);
1999
2000	/* Nothing to do if the console is not suspending */
2001	if (!console_suspend_enabled && uart_console(uport))
2002		goto unlock;
2003
2004	uport->suspended = 1;
2005
2006	if (port->flags & ASYNC_INITIALIZED) {
2007		const struct uart_ops *ops = uport->ops;
2008		int tries;
2009
2010		set_bit(ASYNCB_SUSPENDED, &port->flags);
2011		clear_bit(ASYNCB_INITIALIZED, &port->flags);
2012
2013		spin_lock_irq(&uport->lock);
2014		ops->stop_tx(uport);
2015		ops->set_mctrl(uport, 0);
2016		ops->stop_rx(uport);
2017		spin_unlock_irq(&uport->lock);
2018
2019		/*
2020		 * Wait for the transmitter to empty.
2021		 */
2022		for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2023			msleep(10);
2024		if (!tries)
2025			dev_err(uport->dev, "%s%d: Unable to drain transmitter\n",
2026				drv->dev_name,
2027				drv->tty_driver->name_base + uport->line);
2028
2029		ops->shutdown(uport);
2030	}
2031
2032	/*
2033	 * Disable the console device before suspending.
2034	 */
2035	if (uart_console(uport))
2036		console_stop(uport->cons);
2037
2038	uart_change_pm(state, UART_PM_STATE_OFF);
2039unlock:
2040	mutex_unlock(&port->mutex);
2041
2042	return 0;
2043}
2044
2045int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2046{
2047	struct uart_state *state = drv->state + uport->line;
2048	struct tty_port *port = &state->port;
2049	struct device *tty_dev;
2050	struct uart_match match = {uport, drv};
2051	struct ktermios termios;
2052
2053	mutex_lock(&port->mutex);
2054
2055	tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2056	if (!uport->suspended && device_may_wakeup(tty_dev)) {
2057		if (uport->irq_wake) {
2058			disable_irq_wake(uport->irq);
2059			uport->irq_wake = 0;
2060		}
2061		put_device(tty_dev);
2062		mutex_unlock(&port->mutex);
2063		return 0;
2064	}
2065	put_device(tty_dev);
2066	uport->suspended = 0;
2067
2068	/*
2069	 * Re-enable the console device after suspending.
2070	 */
2071	if (uart_console(uport)) {
2072		/*
2073		 * First try to use the console cflag setting.
2074		 */
2075		memset(&termios, 0, sizeof(struct ktermios));
2076		termios.c_cflag = uport->cons->cflag;
2077
2078		/*
2079		 * If that's unset, use the tty termios setting.
2080		 */
2081		if (port->tty && termios.c_cflag == 0)
2082			termios = port->tty->termios;
2083
2084		if (console_suspend_enabled)
2085			uart_change_pm(state, UART_PM_STATE_ON);
2086		uport->ops->set_termios(uport, &termios, NULL);
2087		if (console_suspend_enabled)
2088			console_start(uport->cons);
2089	}
2090
2091	if (port->flags & ASYNC_SUSPENDED) {
2092		const struct uart_ops *ops = uport->ops;
2093		int ret;
2094
2095		uart_change_pm(state, UART_PM_STATE_ON);
2096		spin_lock_irq(&uport->lock);
2097		ops->set_mctrl(uport, 0);
2098		spin_unlock_irq(&uport->lock);
2099		if (console_suspend_enabled || !uart_console(uport)) {
2100			/* Protected by port mutex for now */
2101			struct tty_struct *tty = port->tty;
 
