IrDA

CONFIG_ISA
CONFIG_NSC_FIR

I had tried to get this to work, since I have a Nokia 6310i GSM, but didn't reach anything useful. There's a FIR controller in the laptop, which, according to Fujitsu-Siemens' phone support, is a ``HP 2300 3600'' controller. I'm not sure whether that's spelled right, but in any case, I couldn't find any reference to this on the 'net, or in the IrDA-HOWTO.

I finally gave up trying to get the IrDA controller to work. Fortunately, Michael Mráka mailto:michael.mraka@linux.cz was more persistent than me, and did in fact reach success. The key to the puzzle was that I didn't expect the nsc-ircc driver to require ISA to function correctly, but apparently it does³. Oh well.

It's not entirely straightforward, though. The procedure is as follows:

• Unless you modified any serial settings in your BIOS, the IrDA port is at /dev/ttyS1, IO port 0x2f8, IRQ 3. Check that⁴; if this assumption is wrong, both your serial port and IrDA interface will not work.
• You'll have to perform some black magic with the module arguments to make sure the ``plain'' serial driver will not run away with the resources the nsc-ircc driver needs. Doing that is slightly different on 2.4 vs 2.6 kernels; so, you'll have to choose now:
  • For 2.6, edit or create the file /etc/modprobe.d/local (on a Debian system; if you're unfortunate enough to use something else⁵, go for /etc/modprobe.conf). The file should contain the following information:

    alias irda0 nsc-ircc
    alias char-major-4 8250
    install nsc-ircc /sbin/modprobe 8250; /sbin/modprobe --ignore-install nsc-ircc
    remove nsc-ircc /sbin/modprobe -r --ignore-remove nsc-ircc; /sbin/modprobe -r 8250
    install 8250 /sbin/modprobe --ignore-install 8250; /bin/setserial /dev/ttyS1 uart none port 0x0
    

    After that, on Debian, run ``update-modules'' to update the master file (other distributions should work right away).
  • For 2.4, edit or create the file /etc/modutils/local (on a Debian system; if you're using something else, go for /etc/modules.conf). The file should contain the following information:

    alias irda0 nsc-ircc
    alias char-major-4 serial
    pre-install nsc-ircc /sbin/modprobe serial
    post-remove nsc-ircc /sbin/modprobe -r serial
    post-install serial /bin/setserial /dev/ttyS1 uart none port 0x0
    

• That was the hardest part. Next, you'll need to install the ``irda-common'' package<sup>6</sup>.
• Once all that is done, you're all set. If you want to use the IrDA stack, you can start it using ``irattach irda0 -s''. Another option would be to have this starting at every boot (most distributions support this), but I recommend against doing so; loading the IrDA stack and running IrDA discovery all the time will deplete your battery rather fast. It's probably better to have it disabled until you're actually going to use it...

After doing all of the above, I could see my mobile phone in the discovery log, and I got ping-replies with ``irdaping'', so I guess it works. That doesn't mean I actually understand the ins and outs of the IrDA subsystem now, but at least I can be reasonably sure the hardware works now :-)