1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Serial driver for the amiga builtin port.
   4 *
   5 * This code was created by taking serial.c version 4.30 from kernel
   6 * release 2.3.22, replacing all hardware related stuff with the
   7 * corresponding amiga hardware actions, and removing all irrelevant
   8 * code. As a consequence, it uses many of the constants and names
   9 * associated with the registers and bits of 16550 compatible UARTS -
  10 * but only to keep track of status, etc in the state variables. It
  11 * was done this was to make it easier to keep the code in line with
  12 * (non hardware specific) changes to serial.c.
  13 *
  14 * The port is registered with the tty driver as minor device 64, and
  15 * therefore other ports should should only use 65 upwards.
  16 *
  17 * Richard Lucock 28/12/99
  18 *
  19 *  Copyright (C) 1991, 1992  Linus Torvalds
  20 *  Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 
  21 * 		1998, 1999  Theodore Ts'o
  22 *
  23 */
  24
  25/*
  26 * Serial driver configuration section.  Here are the various options:
  27 *
  28 * SERIAL_PARANOIA_CHECK
  29 * 		Check the magic number for the async_structure where
  30 * 		ever possible.
  31 */
  32
  33#include <linux/delay.h>
  34
  35#undef SERIAL_PARANOIA_CHECK
  36
  37/* Set of debugging defines */
  38
  39#undef SERIAL_DEBUG_INTR
  40#undef SERIAL_DEBUG_OPEN
  41#undef SERIAL_DEBUG_FLOW
  42#undef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
  43
  44/* Sanity checks */
  45
  46#if defined(MODULE) && defined(SERIAL_DEBUG_MCOUNT)
  47#define DBG_CNT(s) printk("(%s): [%x] refc=%d, serc=%d, ttyc=%d -> %s\n", \
  48 tty->name, (info->tport.flags), serial_driver->refcount,info->count,tty->count,s)
  49#else
  50#define DBG_CNT(s)
  51#endif
  52
  53/*
  54 * End of serial driver configuration section.
  55 */
  56
  57#include <linux/module.h>
  58
  59#include <linux/types.h>
  60#include <linux/serial.h>
  61#include <linux/serial_reg.h>
  62static char *serial_version = "4.30";
  63
  64#include <linux/errno.h>
  65#include <linux/signal.h>
  66#include <linux/sched.h>
  67#include <linux/kernel.h>
  68#include <linux/timer.h>
  69#include <linux/interrupt.h>
  70#include <linux/tty.h>
  71#include <linux/tty_flip.h>
  72#include <linux/circ_buf.h>
  73#include <linux/console.h>
  74#include <linux/major.h>
  75#include <linux/string.h>
  76#include <linux/fcntl.h>
  77#include <linux/ptrace.h>
  78#include <linux/ioport.h>
  79#include <linux/mm.h>
  80#include <linux/seq_file.h>
  81#include <linux/slab.h>
  82#include <linux/init.h>
  83#include <linux/bitops.h>
  84#include <linux/platform_device.h>
  85
  86#include <asm/setup.h>
  87
  88
  89#include <asm/irq.h>
  90
  91#include <asm/amigahw.h>
  92#include <asm/amigaints.h>
  93
  94struct serial_state {
  95	struct tty_port		tport;
  96	struct circ_buf		xmit;
  97	struct async_icount	icount;
  98
  99	unsigned long		port;
 100	int			baud_base;
 101	int			xmit_fifo_size;
 102	int			custom_divisor;
 103	int			read_status_mask;
 104	int			ignore_status_mask;
 105	int			timeout;
 106	int			quot;
 107	int			IER; 	/* Interrupt Enable Register */
 108	int			MCR; 	/* Modem control register */
 109	int			x_char;	/* xon/xoff character */
 110};
 111
 112#define custom amiga_custom
 113static char *serial_name = "Amiga-builtin serial driver";
 114
 115static struct tty_driver *serial_driver;
 116
 117/* number of characters left in xmit buffer before we ask for more */
 118#define WAKEUP_CHARS 256
 119
 120static unsigned char current_ctl_bits;
 121
 122static void change_speed(struct tty_struct *tty, struct serial_state *info,
 123		struct ktermios *old);
 124static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
 125
 126
 127static struct serial_state rs_table[1];
 128
 129#define NR_PORTS ARRAY_SIZE(rs_table)
 130
 131#include <linux/uaccess.h>
 132
 133#define serial_isroot()	(capable(CAP_SYS_ADMIN))
 134
 135
 136static inline int serial_paranoia_check(struct serial_state *info,
 137					char *name, const char *routine)
 138{
 139#ifdef SERIAL_PARANOIA_CHECK
 140	static const char *badmagic =
 141		"Warning: bad magic number for serial struct (%s) in %s\n";
 142	static const char *badinfo =
 143		"Warning: null async_struct for (%s) in %s\n";
 144
 145	if (!info) {
 146		printk(badinfo, name, routine);
 147		return 1;
 148	}
 149	if (info->magic != SERIAL_MAGIC) {
 150		printk(badmagic, name, routine);
 151		return 1;
 152	}
 153#endif
 154	return 0;
 155}
 156
 157/* some serial hardware definitions */
 158#define SDR_OVRUN   (1<<15)
 159#define SDR_RBF     (1<<14)
 160#define SDR_TBE     (1<<13)
 161#define SDR_TSRE    (1<<12)
 162
 163#define SERPER_PARENB    (1<<15)
 164
 165#define AC_SETCLR   (1<<15)
 166#define AC_UARTBRK  (1<<11)
 167
 168#define SER_DTR     (1<<7)
 169#define SER_RTS     (1<<6)
 170#define SER_DCD     (1<<5)
 171#define SER_CTS     (1<<4)
 172#define SER_DSR     (1<<3)
 173
 174static __inline__ void rtsdtr_ctrl(int bits)
 175{
 176    ciab.pra = ((bits & (SER_RTS | SER_DTR)) ^ (SER_RTS | SER_DTR)) | (ciab.pra & ~(SER_RTS | SER_DTR));
 177}
 178
 179/*
 180 * ------------------------------------------------------------
 181 * rs_stop() and rs_start()
 182 *
 183 * This routines are called before setting or resetting tty->stopped.
 184 * They enable or disable transmitter interrupts, as necessary.
 185 * ------------------------------------------------------------
 186 */
 187static void rs_stop(struct tty_struct *tty)
 188{
 189	struct serial_state *info = tty->driver_data;
 190	unsigned long flags;
 191
 192	if (serial_paranoia_check(info, tty->name, "rs_stop"))
 193		return;
 194
 195	local_irq_save(flags);
 196	if (info->IER & UART_IER_THRI) {
 197		info->IER &= ~UART_IER_THRI;
 198		/* disable Tx interrupt and remove any pending interrupts */
 199		custom.intena = IF_TBE;
 200		mb();
 201		custom.intreq = IF_TBE;
 202		mb();
 203	}
 204	local_irq_restore(flags);
 205}
 206
 207static void rs_start(struct tty_struct *tty)
 208{
 209	struct serial_state *info = tty->driver_data;
 210	unsigned long flags;
 211
 212	if (serial_paranoia_check(info, tty->name, "rs_start"))
 213		return;
 214
 215	local_irq_save(flags);
 216	if (info->xmit.head != info->xmit.tail
 217	    && info->xmit.buf
 218	    && !(info->IER & UART_IER_THRI)) {
 219		info->IER |= UART_IER_THRI;
 220		custom.intena = IF_SETCLR | IF_TBE;
 221		mb();
 222		/* set a pending Tx Interrupt, transmitter should restart now */
 223		custom.intreq = IF_SETCLR | IF_TBE;
 224		mb();
 225	}
 226	local_irq_restore(flags);
 227}
 228
 229/*
 230 * ----------------------------------------------------------------------
 231 *
 232 * Here starts the interrupt handling routines.  All of the following
 233 * subroutines are declared as inline and are folded into
 234 * rs_interrupt().  They were separated out for readability's sake.
