6/9/2000-

This is a device driver for the EDF Link Receiver Board (PC-MIP card).
This is very preliminary and seems to work, but "Caveat Downloader"!
Contact <hazen@bu.edu> with any comments/questions.

Files in this archive:

  2522 2000-05-31 11:52 lrb.h			Header file
  9505 2000-06-06 13:17 lrb.c			driver source code
   665 2000-06-06 13:17 Makefile		yes
  1686 2000-06-09 09:37 driver_demo.c		demo program

Requirements:

  Linux 2.2 or later kernel on Intel
    (only tested with stock RedHat 6.0 kernel v2.2.5-15)

  Some PCI device with no more than one BAR (base address register)
  which must be in memory.  Currently set up for LRB.


What works:

  Access to configuration space and one BAR0 address of 4 bytes.
  Only one card is currently supported.

  Configuration space can be accessed by setting the file pointer
  (using lseek()) to a value 0-255.  Byte, word and dword accesses are
  supported (only).

  The BAR0 address is accessed by setting the file pointer to 256.

  There is also untested code to access configuration space using
  ioctls, which works as follows:

     ioctl( fd, addr | LRB_IOC_WRITE | LRB_IOC_BYTE, (long)&data);
     
  This will write one byte to config address "addr".
  (see lrb.h for LRB_IOC_xxxx symbols);


To Do:

   Support access to BAR0 area bigger than 4 bytes!
   Requires changing:
     lrb_bar0 = ioremap_nocache( bar0, 4);

   Support for more than one card of a type.

   Make ioctl() the primary way of accessing configuration space,
   get rid of the current kludge of using addresses 0-255 for config.



Installation:

  cd <some_working_directory>
  tar -xzvf <archive_file>

  Make lrb.o		# compile, can be done as normal user

  Make devices		# do ONCE as root to make files in /dev

  Make install		# to copy lrb.o (driver) to system modules directory
			# (this is not necessary)

  insmod ./lrb.o	# as root to install device driver... needed
			# once after reboot

  make driver_demo	# compile
  ./driver_demo         # and run demo program


Debugging:

  1.  "more /proc/pci" for a list of PCI devices.
      Try to find your card by it's Vendor and Device ID.
      Here is the entry for the LRB on our system:

     Bus  1, device   4, function  0:
       RAM memory: Unknown vendor Unknown device (rev 1).
	 Vendor id=55. Device id=1.
	 Fast devsel.  
	 Non-prefetchable 32 bit memory at 0xdd000000 [0xdd000000].

  2.  Check that the device file is correct (after doing "make devices")

      # ls -l /dev/lrb*
      crw-rw-rw-   1 root     root     242,   0 Jun  4 06:20 /dev/lrb0


  3.  "/sbin/lsmod" to be sure the device driver is installed.  (after
      doing "insmod ./lrb.o" as root) Here is the beginning of the list
      on our system with lrb.o installed:

     Module                  Size  Used by
     lrb                     1476   0  (unused)


  4.  "cat /proc/devices" to check for the installed driver:

	Character devices:
	  1 mem
	  2 pty
	  3 ttyp
	  4 ttyS
	  5 cua
	  7 vcs
	 10 misc
	 29 fb
	 36 netlink
	128 ptm
	136 pts
	242 lrb	<----------- here is the lrb

      Note that I have somewhat arbitrarily chosen major# 242 for the
      lrb.  If there is some other device claiming this number
      (check the list before installing lrb.o) then you will have to
      change LRB_MAJOR in lrb.h and re-make everything.


  5.  Compile and run the demo program:

        make driver_demo
	./driver_demo

      If you get:

	# ./driver_demo 
	VENDOR ID = 0x0055
	DEVICE ID = 0x0001
	Read rc=4  data= 0x00000000
	Error Reading 2 bytes from PCI: Input/output error
	Read rc=-1  data= 0x00000000

      Then everything is working!

      If you get:

        Error Opening PCI device: No such file or directory

      Then the device driver isn't there... try the above steps.

      You can also uncomment the line:
           # DEBUG=-DLRB_DEBUG
      In the Makefile and re-compile the driver.

      This will put lots of debugging output into the syslog stream
      (you can normally access this in real time by typing
        "tail -f /var/log/messages"
      as root)