1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 *  Driver core for serial ports
   4 *
   5 *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
   6 *
   7 *  Copyright 1999 ARM Limited
   8 *  Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
   9 */
  10#include <linux/module.h>
  11#include <linux/tty.h>
  12#include <linux/tty_flip.h>
  13#include <linux/slab.h>
  14#include <linux/sched/signal.h>
  15#include <linux/init.h>
  16#include <linux/console.h>
 
 
  17#include <linux/of.h>
 
  18#include <linux/proc_fs.h>
  19#include <linux/seq_file.h>
  20#include <linux/device.h>
  21#include <linux/serial.h> /* for serial_state and serial_icounter_struct */
  22#include <linux/serial_core.h>
 
  23#include <linux/delay.h>
  24#include <linux/mutex.h>
 
  25#include <linux/security.h>
  26
  27#include <linux/irq.h>
  28#include <linux/uaccess.h>
  29
 
 
  30/*
  31 * This is used to lock changes in serial line configuration.
  32 */
  33static DEFINE_MUTEX(port_mutex);
  34
  35/*
  36 * lockdep: port->lock is initialized in two places, but we
  37 *          want only one lock-class:
  38 */
  39static struct lock_class_key port_lock_key;
  40
  41#define HIGH_BITS_OFFSET	((sizeof(long)-sizeof(int))*8)
  42
  43static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
  44					struct ktermios *old_termios);
  45static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
 
 
  46static void uart_change_pm(struct uart_state *state,
  47			   enum uart_pm_state pm_state);
  48
  49static void uart_port_shutdown(struct tty_port *port);
  50
  51static int uart_dcd_enabled(struct uart_port *uport)
  52{
  53	return !!(uport->status & UPSTAT_DCD_ENABLE);
  54}
  55
  56static inline struct uart_port *uart_port_ref(struct uart_state *state)
  57{
  58	if (atomic_add_unless(&state->refcount, 1, 0))
  59		return state->uart_port;
  60	return NULL;
  61}
  62
  63static inline void uart_port_deref(struct uart_port *uport)
  64{
  65	if (atomic_dec_and_test(&uport->state->refcount))
  66		wake_up(&uport->state->remove_wait);
  67}
  68
  69#define uart_port_lock(state, flags)					\
  70	({								\
  71		struct uart_port *__uport = uart_port_ref(state);	\
  72		if (__uport)						\
  73			spin_lock_irqsave(&__uport->lock, flags);	\
  74		__uport;						\
  75	})
  76
  77#define uart_port_unlock(uport, flags)					\
  78	({								\
  79		struct uart_port *__uport = uport;			\
  80		if (__uport) {						\
  81			spin_unlock_irqrestore(&__uport->lock, flags);	\
  82			uart_port_deref(__uport);			\
  83		}							\
  84	})
  85
  86static inline struct uart_port *uart_port_check(struct uart_state *state)
  87{
  88	lockdep_assert_held(&state->port.mutex);
  89	return state->uart_port;
  90}
  91
  92/*
  93 * This routine is used by the interrupt handler to schedule processing in
  94 * the software interrupt portion of the driver.
 
 
 
 
 
 
 
  95 */
  96void uart_write_wakeup(struct uart_port *port)
  97{
  98	struct uart_state *state = port->state;
  99	/*
 100	 * This means you called this function _after_ the port was
 101	 * closed.  No cookie for you.
 102	 */
 103	BUG_ON(!state);
 104	tty_port_tty_wakeup(&state->port);
 105}
 
 106
 107static void uart_stop(struct tty_struct *tty)
 108{
 109	struct uart_state *state = tty->driver_data;
 110	struct uart_port *port;
 111	unsigned long flags;
 112
 113	port = uart_port_lock(state, flags);
 114	if (port)
 115		port->ops->stop_tx(port);
 116	uart_port_unlock(port, flags);
 117}
 118
 119static void __uart_start(struct tty_struct *tty)
 120{
 121	struct uart_state *state = tty->driver_data;
 122	struct uart_port *port = state->uart_port;
 
 
 123
 124	if (port && !uart_tx_stopped(port))
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 125		port->ops->start_tx(port);
 
 
 126}
 127
 128static void uart_start(struct tty_struct *tty)
 129{
 130	struct uart_state *state = tty->driver_data;
 131	struct uart_port *port;
 132	unsigned long flags;
 133
 134	port = uart_port_lock(state, flags);
 135	__uart_start(tty);
 136	uart_port_unlock(port, flags);
 137}
 138
 139static void
 140uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
 141{
 142	unsigned long flags;
 143	unsigned int old;
 144
 145	spin_lock_irqsave(&port->lock, flags);
 146	old = port->mctrl;
 147	port->mctrl = (old & ~clear) | set;
 148	if (old != port->mctrl)
 149		port->ops->set_mctrl(port, port->mctrl);
 150	spin_unlock_irqrestore(&port->lock, flags);
 151}
 152
 153#define uart_set_mctrl(port, set)	uart_update_mctrl(port, set, 0)
 154#define uart_clear_mctrl(port, clear)	uart_update_mctrl(port, 0, clear)
 155
 156static void uart_port_dtr_rts(struct uart_port *uport, int raise)
 157{
 158	int rs485_on = uport->rs485_config &&
 159		(uport->rs485.flags & SER_RS485_ENABLED);
 160	int RTS_after_send = !!(uport->rs485.flags & SER_RS485_RTS_AFTER_SEND);
 161
 162	if (raise) {
 163		if (rs485_on && !RTS_after_send) {
 164			uart_set_mctrl(uport, TIOCM_DTR);
 165			uart_clear_mctrl(uport, TIOCM_RTS);
 166		} else {
 167			uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
 168		}
 169	} else {
 170		unsigned int clear = TIOCM_DTR;
 
 
 
 
 
 
 
 
 
 
 171
 172		clear |= (!rs485_on || !RTS_after_send) ? TIOCM_RTS : 0;
 173		uart_clear_mctrl(uport, clear);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 174	}
 
 175}
 176
 177/*
 178 * Startup the port.  This will be called once per open.  All calls
 179 * will be serialised by the per-port mutex.
 180 */
 181static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
 182		int init_hw)
 183{
 184	struct uart_port *uport = uart_port_check(state);
 
 185	unsigned long page;
 186	unsigned long flags = 0;
 187	int retval = 0;
 188
 189	if (uport->type == PORT_UNKNOWN)
 190		return 1;
 191
 192	/*
 193	 * Make sure the device is in D0 state.
 194	 */
 195	uart_change_pm(state, UART_PM_STATE_ON);
 196
 197	/*
 198	 * Initialise and allocate the transmit and temporary
 199	 * buffer.
 200	 */
 201	page = get_zeroed_page(GFP_KERNEL);
 202	if (!page)
 203		return -ENOMEM;
 204
 205	uart_port_lock(state, flags);
 206	if (!state->xmit.buf) {
 207		state->xmit.buf = (unsigned char *) page;
 208		uart_circ_clear(&state->xmit);
 209		uart_port_unlock(uport, flags);
 210	} else {
 211		uart_port_unlock(uport, flags);
 212		/*
 213		 * Do not free() the page under the port lock, see
 214		 * uart_shutdown().
 215		 */
 216		free_page(page);
 217	}
 218
 219	retval = uport->ops->startup(uport);
 220	if (retval == 0) {
 221		if (uart_console(uport) && uport->cons->cflag) {
 222			tty->termios.c_cflag = uport->cons->cflag;
 
 
 223			uport->cons->cflag = 0;
 
 
 224		}
 225		/*
 226		 * Initialise the hardware port settings.
 227		 */
 228		uart_change_speed(tty, state, NULL);
 229
 230		/*
 231		 * Setup the RTS and DTR signals once the
 232		 * port is open and ready to respond.
 233		 */
 234		if (init_hw && C_BAUD(tty))
 235			uart_port_dtr_rts(uport, 1);
 236	}
 237
 238	/*
 239	 * This is to allow setserial on this port. People may want to set
 240	 * port/irq/type and then reconfigure the port properly if it failed
 241	 * now.
 242	 */
 243	if (retval && capable(CAP_SYS_ADMIN))
 244		return 1;
 245
 246	return retval;
 247}
 248
 249static int uart_startup(struct tty_struct *tty, struct uart_state *state,
 250		int init_hw)
 251{
 252	struct tty_port *port = &state->port;
 253	int retval;
 254
 255	if (tty_port_initialized(port))
 256		return 0;
 257
 258	retval = uart_port_startup(tty, state, init_hw);
 259	if (retval)
 260		set_bit(TTY_IO_ERROR, &tty->flags);
 261
 262	return retval;
 263}
 264
 265/*
 266 * This routine will shutdown a serial port; interrupts are disabled, and
 267 * DTR is dropped if the hangup on close termio flag is on.  Calls to
 268 * uart_shutdown are serialised by the per-port semaphore.
 269 *
 270 * uport == NULL if uart_port has already been removed
 271 */
 272static void uart_shutdown(struct tty_struct *tty, struct uart_state *state)
 273{
 274	struct uart_port *uport = uart_port_check(state);
 275	struct tty_port *port = &state->port;
 276	unsigned long flags = 0;
 277	char *xmit_buf = NULL;
 278
 279	/*
 280	 * Set the TTY IO error marker
 281	 */
 282	if (tty)
 283		set_bit(TTY_IO_ERROR, &tty->flags);
 284
 285	if (tty_port_initialized(port)) {
 286		tty_port_set_initialized(port, 0);
 287
 288		/*
 289		 * Turn off DTR and RTS early.
 290		 */
 291		if (uport && uart_console(uport) && tty)
 292			uport->cons->cflag = tty->termios.c_cflag;
 
 
 
 293
 294		if (!tty || C_HUPCL(tty))
 295			uart_port_dtr_rts(uport, 0);
 296
 297		uart_port_shutdown(port);
 298	}
 299
 300	/*
 301	 * It's possible for shutdown to be called after suspend if we get
 302	 * a DCD drop (hangup) at just the right time.  Clear suspended bit so
 303	 * we don't try to resume a port that has been shutdown.
 304	 */
 305	tty_port_set_suspended(port, 0);
 306
 307	/*
 308	 * Do not free() the transmit buffer page under the port lock since
 309	 * this can create various circular locking scenarios. For instance,
 310	 * console driver may need to allocate/free a debug object, which
 311	 * can endup in printk() recursion.
 312	 */
 313	uart_port_lock(state, flags);
 314	xmit_buf = state->xmit.buf;
 315	state->xmit.buf = NULL;
 316	uart_port_unlock(uport, flags);
 317
 318	if (xmit_buf)
 319		free_page((unsigned long)xmit_buf);
 320}
 321
 322/**
 323 *	uart_update_timeout - update per-port FIFO timeout.
 324 *	@port:  uart_port structure describing the port
 325 *	@cflag: termios cflag value
 326 *	@baud:  speed of the port
 
 
 
 
 327 *
 328 *	Set the port FIFO timeout value.  The @cflag value should
 329 *	reflect the actual hardware settings.
 330 */
 331void
 332uart_update_timeout(struct uart_port *port, unsigned int cflag,
 333		    unsigned int baud)
 334{
 335	unsigned int bits;
 336
 337	/* byte size and parity */
 338	switch (cflag & CSIZE) {
 339	case CS5:
 340		bits = 7;
 341		break;
 342	case CS6:
 343		bits = 8;
 344		break;
 345	case CS7:
 346		bits = 9;
 347		break;
 348	default:
 349		bits = 10;
 350		break; /* CS8 */
 351	}
 352
 353	if (cflag & CSTOPB)
 354		bits++;
 355	if (cflag & PARENB)
 356		bits++;
 357
 358	/*
 359	 * The total number of bits to be transmitted in the fifo.
 360	 */
 361	bits = bits * port->fifosize;
 362
 363	/*
 364	 * Figure the timeout to send the above number of bits.
 365	 * Add .02 seconds of slop
 366	 */
 367	port->timeout = (HZ * bits) / baud + HZ/50;
 368}
 369
 370EXPORT_SYMBOL(uart_update_timeout);
 371
 372/**
 373 *	uart_get_baud_rate - return baud rate for a particular port
 374 *	@port: uart_port structure describing the port in question.
 375 *	@termios: desired termios settings.
 376 *	@old: old termios (or NULL)
 377 *	@min: minimum acceptable baud rate
 378 *	@max: maximum acceptable baud rate
 379 *
 380 *	Decode the termios structure into a numeric baud rate,
 381 *	taking account of the magic 38400 baud rate (with spd_*
 382 *	flags), and mapping the %B0 rate to 9600 baud.
 383 *
 384 *	If the new baud rate is invalid, try the old termios setting.
 385 *	If it's still invalid, we try 9600 baud.
 386 *
 387 *	Update the @termios structure to reflect the baud rate
 388 *	we're actually going to be using. Don't do this for the case
 389 *	where B0 is requested ("hang up").
 
