libcec: update to libcec-next

[MilhouseVH]

Replacement for #4282. Will track the development branch until there is a new release.

[MilhouseVH]

PR380 has now merged upstream. but presumably we still only want to enable HAVE_LINUX_API for Allwinner/Amlogic/Rockchip (at this time)? With #4288 we'll be adding RPi to that list - what's the reason for continuing to disable it on Generic? @Kwiboo @HiassofT

[lrusak]

PR380 has now merged upstream. but presumably we still only want to enable HAVE_LINUX_API for Allwinner/Amlogic/Rockchip (at this time)? With #4288 we'll be adding RPi to that list - what's the reason for continuing to disable it on Generic? @Kwiboo @HiassofT

@MilhouseVH we don't enable the CEC media API on the Generic kernel. If you want to use the HAVE_LINUX_API then you'll need to enable the corresponding kernel config items.

[MilhouseVH]

If you want to use the HAVE_LINUX_API then you'll need to enable the corresponding kernel config items.

Is that something worth investigating? Any expected benefits (other than consistency)? I don't really have any CEC capable hardware so can't test anything myself. CEC is pretty much voodoo to me...!

[bdutro]

FWIW, it seems like CEC support is enabled by default in the Generic kernel. I plugged in a USB-C -> HDMI adapter with CEC passthrough and it creates a /dev/cec0 device. Then I made a side build of libcec and ran it on my LibreELEC box and got this output:

libCEC version: 4.0.4,  compiled on 2020-04-17 22:50:35 by root@3711c0b86ecf on Linux 5.6.4-arch1-1 (x86_64), features: P8_USB, DRM, P8_detect, randr, Linux
Found devices: 1

device:              1
com port:            Linux
vendor id:           0000
product id:          0000
firmware version:    0
type:                Linux

[bdutro]

I did a custom Generic build of LIbreelec with CEC_FRAMEWORK_SUPPORT="yes" and I can confirm that CEC is working well.

[useful64]

In addition, the use of version libCEC 5.0.0 could be reviewed.

On the libcec webpage it says that Kodi 18.x is not compatible, but I do not know if with Kodi 19.x.

[MilhouseVH]

No further updates for this PR.