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   1/* 68328serial.c: Serial port driver for 68328 microcontroller
   2 *
   3 * Copyright (C) 1995       David S. Miller    <davem@caip.rutgers.edu>
   4 * Copyright (C) 1998       Kenneth Albanowski <kjahds@kjahds.com>
   5 * Copyright (C) 1998, 1999 D. Jeff Dionne     <jeff@uclinux.org>
   6 * Copyright (C) 1999       Vladimir Gurevich  <vgurevic@cisco.com>
   7 * Copyright (C) 2002-2003  David McCullough   <davidm@snapgear.com>
   8 * Copyright (C) 2002       Greg Ungerer       <gerg@snapgear.com>
   9 *
  10 * VZ Support/Fixes             Evan Stawnyczy <e@lineo.ca>
  11 * Multiple UART support        Daniel Potts <danielp@cse.unsw.edu.au>
  12 * Power management support     Daniel Potts <danielp@cse.unsw.edu.au>
  13 * VZ Second Serial Port enable Phil Wilshire
  14 * 2.4/2.5 port                 David McCullough
  15 */
  16
  17#include <asm/dbg.h>
  18#include <linux/module.h>
  19#include <linux/errno.h>
  20#include <linux/serial.h>
  21#include <linux/signal.h>
  22#include <linux/sched.h>
  23#include <linux/timer.h>
  24#include <linux/interrupt.h>
  25#include <linux/tty.h>
  26#include <linux/tty_flip.h>
  27#include <linux/major.h>
  28#include <linux/string.h>
  29#include <linux/fcntl.h>
  30#include <linux/mm.h>
  31#include <linux/kernel.h>
  32#include <linux/console.h>
  33#include <linux/reboot.h>
  34#include <linux/keyboard.h>
  35#include <linux/init.h>
  36#include <linux/pm.h>
  37#include <linux/bitops.h>
  38#include <linux/delay.h>
  39#include <linux/gfp.h>
  40
  41#include <asm/io.h>
  42#include <asm/irq.h>
  43#include <asm/delay.h>
  44#include <asm/uaccess.h>
  45
  46/* (es) */
  47/* note: perhaps we can murge these files, so that you can just
  48 * 	 define 1 of them, and they can sort that out for themselves
  49 */
  50#if defined(CONFIG_M68EZ328)
  51#include <asm/MC68EZ328.h>
  52#else
  53#if defined(CONFIG_M68VZ328)
  54#include <asm/MC68VZ328.h>
  55#else
  56#include <asm/MC68328.h>
  57#endif /* CONFIG_M68VZ328 */
  58#endif /* CONFIG_M68EZ328 */
  59
  60/* Turn off usage of real serial interrupt code, to "support" Copilot */
  61#ifdef CONFIG_XCOPILOT_BUGS
  62#undef USE_INTS
  63#else
  64#define USE_INTS
  65#endif
  66
  67/*
  68 * I believe this is the optimal setting that reduces the number of interrupts.
  69 * At high speeds the output might become a little "bursted" (use USTCNT_TXHE
  70 * if that bothers you), but in most cases it will not, since we try to
  71 * transmit characters every time rs_interrupt is called. Thus, quite often
  72 * you'll see that a receive interrupt occures before the transmit one.
  73 *                                  -- Vladimir Gurevich
  74 */
  75#define USTCNT_TX_INTR_MASK (USTCNT_TXEE)
  76
  77/*
  78 * 68328 and 68EZ328 UARTS are a little bit different. EZ328 has special
  79 * "Old data interrupt" which occures whenever the data stay in the FIFO
  80 * longer than 30 bits time. This allows us to use FIFO without compromising
  81 * latency. '328 does not have this feature and without the real  328-based
  82 * board I would assume that RXRE is the safest setting.
  83 *
  84 * For EZ328 I use RXHE (Half empty) interrupt to reduce the number of
  85 * interrupts. RXFE (receive queue full) causes the system to lose data
  86 * at least at 115200 baud
  87 *
  88 * If your board is busy doing other stuff, you might consider to use
  89 * RXRE (data ready intrrupt) instead.
  90 *
  91 * The other option is to make these INTR masks run-time configurable, so
  92 * that people can dynamically adapt them according to the current usage.
  93 *                                  -- Vladimir Gurevich
  94 */
  95
  96/* (es) */
  97#if defined(CONFIG_M68EZ328) || defined(CONFIG_M68VZ328)
  98#define USTCNT_RX_INTR_MASK (USTCNT_RXHE | USTCNT_ODEN)
  99#elif defined(CONFIG_M68328)
 100#define USTCNT_RX_INTR_MASK (USTCNT_RXRE)
 101#else
 102#error Please, define the Rx interrupt events for your CPU
 103#endif
 104/* (/es) */
 105
 106/*
 107 * This is our internal structure for each serial port's state.
 108 */
 109struct m68k_serial {
 110	struct tty_port		tport;
 111	char			is_cons;	/* Is this our console. */
 112	int			magic;
 113	int			baud_base;
 114	int			port;
 115	int			irq;
 116	int			type;		/* UART type */
 117	int			custom_divisor;
 118	int			x_char;		/* xon/xoff character */
 119	int			line;
 120	unsigned char		*xmit_buf;
 121	int			xmit_head;
 122	int			xmit_tail;
 123	int			xmit_cnt;
 124};
 125
 126#define SERIAL_MAGIC 0x5301
 127
 128/*
 129 * Define the number of ports supported and their irqs.
 130 */
 131#define NR_PORTS 1
 132
 133static struct m68k_serial m68k_soft[NR_PORTS];
 134
 135static unsigned int uart_irqs[NR_PORTS] = { UART_IRQ_NUM };
 136
 137/* multiple ports are contiguous in memory */
 138m68328_uart *uart_addr = (m68328_uart *)USTCNT_ADDR;
 139
 140struct tty_driver *serial_driver;
 141
 142static void change_speed(struct m68k_serial *info, struct tty_struct *tty);
 143
 144/*
 145 *	Setup for console. Argument comes from the boot command line.