 
 390 */
 391unsigned int
 392uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
 393		   struct ktermios *old, unsigned int min, unsigned int max)
 394{
 395	unsigned int try;
 396	unsigned int baud;
 397	unsigned int altbaud;
 398	int hung_up = 0;
 399	upf_t flags = port->flags & UPF_SPD_MASK;
 400
 401	switch (flags) {
 402	case UPF_SPD_HI:
 403		altbaud = 57600;
 404		break;
 405	case UPF_SPD_VHI:
 406		altbaud = 115200;
 407		break;
 408	case UPF_SPD_SHI:
 409		altbaud = 230400;
 410		break;
 411	case UPF_SPD_WARP:
 412		altbaud = 460800;
 413		break;
 414	default:
 415		altbaud = 38400;
 416		break;
 417	}
 418
 419	for (try = 0; try < 2; try++) {
 420		baud = tty_termios_baud_rate(termios);
 421
 422		/*
 423		 * The spd_hi, spd_vhi, spd_shi, spd_warp kludge...
 424		 * Die! Die! Die!
 425		 */
 426		if (try == 0 && baud == 38400)
 427			baud = altbaud;
 428
 429		/*
 430		 * Special case: B0 rate.
 431		 */
 432		if (baud == 0) {
 433			hung_up = 1;
 434			baud = 9600;
 435		}
 436
 437		if (baud >= min && baud <= max)
 438			return baud;
 439
 440		/*
 441		 * Oops, the quotient was zero.  Try again with
 442		 * the old baud rate if possible.
 443		 */
 444		termios->c_cflag &= ~CBAUD;
 445		if (old) {
 446			baud = tty_termios_baud_rate(old);
 447			if (!hung_up)
 448				tty_termios_encode_baud_rate(termios,
 449								baud, baud);
 450			old = NULL;
 451			continue;
 452		}
 453
 454		/*
 455		 * As a last resort, if the range cannot be met then clip to
 456		 * the nearest chip supported rate.
 457		 */
 458		if (!hung_up) {
 459			if (baud <= min)
 460				tty_termios_encode_baud_rate(termios,
 461							min + 1, min + 1);
 462			else
 463				tty_termios_encode_baud_rate(termios,
 464							max - 1, max - 1);
 465		}
 466	}
 467	/* Should never happen */
 468	WARN_ON(1);
 469	return 0;
 470}
 471
 472EXPORT_SYMBOL(uart_get_baud_rate);
 473
 474/**
 475 *	uart_get_divisor - return uart clock divisor
 476 *	@port: uart_port structure describing the port.
 477 *	@baud: desired baud rate
 478 *
 479 *	Calculate the uart clock divisor for the port.
 
 
 
 
 
 
 480 */
 481unsigned int
 482uart_get_divisor(struct uart_port *port, unsigned int baud)
 483{
 484	unsigned int quot;
 485
 486	/*
 487	 * Old custom speed handling.
 488	 */
 489	if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
 490		quot = port->custom_divisor;
 491	else
 492		quot = DIV_ROUND_CLOSEST(port->uartclk, 16 * baud);
 493
 494	return quot;
 495}
 496
 497EXPORT_SYMBOL(uart_get_divisor);
 498
 499/* Caller holds port mutex */
 500static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
 501					struct ktermios *old_termios)
 502{
 503	struct uart_port *uport = uart_port_check(state);
 504	struct ktermios *termios;
 505	int hw_stopped;
 506
 507	/*
 508	 * If we have no tty, termios, or the port does not exist,
 509	 * then we can't set the parameters for this port.
 510	 */
 511	if (!tty || uport->type == PORT_UNKNOWN)
 512		return;
 513
 514	termios = &tty->termios;
 515	uport->ops->set_termios(uport, termios, old_termios);
 516
 517	/*
 518	 * Set modem status enables based on termios cflag
 519	 */
 520	spin_lock_irq(&uport->lock);
 521	if (termios->c_cflag & CRTSCTS)
 522		uport->status |= UPSTAT_CTS_ENABLE;
 523	else
 524		uport->status &= ~UPSTAT_CTS_ENABLE;
 525
 526	if (termios->c_cflag & CLOCAL)
 527		uport->status &= ~UPSTAT_DCD_ENABLE;
 528	else
 529		uport->status |= UPSTAT_DCD_ENABLE;
 530
 531	/* reset sw-assisted CTS flow control based on (possibly) new mode */
 532	hw_stopped = uport->hw_stopped;
 533	uport->hw_stopped = uart_softcts_mode(uport) &&
 534				!(uport->ops->get_mctrl(uport) & TIOCM_CTS);
 535	if (uport->hw_stopped) {
 536		if (!hw_stopped)
 537			uport->ops->stop_tx(uport);
 538	} else {
 539		if (hw_stopped)
 540			__uart_start(tty);
 541	}
 542	spin_unlock_irq(&uport->lock);
 543}
 544
 545static int uart_put_char(struct tty_struct *tty, unsigned char c)
 546{
 547	struct uart_state *state = tty->driver_data;
 548	struct uart_port *port;
 549	struct circ_buf *circ;
 550	unsigned long flags;
 551	int ret = 0;
 552
 553	circ = &state->xmit;
 554	port = uart_port_lock(state, flags);
 555	if (!circ->buf) {
 556		uart_port_unlock(port, flags);
 557		return 0;
 558	}
 559
 560	if (port && uart_circ_chars_free(circ) != 0) {
 561		circ->buf[circ->head] = c;
 562		circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
 563		ret = 1;
 564	}
 565	uart_port_unlock(port, flags);
 566	return ret;
 567}
 568
 569static void uart_flush_chars(struct tty_struct *tty)
 570{
 571	uart_start(tty);
 572}
 573
 574static int uart_write(struct tty_struct *tty,
 575					const unsigned char *buf, int count)
 576{
 577	struct uart_state *state = tty->driver_data;
 578	struct uart_port *port;
 579	struct circ_buf *circ;
 580	unsigned long flags;
 581	int c, ret = 0;
 582
 583	/*
 584	 * This means you called this function _after_ the port was
 585	 * closed.  No cookie for you.
 586	 */
 587	if (!state) {
 588		WARN_ON(1);
 589		return -EL3HLT;
 590	}
 591
 592	port = uart_port_lock(state, flags);
 593	circ = &state->xmit;
 594	if (!circ->buf) {
 595		uart_port_unlock(port, flags);
 596		return 0;
 597	}
 598
 599	while (port) {
 600		c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
 601		if (count < c)
 602			c = count;
 603		if (c <= 0)
 604			break;
 605		memcpy(circ->buf + circ->head, buf, c);
 606		circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
 607		buf += c;
 608		count -= c;
 609		ret += c;
 610	}
 611
 612	__uart_start(tty);
 613	uart_port_unlock(port, flags);
 614	return ret;
 615}
 616
 617static int uart_write_room(struct tty_struct *tty)
 618{
 619	struct uart_state *state = tty->driver_data;
 620	struct uart_port *port;
 621	unsigned long flags;
 622	int ret;
 623
 624	port = uart_port_lock(state, flags);
 625	ret = uart_circ_chars_free(&state->xmit);
 626	uart_port_unlock(port, flags);
 627	return ret;
 628}
 629
 630static int uart_chars_in_buffer(struct tty_struct *tty)
 631{
 632	struct uart_state *state = tty->driver_data;
 633	struct uart_port *port;
 634	unsigned long flags;
 635	int ret;
 636
 637	port = uart_port_lock(state, flags);
 638	ret = uart_circ_chars_pending(&state->xmit);
 639	uart_port_unlock(port, flags);
 640	return ret;
 641}
 642
 643static void uart_flush_buffer(struct tty_struct *tty)
 644{
 645	struct uart_state *state = tty->driver_data;
 646	struct uart_port *port;
 647	unsigned long flags;
 648
 649	/*
 650	 * This means you called this function _after_ the port was
 651	 * closed.  No cookie for you.
 652	 */
 653	if (!state) {
 654		WARN_ON(1);
 655		return;
 656	}
 657
 658	pr_debug("uart_flush_buffer(%d) called\n", tty->index);
 659
 660	port = uart_port_lock(state, flags);
 661	if (!port)
 662		return;
 663	uart_circ_clear(&state->xmit);
 664	if (port->ops->flush_buffer)
 665		port->ops->flush_buffer(port);
 666	uart_port_unlock(port, flags);
 667	tty_port_tty_wakeup(&state->port);
 668}
 669
 670/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 671 * This function is used to send a high-priority XON/XOFF character to
 672 * the device
 673 */
 674static void uart_send_xchar(struct tty_struct *tty, char ch)
 675{
 676	struct uart_state *state = tty->driver_data;
 677	struct uart_port *port;
 678	unsigned long flags;
 679
 680	port = uart_port_ref(state);
 681	if (!port)
 682		return;
 683
 684	if (port->ops->send_xchar)
 685		port->ops->send_xchar(port, ch);
 686	else {
 687		spin_lock_irqsave(&port->lock, flags);
 688		port->x_char = ch;
 689		if (ch)
 690			port->ops->start_tx(port);
 691		spin_unlock_irqrestore(&port->lock, flags);
 692	}
 693	uart_port_deref(port);
 694}
 695
 696static void uart_throttle(struct tty_struct *tty)
 697{
 698	struct uart_state *state = tty->driver_data;
 699	upstat_t mask = UPSTAT_SYNC_FIFO;
 700	struct uart_port *port;
 701
 702	port = uart_port_ref(state);
 703	if (!port)
 704		return;
 705
 706	if (I_IXOFF(tty))
 707		mask |= UPSTAT_AUTOXOFF;
 708	if (C_CRTSCTS(tty))
 709		mask |= UPSTAT_AUTORTS;
 710
 711	if (port->status & mask) {
 712		port->ops->throttle(port);
 713		mask &= ~port->status;
 714	}
 715
 716	if (mask & UPSTAT_AUTORTS)
 717		uart_clear_mctrl(port, TIOCM_RTS);
 718
 719	if (mask & UPSTAT_AUTOXOFF)
 720		uart_send_xchar(tty, STOP_CHAR(tty));
 721
 722	uart_port_deref(port);
 723}
 724
 725static void uart_unthrottle(struct tty_struct *tty)
 726{
 727	struct uart_state *state = tty->driver_data;
 728	upstat_t mask = UPSTAT_SYNC_FIFO;
 729	struct uart_port *port;
 730
 731	port = uart_port_ref(state);
 732	if (!port)
 733		return;
 734
 735	if (I_IXOFF(tty))
 736		mask |= UPSTAT_AUTOXOFF;
 737	if (C_CRTSCTS(tty))
 738		mask |= UPSTAT_AUTORTS;
 739
 740	if (port->status & mask) {
 741		port->ops->unthrottle(port);
 742		mask &= ~port->status;
 743	}
 744
 745	if (mask & UPSTAT_AUTORTS)
 746		uart_set_mctrl(port, TIOCM_RTS);
 747
 748	if (mask & UPSTAT_AUTOXOFF)
 749		uart_send_xchar(tty, START_CHAR(tty));
 750
 751	uart_port_deref(port);
 752}
 753
 754static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo)
 755{
 756	struct uart_state *state = container_of(port, struct uart_state, port);
 757	struct uart_port *uport;
 758	int ret = -ENODEV;
 759
 760	memset(retinfo, 0, sizeof(*retinfo));
 
