patch-2.2.18 linux/drivers/usb/serial/digi_acceleport.c

• Lines: 2073
• Date: Thu Dec 7 14:52:03 2000
• Orig file: v2.2.17/drivers/usb/serial/digi_acceleport.c
• Orig date: Thu Jan 1 01:00:00 1970

diff -u --new-file --recursive --exclude-from /usr/src/exclude v2.2.17/drivers/usb/serial/digi_acceleport.c linux/drivers/usb/serial/digi_acceleport.c
@@ -0,0 +1,2072 @@
+/*
+*  Digi AccelePort USB-4 and USB-2 Serial Converters
+*
+*  Copyright 2000 by Digi International
+*
+*  This program is free software; you can redistribute it and/or modify
+*  it under the terms of the GNU General Public License as published by
+*  the Free Software Foundation; either version 2 of the License, or
+*  (at your option) any later version.
+*
+*  Shamelessly based on Brian Warner's keyspan_pda.c and Greg Kroah-Hartman's
+*  usb-serial driver.
+*
+*  Peter Berger (pberger@brimson.com)
+*  Al Borchers (borchers@steinerpoint.com)
+*
+* (11/01/2000) pberger and borchers
+*    -- Turned off the USB_DISABLE_SPD flag for write bulk urbs--it caused
+*       USB 4 ports to hang on startup.
+*    -- Serialized access to write urbs by adding the dp_write_urb_in_use
+*       flag; otherwise, the driver caused SMP system hangs.  Watching the
+*       urb status is not sufficient.
+*
+* (10/05/2000) gkh
+*    -- Fixed bug with urb->dev not being set properly, now that the usb
+*       core needs it.
+* 
+*  (8/8/2000) pberger and borchers
+*    -- Fixed close so that 
+*       - it can timeout while waiting for transmit idle, if needed;
+*       - it ignores interrupts when flushing the port, turning
+*         of modem signalling, and so on;
+*       - it waits for the flush to really complete before returning.
+*    -- Read_bulk_callback and write_bulk_callback check for a closed
+*       port before using the tty struct or writing to the port.
+*    -- The two changes above fix the oops caused by interrupted closes.
+*    -- Added interruptible args to write_oob_command and set_modem_signals
+*       and added a timeout arg to transmit_idle; needed for fixes to
+*       close.
+*    -- Added code for rx_throttle and rx_unthrottle so that input flow
+*       control works.
+*    -- Added code to set overrun, parity, framing, and break errors
+*       (untested).
+*    -- Set USB_DISABLE_SPD flag for write bulk urbs, so no 0 length
+*       bulk writes are done.  These hung the Digi USB device.  The
+*       0 length bulk writes were a new feature of usb-uhci added in
+*       the 2.4.0-test6 kernels.
+*    -- Fixed mod inc race in open; do mod inc before sleeping to wait
+*       for a close to finish.
+*
+*  (7/31/2000) pberger
+*    -- Fixed bugs with hardware handshaking:
+*       - Added code to set/clear tty->hw_stopped in digi_read_oob_callback()
+*         and digi_set_termios()
+*    -- Added code in digi_set_termios() to
+*       - add conditional in code handling transition from B0 to only
+*         set RTS if RTS/CTS flow control is either not in use or if
+*         the port is not currently throttled.
+*       - handle turning off CRTSCTS.
+*
+*  (7/30/2000) borchers
+*    -- Added support for more than one Digi USB device by moving
+*       globals to a private structure in the pointed to from the
+*       usb_serial structure.
+*    -- Moved the modem change and transmit idle wait queues into
+*       the port private structure, so each port has its own queue
+*       rather than sharing global queues.
+*    -- Added support for break signals.
+*
+*  (7/25/2000) pberger
+*    -- Added USB-2 support.  Note: the USB-2 supports 3 devices: two
+*       serial and a parallel port.  The parallel port is implemented
+*       as a serial-to-parallel converter.  That is, the driver actually
+*       presents all three USB-2 interfaces as serial ports, but the third
+*       one physically connects to a parallel device.  Thus, for example,
+*       one could plug a parallel printer into the USB-2's third port,
+*       but from the kernel's (and userland's) point of view what's
+*       actually out there is a serial device.
+*
+*  (7/15/2000) borchers
+*    -- Fixed race in open when a close is in progress.
+*    -- Keep count of opens and dec the module use count for each
+*       outstanding open when shutdown is called (on disconnect).
+*    -- Fixed sanity checks in read_bulk_callback and write_bulk_callback
+*       so pointers are checked before use.
+*    -- Split read bulk callback into in band and out of band
+*       callbacks, and no longer restart read chains if there is
+*       a status error or a sanity error.  This fixed the seg
+*       faults and other errors we used to get on disconnect.
+*    -- Port->active is once again a flag as usb-serial intended it
+*       to be, not a count.  Since it was only a char it would
+*       have been limited to 256 simultaneous opens.  Now the open
+*       count is kept in the port private structure in dp_open_count.
+*    -- Added code for modularization of the digi_acceleport driver.
+*
+*  (6/27/2000) pberger and borchers
+*    -- Zeroed out sync field in the wakeup_task before first use;
+*       otherwise the uninitialized value might prevent the task from
+*       being scheduled.
+*    -- Initialized ret value to 0 in write_bulk_callback, otherwise
+*       the uninitialized value could cause a spurious debugging message.
+*
+*  (6/22/2000) pberger and borchers
+*    -- Made cond_wait_... inline--apparently on SPARC the flags arg
+*       to spin_lock_irqsave cannot be passed to another function
+*       to call spin_unlock_irqrestore.  Thanks to Pauline Middelink.
+*    -- In digi_set_modem_signals the inner nested spin locks use just
+*       spin_lock() rather than spin_lock_irqsave().  The old code
+*       mistakenly left interrupts off.  Thanks to Pauline Middelink.
+*    -- copy_from_user (which can sleep) is no longer called while a
+*       spinlock is held.  We copy to a local buffer before getting
+*       the spinlock--don't like the extra copy but the code is simpler.
+*    -- Printk and dbg are no longer called while a spin lock is held.
+*
+*  (6/4/2000) pberger and borchers
+*    -- Replaced separate calls to spin_unlock_irqrestore and
+*       interruptible_sleep_on_timeout with a new function
+*       cond_wait_interruptible_timeout_irqrestore.  This eliminates
+*       the race condition where the wake up could happen after
+*       the unlock and before the sleep.
+*    -- Close now waits for output to drain.
+*    -- Open waits until any close in progress is finished.
+*    -- All out of band responses are now processed, not just the
+*       first in a USB packet.
+*    -- Fixed a bug that prevented the driver from working when the
+*       first Digi port was not the first USB serial port--the driver
+*       was mistakenly using the external USB serial port number to
+*       try to index into its internal ports.
+*    -- Fixed an SMP bug -- write_bulk_callback is called directly from
+*       an interrupt, so spin_lock_irqsave/spin_unlock_irqrestore are
+*       needed for locks outside write_bulk_callback that are also
+*       acquired by write_bulk_callback to prevent deadlocks.
+*    -- Fixed support for select() by making digi_chars_in_buffer()
+*       return 256 when -EINPROGRESS is set, as the line discipline
+*       code in n_tty.c expects.
+*    -- Fixed an include file ordering problem that prevented debugging
+*       messages from working.
+*    -- Fixed an intermittent timeout problem that caused writes to
+*       sometimes get stuck on some machines on some kernels.  It turns
+*       out in these circumstances write_chan() (in n_tty.c) was
+*       asleep waiting for our wakeup call.  Even though we call
+*       wake_up_interruptible() in digi_write_bulk_callback(), there is
+*       a race condition that could cause the wakeup to fail: if our
+*       wake_up_interruptible() call occurs between the time that our
+*       driver write routine finishes and write_chan() sets current->state
+*       to TASK_INTERRUPTIBLE, the effect of our wakeup setting the state
+*       to TASK_RUNNING will be lost and write_chan's subsequent call to
+*       schedule() will never return (unless it catches a signal).
+*       This race condition occurs because write_bulk_callback() (and thus
+*       the wakeup) are called asynchonously from an interrupt, rather than
+*       from the scheduler.  We can avoid the race by calling the wakeup
+*       from the scheduler queue and that's our fix:  Now, at the end of
+*       write_bulk_callback() we queue up a wakeup call on the scheduler
+*       task queue.  We still also invoke the wakeup directly since that
+*       squeezes a bit more performance out of the driver, and any lost
+*       race conditions will get cleaned up at the next scheduler run.
+*
+*       NOTE:  The problem also goes away if you comment out
+*       the two code lines in write_chan() where current->state
+*       is set to TASK_RUNNING just before calling driver.write() and to
+*       TASK_INTERRUPTIBLE immediately afterwards.  This is why the
+*       problem did not show up with the 2.2 kernels -- they do not
+*       include that code.
+*
+*  (5/16/2000) pberger and borchers
+*    -- Added timeouts to sleeps, to defend against lost wake ups.
+*    -- Handle transition to/from B0 baud rate in digi_set_termios.
+*
+*  (5/13/2000) pberger and borchers
+*    -- All commands now sent on out of band port, using
+*       digi_write_oob_command.
+*    -- Get modem control signals whenever they change, support TIOCMGET/
+*       SET/BIS/BIC ioctls.
+*    -- digi_set_termios now supports parity, word size, stop bits, and
+*       receive enable.
+*    -- Cleaned up open and close, use digi_set_termios and
+*       digi_write_oob_command to set port parameters.
+*    -- Added digi_startup_device to start read chains on all ports.
+*    -- Write buffer is only used when count==1, to be sure put_char can
+*       write a char (unless the buffer is full).
+*
+*  (5/10/2000) pberger and borchers
+*    -- Added MOD_INC_USE_COUNT/MOD_DEC_USE_COUNT calls on open/close.
+*    -- Fixed problem where the first incoming character is lost on
+*       port opens after the first close on that port.  Now we keep
+*       the read_urb chain open until shutdown.
+*    -- Added more port conditioning calls in digi_open and digi_close.
+*    -- Convert port->active to a use count so that we can deal with multiple
+*       opens and closes properly.
