text: /* 68328serial.c: Serial port driver for 68328 microcontroller
   *
   * Copyright (C) 1995       David S. Miller    <davem@caip.rutgers.edu>
   * Copyright (C) 1998       Kenneth Albanowski <kjahds@kjahds.com>
   * Copyright (C) 1998, 1999 D. Jeff Dionne     <jeff@uclinux.org>
   * Copyright (C) 1999       Vladimir Gurevich  <vgurevic@cisco.com>
   * Copyright (C) 2002-2003  David McCullough   <davidm@snapgear.com>
   * Copyright (C) 2002       Greg Ungerer       <gerg@snapgear.com>
   *
   * VZ Support/Fixes             Evan Stawnyczy <e@lineo.ca>
   * Multiple UART support        Daniel Potts <danielp@cse.unsw.edu.au>
   * Power management support     Daniel Potts <danielp@cse.unsw.edu.au>
   * VZ Second Serial Port enable Phil Wilshire
   * 2.4/2.5 port                 David McCullough
   */
  
  #include <asm/dbg.h>
  #include <linux/module.h>
  #include <linux/errno.h>
  #include <linux/serial.h>
  #include <linux/signal.h>
  #include <linux/sched.h>
  #include <linux/timer.h>
  #include <linux/interrupt.h>
  #include <linux/tty.h>
  #include <linux/tty_flip.h>
  #include <linux/major.h>
  #include <linux/string.h>
  #include <linux/fcntl.h>
  #include <linux/mm.h>
  #include <linux/kernel.h>
  #include <linux/console.h>
  #include <linux/reboot.h>
  #include <linux/keyboard.h>
  #include <linux/init.h>
  #include <linux/pm.h>
  #include <linux/bitops.h>
  #include <linux/delay.h>
  #include <linux/gfp.h>
  
  #include <asm/io.h>
  #include <asm/irq.h>
  #include <asm/delay.h>
  #include <asm/uaccess.h>
  
  /* (es) */
  /* note: perhaps we can murge these files, so that you can just
   * 	 define 1 of them, and they can sort that out for themselves
   */
  #if defined(CONFIG_M68EZ328)
  #include <asm/MC68EZ328.h>
  #else
  #if defined(CONFIG_M68VZ328)
  #include <asm/MC68VZ328.h>
  #else
  #include <asm/MC68328.h>
  #endif /* CONFIG_M68VZ328 */
  #endif /* CONFIG_M68EZ328 */
  
  /* Turn off usage of real serial interrupt code, to "support" Copilot */
  #ifdef CONFIG_XCOPILOT_BUGS
  #undef USE_INTS
  #else
  #define USE_INTS
  #endif
  
  /*
   * I believe this is the optimal setting that reduces the number of interrupts.
   * At high speeds the output might become a little "bursted" (use USTCNT_TXHE
   * if that bothers you), but in most cases it will not, since we try to
   * transmit characters every time rs_interrupt is called. Thus, quite often
   * you'll see that a receive interrupt occures before the transmit one.
   *                                  -- Vladimir Gurevich
   */
  #define USTCNT_TX_INTR_MASK (USTCNT_TXEE)
  
  /*
   * 68328 and 68EZ328 UARTS are a little bit different. EZ328 has special
   * "Old data interrupt" which occures whenever the data stay in the FIFO
   * longer than 30 bits time. This allows us to use FIFO without compromising
   * latency. '328 does not have this feature and without the real  328-based
   * board I would assume that RXRE is the safest setting.
   *
   * For EZ328 I use RXHE (Half empty) interrupt to reduce the number of
   * interrupts. RXFE (receive queue full) causes the system to lose data
   * at least at 115200 baud
   *
   * If your board is busy doing other stuff, you might consider to use
   * RXRE (data ready intrrupt) instead.
   *
   * The other option is to make these INTR masks run-time configurable, so
   * that people can dynamically adapt them according to the current usage.
   *                                  -- Vladimir Gurevich
   */
  
  /* (es) */
  #if defined(CONFIG_M68EZ328) || defined(CONFIG_M68VZ328)
  #define USTCNT_RX_INTR_MASK (USTCNT_RXHE | USTCNT_ODEN)
  #elif defined(CONFIG_M68328)
  #define USTCNT_RX_INTR_MASK (USTCNT_RXRE)
  #else
  #error Please, define the Rx interrupt events for your CPU
  #endif
  /* (/es) */
  
  /*
   * This is our internal structure for each serial port's state.
   */
  struct m68k_serial {
  	struct tty_port		tport;
  	char			is_cons;	/* Is this our console. */
  	int			magic;
  	int			baud_base;
  	int			port;
  	int			irq;
  	int			type;		/* UART type */
  	int			custom_divisor;
  	int			x_char;		/* xon/xoff character */
  	int			line;
  	unsigned char		*xmit_buf;
  	int			xmit_head;
  	int			xmit_tail;
  	int			xmit_cnt;
  };
  
  #define SERIAL_MAGIC 0x5301
  
  /*
   * Define the number of ports supported and their irqs.
   */
  #define NR_PORTS 1
  
  static struct m68k_serial m68k_soft[NR_PORTS];
  
  static unsigned int uart_irqs[NR_PORTS] = { UART_IRQ_NUM };
  
  /* multiple ports are contiguous in memory */
  m68328_uart *uart_addr = (m68328_uart *)USTCNT_ADDR;
  
  struct tty_driver *serial_driver;
  
  static void change_speed(struct m68k_serial *info, struct tty_struct *tty);
  
