68328serial.c

这是一个SIGMA方案的PMP播放器的UCLINUX程序,可播放DVD,VCD,CD MP3...有很好的参考价值.

	m68328_uart *uart = &uart_addr[info->line];
	unsigned long	flags;

	uart->ustcnt = 0; /* All off! */
	if (!(info->flags & S_INITIALIZED))
		return;

	save_flags(flags); cli(); /* Disable interrupts */
	
	if (info->xmit_buf) {
		free_page((unsigned long) info->xmit_buf);
		info->xmit_buf = 0;
	}

	if (info->tty)
		set_bit(TTY_IO_ERROR, &info->tty->flags);
	
	info->flags &= ~S_INITIALIZED;
	restore_flags(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)
{
	m68328_uart *uart = &uart_addr[info->line];
	unsigned short port;
	unsigned short ustcnt;
	unsigned cflag;
	int	i;

	if (!info->tty || !info->tty->termios)
		return;
	cflag = info->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;
        }

	info->baud = baud_table[i];
	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_68328_SERIAL_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;

	save_flags(flags);  cli();
	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--;
		restore_flags(flags);

		rs_put_char(c);

		save_flags(flags);  cli();
		left = MIN(info->xmit_cnt, left-1);
	}

	/* Last character is being transmitted now (hopefully). */
	udelay(5);

	restore_flags(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->device, "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->device, "rs_flush_chars"))
		return;
#ifndef USE_INTS
	for(;;) {
#endif
	if (info->xmit_cnt <= 0 || tty->stopped || tty->hw_stopped ||
	    !info->xmit_buf)
		return;

	/* Enable transmitter */
	save_flags(flags); cli();

#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
	restore_flags(flags);
}

extern void console_printn(const char * b, int count);

static int rs_write(struct tty_struct * tty, int from_user,
		    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->device, "rs_write"))
		return 0;

	if (!tty || !info->xmit_buf)
		return 0;

	save_flags(flags);
	while (1) {
		cli();		
		c = MIN(count, MIN(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
				   SERIAL_XMIT_SIZE - info->xmit_head));
		if (c <= 0)
			break;

		if (from_user) {
			down(&tmp_buf_sem);
			copy_from_user(tmp_buf, buf, c);
			c = MIN(c, MIN(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
				       SERIAL_XMIT_SIZE - info->xmit_head));
			memcpy(info->xmit_buf + info->xmit_head, tmp_buf, c);
			up(&tmp_buf_sem);
		} else
			memcpy(info->xmit_buf + info->xmit_head, buf, c);
		info->xmit_head = (info->xmit_head + c) & (SERIAL_XMIT_SIZE-1);
		info->xmit_cnt += c;
		restore_flags(flags);
		buf += c;
		count -= c;
		total += c;
	}

	if (info->xmit_cnt && !tty->stopped && !tty->hw_stopped) {
		/* Enable transmitter */
		cli();		
#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
		restore_flags(flags);
	}
	restore_flags(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->device, "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->device, "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;
				
	if (serial_paranoia_check(info, tty->device, "rs_flush_buffer"))
		return;
	cli();
	info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
	sti();
	wake_up_interruptible(&tty->write_wait);
	if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
	    tty->ldisc.write_wakeup)
		(tty->ldisc.write_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->device, "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->device, "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->flags;
	tmp.baud_base = info->baud_base;
	tmp.close_delay = info->close_delay;
	tmp.closing_wait = info->closing_wait;
	tmp.custom_divisor = info->custom_divisor;
	copy_to_user(retinfo,&tmp,sizeof(*retinfo));
	return 0;
}

static int set_serial_info(struct m68k_serial * info,
			   struct serial_struct * new_info)
{
	struct serial_struct new_serial;
	struct m68k_serial old_info;
	int 			retval = 0;

	if (!new_info)
		return -EFAULT;
	copy_from_user(&new_serial,new_info,sizeof(new_serial));
	old_info = *info;

	if (!suser()) {
		if ((new_serial.baud_base != info->baud_base) ||
		    (new_serial.type != info->type) ||
		    (new_serial.close_delay != info->close_delay) ||
		    ((new_serial.flags & ~S_USR_MASK) !=
		     (info->flags & ~S_USR_MASK)))
			return -EPERM;
		info->flags = ((info->flags & ~S_USR_MASK) |
			       (new_serial.flags & S_USR_MASK));
		info->custom_divisor = new_serial.custom_divisor;
		goto check_and_exit;
	}

	if (info->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;
	info->flags = ((info->flags & ~S_FLAGS) |
			(new_serial.flags & S_FLAGS));
	info->type = new_serial.type;
	info->close_delay = new_serial.close_delay;
	info->closing_wait = new_serial.closing_wait;

check_and_exit:
	retval = startup(info);
	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_68328_SERIAL_RTS_CTS
	m68328_uart *uart = &uart_addr[info->line];
#endif
	unsigned char status;

	cli();
#ifdef CONFIG_68328_SERIAL_RTS_CTS
	status = (uart->utx.w & UTX_CTS_STAT) ? 1 : 0;
#else
	status = 0;
#endif
	sti();
	put_user(status,value);
	return 0;
}

/*
 * This routine sends a break character out the serial port.
 */
static void send_break(	struct m68k_serial * info, int duration)
{
	m68328_uart *uart = &uart_addr[info->line];
        unsigned long flags;
        if (!info->port)
                return;
        current->state = TASK_INTERRUPTIBLE;
        save_flags(flags);
        cli();
#ifdef USE_INTS	
	uart->utx.w |= UTX_SEND_BREAK;
        schedule_timeout(duration);
	uart->utx.w &= ~UTX_SEND_BREAK;
#endif		
        restore_flags(flags);
}

static int rs_ioctl(struct tty_struct *tty, struct file * file,
		    unsigned int cmd, unsigned long arg)
{
	int error;
	struct m68k_serial * info = (struct m68k_serial *)tty->driver_data;
	int retval;

	if (serial_paranoia_check(info, tty->device, "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, HZ/4);	/* 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*(HZ/10) : HZ/4);
			return 0;
		case TIOCGSOFTCAR:
			error = verify_area(VERIFY_WRITE, (void *) arg,sizeof(long));
			if (error)
				return error;
			put_user(C_CLOCAL(tty) ? 1 : 0,
				    (unsigned long *) arg);
			return 0;
		case TIOCSSOFTCAR:
			get_user(arg, (unsigned long *) arg);
			tty->termios->c_cflag =
				((tty->termios->c_cflag & ~CLOCAL) |
				 (arg ? CLOCAL : 0));
			return 0;
		case TIOCGSERIAL:
			error = verify_area(VERIFY_WRITE, (void *) arg,
						sizeof(struct serial_struct));
			if (error)
				return error;
			return get_serial_info(info,
					       (struct serial_struct *) arg);
		case TIOCSSERIAL:
			return set_serial_info(info,
					       (struct serial_struct *) arg);
		case TIOCSERGETLSR: /* Get line status register */
			error = verify_area(VERIFY_WRITE, (void *) arg,
				sizeof(unsigned int));