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.

			if (error)
				return error;
			else
			    return get_lsr_info(info, (unsigned int *) arg);

		case TIOCSERGSTRUCT:
			error = verify_area(VERIFY_WRITE, (void *) arg,
						sizeof(struct m68k_serial));
			if (error)
				return error;
			copy_to_user((struct m68k_serial *) arg,
				    info, sizeof(struct m68k_serial));
			return 0;
			
		default:
			return -ENOIOCTLCMD;
		}
	return 0;
}

static void rs_set_termios(struct tty_struct *tty, struct termios *old_termios)
{
	struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;

	if (tty->termios->c_cflag == old_termios->c_cflag)
		return;

	change_speed(info);

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

	if (!info || serial_paranoia_check(info, tty->device, "rs_close"))
		return;
	
	save_flags(flags); cli();
	
	if (tty_hung_up_p(filp)) {
		restore_flags(flags);
		return;
	}
	
	if ((tty->count == 1) && (info->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, "
		       "info->count is %d\n", info->count);
		info->count = 1;
	}
	if (--info->count < 0) {
		printk("rs_close: bad serial port count for ttyS%d: %d\n",
		       info->line, info->count);
		info->count = 0;
	}
	if (info->count) {
		restore_flags(flags);
		return;
	}
	info->flags |= S_CLOSING;
	/*
	 * Save the termios structure, since this port may have
	 * separate termios for callout and dialin.
	 */
	if (info->flags & S_NORMAL_ACTIVE)
		info->normal_termios = *tty->termios;
	if (info->flags & S_CALLOUT_ACTIVE)
		info->callout_termios = *tty->termios;
	/*
	 * 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 (info->closing_wait != S_CLOSING_WAIT_NONE)
		tty_wait_until_sent(tty, info->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);
	if (tty->driver.flush_buffer)
		tty->driver.flush_buffer(tty);
	if (tty->ldisc.flush_buffer)
		tty->ldisc.flush_buffer(tty);
	tty->closing = 0;
	info->event = 0;
	info->tty = 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);
	}
	if (info->blocked_open) {
		if (info->close_delay) {
			current->state = TASK_INTERRUPTIBLE;
			schedule_timeout(info->close_delay);
		}
		wake_up_interruptible(&info->open_wait);
	}
	info->flags &= ~(S_NORMAL_ACTIVE|S_CALLOUT_ACTIVE|
			 S_CLOSING);
	wake_up_interruptible(&info->close_wait);
	restore_flags(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->device, "rs_hangup"))
		return;
	
	rs_flush_buffer(tty);
	shutdown(info);
	info->event = 0;
	info->count = 0;
	info->flags &= ~(S_NORMAL_ACTIVE|S_CALLOUT_ACTIVE);
	info->tty = 0;
	wake_up_interruptible(&info->open_wait);
}

/*
 * ------------------------------------------------------------
 * rs_open() and friends
 * ------------------------------------------------------------
 */
static int block_til_ready(struct tty_struct *tty, struct file * filp,
			   struct m68k_serial *info)
{
	DECLARE_WAITQUEUE(wait, current);
	int		retval;
	int		do_clocal = 0;

	/*
	 * If the device is in the middle of being closed, then block
	 * until it's done, and then try again.
	 */
	if (info->flags & S_CLOSING) {
		interruptible_sleep_on(&info->close_wait);
#ifdef SERIAL_DO_RESTART
		if (info->flags & S_HUP_NOTIFY)
			return -EAGAIN;
		else
			return -ERESTARTSYS;
#else
		return -EAGAIN;
#endif
	}

	/*
	 * If this is a callout device, then just make sure the normal
	 * device isn't being used.
	 */
	if (tty->driver.subtype == SERIAL_TYPE_CALLOUT) {
		if (info->flags & S_NORMAL_ACTIVE)
			return -EBUSY;
		if ((info->flags & S_CALLOUT_ACTIVE) &&
		    (info->flags & S_SESSION_LOCKOUT) &&
		    (info->session != current->session))
		    return -EBUSY;
		if ((info->flags & S_CALLOUT_ACTIVE) &&
		    (info->flags & S_PGRP_LOCKOUT) &&
		    (info->pgrp != current->pgrp))
		    return -EBUSY;
		info->flags |= S_CALLOUT_ACTIVE;
		return 0;
	}
	