+*    -- Fixed some problems with the locking code.
+*
+*  (5/3/2000) pberger and borchers
+*    -- First alpha version of the driver--many known limitations and bugs.
+*
+*
+*  Locking and SMP
+*
+*  - Each port, including the out-of-band port, has a lock used to
+*    serialize all access to the port's private structure.
+*  - The port lock is also used to serialize all writes and access to
+*    the port's URB.
+*  - The port lock is also used for the port write_wait condition
+*    variable.  Holding the port lock will prevent a wake up on the
+*    port's write_wait; this can be used with cond_wait_... to be sure
+*    the wake up is not lost in a race when dropping the lock and
+*    sleeping waiting for the wakeup.
+*  - digi_write() does not sleep, since it is sometimes called on
+*    interrupt time.
+*  - digi_write_bulk_callback() and digi_read_bulk_callback() are
+*    called directly from interrupts.  Hence spin_lock_irqsave()
+*    and spin_lock_irqrestore() are used in the rest of the code
+*    for any locks they acquire.
+*  - digi_write_bulk_callback() gets the port lock before waking up
+*    processes sleeping on the port write_wait.  It also schedules
+*    wake ups so they happen from the scheduler, because the tty
+*    system can miss wake ups from interrupts.
+*  - All sleeps use a timeout of DIGI_RETRY_TIMEOUT before looping to
+*    recheck the condition they are sleeping on.  This is defensive,
+*    in case a wake up is lost.
+*  - Following Documentation/DocBook/kernel-locking.pdf no spin locks
+*    are held when calling copy_to/from_user or printk.
+*    
+*  $Id: digi_acceleport.c,v 1.80.1.2 2000/11/02 05:45:08 root Exp $
+*/
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/poll.h>
+#include <linux/init.h>
+#include <linux/malloc.h>
+#include <linux/fcntl.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/tty.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/tqueue.h>
+
+#ifdef CONFIG_USB_SERIAL_DEBUG
+	#define DEBUG
+#else
+	#undef DEBUG
+#endif
+
+#include <linux/usb.h>
+#include "usb-serial.h"
+
+
+/* Defines */
+
+/* port output buffer length -- must be <= transfer buffer length - 2 */
+/* so we can be sure to send the full buffer in one urb */
+#define DIGI_OUT_BUF_SIZE		8
+
+/* port input buffer length -- must be >= transfer buffer length - 3 */
+/* so we can be sure to hold at least one full buffer from one urb */
+#define DIGI_IN_BUF_SIZE		64
+
+/* retry timeout while sleeping */
+#define DIGI_RETRY_TIMEOUT		(HZ/10)
+
+/* timeout while waiting for tty output to drain in close */
+/* this delay is used twice in close, so the total delay could */
+/* be twice this value */
+#define DIGI_CLOSE_TIMEOUT		(5*HZ)
+
+
+/* AccelePort USB Defines */
+
+/* ids */
+#define DIGI_VENDOR_ID			0x05c5
+#define DIGI_2_ID			0x0002	/* USB-2 */
+#define DIGI_4_ID			0x0004	/* USB-4 */
+
+/* commands
+ * "INB": can be used on the in-band endpoint
+ * "OOB": can be used on the out-of-band endpoint
+ */
+#define DIGI_CMD_SET_BAUD_RATE			0	/* INB, OOB */
+#define DIGI_CMD_SET_WORD_SIZE			1	/* INB, OOB */
+#define DIGI_CMD_SET_PARITY			2	/* INB, OOB */
+#define DIGI_CMD_SET_STOP_BITS			3	/* INB, OOB */
+#define DIGI_CMD_SET_INPUT_FLOW_CONTROL		4	/* INB, OOB */
+#define DIGI_CMD_SET_OUTPUT_FLOW_CONTROL	5	/* INB, OOB */
+#define DIGI_CMD_SET_DTR_SIGNAL			6	/* INB, OOB */
+#define DIGI_CMD_SET_RTS_SIGNAL			7	/* INB, OOB */
+#define DIGI_CMD_READ_INPUT_SIGNALS		8	/*      OOB */
+#define DIGI_CMD_IFLUSH_FIFO			9	/*      OOB */
+#define DIGI_CMD_RECEIVE_ENABLE			10	/* INB, OOB */
+#define DIGI_CMD_BREAK_CONTROL			11	/* INB, OOB */
+#define DIGI_CMD_LOCAL_LOOPBACK			12	/* INB, OOB */
+#define DIGI_CMD_TRANSMIT_IDLE			13	/* INB, OOB */
+#define DIGI_CMD_READ_UART_REGISTER		14	/*      OOB */
+#define DIGI_CMD_WRITE_UART_REGISTER		15	/* INB, OOB */
+#define DIGI_CMD_AND_UART_REGISTER		16	/* INB, OOB */
+#define DIGI_CMD_OR_UART_REGISTER		17	/* INB, OOB */
+#define DIGI_CMD_SEND_DATA			18	/* INB      */
+#define DIGI_CMD_RECEIVE_DATA			19	/* INB      */
+#define DIGI_CMD_RECEIVE_DISABLE		20	/* INB      */
+#define DIGI_CMD_GET_PORT_TYPE			21	/*      OOB */
+
+/* baud rates */
+#define DIGI_BAUD_50				0
+#define DIGI_BAUD_75				1
+#define DIGI_BAUD_110				2
+#define DIGI_BAUD_150				3
+#define DIGI_BAUD_200				4
+#define DIGI_BAUD_300				5
+#define DIGI_BAUD_600				6
+#define DIGI_BAUD_1200				7
+#define DIGI_BAUD_1800				8
+#define DIGI_BAUD_2400				9
+#define DIGI_BAUD_4800				10
+#define DIGI_BAUD_7200				11
+#define DIGI_BAUD_9600				12
+#define DIGI_BAUD_14400				13
+#define DIGI_BAUD_19200				14
+#define DIGI_BAUD_28800				15
+#define DIGI_BAUD_38400				16
+#define DIGI_BAUD_57600				17
+#define DIGI_BAUD_76800				18
+#define DIGI_BAUD_115200			19
+#define DIGI_BAUD_153600			20
+#define DIGI_BAUD_230400			21
+#define DIGI_BAUD_460800			22
+
+/* arguments */
+#define DIGI_WORD_SIZE_5			0
+#define DIGI_WORD_SIZE_6			1
+#define DIGI_WORD_SIZE_7			2
+#define DIGI_WORD_SIZE_8			3
+
+#define DIGI_PARITY_NONE			0
+#define DIGI_PARITY_ODD				1
+#define DIGI_PARITY_EVEN			2
+#define DIGI_PARITY_MARK			3
+#define DIGI_PARITY_SPACE			4
+
+#define DIGI_STOP_BITS_1			0
+#define DIGI_STOP_BITS_2			1
+
+#define DIGI_INPUT_FLOW_CONTROL_XON_XOFF	1
+#define DIGI_INPUT_FLOW_CONTROL_RTS		2
+#define DIGI_INPUT_FLOW_CONTROL_DTR		4
+
+#define DIGI_OUTPUT_FLOW_CONTROL_XON_XOFF	1
+#define DIGI_OUTPUT_FLOW_CONTROL_CTS		2
+#define DIGI_OUTPUT_FLOW_CONTROL_DSR		4
+
+#define DIGI_DTR_INACTIVE			0
+#define DIGI_DTR_ACTIVE				1
+#define DIGI_DTR_INPUT_FLOW_CONTROL		2
+
+#define DIGI_RTS_INACTIVE			0
+#define DIGI_RTS_ACTIVE				1
+#define DIGI_RTS_INPUT_FLOW_CONTROL		2
+#define DIGI_RTS_TOGGLE				3
+
+#define DIGI_FLUSH_TX				1
+#define DIGI_FLUSH_RX				2
+#define DIGI_RESUME_TX				4 /* clears xoff condition */
+
+#define DIGI_TRANSMIT_NOT_IDLE			0
+#define DIGI_TRANSMIT_IDLE			1
+
+#define DIGI_DISABLE				0
+#define DIGI_ENABLE				1
+
+#define DIGI_DEASSERT				0
+#define DIGI_ASSERT				1
+
+/* in band status codes */
+#define DIGI_OVERRUN_ERROR			4
+#define DIGI_PARITY_ERROR			8
+#define DIGI_FRAMING_ERROR			16
+#define DIGI_BREAK_ERROR			32
+
+/* out of band status */
+#define DIGI_NO_ERROR				0
+#define DIGI_BAD_FIRST_PARAMETER		1
+#define DIGI_BAD_SECOND_PARAMETER		2
+#define DIGI_INVALID_LINE			3
+#define DIGI_INVALID_OPCODE			4
+
+/* input signals */
+#define DIGI_READ_INPUT_SIGNALS_SLOT		1
+#define DIGI_READ_INPUT_SIGNALS_ERR		2
+#define DIGI_READ_INPUT_SIGNALS_BUSY		4
+#define DIGI_READ_INPUT_SIGNALS_PE		8
+#define DIGI_READ_INPUT_SIGNALS_CTS		16
+#define DIGI_READ_INPUT_SIGNALS_DSR		32
+#define DIGI_READ_INPUT_SIGNALS_RI		64
+#define DIGI_READ_INPUT_SIGNALS_DCD		128
+
+
+/* macros */
+#define MAX(a,b)	(((a)>(b))?(a):(b))
+#define MIN(a,b)	(((a)<(b))?(a):(b))
+
+
+/* Structures */
+
+typedef struct digi_serial {
+	spinlock_t ds_serial_lock;
+	struct usb_serial_port *ds_oob_port;	/* out-of-band port */
+	int ds_oob_port_num;			/* index of out-of-band port */
+	int ds_device_started;
+} digi_serial_t;
+
+typedef struct digi_port {
+	spinlock_t dp_port_lock;
+	int dp_port_num;
+	int dp_out_buf_len;
+	unsigned char dp_out_buf[DIGI_OUT_BUF_SIZE];
+	int dp_in_buf_len;
+	unsigned char dp_in_buf[DIGI_IN_BUF_SIZE];
+	unsigned char dp_in_flag_buf[DIGI_IN_BUF_SIZE];
+	int dp_write_urb_in_use;
+	unsigned int dp_modem_signals;
+	wait_queue_head_t dp_modem_change_wait;
+	int dp_open_count;			/* inc on open, dec on close */
+	int dp_transmit_idle;
+	wait_queue_head_t dp_transmit_idle_wait;
+	int dp_throttled;
+	int dp_throttle_restart;
+	wait_queue_head_t dp_flush_wait;
+	int dp_in_close;			/* close in progress */
+	wait_queue_head_t dp_close_wait;	/* wait queue for close */
+	struct tq_struct dp_wakeup_task;
+} digi_port_t;
+
+
