specialix.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 2,265 行 · 第 1/4 页

	
	/* Set input FIFO size (1-8 bytes) */
	cor3 |= SPECIALIX_RXFIFO; 
	/* Setting up CD186x channel registers */
	sx_out(bp, CD186x_COR1, cor1);
	sx_out(bp, CD186x_COR2, port->COR2);
	sx_out(bp, CD186x_COR3, cor3);
	/* Make CD186x know about registers change */
	sx_wait_CCR(bp);
	sx_out(bp, CD186x_CCR, CCR_CORCHG1 | CCR_CORCHG2 | CCR_CORCHG3);
	/* Setting up modem option registers */
#ifdef DEBUG_SPECIALIX
	printk ("Mcor1 = %02x, mcor2 = %02x.\n", mcor1, mcor2);
#endif
	sx_out(bp, CD186x_MCOR1, mcor1);
	sx_out(bp, CD186x_MCOR2, mcor2);
	/* Enable CD186x transmitter & receiver */
	sx_wait_CCR(bp);
	sx_out(bp, CD186x_CCR, CCR_TXEN | CCR_RXEN);
	/* Enable interrupts */
	sx_out(bp, CD186x_IER, port->IER);
	/* And finally set the modem lines... */
	sx_out(bp, CD186x_MSVR, port->MSVR);
}


/* Must be called with interrupts enabled */
static int sx_setup_port(struct specialix_board *bp, struct specialix_port *port)
{
	unsigned long flags;
	
	if (port->flags & ASYNC_INITIALIZED)
		return 0;
	
	if (!port->xmit_buf) {
		/* We may sleep in get_zeroed_page() */
		unsigned long tmp;
		
		if (!(tmp = get_zeroed_page(GFP_KERNEL)))
			return -ENOMEM;

		if (port->xmit_buf) {
			free_page(tmp);
			return -ERESTARTSYS;
		}
		port->xmit_buf = (unsigned char *) tmp;
	}
		
	save_flags(flags); cli();
		
	if (port->tty) 
		clear_bit(TTY_IO_ERROR, &port->tty->flags);
		
	if (port->count == 1) 
		bp->count++;
		
	port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
	sx_change_speed(bp, port);
	port->flags |= ASYNC_INITIALIZED;
		
	restore_flags(flags);
	return 0;
}


/* Must be called with interrupts disabled */
static void sx_shutdown_port(struct specialix_board *bp, struct specialix_port *port)
{
	struct tty_struct *tty;
	
	if (!(port->flags & ASYNC_INITIALIZED)) 
		return;
	
#ifdef SX_REPORT_OVERRUN
	printk(KERN_INFO "sx%d: port %d: Total %ld overruns were detected.\n",
	       board_No(bp), port_No(port), port->overrun);
#endif	
#ifdef SX_REPORT_FIFO
	{
		int i;
		
		printk(KERN_INFO "sx%d: port %d: FIFO hits [ ",
		       board_No(bp), port_No(port));
		for (i = 0; i < 10; i++) {
			printk("%ld ", port->hits[i]);
		}
		printk("].\n");
	}
#endif	
	if (port->xmit_buf) {
		free_page((unsigned long) port->xmit_buf);
		port->xmit_buf = NULL;
	}

	/* Select port */
	sx_out(bp, CD186x_CAR, port_No(port));

	if (!(tty = port->tty) || C_HUPCL(tty)) {
		/* Drop DTR */
		sx_out(bp, CD186x_MSVDTR, 0);
	}
	
	/* Reset port */
	sx_wait_CCR(bp);
	sx_out(bp, CD186x_CCR, CCR_SOFTRESET);
	/* Disable all interrupts from this port */
	port->IER = 0;
	sx_out(bp, CD186x_IER, port->IER);
	
	if (tty)
		set_bit(TTY_IO_ERROR, &tty->flags);
	port->flags &= ~ASYNC_INITIALIZED;
	
	if (--bp->count < 0) {
		printk(KERN_ERR "sx%d: sx_shutdown_port: bad board count: %d\n",
		       board_No(bp), bp->count);
		bp->count = 0;
	}
	