	/*
	 * If non-blocking mode is set, or the port is not enabled,
	 * then make the check up front and then exit.
	 */
	if ((filp->f_flags & O_NONBLOCK) ||
	    (tty->flags & (1 << TTY_IO_ERROR))) {
		if (info->flags & S_CALLOUT_ACTIVE)
			return -EBUSY;
		info->flags |= S_NORMAL_ACTIVE;
		return 0;
	}

	if (info->flags & S_CALLOUT_ACTIVE) {
		if (info->normal_termios.c_cflag & CLOCAL)
			do_clocal = 1;
	} else {
		if (tty->termios->c_cflag & CLOCAL)
			do_clocal = 1;
	}
	
	/*
	 * Block waiting for the carrier detect and the line to become
	 * free (i.e., not in use by the callout).  While we are in
	 * this loop, info->count is dropped by one, so that
	 * rs_close() knows when to free things.  We restore it upon
	 * exit, either normal or abnormal.
	 */
	retval = 0;
	add_wait_queue(&info->open_wait, &wait);

	info->count--;
	info->blocked_open++;
	while (1) {
		cli();
		if (!(info->flags & S_CALLOUT_ACTIVE))
			m68k_rtsdtr(info, 1);
		sti();
		current->state = TASK_INTERRUPTIBLE;
		if (tty_hung_up_p(filp) ||
		    !(info->flags & S_INITIALIZED)) {
#ifdef SERIAL_DO_RESTART
			if (info->flags & S_HUP_NOTIFY)
				retval = -EAGAIN;
			else
				retval = -ERESTARTSYS;	
#else
			retval = -EAGAIN;
#endif
			break;
		}
		if (!(info->flags & S_CALLOUT_ACTIVE) &&
		    !(info->flags & S_CLOSING) && do_clocal)
			break;
                if (signal_pending(current)) {
			retval = -ERESTARTSYS;
			break;
		}
		schedule();
	}
	current->state = TASK_RUNNING;
	remove_wait_queue(&info->open_wait, &wait);
	if (!tty_hung_up_p(filp))
		info->count++;
	info->blocked_open--;

	if (retval)
		return retval;
	info->flags |= S_NORMAL_ACTIVE;
	return 0;
}	

/*
 * 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, line;

	line = MINOR(tty->device) - tty->driver.minor_start;
	
	if (line >= NR_PORTS || line < 0) /* we have exactly one */
		return -ENODEV;

	info = &m68k_soft[line];

	if (serial_paranoia_check(info, tty->device, "rs_open"))
		return -ENODEV;

	info->count++;
	tty->driver_data = info;
	info->tty = tty;

	/*
	 * Start up serial port
	 */
	retval = startup(info);
	if (retval)
		return retval;

	retval = block_til_ready(tty, filp, info);
	if (retval) {
		return retval;
	}

	if ((info->count == 1) && (info->flags & S_SPLIT_TERMIOS)) {
		if (tty->driver.subtype == SERIAL_TYPE_NORMAL)
			*tty->termios = info->normal_termios;
		else 
			*tty->termios = info->callout_termios;
		change_speed(info);
	}

	info->session = current->session;
	info->pgrp = current->pgrp;

	return 0;
}

/* Finally, routines used to initialize the serial driver. */

static void show_serial_version(void)
{
	printk("MC68328 serial driver version 1.00\n");
}

volatile int test_done;

/* rs_init inits the driver */
static int __init
rs68328_init(void)
{
	int flags, i;
	struct m68k_serial *info;
	
	/* Setup base handler, and timer table. */
	init_bh(SERIAL_BH, do_serial_bh);
	show_serial_version();