2102			ret = ops->startup(uport);
2103			if (ret == 0) {
2104				if (tty)
2105					uart_change_speed(tty, state, NULL);
2106				spin_lock_irq(&uport->lock);
2107				ops->set_mctrl(uport, uport->mctrl);
2108				ops->start_tx(uport);
2109				spin_unlock_irq(&uport->lock);
2110				set_bit(ASYNCB_INITIALIZED, &port->flags);
2111			} else {
2112				/*
2113				 * Failed to resume - maybe hardware went away?
2114				 * Clear the "initialized" flag so we won't try
2115				 * to call the low level drivers shutdown method.
2116				 */
2117				uart_shutdown(tty, state);
2118			}
2119		}
2120
2121		clear_bit(ASYNCB_SUSPENDED, &port->flags);
2122	}
2123
2124	mutex_unlock(&port->mutex);
2125
2126	return 0;
2127}
2128
2129static inline void
2130uart_report_port(struct uart_driver *drv, struct uart_port *port)
2131{
2132	char address[64];
2133
2134	switch (port->iotype) {
2135	case UPIO_PORT:
2136		snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2137		break;
2138	case UPIO_HUB6:
2139		snprintf(address, sizeof(address),
2140			 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2141		break;
2142	case UPIO_MEM:
2143	case UPIO_MEM16:
2144	case UPIO_MEM32:
2145	case UPIO_MEM32BE:
2146	case UPIO_AU:
2147	case UPIO_TSI:
2148		snprintf(address, sizeof(address),
2149			 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2150		break;
2151	default:
2152		strlcpy(address, "*unknown*", sizeof(address));
2153		break;
2154	}
2155
2156	printk(KERN_INFO "%s%s%s%d at %s (irq = %d, base_baud = %d) is a %s\n",
2157	       port->dev ? dev_name(port->dev) : "",
2158	       port->dev ? ": " : "",
2159	       drv->dev_name,
2160	       drv->tty_driver->name_base + port->line,
2161	       address, port->irq, port->uartclk / 16, uart_type(port));
2162}
2163
2164static void
2165uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2166		    struct uart_port *port)
2167{
2168	unsigned int flags;
2169
2170	/*
2171	 * If there isn't a port here, don't do anything further.
2172	 */
2173	if (!port->iobase && !port->mapbase && !port->membase)
2174		return;
2175
2176	/*
2177	 * Now do the auto configuration stuff.  Note that config_port
2178	 * is expected to claim the resources and map the port for us.
2179	 */
2180	flags = 0;
2181	if (port->flags & UPF_AUTO_IRQ)
2182		flags |= UART_CONFIG_IRQ;
2183	if (port->flags & UPF_BOOT_AUTOCONF) {
2184		if (!(port->flags & UPF_FIXED_TYPE)) {
2185			port->type = PORT_UNKNOWN;
2186			flags |= UART_CONFIG_TYPE;
2187		}
2188		port->ops->config_port(port, flags);
2189	}
2190
2191	if (port->type != PORT_UNKNOWN) {
2192		unsigned long flags;
2193
2194		uart_report_port(drv, port);
2195
2196		/* Power up port for set_mctrl() */
2197		uart_change_pm(state, UART_PM_STATE_ON);
2198
2199		/*
2200		 * Ensure that the modem control lines are de-activated.
2201		 * keep the DTR setting that is set in uart_set_options()
2202		 * We probably don't need a spinlock around this, but
2203		 */
2204		spin_lock_irqsave(&port->lock, flags);
2205		port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2206		spin_unlock_irqrestore(&port->lock, flags);
2207
2208		/*
2209		 * If this driver supports console, and it hasn't been
2210		 * successfully registered yet, try to re-register it.
2211		 * It may be that the port was not available.
2212		 */
2213		if (port->cons && !(port->cons->flags & CON_ENABLED))
2214			register_console(port->cons);
2215
2216		/*
2217		 * Power down all ports by default, except the
2218		 * console if we have one.
2219		 */
2220		if (!uart_console(port))
2221			uart_change_pm(state, UART_PM_STATE_OFF);
2222	}
2223}
2224
2225#ifdef CONFIG_CONSOLE_POLL
2226
2227static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2228{
2229	struct uart_driver *drv = driver->driver_state;
2230	struct uart_state *state = drv->state + line;
 
2231	struct uart_port *port;
2232	int baud = 9600;
2233	int bits = 8;
2234	int parity = 'n';
2235	int flow = 'n';
2236	int ret;
2237
2238	if (!state || !state->uart_port)
2239		return -1;
2240
2241	port = state->uart_port;
2242	if (!(port->ops->poll_get_char && port->ops->poll_put_char))
2243		return -1;
 
