io_edgeport.c

linux-2.4.29操作系统的源码

						edge_port->txCredits += txCredits;
						dbg("%s - txcredits for port%d = %d", __FUNCTION__, portNumber, edge_port->txCredits);

						/* tell the tty driver that something has changed */
						if (edge_port->port->tty)
							wake_up_interruptible(&edge_port->port->tty->write_wait);

						// Since we have more credit, check if more data can be sent
						send_more_port_data(edge_serial, edge_port);
					}
				}
			}
			position += 2;
			++portNumber;
		}
	}
}


/*****************************************************************************
 * edge_bulk_in_callback
 *	this is the callback function for when we have received data on the 
 *	bulk in endpoint.
 *****************************************************************************/
static void edge_bulk_in_callback (struct urb *urb)
{
	struct edgeport_serial	*edge_serial = (struct edgeport_serial *)urb->context;
	unsigned char		*data = urb->transfer_buffer;
	int			status;
	__u16			raw_data_length;

	dbg("%s", __FUNCTION__);

	if (serial_paranoia_check (edge_serial->serial, __FUNCTION__)) {
		return;
	}

	if (urb->status) {
		dbg("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status);
		return;
	}

	if (urb->actual_length) {
		raw_data_length = urb->actual_length;

		usb_serial_debug_data (__FILE__, __FUNCTION__, raw_data_length, data);

		/* decrement our rxBytes available by the number that we just got */
		edge_serial->rxBytesAvail -= raw_data_length;

		dbg("%s - Received = %d, rxBytesAvail %d", __FUNCTION__, raw_data_length, edge_serial->rxBytesAvail);

		process_rcvd_data (edge_serial, data, urb->actual_length);

		/* check to see if there's any more data for us to read */
		if ((edge_serial->rxBytesAvail > 0) &&
		    (edge_serial->read_urb->status != -EINPROGRESS)) {
			dbg(" --- Posting a read");

			/* there is, so resubmit our urb */
			edge_serial->read_urb->dev = edge_serial->serial->dev;
			status = usb_submit_urb(edge_serial->read_urb);
			if (status) {
				err("%s - usb_submit_urb(read bulk) failed, status = %d", __FUNCTION__, status);
			}
		}
	}
}


/*****************************************************************************
 * edge_bulk_out_data_callback
 *	this is the callback function for when we have finished sending serial data
 *	on the bulk out endpoint.
 *****************************************************************************/
static void edge_bulk_out_data_callback (struct urb *urb)
{
	struct edgeport_port *edge_port = (struct edgeport_port *)urb->context;
	struct tty_struct *tty;

	dbg("%s", __FUNCTION__);

	if (port_paranoia_check (edge_port->port, __FUNCTION__)) {
		return;
	}

	if (urb->status) {
		dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
	}

	tty = edge_port->port->tty;

	if (tty && edge_port->open) {
		/* let the tty driver wakeup if it has a special write_wakeup function */
		tty_wakeup(tty);
	}

	// Release the Write URB
	edge_port->write_in_progress = FALSE;

	// Check if more data needs to be sent
	send_more_port_data((struct edgeport_serial *)(edge_port->port->serial->private), edge_port);
}


/*****************************************************************************
 * BulkOutCmdCallback
 *	this is the callback function for when we have finished sending a command
 *	on the bulk out endpoint.
 *****************************************************************************/
static void edge_bulk_out_cmd_callback (struct urb *urb)
{
	struct edgeport_port *edge_port = (struct edgeport_port *)urb->context;
	struct tty_struct *tty;
	int status = urb->status;

	dbg("%s", __FUNCTION__);

	CmdUrbs--;
	dbg("%s - FREE URB %p (outstanding %d)", __FUNCTION__, urb, CmdUrbs);


	/* clean up the transfer buffer */
	if (urb->transfer_buffer != NULL) {
		kfree(urb->transfer_buffer);
	}

	// Free the command urb
	usb_unlink_urb (urb);
	usb_free_urb   (urb);

	if (port_paranoia_check (edge_port->port, __FUNCTION__)) {
		return;
	}

	if (status) {
		dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, status);
		return;
	}

	/* Get pointer to tty */
	tty = edge_port->port->tty;

	/* tell the tty driver that something has changed */
	if (tty && edge_port->open)
		wake_up_interruptible(&tty->write_wait);