  /*
   *	Setup for console. Argument comes from the boot command line.
   */
  
  /* note: this is messy, but it works, again, perhaps defined somewhere else?*/
  #ifdef CONFIG_M68VZ328
  #define CONSOLE_BAUD_RATE	19200
  #define DEFAULT_CBAUD		B19200
  #endif
  
  
  #ifndef CONSOLE_BAUD_RATE
  #define	CONSOLE_BAUD_RATE	9600
  #define	DEFAULT_CBAUD		B9600
  #endif
  
  
  static int m68328_console_initted = 0;
  static int m68328_console_baud    = CONSOLE_BAUD_RATE;
  static int m68328_console_cbaud   = DEFAULT_CBAUD;
  
  
  static inline int serial_paranoia_check(struct m68k_serial *info,
  					char *name, const char *routine)
  {
  #ifdef SERIAL_PARANOIA_CHECK
  	static const char *badmagic =
  		"Warning: bad magic number for serial struct %s in %s\n";
  	static const char *badinfo =
  		"Warning: null m68k_serial for %s in %s\n";
  
  	if (!info) {
  		printk(badinfo, name, routine);
  		return 1;
  	}
  	if (info->magic != SERIAL_MAGIC) {
  		printk(badmagic, name, routine);
  		return 1;
  	}
  #endif
  	return 0;
  }
  
  /*
   * This is used to figure out the divisor speeds and the timeouts
   */
  static int baud_table[] = {
  	0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
  	9600, 19200, 38400, 57600, 115200, 0 };
  
  /* Utility routines */
  static inline int get_baud(struct m68k_serial *ss)
  {
  	unsigned long result = 115200;
  	unsigned short int baud = uart_addr[ss->line].ubaud;
  	if (GET_FIELD(baud, UBAUD_PRESCALER) == 0x38) result = 38400;
  	result >>= GET_FIELD(baud, UBAUD_DIVIDE);
  
  	return result;
  }
  
  /*
   * ------------------------------------------------------------
   * rs_stop() and rs_start()
   *
   * This routines are called before setting or resetting tty->stopped.
   * They enable or disable transmitter interrupts, as necessary.
   * ------------------------------------------------------------
   */
  static void rs_stop(struct tty_struct *tty)
  {
  	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
  	m68328_uart *uart = &uart_addr[info->line];
  	unsigned long flags;
  
  	if (serial_paranoia_check(info, tty->name, "rs_stop"))
  		return;
  	
  	local_irq_save(flags);
  	uart->ustcnt &= ~USTCNT_TXEN;
  	local_irq_restore(flags);
  }
  
  static int rs_put_char(char ch)
  {
  	unsigned long flags;
  	int loops = 0;
  
          local_irq_save(flags);
  
  	while (!(UTX & UTX_TX_AVAIL) && (loops < 1000)) {
          	loops++;
          	udelay(5);
          }
  
  	UTX_TXDATA = ch;
          udelay(5);
          local_irq_restore(flags);
          return 1;
  }
  
  static void rs_start(struct tty_struct *tty)
  {
  	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
  	m68328_uart *uart = &uart_addr[info->line];
  	unsigned long flags;
  	
  	if (serial_paranoia_check(info, tty->name, "rs_start"))
  		return;
  	
  	local_irq_save(flags);
  	if (info->xmit_cnt && info->xmit_buf && !(uart->ustcnt & USTCNT_TXEN)) {
  #ifdef USE_INTS
  		uart->ustcnt |= USTCNT_TXEN | USTCNT_TX_INTR_MASK;
  #else
  		uart->ustcnt |= USTCNT_TXEN;
  #endif
  	}
  	local_irq_restore(flags);
  }
  
  static void receive_chars(struct m68k_serial *info, struct tty_struct *tty,
  		unsigned short rx)
  {
  	m68328_uart *uart = &uart_addr[info->line];
  	unsigned char ch, flag;
  
  	/*
  	 * This do { } while() loop will get ALL chars out of Rx FIFO 
           */
  #ifndef CONFIG_XCOPILOT_BUGS
  	do {
  #endif	
  		ch = GET_FIELD(rx, URX_RXDATA);
  	
  		if(info->is_cons) {
  			if(URX_BREAK & rx) { /* whee, break received */
  				return;
  #ifdef CONFIG_MAGIC_SYSRQ
  			} else if (ch == 0x10) { /* ^P */
  				show_state();
  				show_free_areas(0);
  				show_buffers();
  /*				show_net_buffers(); */
  				return;
  			} else if (ch == 0x12) { /* ^R */
  				emergency_restart();
  				return;
  #endif /* CONFIG_MAGIC_SYSRQ */
  			}
  		}
  
  		if(!tty)
  			goto clear_and_exit;
  		
  		flag = TTY_NORMAL;
  
  		if (rx & URX_PARITY_ERROR)
  			flag = TTY_PARITY;
  		else if (rx & URX_OVRUN)
  			flag = TTY_OVERRUN;
  		else if (rx & URX_FRAME_ERROR)
  			flag = TTY_FRAME;
  
  		tty_insert_flip_char(tty, ch, flag);
  #ifndef CONFIG_XCOPILOT_BUGS
  	} while((rx = uart->urx.w) & URX_DATA_READY);
  #endif
  
  	tty_schedule_flip(tty);
  
  clear_and_exit:
  	return;
  }
  
  static void transmit_chars(struct m68k_serial *info, struct tty_struct *tty)
  {
  	m68328_uart *uart = &uart_addr[info->line];
  
  	if (info->x_char) {
  		/* Send next char */
  		uart->utx.b.txdata = info->x_char;
  		info->x_char = 0;
  		goto clear_and_return;
  	}
  
  	if ((info->xmit_cnt <= 0) || !tty || tty->stopped) {
  		/* That's peculiar... TX ints off */
  		uart->ustcnt &= ~USTCNT_TX_INTR_MASK;
  		goto clear_and_return;
  	}
  