	/*
	 * If this is the last opened port on the board
	 * shutdown whole board
	 */
	if (!bp->count) 
		sx_shutdown_board(bp);
}

	
static int block_til_ready(struct tty_struct *tty, struct file * filp,
                           struct specialix_port *port)
{
	DECLARE_WAITQUEUE(wait,  current);
	struct specialix_board *bp = port_Board(port);
	int    retval;
	int    do_clocal = 0;
	int    CD;

	/*
	 * If the device is in the middle of being closed, then block
	 * until it's done, and then try again.
	 */
	if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) {
		interruptible_sleep_on(&port->close_wait);
		if (port->flags & ASYNC_HUP_NOTIFY)
			return -EAGAIN;
		else
			return -ERESTARTSYS;
	}
	
	/*
	 * 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))) {
		port->flags |= ASYNC_NORMAL_ACTIVE;
		return 0;
	}

	if (C_CLOCAL(tty))
		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(&port->open_wait, &wait);
	cli();
	if (!tty_hung_up_p(filp))
		port->count--;
	sti();
	port->blocked_open++;
	while (1) {
		cli();
		sx_out(bp, CD186x_CAR, port_No(port));
		CD = sx_in(bp, CD186x_MSVR) & MSVR_CD;
		if (SX_CRTSCTS (tty)) {
			/* Activate RTS */
			port->MSVR |= MSVR_DTR;		/* WTF? */
			sx_out (bp, CD186x_MSVR, port->MSVR);
		} else {
			/* Activate DTR */
			port->MSVR |= MSVR_DTR;
			sx_out (bp, CD186x_MSVR, port->MSVR);
		} 
		sti();
		set_current_state(TASK_INTERRUPTIBLE);
		if (tty_hung_up_p(filp) ||
		    !(port->flags & ASYNC_INITIALIZED)) {
			if (port->flags & ASYNC_HUP_NOTIFY)
				retval = -EAGAIN;
			else
				retval = -ERESTARTSYS;	
			break;
		}
		if (!(port->flags & ASYNC_CLOSING) &&
		    (do_clocal || CD))
			break;
		if (signal_pending(current)) {
			retval = -ERESTARTSYS;
			break;
		}
		schedule();
	}
	current->state = TASK_RUNNING;
	remove_wait_queue(&port->open_wait, &wait);
	if (!tty_hung_up_p(filp))
		port->count++;
	port->blocked_open--;
	if (retval)
		return retval;
	
	port->flags |= ASYNC_NORMAL_ACTIVE;
	return 0;
}	


static int sx_open(struct tty_struct * tty, struct file * filp)
{
	int board;
	int error;
	struct specialix_port * port;
	struct specialix_board * bp;
	
	board = SX_BOARD(tty->index);

	if (board >= SX_NBOARD || !(sx_board[board].flags & SX_BOARD_PRESENT))
		return -ENODEV;
	
	bp = &sx_board[board];
	port = sx_port + board * SX_NPORT + SX_PORT(tty->index);

#ifdef DEBUG_SPECIALIX
	printk (KERN_DEBUG "Board = %d, bp = %p, port = %p, portno = %d.\n", 
	        board, bp, port, SX_PORT(tty->index));
#endif

	if (sx_paranoia_check(port, tty->name, "sx_open"))
		return -ENODEV;

	if ((error = sx_setup_board(bp)))
		return error;

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

	if ((error = sx_setup_port(bp, port))) 
		return error;
	
	if ((error = block_til_ready(tty, filp, port)))
		return error;

	return 0;
}


static void sx_close(struct tty_struct * tty, struct file * filp)
{
	struct specialix_port *port = (struct specialix_port *) tty->driver_data;
	struct specialix_board *bp;
	unsigned long flags;
	unsigned long timeout;
	
	if (!port || sx_paranoia_check(port, tty->name, "close"))
		return;
	
	save_flags(flags); cli();
	if (tty_hung_up_p(filp)) {
		restore_flags(flags);
		return;
	}
	
