68328serial.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 1,628 行 · 第 1/3 页

			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->name, "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;
	/*
	 * 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);
		
	tty_ldisc_flush(tty);
	tty->closing = 0;
	info->event = 0;
	info->tty = 0;
#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 (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_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->name, "rs_hangup"))
		return;
	
	rs_flush_buffer(tty);
	shutdown(info);
	info->event = 0;
	info->count = 0;
	info->flags &= ~S_NORMAL_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 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))) {
		info->flags |= S_NORMAL_ACTIVE;
		return 0;
	}

	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();
		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_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 = tty->index;
	
	if (line >= NR_PORTS || line < 0) /* we have exactly one */
		return -ENODEV;

	info = &m68k_soft[line];

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

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

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

	return block_til_ready(tty, filp, info);
}

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

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

#ifdef CONFIG_PM
/* Serial Power management
 *  The console (currently fixed at line 0) is a special case for power
 *  management because the kernel is so chatty. The console will be 
 *  explicitly disabled my our power manager as the last minute, so we won't
 *  mess with it here.
 */
static struct pm_dev *serial_pm[NR_PORTS];

static int serial_pm_callback(struct pm_dev *dev, pm_request_t request, void *data)
{
	struct m68k_serial *info = (struct m68k_serial *)dev->data;

	if(info == NULL)
		return -1;

	/* special case for line 0 - pm restores it */
	if(info->line == 0)
		return 0; 

	switch (request) {
	case PM_SUSPEND:
		shutdown(info);
		break;

	case PM_RESUME:
		startup(info);
		break;
	}
	return 0;
}

void shutdown_console(void)
{
	struct m68k_serial *info = &m68k_soft[0];

	/* HACK: wait a bit for any pending printk's to be dumped */
	{
		int i = 10000;
		while(i--);
	}

	shutdown(info);
}

void startup_console(void)
{
	struct m68k_serial *info = &m68k_soft[0];
	startup(info);
}
#endif


static 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,
};

/* rs_init inits the driver */
static int __init
rs68328_init(void)
{
	int flags, 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);

	if (tty_register_driver(serial_driver)) {
		put_tty_driver(serial_driver);
		printk(KERN_ERR "Couldn't register serial driver\n");
		return -ENOMEM;
	}

	save_flags(flags); cli();

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

	    info = &m68k_soft[i];
	    info->magic = SERIAL_MAGIC;
	    info->port = (int) &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;
	    INIT_WORK(&info->tqueue, do_softint, info);
	    INIT_WORK(&info->tqueue_hangup, do_serial_hangup, info);
	    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 */

#ifdef CONFIG_M68VZ328
		if (i > 0 )
			PJSEL &= 0xCF;  /* PSW enable second port output */
#endif

	    if (request_irq(uart_irqs[i],
			    rs_interrupt,
			    IRQ_FLG_STD,
			    "M68328_UART", NULL))
                panic("Unable to attach 68328 serial interrupt\n");
#ifdef CONFIG_PM
	    serial_pm[i] = pm_register(PM_SYS_DEV, PM_SYS_COM, serial_pm_callback);
	    if (serial_pm[i])
		    serial_pm[i]->data = info;
#endif
	}
	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);



static void m68328_set_baud(void)
{
	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 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);