 235 *
 236 * Note: rs_interrupt() is a "fast" interrupt, which means that it
 237 * runs with interrupts turned off.  People who may want to modify
 238 * rs_interrupt() should try to keep the interrupt handler as fast as
 239 * possible.  After you are done making modifications, it is not a bad
 240 * idea to do:
 241 * 
 242 * gcc -S -DKERNEL -Wall -Wstrict-prototypes -O6 -fomit-frame-pointer serial.c
 243 *
 244 * and look at the resulting assemble code in serial.s.
 245 *
 246 * 				- Ted Ts'o (tytso@mit.edu), 7-Mar-93
 247 * -----------------------------------------------------------------------
 248 */
 249
 250static void receive_chars(struct serial_state *info)
 251{
 252        int status;
 253	int serdatr;
 254	unsigned char ch, flag;
 255	struct	async_icount *icount;
 256	int oe = 0;
 257
 258	icount = &info->icount;
 259
 260	status = UART_LSR_DR; /* We obviously have a character! */
 261	serdatr = custom.serdatr;
 262	mb();
 263	custom.intreq = IF_RBF;
 264	mb();
 265
 266	if((serdatr & 0x1ff) == 0)
 267	    status |= UART_LSR_BI;
 268	if(serdatr & SDR_OVRUN)
 269	    status |= UART_LSR_OE;
 270
 271	ch = serdatr & 0xff;
 272	icount->rx++;
 273
 274#ifdef SERIAL_DEBUG_INTR
 275	printk("DR%02x:%02x...", ch, status);
 276#endif
 277	flag = TTY_NORMAL;
 278
 279	/*
 280	 * We don't handle parity or frame errors - but I have left
 281	 * the code in, since I'm not sure that the errors can't be
 282	 * detected.
 283	 */
 284
 285	if (status & (UART_LSR_BI | UART_LSR_PE |
 286		      UART_LSR_FE | UART_LSR_OE)) {
 287	  /*
 288	   * For statistics only
 289	   */
 290	  if (status & UART_LSR_BI) {
 291	    status &= ~(UART_LSR_FE | UART_LSR_PE);
 292	    icount->brk++;
 293	  } else if (status & UART_LSR_PE)
 294	    icount->parity++;
 295	  else if (status & UART_LSR_FE)
 296	    icount->frame++;
 297	  if (status & UART_LSR_OE)
 298	    icount->overrun++;
 299
 300	  /*
 301	   * Now check to see if character should be
 302	   * ignored, and mask off conditions which
 303	   * should be ignored.
 304	   */
 305	  if (status & info->ignore_status_mask)
 306	    goto out;
 307
 308	  status &= info->read_status_mask;
 309
 310	  if (status & (UART_LSR_BI)) {
 311#ifdef SERIAL_DEBUG_INTR
 312	    printk("handling break....");
 313#endif
 314	    flag = TTY_BREAK;
 315	    if (info->tport.flags & ASYNC_SAK)
 316	      do_SAK(info->tport.tty);
 317	  } else if (status & UART_LSR_PE)
 318	    flag = TTY_PARITY;
 319	  else if (status & UART_LSR_FE)
 320	    flag = TTY_FRAME;
 321	  if (status & UART_LSR_OE) {
 322	    /*
 323	     * Overrun is special, since it's
 324	     * reported immediately, and doesn't
 325	     * affect the current character
 326	     */
 327	     oe = 1;
 328	  }
 329	}
 330	tty_insert_flip_char(&info->tport, ch, flag);
 331	if (oe == 1)
 332		tty_insert_flip_char(&info->tport, 0, TTY_OVERRUN);
 333	tty_flip_buffer_push(&info->tport);
 334out:
 335	return;
 336}
 337
 338static void transmit_chars(struct serial_state *info)
 339{
 340	custom.intreq = IF_TBE;
 341	mb();
 342	if (info->x_char) {
 343	        custom.serdat = info->x_char | 0x100;
 344		mb();
 345		info->icount.tx++;
 346		info->x_char = 0;
 347		return;
 348	}
 349	if (info->xmit.head == info->xmit.tail
 350	    || info->tport.tty->stopped
 351	    || info->tport.tty->hw_stopped) {
 352		info->IER &= ~UART_IER_THRI;
 353	        custom.intena = IF_TBE;
 354		mb();
 355		return;
 356	}
 357
 358	custom.serdat = info->xmit.buf[info->xmit.tail++] | 0x100;
 359	mb();
 360	info->xmit.tail = info->xmit.tail & (SERIAL_XMIT_SIZE-1);
 361	info->icount.tx++;
 362
 363	if (CIRC_CNT(info->xmit.head,
 364		     info->xmit.tail,
 365		     SERIAL_XMIT_SIZE) < WAKEUP_CHARS)
 366		tty_wakeup(info->tport.tty);
 367
 368#ifdef SERIAL_DEBUG_INTR
 369	printk("THRE...");
 370#endif
 371	if (info->xmit.head == info->xmit.tail) {
 372	        custom.intena = IF_TBE;
 373		mb();
 374		info->IER &= ~UART_IER_THRI;
 375	}
 376}
 377
 378static void check_modem_status(struct serial_state *info)
 379{
 380	struct tty_port *port = &info->tport;
 381	unsigned char status = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
 382	unsigned char dstatus;
 383	struct	async_icount *icount;
 384
 385	/* Determine bits that have changed */
 386	dstatus = status ^ current_ctl_bits;
 387	current_ctl_bits = status;
 388
 389	if (dstatus) {
 390		icount = &info->icount;
 391		/* update input line counters */
 392		if (dstatus & SER_DSR)
 393			icount->dsr++;
 394		if (dstatus & SER_DCD) {
 395			icount->dcd++;
 396		}
 397		if (dstatus & SER_CTS)
 398			icount->cts++;
 399		wake_up_interruptible(&port->delta_msr_wait);
 400	}
 401
 402	if (tty_port_check_carrier(port) && (dstatus & SER_DCD)) {
 403#if (defined(SERIAL_DEBUG_OPEN) || defined(SERIAL_DEBUG_INTR))
 404		printk("ttyS%d CD now %s...", info->line,
 405		       (!(status & SER_DCD)) ? "on" : "off");
 406#endif
 407		if (!(status & SER_DCD))
 408			wake_up_interruptible(&port->open_wait);
 409		else {
 410#ifdef SERIAL_DEBUG_OPEN
 411			printk("doing serial hangup...");
 412#endif
 413			if (port->tty)
 414				tty_hangup(port->tty);
 415		}
 416	}
 417	if (tty_port_cts_enabled(port)) {
 418		if (port->tty->hw_stopped) {
 419			if (!(status & SER_CTS)) {
 420#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
 421				printk("CTS tx start...");
 422#endif
 423				port->tty->hw_stopped = 0;
 424				info->IER |= UART_IER_THRI;
 425				custom.intena = IF_SETCLR | IF_TBE;
 426				mb();
 427				/* set a pending Tx Interrupt, transmitter should restart now */
 428				custom.intreq = IF_SETCLR | IF_TBE;
 429				mb();
 430				tty_wakeup(port->tty);
 431				return;
 432			}
 433		} else {
 434			if ((status & SER_CTS)) {
 435#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
 436				printk("CTS tx stop...");
 437#endif
 438				port->tty->hw_stopped = 1;
 439				info->IER &= ~UART_IER_THRI;
 440				/* disable Tx interrupt and remove any pending interrupts */
 441				custom.intena = IF_TBE;
 442				mb();
 443				custom.intreq = IF_TBE;
 444				mb();
 445			}
 446		}
 447	}
 448}
 449
 450static irqreturn_t ser_vbl_int( int irq, void *data)
 451{
 452        /* vbl is just a periodic interrupt we tie into to update modem status */
 453	struct serial_state *info = data;
 454	/*
 455	 * TBD - is it better to unregister from this interrupt or to
 456	 * ignore it if MSI is clear ?