 761
 762	/*
 763	 * Ensure the state we copy is consistent and no hardware changes
 764	 * occur as we go
 765	 */
 766	mutex_lock(&port->mutex);
 767	uport = uart_port_check(state);
 768	if (!uport)
 769		goto out;
 770
 771	retinfo->type	    = uport->type;
 772	retinfo->line	    = uport->line;
 773	retinfo->port	    = uport->iobase;
 774	if (HIGH_BITS_OFFSET)
 775		retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET;
 776	retinfo->irq		    = uport->irq;
 777	retinfo->flags	    = (__force int)uport->flags;
 778	retinfo->xmit_fifo_size  = uport->fifosize;
 779	retinfo->baud_base	    = uport->uartclk / 16;
 780	retinfo->close_delay	    = jiffies_to_msecs(port->close_delay) / 10;
 781	retinfo->closing_wait    = port->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
 782				ASYNC_CLOSING_WAIT_NONE :
 783				jiffies_to_msecs(port->closing_wait) / 10;
 784	retinfo->custom_divisor  = uport->custom_divisor;
 785	retinfo->hub6	    = uport->hub6;
 786	retinfo->io_type         = uport->iotype;
 787	retinfo->iomem_reg_shift = uport->regshift;
 788	retinfo->iomem_base      = (void *)(unsigned long)uport->mapbase;
 789
 790	ret = 0;
 791out:
 792	mutex_unlock(&port->mutex);
 793	return ret;
 794}
 795
 796static int uart_get_info_user(struct tty_struct *tty,
 797			 struct serial_struct *ss)
 798{
 799	struct uart_state *state = tty->driver_data;
 800	struct tty_port *port = &state->port;
 801
 802	return uart_get_info(port, ss) < 0 ? -EIO : 0;
 803}
 804
 805static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
 806			 struct uart_state *state,
 807			 struct serial_struct *new_info)
 808{
 809	struct uart_port *uport = uart_port_check(state);
 810	unsigned long new_port;
 811	unsigned int change_irq, change_port, closing_wait;
 812	unsigned int old_custom_divisor, close_delay;
 813	upf_t old_flags, new_flags;
 814	int retval = 0;
 815
 816	if (!uport)
 817		return -EIO;
 818
 819	new_port = new_info->port;
 820	if (HIGH_BITS_OFFSET)
 821		new_port += (unsigned long) new_info->port_high << HIGH_BITS_OFFSET;
 822
 823	new_info->irq = irq_canonicalize(new_info->irq);
 824	close_delay = msecs_to_jiffies(new_info->close_delay * 10);
 825	closing_wait = new_info->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
 826			ASYNC_CLOSING_WAIT_NONE :
 827			msecs_to_jiffies(new_info->closing_wait * 10);
 828
 829
 830	change_irq  = !(uport->flags & UPF_FIXED_PORT)
 831		&& new_info->irq != uport->irq;
 832
 833	/*
 834	 * Since changing the 'type' of the port changes its resource
 835	 * allocations, we should treat type changes the same as
 836	 * IO port changes.
 837	 */
 838	change_port = !(uport->flags & UPF_FIXED_PORT)
 839		&& (new_port != uport->iobase ||
 840		    (unsigned long)new_info->iomem_base != uport->mapbase ||
 841		    new_info->hub6 != uport->hub6 ||
 842		    new_info->io_type != uport->iotype ||
 843		    new_info->iomem_reg_shift != uport->regshift ||
 844		    new_info->type != uport->type);
 845
 846	old_flags = uport->flags;
 847	new_flags = (__force upf_t)new_info->flags;
 848	old_custom_divisor = uport->custom_divisor;
 849
 850	if (!capable(CAP_SYS_ADMIN)) {
 851		retval = -EPERM;
 852		if (change_irq || change_port ||
 853		    (new_info->baud_base != uport->uartclk / 16) ||
 854		    (close_delay != port->close_delay) ||
 855		    (closing_wait != port->closing_wait) ||
 856		    (new_info->xmit_fifo_size &&
 857		     new_info->xmit_fifo_size != uport->fifosize) ||
 858		    (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
 859			goto exit;
 860		uport->flags = ((uport->flags & ~UPF_USR_MASK) |
 861			       (new_flags & UPF_USR_MASK));
 862		uport->custom_divisor = new_info->custom_divisor;
 863		goto check_and_exit;
 864	}
 865
 866	retval = security_locked_down(LOCKDOWN_TIOCSSERIAL);
 867	if (retval && (change_irq || change_port))
 868		goto exit;
 
 
 869
 870	/*
 871	 * Ask the low level driver to verify the settings.
 872	 */
 873	if (uport->ops->verify_port)
 874		retval = uport->ops->verify_port(uport, new_info);
 875
 876	if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) ||
 877	    (new_info->baud_base < 9600))
 878		retval = -EINVAL;
 879
 880	if (retval)
 881		goto exit;
 882
 883	if (change_port || change_irq) {
 884		retval = -EBUSY;
 885
 886		/*
 887		 * Make sure that we are the sole user of this port.
 888		 */
 889		if (tty_port_users(port) > 1)
 890			goto exit;
 891
 892		/*
 893		 * We need to shutdown the serial port at the old
 894		 * port/type/irq combination.
 895		 */
 896		uart_shutdown(tty, state);
 897	}
 898
 899	if (change_port) {
 900		unsigned long old_iobase, old_mapbase;
 901		unsigned int old_type, old_iotype, old_hub6, old_shift;
 902
 903		old_iobase = uport->iobase;
 904		old_mapbase = uport->mapbase;
 905		old_type = uport->type;
 906		old_hub6 = uport->hub6;
 907		old_iotype = uport->iotype;
 908		old_shift = uport->regshift;
 909
 910		/*
 911		 * Free and release old regions
 912		 */
 913		if (old_type != PORT_UNKNOWN && uport->ops->release_port)
 914			uport->ops->release_port(uport);
 915
 916		uport->iobase = new_port;
 917		uport->type = new_info->type;
 918		uport->hub6 = new_info->hub6;
 919		uport->iotype = new_info->io_type;
 920		uport->regshift = new_info->iomem_reg_shift;
 921		uport->mapbase = (unsigned long)new_info->iomem_base;
 922
 923		/*
 924		 * Claim and map the new regions
 925		 */
 926		if (uport->type != PORT_UNKNOWN && uport->ops->request_port) {
 927			retval = uport->ops->request_port(uport);
 928		} else {
 929			/* Always success - Jean II */
 930			retval = 0;
 931		}
 932
 933		/*
 934		 * If we fail to request resources for the
 935		 * new port, try to restore the old settings.
 936		 */
 937		if (retval) {
 938			uport->iobase = old_iobase;
 939			uport->type = old_type;
 940			uport->hub6 = old_hub6;
 941			uport->iotype = old_iotype;
 942			uport->regshift = old_shift;
 943			uport->mapbase = old_mapbase;
 944
 945			if (old_type != PORT_UNKNOWN) {
 946				retval = uport->ops->request_port(uport);
 947				/*
 948				 * If we failed to restore the old settings,
 949				 * we fail like this.
 950				 */
 951				if (retval)
 952					uport->type = PORT_UNKNOWN;
 953
 954				/*
 955				 * We failed anyway.
 956				 */
 957				retval = -EBUSY;
 958			}
 959
 960			/* Added to return the correct error -Ram Gupta */
 961			goto exit;
 962		}
 963	}
 964
 965	if (change_irq)
 966		uport->irq      = new_info->irq;
 967	if (!(uport->flags & UPF_FIXED_PORT))
 968		uport->uartclk  = new_info->baud_base * 16;
 969	uport->flags            = (uport->flags & ~UPF_CHANGE_MASK) |
 970				 (new_flags & UPF_CHANGE_MASK);
 971	uport->custom_divisor   = new_info->custom_divisor;
 972	port->close_delay     = close_delay;
 973	port->closing_wait    = closing_wait;
 974	if (new_info->xmit_fifo_size)
 975		uport->fifosize = new_info->xmit_fifo_size;
 976	port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
 977
 978 check_and_exit:
 979	retval = 0;
 980	if (uport->type == PORT_UNKNOWN)
 981		goto exit;
 982	if (tty_port_initialized(port)) {
 983		if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
 984		    old_custom_divisor != uport->custom_divisor) {
 985			/*
 986			 * If they're setting up a custom divisor or speed,
 987			 * instead of clearing it, then bitch about it.
 988			 */
 989			if (uport->flags & UPF_SPD_MASK) {
 990				dev_notice_ratelimited(uport->dev,
 991				       "%s sets custom speed on %s. This is deprecated.\n",
 992				      current->comm,
 993				      tty_name(port->tty));
 994			}
 995			uart_change_speed(tty, state, NULL);
 996		}
 997	} else {
 998		retval = uart_startup(tty, state, 1);
 999		if (retval == 0)
1000			tty_port_set_initialized(port, true);
1001		if (retval > 0)
1002			retval = 0;
1003	}
1004 exit:
1005	return retval;
1006}
1007
1008static int uart_set_info_user(struct tty_struct *tty, struct serial_struct *ss)
1009{
1010	struct uart_state *state = tty->driver_data;
1011	struct tty_port *port = &state->port;
1012	int retval;
1013
1014	down_write(&tty->termios_rwsem);
1015	/*
1016	 * This semaphore protects port->count.  It is also
1017	 * very useful to prevent opens.  Also, take the
1018	 * port configuration semaphore to make sure that a
1019	 * module insertion/removal doesn't change anything
1020	 * under us.
1021	 */
1022	mutex_lock(&port->mutex);
1023	retval = uart_set_info(tty, port, state, ss);
1024	mutex_unlock(&port->mutex);
1025	up_write(&tty->termios_rwsem);
1026	return retval;
1027}
1028
1029/**
1030 *	uart_get_lsr_info	-	get line status register info
1031 *	@tty: tty associated with the UART
1032 *	@state: UART being queried
1033 *	@value: returned modem value
1034 */
1035static int uart_get_lsr_info(struct tty_struct *tty,
1036			struct uart_state *state, unsigned int __user *value)
1037{
1038	struct uart_port *uport = uart_port_check(state);
1039	unsigned int result;
1040
1041	result = uport->ops->tx_empty(uport);
1042
1043	/*
1044	 * If we're about to load something into the transmit
1045	 * register, we'll pretend the transmitter isn't empty to
1046	 * avoid a race condition (depending on when the transmit
1047	 * interrupt happens).
1048	 */
1049	if (uport->x_char ||
1050	    ((uart_circ_chars_pending(&state->xmit) > 0) &&
1051	     !uart_tx_stopped(uport)))
1052		result &= ~TIOCSER_TEMT;
1053
1054	return put_user(result, value);
1055}
1056
1057static int uart_tiocmget(struct tty_struct *tty)
1058{
1059	struct uart_state *state = tty->driver_data;
1060	struct tty_port *port = &state->port;
1061	struct uart_port *uport;
1062	int result = -EIO;
1063
1064	mutex_lock(&port->mutex);
1065	uport = uart_port_check(state);
1066	if (!uport)
1067		goto out;
1068
1069	if (!tty_io_error(tty)) {
 