  	/* Send char */
  	uart->utx.b.txdata = info->xmit_buf[info->xmit_tail++];
  	info->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
  	info->xmit_cnt--;
  
  	if(info->xmit_cnt <= 0) {
  		/* All done for now... TX ints off */
  		uart->ustcnt &= ~USTCNT_TX_INTR_MASK;
  		goto clear_and_return;
  	}
  
  clear_and_return:
  	/* Clear interrupt (should be auto)*/
  	return;
  }
  
  /*
   * This is the serial driver's generic interrupt routine
   */
  irqreturn_t rs_interrupt(int irq, void *dev_id)
  {
  	struct m68k_serial *info = dev_id;
  	struct tty_struct *tty = tty_port_tty_get(&info->tport);
  	m68328_uart *uart;
  	unsigned short rx;
  	unsigned short tx;
  
  	uart = &uart_addr[info->line];
  	rx = uart->urx.w;
  
  #ifdef USE_INTS
  	tx = uart->utx.w;
  
  	if (rx & URX_DATA_READY)
  		receive_chars(info, tty, rx);
  	if (tx & UTX_TX_AVAIL)
  		transmit_chars(info, tty);
  #else
  	receive_chars(info, tty, rx);
  #endif
  	tty_kref_put(tty);
  
  	return IRQ_HANDLED;
  }
  
  static int startup(struct m68k_serial *info, struct tty_struct *tty)
  {
  	m68328_uart *uart = &uart_addr[info->line];
  	unsigned long flags;
  	
  	if (info->tport.flags & ASYNC_INITIALIZED)
  		return 0;
  
  	if (!info->xmit_buf) {
  		info->xmit_buf = (unsigned char *) __get_free_page(GFP_KERNEL);
  		if (!info->xmit_buf)
  			return -ENOMEM;
  	}
  
  	local_irq_save(flags);
  
  	/*
  	 * Clear the FIFO buffers and disable them
  	 * (they will be reenabled in change_speed())
  	 */
  
  	uart->ustcnt = USTCNT_UEN;
  	uart->ustcnt = USTCNT_UEN | USTCNT_RXEN | USTCNT_TXEN;
  	(void)uart->urx.w;
  
  	/*
  	 * Finally, enable sequencing and interrupts
  	 */
  #ifdef USE_INTS
  	uart->ustcnt = USTCNT_UEN | USTCNT_RXEN | 
                   USTCNT_RX_INTR_MASK | USTCNT_TX_INTR_MASK;
  #else
  	uart->ustcnt = USTCNT_UEN | USTCNT_RXEN | USTCNT_RX_INTR_MASK;
  #endif
  
  	if (tty)
  		clear_bit(TTY_IO_ERROR, &tty->flags);
  	info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
  
  	/*
  	 * and set the speed of the serial port
  	 */
  
  	change_speed(info, tty);
  
  	info->tport.flags |= ASYNC_INITIALIZED;
  	local_irq_restore(flags);
  	return 0;
  }
  
  /*
   * This routine will shutdown a serial port; interrupts are disabled, and
   * DTR is dropped if the hangup on close termio flag is on.
   */
  static void shutdown(struct m68k_serial *info, struct tty_struct *tty)
  {
  	m68328_uart *uart = &uart_addr[info->line];
  	unsigned long	flags;
  
  	uart->ustcnt = 0; /* All off! */
  	if (!(info->tport.flags & ASYNC_INITIALIZED))
  		return;
  
  	local_irq_save(flags);
  	
  	if (info->xmit_buf) {
  		free_page((unsigned long) info->xmit_buf);
  		info->xmit_buf = 0;
  	}
  
  	if (tty)
  		set_bit(TTY_IO_ERROR, &tty->flags);
  	
  	info->tport.flags &= ~ASYNC_INITIALIZED;
  	local_irq_restore(flags);
  }
  
  struct {
  	int divisor, prescale;
  }
  #ifndef CONFIG_M68VZ328
   hw_baud_table[18] = {
  	{0,0}, /* 0 */
  	{0,0}, /* 50 */
  	{0,0}, /* 75 */
  	{0,0}, /* 110 */
  	{0,0}, /* 134 */
  	{0,0}, /* 150 */
  	{0,0}, /* 200 */
  	{7,0x26}, /* 300 */
  	{6,0x26}, /* 600 */
  	{5,0x26}, /* 1200 */
  	{0,0}, /* 1800 */
  	{4,0x26}, /* 2400 */
  	{3,0x26}, /* 4800 */
  	{2,0x26}, /* 9600 */
  	{1,0x26}, /* 19200 */
  	{0,0x26}, /* 38400 */
  	{1,0x38}, /* 57600 */
  	{0,0x38}, /* 115200 */
  };
  #else
   hw_baud_table[18] = {
                   {0,0}, /* 0 */
                   {0,0}, /* 50 */
                   {0,0}, /* 75 */
                   {0,0}, /* 110 */
                   {0,0}, /* 134 */
                   {0,0}, /* 150 */
                   {0,0}, /* 200 */
                   {0,0}, /* 300 */
                   {7,0x26}, /* 600 */
                   {6,0x26}, /* 1200 */
                   {0,0}, /* 1800 */
                   {5,0x26}, /* 2400 */
                   {4,0x26}, /* 4800 */
                   {3,0x26}, /* 9600 */
                   {2,0x26}, /* 19200 */
                   {1,0x26}, /* 38400 */
                   {0,0x26}, /* 57600 */
                   {1,0x38}, /* 115200 */
  }; 
  #endif
  /* rate = 1036800 / ((65 - prescale) * (1<<divider)) */
  