 457	 */
 458	if(info->IER & UART_IER_MSI)
 459	  check_modem_status(info);
 460	return IRQ_HANDLED;
 461}
 462
 463static irqreturn_t ser_rx_int(int irq, void *dev_id)
 464{
 465	struct serial_state *info = dev_id;
 466
 467#ifdef SERIAL_DEBUG_INTR
 468	printk("ser_rx_int...");
 469#endif
 470
 471	if (!info->tport.tty)
 472		return IRQ_NONE;
 473
 474	receive_chars(info);
 475#ifdef SERIAL_DEBUG_INTR
 476	printk("end.\n");
 477#endif
 478	return IRQ_HANDLED;
 479}
 480
 481static irqreturn_t ser_tx_int(int irq, void *dev_id)
 482{
 483	struct serial_state *info = dev_id;
 484
 485	if (custom.serdatr & SDR_TBE) {
 486#ifdef SERIAL_DEBUG_INTR
 487	  printk("ser_tx_int...");
 488#endif
 489
 490	  if (!info->tport.tty)
 491		return IRQ_NONE;
 492
 493	  transmit_chars(info);
 494#ifdef SERIAL_DEBUG_INTR
 495	  printk("end.\n");
 496#endif
 497	}
 498	return IRQ_HANDLED;
 499}
 500
 501/*
 502 * -------------------------------------------------------------------
 503 * Here ends the serial interrupt routines.
 504 * -------------------------------------------------------------------
 505 */
 506
 507/*
 508 * ---------------------------------------------------------------
 509 * Low level utility subroutines for the serial driver:  routines to
 510 * figure out the appropriate timeout for an interrupt chain, routines
 511 * to initialize and startup a serial port, and routines to shutdown a
 512 * serial port.  Useful stuff like that.
 513 * ---------------------------------------------------------------
 514 */
 515
 516static int startup(struct tty_struct *tty, struct serial_state *info)
 517{
 518	struct tty_port *port = &info->tport;
 519	unsigned long flags;
 520	int	retval=0;
 521	unsigned long page;
 522
 523	page = get_zeroed_page(GFP_KERNEL);
 524	if (!page)
 525		return -ENOMEM;
 526
 527	local_irq_save(flags);
 528
 529	if (tty_port_initialized(port)) {
 530		free_page(page);
 531		goto errout;
 532	}
 533
 534	if (info->xmit.buf)
 535		free_page(page);
 536	else
 537		info->xmit.buf = (unsigned char *) page;
 538
 539#ifdef SERIAL_DEBUG_OPEN
 540	printk("starting up ttys%d ...", info->line);
 541#endif
 542
 543	/* Clear anything in the input buffer */
 544
 545	custom.intreq = IF_RBF;
 546	mb();
 547
 548	retval = request_irq(IRQ_AMIGA_VERTB, ser_vbl_int, 0, "serial status", info);
 549	if (retval) {
 550	  if (serial_isroot()) {
 551	      set_bit(TTY_IO_ERROR, &tty->flags);
 552	    retval = 0;
 553	  }
 554	  goto errout;
 555	}
 556
 557	/* enable both Rx and Tx interrupts */
 558	custom.intena = IF_SETCLR | IF_RBF | IF_TBE;
 559	mb();
 560	info->IER = UART_IER_MSI;
 561
 562	/* remember current state of the DCD and CTS bits */
 563	current_ctl_bits = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
 564
 565	info->MCR = 0;
 566	if (C_BAUD(tty))
 567	  info->MCR = SER_DTR | SER_RTS;
 568	rtsdtr_ctrl(info->MCR);
 569
 570	clear_bit(TTY_IO_ERROR, &tty->flags);
 571	info->xmit.head = info->xmit.tail = 0;
 572
 573	/*
 574	 * and set the speed of the serial port
 575	 */
 576	change_speed(tty, info, NULL);
 577
 578	tty_port_set_initialized(port, 1);
 579	local_irq_restore(flags);
 580	return 0;
 581
 582errout:
 583	local_irq_restore(flags);
 584	return retval;
 585}
 586
 587/*
 588 * This routine will shutdown a serial port; interrupts are disabled, and
 589 * DTR is dropped if the hangup on close termio flag is on.
 590 */
 591static void shutdown(struct tty_struct *tty, struct serial_state *info)
 592{
 593	unsigned long	flags;
 594	struct serial_state *state;
 595
 596	if (!tty_port_initialized(&info->tport))
 597		return;
 598
 599	state = info;
 600
 601#ifdef SERIAL_DEBUG_OPEN
 602	printk("Shutting down serial port %d ....\n", info->line);
 603#endif
 604
 605	local_irq_save(flags); /* Disable interrupts */
 606
 607	/*
 608	 * clear delta_msr_wait queue to avoid mem leaks: we may free the irq
 609	 * here so the queue might never be waken up
 610	 */
 611	wake_up_interruptible(&info->tport.delta_msr_wait);
 612
 613	/*
 614	 * Free the IRQ, if necessary
 615	 */
 616	free_irq(IRQ_AMIGA_VERTB, info);
 617
 618	if (info->xmit.buf) {
 619		free_page((unsigned long) info->xmit.buf);
 620		info->xmit.buf = NULL;
 621	}
 622
 623	info->IER = 0;
 624	custom.intena = IF_RBF | IF_TBE;
 625	mb();
 626
 627	/* disable break condition */
 628	custom.adkcon = AC_UARTBRK;
 629	mb();
 630
 631	if (C_HUPCL(tty))
 632		info->MCR &= ~(SER_DTR|SER_RTS);
 633	rtsdtr_ctrl(info->MCR);
 634
 635	set_bit(TTY_IO_ERROR, &tty->flags);
 636
 637	tty_port_set_initialized(&info->tport, 0);
 638	local_irq_restore(flags);
 639}
 640
 641
 642/*
 643 * This routine is called to set the UART divisor registers to match
 644 * the specified baud rate for a serial port.