 146 */
 147
 148/* note: this is messy, but it works, again, perhaps defined somewhere else?*/
 149#ifdef CONFIG_M68VZ328
 150#define CONSOLE_BAUD_RATE	19200
 151#define DEFAULT_CBAUD		B19200
 152#endif
 153
 154
 155#ifndef CONSOLE_BAUD_RATE
 156#define	CONSOLE_BAUD_RATE	9600
 157#define	DEFAULT_CBAUD		B9600
 158#endif
 159
 160
 161static int m68328_console_initted = 0;
 162static int m68328_console_baud    = CONSOLE_BAUD_RATE;
 163static int m68328_console_cbaud   = DEFAULT_CBAUD;
 164
 165
 166static inline int serial_paranoia_check(struct m68k_serial *info,
 167					char *name, const char *routine)
 168{
 169#ifdef SERIAL_PARANOIA_CHECK
 170	static const char *badmagic =
 171		"Warning: bad magic number for serial struct %s in %s\n";
 172	static const char *badinfo =
 173		"Warning: null m68k_serial for %s in %s\n";
 174
 175	if (!info) {
 176		printk(badinfo, name, routine);
 177		return 1;
 178	}
 179	if (info->magic != SERIAL_MAGIC) {
 180		printk(badmagic, name, routine);
 181		return 1;
 182	}
 183#endif
 184	return 0;
 185}
 186
 187/*
 188 * This is used to figure out the divisor speeds and the timeouts
 189 */
 190static int baud_table[] = {
 191	0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
 192	9600, 19200, 38400, 57600, 115200, 0 };
 193
 194/* Utility routines */
 195static inline int get_baud(struct m68k_serial *ss)
 196{
 197	unsigned long result = 115200;
 198	unsigned short int baud = uart_addr[ss->line].ubaud;
 199	if (GET_FIELD(baud, UBAUD_PRESCALER) == 0x38) result = 38400;
 200	result >>= GET_FIELD(baud, UBAUD_DIVIDE);
 201
 202	return result;
 203}
 204
 205/*
 206 * ------------------------------------------------------------
 207 * rs_stop() and rs_start()
 208 *
 209 * This routines are called before setting or resetting tty->stopped.
 210 * They enable or disable transmitter interrupts, as necessary.
 211 * ------------------------------------------------------------
 212 */
 213static void rs_stop(struct tty_struct *tty)
 214{
 215	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
 216	m68328_uart *uart = &uart_addr[info->line];
 217	unsigned long flags;
 218
 219	if (serial_paranoia_check(info, tty->name, "rs_stop"))
 220		return;
 221	
 222	local_irq_save(flags);
 223	uart->ustcnt &= ~USTCNT_TXEN;
 224	local_irq_restore(flags);
 225}
 226
 227static int rs_put_char(char ch)
 228{
 229	unsigned long flags;
 230	int loops = 0;
 231
 232        local_irq_save(flags);
 233
 234	while (!(UTX & UTX_TX_AVAIL) && (loops < 1000)) {
 235        	loops++;
 236        	udelay(5);
 237        }
 238
 239	UTX_TXDATA = ch;
 240        udelay(5);
 241        local_irq_restore(flags);
 242        return 1;
 243}
 244
 245static void rs_start(struct tty_struct *tty)
 246{
 247	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
 248	m68328_uart *uart = &uart_addr[info->line];
 249	unsigned long flags;
 250	
 251	if (serial_paranoia_check(info, tty->name, "rs_start"))
 252		return;
 253	
 254	local_irq_save(flags);
 255	if (info->xmit_cnt && info->xmit_buf && !(uart->ustcnt & USTCNT_TXEN)) {
 256#ifdef USE_INTS
 257		uart->ustcnt |= USTCNT_TXEN | USTCNT_TX_INTR_MASK;
 258#else
 259		uart->ustcnt |= USTCNT_TXEN;
 260#endif
 261	}
 262	local_irq_restore(flags);
 263}
 264
 265static void receive_chars(struct m68k_serial *info, struct tty_struct *tty,
 266		unsigned short rx)
 267{
 268	m68328_uart *uart = &uart_addr[info->line];
 269	unsigned char ch, flag;
 270
 271	/*
 272	 * This do { } while() loop will get ALL chars out of Rx FIFO 
 273         */
 274#ifndef CONFIG_XCOPILOT_BUGS
 275	do {
 276#endif	
 277		ch = GET_FIELD(rx, URX_RXDATA);
 278	
 279		if(info->is_cons) {
 280			if(URX_BREAK & rx) { /* whee, break received */
 281				return;
 282#ifdef CONFIG_MAGIC_SYSRQ
 283			} else if (ch == 0x10) { /* ^P */
 284				show_state();
 285				show_free_areas(0);
 286				show_buffers();
 287/*				show_net_buffers(); */
 288				return;
 289			} else if (ch == 0x12) { /* ^R */
 290				emergency_restart();
 291				return;
 292#endif /* CONFIG_MAGIC_SYSRQ */
 293			}
 294		}
 295
 296		if(!tty)
 297			goto clear_and_exit;
 298		
 299		flag = TTY_NORMAL;
 300
 301		if (rx & URX_PARITY_ERROR)
 302			flag = TTY_PARITY;
 303		else if (rx & URX_OVRUN)
 304			flag = TTY_OVERRUN;
 305		else if (rx & URX_FRAME_ERROR)
 306			flag = TTY_FRAME;
 307
 308		tty_insert_flip_char(tty, ch, flag);
 309#ifndef CONFIG_XCOPILOT_BUGS
 310	} while((rx = uart->urx.w) & URX_DATA_READY);
 311#endif
 312
 313	tty_schedule_flip(tty);
 314
 315clear_and_exit:
 316	return;
 317}
 318
 319static void transmit_chars(struct m68k_serial *info, struct tty_struct *tty)
 320{
 321	m68328_uart *uart = &uart_addr[info->line];
 322
 323	if (info->x_char) {
 324		/* Send next char */
 325		uart->utx.b.txdata = info->x_char;
 326		info->x_char = 0;
 327		goto clear_and_return;
