LIRC on Raspberry Pi 4B

Hello,

I try to set up LIRC on a Raspberry Pi OS but doin't even have a
/dev/lirc0.

I downloaded the Raspberry Pi OS last week, the kernel version is
5.10.60-v7l+.

I located the IR related kernel modules in this directory:

/lib/modules/5.10.60-v7l+/kernel/drivers/media/rc
In there are gpio-ir-recv.ko and gpio-ir-tx.ko (which I don't need).
Also, there is no "gpio-ir.ko", but some more "ir-*.ko".

When I do "modprobe gpio-ir-recv" I see no fails in "journalctl -f".

But also when "ls -l /dev | grep lirc" shows no output at all.

"lsmod | grep gpio" shows:
gpio_ir_recv    16384 0

To my understanding, the gpio-ir-recv is sufficient to provide a
"/dev/lirc0", is that correct?
Also when I additionally do "modprobe ir-rc5-decoder" then there is no
/dev/lirc*.

I tried numerous Howtos I found, most refer to "gpio-ir", not "gpio-ir-
recv", I did not yet find out if this is the same.

Also, on the Raspi many Howtos describe changing /boot/config.txt to
mention the kernel module in there.  I tried that, it makes no
difference.

As a receiver I use the "RemotePi Board + 2015" which has the GPIO
compatible IR receiver on GPIO18

To my understanding this fail seems to be very basic and already in the
lowest layers (no userspace involved yet) and the points that could
influence it are:
- boot/config.txt
- the used kernel module
- the GPIO pin

To my understanding, the configuration in /etc/lirc is not yet
important, am I correct?

Has anybody got a hint on what to try to make LIRC work on the
Raspberry Pi 4B?


Thanks for any hints,
Torsten