 645 */
 646static void change_speed(struct tty_struct *tty, struct serial_state *info,
 647			 struct ktermios *old_termios)
 648{
 649	struct tty_port *port = &info->tport;
 650	int	quot = 0, baud_base, baud;
 651	unsigned cflag, cval = 0;
 652	int	bits;
 653	unsigned long	flags;
 654
 655	cflag = tty->termios.c_cflag;
 656
 657	/* Byte size is always 8 bits plus parity bit if requested */
 658
 659	cval = 3; bits = 10;
 660	if (cflag & CSTOPB) {
 661		cval |= 0x04;
 662		bits++;
 663	}
 664	if (cflag & PARENB) {
 665		cval |= UART_LCR_PARITY;
 666		bits++;
 667	}
 668	if (!(cflag & PARODD))
 669		cval |= UART_LCR_EPAR;
 670#ifdef CMSPAR
 671	if (cflag & CMSPAR)
 672		cval |= UART_LCR_SPAR;
 673#endif
 674
 675	/* Determine divisor based on baud rate */
 676	baud = tty_get_baud_rate(tty);
 677	if (!baud)
 678		baud = 9600;	/* B0 transition handled in rs_set_termios */
 679	baud_base = info->baud_base;
 680	if (baud == 38400 && (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
 681		quot = info->custom_divisor;
 682	else {
 683		if (baud == 134)
 684			/* Special case since 134 is really 134.5 */
 685			quot = (2*baud_base / 269);
 686		else if (baud)
 687			quot = baud_base / baud;
 688	}
 689	/* If the quotient is zero refuse the change */
 690	if (!quot && old_termios) {
 691		/* FIXME: Will need updating for new tty in the end */
 692		tty->termios.c_cflag &= ~CBAUD;
 693		tty->termios.c_cflag |= (old_termios->c_cflag & CBAUD);
 694		baud = tty_get_baud_rate(tty);
 695		if (!baud)
 696			baud = 9600;
 697		if (baud == 38400 &&
 698		    (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
 699			quot = info->custom_divisor;
 700		else {
 701			if (baud == 134)
 702				/* Special case since 134 is really 134.5 */
 703				quot = (2*baud_base / 269);
 704			else if (baud)
 705				quot = baud_base / baud;
 706		}
 707	}
 708	/* As a last resort, if the quotient is zero, default to 9600 bps */
 709	if (!quot)
 710		quot = baud_base / 9600;
 711	info->quot = quot;
 712	info->timeout = ((info->xmit_fifo_size*HZ*bits*quot) / baud_base);
 713	info->timeout += HZ/50;		/* Add .02 seconds of slop */
 714
 715	/* CTS flow control flag and modem status interrupts */
 716	info->IER &= ~UART_IER_MSI;
 717	if (port->flags & ASYNC_HARDPPS_CD)
 718		info->IER |= UART_IER_MSI;
 719	tty_port_set_cts_flow(port, cflag & CRTSCTS);
 720	if (cflag & CRTSCTS)
 721		info->IER |= UART_IER_MSI;
 722	tty_port_set_check_carrier(port, ~cflag & CLOCAL);
 723	if (~cflag & CLOCAL)
 724		info->IER |= UART_IER_MSI;
 725	/* TBD:
 726	 * Does clearing IER_MSI imply that we should disable the VBL interrupt ?
 727	 */
 728
 729	/*
 730	 * Set up parity check flag
 731	 */
 732
 733	info->read_status_mask = UART_LSR_OE | UART_LSR_DR;
 734	if (I_INPCK(tty))
 735		info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
 736	if (I_BRKINT(tty) || I_PARMRK(tty))
 737		info->read_status_mask |= UART_LSR_BI;
 738
 739	/*
 740	 * Characters to ignore
 741	 */
 742	info->ignore_status_mask = 0;
 743	if (I_IGNPAR(tty))
 744		info->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
 745	if (I_IGNBRK(tty)) {
 746		info->ignore_status_mask |= UART_LSR_BI;
 747		/*
 748		 * If we're ignore parity and break indicators, ignore 
 749		 * overruns too.  (For real raw support).
 750		 */
 751		if (I_IGNPAR(tty))
 752			info->ignore_status_mask |= UART_LSR_OE;
 753	}
 754	/*
 755	 * !!! ignore all characters if CREAD is not set
 756	 */
 757	if ((cflag & CREAD) == 0)
 758		info->ignore_status_mask |= UART_LSR_DR;
 759	local_irq_save(flags);
 760
 761	{
 762	  short serper;
 763
 764	/* Set up the baud rate */
 765	  serper = quot - 1;
 766
 767	/* Enable or disable parity bit */
 768
 769	if(cval & UART_LCR_PARITY)
 770	  serper |= (SERPER_PARENB);
 771
 772	custom.serper = serper;
 773	mb();
 774	}
 775
 776	local_irq_restore(flags);
 777}
 778
 779static int rs_put_char(struct tty_struct *tty, unsigned char ch)
 780{
 781	struct serial_state *info;
 782	unsigned long flags;
 783
 784	info = tty->driver_data;
 785
 786	if (serial_paranoia_check(info, tty->name, "rs_put_char"))
 787		return 0;
 788
 789	if (!info->xmit.buf)
 790		return 0;
 791
 792	local_irq_save(flags);
 793	if (CIRC_SPACE(info->xmit.head,
 794		       info->xmit.tail,
 795		       SERIAL_XMIT_SIZE) == 0) {
 796		local_irq_restore(flags);
 797		return 0;
 798	}
 799
 800	info->xmit.buf[info->xmit.head++] = ch;
 801	info->xmit.head &= SERIAL_XMIT_SIZE-1;
 802	local_irq_restore(flags);
 803	return 1;
 804}
 805
 806static void rs_flush_chars(struct tty_struct *tty)
 807{
 808	struct serial_state *info = tty->driver_data;
 809	unsigned long flags;
 810
 811	if (serial_paranoia_check(info, tty->name, "rs_flush_chars"))
 812		return;
 813
 814	if (info->xmit.head == info->xmit.tail
 815	    || tty->stopped
 816	    || tty->hw_stopped
 817	    || !info->xmit.buf)
 818		return;
 819
 820	local_irq_save(flags);
 821	info->IER |= UART_IER_THRI;
 822	custom.intena = IF_SETCLR | IF_TBE;
 823	mb();
 824	/* set a pending Tx Interrupt, transmitter should restart now */
 825	custom.intreq = IF_SETCLR | IF_TBE;
 826	mb();
 827	local_irq_restore(flags);
 828}
 829
 830static int rs_write(struct tty_struct * tty, const unsigned char *buf, int count)
 831{
 832	int	c, ret = 0;
 833	struct serial_state *info = tty->driver_data;
 834	unsigned long flags;
 835
 836	if (serial_paranoia_check(info, tty->name, "rs_write"))
 837		return 0;
 838
 839	if (!info->xmit.buf)
 840		return 0;
 841
 842	local_irq_save(flags);
 843	while (1) {
 844		c = CIRC_SPACE_TO_END(info->xmit.head,
 845				      info->xmit.tail,
 846				      SERIAL_XMIT_SIZE);
 847		if (count < c)
 848			c = count;
 849		if (c <= 0) {
 850			break;
 851		}
 852		memcpy(info->xmit.buf + info->xmit.head, buf, c);
 853		info->xmit.head = ((info->xmit.head + c) &
 854				   (SERIAL_XMIT_SIZE-1));
 855		buf += c;
 856		count -= c;
 857		ret += c;
 858	}
 859	local_irq_restore(flags);
 860
 861	if (info->xmit.head != info->xmit.tail
 862	    && !tty->stopped
 863	    && !tty->hw_stopped
 864	    && !(info->IER & UART_IER_THRI)) {
 865		info->IER |= UART_IER_THRI;
 866		local_irq_disable();
 867		custom.intena = IF_SETCLR | IF_TBE;
 868		mb();
 869		/* set a pending Tx Interrupt, transmitter should restart now */
 870		custom.intreq = IF_SETCLR | IF_TBE;
 871		mb();
 872		local_irq_restore(flags);
 873	}
 874	return ret;
 875}
 876
 877static int rs_write_room(struct tty_struct *tty)
 878{
 879	struct serial_state *info = tty->driver_data;
 880
 881	if (serial_paranoia_check(info, tty->name, "rs_write_room"))
 882		return 0;
 883	return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
 884}
 885
 886static int rs_chars_in_buffer(struct tty_struct *tty)
 887{
 888	struct serial_state *info = tty->driver_data;
 889
 890	if (serial_paranoia_check(info, tty->name, "rs_chars_in_buffer"))
 891		return 0;
 892	return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
 893}
 894
 895static void rs_flush_buffer(struct tty_struct *tty)
 896{
 897	struct serial_state *info = tty->driver_data;
 898	unsigned long flags;
 899
 900	if (serial_paranoia_check(info, tty->name, "rs_flush_buffer"))
 901		return;
 902	local_irq_save(flags);
 903	info->xmit.head = info->xmit.tail = 0;
 904	local_irq_restore(flags);
 905	tty_wakeup(tty);
 906}
 907
 908/*
 909 * This function is used to send a high-priority XON/XOFF character to
 910 * the device
 911 */
 912static void rs_send_xchar(struct tty_struct *tty, char ch)
 913{
 914	struct serial_state *info = tty->driver_data;
 915        unsigned long flags;
 916
 917	if (serial_paranoia_check(info, tty->name, "rs_send_xchar"))
 918		return;
 919
 920	info->x_char = ch;
 921	if (ch) {
 922		/* Make sure transmit interrupts are on */
 923
 924	        /* Check this ! */
 925	        local_irq_save(flags);
 926		if(!(custom.intenar & IF_TBE)) {
 927		    custom.intena = IF_SETCLR | IF_TBE;
 928		    mb();
 929		    /* set a pending Tx Interrupt, transmitter should restart now */
 930		    custom.intreq = IF_SETCLR | IF_TBE;
 931		    mb();
 932		}
 933		local_irq_restore(flags);
 934
 935		info->IER |= UART_IER_THRI;
 936	}
 937}
 938
 939/*
 940 * ------------------------------------------------------------
 941 * rs_throttle()
 942 * 
 943 * This routine is called by the upper-layer tty layer to signal that
 944 * incoming characters should be throttled.