 328	}
 329
 330	if ((info->xmit_cnt <= 0) || !tty || tty->stopped) {
 331		/* That's peculiar... TX ints off */
 332		uart->ustcnt &= ~USTCNT_TX_INTR_MASK;
 333		goto clear_and_return;
 334	}
 335
 336	/* Send char */
 337	uart->utx.b.txdata = info->xmit_buf[info->xmit_tail++];
 338	info->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
 339	info->xmit_cnt--;
 340
 341	if(info->xmit_cnt <= 0) {
 342		/* All done for now... TX ints off */
 343		uart->ustcnt &= ~USTCNT_TX_INTR_MASK;
 344		goto clear_and_return;
 345	}
 346
 347clear_and_return:
 348	/* Clear interrupt (should be auto)*/
 349	return;
 350}
 351
 352/*
 353 * This is the serial driver's generic interrupt routine
 354 */
 355irqreturn_t rs_interrupt(int irq, void *dev_id)
 356{
 357	struct m68k_serial *info = dev_id;
 358	struct tty_struct *tty = tty_port_tty_get(&info->tport);
 359	m68328_uart *uart;
 360	unsigned short rx;
 361	unsigned short tx;
 362
 363	uart = &uart_addr[info->line];
 364	rx = uart->urx.w;
 365
 366#ifdef USE_INTS
 367	tx = uart->utx.w;
 368
 369	if (rx & URX_DATA_READY)
 370		receive_chars(info, tty, rx);
 371	if (tx & UTX_TX_AVAIL)
 372		transmit_chars(info, tty);
 373#else
 374	receive_chars(info, tty, rx);
 375#endif
 376	tty_kref_put(tty);
 377
 378	return IRQ_HANDLED;
 379}
 380
 381static int startup(struct m68k_serial *info, struct tty_struct *tty)
 382{
 383	m68328_uart *uart = &uart_addr[info->line];
 384	unsigned long flags;
 385	
 386	if (info->tport.flags & ASYNC_INITIALIZED)
 387		return 0;
 388
 389	if (!info->xmit_buf) {
 390		info->xmit_buf = (unsigned char *) __get_free_page(GFP_KERNEL);
 391		if (!info->xmit_buf)
 392			return -ENOMEM;
 393	}
 394
 395	local_irq_save(flags);
 396
 397	/*
 398	 * Clear the FIFO buffers and disable them
 399	 * (they will be reenabled in change_speed())
 400	 */
 401
 402	uart->ustcnt = USTCNT_UEN;
 403	uart->ustcnt = USTCNT_UEN | USTCNT_RXEN | USTCNT_TXEN;
 404	(void)uart->urx.w;
 405
 406	/*
 407	 * Finally, enable sequencing and interrupts
 408	 */
 409#ifdef USE_INTS
 410	uart->ustcnt = USTCNT_UEN | USTCNT_RXEN | 
 411                 USTCNT_RX_INTR_MASK | USTCNT_TX_INTR_MASK;
 412#else
 413	uart->ustcnt = USTCNT_UEN | USTCNT_RXEN | USTCNT_RX_INTR_MASK;
 414#endif
 415
 416	if (tty)
 417		clear_bit(TTY_IO_ERROR, &tty->flags);
 418	info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
 419
 420	/*
 421	 * and set the speed of the serial port
 422	 */
 423
 424	change_speed(info, tty);
 425
 426	info->tport.flags |= ASYNC_INITIALIZED;
 427	local_irq_restore(flags);
 428	return 0;
 429}
 430
 431/*
 432 * This routine will shutdown a serial port; interrupts are disabled, and
 433 * DTR is dropped if the hangup on close termio flag is on.
 434 */
 435static void shutdown(struct m68k_serial *info, struct tty_struct *tty)
 436{
 437	m68328_uart *uart = &uart_addr[info->line];
 438	unsigned long	flags;
 439
 440	uart->ustcnt = 0; /* All off! */
 441	if (!(info->tport.flags & ASYNC_INITIALIZED))
 442		return;
 443
 444	local_irq_save(flags);
 445	
 446	if (info->xmit_buf) {
 447		free_page((unsigned long) info->xmit_buf);
 448		info->xmit_buf = 0;
 449	}
 450
 451	if (tty)
 452		set_bit(TTY_IO_ERROR, &tty->flags);
 453	
 454	info->tport.flags &= ~ASYNC_INITIALIZED;
 455	local_irq_restore(flags);
 456}
 457
 458struct {
 459	int divisor, prescale;
 460}
 461#ifndef CONFIG_M68VZ328
 462 hw_baud_table[18] = {
 463	{0,0}, /* 0 */
 464	{0,0}, /* 50 */
 465	{0,0}, /* 75 */
 466	{0,0}, /* 110 */
 467	{0,0}, /* 134 */
 468	{0,0}, /* 150 */
 469	{0,0}, /* 200 */
 470	{7,0x26}, /* 300 */
 471	{6,0x26}, /* 600 */
 472	{5,0x26}, /* 1200 */
 473	{0,0}, /* 1800 */
 474	{4,0x26}, /* 2400 */
 475	{3,0x26}, /* 4800 */
 476	{2,0x26}, /* 9600 */
 477	{1,0x26}, /* 19200 */
 478	{0,0x26}, /* 38400 */
 479	{1,0x38}, /* 57600 */
 480	{0,0x38}, /* 115200 */
 481};
 482#else
 483 hw_baud_table[18] = {
 484                 {0,0}, /* 0 */
 485                 {0,0}, /* 50 */
 486                 {0,0}, /* 75 */
 487                 {0,0}, /* 110 */
 488                 {0,0}, /* 134 */
 489                 {0,0}, /* 150 */
 490                 {0,0}, /* 200 */
 491                 {0,0}, /* 300 */
 492                 {7,0x26}, /* 600 */
 493                 {6,0x26}, /* 1200 */
 494                 {0,0}, /* 1800 */
 495                 {5,0x26}, /* 2400 */
 496                 {4,0x26}, /* 4800 */
 497                 {3,0x26}, /* 9600 */
 498                 {2,0x26}, /* 19200 */
 499                 {1,0x26}, /* 38400 */
 500                 {0,0x26}, /* 57600 */
 501                 {1,0x38}, /* 115200 */
 502}; 
 503#endif
 504/* rate = 1036800 / ((65 - prescale) * (1<<divider)) */
 505
 506/*
 507 * This routine is called to set the UART divisor registers to match
 508 * the specified baud rate for a serial port.