  /*
   * This routine is called to set the UART divisor registers to match
   * the specified baud rate for a serial port.
   */
  static void change_speed(struct m68k_serial *info, struct tty_struct *tty)
  {
  	m68328_uart *uart = &uart_addr[info->line];
  	unsigned short port;
  	unsigned short ustcnt;
  	unsigned cflag;
  	int	i;
  
  	cflag = tty->termios.c_cflag;
  	if (!(port = info->port))
  		return;
  
  	ustcnt = uart->ustcnt;
  	uart->ustcnt = ustcnt & ~USTCNT_TXEN;
  
  	i = cflag & CBAUD;
          if (i & CBAUDEX) {
                  i = (i & ~CBAUDEX) + B38400;
          }
  
  	uart->ubaud = PUT_FIELD(UBAUD_DIVIDE,    hw_baud_table[i].divisor) | 
  		PUT_FIELD(UBAUD_PRESCALER, hw_baud_table[i].prescale);
  
  	ustcnt &= ~(USTCNT_PARITYEN | USTCNT_ODD_EVEN | USTCNT_STOP | USTCNT_8_7);
  	
  	if ((cflag & CSIZE) == CS8)
  		ustcnt |= USTCNT_8_7;
  		
  	if (cflag & CSTOPB)
  		ustcnt |= USTCNT_STOP;
  
  	if (cflag & PARENB)
  		ustcnt |= USTCNT_PARITYEN;
  	if (cflag & PARODD)
  		ustcnt |= USTCNT_ODD_EVEN;
  	
  #ifdef CONFIG_SERIAL_68328_RTS_CTS
  	if (cflag & CRTSCTS) {
  		uart->utx.w &= ~ UTX_NOCTS;
  	} else {
  		uart->utx.w |= UTX_NOCTS;
  	}
  #endif
  
  	ustcnt |= USTCNT_TXEN;
  	
  	uart->ustcnt = ustcnt;
  	return;
  }
  
  /*
   * Fair output driver allows a process to speak.
   */
  static void rs_fair_output(void)
  {
  	int left;		/* Output no more than that */
  	unsigned long flags;
  	struct m68k_serial *info = &m68k_soft[0];
  	char c;
  
  	if (info == 0) return;
  	if (info->xmit_buf == 0) return;
  
  	local_irq_save(flags);
  	left = info->xmit_cnt;
  	while (left != 0) {
  		c = info->xmit_buf[info->xmit_tail];
  		info->xmit_tail = (info->xmit_tail+1) & (SERIAL_XMIT_SIZE-1);
  		info->xmit_cnt--;
  		local_irq_restore(flags);
  
  		rs_put_char(c);
  
  		local_irq_save(flags);
  		left = min(info->xmit_cnt, left-1);
  	}
  
  	/* Last character is being transmitted now (hopefully). */
  	udelay(5);
  
  	local_irq_restore(flags);
  	return;
  }
  
  /*
   * m68k_console_print is registered for printk.
   */
  void console_print_68328(const char *p)
  {
  	char c;
  	
  	while((c=*(p++)) != 0) {
  		if(c == '\n')
  			rs_put_char('\r');
  		rs_put_char(c);
  	}
  
  	/* Comment this if you want to have a strict interrupt-driven output */
  	rs_fair_output();
  
  	return;
  }
  
  static void rs_set_ldisc(struct tty_struct *tty)
  {
  	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
  
  	if (serial_paranoia_check(info, tty->name, "rs_set_ldisc"))
  		return;
  
  	info->is_cons = (tty->termios.c_line == N_TTY);
  	
  	printk("ttyS%d console mode %s\n", info->line, info->is_cons ? "on" : "off");
  }
  
  static void rs_flush_chars(struct tty_struct *tty)
  {
  	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
  	m68328_uart *uart = &uart_addr[info->line];
  	unsigned long flags;
  
  	if (serial_paranoia_check(info, tty->name, "rs_flush_chars"))
  		return;
  #ifndef USE_INTS
  	for(;;) {
  #endif
  
  	/* Enable transmitter */
  	local_irq_save(flags);
  
  	if (info->xmit_cnt <= 0 || tty->stopped || tty->hw_stopped ||
  			!info->xmit_buf) {
  		local_irq_restore(flags);
  		return;
  	}
  
  #ifdef USE_INTS
  	uart->ustcnt |= USTCNT_TXEN | USTCNT_TX_INTR_MASK;
  #else
  	uart->ustcnt |= USTCNT_TXEN;
  #endif
  