1070		result = uport->mctrl;
1071		spin_lock_irq(&uport->lock);
1072		result |= uport->ops->get_mctrl(uport);
1073		spin_unlock_irq(&uport->lock);
1074	}
1075out:
1076	mutex_unlock(&port->mutex);
1077	return result;
1078}
1079
1080static int
1081uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
1082{
1083	struct uart_state *state = tty->driver_data;
1084	struct tty_port *port = &state->port;
1085	struct uart_port *uport;
1086	int ret = -EIO;
1087
1088	mutex_lock(&port->mutex);
1089	uport = uart_port_check(state);
1090	if (!uport)
1091		goto out;
1092
1093	if (!tty_io_error(tty)) {
1094		uart_update_mctrl(uport, set, clear);
1095		ret = 0;
1096	}
1097out:
1098	mutex_unlock(&port->mutex);
1099	return ret;
1100}
1101
1102static int uart_break_ctl(struct tty_struct *tty, int break_state)
1103{
1104	struct uart_state *state = tty->driver_data;
1105	struct tty_port *port = &state->port;
1106	struct uart_port *uport;
1107	int ret = -EIO;
1108
1109	mutex_lock(&port->mutex);
1110	uport = uart_port_check(state);
1111	if (!uport)
1112		goto out;
1113
1114	if (uport->type != PORT_UNKNOWN)
1115		uport->ops->break_ctl(uport, break_state);
1116	ret = 0;
1117out:
1118	mutex_unlock(&port->mutex);
1119	return ret;
1120}
1121
1122static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state)
1123{
1124	struct tty_port *port = &state->port;
1125	struct uart_port *uport;
1126	int flags, ret;
1127
1128	if (!capable(CAP_SYS_ADMIN))
1129		return -EPERM;
1130
1131	/*
1132	 * Take the per-port semaphore.  This prevents count from
1133	 * changing, and hence any extra opens of the port while
1134	 * we're auto-configuring.
1135	 */
1136	if (mutex_lock_interruptible(&port->mutex))
1137		return -ERESTARTSYS;
1138
1139	uport = uart_port_check(state);
1140	if (!uport) {
1141		ret = -EIO;
1142		goto out;
1143	}
1144
1145	ret = -EBUSY;
1146	if (tty_port_users(port) == 1) {
1147		uart_shutdown(tty, state);
1148
1149		/*
1150		 * If we already have a port type configured,
1151		 * we must release its resources.
1152		 */
1153		if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
1154			uport->ops->release_port(uport);
1155
1156		flags = UART_CONFIG_TYPE;
1157		if (uport->flags & UPF_AUTO_IRQ)
1158			flags |= UART_CONFIG_IRQ;
1159
1160		/*
1161		 * This will claim the ports resources if
1162		 * a port is found.
1163		 */
1164		uport->ops->config_port(uport, flags);
1165
1166		ret = uart_startup(tty, state, 1);
1167		if (ret == 0)
1168			tty_port_set_initialized(port, true);
1169		if (ret > 0)
1170			ret = 0;
1171	}
1172out:
1173	mutex_unlock(&port->mutex);
1174	return ret;
1175}
1176
1177static void uart_enable_ms(struct uart_port *uport)
1178{
1179	/*
1180	 * Force modem status interrupts on
1181	 */
1182	if (uport->ops->enable_ms)
1183		uport->ops->enable_ms(uport);
1184}
1185
1186/*
1187 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1188 * - mask passed in arg for lines of interest
1189 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1190 * Caller should use TIOCGICOUNT to see which one it was
1191 *
1192 * FIXME: This wants extracting into a common all driver implementation
1193 * of TIOCMWAIT using tty_port.
1194 */
1195static int uart_wait_modem_status(struct uart_state *state, unsigned long arg)
1196{
1197	struct uart_port *uport;
1198	struct tty_port *port = &state->port;
1199	DECLARE_WAITQUEUE(wait, current);
1200	struct uart_icount cprev, cnow;
1201	int ret;
1202
1203	/*
1204	 * note the counters on entry
1205	 */
1206	uport = uart_port_ref(state);
1207	if (!uport)
1208		return -EIO;
1209	spin_lock_irq(&uport->lock);
1210	memcpy(&cprev, &uport->icount, sizeof(struct uart_icount));
1211	uart_enable_ms(uport);
1212	spin_unlock_irq(&uport->lock);
1213
1214	add_wait_queue(&port->delta_msr_wait, &wait);
1215	for (;;) {
1216		spin_lock_irq(&uport->lock);
1217		memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1218		spin_unlock_irq(&uport->lock);
1219
1220		set_current_state(TASK_INTERRUPTIBLE);
1221
1222		if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1223		    ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1224		    ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
1225		    ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
1226			ret = 0;
1227			break;
1228		}
1229
1230		schedule();
1231
1232		/* see if a signal did it */
1233		if (signal_pending(current)) {
1234			ret = -ERESTARTSYS;
1235			break;
1236		}
1237
1238		cprev = cnow;
1239	}
1240	__set_current_state(TASK_RUNNING);
1241	remove_wait_queue(&port->delta_msr_wait, &wait);
1242	uart_port_deref(uport);
1243
1244	return ret;
1245}
1246
1247/*
1248 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1249 * Return: write counters to the user passed counter struct
1250 * NB: both 1->0 and 0->1 transitions are counted except for
1251 *     RI where only 0->1 is counted.
1252 */
1253static int uart_get_icount(struct tty_struct *tty,
1254			  struct serial_icounter_struct *icount)
1255{
1256	struct uart_state *state = tty->driver_data;
1257	struct uart_icount cnow;
1258	struct uart_port *uport;
1259
1260	uport = uart_port_ref(state);
1261	if (!uport)
1262		return -EIO;
1263	spin_lock_irq(&uport->lock);
1264	memcpy(&cnow, &uport->icount, sizeof(struct uart_icount));
1265	spin_unlock_irq(&uport->lock);
1266	uart_port_deref(uport);
1267
1268	icount->cts         = cnow.cts;
1269	icount->dsr         = cnow.dsr;
1270	icount->rng         = cnow.rng;
1271	icount->dcd         = cnow.dcd;
1272	icount->rx          = cnow.rx;
1273	icount->tx          = cnow.tx;
1274	icount->frame       = cnow.frame;
1275	icount->overrun     = cnow.overrun;
1276	icount->parity      = cnow.parity;
1277	icount->brk         = cnow.brk;
1278	icount->buf_overrun = cnow.buf_overrun;
1279
1280	return 0;
1281}
1282
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1283static int uart_get_rs485_config(struct uart_port *port,
1284			 struct serial_rs485 __user *rs485)
1285{
1286	unsigned long flags;
1287	struct serial_rs485 aux;
1288
1289	spin_lock_irqsave(&port->lock, flags);
1290	aux = port->rs485;
1291	spin_unlock_irqrestore(&port->lock, flags);
1292
1293	if (copy_to_user(rs485, &aux, sizeof(aux)))
1294		return -EFAULT;
1295
1296	return 0;
1297}
1298
1299static int uart_set_rs485_config(struct uart_port *port,
1300			 struct serial_rs485 __user *rs485_user)
1301{
1302	struct serial_rs485 rs485;
1303	int ret;
1304	unsigned long flags;
1305
1306	if (!port->rs485_config)
1307		return -ENOIOCTLCMD;
1308
1309	if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user)))
1310		return -EFAULT;
1311
1312	spin_lock_irqsave(&port->lock, flags);
1313	ret = port->rs485_config(port, &rs485);
1314	spin_unlock_irqrestore(&port->lock, flags);
1315	if (ret)
1316		return ret;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1317
1318	if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485)))
1319		return -EFAULT;
1320
1321	return 0;
1322}
1323
1324static int uart_get_iso7816_config(struct uart_port *port,
1325				   struct serial_iso7816 __user *iso7816)
1326{
1327	unsigned long flags;
1328	struct serial_iso7816 aux;
1329
1330	if (!port->iso7816_config)
1331		return -ENOIOCTLCMD;
1332
1333	spin_lock_irqsave(&port->lock, flags);
1334	aux = port->iso7816;
1335	spin_unlock_irqrestore(&port->lock, flags);
1336
1337	if (copy_to_user(iso7816, &aux, sizeof(aux)))
1338		return -EFAULT;
1339
1340	return 0;
1341}
1342
1343static int uart_set_iso7816_config(struct uart_port *port,
1344				   struct serial_iso7816 __user *iso7816_user)
1345{
1346	struct serial_iso7816 iso7816;
1347	int i, ret;
1348	unsigned long flags;
1349
1350	if (!port->iso7816_config)
1351		return -ENOIOCTLCMD;
1352
1353	if (copy_from_user(&iso7816, iso7816_user, sizeof(*iso7816_user)))
1354		return -EFAULT;
1355
1356	/*
1357	 * There are 5 words reserved for future use. Check that userspace
1358	 * doesn't put stuff in there to prevent breakages in the future.
1359	 */
1360	for (i = 0; i < 5; i++)
1361		if (iso7816.reserved[i])
1362			return -EINVAL;
1363
1364	spin_lock_irqsave(&port->lock, flags);
1365	ret = port->iso7816_config(port, &iso7816);
1366	spin_unlock_irqrestore(&port->lock, flags);
1367	if (ret)
1368		return ret;
1369
1370	if (copy_to_user(iso7816_user, &port->iso7816, sizeof(port->iso7816)))
1371		return -EFAULT;
1372
1373	return 0;
1374}
1375
1376/*
1377 * Called via sys_ioctl.  We can use spin_lock_irq() here.
1378 */
1379static int
1380uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
1381{
1382	struct uart_state *state = tty->driver_data;
1383	struct tty_port *port = &state->port;
1384	struct uart_port *uport;
1385	void __user *uarg = (void __user *)arg;
1386	int ret = -ENOIOCTLCMD;
1387
1388
1389	/*
1390	 * These ioctls don't rely on the hardware to be present.
1391	 */
1392	switch (cmd) {
1393	case TIOCSERCONFIG:
1394		down_write(&tty->termios_rwsem);
1395		ret = uart_do_autoconfig(tty, state);
1396		up_write(&tty->termios_rwsem);
1397		break;
1398	}
1399
1400	if (ret != -ENOIOCTLCMD)
1401		goto out;
1402
1403	if (tty_io_error(tty)) {
1404		ret = -EIO;
1405		goto out;
1406	}
1407
1408	/*
1409	 * The following should only be used when hardware is present.
1410	 */
1411	switch (cmd) {
1412	case TIOCMIWAIT:
1413		ret = uart_wait_modem_status(state, arg);
1414		break;
1415	}
1416
1417	if (ret != -ENOIOCTLCMD)
1418		goto out;
1419
 
 
 
 
1420	mutex_lock(&port->mutex);
1421	uport = uart_port_check(state);
1422
1423	if (!uport || tty_io_error(tty)) {
1424		ret = -EIO;
1425		goto out_up;
1426	}
1427
1428	/*
1429	 * All these rely on hardware being present and need to be
1430	 * protected against the tty being hung up.
1431	 */
1432
1433	switch (cmd) {
1434	case TIOCSERGETLSR: /* Get line status register */
1435		ret = uart_get_lsr_info(tty, state, uarg);
1436		break;
1437
1438	case TIOCGRS485:
1439		ret = uart_get_rs485_config(uport, uarg);
1440		break;
1441
1442	case TIOCSRS485:
1443		ret = uart_set_rs485_config(uport, uarg);
1444		break;
1445
1446	case TIOCSISO7816:
1447		ret = uart_set_iso7816_config(state->uart_port, uarg);
1448		break;
1449
1450	case TIOCGISO7816:
1451		ret = uart_get_iso7816_config(state->uart_port, uarg);
1452		break;
1453	default:
1454		if (uport->ops->ioctl)
1455			ret = uport->ops->ioctl(uport, cmd, arg);
1456		break;
1457	}
1458out_up:
1459	mutex_unlock(&port->mutex);
 
 
1460out:
1461	return ret;
1462}
1463
1464static void uart_set_ldisc(struct tty_struct *tty)
1465{
1466	struct uart_state *state = tty->driver_data;
1467	struct uart_port *uport;
 
 
 
 
1468
1469	mutex_lock(&state->port.mutex);
1470	uport = uart_port_check(state);
1471	if (uport && uport->ops->set_ldisc)
1472		uport->ops->set_ldisc(uport, &tty->termios);
1473	mutex_unlock(&state->port.mutex);
1474}
1475
1476static void uart_set_termios(struct tty_struct *tty,
1477						struct ktermios *old_termios)
1478{
1479	struct uart_state *state = tty->driver_data;
1480	struct uart_port *uport;
1481	unsigned int cflag = tty->termios.c_cflag;
1482	unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK;
1483	bool sw_changed = false;
1484
1485	mutex_lock(&state->port.mutex);
1486	uport = uart_port_check(state);
1487	if (!uport)
1488		goto out;
1489
1490	/*
1491	 * Drivers doing software flow control also need to know
1492	 * about changes to these input settings.
1493	 */
1494	if (uport->flags & UPF_SOFT_FLOW) {
1495		iflag_mask |= IXANY|IXON|IXOFF;
1496		sw_changed =
1497		   tty->termios.c_cc[VSTART] != old_termios->c_cc[VSTART] ||
1498		   tty->termios.c_cc[VSTOP] != old_termios->c_cc[VSTOP];
1499	}
1500
1501	/*
1502	 * These are the bits that are used to setup various
1503	 * flags in the low level driver. We can ignore the Bfoo
1504	 * bits in c_cflag; c_[io]speed will always be set
1505	 * appropriately by set_termios() in tty_ioctl.c
1506	 */
1507	if ((cflag ^ old_termios->c_cflag) == 0 &&
1508	    tty->termios.c_ospeed == old_termios->c_ospeed &&
1509	    tty->termios.c_ispeed == old_termios->c_ispeed &&
1510	    ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 &&
1511	    !sw_changed) {
1512		goto out;
1513	}
1514
1515	uart_change_speed(tty, state, old_termios);
1516	/* reload cflag from termios; port driver may have overridden flags */
1517	cflag = tty->termios.c_cflag;
1518
1519	/* Handle transition to B0 status */
1520	if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
1521		uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
1522	/* Handle transition away from B0 status */
1523	else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1524		unsigned int mask = TIOCM_DTR;
 
1525		if (!(cflag & CRTSCTS) || !tty_throttled(tty))
1526			mask |= TIOCM_RTS;
1527		uart_set_mctrl(uport, mask);
1528	}
1529out:
1530	mutex_unlock(&state->port.mutex);
1531}
1532
1533/*
1534 * Calls to uart_close() are serialised via the tty_lock in
1535 *   drivers/tty/tty_io.c:tty_release()
1536 *   drivers/tty/tty_io.c:do_tty_hangup()
1537 */
1538static void uart_close(struct tty_struct *tty, struct file *filp)
1539{
1540	struct uart_state *state = tty->driver_data;
1541
1542	if (!state) {
1543		struct uart_driver *drv = tty->driver->driver_state;
1544		struct tty_port *port;
1545
1546		state = drv->state + tty->index;
1547		port = &state->port;
1548		spin_lock_irq(&port->lock);
1549		--port->count;
1550		spin_unlock_irq(&port->lock);
1551		return;
1552	}
1553
1554	pr_debug("uart_close(%d) called\n", tty->index);
1555
1556	tty_port_close(tty->port, tty, filp);
1557}
1558
1559static void uart_tty_port_shutdown(struct tty_port *port)
1560{
1561	struct uart_state *state = container_of(port, struct uart_state, port);
1562	struct uart_port *uport = uart_port_check(state);
 
1563
1564	/*
1565	 * At this point, we stop accepting input.  To do this, we
1566	 * disable the receive line status interrupts.
1567	 */
1568	if (WARN(!uport, "detached port still initialized!\n"))
1569		return;
1570
1571	spin_lock_irq(&uport->lock);
1572	uport->ops->stop_rx(uport);
1573	spin_unlock_irq(&uport->lock);
1574
1575	uart_port_shutdown(port);
1576
1577	/*
1578	 * It's possible for shutdown to be called after suspend if we get
1579	 * a DCD drop (hangup) at just the right time.  Clear suspended bit so
1580	 * we don't try to resume a port that has been shutdown.
1581	 */
1582	tty_port_set_suspended(port, 0);
1583
1584	uart_change_pm(state, UART_PM_STATE_OFF);
 
 
 
 
 
 
1585
 
 
 