 945 * ------------------------------------------------------------
 946 */
 947static void rs_throttle(struct tty_struct * tty)
 948{
 949	struct serial_state *info = tty->driver_data;
 950	unsigned long flags;
 951#ifdef SERIAL_DEBUG_THROTTLE
 952	printk("throttle %s ....\n", tty_name(tty));
 953#endif
 954
 955	if (serial_paranoia_check(info, tty->name, "rs_throttle"))
 956		return;
 957
 958	if (I_IXOFF(tty))
 959		rs_send_xchar(tty, STOP_CHAR(tty));
 960
 961	if (C_CRTSCTS(tty))
 962		info->MCR &= ~SER_RTS;
 963
 964	local_irq_save(flags);
 965	rtsdtr_ctrl(info->MCR);
 966	local_irq_restore(flags);
 967}
 968
 969static void rs_unthrottle(struct tty_struct * tty)
 970{
 971	struct serial_state *info = tty->driver_data;
 972	unsigned long flags;
 973#ifdef SERIAL_DEBUG_THROTTLE
 974	printk("unthrottle %s ....\n", tty_name(tty));
 975#endif
 976
 977	if (serial_paranoia_check(info, tty->name, "rs_unthrottle"))
 978		return;
 979
 980	if (I_IXOFF(tty)) {
 981		if (info->x_char)
 982			info->x_char = 0;
 983		else
 984			rs_send_xchar(tty, START_CHAR(tty));
 985	}
 986	if (C_CRTSCTS(tty))
 987		info->MCR |= SER_RTS;
 988	local_irq_save(flags);
 989	rtsdtr_ctrl(info->MCR);
 990	local_irq_restore(flags);
 991}
 992
 993/*
 994 * ------------------------------------------------------------
 995 * rs_ioctl() and friends
 996 * ------------------------------------------------------------
 997 */
 998
 999static int get_serial_info(struct tty_struct *tty, struct serial_struct *ss)
1000{
1001	struct serial_state *state = tty->driver_data;
 
1002
1003	tty_lock(tty);
 
 
 
 
 
1004	ss->line = tty->index;
1005	ss->port = state->port;
1006	ss->flags = state->tport.flags;
1007	ss->xmit_fifo_size = state->xmit_fifo_size;
1008	ss->baud_base = state->baud_base;
1009	ss->close_delay = state->tport.close_delay;
1010	ss->closing_wait = state->tport.closing_wait;
1011	ss->custom_divisor = state->custom_divisor;
1012	tty_unlock(tty);
1013	return 0;
1014}
1015
1016static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss)
1017{
1018	struct serial_state *state = tty->driver_data;
1019	struct tty_port *port = &state->tport;
1020	bool change_spd;
1021	int 			retval = 0;
 
1022
1023	tty_lock(tty);
1024	change_spd = ((ss->flags ^ port->flags) & ASYNC_SPD_MASK) ||
1025		ss->custom_divisor != state->custom_divisor;
1026	if (ss->irq || ss->port != state->port ||
1027			ss->xmit_fifo_size != state->xmit_fifo_size) {
1028		tty_unlock(tty);
1029		return -EINVAL;
1030	}
1031  
 
 
 
 
 
1032	if (!serial_isroot()) {
1033		if ((ss->baud_base != state->baud_base) ||
1034		    (ss->close_delay != port->close_delay) ||
 
1035		    (ss->xmit_fifo_size != state->xmit_fifo_size) ||
1036		    ((ss->flags & ~ASYNC_USR_MASK) !=
1037		     (port->flags & ~ASYNC_USR_MASK))) {
1038			tty_unlock(tty);
1039			return -EPERM;
1040		}
1041		port->flags = ((port->flags & ~ASYNC_USR_MASK) |
1042			       (ss->flags & ASYNC_USR_MASK));
1043		state->custom_divisor = ss->custom_divisor;
1044		goto check_and_exit;
1045	}
1046
1047	if (ss->baud_base < 9600) {
1048		tty_unlock(tty);
1049		return -EINVAL;
1050	}
1051
1052	/*
1053	 * OK, past this point, all the error checking has been done.
1054	 * At this point, we start making changes.....
1055	 */
1056
1057	state->baud_base = ss->baud_base;
1058	port->flags = ((port->flags & ~ASYNC_FLAGS) |
1059			(ss->flags & ASYNC_FLAGS));
1060	state->custom_divisor = ss->custom_divisor;
1061	port->close_delay = ss->close_delay * HZ/100;
1062	port->closing_wait = ss->closing_wait * HZ/100;
1063	port->low_latency = (port->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
1064
1065check_and_exit:
1066	if (tty_port_initialized(port)) {
1067		if (change_spd) {
1068			/* warn about deprecation unless clearing */
1069			if (ss->flags & ASYNC_SPD_MASK)
1070				dev_warn_ratelimited(tty->dev, "use of SPD flags is deprecated\n");
1071			change_speed(tty, state, NULL);
1072		}
1073	} else
1074		retval = startup(tty, state);
1075	tty_unlock(tty);
1076	return retval;
1077}
1078
1079/*
1080 * get_lsr_info - get line status register info
1081 *
1082 * Purpose: Let user call ioctl() to get info when the UART physically
1083 * 	    is emptied.  On bus types like RS485, the transmitter must
1084 * 	    release the bus after transmitting. This must be done when
1085 * 	    the transmit shift register is empty, not be done when the
1086 * 	    transmit holding register is empty.  This functionality
1087 * 	    allows an RS485 driver to be written in user space. 
