esp.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 2,491 行 · 第 1/5 页

	
	if (tty_hung_up_p(filp)) {
		DBG_CNT("before DEC-hung");
		goto out;
	}
	
#ifdef SERIAL_DEBUG_OPEN
	printk("rs_close ttys%d, count = %d\n", info->line, info->count);
#endif
	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) {
		DBG_CNT("before DEC-2");
		goto out;
	}
	info->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 (info->closing_wait != ASYNC_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.
	 */
	/* info->IER &= ~UART_IER_RLSI; */
	info->IER &= ~UART_IER_RDI;
	info->read_status_mask &= ~UART_LSR_DR;
	if (info->flags & ASYNC_INITIALIZED) {
		serial_out(info, UART_ESI_CMD1, ESI_SET_SRV_MASK);
		serial_out(info, UART_ESI_CMD2, info->IER);

		/* disable receive timeout */
		serial_out(info, UART_ESI_CMD1, ESI_SET_RX_TIMEOUT);
		serial_out(info, UART_ESI_CMD2, 0x00);

		/*
		 * Before we drop DTR, make sure the UART transmitter
		 * has completely drained; this is especially
		 * important if there is a transmit FIFO!
		 */
		rs_wait_until_sent(tty, info->timeout);
	}
	shutdown(info);
	if (tty->driver->flush_buffer)
		tty->driver->flush_buffer(tty);
	tty_ldisc_flush(tty);
	tty->closing = 0;
	info->event = 0;
	info->tty = NULL;

	if (info->blocked_open) {
		if (info->close_delay) {
			set_current_state(TASK_INTERRUPTIBLE);
			schedule_timeout(info->close_delay);
		}
		wake_up_interruptible(&info->open_wait);
	}
	info->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
	wake_up_interruptible(&info->close_wait);
out:
	restore_flags(flags);
}

static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
{
	struct esp_struct *info = (struct esp_struct *)tty->driver_data;
	unsigned long orig_jiffies, char_time;
	unsigned long flags;

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

	orig_jiffies = jiffies;
	char_time = ((info->timeout - HZ / 50) / 1024) / 5;

	if (!char_time)
		char_time = 1;

	save_flags(flags); cli();
	serial_out(info, UART_ESI_CMD1, ESI_NO_COMMAND);
	serial_out(info, UART_ESI_CMD1, ESI_GET_TX_AVAIL);

	while ((serial_in(info, UART_ESI_STAT1) != 0x03) ||
		(serial_in(info, UART_ESI_STAT2) != 0xff)) {
		set_current_state(TASK_INTERRUPTIBLE);
		schedule_timeout(char_time);

		if (signal_pending(current))
			break;

		if (timeout && time_after(jiffies, orig_jiffies + timeout))
			break;

		serial_out(info, UART_ESI_CMD1, ESI_NO_COMMAND);
		serial_out(info, UART_ESI_CMD1, ESI_GET_TX_AVAIL);
	}
	
	restore_flags(flags);
	set_current_state(TASK_RUNNING);
}

/*
 * esp_hangup() --- called by tty_hangup() when a hangup is signaled.
 */
static void esp_hangup(struct tty_struct *tty)
{
	struct esp_struct * info = (struct esp_struct *)tty->driver_data;
	
	if (serial_paranoia_check(info, tty->name, "esp_hangup"))
		return;
	
	rs_flush_buffer(tty);
	shutdown(info);
	info->event = 0;
	info->count = 0;
	info->flags &= ~ASYNC_NORMAL_ACTIVE;
	info->tty = NULL;
	wake_up_interruptible(&info->open_wait);
}

/*
 * ------------------------------------------------------------
 * esp_open() and friends
 * ------------------------------------------------------------
 */
static int block_til_ready(struct tty_struct *tty, struct file * filp,
			   struct esp_struct *info)
{
	DECLARE_WAITQUEUE(wait, current);
	int		retval;
	int		do_clocal = 0;
	unsigned long	flags;

