The Linux Digiboard Driver
--------------------------

The Digiboard Driver for Linux supports the following boards:

 DigiBoard PC/Xi, PC/Xe, PC/Xeve(which is the newer, smaller Xe with
 a 8K window which is also known as PC/Xe(8K) and has no memory/irq
 switches) You can use up to 4 cards with this driver and it should work
 on other architectures than intel also.

A version of this driver has been taken by Digiboard to make a driver
software package which supports also PC/Xem cards and newer PCI cards
but it doesn't support the old PC/Xi cards and it isn't yet ported to
linux-2.1.x and may not be usable on other architectures than intel now.
It is available from ftp.digi.com/ftp.digiboard.com. You can write me if
you need an patch for this driver.

Bernhard Kaindl (bkaindl@netway.at)  6. April 1997.

Configuring the Driver
----------------------

The driver can be built direct into the kernel or as a module.
The pcxx driver can be configured using the command line feature while
loading the kernel with LILO or LOADLIN or, if built as a module,
with arguments to insmod and modprobe or with parameters in
/etc/modprobe.conf for modprobe and kerneld.

After configuring the driver you need to create the device special files
as described in "Device file creation:" below and set the appropriate
permissions for your application.

As Module
---------

modprobe pcxx io=<io> \
  membase=<membase> \
  memsize=<memsize> \
  numports=<numports>  \
  altpin=<altpin> \
  verbose=<verbose>

or, if several cards are installed

modprobe pcxx io=<io-1>,<io-2>,... \
  membase=<membase-1>,<membase-2>,... \
  memsize=<memsize-1>,<memsize-2>,... \
  numports=<numports-1>,<numports-2>,... \
  altpin=<altpin-1>,<altpin-2>,... \
  verbose=<verbose>

where <io-N> is the io address of the Nth card and <membase-N> is the
memory base address of the Nth card, etc.

The parameters can be specified in any order. For example, the numports
parameter can precede the membase parameter, or vice versa. If several
cards are installed the ordering within the comma separated parameter
lists must be consistent, of course.

io       - I/O port address of that card.
membase  - Memory start address of that card.
memsize  - Memory size of that card, in kilobytes. If given, this value
           is compared against the card to verify configuration and
           hinder the driver from using a misconfigured card. If the parameter
           does not match the board it is disabled with a memory size error.
numports - Number of ports on this card. This is the number of devices to
           assign to this card or reserve if disabled.
altpin   - 1: swap DCD and DSR for 8-pin RJ-45 with modems.
	   0: don't swap DCD and DSR.
           other values count as 1.
verbose  - 1: give nice verbose output during initialisation of the driver,
              possibly helpful during board configuration.
           0: normal terse output.

Only the parameters which differ from the defaults need to be specified.
If the io= parameter is not given, the default config is used. This is

  io=0x200 membase=0xD0000 numports=16 altpin=0

Only applicable parameters need be specified. For example to configure
2 boards, first one at 0x200 with 8 ports, rest defaults, second one at
0x120, memory at 0xD80000, altpin enabled, rest defaults, you can do this
by using these parameters:

  modprobe pcxx io=0x200,0x120 numports=8,8 membase=,0xD80000 altpin=,1

To disable a temporary unusable board without changing the mapping of the
devices following that board, you can empty the io-value for that board:

  modprobe pcxx io=,0x120 numports=8,8 membase=,0xD80000 altpin=,1

The remaining board still uses ttyD8-ttyD15 and cud8-cud15.

Example line for /etc/modprobe.conf for use with kerneld and as default
parameters for modprobe:

options pcxx           io=0x200 numports=8

For kmod to work you will likely need to add these two lines to your
/etc/modprobe.conf:

alias char-major-22    pcxx
alias char-major-23    pcxx


Boot-time configuration when linked into the kernel
---------------------------------------------------

Per board to be configured, pass a digi= command-line parameter to the
kernel using lilo or loadlin. It consists of a string of comma separated
identifiers or integers.  The 6 values in order are:

Card status:      Enable      - use that board
		  Disable     - don't actually use that board.

Card type:        PC/Xi       - the old ones with 64/128/256/512K RAM.
		  PC/Xe       - PC/Xe(old ones with 64k mem range).
		  PC/Xeve     - PC/Xe(new ones with 8k mem range).

Note: This is for documentation only, the type is detected from the board.

Altpin setting:   Enable      - swap DCD and DSR for 8-pin RJ-45 with modems.
		  Disable     - don't swap DCD and DSR.

Number of ports:  1 ... 16    - Number of ports on this card. This is the
				number of devices to assign to this card.

I/O port address: eg. 200     - I/O Port address where the card is configured.