 
2244
2245	if (port->ops->poll_init) {
2246		struct tty_port *tport = &state->port;
2247
2248		ret = 0;
2249		mutex_lock(&tport->mutex);
2250		/*
2251		 * We don't set ASYNCB_INITIALIZED as we only initialized the
2252		 * hw, e.g. state->xmit is still uninitialized.
2253		 */
2254		if (!test_bit(ASYNCB_INITIALIZED, &tport->flags))
2255			ret = port->ops->poll_init(port);
2256		mutex_unlock(&tport->mutex);
2257		if (ret)
2258			return ret;
2259	}
2260
2261	if (options) {
2262		uart_parse_options(options, &baud, &parity, &bits, &flow);
2263		return uart_set_options(port, NULL, baud, parity, bits, flow);
2264	}
2265
2266	return 0;
 
2267}
2268
2269static int uart_poll_get_char(struct tty_driver *driver, int line)
2270{
2271	struct uart_driver *drv = driver->driver_state;
2272	struct uart_state *state = drv->state + line;
2273	struct uart_port *port;
 
2274
2275	if (!state || !state->uart_port)
2276		return -1;
 
 
 
2277
2278	port = state->uart_port;
2279	return port->ops->poll_get_char(port);
2280}
2281
2282static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2283{
2284	struct uart_driver *drv = driver->driver_state;
2285	struct uart_state *state = drv->state + line;
2286	struct uart_port *port;
2287
2288	if (!state || !state->uart_port)
 
2289		return;
2290
2291	port = state->uart_port;
2292
2293	if (ch == '\n')
2294		port->ops->poll_put_char(port, '\r');
2295	port->ops->poll_put_char(port, ch);
 
2296}
2297#endif
2298
2299static const struct tty_operations uart_ops = {
 
2300	.open		= uart_open,
2301	.close		= uart_close,
2302	.write		= uart_write,
2303	.put_char	= uart_put_char,
2304	.flush_chars	= uart_flush_chars,
2305	.write_room	= uart_write_room,
2306	.chars_in_buffer= uart_chars_in_buffer,
2307	.flush_buffer	= uart_flush_buffer,
2308	.ioctl		= uart_ioctl,
2309	.throttle	= uart_throttle,
2310	.unthrottle	= uart_unthrottle,
2311	.send_xchar	= uart_send_xchar,
2312	.set_termios	= uart_set_termios,
2313	.set_ldisc	= uart_set_ldisc,
2314	.stop		= uart_stop,
2315	.start		= uart_start,
2316	.hangup		= uart_hangup,
2317	.break_ctl	= uart_break_ctl,
2318	.wait_until_sent= uart_wait_until_sent,
2319#ifdef CONFIG_PROC_FS
2320	.proc_fops	= &uart_proc_fops,
2321#endif
2322	.tiocmget	= uart_tiocmget,
2323	.tiocmset	= uart_tiocmset,
 
 
2324	.get_icount	= uart_get_icount,
2325#ifdef CONFIG_CONSOLE_POLL
2326	.poll_init	= uart_poll_init,
2327	.poll_get_char	= uart_poll_get_char,
2328	.poll_put_char	= uart_poll_put_char,
2329#endif
2330};
2331
2332static const struct tty_port_operations uart_port_ops = {
2333	.carrier_raised = uart_carrier_raised,
2334	.dtr_rts	= uart_dtr_rts,
 