	/*
	 * 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) ||
	    (info->flags & ASYNC_CLOSING)) {
		if (info->flags & ASYNC_CLOSING)
			interruptible_sleep_on(&info->close_wait);
#ifdef SERIAL_DO_RESTART
		if (info->flags & ASYNC_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 |= ASYNC_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);
#ifdef SERIAL_DEBUG_OPEN
	printk("block_til_ready before block: ttys%d, count = %d\n",
	       info->line, info->count);
#endif
	save_flags(flags);
	cli();
	if (!tty_hung_up_p(filp)) 
		info->count--;
	restore_flags(flags);
	info->blocked_open++;
	while (1) {
		save_flags(flags);
		cli();
		if ((tty->termios->c_cflag & CBAUD)) {
			unsigned int scratch;

			serial_out(info, UART_ESI_CMD1, ESI_READ_UART);
			serial_out(info, UART_ESI_CMD2, UART_MCR);
			scratch = serial_in(info, UART_ESI_STAT1);
			serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
			serial_out(info, UART_ESI_CMD2, UART_MCR);
			serial_out(info, UART_ESI_CMD2,
				scratch | UART_MCR_DTR | UART_MCR_RTS);
		}
		restore_flags(flags);
		set_current_state(TASK_INTERRUPTIBLE);
		if (tty_hung_up_p(filp) ||
		    !(info->flags & ASYNC_INITIALIZED)) {
#ifdef SERIAL_DO_RESTART
			if (info->flags & ASYNC_HUP_NOTIFY)
				retval = -EAGAIN;
			else
				retval = -ERESTARTSYS;	
#else
			retval = -EAGAIN;
#endif
			break;
		}

		serial_out(info, UART_ESI_CMD1, ESI_GET_UART_STAT);
		if (serial_in(info, UART_ESI_STAT2) & UART_MSR_DCD)
			do_clocal = 1;

		if (!(info->flags & ASYNC_CLOSING) &&
		    (do_clocal))
			break;
		if (signal_pending(current)) {
			retval = -ERESTARTSYS;
			break;
		}
#ifdef SERIAL_DEBUG_OPEN
		printk("block_til_ready blocking: ttys%d, count = %d\n",
		       info->line, info->count);
#endif
		schedule();
	}
	set_current_state(TASK_RUNNING);
	remove_wait_queue(&info->open_wait, &wait);
	if (!tty_hung_up_p(filp))
		info->count++;
	info->blocked_open--;
#ifdef SERIAL_DEBUG_OPEN
	printk("block_til_ready after blocking: ttys%d, count = %d\n",
	       info->line, info->count);
#endif
	if (retval)
		return retval;
	info->flags |= ASYNC_NORMAL_ACTIVE;
	return 0;
}	

/*
 * This routine is called whenever a serial port is opened.  It
 * enables interrupts for a serial port, linking in its async structure into
 * the IRQ chain.   It also performs the serial-specific
 * initialization for the tty structure.
 */
static int esp_open(struct tty_struct *tty, struct file * filp)
{
	struct esp_struct	*info;
	int 			retval, line;

	line = tty->index;
	if ((line < 0) || (line >= NR_PORTS))
		return -ENODEV;

	/* find the port in the chain */

	info = ports;

	while (info && (info->line != line))
		info = info->next_port;

	if (!info) {
		serial_paranoia_check(info, tty->name, "esp_open");
		return -ENODEV;
	}

#ifdef SERIAL_DEBUG_OPEN
	printk("esp_open %s, count = %d\n", tty->name, info->count);
#endif
	info->count++;
	tty->driver_data = info;
	info->tty = tty;

	if (!tmp_buf) {
		tmp_buf = (unsigned char *) get_zeroed_page(GFP_KERNEL);
		if (!tmp_buf)
			return -ENOMEM;
	}
	
	/*
	 * Start up serial port
	 */
	retval = startup(info);
	if (retval)
		return retval;

	retval = block_til_ready(tty, filp, info);
	if (retval) {
#ifdef SERIAL_DEBUG_OPEN
		printk("esp_open returning after block_til_ready with %d\n",
		       retval);
#endif
		return retval;
	}

#ifdef SERIAL_DEBUG_OPEN
	printk("esp_open %s successful...", tty->name);
#endif
	return 0;
}

/*
 * ---------------------------------------------------------------------
 * espserial_init() and friends
 *
 * espserial_init() is called at boot-time to initialize the serial driver.
 * ---------------------------------------------------------------------
 */

/*
 * This routine prints out the appropriate serial driver version
 * number, and identifies which options were configured into this
 * driver.
 */
 
static _INLINE_ void show_serial_version(void)
{
 	printk(KERN_INFO "%s version %s (DMA %u)\n",
		serial_name, serial_version, dma);
}

