[WIP] HDMI CEC - need support

darqoq · Published in 2015-11-14 18:23:00

Dima replied at 2015-11-14 09:35
Yup, exactly the same result here...
Also tried libcec 2 (cause 3 that you compiled is not supported ...

I didn't check libcec 3.0.1 with kodi on Android, but I suppose that it is working with it, because (in debian linux) kodi-bin (for example 15.2) depends on libcec3 (>= 2.1.4).
Anyway, I compied libcec 3.0.1 to use cec-client (libcec 2.0.1 from ordroid forum doesn't have cec-client).

Also I don't think that te problem is with driver, I thought that the problem is with handshaking
"to start sending CEC signals the device need to do a handshake to the TV and announce itself as CEC receiver."
(http://forum.odroid.com/viewtopic.php?f=112&t=11959), cec-client can do this, but the problem is how to do that.
If libcec (ot other cec software) do handshake with TV, then remote (of this TV)
will be working with it (probably only butons listed by evtest). Also to work with kodi we need libcec (not other software).

jernej · Published in 2016-2-10 07:14:09

I took a quick look at kernel driver (disassembly) and I can tell you that you probably won't achieve anything with libcec. Driver directly connects CEC with devinput infrastructure, so it should behave like a keyboard or something. This is similar to sunxi_ir_rx module. evtest in this case should work once everything is correctly set up. This also means that you don't need anything special for kodi.

Did any of you checked libcec source code? Part of this code is something called adapter and AFAIK this is interface to specific driver. Unfortunately nothing sunxi or devinput related.

I must say that I don't know much technical details about CEC yet, so I might be wrong on some things.

incubus370 · Published in 2016-2-10 14:15:26

Edited by incubus370 at 2016-2-10 14:22

First, you should check if cec pin from hdmi port connected to SOC. if no connection or it connected to GND (also it may be connected to VCC line through pull up resistor), you can not do anything on software side only. Solution - connect to gpio and emulate CEC protocol (AV.link)

jernej · Published in 2016-2-10 17:37:18

Guys, we are missing something obvious. script.bin gpio for CEC is set to PA14 which is general purpose pin, OPiPC CEC pin is connected to HDMI's CEC pin. Also driver for CEC seems to bitbang protocol and doesn't use HW CEC registers at all. So my recommendation would be that someone unsolders R104 and connect it to PA14 pin. I would but I don't have much time for this now.

tomkowski · Published in 2016-2-18 15:43:23

Should I completely remove the R104? And what should I connect and where? I can do this.

Sorry for my english :/

jernej · Published in 2016-2-19 01:17:16

Yes, R104 is just 0 ohm resistor. You should remove it and HDMI connecto side of it solder to PA14 pin.

tomkowski · Published in 2016-2-19 03:03:16

jernej replied at 2016-2-19 01:17
Yes, R104 is just 0 ohm resistor. You should remove it and HDMI connecto side of it solder to PA14 p ...

PA14 = UART3_RX on CPU ?

jernej · Published in 2016-2-19 03:42:09

Yes. Protocol is emulated with GPIO.

rfve · Published in 2016-2-19 15:51:27

Edited by rfve at 2016-2-19 23:41

zhao_steven

why it says there is cec support in all orange products. but it does not support .
Kodi , Openelec , OSMC ??

jernej · Published in 2016-2-20 00:16:22

rfve replied at 2016-2-19 08:51
why it says there is cec support in all orange products. but it does not support .
Kodi , Openelec ...

It's a matter of perspective.

HW supports it, but that's all, because there is no linux driver for it. I asked zhao_steven already if he can provide one, but there was no response.

One particular Android image, referenced in this thread, has HDMI-CEC support. However, it seems to be completely emulated via GPIO and only soldering a wire would help, but that is not confirmed. Even if manage to fix CEC on this particular Android image, driver is compiled into the kernel itself, so we can't reuse it.