+/* Local Function Declarations */
+
+static void digi_wakeup_write( struct usb_serial_port *port );
+static void digi_wakeup_write_lock( struct usb_serial_port *port );
+static int digi_write_oob_command( struct usb_serial_port *port,
+	unsigned char *buf, int count, int interruptible );
+static int digi_write_inb_command( struct usb_serial_port *port,
+	unsigned char *buf, int count, unsigned long timeout );
+static int digi_set_modem_signals( struct usb_serial_port *port,
+	unsigned int modem_signals, int interruptible );
+static int digi_transmit_idle( struct usb_serial_port *port,
+	unsigned long timeout );
+static void digi_rx_throttle (struct usb_serial_port *port);
+static void digi_rx_unthrottle (struct usb_serial_port *port);
+static void digi_set_termios( struct usb_serial_port *port, 
+	struct termios *old_termios );
+static void digi_break_ctl( struct usb_serial_port *port, int break_state );
+static int digi_ioctl( struct usb_serial_port *port, struct file *file,
+	unsigned int cmd, unsigned long arg );
+static int digi_write( struct usb_serial_port *port, int from_user,
+	const unsigned char *buf, int count );
+static void digi_write_bulk_callback( struct urb *urb );
+static int digi_write_room( struct usb_serial_port *port );
+static int digi_chars_in_buffer( struct usb_serial_port *port );
+static int digi_open( struct usb_serial_port *port, struct file *filp );
+static void digi_close( struct usb_serial_port *port, struct file *filp );
+static int digi_startup_device( struct usb_serial *serial );
+static int digi_startup( struct usb_serial *serial );
+static void digi_shutdown( struct usb_serial *serial );
+static void digi_read_bulk_callback( struct urb *urb );
+static int digi_read_inb_callback( struct urb *urb );
+static int digi_read_oob_callback( struct urb *urb );
+
+
+/* Statics */
+
+/* device info needed for the Digi serial converter */
+static u16 digi_vendor_id = DIGI_VENDOR_ID;
+static u16 digi_product_2_id = DIGI_2_ID;	/* USB 2 */
+static u16 digi_product_4_id = DIGI_4_ID;	/* USB 4 */
+
+static struct usb_serial_device_type digi_acceleport_2_device = {
+	name:				"Digi USB",
+	idVendor:			&digi_vendor_id,
+	idProduct:			&digi_product_2_id,
+	needs_interrupt_in:		DONT_CARE,
+	needs_bulk_in:			MUST_HAVE,
+	needs_bulk_out:			MUST_HAVE,
+	num_interrupt_in:		0,
+	num_bulk_in:			4,
+	num_bulk_out:			4,
+	num_ports:			3,
+	open:				digi_open,
+	close:				digi_close,
+	write:				digi_write,
+	write_room:			digi_write_room,
+	write_bulk_callback: 		digi_write_bulk_callback,
+	read_bulk_callback:		digi_read_bulk_callback,
+	chars_in_buffer:		digi_chars_in_buffer,
+	throttle:			digi_rx_throttle,
+	unthrottle:			digi_rx_unthrottle,
+	ioctl:				digi_ioctl,
+	set_termios:			digi_set_termios,
+	break_ctl:			digi_break_ctl,
+	startup:			digi_startup,
+	shutdown:			digi_shutdown,
+};
+
+static struct usb_serial_device_type digi_acceleport_4_device = {
+	name:				"Digi USB",
+	idVendor:			&digi_vendor_id,
+	idProduct:			&digi_product_4_id,
+	needs_interrupt_in:		DONT_CARE,
+	needs_bulk_in:			MUST_HAVE,
+	needs_bulk_out:			MUST_HAVE,
+	num_interrupt_in:		0,
+	num_bulk_in:			5,
+	num_bulk_out:			5,
+	num_ports:			4,
+	open:				digi_open,
+	close:				digi_close,
+	write:				digi_write,
+	write_room:			digi_write_room,
+	write_bulk_callback: 		digi_write_bulk_callback,
+	read_bulk_callback:		digi_read_bulk_callback,
+	chars_in_buffer:		digi_chars_in_buffer,
+	throttle:			digi_rx_throttle,
+	unthrottle:			digi_rx_unthrottle,
+	ioctl:				digi_ioctl,
+	set_termios:			digi_set_termios,
+	break_ctl:			digi_break_ctl,
+	startup:			digi_startup,
+	shutdown:			digi_shutdown,
+};
+
+
+/* Functions */
+
+/*
+*  Cond Wait Interruptible Timeout Irqrestore
+*
+*  Do spin_unlock_irqrestore and interruptible_sleep_on_timeout
+*  so that wake ups are not lost if they occur between the unlock
+*  and the sleep.  In other words, spin_lock_irqrestore and
+*  interruptible_sleep_on_timeout are "atomic" with respect to
+*  wake ups.  This is used to implement condition variables.
+*/
+
+static inline long cond_wait_interruptible_timeout_irqrestore(
+	wait_queue_head_t *q, long timeout,
+	spinlock_t *lock, unsigned long flags )
+{
+
+	wait_queue_t wait;
+
+
+	init_waitqueue_entry( &wait, current );
+
+	set_current_state( TASK_INTERRUPTIBLE );
+
+	add_wait_queue( q, &wait );
+
+	spin_unlock_irqrestore( lock, flags );
+
+	timeout = schedule_timeout(timeout);
+
+	set_current_state( TASK_RUNNING );
+
+	remove_wait_queue( q, &wait );
+
+	return( timeout );
+
+}
+
+
+/*
+*  Digi Wakeup Write
+*
+*  Wake up port, line discipline, and tty processes sleeping
+*  on writes.
+*/
+
+static void digi_wakeup_write_lock( struct usb_serial_port *port )
+{
+
+	unsigned long flags;
+	digi_port_t *priv = (digi_port_t *)(port->private);
+
+
+	spin_lock_irqsave( &priv->dp_port_lock, flags );
+	digi_wakeup_write( port );
+	spin_unlock_irqrestore( &priv->dp_port_lock, flags );
+
+}
+
+static void digi_wakeup_write( struct usb_serial_port *port )
+{
+
+	struct tty_struct *tty = port->tty;
+
+
+	/* wake up port processes */
+	wake_up_interruptible( &port->write_wait );
+
+	/* wake up line discipline */
+	if( (tty->flags & (1 << TTY_DO_WRITE_WAKEUP))
+	&& tty->ldisc.write_wakeup )
+		(tty->ldisc.write_wakeup)(tty);
+
+	/* wake up other tty processes */
+	wake_up_interruptible( &tty->write_wait );
+	wake_up_interruptible( &tty->poll_wait ); /* For 2.2.x backport */
+
+}
+
+
+/*
+*  Digi Write OOB Command
+*
+*  Write commands on the out of band port.  Commands are 4
+*  bytes each, multiple commands can be sent at once, and
+*  no command will be split across USB packets.  Returns 0
+*  if successful, -EINTR if interrupted while sleeping and
+*  the interruptible flag is true, or a negative error
+*  returned by usb_submit_urb.
+*/
+
+static int digi_write_oob_command( struct usb_serial_port *port,
+	unsigned char *buf, int count, int interruptible )
+{
+
+	int ret = 0;
+	int len;
+	struct usb_serial_port *oob_port = (struct usb_serial_port *)((digi_serial_t *)port->serial->private)->ds_oob_port;
+	digi_port_t *oob_priv = (digi_port_t *)oob_port->private;
+	unsigned long flags = 0;
+
+
+dbg( "digi_write_oob_command: TOP: port=%d, count=%d", oob_priv->dp_port_num, count );
+
+	spin_lock_irqsave( &oob_priv->dp_port_lock, flags );
+
+	while( count > 0 ) {
+
+		while( oob_port->write_urb->status == -EINPROGRESS
+		|| oob_priv->dp_write_urb_in_use ) {
+			cond_wait_interruptible_timeout_irqrestore(
+				&oob_port->write_wait, DIGI_RETRY_TIMEOUT,
+				&oob_priv->dp_port_lock, flags );
+			if( interruptible && signal_pending(current) ) {
+				return( -EINTR );
+			}
+			spin_lock_irqsave( &oob_priv->dp_port_lock, flags );
+		}
+
+		/* len must be a multiple of 4, so commands are not split */
+		len = MIN( count, oob_port->bulk_out_size );
+		if( len > 4 )
+			len &= ~3;
+
+		memcpy( oob_port->write_urb->transfer_buffer, buf, len );
+		oob_port->write_urb->transfer_buffer_length = len;
+		oob_port->write_urb->dev = port->serial->dev;
+
+		if( (ret=usb_submit_urb(oob_port->write_urb)) == 0 ) {
+			oob_priv->dp_write_urb_in_use = 1;
+			count -= len;
+			buf += len;
+		}
+
+	}
+
+	spin_unlock_irqrestore( &oob_priv->dp_port_lock, flags );
+
+	if( ret ) {
+		err( __FUNCTION__ ": usb_submit_urb failed, ret=%d",
+			ret );
+	}
+
+	return( ret );
+
+}
+
+
+/*
+*  Digi Write In Band Command
+*
+*  Write commands on the given port.  Commands are 4
+*  bytes each, multiple commands can be sent at once, and
+*  no command will be split across USB packets.  If timeout
+*  is non-zero, write in band command will return after
+*  waiting unsuccessfully for the URB status to clear for
+*  timeout ticks.  Returns 0 if successful, or a negative
+*  error returned by digi_write.