 509 */
 510static void change_speed(struct m68k_serial *info, struct tty_struct *tty)
 511{
 512	m68328_uart *uart = &uart_addr[info->line];
 513	unsigned short port;
 514	unsigned short ustcnt;
 515	unsigned cflag;
 516	int	i;
 517
 518	cflag = tty->termios->c_cflag;
 519	if (!(port = info->port))
 520		return;
 521
 522	ustcnt = uart->ustcnt;
 523	uart->ustcnt = ustcnt & ~USTCNT_TXEN;
 524
 525	i = cflag & CBAUD;
 526        if (i & CBAUDEX) {
 527                i = (i & ~CBAUDEX) + B38400;
 528        }
 529
 530	uart->ubaud = PUT_FIELD(UBAUD_DIVIDE,    hw_baud_table[i].divisor) | 
 531		PUT_FIELD(UBAUD_PRESCALER, hw_baud_table[i].prescale);
 532
 533	ustcnt &= ~(USTCNT_PARITYEN | USTCNT_ODD_EVEN | USTCNT_STOP | USTCNT_8_7);
 534	
 535	if ((cflag & CSIZE) == CS8)
 536		ustcnt |= USTCNT_8_7;
 537		
 538	if (cflag & CSTOPB)
 539		ustcnt |= USTCNT_STOP;
 540
 541	if (cflag & PARENB)
 542		ustcnt |= USTCNT_PARITYEN;
 543	if (cflag & PARODD)
 544		ustcnt |= USTCNT_ODD_EVEN;
 545	
 546#ifdef CONFIG_SERIAL_68328_RTS_CTS
 547	if (cflag & CRTSCTS) {
 548		uart->utx.w &= ~ UTX_NOCTS;
 549	} else {
 550		uart->utx.w |= UTX_NOCTS;
 551	}
 552#endif
 553
 554	ustcnt |= USTCNT_TXEN;
 555	
 556	uart->ustcnt = ustcnt;
 557	return;
 558}
 559
 560/*
 561 * Fair output driver allows a process to speak.
 562 */
 563static void rs_fair_output(void)
 564{
 565	int left;		/* Output no more than that */
 566	unsigned long flags;
 567	struct m68k_serial *info = &m68k_soft[0];
 568	char c;
 569
 570	if (info == 0) return;
 571	if (info->xmit_buf == 0) return;
 572
 573	local_irq_save(flags);
 574	left = info->xmit_cnt;
 575	while (left != 0) {
 576		c = info->xmit_buf[info->xmit_tail];
 577		info->xmit_tail = (info->xmit_tail+1) & (SERIAL_XMIT_SIZE-1);
 578		info->xmit_cnt--;
 579		local_irq_restore(flags);
 580
 581		rs_put_char(c);
 582
 583		local_irq_save(flags);
 584		left = min(info->xmit_cnt, left-1);
 585	}
 586
 587	/* Last character is being transmitted now (hopefully). */
 588	udelay(5);
 589
 590	local_irq_restore(flags);
 591	return;
 592}
 593
 594/*
 595 * m68k_console_print is registered for printk.