	bp = port_Board(port);
	if ((tty->count == 1) && (port->count != 1)) {
		printk(KERN_ERR "sx%d: sx_close: bad port count;"
		       " tty->count is 1, port count is %d\n",
		       board_No(bp), port->count);
		port->count = 1;
	}
	if (--port->count < 0) {
		printk(KERN_ERR "sx%d: sx_close: bad port count for tty%d: %d\n",
		       board_No(bp), port_No(port), port->count);
		port->count = 0;
	}
	if (port->count) {
		restore_flags(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.
	 */
	port->IER &= ~IER_RXD;
	if (port->flags & ASYNC_INITIALIZED) {
		port->IER &= ~IER_TXRDY;
		port->IER |= IER_TXEMPTY;
		sx_out(bp, CD186x_CAR, port_No(port));
		sx_out(bp, CD186x_IER, port->IER);
		/*
		 * Before we drop DTR, make sure the UART transmitter
		 * has completely drained; this is especially
		 * important if there is a transmit FIFO!
		 */
		timeout = jiffies+HZ;
		while(port->IER & IER_TXEMPTY) {
			current->state = TASK_INTERRUPTIBLE;
 			schedule_timeout(port->timeout);
			if (time_after(jiffies, timeout)) {
				printk (KERN_INFO "Timeout waiting for close\n");
				break;
			}
		}

	}
	sx_shutdown_port(bp, port);
	if (tty->driver->flush_buffer)
		tty->driver->flush_buffer(tty);
	tty_ldisc_flush(tty);
	tty->closing = 0;
	port->event = 0;
	port->tty = NULL;
	if (port->blocked_open) {
		if (port->close_delay) {
			current->state = TASK_INTERRUPTIBLE;
			schedule_timeout(port->close_delay);
		}
		wake_up_interruptible(&port->open_wait);
	}
	port->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
	wake_up_interruptible(&port->close_wait);
	restore_flags(flags);
}


static int sx_write(struct tty_struct * tty, int from_user, 
                    const unsigned char *buf, int count)
{
	struct specialix_port *port = (struct specialix_port *)tty->driver_data;
	struct specialix_board *bp;
	int c, total = 0;
	unsigned long flags;
				
	if (sx_paranoia_check(port, tty->name, "sx_write"))
		return 0;
	
	bp = port_Board(port);

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

	save_flags(flags);
	if (from_user) {
		down(&tmp_buf_sem);
		while (1) {
			c = min_t(int, count, min(SERIAL_XMIT_SIZE - port->xmit_cnt - 1,
					   SERIAL_XMIT_SIZE - port->xmit_head));
			if (c <= 0)
				break;

			c -= copy_from_user(tmp_buf, buf, c);
			if (!c) {
				if (!total)
					total = -EFAULT;
				break;
			}

			cli();
			c = min_t(int, c, min(SERIAL_XMIT_SIZE - port->xmit_cnt - 1,
				       SERIAL_XMIT_SIZE - port->xmit_head));
			memcpy(port->xmit_buf + port->xmit_head, tmp_buf, c);
			port->xmit_head = (port->xmit_head + c) & (SERIAL_XMIT_SIZE-1);
			port->xmit_cnt += c;
			restore_flags(flags);

			buf += c;
			count -= c;
			total += c;
		}
		up(&tmp_buf_sem);
	} else {
		while (1) {
			cli();
			c = min_t(int, count, min(SERIAL_XMIT_SIZE - port->xmit_cnt - 1,
					   SERIAL_XMIT_SIZE - port->xmit_head));
			if (c <= 0) {
				restore_flags(flags);
				break;
			}
			memcpy(port->xmit_buf + port->xmit_head, buf, c);
			port->xmit_head = (port->xmit_head + c) & (SERIAL_XMIT_SIZE-1);
			port->xmit_cnt += c;
			restore_flags(flags);

			buf += c;
			count -= c;
			total += c;
		}
	}

	cli();
	if (port->xmit_cnt && !tty->stopped && !tty->hw_stopped &&
	    !(port->IER & IER_TXRDY)) {
		port->IER |= IER_TXRDY;
		sx_out(bp, CD186x_CAR, port_No(port));
		sx_out(bp, CD186x_IER, port->IER);
	}
	restore_flags(flags);
	return total;
}


static void sx_put_char(struct tty_struct * tty, unsigned char ch)
{
	struct specialix_port *port = (struct specialix_port *)tty->driver_data;
	unsigned long flags;

	if (sx_paranoia_check(port, tty->name, "sx_put_char"))
		return;

	if (!tty || !port->xmit_buf)
		return;

	save_flags(flags); cli();
	
	if (port->xmit_cnt >= SERIAL_XMIT_SIZE - 1) {
		restore_flags(flags);
		return;
	}