1586}
1587
1588static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
1589{
1590	struct uart_state *state = tty->driver_data;
1591	struct uart_port *port;
1592	unsigned long char_time, expire;
1593
1594	port = uart_port_ref(state);
1595	if (!port)
1596		return;
1597
1598	if (port->type == PORT_UNKNOWN || port->fifosize == 0) {
1599		uart_port_deref(port);
1600		return;
1601	}
1602
1603	/*
1604	 * Set the check interval to be 1/5 of the estimated time to
1605	 * send a single character, and make it at least 1.  The check
1606	 * interval should also be less than the timeout.
1607	 *
1608	 * Note: we have to use pretty tight timings here to satisfy
1609	 * the NIST-PCTS.
1610	 */
1611	char_time = (port->timeout - HZ/50) / port->fifosize;
1612	char_time = char_time / 5;
1613	if (char_time == 0)
1614		char_time = 1;
1615	if (timeout && timeout < char_time)
1616		char_time = timeout;
1617
1618	/*
1619	 * If the transmitter hasn't cleared in twice the approximate
1620	 * amount of time to send the entire FIFO, it probably won't
1621	 * ever clear.  This assumes the UART isn't doing flow
1622	 * control, which is currently the case.  Hence, if it ever
1623	 * takes longer than port->timeout, this is probably due to a
1624	 * UART bug of some kind.  So, we clamp the timeout parameter at
1625	 * 2*port->timeout.
1626	 */
1627	if (timeout == 0 || timeout > 2 * port->timeout)
1628		timeout = 2 * port->timeout;
 
 
 
1629
1630	expire = jiffies + timeout;
1631
1632	pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n",
1633		port->line, jiffies, expire);
1634
1635	/*
1636	 * Check whether the transmitter is empty every 'char_time'.
1637	 * 'timeout' / 'expire' give us the maximum amount of time
1638	 * we wait.
1639	 */
1640	while (!port->ops->tx_empty(port)) {
1641		msleep_interruptible(jiffies_to_msecs(char_time));
1642		if (signal_pending(current))
1643			break;
1644		if (time_after(jiffies, expire))
1645			break;
1646	}
1647	uart_port_deref(port);
1648}
1649
1650/*
1651 * Calls to uart_hangup() are serialised by the tty_lock in
1652 *   drivers/tty/tty_io.c:do_tty_hangup()
1653 * This runs from a workqueue and can sleep for a _short_ time only.
1654 */
1655static void uart_hangup(struct tty_struct *tty)
1656{
1657	struct uart_state *state = tty->driver_data;
1658	struct tty_port *port = &state->port;
1659	struct uart_port *uport;
1660	unsigned long flags;
1661
1662	pr_debug("uart_hangup(%d)\n", tty->index);
1663
1664	mutex_lock(&port->mutex);
1665	uport = uart_port_check(state);
1666	WARN(!uport, "hangup of detached port!\n");
1667
1668	if (tty_port_active(port)) {
1669		uart_flush_buffer(tty);
1670		uart_shutdown(tty, state);
1671		spin_lock_irqsave(&port->lock, flags);
1672		port->count = 0;
1673		spin_unlock_irqrestore(&port->lock, flags);
1674		tty_port_set_active(port, 0);
1675		tty_port_tty_set(port, NULL);
1676		if (uport && !uart_console(uport))
1677			uart_change_pm(state, UART_PM_STATE_OFF);
1678		wake_up_interruptible(&port->open_wait);
1679		wake_up_interruptible(&port->delta_msr_wait);
1680	}
1681	mutex_unlock(&port->mutex);
1682}
1683
1684/* uport == NULL if uart_port has already been removed */
1685static void uart_port_shutdown(struct tty_port *port)
1686{
1687	struct uart_state *state = container_of(port, struct uart_state, port);
1688	struct uart_port *uport = uart_port_check(state);
1689
1690	/*
1691	 * clear delta_msr_wait queue to avoid mem leaks: we may free
1692	 * the irq here so the queue might never be woken up.  Note
1693	 * that we won't end up waiting on delta_msr_wait again since
1694	 * any outstanding file descriptors should be pointing at
1695	 * hung_up_tty_fops now.
1696	 */
1697	wake_up_interruptible(&port->delta_msr_wait);
1698
1699	/*
1700	 * Free the IRQ and disable the port.
1701	 */
1702	if (uport)
1703		uport->ops->shutdown(uport);
1704
1705	/*
1706	 * Ensure that the IRQ handler isn't running on another CPU.
1707	 */
1708	if (uport)
1709		synchronize_irq(uport->irq);
 
1710}
1711
1712static int uart_carrier_raised(struct tty_port *port)
1713{
1714	struct uart_state *state = container_of(port, struct uart_state, port);
1715	struct uart_port *uport;
1716	int mctrl;
1717
1718	uport = uart_port_ref(state);
1719	/*
1720	 * Should never observe uport == NULL since checks for hangup should
1721	 * abort the tty_port_block_til_ready() loop before checking for carrier
1722	 * raised -- but report carrier raised if it does anyway so open will
1723	 * continue and not sleep
1724	 */
1725	if (WARN_ON(!uport))
1726		return 1;
1727	spin_lock_irq(&uport->lock);
1728	uart_enable_ms(uport);
1729	mctrl = uport->ops->get_mctrl(uport);
1730	spin_unlock_irq(&uport->lock);
1731	uart_port_deref(uport);
1732	if (mctrl & TIOCM_CAR)
1733		return 1;
1734	return 0;
1735}
1736
1737static void uart_dtr_rts(struct tty_port *port, int raise)
1738{
1739	struct uart_state *state = container_of(port, struct uart_state, port);
1740	struct uart_port *uport;
1741
1742	uport = uart_port_ref(state);
1743	if (!uport)
1744		return;
1745	uart_port_dtr_rts(uport, raise);
1746	uart_port_deref(uport);
1747}
1748
1749static int uart_install(struct tty_driver *driver, struct tty_struct *tty)
1750{
1751	struct uart_driver *drv = driver->driver_state;
1752	struct uart_state *state = drv->state + tty->index;
1753
1754	tty->driver_data = state;
1755
1756	return tty_standard_install(driver, tty);
1757}
1758
1759/*
1760 * Calls to uart_open are serialised by the tty_lock in
1761 *   drivers/tty/tty_io.c:tty_open()
1762 * Note that if this fails, then uart_close() _will_ be called.
1763 *
1764 * In time, we want to scrap the "opening nonpresent ports"
1765 * behaviour and implement an alternative way for setserial
1766 * to set base addresses/ports/types.  This will allow us to
1767 * get rid of a certain amount of extra tests.
1768 */
1769static int uart_open(struct tty_struct *tty, struct file *filp)
1770{
1771	struct uart_state *state = tty->driver_data;
1772	int retval;
1773
1774	retval = tty_port_open(&state->port, tty, filp);
1775	if (retval > 0)
1776		retval = 0;
1777
1778	return retval;
1779}
1780
1781static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
1782{
1783	struct uart_state *state = container_of(port, struct uart_state, port);
1784	struct uart_port *uport;
1785	int ret;
1786
1787	uport = uart_port_check(state);
1788	if (!uport || uport->flags & UPF_DEAD)
1789		return -ENXIO;
1790
1791	port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
1792
1793	/*
1794	 * Start up the serial port.
1795	 */
1796	ret = uart_startup(tty, state, 0);
1797	if (ret > 0)
1798		tty_port_set_active(port, 1);
1799
1800	return ret;
1801}
1802
1803static const char *uart_type(struct uart_port *port)
1804{
1805	const char *str = NULL;
1806
1807	if (port->ops->type)
1808		str = port->ops->type(port);
1809
1810	if (!str)
1811		str = "unknown";
1812
1813	return str;
1814}
1815
1816#ifdef CONFIG_PROC_FS
1817
1818static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
1819{
1820	struct uart_state *state = drv->state + i;
1821	struct tty_port *port = &state->port;
1822	enum uart_pm_state pm_state;
1823	struct uart_port *uport;
1824	char stat_buf[32];
1825	unsigned int status;
1826	int mmio;
1827
1828	mutex_lock(&port->mutex);
1829	uport = uart_port_check(state);
1830	if (!uport)
1831		goto out;
1832
1833	mmio = uport->iotype >= UPIO_MEM;
1834	seq_printf(m, "%d: uart:%s %s%08llX irq:%d",
1835			uport->line, uart_type(uport),
1836			mmio ? "mmio:0x" : "port:",
1837			mmio ? (unsigned long long)uport->mapbase
1838			     : (unsigned long long)uport->iobase,
1839			uport->irq);
1840
1841	if (uport->type == PORT_UNKNOWN) {
1842		seq_putc(m, '\n');
1843		goto out;
1844	}
1845
1846	if (capable(CAP_SYS_ADMIN)) {
1847		pm_state = state->pm_state;
1848		if (pm_state != UART_PM_STATE_ON)
1849			uart_change_pm(state, UART_PM_STATE_ON);
1850		spin_lock_irq(&uport->lock);
1851		status = uport->ops->get_mctrl(uport);
1852		spin_unlock_irq(&uport->lock);
1853		if (pm_state != UART_PM_STATE_ON)
1854			uart_change_pm(state, pm_state);
1855
1856		seq_printf(m, " tx:%d rx:%d",
1857				uport->icount.tx, uport->icount.rx);
1858		if (uport->icount.frame)
1859			seq_printf(m, " fe:%d",	uport->icount.frame);
1860		if (uport->icount.parity)
1861			seq_printf(m, " pe:%d",	uport->icount.parity);
1862		if (uport->icount.brk)
1863			seq_printf(m, " brk:%d", uport->icount.brk);
1864		if (uport->icount.overrun)
1865			seq_printf(m, " oe:%d", uport->icount.overrun);
1866		if (uport->icount.buf_overrun)
1867			seq_printf(m, " bo:%d", uport->icount.buf_overrun);
1868
1869#define INFOBIT(bit, str) \
1870	if (uport->mctrl & (bit)) \
1871		strncat(stat_buf, (str), sizeof(stat_buf) - \
1872			strlen(stat_buf) - 2)
1873#define STATBIT(bit, str) \
1874	if (status & (bit)) \
1875		strncat(stat_buf, (str), sizeof(stat_buf) - \
1876		       strlen(stat_buf) - 2)
1877
1878		stat_buf[0] = '\0';
1879		stat_buf[1] = '\0';
1880		INFOBIT(TIOCM_RTS, "|RTS");
1881		STATBIT(TIOCM_CTS, "|CTS");
1882		INFOBIT(TIOCM_DTR, "|DTR");
1883		STATBIT(TIOCM_DSR, "|DSR");
1884		STATBIT(TIOCM_CAR, "|CD");
1885		STATBIT(TIOCM_RNG, "|RI");
1886		if (stat_buf[0])
1887			stat_buf[0] = ' ';
1888
1889		seq_puts(m, stat_buf);
1890	}
1891	seq_putc(m, '\n');
1892#undef STATBIT
1893#undef INFOBIT
1894out:
1895	mutex_unlock(&port->mutex);
1896}
1897
1898static int uart_proc_show(struct seq_file *m, void *v)
1899{
1900	struct tty_driver *ttydrv = m->private;
1901	struct uart_driver *drv = ttydrv->driver_state;
1902	int i;
1903
1904	seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", "");
1905	for (i = 0; i < drv->nr; i++)
1906		uart_line_info(m, drv, i);
1907	return 0;
1908}
1909#endif
1910
 
 
 
 
 
 
1911#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
1912/**
1913 *	uart_console_write - write a console message to a serial port
1914 *	@port: the port to write the message
1915 *	@s: array of characters
1916 *	@count: number of characters in string to write
1917 *	@putchar: function to write character to port
1918 */
1919void uart_console_write(struct uart_port *port, const char *s,
1920			unsigned int count,
1921			void (*putchar)(struct uart_port *, int))
1922{
1923	unsigned int i;
1924
1925	for (i = 0; i < count; i++, s++) {
1926		if (*s == '\n')
1927			putchar(port, '\r');
1928		putchar(port, *s);
1929	}
1930}
1931EXPORT_SYMBOL_GPL(uart_console_write);
1932
1933/*
1934 *	Check whether an invalid uart number has been specified, and
1935 *	if so, search for the first available port that does have
1936 *	console support.
 
