68328serial.c

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/* 68328serial.c: Serial port driver for 68328 microcontroller
 *
 * Copyright (C) 1995       David S. Miller    <[email protected]>
 * Copyright (C) 1998       Kenneth Albanowski <[email protected]>
 * Copyright (C) 1998, 1999 D. Jeff Dionne     <[email protected]>
 * Copyright (C) 1999       Vladimir Gurevich  <[email protected]>
 * Copyright (C) 2002-2003  David McCullough   <[email protected]>
 * Copyright (C) 2002       Greg Ungerer       <[email protected]>
 *
 * VZ Support/Fixes             Evan Stawnyczy <[email protected]>
 * Multiple UART support        Daniel Potts <[email protected]>
 * Power management support     Daniel Potts <[email protected]>
 * 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);