  #ifdef USE_INTS
  	if (uart->utx.w & UTX_TX_AVAIL) {
  #else
  	if (1) {
  #endif
  		/* Send char */
  		uart->utx.b.txdata = info->xmit_buf[info->xmit_tail++];
  		info->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
  		info->xmit_cnt--;
  	}
  
  #ifndef USE_INTS
  	while (!(uart->utx.w & UTX_TX_AVAIL)) udelay(5);
  	}
  #endif
  	local_irq_restore(flags);
  }
  
  extern void console_printn(const char * b, int count);
  
  static int rs_write(struct tty_struct * tty,
  		    const unsigned char *buf, int count)
  {
  	int	c, total = 0;
  	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
  	m68328_uart *uart = &uart_addr[info->line];
  	unsigned long flags;
  
  	if (serial_paranoia_check(info, tty->name, "rs_write"))
  		return 0;
  
  	if (!tty || !info->xmit_buf)
  		return 0;
  
  	local_save_flags(flags);
  	while (1) {
  		local_irq_disable();		
  		c = min_t(int, count, min(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
  				   SERIAL_XMIT_SIZE - info->xmit_head));
  		local_irq_restore(flags);
  
  		if (c <= 0)
  			break;
  
  		memcpy(info->xmit_buf + info->xmit_head, buf, c);
  
  		local_irq_disable();
  		info->xmit_head = (info->xmit_head + c) & (SERIAL_XMIT_SIZE-1);
  		info->xmit_cnt += c;
  		local_irq_restore(flags);
  		buf += c;
  		count -= c;
  		total += c;
  	}
  
  	if (info->xmit_cnt && !tty->stopped && !tty->hw_stopped) {
  		/* Enable transmitter */
  		local_irq_disable();		
  #ifndef USE_INTS
  		while(info->xmit_cnt) {
  #endif
  
  		uart->ustcnt |= USTCNT_TXEN;
  #ifdef USE_INTS
  		uart->ustcnt |= USTCNT_TX_INTR_MASK;
  #else
  		while (!(uart->utx.w & UTX_TX_AVAIL)) udelay(5);
  #endif
  		if (uart->utx.w & UTX_TX_AVAIL) {
  			uart->utx.b.txdata = info->xmit_buf[info->xmit_tail++];
  			info->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
  			info->xmit_cnt--;
  		}
  
  #ifndef USE_INTS
  		}
  #endif
  		local_irq_restore(flags);
  	}
  
  	return total;
  }
  
  static int rs_write_room(struct tty_struct *tty)
  {
  	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
  	int	ret;
  				
  	if (serial_paranoia_check(info, tty->name, "rs_write_room"))
  		return 0;
  	ret = SERIAL_XMIT_SIZE - info->xmit_cnt - 1;
  	if (ret < 0)
  		ret = 0;
  	return ret;
  }
  
  static int rs_chars_in_buffer(struct tty_struct *tty)
  {
  	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
  				
  	if (serial_paranoia_check(info, tty->name, "rs_chars_in_buffer"))
  		return 0;
  	return info->xmit_cnt;
  }
  
  static void rs_flush_buffer(struct tty_struct *tty)
  {
  	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
  	unsigned long flags;
  				
  	if (serial_paranoia_check(info, tty->name, "rs_flush_buffer"))
  		return;
  	local_irq_save(flags);
  	info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
  	local_irq_restore(flags);
  	tty_wakeup(tty);
  }
  
  /*
   * ------------------------------------------------------------
   * rs_throttle()
   * 
   * This routine is called by the upper-layer tty layer to signal that
   * incoming characters should be throttled.
   * ------------------------------------------------------------
   */
  static void rs_throttle(struct tty_struct * tty)
  {
  	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
  
  	if (serial_paranoia_check(info, tty->name, "rs_throttle"))
  		return;
  	
  	if (I_IXOFF(tty))
  		info->x_char = STOP_CHAR(tty);
  
  	/* Turn off RTS line (do this atomic) */
  }
  
  static void rs_unthrottle(struct tty_struct * tty)
  {
  	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
  
  	if (serial_paranoia_check(info, tty->name, "rs_unthrottle"))
  		return;
  	
  	if (I_IXOFF(tty)) {
  		if (info->x_char)
  			info->x_char = 0;
  		else
  			info->x_char = START_CHAR(tty);
  	}
  
  	/* Assert RTS line (do this atomic) */
  }
  
  /*
   * ------------------------------------------------------------
   * rs_ioctl() and friends
   * ------------------------------------------------------------
   */
  
  static int get_serial_info(struct m68k_serial * info,
  			   struct serial_struct * retinfo)
  {
  	struct serial_struct tmp;
    
  	if (!retinfo)
  		return -EFAULT;
  	memset(&tmp, 0, sizeof(tmp));
  	tmp.type = info->type;
  	tmp.line = info->line;
  	tmp.port = info->port;
  	tmp.irq = info->irq;
  	tmp.flags = info->tport.flags;
  	tmp.baud_base = info->baud_base;
  	tmp.close_delay = info->tport.close_delay;
  	tmp.closing_wait = info->tport.closing_wait;
  	tmp.custom_divisor = info->custom_divisor;
  	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
  		return -EFAULT;
  
  	return 0;
  }
  
  static int set_serial_info(struct m68k_serial *info, struct tty_struct *tty,
  			   struct serial_struct * new_info)
  {
  	struct tty_port *port = &info->tport;
  	struct serial_struct new_serial;
  	struct m68k_serial old_info;
  	int 			retval = 0;
  