 596 */
 597void console_print_68328(const char *p)
 598{
 599	char c;
 600	
 601	while((c=*(p++)) != 0) {
 602		if(c == '\n')
 603			rs_put_char('\r');
 604		rs_put_char(c);
 605	}
 606
 607	/* Comment this if you want to have a strict interrupt-driven output */
 608	rs_fair_output();
 609
 610	return;
 611}
 612
 613static void rs_set_ldisc(struct tty_struct *tty)
 614{
 615	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
 616
 617	if (serial_paranoia_check(info, tty->name, "rs_set_ldisc"))
 618		return;
 619
 620	info->is_cons = (tty->termios->c_line == N_TTY);
 621	
 622	printk("ttyS%d console mode %s\n", info->line, info->is_cons ? "on" : "off");
 623}
 624
 625static void rs_flush_chars(struct tty_struct *tty)
 626{
 627	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
 628	m68328_uart *uart = &uart_addr[info->line];
 629	unsigned long flags;
 630
 631	if (serial_paranoia_check(info, tty->name, "rs_flush_chars"))
 632		return;
 633#ifndef USE_INTS
 634	for(;;) {
 635#endif
 636
 637	/* Enable transmitter */
 638	local_irq_save(flags);
 639
 640	if (info->xmit_cnt <= 0 || tty->stopped || tty->hw_stopped ||
 641			!info->xmit_buf) {
 642		local_irq_restore(flags);
 643		return;
 644	}
 645
 646#ifdef USE_INTS
 647	uart->ustcnt |= USTCNT_TXEN | USTCNT_TX_INTR_MASK;
 648#else
 649	uart->ustcnt |= USTCNT_TXEN;
 650#endif
 651
 652#ifdef USE_INTS
 653	if (uart->utx.w & UTX_TX_AVAIL) {
 654#else
 655	if (1) {
 656#endif
 657		/* Send char */
 658		uart->utx.b.txdata = info->xmit_buf[info->xmit_tail++];
 659		info->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
 660		info->xmit_cnt--;
 661	}
 662
 663#ifndef USE_INTS
 664	while (!(uart->utx.w & UTX_TX_AVAIL)) udelay(5);
 665	}
 666#endif
 667	local_irq_restore(flags);
 668}
 669
 670extern void console_printn(const char * b, int count);
 671
 672static int rs_write(struct tty_struct * tty,
 673		    const unsigned char *buf, int count)
 674{
 675	int	c, total = 0;
 676	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
 677	m68328_uart *uart = &uart_addr[info->line];
 678	unsigned long flags;
 679
 680	if (serial_paranoia_check(info, tty->name, "rs_write"))
 681		return 0;
 682
 683	if (!tty || !info->xmit_buf)
 684		return 0;
 685
 686	local_save_flags(flags);
 687	while (1) {
 688		local_irq_disable();		
 689		c = min_t(int, count, min(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
 690				   SERIAL_XMIT_SIZE - info->xmit_head));
 691		local_irq_restore(flags);
 692
 693		if (c <= 0)
 694			break;
 695
 696		memcpy(info->xmit_buf + info->xmit_head, buf, c);
 697
 698		local_irq_disable();
 699		info->xmit_head = (info->xmit_head + c) & (SERIAL_XMIT_SIZE-1);
 700		info->xmit_cnt += c;
 701		local_irq_restore(flags);
 702		buf += c;
 703		count -= c;
 704		total += c;
 705	}
 706
 707	if (info->xmit_cnt && !tty->stopped && !tty->hw_stopped) {
 708		/* Enable transmitter */
 709		local_irq_disable();		
 710#ifndef USE_INTS
 711		while(info->xmit_cnt) {
 712#endif
 713
 714		uart->ustcnt |= USTCNT_TXEN;
 715#ifdef USE_INTS
 716		uart->ustcnt |= USTCNT_TX_INTR_MASK;
 717#else
 718		while (!(uart->utx.w & UTX_TX_AVAIL)) udelay(5);
 719#endif
 720		if (uart->utx.w & UTX_TX_AVAIL) {
 721			uart->utx.b.txdata = info->xmit_buf[info->xmit_tail++];
 722			info->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
 723			info->xmit_cnt--;
 724		}
 725
 726#ifndef USE_INTS
 727		}
 728#endif
 729		local_irq_restore(flags);
 730	}
 731
 732	return total;
 733}
 734
 735static int rs_write_room(struct tty_struct *tty)
 736{
 737	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
 738	int	ret;
 739				
 740	if (serial_paranoia_check(info, tty->name, "rs_write_room"))
 741		return 0;
 742	ret = SERIAL_XMIT_SIZE - info->xmit_cnt - 1;
 743	if (ret < 0)
 744		ret = 0;
 745	return ret;
 746}
 747
 748static int rs_chars_in_buffer(struct tty_struct *tty)
 749{
 750	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
 751				
 752	if (serial_paranoia_check(info, tty->name, "rs_chars_in_buffer"))
 753		return 0;
 754	return info->xmit_cnt;
 755}
 756
 757static void rs_flush_buffer(struct tty_struct *tty)
 758{
 759	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
 760	unsigned long flags;
 761				
 762	if (serial_paranoia_check(info, tty->name, "rs_flush_buffer"))
 763		return;
 764	local_irq_save(flags);
 765	info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
 766	local_irq_restore(flags);
 767	tty_wakeup(tty);
 768}
 769
 770/*
 771 * ------------------------------------------------------------
 772 * rs_throttle()
 773 * 
 774 * This routine is called by the upper-layer tty layer to signal that
 775 * incoming characters should be throttled.
 776 * ------------------------------------------------------------
 777 */
 778static void rs_throttle(struct tty_struct * tty)
 779{
 780	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
 781
 782	if (serial_paranoia_check(info, tty->name, "rs_throttle"))
 783		return;
 784	
 785	if (I_IXOFF(tty))
 786		info->x_char = STOP_CHAR(tty);
 787
 788	/* Turn off RTS line (do this atomic) */
 789}
 790
 791static void rs_unthrottle(struct tty_struct * tty)
 792{
 793	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
 794
 795	if (serial_paranoia_check(info, tty->name, "rs_unthrottle"))
 796		return;
 797	
 798	if (I_IXOFF(tty)) {
 799		if (info->x_char)
 800			info->x_char = 0;
 801		else
 802			info->x_char = START_CHAR(tty);
 803	}
 804
 805	/* Assert RTS line (do this atomic) */
 806}
 807
 808/*
 809 * ------------------------------------------------------------
 810 * rs_ioctl() and friends
 811 * ------------------------------------------------------------
 812 */
 813
 814static int get_serial_info(struct m68k_serial * info,
 815			   struct serial_struct * retinfo)
 816{
 817	struct serial_struct tmp;
 818  
 819	if (!retinfo)
 820		return -EFAULT;
 821	memset(&tmp, 0, sizeof(tmp));
 822	tmp.type = info->type;
 823	tmp.line = info->line;
 824	tmp.port = info->port;
 825	tmp.irq = info->irq;
 826	tmp.flags = info->tport.flags;
 827	tmp.baud_base = info->baud_base;
 828	tmp.close_delay = info->tport.close_delay;
 829	tmp.closing_wait = info->tport.closing_wait;
 830	tmp.custom_divisor = info->custom_divisor;
 831	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
 832		return -EFAULT;
 833
 834	return 0;
 835}
 836
 837static int set_serial_info(struct m68k_serial *info, struct tty_struct *tty,
 838			   struct serial_struct * new_info)
 839{
 840	struct tty_port *port = &info->tport;
 841	struct serial_struct new_serial;
 842	struct m68k_serial old_info;
 843	int 			retval = 0;
 844
 845	if (!new_info)
 846		return -EFAULT;
 847	if (copy_from_user(&new_serial, new_info, sizeof(new_serial)))
 848		return -EFAULT;
 849	old_info = *info;
 850
 851	if (!capable(CAP_SYS_ADMIN)) {
 852		if ((new_serial.baud_base != info->baud_base) ||
 853		    (new_serial.type != info->type) ||
 854		    (new_serial.close_delay != port->close_delay) ||
 855		    ((new_serial.flags & ~ASYNC_USR_MASK) !=
 856		     (port->flags & ~ASYNC_USR_MASK)))
 857			return -EPERM;
 858		port->flags = ((port->flags & ~ASYNC_USR_MASK) |
 859			       (new_serial.flags & ASYNC_USR_MASK));
 860		info->custom_divisor = new_serial.custom_divisor;
 861		goto check_and_exit;
 862	}
 863
 864	if (port->count > 1)
 865		return -EBUSY;
 866
 867	/*
 868	 * OK, past this point, all the error checking has been done.