1088 */
1089static int get_lsr_info(struct serial_state *info, unsigned int __user *value)
1090{
1091	unsigned char status;
1092	unsigned int result;
1093	unsigned long flags;
1094
1095	local_irq_save(flags);
1096	status = custom.serdatr;
1097	mb();
1098	local_irq_restore(flags);
1099	result = ((status & SDR_TSRE) ? TIOCSER_TEMT : 0);
1100	if (copy_to_user(value, &result, sizeof(int)))
1101		return -EFAULT;
1102	return 0;
1103}
1104
1105
1106static int rs_tiocmget(struct tty_struct *tty)
1107{
1108	struct serial_state *info = tty->driver_data;
1109	unsigned char control, status;
1110	unsigned long flags;
1111
1112	if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
1113		return -ENODEV;
1114	if (tty_io_error(tty))
1115		return -EIO;
1116
1117	control = info->MCR;
1118	local_irq_save(flags);
1119	status = ciab.pra;
1120	local_irq_restore(flags);
1121	return    ((control & SER_RTS) ? TIOCM_RTS : 0)
1122		| ((control & SER_DTR) ? TIOCM_DTR : 0)
1123		| (!(status  & SER_DCD) ? TIOCM_CAR : 0)
1124		| (!(status  & SER_DSR) ? TIOCM_DSR : 0)
1125		| (!(status  & SER_CTS) ? TIOCM_CTS : 0);
1126}
1127
1128static int rs_tiocmset(struct tty_struct *tty, unsigned int set,
1129						unsigned int clear)
1130{
1131	struct serial_state *info = tty->driver_data;
1132	unsigned long flags;
1133
1134	if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
1135		return -ENODEV;
1136	if (tty_io_error(tty))
1137		return -EIO;
1138
1139	local_irq_save(flags);
1140	if (set & TIOCM_RTS)
1141		info->MCR |= SER_RTS;
1142	if (set & TIOCM_DTR)
1143		info->MCR |= SER_DTR;
1144	if (clear & TIOCM_RTS)
1145		info->MCR &= ~SER_RTS;
1146	if (clear & TIOCM_DTR)
1147		info->MCR &= ~SER_DTR;
1148	rtsdtr_ctrl(info->MCR);
1149	local_irq_restore(flags);
1150	return 0;
1151}
1152
1153/*
1154 * rs_break() --- routine which turns the break handling on or off
1155 */
1156static int rs_break(struct tty_struct *tty, int break_state)
1157{
1158	struct serial_state *info = tty->driver_data;
1159	unsigned long flags;
1160
1161	if (serial_paranoia_check(info, tty->name, "rs_break"))
1162		return -EINVAL;
1163
1164	local_irq_save(flags);
1165	if (break_state == -1)
1166	  custom.adkcon = AC_SETCLR | AC_UARTBRK;
1167	else
1168	  custom.adkcon = AC_UARTBRK;
1169	mb();
1170	local_irq_restore(flags);
1171	return 0;
1172}
1173
1174/*
1175 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1176 * Return: write counters to the user passed counter struct
1177 * NB: both 1->0 and 0->1 transitions are counted except for
1178 *     RI where only 0->1 is counted.
1179 */
1180static int rs_get_icount(struct tty_struct *tty,
1181				struct serial_icounter_struct *icount)
1182{
1183	struct serial_state *info = tty->driver_data;
1184	struct async_icount cnow;
1185	unsigned long flags;
1186
1187	local_irq_save(flags);
1188	cnow = info->icount;
1189	local_irq_restore(flags);
1190	icount->cts = cnow.cts;
1191	icount->dsr = cnow.dsr;
1192	icount->rng = cnow.rng;
1193	icount->dcd = cnow.dcd;
1194	icount->rx = cnow.rx;
1195	icount->tx = cnow.tx;
1196	icount->frame = cnow.frame;
1197	icount->overrun = cnow.overrun;
1198	icount->parity = cnow.parity;
1199	icount->brk = cnow.brk;
1200	icount->buf_overrun = cnow.buf_overrun;
1201
1202	return 0;
1203}
1204
1205static int rs_ioctl(struct tty_struct *tty,
1206		    unsigned int cmd, unsigned long arg)
1207{
1208	struct serial_state *info = tty->driver_data;
1209	struct async_icount cprev, cnow;	/* kernel counter temps */
1210	void __user *argp = (void __user *)arg;
1211	unsigned long flags;
1212	DEFINE_WAIT(wait);
1213	int ret;
1214
1215	if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
1216		return -ENODEV;
1217
1218	if ((cmd != TIOCSERCONFIG) &&
1219	    (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
1220		if (tty_io_error(tty))
1221		    return -EIO;
1222	}
1223
1224	switch (cmd) {
1225		case TIOCSERCONFIG:
1226			return 0;
1227
1228		case TIOCSERGETLSR: /* Get line status register */
1229			return get_lsr_info(info, argp);
1230
1231		/*
1232		 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1233		 * - mask passed in arg for lines of interest
1234 		 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1235		 * Caller should use TIOCGICOUNT to see which one it was
1236		 */
1237		case TIOCMIWAIT:
1238			local_irq_save(flags);
1239			/* note the counters on entry */
1240			cprev = info->icount;
1241			local_irq_restore(flags);
1242			while (1) {
1243				prepare_to_wait(&info->tport.delta_msr_wait,
1244						&wait, TASK_INTERRUPTIBLE);
1245				local_irq_save(flags);
1246				cnow = info->icount; /* atomic copy */
1247				local_irq_restore(flags);
1248				if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr && 
1249				    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts) {
1250					ret = -EIO; /* no change => error */
1251					break;
1252				}
1253				if ( ((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
1254				     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
1255				     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
1256				     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
1257					ret = 0;
1258					break;
1259				}
1260				schedule();
1261				/* see if a signal did it */
1262				if (signal_pending(current)) {
1263					ret = -ERESTARTSYS;
1264					break;
1265				}
1266				cprev = cnow;
1267			}
1268			finish_wait(&info->tport.delta_msr_wait, &wait);
1269			return ret;
1270
1271		default:
1272			return -ENOIOCTLCMD;
1273		}
1274	return 0;
1275}
1276
1277static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
1278{
1279	struct serial_state *info = tty->driver_data;
1280	unsigned long flags;
1281	unsigned int cflag = tty->termios.c_cflag;
1282
1283	change_speed(tty, info, old_termios);
1284
1285	/* Handle transition to B0 status */
1286	if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD)) {
1287		info->MCR &= ~(SER_DTR|SER_RTS);
1288		local_irq_save(flags);
1289		rtsdtr_ctrl(info->MCR);
1290		local_irq_restore(flags);
1291	}
1292
1293	/* Handle transition away from B0 status */
1294	if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
1295		info->MCR |= SER_DTR;
1296		if (!C_CRTSCTS(tty) || !tty_throttled(tty))
1297			info->MCR |= SER_RTS;
1298		local_irq_save(flags);
1299		rtsdtr_ctrl(info->MCR);
1300		local_irq_restore(flags);
1301	}
1302
1303	/* Handle turning off CRTSCTS */
1304	if ((old_termios->c_cflag & CRTSCTS) && !C_CRTSCTS(tty)) {
1305		tty->hw_stopped = 0;
1306		rs_start(tty);
1307	}
1308
1309#if 0
1310	/*
1311	 * No need to wake up processes in open wait, since they
1312	 * sample the CLOCAL flag once, and don't recheck it.
1313	 * XXX  It's not clear whether the current behavior is correct
1314	 * or not.  Hence, this may change.....
1315	 */
1316	if (!(old_termios->c_cflag & CLOCAL) && C_CLOCAL(tty))
1317		wake_up_interruptible(&info->open_wait);
1318#endif
1319}
1320
1321/*
1322 * ------------------------------------------------------------
1323 * rs_close()
1324 * 
1325 * This routine is called when the serial port gets closed.  First, we
1326 * wait for the last remaining data to be sent.  Then, we unlink its
1327 * async structure from the interrupt chain if necessary, and we free
1328 * that IRQ if nothing is left in the chain.
1329 * ------------------------------------------------------------
1330 */
1331static void rs_close(struct tty_struct *tty, struct file * filp)
1332{
1333	struct serial_state *state = tty->driver_data;
1334	struct tty_port *port = &state->tport;
1335
1336	if (serial_paranoia_check(state, tty->name, "rs_close"))
1337		return;
1338
1339	if (tty_port_close_start(port, tty, filp) == 0)
1340		return;
1341
1342	/*
1343	 * At this point we stop accepting input.  To do this, we
1344	 * disable the receive line status interrupts, and tell the
1345	 * interrupt driver to stop checking the data ready bit in the
1346	 * line status register.