  	if (!new_info)
  		return -EFAULT;
  	if (copy_from_user(&new_serial, new_info, sizeof(new_serial)))
  		return -EFAULT;
  	old_info = *info;
  
  	if (!capable(CAP_SYS_ADMIN)) {
  		if ((new_serial.baud_base != info->baud_base) ||
  		    (new_serial.type != info->type) ||
  		    (new_serial.close_delay != port->close_delay) ||
  		    ((new_serial.flags & ~ASYNC_USR_MASK) !=
  		     (port->flags & ~ASYNC_USR_MASK)))
  			return -EPERM;
  		port->flags = ((port->flags & ~ASYNC_USR_MASK) |
  			       (new_serial.flags & ASYNC_USR_MASK));
  		info->custom_divisor = new_serial.custom_divisor;
  		goto check_and_exit;
  	}
  
  	if (port->count > 1)
  		return -EBUSY;
  
  	/*
  	 * OK, past this point, all the error checking has been done.
  	 * At this point, we start making changes.....
  	 */
  
  	info->baud_base = new_serial.baud_base;
  	port->flags = ((port->flags & ~ASYNC_FLAGS) |
  			(new_serial.flags & ASYNC_FLAGS));
  	info->type = new_serial.type;
  	port->close_delay = new_serial.close_delay;
  	port->closing_wait = new_serial.closing_wait;
  
  check_and_exit:
  	retval = startup(info, tty);
  	return retval;
  }
  
  /*
   * get_lsr_info - get line status register info
   *
   * Purpose: Let user call ioctl() to get info when the UART physically
   * 	    is emptied.  On bus types like RS485, the transmitter must
   * 	    release the bus after transmitting. This must be done when
   * 	    the transmit shift register is empty, not be done when the
   * 	    transmit holding register is empty.  This functionality
   * 	    allows an RS485 driver to be written in user space. 
   */
  static int get_lsr_info(struct m68k_serial * info, unsigned int *value)
  {
  #ifdef CONFIG_SERIAL_68328_RTS_CTS
  	m68328_uart *uart = &uart_addr[info->line];
  #endif
  	unsigned char status;
  	unsigned long flags;
  
  	local_irq_save(flags);
  #ifdef CONFIG_SERIAL_68328_RTS_CTS
  	status = (uart->utx.w & UTX_CTS_STAT) ? 1 : 0;
  #else
  	status = 0;
  #endif
  	local_irq_restore(flags);
  	return put_user(status, value);
  }
  
  /*
   * This routine sends a break character out the serial port.
   */
  static void send_break(struct m68k_serial * info, unsigned int duration)
  {
  	m68328_uart *uart = &uart_addr[info->line];
          unsigned long flags;
          if (!info->port)
                  return;
          local_irq_save(flags);
  #ifdef USE_INTS	
  	uart->utx.w |= UTX_SEND_BREAK;
  	msleep_interruptible(duration);
  	uart->utx.w &= ~UTX_SEND_BREAK;
  #endif		
          local_irq_restore(flags);
  }
  
  static int rs_ioctl(struct tty_struct *tty,
  		    unsigned int cmd, unsigned long arg)
  {
  	struct m68k_serial * info = (struct m68k_serial *)tty->driver_data;
  	int retval;
  
  	if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
  		return -ENODEV;
  
  	if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
  	    (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGWILD)  &&
  	    (cmd != TIOCSERSWILD) && (cmd != TIOCSERGSTRUCT)) {
  		if (tty->flags & (1 << TTY_IO_ERROR))
  		    return -EIO;
  	}
  	
  	switch (cmd) {
  		case TCSBRK:	/* SVID version: non-zero arg --> no break */
  			retval = tty_check_change(tty);
  			if (retval)
  				return retval;
  			tty_wait_until_sent(tty, 0);
  			if (!arg)
  				send_break(info, 250);	/* 1/4 second */
  			return 0;
  		case TCSBRKP:	/* support for POSIX tcsendbreak() */
  			retval = tty_check_change(tty);
  			if (retval)
  				return retval;
  			tty_wait_until_sent(tty, 0);
  			send_break(info, arg ? arg*(100) : 250);
  			return 0;
  		case TIOCGSERIAL:
  			return get_serial_info(info,
  				       (struct serial_struct *) arg);
  		case TIOCSSERIAL:
  			return set_serial_info(info, tty,
  					       (struct serial_struct *) arg);
  		case TIOCSERGETLSR: /* Get line status register */
  			return get_lsr_info(info, (unsigned int *) arg);
  		case TIOCSERGSTRUCT:
  			if (copy_to_user((struct m68k_serial *) arg,
  				    info, sizeof(struct m68k_serial)))
  				return -EFAULT;
  			return 0;
  		default:
  			return -ENOIOCTLCMD;
  		}
  	return 0;
  }
  
  static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
  {
  	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
  
  	change_speed(info, tty);
  
  	if ((old_termios->c_cflag & CRTSCTS) &&
  	    !(tty->termios.c_cflag & CRTSCTS)) {
  		tty->hw_stopped = 0;
  		rs_start(tty);
  	}
  	