 869	 * At this point, we start making changes.....
 870	 */
 871
 872	info->baud_base = new_serial.baud_base;
 873	port->flags = ((port->flags & ~ASYNC_FLAGS) |
 874			(new_serial.flags & ASYNC_FLAGS));
 875	info->type = new_serial.type;
 876	port->close_delay = new_serial.close_delay;
 877	port->closing_wait = new_serial.closing_wait;
 878
 879check_and_exit:
 880	retval = startup(info, tty);
 881	return retval;
 882}
 883
 884/*
 885 * get_lsr_info - get line status register info
 886 *
 887 * Purpose: Let user call ioctl() to get info when the UART physically
 888 * 	    is emptied.  On bus types like RS485, the transmitter must
 889 * 	    release the bus after transmitting. This must be done when
 890 * 	    the transmit shift register is empty, not be done when the
 891 * 	    transmit holding register is empty.  This functionality
 892 * 	    allows an RS485 driver to be written in user space. 
 893 */
 894static int get_lsr_info(struct m68k_serial * info, unsigned int *value)
 895{
 896#ifdef CONFIG_SERIAL_68328_RTS_CTS
 897	m68328_uart *uart = &uart_addr[info->line];
 898#endif
 899	unsigned char status;
 900	unsigned long flags;
 901
 902	local_irq_save(flags);
 903#ifdef CONFIG_SERIAL_68328_RTS_CTS
 904	status = (uart->utx.w & UTX_CTS_STAT) ? 1 : 0;
 905#else
 906	status = 0;
 907#endif
 908	local_irq_restore(flags);
 909	return put_user(status, value);
 910}
 911
 912/*
 913 * This routine sends a break character out the serial port.
 914 */
 915static void send_break(struct m68k_serial * info, unsigned int duration)
 916{
 917	m68328_uart *uart = &uart_addr[info->line];
 918        unsigned long flags;
 919        if (!info->port)
 920                return;
 921        local_irq_save(flags);
 922#ifdef USE_INTS	
 923	uart->utx.w |= UTX_SEND_BREAK;
 924	msleep_interruptible(duration);
 925	uart->utx.w &= ~UTX_SEND_BREAK;
 926#endif		
 927        local_irq_restore(flags);
 928}
 929
 930static int rs_ioctl(struct tty_struct *tty,
 931		    unsigned int cmd, unsigned long arg)
 932{
 933	struct m68k_serial * info = (struct m68k_serial *)tty->driver_data;
 934	int retval;
 935
 936	if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
 937		return -ENODEV;
 938
 939	if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
 940	    (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGWILD)  &&
 941	    (cmd != TIOCSERSWILD) && (cmd != TIOCSERGSTRUCT)) {
 942		if (tty->flags & (1 << TTY_IO_ERROR))
 943		    return -EIO;
 944	}
 945	
 946	switch (cmd) {
 947		case TCSBRK:	/* SVID version: non-zero arg --> no break */
 948			retval = tty_check_change(tty);
 949			if (retval)
 950				return retval;
 951			tty_wait_until_sent(tty, 0);
 952			if (!arg)
 953				send_break(info, 250);	/* 1/4 second */
 954			return 0;
 955		case TCSBRKP:	/* support for POSIX tcsendbreak() */
 956			retval = tty_check_change(tty);
 957			if (retval)
 958				return retval;
 959			tty_wait_until_sent(tty, 0);
 960			send_break(info, arg ? arg*(100) : 250);
 961			return 0;
 962		case TIOCGSERIAL:
 963			return get_serial_info(info,
 964				       (struct serial_struct *) arg);
 965		case TIOCSSERIAL:
 966			return set_serial_info(info, tty,
 967					       (struct serial_struct *) arg);
 968		case TIOCSERGETLSR: /* Get line status register */
 969			return get_lsr_info(info, (unsigned int *) arg);
 970		case TIOCSERGSTRUCT:
 971			if (copy_to_user((struct m68k_serial *) arg,
 972				    info, sizeof(struct m68k_serial)))
 973				return -EFAULT;
 974			return 0;
 975		default:
 976			return -ENOIOCTLCMD;
 977		}
 978	return 0;
 979}
 980
 981static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
 982{
 983	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
 984
 985	change_speed(info, tty);
 986
 987	if ((old_termios->c_cflag & CRTSCTS) &&
 988	    !(tty->termios->c_cflag & CRTSCTS)) {
 989		tty->hw_stopped = 0;
 990		rs_start(tty);
 991	}
 992	
 993}
 994
 995/*
 996 * ------------------------------------------------------------
 997 * rs_close()
 998 * 
 999 * This routine is called when the serial port gets closed.  First, we
1000 * wait for the last remaining data to be sent.  Then, we unlink its
1001 * S structure from the interrupt chain if necessary, and we free
1002 * that IRQ if nothing is left in the chain.