 
2335};
2336
2337/**
2338 *	uart_register_driver - register a driver with the uart core layer
2339 *	@drv: low level driver structure
2340 *
2341 *	Register a uart driver with the core driver.  We in turn register
2342 *	with the tty layer, and initialise the core driver per-port state.
2343 *
2344 *	We have a proc file in /proc/tty/driver which is named after the
2345 *	normal driver.
2346 *
2347 *	drv->port should be NULL, and the per-port structures should be
2348 *	registered using uart_add_one_port after this call has succeeded.
2349 */
2350int uart_register_driver(struct uart_driver *drv)
2351{
2352	struct tty_driver *normal;
2353	int i, retval;
2354
2355	BUG_ON(drv->state);
2356
2357	/*
2358	 * Maybe we should be using a slab cache for this, especially if
2359	 * we have a large number of ports to handle.
2360	 */
2361	drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL);
2362	if (!drv->state)
2363		goto out;
2364
2365	normal = alloc_tty_driver(drv->nr);
2366	if (!normal)
2367		goto out_kfree;
2368
2369	drv->tty_driver = normal;
2370
2371	normal->driver_name	= drv->driver_name;
2372	normal->name		= drv->dev_name;
2373	normal->major		= drv->major;
2374	normal->minor_start	= drv->minor;
2375	normal->type		= TTY_DRIVER_TYPE_SERIAL;
2376	normal->subtype		= SERIAL_TYPE_NORMAL;
2377	normal->init_termios	= tty_std_termios;
2378	normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2379	normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2380	normal->flags		= TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2381	normal->driver_state    = drv;
2382	tty_set_operations(normal, &uart_ops);
2383
2384	/*
2385	 * Initialise the UART state(s).
2386	 */
2387	for (i = 0; i < drv->nr; i++) {
2388		struct uart_state *state = drv->state + i;
2389		struct tty_port *port = &state->port;
2390
2391		tty_port_init(port);
2392		port->ops = &uart_port_ops;
2393	}
2394
2395	retval = tty_register_driver(normal);
2396	if (retval >= 0)
2397		return retval;
2398
2399	for (i = 0; i < drv->nr; i++)
2400		tty_port_destroy(&drv->state[i].port);
2401	put_tty_driver(normal);
2402out_kfree:
2403	kfree(drv->state);
2404out:
2405	return -ENOMEM;
2406}
2407
2408/**
2409 *	uart_unregister_driver - remove a driver from the uart core layer
2410 *	@drv: low level driver structure
2411 *
2412 *	Remove all references to a driver from the core driver.  The low
2413 *	level driver must have removed all its ports via the
2414 *	uart_remove_one_port() if it registered them with uart_add_one_port().
2415 *	(ie, drv->port == NULL)
2416 */
2417void uart_unregister_driver(struct uart_driver *drv)
2418{
2419	struct tty_driver *p = drv->tty_driver;
2420	unsigned int i;
2421
2422	tty_unregister_driver(p);
2423	put_tty_driver(p);
2424	for (i = 0; i < drv->nr; i++)
2425		tty_port_destroy(&drv->state[i].port);
2426	kfree(drv->state);
2427	drv->state = NULL;
2428	drv->tty_driver = NULL;
2429}
2430
2431struct tty_driver *uart_console_device(struct console *co, int *index)
2432{
2433	struct uart_driver *p = co->data;
2434	*index = co->index;
2435	return p->tty_driver;
2436}
 
2437
2438static ssize_t uart_get_attr_uartclk(struct device *dev,
2439	struct device_attribute *attr, char *buf)
2440{
2441	struct serial_struct tmp;
2442	struct tty_port *port = dev_get_drvdata(dev);
2443
2444	uart_get_info(port, &tmp);
2445	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2446}
2447
2448static ssize_t uart_get_attr_type(struct device *dev,
2449	struct device_attribute *attr, char *buf)
2450{
2451	struct serial_struct tmp;
2452	struct tty_port *port = dev_get_drvdata(dev);
2453
2454	uart_get_info(port, &tmp);
2455	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2456}
2457static ssize_t uart_get_attr_line(struct device *dev,
 