  }
  
  /*
   * ------------------------------------------------------------
   * rs_close()
   * 
   * This routine is called when the serial port gets closed.  First, we
   * wait for the last remaining data to be sent.  Then, we unlink its
   * S structure from the interrupt chain if necessary, and we free
   * that IRQ if nothing is left in the chain.
   * ------------------------------------------------------------
   */
  static void rs_close(struct tty_struct *tty, struct file * filp)
  {
  	struct m68k_serial * info = (struct m68k_serial *)tty->driver_data;
  	struct tty_port *port = &info->tport;
  	m68328_uart *uart = &uart_addr[info->line];
  	unsigned long flags;
  
  	if (!info || serial_paranoia_check(info, tty->name, "rs_close"))
  		return;
  	
  	local_irq_save(flags);
  	
  	if (tty_hung_up_p(filp)) {
  		local_irq_restore(flags);
  		return;
  	}
  	
  	if ((tty->count == 1) && (port->count != 1)) {
  		/*
  		 * Uh, oh.  tty->count is 1, which means that the tty
  		 * structure will be freed.  Info->count should always
  		 * be one in these conditions.  If it's greater than
  		 * one, we've got real problems, since it means the
  		 * serial port won't be shutdown.
  		 */
  		printk("rs_close: bad serial port count; tty->count is 1, "
  		       "port->count is %d\n", port->count);
  		port->count = 1;
  	}
  	if (--port->count < 0) {
  		printk("rs_close: bad serial port count for ttyS%d: %d\n",
  		       info->line, port->count);
  		port->count = 0;
  	}
  	if (port->count) {
  		local_irq_restore(flags);
  		return;
  	}
  	port->flags |= ASYNC_CLOSING;
  	/*
  	 * Now we wait for the transmit buffer to clear; and we notify 
  	 * the line discipline to only process XON/XOFF characters.
  	 */
  	tty->closing = 1;
  	if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
  		tty_wait_until_sent(tty, port->closing_wait);
  	/*
  	 * At this point we stop accepting input.  To do this, we
  	 * disable the receive line status interrupts, and tell the
  	 * interrupt driver to stop checking the data ready bit in the
  	 * line status register.
  	 */
  
  	uart->ustcnt &= ~USTCNT_RXEN;
  	uart->ustcnt &= ~(USTCNT_RXEN | USTCNT_RX_INTR_MASK);
  
  	shutdown(info, tty);
  	rs_flush_buffer(tty);
  		
  	tty_ldisc_flush(tty);
  	tty->closing = 0;
  	tty_port_tty_set(&info->tport, NULL);
  #warning "This is not and has never been valid so fix it"	
  #if 0
  	if (tty->ldisc.num != ldiscs[N_TTY].num) {
  		if (tty->ldisc.close)
  			(tty->ldisc.close)(tty);
  		tty->ldisc = ldiscs[N_TTY];
  		tty->termios.c_line = N_TTY;
  		if (tty->ldisc.open)
  			(tty->ldisc.open)(tty);
  	}
  #endif	
  	if (port->blocked_open) {
  		if (port->close_delay)
  			msleep_interruptible(jiffies_to_msecs(port->close_delay));
  		wake_up_interruptible(&port->open_wait);
  	}
  	port->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
  	wake_up_interruptible(&port->close_wait);
  	local_irq_restore(flags);
  }
  
  /*
   * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
   */
  void rs_hangup(struct tty_struct *tty)
  {
  	struct m68k_serial * info = (struct m68k_serial *)tty->driver_data;
  	
  	if (serial_paranoia_check(info, tty->name, "rs_hangup"))
  		return;
  	
  	rs_flush_buffer(tty);
  	shutdown(info, tty);
  	info->tport.count = 0;
  	info->tport.flags &= ~ASYNC_NORMAL_ACTIVE;
  	tty_port_tty_set(&info->tport, NULL);
  	wake_up_interruptible(&info->tport.open_wait);
  }
  
  /*
   * This routine is called whenever a serial port is opened.  It
   * enables interrupts for a serial port, linking in its S structure into
   * the IRQ chain.   It also performs the serial-specific
   * initialization for the tty structure.
   */
  int rs_open(struct tty_struct *tty, struct file * filp)
  {
  	struct m68k_serial	*info;
  	int retval;
  
  	info = &m68k_soft[tty->index];
  
  	if (serial_paranoia_check(info, tty->name, "rs_open"))
  		return -ENODEV;
  
  	info->tport.count++;
  	tty->driver_data = info;
  	tty_port_tty_set(&info->tport, tty);
  
  	/*
  	 * Start up serial port
  	 */
  	retval = startup(info, tty);
  	if (retval)
  		return retval;
  
  	return tty_port_block_til_ready(&info->tport, tty, filp);
  }
  
  /* Finally, routines used to initialize the serial driver. */
  
  static void show_serial_version(void)
  {
  	printk("MC68328 serial driver version 1.00\n");
  }
  
  static const struct tty_operations rs_ops = {
  	.open = rs_open,
  	.close = rs_close,
  	.write = rs_write,
  	.flush_chars = rs_flush_chars,
  	.write_room = rs_write_room,
  	.chars_in_buffer = rs_chars_in_buffer,
  	.flush_buffer = rs_flush_buffer,
  	.ioctl = rs_ioctl,
  	.throttle = rs_throttle,
  	.unthrottle = rs_unthrottle,
  	.set_termios = rs_set_termios,
  	.stop = rs_stop,
  	.start = rs_start,
  	.hangup = rs_hangup,
  	.set_ldisc = rs_set_ldisc,
  };
  
  static const struct tty_port_operations rs_port_ops = {
  };
  
