Modern versions of Linux and MythTV enable infrared remote controls without the need for lirc. Here's how I migrated my Streamzap remote to evdev.

Installing packages

In order to avoid conflicts between evdev and lirc, I started by removing lirc and its config:

apt purge lirc

and then I installed this tool:

apt install ir-keytable

Remapping keys

While my Streamzap remote works out of the box with kernel 3.16, the keycodes that it sends to Xorg are not the ones that MythTV expects.

I therefore copied the existing mapping:

cp /lib/udev/rc_keymaps/streamzap /home/mythtv/

and changed it to this:

0x28c0 KEY_0
0x28c1 KEY_1
0x28c2 KEY_2
0x28c3 KEY_3
0x28c4 KEY_4
0x28c5 KEY_5
0x28c6 KEY_6
0x28c7 KEY_7
0x28c8 KEY_8
0x28c9 KEY_9
0x28ca KEY_ESC
0x28cb KEY_MUTE # |
0x28cc KEY_UP
0x28ce KEY_DOWN
0x28d0 KEY_UP
0x28d1 KEY_LEFT
0x28d2 KEY_ENTER
0x28d3 KEY_RIGHT
0x28d4 KEY_DOWN
0x28d5 KEY_M
0x28d6 KEY_ESC
0x28d7 KEY_L
0x28d8 KEY_P
0x28d9 KEY_ESC
0x28da KEY_BACK # <
0x28db KEY_FORWARD # >
0x28dc KEY_R
0x28e0 KEY_D
0x28e1 KEY_I
0x28e2 KEY_END
0x28e3 KEY_A

The complete list of all EV_KEY keycodes can be found in the kernel.

The following command will write this mapping to the driver:

/usr/bin/ir-keytable w /home/mythtv/streamzap -d /dev/input/by-id/usb-Streamzap__Inc._Streamzap_Remote_Control-event-if00

and they should take effect once MythTV is restarted.

Applying the mapping at boot

While the naïve solution is to apply the mapping at boot (for example, by sticking it in /etc/rc.local), that only works if the right modules are loaded before rc.local runs.

A much better solution is to write a udev rule so that the mapping is written after the driver is loaded.

I created /etc/udev/rules.d/streamzap.rules with the following:

# Configure remote control for MythTV
ACTION=="add", ATTRS{idVendor}=="0e9c", ATTRS{idProduct}=="0000", RUN+="/usr/bin/ir-keytable -c -w /home/mythtv/streamzap -D 1000 -P 250 -d /dev/input/by-id/usb-Streamzap__Inc._Streamzap_Remote_Control-event-if00"

and got the vendor and product IDs using:

grep '^[IN]:' /proc/bus/input/devices

The -D and -P parameters control what happens when a button on the remote is held down and the keypress must be repeated. These delays are in milliseconds.