[PATCHv2 0/3] dw-hdmi: add property to disable CEC

[Martin Blumenstingl]

Hi Neil,

On Sat, Mar 24, 2018 at 2:41 PM, Neil Armstrong <narmstrong at baylibre.com> wrote:
> Hi Martin,
>
>> Le 24 mars 2018 à 12:00, Martin Blumenstingl <martin.blumenstingl at googlemail.com> a écrit :
>>
>> Hello Hans, Hi Neil,
>>
>> (apologies in advance if any of this is wrong, I don't have any CEC
>> capable TV so I can't test it)
>>
>> On Fri, Mar 23, 2018 at 1:59 PM, Hans Verkuil <hverkuil at xs4all.nl> wrote:
>>> From: Hans Verkuil <hans.verkuil at cisco.com>
>>>
>>> Some boards (amlogic) have two CEC controllers: the DesignWare controller
>>> and their own CEC controller (meson ao-cec).
>> as far as I understand the Amlogic Meson SoCs have two domains:
>> - AO (always-on, powered even in suspend mode) where meson-ao-cec can
>> wake up the system from suspend
>> - EE (everything else, not powered during suspend) where dw-hdmi-cec lives
>>
>
> Exact, except … the EE CEC is not hooked to the DW-HDMI TX but the RX, and thus cannot be used on GXBB/GXL/GXM.
I see, thank you for the explanation

>> this far everything is OK
>>
>>> Since the CEC line is not hooked up to the DW controller we need a way
>>> to disable that controller. This patch series adds the cec-disable
>>> property for that purpose.
>> drivers/pinctrl/meson/pinctrl-meson-gxbb.c has ao_cec_pins and
>> ee_cec_pins, both use GPIOAO_12
>> drivers/pinctrl/meson/pinctrl-meson-gxl.c has ao_cec_pins and
>> ee_cec_pins, both use GPIOAO_8
>>
>> @Neil: do you know if the CEC signal routing is:
>> ao_cec_pins -> meson-ao-cec
>> ee_cec_pins -> dw-hdmi-cec
>
> It’s hooked to the DW-HDMI RX IP used in the TV SoCs.
>
>>
>> I'm curious because if both CEC controllers can be used then it might
>> be worth mentioning this in the cover-letter and patch description
>>
>
> Initially I thought it was hooked to the DW-HDMI TX, but no, I guess I should remove the ee_cec pinmux…
right, or rename it to ee_cec_rx (or something similar)


Regards
Martin