 
 
 
 
1937 */
1938struct uart_port * __init
1939uart_get_console(struct uart_port *ports, int nr, struct console *co)
1940{
1941	int idx = co->index;
1942
1943	if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 &&
1944				     ports[idx].membase == NULL))
1945		for (idx = 0; idx < nr; idx++)
1946			if (ports[idx].iobase != 0 ||
1947			    ports[idx].membase != NULL)
1948				break;
1949
1950	co->index = idx;
1951
1952	return ports + idx;
1953}
1954
1955/**
1956 *	uart_parse_earlycon - Parse earlycon options
1957 *	@p:	  ptr to 2nd field (ie., just beyond '<name>,')
1958 *	@iotype:  ptr for decoded iotype (out)
1959 *	@addr:    ptr for decoded mapbase/iobase (out)
1960 *	@options: ptr for <options> field; NULL if not present (out)
 
 
 
 
 
 
 
 
1961 *
1962 *	Decodes earlycon kernel command line parameters of the form
1963 *	   earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1964 *	   console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
1965 *
1966 *	The optional form
1967 *
1968 *	   earlycon=<name>,0x<addr>,<options>
1969 *	   console=<name>,0x<addr>,<options>
1970 *
1971 *	is also accepted; the returned @iotype will be UPIO_MEM.
1972 *
1973 *	Returns 0 on success or -EINVAL on failure
1974 */
1975int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr,
1976			char **options)
1977{
1978	if (strncmp(p, "mmio,", 5) == 0) {
1979		*iotype = UPIO_MEM;
1980		p += 5;
1981	} else if (strncmp(p, "mmio16,", 7) == 0) {
1982		*iotype = UPIO_MEM16;
1983		p += 7;
1984	} else if (strncmp(p, "mmio32,", 7) == 0) {
1985		*iotype = UPIO_MEM32;
1986		p += 7;
1987	} else if (strncmp(p, "mmio32be,", 9) == 0) {
1988		*iotype = UPIO_MEM32BE;
1989		p += 9;
1990	} else if (strncmp(p, "mmio32native,", 13) == 0) {
1991		*iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ?
1992			UPIO_MEM32BE : UPIO_MEM32;
1993		p += 13;
1994	} else if (strncmp(p, "io,", 3) == 0) {
1995		*iotype = UPIO_PORT;
1996		p += 3;
1997	} else if (strncmp(p, "0x", 2) == 0) {
1998		*iotype = UPIO_MEM;
1999	} else {
2000		return -EINVAL;
2001	}
2002
2003	/*
2004	 * Before you replace it with kstrtoull(), think about options separator
2005	 * (',') it will not tolerate
2006	 */
2007	*addr = simple_strtoull(p, NULL, 0);
2008	p = strchr(p, ',');
2009	if (p)
2010		p++;
2011
2012	*options = p;
2013	return 0;
2014}
2015EXPORT_SYMBOL_GPL(uart_parse_earlycon);
2016
2017/**
2018 *	uart_parse_options - Parse serial port baud/parity/bits/flow control.
2019 *	@options: pointer to option string
2020 *	@baud: pointer to an 'int' variable for the baud rate.
2021 *	@parity: pointer to an 'int' variable for the parity.
2022 *	@bits: pointer to an 'int' variable for the number of data bits.
2023 *	@flow: pointer to an 'int' variable for the flow control character.
2024 *
2025 *	uart_parse_options decodes a string containing the serial console
2026 *	options.  The format of the string is <baud><parity><bits><flow>,
2027 *	eg: 115200n8r
2028 */
2029void
2030uart_parse_options(const char *options, int *baud, int *parity,
2031		   int *bits, int *flow)
2032{
2033	const char *s = options;
2034
2035	*baud = simple_strtoul(s, NULL, 10);
2036	while (*s >= '0' && *s <= '9')
2037		s++;
2038	if (*s)
2039		*parity = *s++;
2040	if (*s)
2041		*bits = *s++ - '0';
2042	if (*s)
2043		*flow = *s;
2044}
2045EXPORT_SYMBOL_GPL(uart_parse_options);
2046
2047/**
2048 *	uart_set_options - setup the serial console parameters
2049 *	@port: pointer to the serial ports uart_port structure
2050 *	@co: console pointer
2051 *	@baud: baud rate
2052 *	@parity: parity character - 'n' (none), 'o' (odd), 'e' (even)
2053 *	@bits: number of data bits
2054 *	@flow: flow control character - 'r' (rts)
 
 
 
2055 */
2056int
2057uart_set_options(struct uart_port *port, struct console *co,
2058		 int baud, int parity, int bits, int flow)
2059{
2060	struct ktermios termios;
2061	static struct ktermios dummy;
2062
2063	/*
2064	 * Ensure that the serial console lock is initialised
2065	 * early.
2066	 * If this port is a console, then the spinlock is already
2067	 * initialised.
 
2068	 */
2069	if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
2070		spin_lock_init(&port->lock);
2071		lockdep_set_class(&port->lock, &port_lock_key);
2072	}
2073
2074	memset(&termios, 0, sizeof(struct ktermios));
2075
2076	termios.c_cflag |= CREAD | HUPCL | CLOCAL;
2077	tty_termios_encode_baud_rate(&termios, baud, baud);
2078
2079	if (bits == 7)
2080		termios.c_cflag |= CS7;
2081	else
2082		termios.c_cflag |= CS8;
2083
2084	switch (parity) {
2085	case 'o': case 'O':
2086		termios.c_cflag |= PARODD;
2087		/*fall through*/
2088	case 'e': case 'E':
2089		termios.c_cflag |= PARENB;
2090		break;
2091	}
2092
2093	if (flow == 'r')
2094		termios.c_cflag |= CRTSCTS;
2095
2096	/*
2097	 * some uarts on other side don't support no flow control.
2098	 * So we set * DTR in host uart to make them happy
2099	 */
2100	port->mctrl |= TIOCM_DTR;
2101
2102	port->ops->set_termios(port, &termios, &dummy);
2103	/*
2104	 * Allow the setting of the UART parameters with a NULL console
2105	 * too:
2106	 */
2107	if (co)
2108		co->cflag = termios.c_cflag;
 
 
 
2109
2110	return 0;
2111}
2112EXPORT_SYMBOL_GPL(uart_set_options);
2113#endif /* CONFIG_SERIAL_CORE_CONSOLE */
2114
2115/**
2116 * uart_change_pm - set power state of the port
2117 *
2118 * @state: port descriptor
2119 * @pm_state: new state
2120 *
2121 * Locking: port->mutex has to be held
2122 */
2123static void uart_change_pm(struct uart_state *state,
2124			   enum uart_pm_state pm_state)
2125{
2126	struct uart_port *port = uart_port_check(state);
2127
2128	if (state->pm_state != pm_state) {
2129		if (port && port->ops->pm)
2130			port->ops->pm(port, pm_state, state->pm_state);
2131		state->pm_state = pm_state;
2132	}
2133}
2134
2135struct uart_match {
2136	struct uart_port *port;
2137	struct uart_driver *driver;
2138};
2139
2140static int serial_match_port(struct device *dev, void *data)
2141{
2142	struct uart_match *match = data;
2143	struct tty_driver *tty_drv = match->driver->tty_driver;
2144	dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
2145		match->port->line;
2146
2147	return dev->devt == devt; /* Actually, only one tty per port */
2148}
2149
2150int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
2151{
2152	struct uart_state *state = drv->state + uport->line;
2153	struct tty_port *port = &state->port;
2154	struct device *tty_dev;
2155	struct uart_match match = {uport, drv};
2156
2157	mutex_lock(&port->mutex);
2158
2159	tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2160	if (tty_dev && device_may_wakeup(tty_dev)) {
2161		enable_irq_wake(uport->irq);
2162		put_device(tty_dev);
2163		mutex_unlock(&port->mutex);
2164		return 0;
2165	}
2166	put_device(tty_dev);
2167
2168	/* Nothing to do if the console is not suspending */
2169	if (!console_suspend_enabled && uart_console(uport))
 
 
 
 
 
 
 
 
 
 
2170		goto unlock;
 
2171
2172	uport->suspended = 1;
2173
2174	if (tty_port_initialized(port)) {
2175		const struct uart_ops *ops = uport->ops;
2176		int tries;
 
2177
2178		tty_port_set_suspended(port, 1);
2179		tty_port_set_initialized(port, 0);
2180
2181		spin_lock_irq(&uport->lock);
2182		ops->stop_tx(uport);
2183		ops->set_mctrl(uport, 0);
 
 
 
 
2184		ops->stop_rx(uport);
2185		spin_unlock_irq(&uport->lock);
2186
2187		/*
2188		 * Wait for the transmitter to empty.
2189		 */
2190		for (tries = 3; !ops->tx_empty(uport) && tries; tries--)
2191			msleep(10);
2192		if (!tries)
2193			dev_err(uport->dev, "%s: Unable to drain transmitter\n",
2194				uport->name);
2195
2196		ops->shutdown(uport);
 
2197	}
2198
2199	/*
2200	 * Disable the console device before suspending.
2201	 */
2202	if (uart_console(uport))
2203		console_stop(uport->cons);
2204
2205	uart_change_pm(state, UART_PM_STATE_OFF);
2206unlock:
2207	mutex_unlock(&port->mutex);
2208
2209	return 0;
2210}
 
2211
2212int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
2213{
2214	struct uart_state *state = drv->state + uport->line;
2215	struct tty_port *port = &state->port;
2216	struct device *tty_dev;
2217	struct uart_match match = {uport, drv};
2218	struct ktermios termios;
2219
2220	mutex_lock(&port->mutex);
2221
2222	tty_dev = device_find_child(uport->dev, &match, serial_match_port);
2223	if (!uport->suspended && device_may_wakeup(tty_dev)) {
2224		if (irqd_is_wakeup_set(irq_get_irq_data((uport->irq))))
2225			disable_irq_wake(uport->irq);
2226		put_device(tty_dev);
2227		mutex_unlock(&port->mutex);
2228		return 0;
2229	}
2230	put_device(tty_dev);
2231	uport->suspended = 0;
2232
2233	/*
2234	 * Re-enable the console device after suspending.
2235	 */
2236	if (uart_console(uport)) {
2237		/*
2238		 * First try to use the console cflag setting.
2239		 */
2240		memset(&termios, 0, sizeof(struct ktermios));
2241		termios.c_cflag = uport->cons->cflag;
 
 
2242
2243		/*
2244		 * If that's unset, use the tty termios setting.
2245		 */
2246		if (port->tty && termios.c_cflag == 0)
2247			termios = port->tty->termios;
2248
2249		if (console_suspend_enabled)
2250			uart_change_pm(state, UART_PM_STATE_ON);
2251		uport->ops->set_termios(uport, &termios, NULL);
 
 
 
 
 
2252		if (console_suspend_enabled)
2253			console_start(uport->cons);
2254	}
2255
2256	if (tty_port_suspended(port)) {
2257		const struct uart_ops *ops = uport->ops;
2258		int ret;
2259
2260		uart_change_pm(state, UART_PM_STATE_ON);
2261		spin_lock_irq(&uport->lock);
2262		ops->set_mctrl(uport, 0);
2263		spin_unlock_irq(&uport->lock);
 
2264		if (console_suspend_enabled || !uart_console(uport)) {
2265			/* Protected by port mutex for now */
2266			struct tty_struct *tty = port->tty;
 
2267			ret = ops->startup(uport);
2268			if (ret == 0) {
2269				if (tty)
2270					uart_change_speed(tty, state, NULL);
2271				spin_lock_irq(&uport->lock);
2272				ops->set_mctrl(uport, uport->mctrl);
 
 
2273				ops->start_tx(uport);
2274				spin_unlock_irq(&uport->lock);
2275				tty_port_set_initialized(port, 1);
2276			} else {
2277				/*
2278				 * Failed to resume - maybe hardware went away?
2279				 * Clear the "initialized" flag so we won't try
2280				 * to call the low level drivers shutdown method.
2281				 */
2282				uart_shutdown(tty, state);
2283			}
2284		}
2285
2286		tty_port_set_suspended(port, 0);
2287	}
2288
2289	mutex_unlock(&port->mutex);
2290
2291	return 0;
2292}
 
2293
2294static inline void
2295uart_report_port(struct uart_driver *drv, struct uart_port *port)
2296{
2297	char address[64];
2298
2299	switch (port->iotype) {
2300	case UPIO_PORT:
2301		snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
2302		break;
2303	case UPIO_HUB6:
2304		snprintf(address, sizeof(address),
2305			 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
2306		break;
2307	case UPIO_MEM:
2308	case UPIO_MEM16:
2309	case UPIO_MEM32:
2310	case UPIO_MEM32BE:
2311	case UPIO_AU:
2312	case UPIO_TSI:
2313		snprintf(address, sizeof(address),
2314			 "MMIO 0x%llx", (unsigned long long)port->mapbase);
2315		break;
2316	default:
2317		strlcpy(address, "*unknown*", sizeof(address));
2318		break;
2319	}
2320
2321	pr_info("%s%s%s at %s (irq = %d, base_baud = %d) is a %s\n",
2322	       port->dev ? dev_name(port->dev) : "",
2323	       port->dev ? ": " : "",
2324	       port->name,
2325	       address, port->irq, port->uartclk / 16, uart_type(port));
 
 
 
 
 
 
 
 
2326}
2327
2328static void
2329uart_configure_port(struct uart_driver *drv, struct uart_state *state,
2330		    struct uart_port *port)
2331{
2332	unsigned int flags;
2333
2334	/*
2335	 * If there isn't a port here, don't do anything further.
2336	 */
2337	if (!port->iobase && !port->mapbase && !port->membase)
2338		return;
2339
2340	/*
2341	 * Now do the auto configuration stuff.  Note that config_port
2342	 * is expected to claim the resources and map the port for us.
2343	 */
2344	flags = 0;
2345	if (port->flags & UPF_AUTO_IRQ)
2346		flags |= UART_CONFIG_IRQ;
2347	if (port->flags & UPF_BOOT_AUTOCONF) {
2348		if (!(port->flags & UPF_FIXED_TYPE)) {
2349			port->type = PORT_UNKNOWN;
2350			flags |= UART_CONFIG_TYPE;
2351		}
2352		port->ops->config_port(port, flags);
2353	}
2354
2355	if (port->type != PORT_UNKNOWN) {
2356		unsigned long flags;
2357
2358		uart_report_port(drv, port);
2359
2360		/* Power up port for set_mctrl() */
2361		uart_change_pm(state, UART_PM_STATE_ON);
2362
2363		/*
2364		 * Ensure that the modem control lines are de-activated.
2365		 * keep the DTR setting that is set in uart_set_options()
2366		 * We probably don't need a spinlock around this, but
2367		 */
2368		spin_lock_irqsave(&port->lock, flags);
2369		port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR);
2370		spin_unlock_irqrestore(&port->lock, flags);
 