1347	 */
1348	state->read_status_mask &= ~UART_LSR_DR;
1349	if (tty_port_initialized(port)) {
1350	        /* disable receive interrupts */
1351	        custom.intena = IF_RBF;
1352		mb();
1353		/* clear any pending receive interrupt */
1354		custom.intreq = IF_RBF;
1355		mb();
1356
1357		/*
1358		 * Before we drop DTR, make sure the UART transmitter
1359		 * has completely drained; this is especially
1360		 * important if there is a transmit FIFO!
1361		 */
1362		rs_wait_until_sent(tty, state->timeout);
1363	}
1364	shutdown(tty, state);
1365	rs_flush_buffer(tty);
1366		
1367	tty_ldisc_flush(tty);
1368	port->tty = NULL;
1369
1370	tty_port_close_end(port, tty);
1371}
1372
1373/*
1374 * rs_wait_until_sent() --- wait until the transmitter is empty
1375 */
1376static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
1377{
1378	struct serial_state *info = tty->driver_data;
1379	unsigned long orig_jiffies, char_time;
1380	int lsr;
1381
1382	if (serial_paranoia_check(info, tty->name, "rs_wait_until_sent"))
1383		return;
1384
1385	if (info->xmit_fifo_size == 0)
1386		return; /* Just in case.... */
1387
1388	orig_jiffies = jiffies;
1389
1390	/*
1391	 * Set the check interval to be 1/5 of the estimated time to
1392	 * send a single character, and make it at least 1.  The check
1393	 * interval should also be less than the timeout.
1394	 * 
1395	 * Note: we have to use pretty tight timings here to satisfy
1396	 * the NIST-PCTS.
1397	 */
1398	char_time = (info->timeout - HZ/50) / info->xmit_fifo_size;
1399	char_time = char_time / 5;
1400	if (char_time == 0)
1401		char_time = 1;
1402	if (timeout)
1403	  char_time = min_t(unsigned long, char_time, timeout);
1404	/*
1405	 * If the transmitter hasn't cleared in twice the approximate
1406	 * amount of time to send the entire FIFO, it probably won't
1407	 * ever clear.  This assumes the UART isn't doing flow
1408	 * control, which is currently the case.  Hence, if it ever
1409	 * takes longer than info->timeout, this is probably due to a
1410	 * UART bug of some kind.  So, we clamp the timeout parameter at
1411	 * 2*info->timeout.
1412	 */
1413	if (!timeout || timeout > 2*info->timeout)
1414		timeout = 2*info->timeout;
1415#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1416	printk("In rs_wait_until_sent(%d) check=%lu...", timeout, char_time);
1417	printk("jiff=%lu...", jiffies);
1418#endif
1419	while(!((lsr = custom.serdatr) & SDR_TSRE)) {
1420#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1421		printk("serdatr = %d (jiff=%lu)...", lsr, jiffies);
1422#endif
1423		msleep_interruptible(jiffies_to_msecs(char_time));
1424		if (signal_pending(current))
1425			break;
1426		if (timeout && time_after(jiffies, orig_jiffies + timeout))
1427			break;
1428	}
1429	__set_current_state(TASK_RUNNING);
1430
1431#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
1432	printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
1433#endif
1434}
1435
1436/*
1437 * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
1438 */
1439static void rs_hangup(struct tty_struct *tty)
1440{
1441	struct serial_state *info = tty->driver_data;
1442
1443	if (serial_paranoia_check(info, tty->name, "rs_hangup"))
1444		return;
1445
1446	rs_flush_buffer(tty);
1447	shutdown(tty, info);
1448	info->tport.count = 0;
1449	tty_port_set_active(&info->tport, 0);
1450	info->tport.tty = NULL;
1451	wake_up_interruptible(&info->tport.open_wait);
1452}
1453
1454/*
1455 * This routine is called whenever a serial port is opened.  It
1456 * enables interrupts for a serial port, linking in its async structure into
1457 * the IRQ chain.   It also performs the serial-specific
1458 * initialization for the tty structure.
1459 */
1460static int rs_open(struct tty_struct *tty, struct file * filp)
1461{
1462	struct serial_state *info = rs_table + tty->index;
1463	struct tty_port *port = &info->tport;
1464	int retval;
1465
1466	port->count++;
1467	port->tty = tty;
1468	tty->driver_data = info;
1469	tty->port = port;
1470	if (serial_paranoia_check(info, tty->name, "rs_open"))
1471		return -ENODEV;
1472
1473	port->low_latency = (port->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
1474
1475	retval = startup(tty, info);
1476	if (retval) {
1477		return retval;
1478	}
1479
1480	return tty_port_block_til_ready(port, tty, filp);
1481}
1482
1483/*
1484 * /proc fs routines....
1485 */
1486
1487static inline void line_info(struct seq_file *m, int line,
1488		struct serial_state *state)
1489{
1490	char	stat_buf[30], control, status;
1491	unsigned long flags;
1492
1493	seq_printf(m, "%d: uart:amiga_builtin", line);
1494
1495	local_irq_save(flags);
1496	status = ciab.pra;
1497	control = tty_port_initialized(&state->tport) ? state->MCR : status;
1498	local_irq_restore(flags);
1499
1500	stat_buf[0] = 0;
1501	stat_buf[1] = 0;
1502	if(!(control & SER_RTS))
1503		strcat(stat_buf, "|RTS");
1504	if(!(status & SER_CTS))
1505		strcat(stat_buf, "|CTS");
1506	if(!(control & SER_DTR))
1507		strcat(stat_buf, "|DTR");
1508	if(!(status & SER_DSR))
1509		strcat(stat_buf, "|DSR");
1510	if(!(status & SER_DCD))
1511		strcat(stat_buf, "|CD");
1512
1513	if (state->quot)
1514		seq_printf(m, " baud:%d", state->baud_base / state->quot);
1515
1516	seq_printf(m, " tx:%d rx:%d", state->icount.tx, state->icount.rx);
1517
1518	if (state->icount.frame)
1519		seq_printf(m, " fe:%d", state->icount.frame);
1520
1521	if (state->icount.parity)
1522		seq_printf(m, " pe:%d", state->icount.parity);
1523
1524	if (state->icount.brk)
1525		seq_printf(m, " brk:%d", state->icount.brk);
1526
1527	if (state->icount.overrun)
1528		seq_printf(m, " oe:%d", state->icount.overrun);
1529
1530	/*
1531	 * Last thing is the RS-232 status lines
1532	 */
1533	seq_printf(m, " %s\n", stat_buf+1);
1534}
1535
1536static int rs_proc_show(struct seq_file *m, void *v)
1537{
1538	seq_printf(m, "serinfo:1.0 driver:%s\n", serial_version);
1539	line_info(m, 0, &rs_table[0]);
1540	return 0;
1541}
1542
1543/*
1544 * ---------------------------------------------------------------------
1545 * rs_init() and friends
1546 *
1547 * rs_init() is called at boot-time to initialize the serial driver.
1548 * ---------------------------------------------------------------------
1549 */
1550
1551/*
1552 * This routine prints out the appropriate serial driver version
1553 * number, and identifies which options were configured into this
1554 * driver.