2458	struct device_attribute *attr, char *buf)
2459{
2460	struct serial_struct tmp;
2461	struct tty_port *port = dev_get_drvdata(dev);
2462
2463	uart_get_info(port, &tmp);
2464	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2465}
2466
2467static ssize_t uart_get_attr_port(struct device *dev,
2468	struct device_attribute *attr, char *buf)
2469{
2470	struct serial_struct tmp;
2471	struct tty_port *port = dev_get_drvdata(dev);
2472	unsigned long ioaddr;
2473
2474	uart_get_info(port, &tmp);
2475	ioaddr = tmp.port;
2476	if (HIGH_BITS_OFFSET)
2477		ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2478	return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2479}
2480
2481static ssize_t uart_get_attr_irq(struct device *dev,
2482	struct device_attribute *attr, char *buf)
2483{
2484	struct serial_struct tmp;
2485	struct tty_port *port = dev_get_drvdata(dev);
2486
2487	uart_get_info(port, &tmp);
2488	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2489}
2490
2491static ssize_t uart_get_attr_flags(struct device *dev,
2492	struct device_attribute *attr, char *buf)
2493{
2494	struct serial_struct tmp;
2495	struct tty_port *port = dev_get_drvdata(dev);
2496
2497	uart_get_info(port, &tmp);
2498	return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2499}
2500
2501static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2502	struct device_attribute *attr, char *buf)
2503{
2504	struct serial_struct tmp;
2505	struct tty_port *port = dev_get_drvdata(dev);
2506
2507	uart_get_info(port, &tmp);
2508	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2509}
2510
2511
2512static ssize_t uart_get_attr_close_delay(struct device *dev,
2513	struct device_attribute *attr, char *buf)
2514{
2515	struct serial_struct tmp;
2516	struct tty_port *port = dev_get_drvdata(dev);
2517
2518	uart_get_info(port, &tmp);
2519	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2520}
2521
2522
2523static ssize_t uart_get_attr_closing_wait(struct device *dev,
2524	struct device_attribute *attr, char *buf)
2525{
2526	struct serial_struct tmp;
2527	struct tty_port *port = dev_get_drvdata(dev);
2528
2529	uart_get_info(port, &tmp);
2530	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2531}
2532
2533static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2534	struct device_attribute *attr, char *buf)
2535{
2536	struct serial_struct tmp;
2537	struct tty_port *port = dev_get_drvdata(dev);
2538
2539	uart_get_info(port, &tmp);
2540	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2541}
2542
2543static ssize_t uart_get_attr_io_type(struct device *dev,
2544	struct device_attribute *attr, char *buf)
2545{
2546	struct serial_struct tmp;
2547	struct tty_port *port = dev_get_drvdata(dev);
2548
2549	uart_get_info(port, &tmp);
2550	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2551}
2552
2553static ssize_t uart_get_attr_iomem_base(struct device *dev,
2554	struct device_attribute *attr, char *buf)
2555{
2556	struct serial_struct tmp;
2557	struct tty_port *port = dev_get_drvdata(dev);
2558
2559	uart_get_info(port, &tmp);
2560	return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2561}
2562
2563static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2564	struct device_attribute *attr, char *buf)
2565{
2566	struct serial_struct tmp;
2567	struct tty_port *port = dev_get_drvdata(dev);
2568
2569	uart_get_info(port, &tmp);
2570	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
2571}
2572
2573static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2574static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2575static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2576static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2577static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2578static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2579static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2580static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2581static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2582static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2583static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2584static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2585static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2586
2587static struct attribute *tty_dev_attrs[] = {
 
2588	&dev_attr_type.attr,
2589	&dev_attr_line.attr,
2590	&dev_attr_port.attr,
2591	&dev_attr_irq.attr,
2592	&dev_attr_flags.attr,
2593	&dev_attr_xmit_fifo_size.attr,
2594	&dev_attr_uartclk.attr,
2595	&dev_attr_close_delay.attr,
2596	&dev_attr_closing_wait.attr,
2597	&dev_attr_custom_divisor.attr,
2598	&dev_attr_io_type.attr,
2599	&dev_attr_iomem_base.attr,
2600	&dev_attr_iomem_reg_shift.attr,
2601	NULL,
2602	};
 
2603
2604static const struct attribute_group tty_dev_attr_group = {
2605	.attrs = tty_dev_attrs,
2606	};
2607
2608/**
2609 *	uart_add_one_port - attach a driver-defined port structure
2610 *	@drv: pointer to the uart low level driver structure for this port
2611 *	@uport: uart port structure to use for this port.
2612 *
2613 *	This allows the driver to register its own uart_port structure
2614 *	with the core driver.  The main purpose is to allow the low
2615 *	level uart drivers to expand uart_port, rather than having yet
2616 *	more levels of structures.
2617 */
2618int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2619{
2620	struct uart_state *state;
2621	struct tty_port *port;
2622	int ret = 0;
2623	struct device *tty_dev;
2624	int num_groups;
2625
2626	BUG_ON(in_interrupt());
2627
2628	if (uport->line >= drv->nr)
2629		return -EINVAL;
2630
2631	state = drv->state + uport->line;
2632	port = &state->port;
2633
2634	mutex_lock(&port_mutex);
2635	mutex_lock(&port->mutex);
2636	if (state->uart_port) {
2637		ret = -EINVAL;
2638		goto out;
2639	}
2640
2641	/* Link the port to the driver state table and vice versa */
 
 
2642	state->uart_port = uport;
2643	uport->state = state;
2644
2645	state->pm_state = UART_PM_STATE_UNDEFINED;
2646	uport->cons = drv->cons;
2647	uport->minor = drv->tty_driver->minor_start + uport->line;
 