/*
 * This routine is called by espserial_init() to initialize a specific serial
 * port.
 */
static _INLINE_ int autoconfig(struct esp_struct * info, int *region_start)
{
	int port_detected = 0;
	unsigned long flags;

	save_flags(flags); cli();
	
	/*
	 * Check for ESP card
	 */

	if (!check_region(info->port, 8) && 
	    serial_in(info, UART_ESI_BASE) == 0xf3) {
		serial_out(info, UART_ESI_CMD1, 0x00);
		serial_out(info, UART_ESI_CMD1, 0x01);

		if ((serial_in(info, UART_ESI_STAT2) & 0x70) == 0x20) {
			port_detected = 1;

			if (!(info->irq)) {
				serial_out(info, UART_ESI_CMD1, 0x02);

				if (serial_in(info, UART_ESI_STAT1) & 0x01)
					info->irq = 3;
				else
					info->irq = 4;
			}

			if (ports && (ports->port == (info->port - 8))) {
				release_region(*region_start,
					       info->port - *region_start);
			} else
				*region_start = info->port;

			if (!request_region(*region_start,
				       info->port - *region_start + 8,
				       "esp serial"))
			{
				restore_flags(flags);
				return -EIO;
			}

			/* put card in enhanced mode */
			/* this prevents access through */
			/* the "old" IO ports */
			esp_basic_init(info);

			/* clear out MCR */
			serial_out(info, UART_ESI_CMD1, ESI_WRITE_UART);
			serial_out(info, UART_ESI_CMD2, UART_MCR);
			serial_out(info, UART_ESI_CMD2, 0x00);
		}
	}

	restore_flags(flags);
	return (port_detected);
}

static struct tty_operations esp_ops = {
	.open = esp_open,
	.close = rs_close,
	.write = rs_write,
	.put_char = rs_put_char,
	.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 = esp_hangup,
	.break_ctl = esp_break,
	.wait_until_sent = rs_wait_until_sent,
	.tiocmget = esp_tiocmget,
	.tiocmset = esp_tiocmset,
};

/*
 * The serial driver boot-time initialization code!
 */
int __init espserial_init(void)
{
	int i, offset;
	int region_start;
	struct esp_struct * info;
	struct esp_struct *last_primary = NULL;
	int esp[] = {0x100,0x140,0x180,0x200,0x240,0x280,0x300,0x380};

	esp_driver = alloc_tty_driver(NR_PORTS);
	if (!esp_driver)
		return -ENOMEM;
	
	for (i = 0; i < NR_PRIMARY; i++) {
		if (irq[i] != 0) {
			if ((irq[i] < 2) || (irq[i] > 15) || (irq[i] == 6) ||
			    (irq[i] == 8) || (irq[i] == 13))
				irq[i] = 0;
			else if (irq[i] == 2)
				irq[i] = 9;
		}
	}

	if ((dma != 1) && (dma != 3))
		dma = 0;

	if ((rx_trigger < 1) || (rx_trigger > 1023))
		rx_trigger = 768;

	if ((tx_trigger < 1) || (tx_trigger > 1023))
		tx_trigger = 768;

	if ((flow_off < 1) || (flow_off > 1023))
		flow_off = 1016;
	
	if ((flow_on < 1) || (flow_on > 1023))
		flow_on = 944;

	if ((rx_timeout < 0) || (rx_timeout > 255))
		rx_timeout = 128;
	
	if (flow_on >= flow_off)
		flow_on = flow_off - 1;

	show_serial_version();

	/* Initialize the tty_driver structure */
	
	esp_driver->owner = THIS_MODULE;
	esp_driver->name = "ttyP";
	esp_driver->devfs_name = "tts/P";
	esp_driver->major = ESP_IN_MAJOR;
	esp_driver->minor_start = 0;
	esp_driver->type = TTY_DRIVER_TYPE_SERIAL;
	esp_driver->subtype = SERIAL_TYPE_NORMAL;
	esp_driver->init_termios = tty_std_termios;
	esp_driver->init_termios.c_cflag =
		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
	esp_driver->flags = TTY_DRIVER_REAL_RAW;
	tty_set_operations(esp_driver, &esp_ops);
	if (tty_register_driver(esp_driver))
	{
		printk(KERN_ERR "Couldn't register esp