Memory base addr: eg. 80000   - Memory address where the board's memory starts.

This is an example for a line which you can insert into you lilo.conf:

   append="digi=Enable,PC/Xi,Disable,4,120,D0000"

there is an alternate form, in which you must use decimal values only:

   append="digi=1,0,0,16,512,851968"

If you don't give a digi= command line, the compiled-in defaults of
board 1: io=0x200, membase=0xd0000, altpin=off and numports=16 are used.

If you have the resources (io&mem) free for use, configure your board to
these settings and you should be set up fine even if yours has not got 16 
ports.


Sources of Information
----------------------

Please contact digi directly digilnux@dgii.com. Forward any information of
general interest to me so that I can include it on the webpage.

Web page: http://lameter.com/digi

Christoph Lameter (christoph@lameter.com) Aug 14, 2000.

Device file creation
--------------------

Currently the Linux MAKEDEV command does not support generating the Digiboard
Devices. 

The /dev/cud devices behave like the /dev/cua devices
and the ttyD devices are like the /dev/ttyS devices.

Use the following script to generate the devices:

------------------ mkdigidev begin
#!/bin/sh
#
# Script to create Digiboard Devices
# Christoph Lameter, April 16, 1996
#
# Usage:
# mkdigidev [<number of devices>]
# 

DIGI_MAJOR=23
DIGICU_MAJOR=22

BOARDS=$1

if [ "$BOARDS" = "" ]; then
BOARDS=1
fi

boardnum=0
while [ $boardnum -lt $BOARDS ];
do
  for c in 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15;
  do
	name=`expr $boardnum \* 16 + $c`
	mknod /dev/cud$name c $DIGICU_MAJOR $name
	mknod /dev/ttyD$name c $DIGI_MAJOR $name
  done
  boardnum=`expr $boardnum + 1`
done
------------------ mkdigidev end

or apply the following patch to /dev/MAKEDEV and do a 
sh /dev/MAKEDEV digi

----- MAKEDEV Patch
--- /dev/MAKEDEV	Sun Aug 13 15:48:23 1995
+++ MAKEDEV	Tue Apr 16 17:53:27 1996
@@ -120,7 +120,7 @@
 	while [ $# -ne 0 ]
 	do
 		case "$1" in
-			mem|tty|ttyp|cua|cub)	;;
+			mem|tty|ttyp|cua|cub|cud)	;;
 			hd)	echo hda hdb hdc hdd ;;
 			xd)	echo xda xdb ;;
 			fd)	echo fd0 fd1 ;;
@@ -140,6 +140,7 @@
 			dcf)		echo dcf ;;
 			pcmcia)	;; # taken care of by its own driver
 			ttyC)	echo cyclades ;;
+			ttyD)	echo digi ;;
 			*)	echo "$0: don't know what \"$1\" is" >&2 ;;
 		esac
 		shift
@@ -208,6 +209,15 @@
 		do
 			makedev ttyC$i c $major1 `expr 32 + $i` $tty
 			makedev cub$i c $major2 `expr 32 + $i` $dialout
+		done
+		;;
+	digi)
+		major1=`Major ttyD` || continue
+		major2=`Major cud` || continue
+		for i in 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
+		do
+			makedev ttyD$i c $major1 `expr 32 + $i` $tty
+			makedev cud$i c $major2 `expr 32 + $i` $dialout
 		done
 		;;
 	par[0-2])
----- End Makedev patch

-----------------------------------------------------------------------------

Changes v1.5.5:

The ability to use the kernel's command line to pass in the configuration for 
boards.  Using LILO's APPEND command, a string of comma separated identifiers 
or integers can be used.  The 6 values in order are:

   Enable/Disable this card,
   Type of card: PC/Xi(0), PC/Xe(1), PC/Xeve(2), PC/Xem(3)
   Enable/Disable alternate pin arrangement,
   Number of ports on this card,
   I/O Port where card is configured (in HEX if using string identifiers),
   Base of memory window (in HEX if using string identifiers), 

Samples:
   append="digi=E,PC/Xi,D,16,200,D0000"
   append="digi=1,0,0,16,512,(whatever D0000 is in base 10 :)

Drivers' minor device numbers are conserved. This means that instead of
each board getting a block of 16 minors pre-assigned, it gets however
many it should, with the next card following directly behind it.  A
system with 4 2-port PC/Xi boards will use minor numbers 0-7.
This conserves some memory, and removes a few hard coded constants.

NOTE!! NOTE!! NOTE!!
The definition of PC/Xem as a valid board type is the BEGINNING of support
for this device.  The driver does not currently recognise the board, nor
does it want to initialize it.  At least not the EISA version.

Mike McLagan <mike.mclagan@linux.org> 5, April 1996.