 
 
 
 
 
2648
2649	/*
2650	 * If this port is a console, then the spinlock is already
2651	 * initialised.
2652	 */
2653	if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2654		spin_lock_init(&uport->lock);
2655		lockdep_set_class(&uport->lock, &port_lock_key);
2656	}
2657	if (uport->cons && uport->dev)
2658		of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2659
 
2660	uart_configure_port(drv, state, uport);
2661
 
 
2662	num_groups = 2;
2663	if (uport->attr_group)
2664		num_groups++;
2665
2666	uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2667				    GFP_KERNEL);
2668	if (!uport->tty_groups) {
2669		ret = -ENOMEM;
2670		goto out;
2671	}
2672	uport->tty_groups[0] = &tty_dev_attr_group;
2673	if (uport->attr_group)
2674		uport->tty_groups[1] = uport->attr_group;
2675
2676	/*
2677	 * Register the port whether it's detected or not.  This allows
2678	 * setserial to be used to alter this port's parameters.
2679	 */
2680	tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
2681			uport->line, uport->dev, port, uport->tty_groups);
2682	if (likely(!IS_ERR(tty_dev))) {
2683		device_set_wakeup_capable(tty_dev, 1);
2684	} else {
2685		dev_err(uport->dev, "Cannot register tty device on line %d\n",
2686		       uport->line);
2687	}
2688
2689	/*
2690	 * Ensure UPF_DEAD is not set.
2691	 */
2692	uport->flags &= ~UPF_DEAD;
2693
2694 out:
2695	mutex_unlock(&port->mutex);
2696	mutex_unlock(&port_mutex);
2697
2698	return ret;
2699}
2700
2701/**
2702 *	uart_remove_one_port - detach a driver defined port structure
2703 *	@drv: pointer to the uart low level driver structure for this port
2704 *	@uport: uart port structure for this port
2705 *
2706 *	This unhooks (and hangs up) the specified port structure from the
2707 *	core driver.  No further calls will be made to the low-level code
2708 *	for this port.
2709 */
2710int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
2711{
2712	struct uart_state *state = drv->state + uport->line;
2713	struct tty_port *port = &state->port;
 
2714	struct tty_struct *tty;
2715	int ret = 0;
2716
2717	BUG_ON(in_interrupt());
2718
2719	if (state->uart_port != uport)
2720		dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2721			state->uart_port, uport);
2722
2723	mutex_lock(&port_mutex);
2724
2725	/*
2726	 * Mark the port "dead" - this prevents any opens from
2727	 * succeeding while we shut down the port.
2728	 */
2729	mutex_lock(&port->mutex);
2730	if (!state->uart_port) {
 
 
 
 
 
2731		mutex_unlock(&port->mutex);
2732		ret = -EINVAL;
2733		goto out;
2734	}
2735	uport->flags |= UPF_DEAD;
2736	mutex_unlock(&port->mutex);
2737
2738	/*
2739	 * Remove the devices from the tty layer
2740	 */
2741	tty_unregister_device(drv->tty_driver, uport->line);
2742
2743	tty = tty_port_tty_get(port);
2744	if (tty) {
2745		tty_vhangup(port->tty);
2746		tty_kref_put(tty);
2747	}
2748
2749	/*
2750	 * If the port is used as a console, unregister it
2751	 */
2752	if (uart_console(uport))
2753		unregister_console(uport->cons);
2754
2755	/*
2756	 * Free the port IO and memory resources, if any.
2757	 */
2758	if (uport->type != PORT_UNKNOWN)
2759		uport->ops->release_port(uport);
2760	kfree(uport->tty_groups);
 
2761
2762	/*
2763	 * Indicate that there isn't a port here anymore.
2764	 */
2765	uport->type = PORT_UNKNOWN;
2766
 
 
 
2767	state->uart_port = NULL;
 