+*/
+
+static int digi_write_inb_command( struct usb_serial_port *port,
+	unsigned char *buf, int count, unsigned long timeout )
+{
+
+	int ret = 0;
+	int len;
+	digi_port_t *priv = (digi_port_t *)(port->private);
+	unsigned char *data = port->write_urb->transfer_buffer;
+	unsigned long flags = 0;
+
+
+dbg( "digi_write_inb_command: TOP: port=%d, count=%d", priv->dp_port_num,
+count );
+
+	if( timeout )
+		timeout += jiffies;
+	else
+		timeout = ULONG_MAX;
+
+	spin_lock_irqsave( &priv->dp_port_lock, flags );
+
+	while( count > 0 && ret == 0 ) {
+
+		while( (port->write_urb->status == -EINPROGRESS
+		|| priv->dp_write_urb_in_use) && jiffies < timeout ) {
+			cond_wait_interruptible_timeout_irqrestore(
+				&port->write_wait, DIGI_RETRY_TIMEOUT,
+				&priv->dp_port_lock, flags );
+			if( signal_pending(current) ) {
+				return( -EINTR );
+			}
+			spin_lock_irqsave( &priv->dp_port_lock, flags );
+		}
+
+		/* len must be a multiple of 4 and small enough to */
+		/* guarantee the write will send buffered data first, */
+		/* so commands are in order with data and not split */
+		len = MIN( count, port->bulk_out_size-2-priv->dp_out_buf_len );
+		if( len > 4 )
+			len &= ~3;
+
+		/* write any buffered data first */
+		if( priv->dp_out_buf_len > 0 ) {
+			data[0] = DIGI_CMD_SEND_DATA;
+			data[1] = priv->dp_out_buf_len;
+			memcpy( data+2, priv->dp_out_buf,
+				priv->dp_out_buf_len );
+			memcpy( data+2+priv->dp_out_buf_len, buf, len );
+			port->write_urb->transfer_buffer_length
+				= priv->dp_out_buf_len+2+len;
+		} else {
+			memcpy( data, buf, len );
+			port->write_urb->transfer_buffer_length = len;
+		}
+		port->write_urb->dev = port->serial->dev;
+
+		if( (ret=usb_submit_urb(port->write_urb)) == 0 ) {
+			priv->dp_write_urb_in_use = 1;
+			priv->dp_out_buf_len = 0;
+			count -= len;
+			buf += len;
+		}
+
+	}
+
+	spin_unlock_irqrestore( &priv->dp_port_lock, flags );
+
+	if( ret ) {
+		err( __FUNCTION__ ": usb_submit_urb failed, ret=%d, port=%d",
+		ret, priv->dp_port_num );
+	}
+
+	return( ret );
+
+}
+
+
+/*
+*  Digi Set Modem Signals
+*
+*  Sets or clears DTR and RTS on the port, according to the
+*  modem_signals argument.  Use TIOCM_DTR and TIOCM_RTS flags
+*  for the modem_signals argument.  Returns 0 if successful,
+*  -EINTR if interrupted while sleeping, or a non-zero error
+*  returned by usb_submit_urb.
+*/
+
+static int digi_set_modem_signals( struct usb_serial_port *port,
+	unsigned int modem_signals, int interruptible )
+{
+
+	int ret;
+	digi_port_t *port_priv = (digi_port_t *)port->private;
+	struct usb_serial_port *oob_port = (struct usb_serial_port *)((digi_serial_t *)port->serial->private)->ds_oob_port;
+	digi_port_t *oob_priv = (digi_port_t *)oob_port->private;
+	unsigned char *data = oob_port->write_urb->transfer_buffer;
+	unsigned long flags = 0;
+
+
+dbg( "digi_set_modem_signals: TOP: port=%d, modem_signals=0x%x",
+port_priv->dp_port_num, modem_signals );
+
+	spin_lock_irqsave( &oob_priv->dp_port_lock, flags );
+	spin_lock( &port_priv->dp_port_lock );
+
+	while( oob_port->write_urb->status == -EINPROGRESS
+	|| oob_priv->dp_write_urb_in_use ) {
+		spin_unlock( &port_priv->dp_port_lock );
+		cond_wait_interruptible_timeout_irqrestore(
+			&oob_port->write_wait, DIGI_RETRY_TIMEOUT,
+			&oob_priv->dp_port_lock, flags );
+		if( interruptible && signal_pending(current) ) {
+			return( -EINTR );
+		}
+		spin_lock_irqsave( &oob_priv->dp_port_lock, flags );
+		spin_lock( &port_priv->dp_port_lock );
+	}
+
+	data[0] = DIGI_CMD_SET_DTR_SIGNAL;
+	data[1] = port_priv->dp_port_num;
+	data[2] = (modem_signals&TIOCM_DTR) ?
+		DIGI_DTR_ACTIVE : DIGI_DTR_INACTIVE;
+	data[3] = 0;
+
+	data[4] = DIGI_CMD_SET_RTS_SIGNAL;
+	data[5] = port_priv->dp_port_num;
+	data[6] = (modem_signals&TIOCM_RTS) ?
+		DIGI_RTS_ACTIVE : DIGI_RTS_INACTIVE;
+	data[7] = 0;
+
+	oob_port->write_urb->transfer_buffer_length = 8;
+	oob_port->write_urb->dev = port->serial->dev;
+
+	if( (ret=usb_submit_urb(oob_port->write_urb)) == 0 ) {
+		oob_priv->dp_write_urb_in_use = 1;
+		port_priv->dp_modem_signals =
+			(port_priv->dp_modem_signals&~(TIOCM_DTR|TIOCM_RTS))
+			| (modem_signals&(TIOCM_DTR|TIOCM_RTS));
+	}
+
+	spin_unlock( &port_priv->dp_port_lock );
+	spin_unlock_irqrestore( &oob_priv->dp_port_lock, flags );
+
+	if( ret ) {
+		err( __FUNCTION__ ": usb_submit_urb failed, ret=%d",
+		ret );
+	}
+
+	return( ret );
+
+}
+
+
+/*
+*  Digi Transmit Idle
+*
+*  Digi transmit idle waits, up to timeout ticks, for the transmitter
+*  to go idle.  It returns 0 if successful or a negative error.
+*
+*  There are race conditions here if more than one process is calling
+*  digi_transmit_idle on the same port at the same time.  However, this
+*  is only called from close, and only one process can be in close on a
+*  port at a time, so its ok.
+*/
+
+static int digi_transmit_idle( struct usb_serial_port *port,
+	unsigned long timeout )
+{
+
+	int ret;
+	unsigned char buf[2];
+	digi_port_t *priv = (digi_port_t *)(port->private);
+	unsigned long flags = 0;
+
+
+	spin_lock_irqsave( &priv->dp_port_lock, flags );
+	priv->dp_transmit_idle = 0;
+	spin_unlock_irqrestore( &priv->dp_port_lock, flags );
+
+	buf[0] = DIGI_CMD_TRANSMIT_IDLE;
+	buf[1] = 0;
+
+	timeout += jiffies;
+
+	if( (ret=digi_write_inb_command( port, buf, 2, timeout-jiffies )) != 0 )
+		return( ret );
+
+	spin_lock_irqsave( &priv->dp_port_lock, flags );
+
+	while( jiffies < timeout && !priv->dp_transmit_idle ) {
+		cond_wait_interruptible_timeout_irqrestore(
+			&priv->dp_transmit_idle_wait, DIGI_RETRY_TIMEOUT,
+			&priv->dp_port_lock, flags );
+		if( signal_pending(current) ) {
+			return( -EINTR );
+		}
+		spin_lock_irqsave( &priv->dp_port_lock, flags );
+	}
+
+	priv->dp_transmit_idle = 0;
+	spin_unlock_irqrestore( &priv->dp_port_lock, flags );
+
+	return( 0 );
+
+}
+
+
+static void digi_rx_throttle( struct usb_serial_port *port )
+{
+
+	unsigned long flags;
+	digi_port_t *priv = (digi_port_t *)(port->private);
+
+
+dbg( "digi_rx_throttle: TOP: port=%d", priv->dp_port_num );
+
+	/* stop receiving characters by not resubmitting the read urb */
+	spin_lock_irqsave( &priv->dp_port_lock, flags );
+	priv->dp_throttled = 1;
+	priv->dp_throttle_restart = 0;
+	priv->dp_in_buf_len = 0;
+	spin_unlock_irqrestore( &priv->dp_port_lock, flags );
+
+}
+
+
+static void digi_rx_unthrottle( struct usb_serial_port *port )
+{
+
+	int ret = 0;
+	int len;
+	unsigned long flags;
+	digi_port_t *priv = (digi_port_t *)(port->private);
+	struct tty_struct *tty = port->tty;
+
+
+dbg( "digi_rx_unthrottle: TOP: port=%d", priv->dp_port_num );
+
+	spin_lock_irqsave( &priv->dp_port_lock, flags );
+
+	/* send any buffered chars from throttle time on to tty subsystem */
+	len = MIN( priv->dp_in_buf_len, TTY_FLIPBUF_SIZE - tty->flip.count );
+	if( len > 0 ) {
+		memcpy( tty->flip.char_buf_ptr, priv->dp_in_buf, len );
+		memcpy( tty->flip.flag_buf_ptr, priv->dp_in_flag_buf, len );
+		tty->flip.char_buf_ptr += len;
+		tty->flip.flag_buf_ptr += len;
+		tty->flip.count += len;
+		tty_flip_buffer_push( tty );
+	}
+
+	/* restart read chain */
+	if( priv->dp_throttle_restart ) {
+		port->read_urb->dev = port->serial->dev;
+		ret = usb_submit_urb( port->read_urb );
+	}
+
+	/* turn throttle off */
+	priv->dp_throttled = 0;
+	priv->dp_in_buf_len = 0;
+	priv->dp_throttle_restart = 0;
+
+	spin_unlock_irqrestore( &priv->dp_port_lock, flags );
+
+	if( ret ) {
+		err( __FUNCTION__ ": usb_submit_urb failed, ret=%d, port=%d",
+			ret, priv->dp_port_num );
+	}
+
+}
+
+
+static void digi_set_termios( struct usb_serial_port *port, 
+	struct termios *old_termios )
+{
+
+	digi_port_t *priv = (digi_port_t *)(port->private);
+	unsigned int iflag = port->tty->termios->c_iflag;
+	unsigned int cflag = port->tty->termios->c_cflag;