	port->xmit_buf[port->xmit_head++] = ch;
	port->xmit_head &= SERIAL_XMIT_SIZE - 1;
	port->xmit_cnt++;
	restore_flags(flags);
}


static void sx_flush_chars(struct tty_struct * tty)
{
	struct specialix_port *port = (struct specialix_port *)tty->driver_data;
	unsigned long flags;
				
	if (sx_paranoia_check(port, tty->name, "sx_flush_chars"))
		return;
	
	if (port->xmit_cnt <= 0 || tty->stopped || tty->hw_stopped ||
	    !port->xmit_buf)
		return;

	save_flags(flags); cli();
	port->IER |= IER_TXRDY;
	sx_out(port_Board(port), CD186x_CAR, port_No(port));
	sx_out(port_Board(port), CD186x_IER, port->IER);
	restore_flags(flags);
}


static int sx_write_room(struct tty_struct * tty)
{
	struct specialix_port *port = (struct specialix_port *)tty->driver_data;
	int	ret;
				
	if (sx_paranoia_check(port, tty->name, "sx_write_room"))
		return 0;

	ret = SERIAL_XMIT_SIZE - port->xmit_cnt - 1;
	if (ret < 0)
		ret = 0;
	return ret;
}


static int sx_chars_in_buffer(struct tty_struct *tty)
{
	struct specialix_port *port = (struct specialix_port *)tty->driver_data;
				
	if (sx_paranoia_check(port, tty->name, "sx_chars_in_buffer"))
		return 0;
	
	return port->xmit_cnt;
}


static void sx_flush_buffer(struct tty_struct *tty)
{
	struct specialix_port *port = (struct specialix_port *)tty->driver_data;
	unsigned long flags;
				
	if (sx_paranoia_check(port, tty->name, "sx_flush_buffer"))
		return;

	save_flags(flags); cli();
	port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
	restore_flags(flags);
	
	tty_wakeup(tty);
	wake_up_interruptible(&tty->write_wait);
}


static int sx_tiocmget(struct tty_struct *tty, struct file *file)
{
	struct specialix_port *port = (struct specialix_port *)tty->driver_data;
	struct specialix_board * bp;
	unsigned char status;
	unsigned int result;
	unsigned long flags;

	if (sx_paranoia_check(port, tty->name, __FUNCTION__))
		return -ENODEV;

	bp = port_Board(port);
	save_flags(flags); cli();
	sx_out(bp, CD186x_CAR, port_No(port));
	status = sx_in(bp, CD186x_MSVR);
	restore_flags(flags);
#ifdef DEBUG_SPECIALIX
	printk (KERN_DEBUG "Got msvr[%d] = %02x, car = %d.\n", 
		port_No(port), status, sx_in (bp, CD186x_CAR));
	printk (KERN_DEBUG "sx_port = %p, port = %p\n", sx_port, port);
#endif
	if (SX_CRTSCTS(port->tty)) {
		result  = /*   (status & MSVR_RTS) ? */ TIOCM_DTR /* : 0) */ 
		          |   ((status & MSVR_DTR) ? TIOCM_RTS : 0)
		          |   ((status & MSVR_CD)  ? TIOCM_CAR : 0)
		          |/* ((status & MSVR_DSR) ? */ TIOCM_DSR /* : 0) */
		          |   ((status & MSVR_CTS) ? TIOCM_CTS : 0);
	} else {
		result  = /*   (status & MSVR_RTS) ? */ TIOCM_RTS /* : 0) */ 
		          |   ((status & MSVR_DTR) ? TIOCM_DTR : 0)
		          |   ((status & MSVR_CD)  ? TIOCM_CAR : 0)
		          |/* ((status & MSVR_DSR) ? */ TIOCM_DSR /* : 0) */
		          |   ((status & MSVR_CTS) ? TIOCM_CTS : 0);
	}

	return result;
}


static int sx_tiocmset(struct tty_struct *tty, struct file *file,
		       unsigned int set, unsigned int clear)
{
	struct specialix_port *port = (struct specialix_port *)tty->driver_data;
	unsigned long flags;
	struct specialix_board *bp;

	if (sx_paranoia_check(port, tty->name, __FUNCTION__))
		return -ENODEV;

	bp = port_Board(port);

	save_flags(flags); cli();
   /*	if (set & TIOCM_RTS)