1003 * ------------------------------------------------------------
1004 */
1005static void rs_close(struct tty_struct *tty, struct file * filp)
1006{
1007	struct m68k_serial * info = (struct m68k_serial *)tty->driver_data;
1008	struct tty_port *port = &info->tport;
1009	m68328_uart *uart = &uart_addr[info->line];
1010	unsigned long flags;
1011
1012	if (!info || serial_paranoia_check(info, tty->name, "rs_close"))
1013		return;
1014	
1015	local_irq_save(flags);
1016	
1017	if (tty_hung_up_p(filp)) {
1018		local_irq_restore(flags);
1019		return;
1020	}
1021	
1022	if ((tty->count == 1) && (port->count != 1)) {
1023		/*
1024		 * Uh, oh.  tty->count is 1, which means that the tty
1025		 * structure will be freed.  Info->count should always
1026		 * be one in these conditions.  If it's greater than
1027		 * one, we've got real problems, since it means the
1028		 * serial port won't be shutdown.
1029		 */
1030		printk("rs_close: bad serial port count; tty->count is 1, "
1031		       "port->count is %d\n", port->count);
1032		port->count = 1;
1033	}
1034	if (--port->count < 0) {
1035		printk("rs_close: bad serial port count for ttyS%d: %d\n",
1036		       info->line, port->count);
1037		port->count = 0;
1038	}
1039	if (port->count) {
1040		local_irq_restore(flags);
1041		return;
1042	}
1043	port->flags |= ASYNC_CLOSING;
1044	/*
1045	 * Now we wait for the transmit buffer to clear; and we notify 
1046	 * the line discipline to only process XON/XOFF characters.
1047	 */
1048	tty->closing = 1;
1049	if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
1050		tty_wait_until_sent(tty, port->closing_wait);
1051	/*
1052	 * At this point we stop accepting input.  To do this, we
1053	 * disable the receive line status interrupts, and tell the
1054	 * interrupt driver to stop checking the data ready bit in the
1055	 * line status register.
1056	 */
1057
1058	uart->ustcnt &= ~USTCNT_RXEN;
1059	uart->ustcnt &= ~(USTCNT_RXEN | USTCNT_RX_INTR_MASK);
1060
1061	shutdown(info, tty);
1062	rs_flush_buffer(tty);
1063		
1064	tty_ldisc_flush(tty);
1065	tty->closing = 0;
1066	tty_port_tty_set(&info->tport, NULL);
1067#warning "This is not and has never been valid so fix it"	
1068#if 0
1069	if (tty->ldisc.num != ldiscs[N_TTY].num) {
1070		if (tty->ldisc.close)
1071			(tty->ldisc.close)(tty);
1072		tty->ldisc = ldiscs[N_TTY];
1073		tty->termios->c_line = N_TTY;
1074		if (tty->ldisc.open)
1075			(tty->ldisc.open)(tty);
1076	}
1077#endif	
1078	if (port->blocked_open) {
1079		if (port->close_delay)
1080			msleep_interruptible(jiffies_to_msecs(port->close_delay));
1081		wake_up_interruptible(&port->open_wait);
1082	}
1083	port->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
1084	wake_up_interruptible(&port->close_wait);
1085	local_irq_restore(flags);
1086}
1087
1088/*
1089 * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
1090 */
1091void rs_hangup(struct tty_struct *tty)
1092{
1093	struct m68k_serial * info = (struct m68k_serial *)tty->driver_data;
1094	
1095	if (serial_paranoia_check(info, tty->name, "rs_hangup"))
1096		return;
1097	
1098	rs_flush_buffer(tty);
1099	shutdown(info, tty);
1100	info->tport.count = 0;
1101	info->tport.flags &= ~ASYNC_NORMAL_ACTIVE;
1102	tty_port_tty_set(&info->tport, NULL);
1103	wake_up_interruptible(&info->tport.open_wait);
1104}
1105
1106/*
1107 * This routine is called whenever a serial port is opened.  It
1108 * enables interrupts for a serial port, linking in its S structure into
1109 * the IRQ chain.   It also performs the serial-specific
1110 * initialization for the tty structure.
