Linux Unwired [Electronic resources] نسخه متنی

8.2 PC Laptop with Built-In IrDA

There is a lot of hardware out there, and
it's all put together slightly differently. We got
infrared working under a couple of different distributions, both with
a dongle and the internal infrared. Your configuration should be
similar, but if you run into any trouble, check out Jean
Tourrilhes's Linux-IrDA Quick Tutorial at
http://www.hpl.hp.com/personal/Jean_Tourrilhes/IrDA/IrDAl.

To make sure you are up to date with the most recent bug and security fixes, make sure you've installed the most recent updates that are available for your Linux distribution, especially for the kernel and associated modules.

Out of the box, we were unable to get infrared working in SIR or FIR
mode on our computer, a ThinkPad A20m. On a whim, we went into the
BIOS and tried different IRQ and port settings. The combination of
IRQ 4 and port 0x3E8 did the trick. The ThinkPad
didn't let us switch from FIR to SIR mode in the
BIOS, but it let us use SIR mode without any complaints under several
Linux distributions.

On all of the Linux distributions described in the following list, we
performed some initial steps to discover the infrared port. First, we
booted the system, and then inspected the output of
dmesg to get a list of serial ports:

debian:~# dmesg | grep tty
ttyS01 at 0x02f8 (irq = 3) is a 16550A
ttyS02 at 0x03e8 (irq = 4) is a 16550A

We used this information to figure out which serial devices
corresponded to the infrared hardware. If there are a lot of serial
devices on your system, this may involve some guesswork or at least a
look around the BIOS settings. In this infrared port, we knew that
the first serial devices listed (/dev/ttyS1)
corresponds to the 9-pin serial port on the back of the computer, so
that left /dev/ttyS2.

In each of the following examples, we rebooted after making the
changes to ensure that everything worked. If you'd
like to preserve your uptime, try running
/etc/init.d/irda restart after
making the changes instead of rebooting.

Debian 3.0r1

Because the latest 2.4 kernel-image package (2.4.18-14.1) was showing
its age, we compiled and installed the latest kernel from source
(2.4.24). Other than that, we worked with a stock 3.0r1 install with
the latest updates. To get infrared working, we installed the
irda-common and irda-tools packages, and edited
/etc/irda.conf, setting
IRDADEV=/dev/ttyS2.
irda-common sets up
/etc/init.d/irda to start in all runlevels, so
we didn't need to modify any startup scripts.
However, Debian did not put our mortal user into the correct group
(dialout) to access serial ports, so we fixed that
with usermod -G dialout
username.

SuSE 9.0

The irda package, which was installed by
default, provided all the utilities we needed for IrDA support. We
set IRDA_PORT="/dev/ttyS2" in
/etc/sysconfig/irda. Next, we ran
insserv /etc/init.d/irda to enable IrDA support to
start at boot time.

Mandrake 9.2

To get infrared working, we installed the
irda-utils package and edited
/etc/sysconfig/irda, setting
DEVICE=/dev/ttyS2. irda-utils
sets up /etc/init.d/irda to start in all
runlevels, so we didn't need to modify any startup
scripts. Mandrake did not put our mortal user into the correct group
(uucp) to access serial ports, so we fixed that
with usermod -G uucp
username.

RedHat 9

The irda-utils package, which was installed by
default, provided all the utilities we needed for IrDA support. We
set DEVICE=/dev/ttyS2 in
/etc/sysconfig/irda. Next, we ran
chkconfig --level 5 irda on to enable IrDA support
to start in runlevel 5, the default runlevel for Red Hat Linux
running in graphical mode (check your
/etc/inittab to see the default runlevel for
your system or use the runlevel command to see your current
runlevel). Red Hat did not put our mortal user into the correct group
(uucp) to access serial ports, so we fixed that
with usermod -G uucp
username.

Gentoo 1.4

We installed the infrared utilities with emerge
irda-utils and set IRDADEV=/dev/ttyS2 in
/etc/conf.d/irda. Next, we enabled the
irda startup script with rc-update add
irda default. The ircomm devices were
owned by root, so we gave the uucp group access to them with
chgrp uucp /dev/ircomm* and
chmod g+rw /dev/ircomm*, and then gave our mortal
user access with usermod -G uucp
username.