1555 */
1556static void show_serial_version(void)
1557{
1558 	printk(KERN_INFO "%s version %s\n", serial_name, serial_version);
1559}
1560
1561
1562static const struct tty_operations serial_ops = {
1563	.open = rs_open,
1564	.close = rs_close,
1565	.write = rs_write,
1566	.put_char = rs_put_char,
1567	.flush_chars = rs_flush_chars,
1568	.write_room = rs_write_room,
1569	.chars_in_buffer = rs_chars_in_buffer,
1570	.flush_buffer = rs_flush_buffer,
1571	.ioctl = rs_ioctl,
1572	.throttle = rs_throttle,
1573	.unthrottle = rs_unthrottle,
1574	.set_termios = rs_set_termios,
1575	.stop = rs_stop,
1576	.start = rs_start,
1577	.hangup = rs_hangup,
1578	.break_ctl = rs_break,
1579	.send_xchar = rs_send_xchar,
1580	.wait_until_sent = rs_wait_until_sent,
1581	.tiocmget = rs_tiocmget,
1582	.tiocmset = rs_tiocmset,
1583	.get_icount = rs_get_icount,
1584	.set_serial = set_serial_info,
1585	.get_serial = get_serial_info,
1586	.proc_show = rs_proc_show,
1587};
1588
1589static int amiga_carrier_raised(struct tty_port *port)
1590{
1591	return !(ciab.pra & SER_DCD);
1592}
1593
1594static void amiga_dtr_rts(struct tty_port *port, int raise)
1595{
1596	struct serial_state *info = container_of(port, struct serial_state,
1597			tport);
1598	unsigned long flags;
1599
1600	if (raise)
1601		info->MCR |= SER_DTR|SER_RTS;
1602	else
1603		info->MCR &= ~(SER_DTR|SER_RTS);
1604
1605	local_irq_save(flags);
1606	rtsdtr_ctrl(info->MCR);
1607	local_irq_restore(flags);
1608}
1609
1610static const struct tty_port_operations amiga_port_ops = {
1611	.carrier_raised = amiga_carrier_raised,
1612	.dtr_rts = amiga_dtr_rts,
1613};
1614
1615/*
1616 * The serial driver boot-time initialization code!
1617 */
1618static int __init amiga_serial_probe(struct platform_device *pdev)
1619{
1620	unsigned long flags;
1621	struct serial_state * state;
1622	int error;
1623
1624	serial_driver = alloc_tty_driver(NR_PORTS);
1625	if (!serial_driver)
1626		return -ENOMEM;
1627
1628	show_serial_version();
1629
1630	/* Initialize the tty_driver structure */
1631
1632	serial_driver->driver_name = "amiserial";
1633	serial_driver->name = "ttyS";
1634	serial_driver->major = TTY_MAJOR;
1635	serial_driver->minor_start = 64;
1636	serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
1637	serial_driver->subtype = SERIAL_TYPE_NORMAL;
1638	serial_driver->init_termios = tty_std_termios;
1639	serial_driver->init_termios.c_cflag =
1640		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1641	serial_driver->flags = TTY_DRIVER_REAL_RAW;
1642	tty_set_operations(serial_driver, &serial_ops);
1643
1644	state = rs_table;
1645	state->port = (int)&custom.serdatr; /* Just to give it a value */
1646	state->custom_divisor = 0;
1647	state->icount.cts = state->icount.dsr = 
1648	  state->icount.rng = state->icount.dcd = 0;
1649	state->icount.rx = state->icount.tx = 0;
1650	state->icount.frame = state->icount.parity = 0;
1651	state->icount.overrun = state->icount.brk = 0;
1652	tty_port_init(&state->tport);
1653	state->tport.ops = &amiga_port_ops;
1654	tty_port_link_device(&state->tport, serial_driver, 0);
1655
1656	error = tty_register_driver(serial_driver);
1657	if (error)
1658		goto fail_put_tty_driver;
1659
1660	printk(KERN_INFO "ttyS0 is the amiga builtin serial port\n");
1661
1662	/* Hardware set up */
1663
1664	state->baud_base = amiga_colorclock;
1665	state->xmit_fifo_size = 1;
1666
1667	/* set ISRs, and then disable the rx interrupts */
1668	error = request_irq(IRQ_AMIGA_TBE, ser_tx_int, 0, "serial TX", state);
1669	if (error)
1670		goto fail_unregister;
1671
1672	error = request_irq(IRQ_AMIGA_RBF, ser_rx_int, 0,
1673			    "serial RX", state);
1674	if (error)
1675		goto fail_free_irq;
1676
1677	local_irq_save(flags);
1678
1679	/* turn off Rx and Tx interrupts */
1680	custom.intena = IF_RBF | IF_TBE;
1681	mb();
1682
1683	/* clear any pending interrupt */
1684	custom.intreq = IF_RBF | IF_TBE;
1685	mb();
1686
1687	local_irq_restore(flags);
1688
1689	/*
1690	 * set the appropriate directions for the modem control flags,
1691	 * and clear RTS and DTR
1692	 */
1693	ciab.ddra |= (SER_DTR | SER_RTS);   /* outputs */
1694	ciab.ddra &= ~(SER_DCD | SER_CTS | SER_DSR);  /* inputs */
1695
1696	platform_set_drvdata(pdev, state);
1697
1698	return 0;
1699
1700fail_free_irq:
1701	free_irq(IRQ_AMIGA_TBE, state);
1702fail_unregister:
1703	tty_unregister_driver(serial_driver);
1704fail_put_tty_driver:
1705	tty_port_destroy(&state->tport);
1706	put_tty_driver(serial_driver);
1707	return error;
1708}
1709
1710static int __exit amiga_serial_remove(struct platform_device *pdev)
1711{
1712	int error;
1713	struct serial_state *state = platform_get_drvdata(pdev);
1714
1715	/* printk("Unloading %s: version %s\n", serial_name, serial_version); */
1716	error = tty_unregister_driver(serial_driver);
1717	if (error)
1718		printk("SERIAL: failed to unregister serial driver (%d)\n",
1719		       error);
1720	put_tty_driver(serial_driver);
1721	tty_port_destroy(&state->tport);
1722
1723	free_irq(IRQ_AMIGA_TBE, state);
1724	free_irq(IRQ_AMIGA_RBF, state);
1725
1726	return error;
1727}
1728
1729static struct platform_driver amiga_serial_driver = {
1730	.remove = __exit_p(amiga_serial_remove),
1731	.driver   = {
1732		.name	= "amiga-serial",
1733	},
1734};
1735
1736module_platform_driver_probe(amiga_serial_driver, amiga_serial_probe);
1737
1738
1739#if defined(CONFIG_SERIAL_CONSOLE) && !defined(MODULE)
1740
1741/*
1742 * ------------------------------------------------------------
1743 * Serial console driver
1744 * ------------------------------------------------------------
1745 */
1746
1747static void amiga_serial_putc(char c)
1748{
1749	custom.serdat = (unsigned char)c | 0x100;
1750	while (!(custom.serdatr & 0x2000))
1751		barrier();
1752}
1753
1754/*
1755 *	Print a string to the serial port trying not to disturb
1756 *	any possible real use of the port...
1757 *
1758 *	The console must be locked when we get here.
1759 */
1760static void serial_console_write(struct console *co, const char *s,
1761				unsigned count)
1762{
1763	unsigned short intena = custom.intenar;
1764
1765	custom.intena = IF_TBE;
1766
1767	while (count--) {
1768		if (*s == '\n')
1769			amiga_serial_putc('\r');
1770		amiga_serial_putc(*s++);
1771	}
1772
1773	custom.intena = IF_SETCLR | (intena & IF_TBE);
1774}
1775
1776static struct tty_driver *serial_console_device(struct console *c, int *index)
1777{
1778	*index = 0;
1779	return serial_driver;
1780}
1781
1782static struct console sercons = {
1783	.name =		"ttyS",
1784	.write =	serial_console_write,
1785	.device =	serial_console_device,
1786	.flags =	CON_PRINTBUFFER,
1787	.index =	-1,
1788};
1789
1790/*
1791 *	Register console.
1792 */
1793static int __init amiserial_console_init(void)
1794{
1795	if (!MACH_IS_AMIGA)
1796		return -ENODEV;
1797
1798	register_console(&sercons);
1799	return 0;
1800}
1801console_initcall(amiserial_console_init);
1802
1803#endif /* CONFIG_SERIAL_CONSOLE && !MODULE */
1804
1805MODULE_LICENSE("GPL");
1806MODULE_ALIAS("platform:amiga-serial");