+	unsigned int old_iflag = old_termios->c_iflag;
+	unsigned int old_cflag = old_termios->c_cflag;
+	unsigned char buf[32];
+	unsigned int modem_signals;
+	int arg,ret;
+	int i = 0;
+
+
+dbg( "digi_set_termios: TOP: port=%d, iflag=0x%x, old_iflag=0x%x, cflag=0x%x, old_cflag=0x%x", priv->dp_port_num, iflag, old_iflag, cflag, old_cflag );
+
+	/* set baud rate */
+	if( (cflag&CBAUD) != (old_cflag&CBAUD) ) {
+
+		arg = -1;
+
+		/* reassert DTR and (maybe) RTS on transition from B0 */
+		if( (old_cflag&CBAUD) == B0 ) {
+			/* don't set RTS if using hardware flow control */
+			/* and throttling input */
+			modem_signals = TIOCM_DTR;
+			if( !(port->tty->termios->c_cflag & CRTSCTS) ||
+			!test_bit(TTY_THROTTLED, &port->tty->flags) ) {
+				modem_signals |= TIOCM_RTS;
+			}
+			digi_set_modem_signals( port, modem_signals, 1 );
+		}
+
+		switch( (cflag&CBAUD) ) {
+			/* drop DTR and RTS on transition to B0 */
+		case B0: digi_set_modem_signals( port, 0, 1 ); break;
+		case B50: arg = DIGI_BAUD_50; break;
+		case B75: arg = DIGI_BAUD_75; break;
+		case B110: arg = DIGI_BAUD_110; break;
+		case B150: arg = DIGI_BAUD_150; break;
+		case B200: arg = DIGI_BAUD_200; break;
+		case B300: arg = DIGI_BAUD_300; break;
+		case B600: arg = DIGI_BAUD_600; break;
+		case B1200: arg = DIGI_BAUD_1200; break;
+		case B1800: arg = DIGI_BAUD_1800; break;
+		case B2400: arg = DIGI_BAUD_2400; break;
+		case B4800: arg = DIGI_BAUD_4800; break;
+		case B9600: arg = DIGI_BAUD_9600; break;
+		case B19200: arg = DIGI_BAUD_19200; break;
+		case B38400: arg = DIGI_BAUD_38400; break;
+		case B57600: arg = DIGI_BAUD_57600; break;
+		case B115200: arg = DIGI_BAUD_115200; break;
+		case B230400: arg = DIGI_BAUD_230400; break;
+		case B460800: arg = DIGI_BAUD_460800; break;
+		default:
+			dbg( "digi_set_termios: can't handle baud rate 0x%x",
+				(cflag&CBAUD) );
+			break;
+		}
+
+		if( arg != -1 ) {
+			buf[i++] = DIGI_CMD_SET_BAUD_RATE;
+			buf[i++] = priv->dp_port_num;
+			buf[i++] = arg;
+			buf[i++] = 0;
+		}
+
+	}
+
+	/* set parity */
+	if( (cflag&(PARENB|PARODD)) != (old_cflag&(PARENB|PARODD)) ) {
+
+		if( (cflag&PARENB) ) {
+			if( (cflag&PARODD) )
+				arg = DIGI_PARITY_ODD;
+			else
+				arg = DIGI_PARITY_EVEN;
+		} else {
+			arg = DIGI_PARITY_NONE;
+		}
+
+		buf[i++] = DIGI_CMD_SET_PARITY;
+		buf[i++] = priv->dp_port_num;
+		buf[i++] = arg;
+		buf[i++] = 0;
+
+	}
+
+	/* set word size */
+	if( (cflag&CSIZE) != (old_cflag&CSIZE) ) {
+
+		arg = -1;
+
+		switch( (cflag&CSIZE) ) {
+		case CS5: arg = DIGI_WORD_SIZE_5; break;
+		case CS6: arg = DIGI_WORD_SIZE_6; break;
+		case CS7: arg = DIGI_WORD_SIZE_7; break;
+		case CS8: arg = DIGI_WORD_SIZE_8; break;
+		default:
+			dbg( "digi_set_termios: can't handle word size %d",
+				(cflag&CSIZE) );
+			break;
+		}
+
+		if( arg != -1 ) {
+			buf[i++] = DIGI_CMD_SET_WORD_SIZE;
+			buf[i++] = priv->dp_port_num;
+			buf[i++] = arg;
+			buf[i++] = 0;
+		}
+
+	}
+
+	/* set stop bits */
+	if( (cflag&CSTOPB) != (old_cflag&CSTOPB) ) {
+
+		if( (cflag&CSTOPB) )
+			arg = DIGI_STOP_BITS_2;
+		else
+			arg = DIGI_STOP_BITS_1;
+
+		buf[i++] = DIGI_CMD_SET_STOP_BITS;
+		buf[i++] = priv->dp_port_num;
+		buf[i++] = arg;
+		buf[i++] = 0;
+
+	}
+
+	/* set input flow control */
+	if( (iflag&IXOFF) != (old_iflag&IXOFF)
+	|| (cflag&CRTSCTS) != (old_cflag&CRTSCTS) ) {
+
+		arg = 0;
+
+		if( (iflag&IXOFF) )
+			arg |= DIGI_INPUT_FLOW_CONTROL_XON_XOFF;
+		else
+			arg &= ~DIGI_INPUT_FLOW_CONTROL_XON_XOFF;
+
+		if( (cflag&CRTSCTS) ) {
+
+			arg |= DIGI_INPUT_FLOW_CONTROL_RTS;
+
+			/* On USB-4 it is necessary to assert RTS prior */
+			/* to selecting RTS input flow control.  */
+			buf[i++] = DIGI_CMD_SET_RTS_SIGNAL;
+			buf[i++] = priv->dp_port_num;
+			buf[i++] = DIGI_RTS_ACTIVE;
+			buf[i++] = 0;
+
+		} else {
+			arg &= ~DIGI_INPUT_FLOW_CONTROL_RTS;
+		}
+
+		buf[i++] = DIGI_CMD_SET_INPUT_FLOW_CONTROL;
+		buf[i++] = priv->dp_port_num;
+		buf[i++] = arg;
+		buf[i++] = 0;
+
+	}
+
+	/* set output flow control */
+	if( (iflag&IXON) != (old_iflag&IXON)
+	|| (cflag&CRTSCTS) != (old_cflag&CRTSCTS) ) {
+
+		arg = 0;
+
+		if( (iflag&IXON) )
+			arg |= DIGI_OUTPUT_FLOW_CONTROL_XON_XOFF;
+		else
+			arg &= ~DIGI_OUTPUT_FLOW_CONTROL_XON_XOFF;
+
+		if( (cflag&CRTSCTS) ) {
+			arg |= DIGI_OUTPUT_FLOW_CONTROL_CTS;
+		} else {
+			arg &= ~DIGI_OUTPUT_FLOW_CONTROL_CTS;
+			port->tty->hw_stopped = 0;
+		}
+
+		buf[i++] = DIGI_CMD_SET_OUTPUT_FLOW_CONTROL;
+		buf[i++] = priv->dp_port_num;
+		buf[i++] = arg;
+		buf[i++] = 0;
+
+	}
+
+	/* set receive enable/disable */
+	if( (cflag&CREAD) != (old_cflag&CREAD) ) {
+
+		if( (cflag&CREAD) )
+			arg = DIGI_ENABLE;
+		else
+			arg = DIGI_DISABLE;
+
+		buf[i++] = DIGI_CMD_RECEIVE_ENABLE;
+		buf[i++] = priv->dp_port_num;
+		buf[i++] = arg;
+		buf[i++] = 0;
+
+	}
+
+	if( (ret=digi_write_oob_command( port, buf, i, 1 )) != 0 )
+		dbg( "digi_set_termios: write oob failed, ret=%d", ret );
+
+}
+
+
+static void digi_break_ctl( struct usb_serial_port *port, int break_state )
+{
+
+	unsigned char buf[4];
+
+
+	buf[0] = DIGI_CMD_BREAK_CONTROL;
+	buf[1] = 2;				/* length */
+	buf[2] = break_state ? 1 : 0;
+	buf[3] = 0;				/* pad */
+
+	digi_write_inb_command( port, buf, 4, 0 );
+
+}
+
+
+static int digi_ioctl( struct usb_serial_port *port, struct file *file,
+	unsigned int cmd, unsigned long arg )
+{
+
+	digi_port_t *priv = (digi_port_t *)(port->private);
+	unsigned int val;
+	unsigned long flags = 0;
+
+
+dbg( "digi_ioctl: TOP: port=%d, cmd=0x%x", priv->dp_port_num, cmd );
+
+	switch (cmd) {
+
+	case TIOCMGET:
+		spin_lock_irqsave( &priv->dp_port_lock, flags );
+		val = priv->dp_modem_signals;
+		spin_unlock_irqrestore( &priv->dp_port_lock, flags );
+		if( copy_to_user((unsigned int *)arg, &val, sizeof(int)) )
+			return( -EFAULT );
+		return( 0 );
+
+	case TIOCMSET:
+	case TIOCMBIS:
+	case TIOCMBIC:
+		if( copy_from_user(&val, (unsigned int *)arg, sizeof(int)) )
+			return( -EFAULT );
+		spin_lock_irqsave( &priv->dp_port_lock, flags );
+		if( cmd == TIOCMBIS )
+			val = priv->dp_modem_signals | val;
+		else if( cmd == TIOCMBIC )
+			val = priv->dp_modem_signals & ~val;
+		spin_unlock_irqrestore( &priv->dp_port_lock, flags );
+		return( digi_set_modem_signals( port, val, 1 ) );
+
+	case TIOCMIWAIT:
+		/* wait for any of the 4 modem inputs (DCD,RI,DSR,CTS)*/
+		/* TODO */
+		return( 0 );
+
+	case TIOCGICOUNT:
+		/* return count of modemline transitions */
+		/* TODO */
+		return 0;
+
+	}
+
+	return( -ENOIOCTLCMD );
+
+}
+
+
+static int digi_write( struct usb_serial_port *port, int from_user,
+	const unsigned char *buf, int count )
+{
+
+	int ret,data_len,new_len;
+	digi_port_t *priv = (digi_port_t *)(port->private);
+	unsigned char *data = port->write_urb->transfer_buffer;
+	unsigned char user_buf[64];	/* 64 bytes is max USB bulk packet */
+	unsigned long flags = 0;
+
+
+dbg( "digi_write: TOP: port=%d, count=%d, from_user=%d, in_interrupt=%d",
+priv->dp_port_num, count, from_user, in_interrupt() );
+
+	/* copy user data (which can sleep) before getting spin lock */
+	count = MIN( 64, MIN( count, port->bulk_out_size-2 ) );
+	if( from_user && copy_from_user( user_buf, buf, count ) ) {
+		return( -EFAULT );
+	}
+
+	/* be sure only one write proceeds at a time */
+	/* there are races on the port private buffer */
+	/* and races to check write_urb->status */
+	spin_lock_irqsave( &priv->dp_port_lock, flags );
+
+	/* wait for urb status clear to submit another urb */
+	if( port->write_urb->status == -EINPROGRESS
+	|| priv->dp_write_urb_in_use ) {
+
+		/* buffer data if count is 1 (probably put_char) if possible */
+		if( count == 1 ) {
+			new_len = MIN( count,
+				DIGI_OUT_BUF_SIZE-priv->dp_out_buf_len );
+			memcpy( priv->dp_out_buf+priv->dp_out_buf_len, buf,
+				new_len );
+			priv->dp_out_buf_len += new_len;