  /* rs_init inits the driver */
  static int __init
  rs68328_init(void)
  {
  	unsigned long flags;
  	int i;
  	struct m68k_serial *info;
  
  	serial_driver = alloc_tty_driver(NR_PORTS);
  	if (!serial_driver)
  		return -ENOMEM;
  
  	show_serial_version();
  
  	/* Initialize the tty_driver structure */
  	/* SPARC: Not all of this is exactly right for us. */
  	
  	serial_driver->name = "ttyS";
  	serial_driver->major = TTY_MAJOR;
  	serial_driver->minor_start = 64;
  	serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
  	serial_driver->subtype = SERIAL_TYPE_NORMAL;
  	serial_driver->init_termios = tty_std_termios;
  	serial_driver->init_termios.c_cflag = 
  			m68328_console_cbaud | CS8 | CREAD | HUPCL | CLOCAL;
  	serial_driver->flags = TTY_DRIVER_REAL_RAW;
  	tty_set_operations(serial_driver, &rs_ops);
  
  	local_irq_save(flags);
  
  	for(i=0;i<NR_PORTS;i++) {
  
  	    info = &m68k_soft[i];
  	    tty_port_init(&info->tport);
  	    info->tport.ops = &rs_port_ops;
  	    info->magic = SERIAL_MAGIC;
  	    info->port = (int) &uart_addr[i];
  	    info->irq = uart_irqs[i];
  	    info->custom_divisor = 16;
  	    info->x_char = 0;
  	    info->line = i;
  	    info->is_cons = 1; /* Means shortcuts work */
  	    
  	    printk("%s%d at 0x%08x (irq = %d)", serial_driver->name, info->line, 
  		   info->port, info->irq);
  	    printk(" is a builtin MC68328 UART\n");
  	    
  #ifdef CONFIG_M68VZ328
  		if (i > 0 )
  			PJSEL &= 0xCF;  /* PSW enable second port output */
  #endif
  
  	    if (request_irq(uart_irqs[i],
  			    rs_interrupt,
  			    0,
  			    "M68328_UART", info))
                  panic("Unable to attach 68328 serial interrupt\n");
  
  	    tty_port_link_device(&info->tport, serial_driver, i);
  	}
  	local_irq_restore(flags);
  
  	if (tty_register_driver(serial_driver)) {
  		put_tty_driver(serial_driver);
  		printk(KERN_ERR "Couldn't register serial driver\n");
  		return -ENOMEM;
  	}
  
  	return 0;
  }
  
  module_init(rs68328_init);
  
  
  
  static void m68328_set_baud(void)
  {
  	unsigned short ustcnt;
  	int	i;
  
  	ustcnt = USTCNT;
  	USTCNT = ustcnt & ~USTCNT_TXEN;
  
  again:
  	for (i = 0; i < ARRAY_SIZE(baud_table); i++)
  		if (baud_table[i] == m68328_console_baud)
  			break;
  	if (i >= ARRAY_SIZE(baud_table)) {
  		m68328_console_baud = 9600;
  		goto again;
  	}
  
  	UBAUD = PUT_FIELD(UBAUD_DIVIDE,    hw_baud_table[i].divisor) | 
  		PUT_FIELD(UBAUD_PRESCALER, hw_baud_table[i].prescale);
  	ustcnt &= ~(USTCNT_PARITYEN | USTCNT_ODD_EVEN | USTCNT_STOP | USTCNT_8_7);
  	ustcnt |= USTCNT_8_7;
  	ustcnt |= USTCNT_TXEN;
  	USTCNT = ustcnt;
  	m68328_console_initted = 1;
  	return;
  }
  
  
  int m68328_console_setup(struct console *cp, char *arg)
  {
  	int		i, n = CONSOLE_BAUD_RATE;
  
  	if (!cp)
  		return(-1);
  
  	if (arg)
  		n = simple_strtoul(arg,NULL,0);
  
  	for (i = 0; i < ARRAY_SIZE(baud_table); i++)
  		if (baud_table[i] == n)
  			break;
  	if (i < ARRAY_SIZE(baud_table)) {
  		m68328_console_baud = n;
  		m68328_console_cbaud = 0;
  		if (i > 15) {
  			m68328_console_cbaud |= CBAUDEX;
  			i -= 15;
  		}
  		m68328_console_cbaud |= i;
  	}
  
  	m68328_set_baud(); /* make sure baud rate changes */
  	return(0);
  }
  
  
  static struct tty_driver *m68328_console_device(struct console *c, int *index)
  {
  	*index = c->index;
  	return serial_driver;
  }
  
  
  void m68328_console_write (struct console *co, const char *str,
  			   unsigned int count)
  {
  	if (!m68328_console_initted)
  		m68328_set_baud();
      while (count--) {
          if (*str == '\n')
             rs_put_char('\r');
          rs_put_char( *str++ );
      }
  }
  
  
  static struct console m68328_driver = {
  	.name		= "ttyS",
  	.write		= m68328_console_write,
  	.device		= m68328_console_device,
  	.setup		= m68328_console_setup,
  	.flags		= CON_PRINTBUFFER,
  	.index		= -1,
  };
  
  
  static int __init m68328_console_init(void)
  {
  	register_console(&m68328_driver);
  	return 0;
  }
  
  console_initcall(m68328_console_init);
  