 
 
 
2371
2372		/*
2373		 * If this driver supports console, and it hasn't been
2374		 * successfully registered yet, try to re-register it.
2375		 * It may be that the port was not available.
2376		 */
2377		if (port->cons && !(port->cons->flags & CON_ENABLED))
2378			register_console(port->cons);
2379
2380		/*
2381		 * Power down all ports by default, except the
2382		 * console if we have one.
2383		 */
2384		if (!uart_console(port))
2385			uart_change_pm(state, UART_PM_STATE_OFF);
2386	}
2387}
2388
2389#ifdef CONFIG_CONSOLE_POLL
2390
2391static int uart_poll_init(struct tty_driver *driver, int line, char *options)
2392{
2393	struct uart_driver *drv = driver->driver_state;
2394	struct uart_state *state = drv->state + line;
 
2395	struct tty_port *tport;
2396	struct uart_port *port;
2397	int baud = 9600;
2398	int bits = 8;
2399	int parity = 'n';
2400	int flow = 'n';
2401	int ret = 0;
2402
2403	tport = &state->port;
2404	mutex_lock(&tport->mutex);
2405
2406	port = uart_port_check(state);
2407	if (!port || !(port->ops->poll_get_char && port->ops->poll_put_char)) {
 
2408		ret = -1;
2409		goto out;
2410	}
2411
 
 
 
2412	if (port->ops->poll_init) {
2413		/*
2414		 * We don't set initialized as we only initialized the hw,
2415		 * e.g. state->xmit is still uninitialized.
2416		 */
2417		if (!tty_port_initialized(tport))
2418			ret = port->ops->poll_init(port);
2419	}
2420
2421	if (!ret && options) {
2422		uart_parse_options(options, &baud, &parity, &bits, &flow);
 
2423		ret = uart_set_options(port, NULL, baud, parity, bits, flow);
 
2424	}
2425out:
 
 
2426	mutex_unlock(&tport->mutex);
2427	return ret;
2428}
2429
2430static int uart_poll_get_char(struct tty_driver *driver, int line)
2431{
2432	struct uart_driver *drv = driver->driver_state;
2433	struct uart_state *state = drv->state + line;
2434	struct uart_port *port;
2435	int ret = -1;
2436
2437	port = uart_port_ref(state);
2438	if (port) {
2439		ret = port->ops->poll_get_char(port);
2440		uart_port_deref(port);
2441	}
2442
2443	return ret;
2444}
2445
2446static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
2447{
2448	struct uart_driver *drv = driver->driver_state;
2449	struct uart_state *state = drv->state + line;
2450	struct uart_port *port;
2451
2452	port = uart_port_ref(state);
2453	if (!port)
2454		return;
2455
2456	if (ch == '\n')
2457		port->ops->poll_put_char(port, '\r');
2458	port->ops->poll_put_char(port, ch);
2459	uart_port_deref(port);
2460}
2461#endif
2462
2463static const struct tty_operations uart_ops = {
2464	.install	= uart_install,
2465	.open		= uart_open,
2466	.close		= uart_close,
2467	.write		= uart_write,
2468	.put_char	= uart_put_char,
2469	.flush_chars	= uart_flush_chars,
2470	.write_room	= uart_write_room,
2471	.chars_in_buffer= uart_chars_in_buffer,
2472	.flush_buffer	= uart_flush_buffer,
2473	.ioctl		= uart_ioctl,
2474	.throttle	= uart_throttle,
2475	.unthrottle	= uart_unthrottle,
2476	.send_xchar	= uart_send_xchar,
2477	.set_termios	= uart_set_termios,
2478	.set_ldisc	= uart_set_ldisc,
2479	.stop		= uart_stop,
2480	.start		= uart_start,
2481	.hangup		= uart_hangup,
2482	.break_ctl	= uart_break_ctl,
2483	.wait_until_sent= uart_wait_until_sent,
2484#ifdef CONFIG_PROC_FS
2485	.proc_show	= uart_proc_show,
2486#endif
2487	.tiocmget	= uart_tiocmget,
2488	.tiocmset	= uart_tiocmset,
2489	.set_serial	= uart_set_info_user,
2490	.get_serial	= uart_get_info_user,
2491	.get_icount	= uart_get_icount,
2492#ifdef CONFIG_CONSOLE_POLL
2493	.poll_init	= uart_poll_init,
2494	.poll_get_char	= uart_poll_get_char,
2495	.poll_put_char	= uart_poll_put_char,
2496#endif
2497};
2498
2499static const struct tty_port_operations uart_port_ops = {
2500	.carrier_raised = uart_carrier_raised,
2501	.dtr_rts	= uart_dtr_rts,
2502	.activate	= uart_port_activate,
2503	.shutdown	= uart_tty_port_shutdown,
2504};
2505
2506/**
2507 *	uart_register_driver - register a driver with the uart core layer
2508 *	@drv: low level driver structure
 
 
 
2509 *
2510 *	Register a uart driver with the core driver.  We in turn register
2511 *	with the tty layer, and initialise the core driver per-port state.
2512 *
2513 *	We have a proc file in /proc/tty/driver which is named after the
2514 *	normal driver.
2515 *
2516 *	drv->port should be NULL, and the per-port structures should be
2517 *	registered using uart_add_one_port after this call has succeeded.
2518 */
2519int uart_register_driver(struct uart_driver *drv)
2520{
2521	struct tty_driver *normal;
2522	int i, retval = -ENOMEM;
2523
2524	BUG_ON(drv->state);
2525
2526	/*
2527	 * Maybe we should be using a slab cache for this, especially if
2528	 * we have a large number of ports to handle.
2529	 */
2530	drv->state = kcalloc(drv->nr, sizeof(struct uart_state), GFP_KERNEL);
2531	if (!drv->state)
2532		goto out;
2533
2534	normal = alloc_tty_driver(drv->nr);
2535	if (!normal)
 
 
2536		goto out_kfree;
 
2537
2538	drv->tty_driver = normal;
2539
2540	normal->driver_name	= drv->driver_name;
2541	normal->name		= drv->dev_name;
2542	normal->major		= drv->major;
2543	normal->minor_start	= drv->minor;
2544	normal->type		= TTY_DRIVER_TYPE_SERIAL;
2545	normal->subtype		= SERIAL_TYPE_NORMAL;
2546	normal->init_termios	= tty_std_termios;
2547	normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
2548	normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600;
2549	normal->flags		= TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
2550	normal->driver_state    = drv;
2551	tty_set_operations(normal, &uart_ops);
2552
2553	/*
2554	 * Initialise the UART state(s).
2555	 */
2556	for (i = 0; i < drv->nr; i++) {
2557		struct uart_state *state = drv->state + i;
2558		struct tty_port *port = &state->port;
2559
2560		tty_port_init(port);
2561		port->ops = &uart_port_ops;
2562	}
2563
2564	retval = tty_register_driver(normal);
2565	if (retval >= 0)
2566		return retval;
2567
2568	for (i = 0; i < drv->nr; i++)
2569		tty_port_destroy(&drv->state[i].port);
2570	put_tty_driver(normal);
2571out_kfree:
2572	kfree(drv->state);
2573out:
2574	return retval;
2575}
 
2576
2577/**
2578 *	uart_unregister_driver - remove a driver from the uart core layer
2579 *	@drv: low level driver structure
 
 
 
 
2580 *
2581 *	Remove all references to a driver from the core driver.  The low
2582 *	level driver must have removed all its ports via the
2583 *	uart_remove_one_port() if it registered them with uart_add_one_port().
2584 *	(ie, drv->port == NULL)
2585 */
2586void uart_unregister_driver(struct uart_driver *drv)
2587{
2588	struct tty_driver *p = drv->tty_driver;
2589	unsigned int i;
2590
2591	tty_unregister_driver(p);
2592	put_tty_driver(p);
2593	for (i = 0; i < drv->nr; i++)
2594		tty_port_destroy(&drv->state[i].port);
2595	kfree(drv->state);
2596	drv->state = NULL;
2597	drv->tty_driver = NULL;
2598}
 
2599
2600struct tty_driver *uart_console_device(struct console *co, int *index)
2601{
2602	struct uart_driver *p = co->data;
2603	*index = co->index;
2604	return p->tty_driver;
2605}
 
2606
2607static ssize_t uart_get_attr_uartclk(struct device *dev,
2608	struct device_attribute *attr, char *buf)
2609{
2610	struct serial_struct tmp;
2611	struct tty_port *port = dev_get_drvdata(dev);
2612
2613	uart_get_info(port, &tmp);
2614	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16);
2615}
2616
2617static ssize_t uart_get_attr_type(struct device *dev,
2618	struct device_attribute *attr, char *buf)
2619{
2620	struct serial_struct tmp;
2621	struct tty_port *port = dev_get_drvdata(dev);
2622
2623	uart_get_info(port, &tmp);
2624	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type);
2625}
2626static ssize_t uart_get_attr_line(struct device *dev,
 
2627	struct device_attribute *attr, char *buf)
2628{
2629	struct serial_struct tmp;
2630	struct tty_port *port = dev_get_drvdata(dev);
2631
2632	uart_get_info(port, &tmp);
2633	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line);
2634}
2635
2636static ssize_t uart_get_attr_port(struct device *dev,
2637	struct device_attribute *attr, char *buf)
2638{
2639	struct serial_struct tmp;
2640	struct tty_port *port = dev_get_drvdata(dev);
2641	unsigned long ioaddr;
2642
2643	uart_get_info(port, &tmp);
2644	ioaddr = tmp.port;
2645	if (HIGH_BITS_OFFSET)
2646		ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET;
2647	return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr);
2648}
2649
2650static ssize_t uart_get_attr_irq(struct device *dev,
2651	struct device_attribute *attr, char *buf)
2652{
2653	struct serial_struct tmp;
2654	struct tty_port *port = dev_get_drvdata(dev);
2655
2656	uart_get_info(port, &tmp);
2657	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq);
2658}
2659
2660static ssize_t uart_get_attr_flags(struct device *dev,
2661	struct device_attribute *attr, char *buf)
2662{
2663	struct serial_struct tmp;
2664	struct tty_port *port = dev_get_drvdata(dev);
2665
2666	uart_get_info(port, &tmp);
2667	return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags);
2668}
2669
2670static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev,
2671	struct device_attribute *attr, char *buf)
2672{
2673	struct serial_struct tmp;
2674	struct tty_port *port = dev_get_drvdata(dev);
2675
2676	uart_get_info(port, &tmp);
2677	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size);
2678}
2679
2680
2681static ssize_t uart_get_attr_close_delay(struct device *dev,
2682	struct device_attribute *attr, char *buf)
2683{
2684	struct serial_struct tmp;
2685	struct tty_port *port = dev_get_drvdata(dev);
2686
2687	uart_get_info(port, &tmp);
2688	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay);
2689}
2690
2691
2692static ssize_t uart_get_attr_closing_wait(struct device *dev,
2693	struct device_attribute *attr, char *buf)
2694{
2695	struct serial_struct tmp;
2696	struct tty_port *port = dev_get_drvdata(dev);
2697
2698	uart_get_info(port, &tmp);
2699	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait);
2700}
2701
2702static ssize_t uart_get_attr_custom_divisor(struct device *dev,
2703	struct device_attribute *attr, char *buf)
2704{
2705	struct serial_struct tmp;
2706	struct tty_port *port = dev_get_drvdata(dev);
2707
2708	uart_get_info(port, &tmp);
2709	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor);
2710}
2711
2712static ssize_t uart_get_attr_io_type(struct device *dev,
2713	struct device_attribute *attr, char *buf)
2714{
2715	struct serial_struct tmp;
2716	struct tty_port *port = dev_get_drvdata(dev);
2717
2718	uart_get_info(port, &tmp);
2719	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type);
2720}
2721
2722static ssize_t uart_get_attr_iomem_base(struct device *dev,
2723	struct device_attribute *attr, char *buf)
2724{
2725	struct serial_struct tmp;
2726	struct tty_port *port = dev_get_drvdata(dev);
2727
2728	uart_get_info(port, &tmp);
2729	return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base);
2730}
2731
2732static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
2733	struct device_attribute *attr, char *buf)
2734{
2735	struct serial_struct tmp;
2736	struct tty_port *port = dev_get_drvdata(dev);
2737
2738	uart_get_info(port, &tmp);
2739	return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2740}
2741
2742static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
2743static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
2744static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
2745static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL);
2746static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL);
2747static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL);
2748static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL);
2749static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL);
2750static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL);
2751static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL);
2752static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
2753static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
2754static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2755
2756static struct attribute *tty_dev_attrs[] = {
 
2757	&dev_attr_type.attr,
2758	&dev_attr_line.attr,
2759	&dev_attr_port.attr,
2760	&dev_attr_irq.attr,
2761	&dev_attr_flags.attr,
2762	&dev_attr_xmit_fifo_size.attr,
2763	&dev_attr_uartclk.attr,
2764	&dev_attr_close_delay.attr,
2765	&dev_attr_closing_wait.attr,
2766	&dev_attr_custom_divisor.attr,
2767	&dev_attr_io_type.attr,
2768	&dev_attr_iomem_base.attr,
2769	&dev_attr_iomem_reg_shift.attr,
2770	NULL,
2771	};
 
2772
2773static const struct attribute_group tty_dev_attr_group = {
2774	.attrs = tty_dev_attrs,
2775	};
2776
2777/**
2778 *	uart_add_one_port - attach a driver-defined port structure
2779 *	@drv: pointer to the uart low level driver structure for this port
2780 *	@uport: uart port structure to use for this port.
2781 *
2782 *	This allows the driver to register its own uart_port structure
2783 *	with the core driver.  The main purpose is to allow the low
2784 *	level uart drivers to expand uart_port, rather than having yet
2785 *	more levels of structures.
 