	/* we have completed the command */
	edge_port->commandPending = FALSE;
	wake_up_interruptible(&edge_port->wait_command);
}


/*****************************************************************************
 * Driver tty interface functions
 *****************************************************************************/

/*****************************************************************************
 * SerialOpen
 *	this function is called by the tty driver when a port is opened
 *	If successful, we return 0
 *	Otherwise we return a negative error number.
 *****************************************************************************/
static int edge_open (struct usb_serial_port *port, struct file * filp)
{
	struct edgeport_port *edge_port = (struct edgeport_port *)port->private;
	struct usb_serial *serial;
	struct edgeport_serial *edge_serial;
	int response;
	int timeout;

	if (port_paranoia_check (port, __FUNCTION__))
		return -ENODEV;
	
	dbg("%s - port %d", __FUNCTION__, port->number);

	if (edge_port == NULL)
		return -ENODEV;

	/* force low_latency on so that our tty_push actually forces the data through, 
	   otherwise it is scheduled, and with high data rates (like with OHCI) data
	   can get lost. */
	if (port->tty)
		port->tty->low_latency = 1;

	/* see if we've set up our endpoint info yet (can't set it up in edge_startup
	   as the structures were not set up at that time.) */
	serial = port->serial;
	edge_serial = (struct edgeport_serial *)serial->private;
	if (edge_serial == NULL) {
		return -ENODEV;
	}
	if (edge_serial->interrupt_in_buffer == NULL) {
		struct usb_serial_port *port0 = &serial->port[0];
		
		/* not set up yet, so do it now */
		edge_serial->interrupt_in_buffer = port0->interrupt_in_buffer;
		edge_serial->interrupt_in_endpoint = port0->interrupt_in_endpointAddress;
		edge_serial->interrupt_read_urb = port0->interrupt_in_urb;
		edge_serial->bulk_in_buffer = port0->bulk_in_buffer;
		edge_serial->bulk_in_endpoint = port0->bulk_in_endpointAddress;
		edge_serial->read_urb = port0->read_urb;
		edge_serial->bulk_out_endpoint = port0->bulk_out_endpointAddress;
	
		/* set up our interrupt urb */
		FILL_INT_URB(edge_serial->interrupt_read_urb,
			     serial->dev,
			     usb_rcvintpipe(serial->dev,
					    port0->interrupt_in_endpointAddress),
			     port0->interrupt_in_buffer,
			     edge_serial->interrupt_read_urb->transfer_buffer_length,
			     edge_interrupt_callback, edge_serial,
			     edge_serial->interrupt_read_urb->interval);
		
		/* set up our bulk in urb */
		FILL_BULK_URB(edge_serial->read_urb, serial->dev,
			      usb_rcvbulkpipe(serial->dev, port0->bulk_in_endpointAddress),
			      port0->bulk_in_buffer,
			      edge_serial->read_urb->transfer_buffer_length,
			      edge_bulk_in_callback, edge_serial);

		/* start interrupt read for this edgeport
		 * this interrupt will continue as long as the edgeport is connected */
		response = usb_submit_urb (edge_serial->interrupt_read_urb);
		if (response) {
			err("%s - Error %d submitting control urb", __FUNCTION__, response);
		}
	}
	
	/* initialize our wait queues */
	init_waitqueue_head(&edge_port->wait_open);
	init_waitqueue_head(&edge_port->wait_chase);
	init_waitqueue_head(&edge_port->delta_msr_wait);
	init_waitqueue_head(&edge_port->wait_command);

	/* initialize our icount structure */
	memset (&(edge_port->icount), 0x00, sizeof(edge_port->icount));

	/* initialize our port settings */
	edge_port->txCredits            = 0;			/* Can't send any data yet */
	edge_port->shadowMCR            = MCR_MASTER_IE;	/* Must always set this bit to enable ints! */
	edge_port->chaseResponsePending = FALSE;

	/* send a open port command */
	edge_port->openPending = TRUE;
	edge_port->open        = FALSE;
	response = send_iosp_ext_cmd (edge_port, IOSP_CMD_OPEN_PORT, 0);

	if (response < 0) {
		err("%s - error sending open port command", __FUNCTION__);
		edge_port->openPending = FALSE;
		return -ENODEV;
	}