1111 */
1112int rs_open(struct tty_struct *tty, struct file * filp)
1113{
1114	struct m68k_serial	*info;
1115	int retval;
1116
1117	info = &m68k_soft[tty->index];
1118
1119	if (serial_paranoia_check(info, tty->name, "rs_open"))
1120		return -ENODEV;
1121
1122	info->tport.count++;
1123	tty->driver_data = info;
1124	tty_port_tty_set(&info->tport, tty);
1125
1126	/*
1127	 * Start up serial port
1128	 */
1129	retval = startup(info, tty);
1130	if (retval)
1131		return retval;
1132
1133	return tty_port_block_til_ready(&info->tport, tty, filp);
1134}
1135
1136/* Finally, routines used to initialize the serial driver. */
1137
1138static void show_serial_version(void)
1139{
1140	printk("MC68328 serial driver version 1.00\n");
1141}
1142
1143static const struct tty_operations rs_ops = {
1144	.open = rs_open,
1145	.close = rs_close,
1146	.write = rs_write,
1147	.flush_chars = rs_flush_chars,
1148	.write_room = rs_write_room,
1149	.chars_in_buffer = rs_chars_in_buffer,
1150	.flush_buffer = rs_flush_buffer,
1151	.ioctl = rs_ioctl,
1152	.throttle = rs_throttle,
1153	.unthrottle = rs_unthrottle,
1154	.set_termios = rs_set_termios,
1155	.stop = rs_stop,
1156	.start = rs_start,
1157	.hangup = rs_hangup,
1158	.set_ldisc = rs_set_ldisc,
1159};
1160
1161static const struct tty_port_operations rs_port_ops = {
1162};
1163
1164/* rs_init inits the driver */
1165static int __init
1166rs68328_init(void)
1167{
1168	unsigned long flags;
1169	int i;
1170	struct m68k_serial *info;
1171
1172	serial_driver = alloc_tty_driver(NR_PORTS);
1173	if (!serial_driver)
1174		return -ENOMEM;
1175
1176	show_serial_version();
1177
1178	/* Initialize the tty_driver structure */
1179	/* SPARC: Not all of this is exactly right for us. */
1180	
1181	serial_driver->name = "ttyS";
1182	serial_driver->major = TTY_MAJOR;
1183	serial_driver->minor_start = 64;
1184	serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
1185	serial_driver->subtype = SERIAL_TYPE_NORMAL;
1186	serial_driver->init_termios = tty_std_termios;
1187	serial_driver->init_termios.c_cflag = 
1188			m68328_console_cbaud | CS8 | CREAD | HUPCL | CLOCAL;
1189	serial_driver->flags = TTY_DRIVER_REAL_RAW;
1190	tty_set_operations(serial_driver, &rs_ops);
1191
1192	if (tty_register_driver(serial_driver)) {
1193		put_tty_driver(serial_driver);
1194		printk(KERN_ERR "Couldn't register serial driver\n");
1195		return -ENOMEM;
1196	}
1197
1198	local_irq_save(flags);
1199
1200	for(i=0;i<NR_PORTS;i++) {
1201
1202	    info = &m68k_soft[i];
1203	    tty_port_init(&info->tport);
1204	    info->tport.ops = &rs_port_ops;
1205	    info->magic = SERIAL_MAGIC;
1206	    info->port = (int) &uart_addr[i];
1207	    info->irq = uart_irqs[i];
1208	    info->custom_divisor = 16;
1209	    info->x_char = 0;
1210	    info->line = i;
1211	    info->is_cons = 1; /* Means shortcuts work */
1212	    
1213	    printk("%s%d at 0x%08x (irq = %d)", serial_driver->name, info->line, 
1214		   info->port, info->irq);
1215	    printk(" is a builtin MC68328 UART\n");
1216	    
1217#ifdef CONFIG_M68VZ328
1218		if (i > 0 )
1219			PJSEL &= 0xCF;  /* PSW enable second port output */
1220#endif
1221
1222	    if (request_irq(uart_irqs[i],
1223			    rs_interrupt,
1224			    0,
1225			    "M68328_UART", info))
1226                panic("Unable to attach 68328 serial interrupt\n");
1227	}
1228	local_irq_restore(flags);
1229	return 0;
1230}
1231
1232module_init(rs68328_init);
1233
1234
1235
1236static void m68328_set_baud(void)
1237{
1238	unsigned short ustcnt;
1239	int	i;
1240
1241	ustcnt = USTCNT;
1242	USTCNT = ustcnt & ~USTCNT_TXEN;
1243
1244again:
1245	for (i = 0; i < ARRAY_SIZE(baud_table); i++)
1246		if (baud_table[i] == m68328_console_baud)
1247			break;
1248	if (i >= ARRAY_SIZE(baud_table)) {
1249		m68328_console_baud = 9600;
1250		goto again;
1251	}
1252
1253	UBAUD = PUT_FIELD(UBAUD_DIVIDE,    hw_baud_table[i].divisor) | 
1254		PUT_FIELD(UBAUD_PRESCALER, hw_baud_table[i].prescale);
1255	ustcnt &= ~(USTCNT_PARITYEN | USTCNT_ODD_EVEN | USTCNT_STOP | USTCNT_8_7);
1256	ustcnt |= USTCNT_8_7;
1257	ustcnt |= USTCNT_TXEN;
1258	USTCNT = ustcnt;
1259	m68328_console_initted = 1;
1260	return;
1261}
1262
1263
1264int m68328_console_setup(struct console *cp, char *arg)
1265{
1266	int		i, n = CONSOLE_BAUD_RATE;
1267
1268	if (!cp)
1269		return(-1);
1270
1271	if (arg)
1272		n = simple_strtoul(arg,NULL,0);
1273
1274	for (i = 0; i < ARRAY_SIZE(baud_table); i++)
1275		if (baud_table[i] == n)
1276			break;
1277	if (i < ARRAY_SIZE(baud_table)) {
1278		m68328_console_baud = n;
1279		m68328_console_cbaud = 0;
1280		if (i > 15) {
1281			m68328_console_cbaud |= CBAUDEX;
1282			i -= 15;
1283		}
1284		m68328_console_cbaud |= i;
1285	}
1286
1287	m68328_set_baud(); /* make sure baud rate changes */
1288	return(0);
1289}
1290
1291
1292static struct tty_driver *m68328_console_device(struct console *c, int *index)
1293{
1294	*index = c->index;
1295	return serial_driver;
1296}
1297
1298
1299void m68328_console_write (struct console *co, const char *str,
1300			   unsigned int count)
1301{
1302	if (!m68328_console_initted)
1303		m68328_set_baud();
1304    while (count--) {
1305        if (*str == '\n')
1306           rs_put_char('\r');
1307        rs_put_char( *str++ );
1308    }
1309}
1310
1311
1312static struct console m68328_driver = {
1313	.name		= "ttyS",
1314	.write		= m68328_console_write,
1315	.device		= m68328_console_device,
1316	.setup		= m68328_console_setup,
1317	.flags		= CON_PRINTBUFFER,
1318	.index		= -1,
1319};
1320
1321
1322static int __init m68328_console_init(void)
1323{
1324	register_console(&m68328_driver);
1325	return 0;
1326}
1327
1328console_initcall(m68328_console_init);