+		} else {
+			new_len = 0;
+		}
+
+		spin_unlock_irqrestore( &priv->dp_port_lock, flags );
+
+		return( new_len );
+
+	}
+
+	/* allow space for any buffered data and for new data, up to */
+	/* transfer buffer size - 2 (for command and length bytes) */
+	new_len = MIN( count, port->bulk_out_size-2-priv->dp_out_buf_len );
+	data_len = new_len + priv->dp_out_buf_len;
+
+	if( data_len == 0 ) {
+		spin_unlock_irqrestore( &priv->dp_port_lock, flags );
+		return( 0 );
+	}
+
+	port->write_urb->transfer_buffer_length = data_len+2;
+	port->write_urb->dev = port->serial->dev;
+
+	*data++ = DIGI_CMD_SEND_DATA;
+	*data++ = data_len;
+
+	/* copy in buffered data first */
+	memcpy( data, priv->dp_out_buf, priv->dp_out_buf_len );
+	data += priv->dp_out_buf_len;
+
+	/* copy in new data */
+	memcpy( data, from_user ? user_buf : buf, new_len );
+
+	if( (ret=usb_submit_urb(port->write_urb)) == 0 ) {
+		priv->dp_write_urb_in_use = 1;
+		ret = new_len;
+		priv->dp_out_buf_len = 0;
+	}
+
+	/* return length of new data written, or error */
+	spin_unlock_irqrestore( &priv->dp_port_lock, flags );
+	if( ret < 0 ) {
+		err( __FUNCTION__ ": usb_submit_urb failed, ret=%d, port=%d",
+			ret, priv->dp_port_num );
+	}
+
+dbg( "digi_write: returning %d", ret );
+	return( ret );
+
+} 
+
+
+static void digi_write_bulk_callback( struct urb *urb )
+{
+
+	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
+	struct usb_serial *serial;
+	digi_port_t *priv;
+	int ret = 0;
+
+
+dbg( "digi_write_bulk_callback: TOP, urb->status=%d", urb->status );
+
+	/* port and serial sanity check */
+	if( port == NULL || (priv=(digi_port_t *)(port->private)) == NULL ) {
+		err( __FUNCTION__ ": port or port->private is NULL, status=%d",
+			urb->status );
+		return;
+	}
+	serial = port->serial;
+	if( serial == NULL || serial->private == NULL ) {
+		err( __FUNCTION__ ": serial or serial->private is NULL, status=%d", urb->status );
+		return;
+	}
+
+	/* handle oob callback */
+	if( priv->dp_port_num
+	== ((digi_serial_t *)(serial->private))->ds_oob_port_num ) {
+		dbg( "digi_write_bulk_callback: oob callback" );
+		spin_lock( &priv->dp_port_lock );
+		priv->dp_write_urb_in_use = 0;
+		wake_up_interruptible( &port->write_wait );
+		spin_unlock( &priv->dp_port_lock );
+		return;
+	}
+
+	/* further sanity checks */
+	if( port_paranoia_check( port, __FUNCTION__ )
+	|| serial_paranoia_check( serial, __FUNCTION__ ) )
+		return;
+
+	/* try to send any buffered data on this port, if it is open */
+	spin_lock( &priv->dp_port_lock );
+	priv->dp_write_urb_in_use = 0;
+	if( priv->dp_open_count && port->write_urb->status != -EINPROGRESS
+	&& priv->dp_out_buf_len > 0 ) {
+
+		*((unsigned char *)(port->write_urb->transfer_buffer))
+			= (unsigned char)DIGI_CMD_SEND_DATA;
+		*((unsigned char *)(port->write_urb->transfer_buffer)+1)
+			= (unsigned char)priv->dp_out_buf_len;
+
+		port->write_urb->transfer_buffer_length
+			= priv->dp_out_buf_len+2;
+		port->write_urb->dev = serial->dev;
+
+		memcpy( port->write_urb->transfer_buffer+2, priv->dp_out_buf,
+			priv->dp_out_buf_len );
+
+		if( (ret=usb_submit_urb(port->write_urb)) == 0 ) {
+			priv->dp_write_urb_in_use = 1;
+			priv->dp_out_buf_len = 0;
+		}
+
+	}
+
+	/* wake up processes sleeping on writes immediately */
+	digi_wakeup_write( port );
+
+	/* also queue up a wakeup at scheduler time, in case we */
+	/* lost the race in write_chan(). */
+	queue_task( &priv->dp_wakeup_task, &tq_scheduler );
+
+	spin_unlock( &priv->dp_port_lock );
+
+	if( ret ) {
+		err( __FUNCTION__ ": usb_submit_urb failed, ret=%d, port=%d",
+			ret, priv->dp_port_num );
+	}
+
+}
+
+
+static int digi_write_room( struct usb_serial_port *port )
+{
+
+	int room;
+	digi_port_t *priv = (digi_port_t *)(port->private);
+	unsigned long flags = 0;
+
+
+	spin_lock_irqsave( &priv->dp_port_lock, flags );
+
+	if( port->write_urb->status == -EINPROGRESS
+	|| priv->dp_write_urb_in_use )
+		room = 0;
+	else
+		room = port->bulk_out_size - 2 - priv->dp_out_buf_len;
+
+	spin_unlock_irqrestore( &priv->dp_port_lock, flags );
+
+dbg( "digi_write_room: port=%d, room=%d", priv->dp_port_num, room );
+	return( room );
+
+}
+
+
+static int digi_chars_in_buffer( struct usb_serial_port *port )
+{
+
+	digi_port_t *priv = (digi_port_t *)(port->private);
+
+
+	if( port->write_urb->status == -EINPROGRESS
+	|| priv->dp_write_urb_in_use ) {
+dbg( "digi_chars_in_buffer: port=%d, chars=%d", priv->dp_port_num, port->bulk_out_size - 2 );
+		/* return( port->bulk_out_size - 2 ); */
+		return( 256 );
+	} else {
+dbg( "digi_chars_in_buffer: port=%d, chars=%d", priv->dp_port_num, priv->dp_out_buf_len );
+		return( priv->dp_out_buf_len );
+	}
+
+}
+
+
+static int digi_open( struct usb_serial_port *port, struct file *filp )
+{
+
+	int ret;
+	unsigned char buf[32];
+	digi_port_t *priv = (digi_port_t *)(port->private);
+	struct termios not_termios;
+	unsigned long flags = 0;
+
+
+dbg( "digi_open: TOP: port=%d, active=%d, open_count=%d", priv->dp_port_num, port->active, priv->dp_open_count );
+
+	/* be sure the device is started up */
+	if( digi_startup_device( port->serial ) != 0 )
+		return( -ENXIO );
+
+	spin_lock_irqsave( &priv->dp_port_lock, flags );
+
+	/* don't wait on a close in progress for non-blocking opens */
+	if( priv->dp_in_close && (filp->f_flags&(O_NDELAY|O_NONBLOCK)) == 0 ) {
+		spin_unlock_irqrestore( &priv->dp_port_lock, flags );
+		return( -EAGAIN );
+	}
+
+	/* inc module use count before sleeping to wait for closes */
+	++priv->dp_open_count;
+	MOD_INC_USE_COUNT;
+
+	/* wait for a close in progress to finish */
+	while( priv->dp_in_close ) {
+		cond_wait_interruptible_timeout_irqrestore(
+			&priv->dp_close_wait, DIGI_RETRY_TIMEOUT,
+			&priv->dp_port_lock, flags );
+		if( signal_pending(current) ) {
+			--priv->dp_open_count;
+			MOD_DEC_USE_COUNT;
+			return( -EINTR );
+		}
+		spin_lock_irqsave( &priv->dp_port_lock, flags );
+	}
+
+	/* if port is already open, just return */
+	/* be sure exactly one open proceeds */
+	if( port->active ) {
+		spin_unlock_irqrestore( &priv->dp_port_lock, flags );
+		return( 0 );
+	}
+
+	/* first open, mark port as active */
+	port->active = 1;
+	spin_unlock_irqrestore( &priv->dp_port_lock, flags );
+ 
+	/* read modem signals automatically whenever they change */
+	buf[0] = DIGI_CMD_READ_INPUT_SIGNALS;
+	buf[1] = priv->dp_port_num;
+	buf[2] = DIGI_ENABLE;
+	buf[3] = 0;
+
+	/* flush fifos */
+	buf[4] = DIGI_CMD_IFLUSH_FIFO;
+	buf[5] = priv->dp_port_num;
+	buf[6] = DIGI_FLUSH_TX | DIGI_FLUSH_RX;
+	buf[7] = 0;
+
+	if( (ret=digi_write_oob_command( port, buf, 8, 1 )) != 0 )
+		dbg( "digi_open: write oob failed, ret=%d", ret );
+
+	/* set termios settings */
+	not_termios.c_cflag = ~port->tty->termios->c_cflag;
+	not_termios.c_iflag = ~port->tty->termios->c_iflag;
+	digi_set_termios( port, &not_termios );
+
+	/* set DTR and RTS */
+	digi_set_modem_signals( port, TIOCM_DTR|TIOCM_RTS, 1 );
+
+	return( 0 );
+
+}
+
+
+static void digi_close( struct usb_serial_port *port, struct file *filp )
+{
+
+	int ret;
+	unsigned char buf[32];
+	struct tty_struct *tty = port->tty;
+	digi_port_t *priv = (digi_port_t *)port->private;
+	unsigned long flags = 0;
+
+
+dbg( "digi_close: TOP: port=%d, active=%d, open_count=%d", priv->dp_port_num, port->active, priv->dp_open_count );
+
+
+	/* do cleanup only after final close on this port */
+	spin_lock_irqsave( &priv->dp_port_lock, flags );
+	if( priv->dp_open_count > 1 ) {
+		--priv->dp_open_count;
+		MOD_DEC_USE_COUNT;
+		spin_unlock_irqrestore( &priv->dp_port_lock, flags );
+		return;
+	} else if( priv->dp_open_count <= 0 ) {
+		spin_unlock_irqrestore( &priv->dp_port_lock, flags );
+		return;
+	}
+	priv->dp_in_close = 1;
+	spin_unlock_irqrestore( &priv->dp_port_lock, flags );
+
+	/* tell line discipline to process only XON/XOFF */