	/* Initialize the tty_driver structure */
	/* SPARC: Not all of this is exactly right for us. */
	
	memset(&serial_driver, 0, sizeof(struct tty_driver));
	serial_driver.magic = TTY_DRIVER_MAGIC;
	serial_driver.name = "ttyS";
	serial_driver.major = TTY_MAJOR;
	serial_driver.minor_start = 64;
	serial_driver.num = NR_PORTS;
	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;
	serial_driver.refcount = &serial_refcount;
	serial_driver.table = serial_table;
	serial_driver.termios = serial_termios;
	serial_driver.termios_locked = serial_termios_locked;

	serial_driver.open = rs_open;
	serial_driver.close = rs_close;
	serial_driver.write = rs_write;
	serial_driver.flush_chars = rs_flush_chars;
	serial_driver.write_room = rs_write_room;
	serial_driver.chars_in_buffer = rs_chars_in_buffer;
	serial_driver.flush_buffer = rs_flush_buffer;
	serial_driver.ioctl = rs_ioctl;
	serial_driver.throttle = rs_throttle;
	serial_driver.unthrottle = rs_unthrottle;
	serial_driver.set_termios = rs_set_termios;
	serial_driver.stop = rs_stop;
	serial_driver.start = rs_start;
	serial_driver.hangup = rs_hangup;
	serial_driver.set_ldisc = rs_set_ldisc;

	/*
	 * The callout device is just like normal device except for
	 * major number and the subtype code.
	 */
	callout_driver = serial_driver;
	callout_driver.name = "cua";
	callout_driver.major = TTYAUX_MAJOR;
	callout_driver.subtype = SERIAL_TYPE_CALLOUT;

	if (tty_register_driver(&serial_driver))
		panic("Couldn't register serial driver\n");
	if (tty_register_driver(&callout_driver))
		panic("Couldn't register callout driver\n");
	
	save_flags(flags); cli();

	for(i=0;i<NR_PORTS;i++) {

	    info = &m68k_soft[i];
	    info->magic = SERIAL_MAGIC;
	    info->port = &uart_addr[i];
	    info->tty = 0;
	    info->irq = uart_irqs[i];
	    info->custom_divisor = 16;
	    info->close_delay = 50;
	    info->closing_wait = 3000;
	    info->x_char = 0;
	    info->event = 0;
	    info->count = 0;
	    info->blocked_open = 0;
	    info->tqueue.routine = do_softint;
	    info->tqueue.data = info;
	    info->tqueue_hangup.routine = do_serial_hangup;
	    info->tqueue_hangup.data = info;
	    info->callout_termios =callout_driver.init_termios;
	    info->normal_termios = serial_driver.init_termios;
	    init_waitqueue_head(&info->open_wait);
	    init_waitqueue_head(&info->close_wait);
	    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");
	    
	    IRQ_ports[info->irq] = info;	/* waste of space */

	    if (request_irq(uart_irqs[i],
			    rs_interrupt,
			    IRQ_FLG_STD,
			    "M68328_UART", NULL))
                panic("Unable to attach 68328 serial interrupt\n");
	}
	restore_flags(flags);
	return 0;
}

/*
 * register_serial and unregister_serial allows for serial ports to be
 * configured at run-time, to support PCMCIA modems.
 */
/* SPARC: Unused at this time, just here to make things link. */
int register_serial(struct serial_struct *req)
{
	return -1;
}

void unregister_serial(int line)
{
	return;
}
	
module_init(rs68328_init);
/* DAVIDM module_exit(rs68328_fini); */



static void m68328_set_baud()
{
	unsigned short ustcnt;
	int	i;

	ustcnt = USTCNT;
	USTCNT = ustcnt & ~USTCNT_TXEN;

again:
	for (i = 0; i < sizeof(baud_table) / sizeof(baud_table[0]); i++)
		if (baud_table[i] == m68328_console_baud)
			break;
	if (i >= sizeof(baud_table) / sizeof(baud_table[0])) {
		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 < BAUD_TABLE_SIZE; i++)
		if (baud_table[i] == n)
			break;
	if (i < BAUD_TABLE_SIZE) {
		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 kdev_t m68328_console_device(struct console *c)
{
	return MKDEV(TTY_MAJOR, 64 + c->index);
}


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,
	read:		NULL,
	device:		m68328_console_device,
	wait_key:	NULL,
	unblank:	NULL,
	setup:		m68328_console_setup,
	flags:		CON_PRINTBUFFER,
	index:		-1,
	cflag:		0,
	next:		NULL
};


void m68328_console_init(void)
{
	register_console(&m68328_driver);
}