	/* now wait for the port to be completly opened */
	timeout = OPEN_TIMEOUT;
	while (timeout && edge_port->openPending == TRUE) {
		timeout = interruptible_sleep_on_timeout (&edge_port->wait_open, timeout);
	}

	if (edge_port->open == FALSE) {
		/* open timed out */
		dbg("%s - open timedout", __FUNCTION__);
		edge_port->openPending = FALSE;
		return -ENODEV;
	}

	/* create the txfifo */
	edge_port->txfifo.head	= 0;
	edge_port->txfifo.tail	= 0;
	edge_port->txfifo.count	= 0;
	edge_port->txfifo.size	= edge_port->maxTxCredits;
	edge_port->txfifo.fifo	= kmalloc (edge_port->maxTxCredits, GFP_KERNEL);

	if (!edge_port->txfifo.fifo) {
		dbg("%s - no memory", __FUNCTION__);
		edge_close (port, filp);
		return -ENOMEM;
	}

	/* Allocate a URB for the write */
	edge_port->write_urb = usb_alloc_urb (0);

	if (!edge_port->write_urb) {
		dbg("%s - no memory", __FUNCTION__);
		edge_close (port, filp);
		return -ENOMEM;
	}

	dbg("%s(%d) - Initialize TX fifo to %d bytes", __FUNCTION__, port->number, edge_port->maxTxCredits);

	dbg("%s exited", __FUNCTION__);

	return 0;
}


/************************************************************************
 *
 * block_until_chase_response
 *
 *	This function will block the close until one of the following:
 *		1. Response to our Chase comes from Edgeport
 *		2. A timout of 10 seconds without activity has expired
 *		   (1K of Edgeport data @ 2400 baud ==> 4 sec to empty)
 *
 ************************************************************************/
static void block_until_chase_response(struct edgeport_port *edge_port)
{
	__u16 lastCredits;
	int timeout = 1*HZ;
	int wait = 10;

	while (1) {
		// Save Last credits
		lastCredits = edge_port->txCredits;

		// Did we get our Chase response
		if (edge_port->chaseResponsePending == FALSE) {
			dbg("%s - Got Chase Response", __FUNCTION__);

			// did we get all of our credit back?
			if (edge_port->txCredits == edge_port->maxTxCredits ) {
				dbg("%s - Got all credits", __FUNCTION__);
				return;
			}
		}

		// Block the thread for a while
		interruptible_sleep_on_timeout (&edge_port->wait_chase, timeout);

		if (lastCredits == edge_port->txCredits) {
			// No activity.. count down.
			wait--;
			if (wait == 0) {
				edge_port->chaseResponsePending = FALSE;
				dbg("%s - Chase TIMEOUT", __FUNCTION__);
				return;
			}
		} else {
			// Reset timout value back to 10 seconds
			dbg("%s - Last %d, Current %d", __FUNCTION__, lastCredits, edge_port->txCredits);
			wait = 10;
		}
	}
}


/************************************************************************
 *
 * block_until_tx_empty
 *
 *	This function will block the close until one of the following:
 *		1. TX count are 0
 *		2. The edgeport has stopped
 *		3. A timout of 3 seconds without activity has expired
 *
 ************************************************************************/
static void block_until_tx_empty (struct edgeport_port *edge_port)
{
	struct TxFifo *fifo = &edge_port->txfifo;
	__u32 lastCount;
	int timeout = HZ/10;
	int wait = 30;

	while (1) {
		// Save Last count
		lastCount = fifo->count;

		// Is the Edgeport Buffer empty?
		if (lastCount == 0) {
			dbg("%s - TX Buffer Empty", __FUNCTION__);
			return;
		}

		// Block the thread for a while
		interruptible_sleep_on_timeout (&edge_port->wait_chase, timeout);

		dbg("%s wait", __FUNCTION__);

		if (lastCount == fifo->count) {
			// No activity.. count down.
			wait--;
			if (wait == 0) {
				dbg("%s - TIMEOUT", __FUNCTION__);
				return;
			}
		} else {
			// Reset timout value back to seconds
			wait = 30;
		}
	}
}


/*****************************************************************************
 * edge_close
 *	this function is called by the tty driver when a port is closed
 *****************************************************************************/
static void edge_close (struct usb_serial_port *port, struct file * filp)
{
	struct usb_serial *serial;
	struct edgeport_serial *edge_serial;
	struct edgeport_port *edge_port;
	int status;