+        tty->closing = 1;
+
+	/* wait for output to drain */
+	if( (filp->f_flags&(O_NDELAY|O_NONBLOCK)) == 0 ) {
+		tty_wait_until_sent( tty, DIGI_CLOSE_TIMEOUT );
+	}
+
+	/* flush driver and line discipline buffers */
+	if( tty->driver.flush_buffer )
+		tty->driver.flush_buffer( tty );
+	if( tty->ldisc.flush_buffer )
+		tty->ldisc.flush_buffer( tty );
+
+	/* wait for transmit idle */
+	if( (filp->f_flags&(O_NDELAY|O_NONBLOCK)) == 0 ) {
+		digi_transmit_idle( port, DIGI_CLOSE_TIMEOUT );
+	}
+
+	/* drop DTR and RTS */
+	digi_set_modem_signals( port, 0, 0 );
+
+	/* disable input flow control */
+	buf[0] = DIGI_CMD_SET_INPUT_FLOW_CONTROL;
+	buf[1] = priv->dp_port_num;
+	buf[2] = DIGI_DISABLE;
+	buf[3] = 0;
+
+	/* disable output flow control */
+	buf[4] = DIGI_CMD_SET_OUTPUT_FLOW_CONTROL;
+	buf[5] = priv->dp_port_num;
+	buf[6] = DIGI_DISABLE;
+	buf[7] = 0;
+
+	/* disable reading modem signals automatically */
+	buf[8] = DIGI_CMD_READ_INPUT_SIGNALS;
+	buf[9] = priv->dp_port_num;
+	buf[10] = DIGI_DISABLE;
+	buf[11] = 0;
+
+	/* disable receive */
+	buf[12] = DIGI_CMD_RECEIVE_ENABLE;
+	buf[13] = priv->dp_port_num;
+	buf[14] = DIGI_DISABLE;
+	buf[15] = 0;
+
+	/* flush fifos */
+	buf[16] = DIGI_CMD_IFLUSH_FIFO;
+	buf[17] = priv->dp_port_num;
+	buf[18] = DIGI_FLUSH_TX | DIGI_FLUSH_RX;
+	buf[19] = 0;
+
+	if( (ret=digi_write_oob_command( port, buf, 20, 0 )) != 0 )
+		dbg( "digi_close: write oob failed, ret=%d", ret );
+
+	/* wait for final commands on oob port to complete */
+	interruptible_sleep_on_timeout( &priv->dp_flush_wait,
+		DIGI_CLOSE_TIMEOUT );
+
+	/* shutdown any outstanding bulk writes */
+	usb_unlink_urb (port->write_urb);
+
+	tty->closing = 0;
+
+	spin_lock_irqsave( &priv->dp_port_lock, flags );
+	port->active = 0;
+	priv->dp_write_urb_in_use = 0;
+	priv->dp_in_close = 0;
+	--priv->dp_open_count;
+	MOD_DEC_USE_COUNT;
+	wake_up_interruptible( &priv->dp_close_wait );
+	spin_unlock_irqrestore( &priv->dp_port_lock, flags );
+
+dbg( "digi_close: done" );
+}
+
+
+/*
+*  Digi Startup Device
+*
+*  Starts reads on all ports.  Must be called AFTER startup, with
+*  urbs initialized.  Returns 0 if successful, non-zero error otherwise.
+*/
+
+static int digi_startup_device( struct usb_serial *serial )
+{
+
+	int i,ret = 0;
+	digi_serial_t *serial_priv = (digi_serial_t *)serial->private;
+	struct usb_serial_port *port;
+
+
+	/* be sure this happens exactly once */
+	spin_lock( &serial_priv->ds_serial_lock );
+	if( serial_priv->ds_device_started ) {
+		spin_unlock( &serial_priv->ds_serial_lock );
+		return( 0 );
+	}
+	serial_priv->ds_device_started = 1;
+	spin_unlock( &serial_priv->ds_serial_lock );
+
+	/* start reading from each bulk in endpoint for the device */
+	/* set USB_DISABLE_SPD flag for write bulk urbs */
+	for( i=0; i<serial->type->num_ports+1; i++ ) {
+
+		port = &serial->port[i];
+
+		port->write_urb->dev = port->serial->dev;
+
+		if( (ret=usb_submit_urb(port->read_urb)) != 0 ) {
+			err(
+			__FUNCTION__ ": usb_submit_urb failed, ret=%d, port=%d",
+			ret, i );
+			break;
+		}
+
+	}
+
+	return( ret );
+
+}
+
+
+static int digi_startup( struct usb_serial *serial )
+{
+
+	int i;
+	digi_port_t *priv;
+	digi_serial_t *serial_priv;
+
+
+dbg( "digi_startup: TOP" );
+
+	/* allocate the private data structures for all ports */
+	/* number of regular ports + 1 for the out-of-band port */
+	for( i=0; i<serial->type->num_ports+1; i++ ) {
+
+		serial->port[i].active = 0;
+
+		/* allocate port private structure */
+		priv = serial->port[i].private =
+			(digi_port_t *)kmalloc( sizeof(digi_port_t),
+			GFP_KERNEL );
+		if( priv == (digi_port_t *)0 ) {
+			while( --i >= 0 )
+				kfree( serial->port[i].private );
+			return( 1 );			/* error */
+		}
+
+		/* initialize port private structure */
+		spin_lock_init( &priv->dp_port_lock );
+		priv->dp_port_num = i;
+		priv->dp_out_buf_len = 0;
+		priv->dp_in_buf_len = 0;
+		priv->dp_write_urb_in_use = 0;
+		priv->dp_modem_signals = 0;
+		init_waitqueue_head( &priv->dp_modem_change_wait );
+		priv->dp_open_count = 0;
+		priv->dp_transmit_idle = 0;
+		init_waitqueue_head( &priv->dp_transmit_idle_wait );
+		priv->dp_throttled = 0;
+		priv->dp_throttle_restart = 0;
+		init_waitqueue_head( &priv->dp_flush_wait );
+		priv->dp_in_close = 0;
+		init_waitqueue_head( &priv->dp_close_wait );
+		priv->dp_wakeup_task.next = NULL;
+		priv->dp_wakeup_task.sync = 0;
+		priv->dp_wakeup_task.routine = (void *)digi_wakeup_write_lock;
+		priv->dp_wakeup_task.data = (void *)(&serial->port[i]);
+
+		/* initialize write wait queue for this port */
+		init_waitqueue_head( &serial->port[i].write_wait );
+
+	}
+
+	/* allocate serial private structure */
+	serial_priv = serial->private =
+		(digi_serial_t *)kmalloc( sizeof(digi_serial_t),
+		GFP_KERNEL );
+	if( serial_priv == (digi_serial_t *)0 ) {
+		for( i=0; i<serial->type->num_ports+1; i++ )
+			kfree( serial->port[i].private );
+		return( 1 );			/* error */
+	}
+
+	/* initialize serial private structure */
+	spin_lock_init( &serial_priv->ds_serial_lock );
+	serial_priv->ds_oob_port_num = serial->type->num_ports;
+	serial_priv->ds_oob_port = &serial->port[serial_priv->ds_oob_port_num];
+	serial_priv->ds_device_started = 0;
+
+	return( 0 );
+
+}
+
+
+static void digi_shutdown( struct usb_serial *serial )
+{
+
+	int i;
+	digi_port_t *priv;
+	unsigned long flags;
+
+
+dbg( "digi_shutdown: TOP, in_interrupt()=%d", in_interrupt() );
+
+	/* stop reads and writes on all ports */
+	for( i=0; i<serial->type->num_ports+1; i++ ) {
+		usb_unlink_urb( serial->port[i].read_urb );
+		usb_unlink_urb( serial->port[i].write_urb );
+	}
+
+	/* dec module use count */
+	for( i=0; i<serial->type->num_ports; i++ ) {
+		priv = serial->port[i].private;
+		spin_lock_irqsave( &priv->dp_port_lock, flags );
+		while( priv->dp_open_count > 0 ) {
+			MOD_DEC_USE_COUNT;
+			--priv->dp_open_count;
+		}
+		spin_unlock_irqrestore( &priv->dp_port_lock, flags );
+	}
+
+	/* free the private data structures for all ports */
+	/* number of regular ports + 1 for the out-of-band port */
+	for( i=0; i<serial->type->num_ports+1; i++ )
+		kfree( serial->port[i].private );
+	kfree( serial->private );
+
+}
+
+
+static void digi_read_bulk_callback( struct urb *urb )
+{
+
+	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
+	digi_port_t *priv;
+	int ret;
+
+
+dbg( "digi_read_bulk_callback: TOP" );
+
+	/* port sanity check, do not resubmit if port is not valid */
+	if( port == NULL || (priv=(digi_port_t *)(port->private)) == NULL ) {
+		err( __FUNCTION__ ": port or port->private is NULL, status=%d",
+			urb->status );
+		return;
+	}
+	if( port->serial == NULL
+	|| serial_paranoia_check( port->serial, __FUNCTION__ )
+	|| port->serial->private == NULL ) {
+		err( __FUNCTION__ ": serial is bad or serial->private is NULL, status=%d", urb->status );
+		return;
+	}
+
+	/* do not resubmit urb if it has any status error */
+	if( urb->status ) {
+		err( __FUNCTION__ ": nonzero read bulk status: status=%d, port=%d", urb->status, priv->dp_port_num );
+		return;
+	}
+
+	/* handle oob or inb callback, do not resubmit if error */
+	if( priv->dp_port_num
+	== ((digi_serial_t *)(port->serial->private))->ds_oob_port_num ) {
+		if( digi_read_oob_callback( urb ) != 0 )
+			return;
+	} else {
+		if( digi_read_inb_callback( urb ) != 0 )
+			return;
+	}
+
+	/* continue read */
+	urb->dev = port->serial->dev;
+	if( (ret=usb_submit_urb(urb)) != 0 ) {
+		err( __FUNCTION__ ": failed resubmitting urb, ret=%d, port=%d",
+			ret, priv->dp_port_num );
+	}
+
+}
+
+
+/* 
+*  Digi Read INB Callback
+*
+*  Digi Read INB Callback handles reads on the in band ports, sending
+*  the data on to the tty subsystem.  When called we know port and
+*  port->private are not NULL and port->serial has been validated.