 
2786 */
2787int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
2788{
2789	struct uart_state *state;
2790	struct tty_port *port;
2791	int ret = 0;
2792	struct device *tty_dev;
2793	int num_groups;
2794
2795	BUG_ON(in_interrupt());
2796
2797	if (uport->line >= drv->nr)
2798		return -EINVAL;
2799
2800	state = drv->state + uport->line;
2801	port = &state->port;
2802
2803	mutex_lock(&port_mutex);
2804	mutex_lock(&port->mutex);
2805	if (state->uart_port) {
2806		ret = -EINVAL;
2807		goto out;
2808	}
2809
2810	/* Link the port to the driver state table and vice versa */
2811	atomic_set(&state->refcount, 1);
2812	init_waitqueue_head(&state->remove_wait);
2813	state->uart_port = uport;
2814	uport->state = state;
2815
2816	state->pm_state = UART_PM_STATE_UNDEFINED;
2817	uport->cons = drv->cons;
2818	uport->minor = drv->tty_driver->minor_start + uport->line;
2819	uport->name = kasprintf(GFP_KERNEL, "%s%d", drv->dev_name,
2820				drv->tty_driver->name_base + uport->line);
2821	if (!uport->name) {
2822		ret = -ENOMEM;
2823		goto out;
2824	}
2825
2826	/*
2827	 * If this port is a console, then the spinlock is already
2828	 * initialised.
2829	 */
2830	if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) {
2831		spin_lock_init(&uport->lock);
2832		lockdep_set_class(&uport->lock, &port_lock_key);
2833	}
2834	if (uport->cons && uport->dev)
2835		of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
2836
 
2837	uart_configure_port(drv, state, uport);
2838
2839	port->console = uart_console(uport);
2840
2841	num_groups = 2;
2842	if (uport->attr_group)
2843		num_groups++;
2844
2845	uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups),
2846				    GFP_KERNEL);
2847	if (!uport->tty_groups) {
2848		ret = -ENOMEM;
2849		goto out;
2850	}
2851	uport->tty_groups[0] = &tty_dev_attr_group;
2852	if (uport->attr_group)
2853		uport->tty_groups[1] = uport->attr_group;
2854
2855	/*
2856	 * Register the port whether it's detected or not.  This allows
2857	 * setserial to be used to alter this port's parameters.
2858	 */
2859	tty_dev = tty_port_register_device_attr_serdev(port, drv->tty_driver,
2860			uport->line, uport->dev, port, uport->tty_groups);
 
2861	if (!IS_ERR(tty_dev)) {
2862		device_set_wakeup_capable(tty_dev, 1);
2863	} else {
2864		dev_err(uport->dev, "Cannot register tty device on line %d\n",
2865		       uport->line);
2866	}
2867
2868	/*
2869	 * Ensure UPF_DEAD is not set.
2870	 */
2871	uport->flags &= ~UPF_DEAD;
2872
2873 out:
2874	mutex_unlock(&port->mutex);
2875	mutex_unlock(&port_mutex);
2876
2877	return ret;
2878}
2879
2880/**
2881 *	uart_remove_one_port - detach a driver defined port structure
2882 *	@drv: pointer to the uart low level driver structure for this port
2883 *	@uport: uart port structure for this port
2884 *
2885 *	This unhooks (and hangs up) the specified port structure from the
2886 *	core driver.  No further calls will be made to the low-level code
2887 *	for this port.
 
 
2888 */
2889int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
 
2890{
2891	struct uart_state *state = drv->state + uport->line;
2892	struct tty_port *port = &state->port;
2893	struct uart_port *uart_port;
2894	struct tty_struct *tty;
2895	int ret = 0;
2896
2897	BUG_ON(in_interrupt());
2898
2899	mutex_lock(&port_mutex);
2900
2901	/*
2902	 * Mark the port "dead" - this prevents any opens from
2903	 * succeeding while we shut down the port.
2904	 */
2905	mutex_lock(&port->mutex);
2906	uart_port = uart_port_check(state);
2907	if (uart_port != uport)
2908		dev_alert(uport->dev, "Removing wrong port: %p != %p\n",
2909			  uart_port, uport);
2910
2911	if (!uart_port) {
2912		mutex_unlock(&port->mutex);
2913		ret = -EINVAL;
2914		goto out;
2915	}
2916	uport->flags |= UPF_DEAD;
2917	mutex_unlock(&port->mutex);
2918
2919	/*
2920	 * Remove the devices from the tty layer
2921	 */
2922	tty_port_unregister_device(port, drv->tty_driver, uport->line);
2923
2924	tty = tty_port_tty_get(port);
2925	if (tty) {
2926		tty_vhangup(port->tty);
2927		tty_kref_put(tty);
2928	}
2929
2930	/*
2931	 * If the port is used as a console, unregister it
2932	 */
2933	if (uart_console(uport))
2934		unregister_console(uport->cons);
2935
2936	/*
2937	 * Free the port IO and memory resources, if any.
2938	 */
2939	if (uport->type != PORT_UNKNOWN && uport->ops->release_port)
2940		uport->ops->release_port(uport);
2941	kfree(uport->tty_groups);
2942	kfree(uport->name);
2943
2944	/*
2945	 * Indicate that there isn't a port here anymore.
2946	 */
2947	uport->type = PORT_UNKNOWN;
 
2948
2949	mutex_lock(&port->mutex);
2950	WARN_ON(atomic_dec_return(&state->refcount) < 0);
2951	wait_event(state->remove_wait, !atomic_read(&state->refcount));
2952	state->uart_port = NULL;
2953	mutex_unlock(&port->mutex);
2954out:
2955	mutex_unlock(&port_mutex);
2956
2957	return ret;
2958}
2959
2960/*
2961 *	Are the two ports equivalent?
 
 
 
 
 
2962 */
2963int uart_match_port(struct uart_port *port1, struct uart_port *port2)
 
2964{
2965	if (port1->iotype != port2->iotype)
2966		return 0;
2967
2968	switch (port1->iotype) {
2969	case UPIO_PORT:
2970		return (port1->iobase == port2->iobase);
2971	case UPIO_HUB6:
2972		return (port1->iobase == port2->iobase) &&
2973		       (port1->hub6   == port2->hub6);
2974	case UPIO_MEM:
2975	case UPIO_MEM16:
2976	case UPIO_MEM32:
2977	case UPIO_MEM32BE:
2978	case UPIO_AU:
2979	case UPIO_TSI:
2980		return (port1->mapbase == port2->mapbase);
2981	}
2982	return 0;
 
2983}
2984EXPORT_SYMBOL(uart_match_port);
2985
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2986/**
2987 *	uart_handle_dcd_change - handle a change of carrier detect state
2988 *	@uport: uart_port structure for the open port
2989 *	@status: new carrier detect status, nonzero if active
2990 *
2991 *	Caller must hold uport->lock
2992 */
2993void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
2994{
2995	struct tty_port *port = &uport->state->port;
2996	struct tty_struct *tty = port->tty;
2997	struct tty_ldisc *ld;
2998
2999	lockdep_assert_held_once(&uport->lock);
3000
3001	if (tty) {
3002		ld = tty_ldisc_ref(tty);
3003		if (ld) {
3004			if (ld->ops->dcd_change)
3005				ld->ops->dcd_change(tty, status);
3006			tty_ldisc_deref(ld);
3007		}
3008	}
3009
3010	uport->icount.dcd++;
3011
3012	if (uart_dcd_enabled(uport)) {
3013		if (status)
3014			wake_up_interruptible(&port->open_wait);
3015		else if (tty)
3016			tty_hangup(tty);
3017	}
3018}
3019EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
3020
3021/**
3022 *	uart_handle_cts_change - handle a change of clear-to-send state
3023 *	@uport: uart_port structure for the open port
3024 *	@status: new clear to send status, nonzero if active
3025 *
3026 *	Caller must hold uport->lock
3027 */
3028void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
3029{
3030	lockdep_assert_held_once(&uport->lock);
3031
3032	uport->icount.cts++;
3033
3034	if (uart_softcts_mode(uport)) {
3035		if (uport->hw_stopped) {
3036			if (status) {
3037				uport->hw_stopped = 0;
3038				uport->ops->start_tx(uport);
3039				uart_write_wakeup(uport);
3040			}
3041		} else {
3042			if (!status) {
3043				uport->hw_stopped = 1;
3044				uport->ops->stop_tx(uport);
3045			}
3046		}
3047
3048	}
3049}
3050EXPORT_SYMBOL_GPL(uart_handle_cts_change);
3051
3052/**
3053 * uart_insert_char - push a char to the uart layer
3054 *
3055 * User is responsible to call tty_flip_buffer_push when they are done with
3056 * insertion.
3057 *
3058 * @port: corresponding port
3059 * @status: state of the serial port RX buffer (LSR for 8250)
3060 * @overrun: mask of overrun bits in @status
3061 * @ch: character to push
3062 * @flag: flag for the character (see TTY_NORMAL and friends)
3063 */
3064void uart_insert_char(struct uart_port *port, unsigned int status,
3065		 unsigned int overrun, unsigned int ch, unsigned int flag)
3066{
3067	struct tty_port *tport = &port->state->port;
3068
3069	if ((status & port->ignore_status_mask & ~overrun) == 0)
3070		if (tty_insert_flip_char(tport, ch, flag) == 0)
3071			++port->icount.buf_overrun;
3072
3073	/*
3074	 * Overrun is special.  Since it's reported immediately,
3075	 * it doesn't affect the current character.
3076	 */
3077	if (status & ~port->ignore_status_mask & overrun)
3078		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
3079			++port->icount.buf_overrun;
3080}
3081EXPORT_SYMBOL_GPL(uart_insert_char);
3082
3083EXPORT_SYMBOL(uart_write_wakeup);
3084EXPORT_SYMBOL(uart_register_driver);
3085EXPORT_SYMBOL(uart_unregister_driver);
3086EXPORT_SYMBOL(uart_suspend_port);
3087EXPORT_SYMBOL(uart_resume_port);
3088EXPORT_SYMBOL(uart_add_one_port);
3089EXPORT_SYMBOL(uart_remove_one_port);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3090
3091/**
3092 * uart_get_rs485_mode() - retrieve rs485 properties for given uart
3093 * @dev: uart device
3094 * @rs485conf: output parameter
3095 *
3096 * This function implements the device tree binding described in
3097 * Documentation/devicetree/bindings/serial/rs485.txt.
3098 */
3099void uart_get_rs485_mode(struct device *dev, struct serial_rs485 *rs485conf)
3100{
 
 
 
 
3101	u32 rs485_delay[2];
3102	int ret;
3103
 
 
 
3104	ret = device_property_read_u32_array(dev, "rs485-rts-delay",
3105					     rs485_delay, 2);
3106	if (!ret) {
3107		rs485conf->delay_rts_before_send = rs485_delay[0];
3108		rs485conf->delay_rts_after_send = rs485_delay[1];
3109	} else {
3110		rs485conf->delay_rts_before_send = 0;
3111		rs485conf->delay_rts_after_send = 0;
3112	}
3113
 
 
3114	/*
3115	 * Clear full-duplex and enabled flags, set RTS polarity to active high
3116	 * to get to a defined state with the following properties:
3117	 */
3118	rs485conf->flags &= ~(SER_RS485_RX_DURING_TX | SER_RS485_ENABLED |
 
3119			      SER_RS485_RTS_AFTER_SEND);
3120	rs485conf->flags |= SER_RS485_RTS_ON_SEND;
3121
3122	if (device_property_read_bool(dev, "rs485-rx-during-tx"))
3123		rs485conf->flags |= SER_RS485_RX_DURING_TX;
3124
3125	if (device_property_read_bool(dev, "linux,rs485-enabled-at-boot-time"))
3126		rs485conf->flags |= SER_RS485_ENABLED;
3127
3128	if (device_property_read_bool(dev, "rs485-rts-active-low")) {
3129		rs485conf->flags &= ~SER_RS485_RTS_ON_SEND;
3130		rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
3131	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3132}
3133EXPORT_SYMBOL_GPL(uart_get_rs485_mode);
 
 
 
 
 
 
 
 
3134
3135MODULE_DESCRIPTION("Serial driver core");
3136MODULE_LICENSE("GPL");