2768out:
2769	mutex_unlock(&port_mutex);
2770
2771	return ret;
2772}
2773
2774/*
2775 *	Are the two ports equivalent?
2776 */
2777int uart_match_port(struct uart_port *port1, struct uart_port *port2)
2778{
2779	if (port1->iotype != port2->iotype)
2780		return 0;
2781
2782	switch (port1->iotype) {
2783	case UPIO_PORT:
2784		return (port1->iobase == port2->iobase);
2785	case UPIO_HUB6:
2786		return (port1->iobase == port2->iobase) &&
2787		       (port1->hub6   == port2->hub6);
2788	case UPIO_MEM:
2789	case UPIO_MEM16:
2790	case UPIO_MEM32:
2791	case UPIO_MEM32BE:
2792	case UPIO_AU:
2793	case UPIO_TSI:
2794		return (port1->mapbase == port2->mapbase);
2795	}
2796	return 0;
2797}
2798EXPORT_SYMBOL(uart_match_port);
2799
2800/**
2801 *	uart_handle_dcd_change - handle a change of carrier detect state
2802 *	@uport: uart_port structure for the open port
2803 *	@status: new carrier detect status, nonzero if active
2804 *
2805 *	Caller must hold uport->lock
2806 */
2807void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2808{
2809	struct tty_port *port = &uport->state->port;
2810	struct tty_struct *tty = port->tty;
2811	struct tty_ldisc *ld;
2812
2813	lockdep_assert_held_once(&uport->lock);
2814
2815	if (tty) {
2816		ld = tty_ldisc_ref(tty);
2817		if (ld) {
2818			if (ld->ops->dcd_change)
2819				ld->ops->dcd_change(tty, status);
2820			tty_ldisc_deref(ld);
2821		}
2822	}
2823
2824	uport->icount.dcd++;
2825
2826	if (uart_dcd_enabled(uport)) {
2827		if (status)
2828			wake_up_interruptible(&port->open_wait);
2829		else if (tty)
2830			tty_hangup(tty);
2831	}
2832}
2833EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
2834
2835/**
2836 *	uart_handle_cts_change - handle a change of clear-to-send state
2837 *	@uport: uart_port structure for the open port
2838 *	@status: new clear to send status, nonzero if active
2839 *
2840 *	Caller must hold uport->lock
2841 */
2842void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
2843{
2844	lockdep_assert_held_once(&uport->lock);
2845
2846	uport->icount.cts++;
2847
2848	if (uart_softcts_mode(uport)) {
2849		if (uport->hw_stopped) {
2850			if (status) {
2851				uport->hw_stopped = 0;
2852				uport->ops->start_tx(uport);
2853				uart_write_wakeup(uport);
2854			}
2855		} else {
2856			if (!status) {
2857				uport->hw_stopped = 1;
2858				uport->ops->stop_tx(uport);
2859			}
2860		}
2861
2862	}
2863}
2864EXPORT_SYMBOL_GPL(uart_handle_cts_change);
2865
2866/**
2867 * uart_insert_char - push a char to the uart layer
2868 *
2869 * User is responsible to call tty_flip_buffer_push when they are done with
2870 * insertion.
2871 *
2872 * @port: corresponding port
2873 * @status: state of the serial port RX buffer (LSR for 8250)
2874 * @overrun: mask of overrun bits in @status
2875 * @ch: character to push
2876 * @flag: flag for the character (see TTY_NORMAL and friends)
2877 */
2878void uart_insert_char(struct uart_port *port, unsigned int status,
2879		 unsigned int overrun, unsigned int ch, unsigned int flag)
2880{
2881	struct tty_port *tport = &port->state->port;
2882
2883	if ((status & port->ignore_status_mask & ~overrun) == 0)
2884		if (tty_insert_flip_char(tport, ch, flag) == 0)
2885			++port->icount.buf_overrun;
2886
2887	/*
2888	 * Overrun is special.  Since it's reported immediately,
2889	 * it doesn't affect the current character.
2890	 */
2891	if (status & ~port->ignore_status_mask & overrun)
2892		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
2893			++port->icount.buf_overrun;
2894}
2895EXPORT_SYMBOL_GPL(uart_insert_char);
2896
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2897EXPORT_SYMBOL(uart_write_wakeup);
2898EXPORT_SYMBOL(uart_register_driver);
2899EXPORT_SYMBOL(uart_unregister_driver);
2900EXPORT_SYMBOL(uart_suspend_port);
2901EXPORT_SYMBOL(uart_resume_port);
2902EXPORT_SYMBOL(uart_add_one_port);
2903EXPORT_SYMBOL(uart_remove_one_port);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2904
2905MODULE_DESCRIPTION("Serial driver core");
2906MODULE_LICENSE("GPL");