+*  It returns 0 if successful, 1 if successful but the port is
+*  throttled, and -1 if the sanity checks failed.
+*/
+
+static int digi_read_inb_callback( struct urb *urb )
+{
+
+	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
+	struct tty_struct *tty = port->tty;
+	digi_port_t *priv = (digi_port_t *)(port->private);
+	int opcode = ((unsigned char *)urb->transfer_buffer)[0];
+	int len = ((unsigned char *)urb->transfer_buffer)[1];
+	int status = ((unsigned char *)urb->transfer_buffer)[2];
+	unsigned char *data = ((unsigned char *)urb->transfer_buffer)+3;
+	int flag,throttled;
+
+
+	/* sanity check */
+	if( port_paranoia_check( port, __FUNCTION__ ) )
+		return( -1 );
+
+	/* do not process callbacks on closed ports */
+	/* but do continue the read chain */
+	if( priv->dp_open_count == 0 )
+		return( 0 );
+
+	/* short/multiple packet check */
+	if( urb->actual_length != len + 2 ) {
+     		err( __FUNCTION__ ": INCOMPLETE OR MULTIPLE PACKET, urb->status=%d, port=%d, opcode=%d, len=%d, actual_length=%d, status=%d", urb->status, priv->dp_port_num, opcode, len, urb->actual_length, status );
+		return( -1 );
+	}
+
+	spin_lock( &priv->dp_port_lock );
+
+	/* check for throttle; if set, do not resubmit read urb */
+	/* indicate the read chain needs to be restarted on unthrottle */
+	throttled = priv->dp_throttled;
+	if( throttled )
+		priv->dp_throttle_restart = 1;
+
+	/* receive data */
+	if( opcode == DIGI_CMD_RECEIVE_DATA ) {
+
+		/* get flag from status */
+		flag = 0;
+
+		/* overrun is special, not associated with a char */
+		if( status & DIGI_OVERRUN_ERROR ) {
+			tty_insert_flip_char( tty, 0, TTY_OVERRUN );
+		}
+
+		/* break takes precedence over parity, */
+		/* which takes precedence over framing errors */
+		if( status & DIGI_BREAK_ERROR ) {
+			flag = TTY_BREAK;
+		} else if( status & DIGI_PARITY_ERROR ) {
+			flag = TTY_PARITY;
+		} else if( status & DIGI_FRAMING_ERROR ) {
+			flag = TTY_FRAME;
+		}
+
+		/* data length is len-1 (one byte of len is status) */
+		--len;
+
+		if( throttled ) {
+
+			len = MIN( len,
+				DIGI_IN_BUF_SIZE - priv->dp_in_buf_len );
+
+			if( len > 0 ) {
+				memcpy( priv->dp_in_buf + priv->dp_in_buf_len,
+					data, len );
+				memset( priv->dp_in_flag_buf
+					+ priv->dp_in_buf_len, flag, len );
+				priv->dp_in_buf_len += len;
+			}
+
+		} else {
+
+			len = MIN( len, TTY_FLIPBUF_SIZE - tty->flip.count );
+
+			if( len > 0 ) {
+				memcpy( tty->flip.char_buf_ptr, data, len );
+				memset( tty->flip.flag_buf_ptr, flag, len );
+				tty->flip.char_buf_ptr += len;
+				tty->flip.flag_buf_ptr += len;
+				tty->flip.count += len;
+				tty_flip_buffer_push( tty );
+			}
+
+		}
+
+	}
+
+	spin_unlock( &priv->dp_port_lock );
+
+	if( opcode == DIGI_CMD_RECEIVE_DISABLE ) {
+		dbg( __FUNCTION__ ": got RECEIVE_DISABLE" );
+	} else if( opcode != DIGI_CMD_RECEIVE_DATA ) {
+		dbg( __FUNCTION__ ": unknown opcode: %d", opcode );
+	}
+
+	return( throttled ? 1 : 0 );
+
+}
+
+
+/* 
+*  Digi Read OOB Callback
+*
+*  Digi Read OOB Callback handles reads on the out of band port.
+*  When called we know port and port->private are not NULL and
+*  the port->serial is valid.  It returns 0 if successful, and
+*  -1 if the sanity checks failed.
+*/
+
+static int digi_read_oob_callback( struct urb *urb )
+{
+
+	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
+	struct usb_serial *serial = port->serial;
+	digi_port_t *priv = (digi_port_t *)(port->private);
+	int opcode, line, status, val;
+	int i;
+
+
+dbg( "digi_read_oob_callback: port=%d, len=%d", priv->dp_port_num,
+urb->actual_length );
+
+	/* handle each oob command */
+	for( i=0; i<urb->actual_length-3; ) {
+
+		opcode = ((unsigned char *)urb->transfer_buffer)[i++];
+		line = ((unsigned char *)urb->transfer_buffer)[i++];
+		status = ((unsigned char *)urb->transfer_buffer)[i++];
+		val = ((unsigned char *)urb->transfer_buffer)[i++];
+
+dbg( "digi_read_oob_callback: opcode=%d, line=%d, status=%d, val=%d",
+opcode, line, status, val );
+
+		if( status != 0 || line >= serial->type->num_ports )
+			continue;
+
+		port = &serial->port[line];
+
+		if( port_paranoia_check( port, __FUNCTION__ )
+		|| (priv=port->private) == NULL )
+			return( -1 );
+
+		if( opcode == DIGI_CMD_READ_INPUT_SIGNALS ) {
+
+			spin_lock( &priv->dp_port_lock );
+
+			/* convert from digi flags to termiox flags */
+			if( val & DIGI_READ_INPUT_SIGNALS_CTS ) {
+				priv->dp_modem_signals |= TIOCM_CTS;
+				/* port must be open to use tty struct */
+				if( priv->dp_open_count
+				&& port->tty->termios->c_cflag & CRTSCTS ) {
+					port->tty->hw_stopped = 0;
+					digi_wakeup_write( port );
+				}
+			} else {
+				priv->dp_modem_signals &= ~TIOCM_CTS;
+				/* port must be open to use tty struct */
+				if( priv->dp_open_count
+				&& port->tty->termios->c_cflag & CRTSCTS ) {
+					port->tty->hw_stopped = 1;
+				}
+			}
+			if( val & DIGI_READ_INPUT_SIGNALS_DSR )
+				priv->dp_modem_signals |= TIOCM_DSR;
+			else
+				priv->dp_modem_signals &= ~TIOCM_DSR;
+			if( val & DIGI_READ_INPUT_SIGNALS_RI )
+				priv->dp_modem_signals |= TIOCM_RI;
+			else
+				priv->dp_modem_signals &= ~TIOCM_RI;
+			if( val & DIGI_READ_INPUT_SIGNALS_DCD )
+				priv->dp_modem_signals |= TIOCM_CD;
+			else
+				priv->dp_modem_signals &= ~TIOCM_CD;
+
+			wake_up_interruptible( &priv->dp_modem_change_wait );
+			spin_unlock( &priv->dp_port_lock );
+
+		} else if( opcode == DIGI_CMD_TRANSMIT_IDLE ) {
+
+			spin_lock( &priv->dp_port_lock );
+			priv->dp_transmit_idle = 1;
+			wake_up_interruptible( &priv->dp_transmit_idle_wait );
+			spin_unlock( &priv->dp_port_lock );
+
+		} else if( opcode == DIGI_CMD_IFLUSH_FIFO ) {
+
+			wake_up_interruptible( &priv->dp_flush_wait );
+
+		}
+
+	}
+
+	return( 0 );
+
+}
+
+
+static int __init digi_init (void)
+{
+	usb_serial_register (&digi_acceleport_2_device);
+	usb_serial_register (&digi_acceleport_4_device);
+	return 0;
+}
+
+
+static void __exit digi_exit (void)
+{
+	usb_serial_deregister (&digi_acceleport_2_device);
+	usb_serial_deregister (&digi_acceleport_4_device);
+}
+
+
+module_init(digi_init);
+module_exit(digi_exit);
+
+
+MODULE_AUTHOR("Peter Berger <pberger@brimson.com>, Al Borchers <borchers@steinerpoint.com>");
+MODULE_DESCRIPTION("Digi AccelePort USB-2/USB-4 Serial Converter driver");
+