Re: [PATCH v6 1/3] dt-bindings: display: bridge: Document THC63LVD1024 LVDS decoder

From: Vladimir Zapolskiy
Date: Tue Mar 27 2018 - 04:30:46 EST


Hi Sergei,

On 03/27/2018 11:27 AM, Sergei Shtylyov wrote:
> Hello!
>
> On 3/27/2018 10:33 AM, jacopo mondi wrote:
> [...]
>>>>>>> Document Thine THC63LVD1024 LVDS decoder device tree bindings.
>>>>>>>
>>>>>>> Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
>>>>>>> Reviewed-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
>>>>>>> Reviewed-by: Niklas SÃderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
>>>>>>> ---
>>>>>>> .../bindings/display/bridge/thine,thc63lvd1024.txt | 66 +++++++++++++++++++
>>>>>>> 1 file changed, 66 insertions(+)
>>>>>>> create mode 100644
>>>>>>> Documentation/devicetree/bindings/display/bridge/thine,thc63lvd1024.txt
>>>>>>>
>>>>>>> diff --git
>>>>>>> a/Documentation/devicetree/bindings/display/bridge/thine,thc63lvd1024.txt
>>>>>>> b/Documentation/devicetree/bindings/display/bridge/thine,thc63lvd1024.txt
>>>>>>> new file mode 100644
>>>>>>> index 0000000..8225c6a
>>>>>>> --- /dev/null
>>>>>>> +++
>>>>>>> b/Documentation/devicetree/bindings/display/bridge/thine,thc63lvd1024.txt
>>>>>>> @@ -0,0 +1,66 @@
>>>>>>> +Thine Electronics THC63LVD1024 LVDS decoder
>>>>>>> +-------------------------------------------
>>>>>>> +
>>>>>>> +The THC63LVD1024 is a dual link LVDS receiver designed to convert LVDS
>>>>>>> streams
>>>>>>> +to parallel data outputs. The chip supports single/dual input/output modes,
>>>>>>> +handling up to two two input LVDS stream and up to two digital CMOS/TTL
>>>>>>> outputs.
>>>>>>> +
>>>>>>> +Single or dual operation modes, output data mapping and DDR output modes
>>>>>>> are
>>>>>>> +configured through input signals and the chip does not expose any control
>>>>>>> bus.
>>>>>>> +
>>>>>>> +Required properties:
>>>>>>> +- compatible: Shall be "thine,thc63lvd1024"
>>>>>>> +
>>>>>>> +Optional properties:
>>>>>>> +- vcc-supply: Power supply for TTL output and digital circuitry
>>>>>>> +- cvcc-supply: Power supply for TTL CLOCKOUT signal
>>>>>>> +- lvcc-supply: Power supply for LVDS inputs
>>>>>>> +- pvcc-supply: Power supply for PLL circuitry
>>>>>> As explained in a comment to one of the previous versions of this series, I'm
>>>>>> tempted to make vcc-supply mandatory and drop the three other power supplies
>>>>>> for now, as I believe there's very little chance they will be connected to
>>>>>> separately controllable regulators (all supplies use the same voltage). In the
>>>>>> very unlikely event that this occurs in design we need to support in the
>>>>>> future, the cvcc, lvcc and pvcc supplies can be added later as optional
>>>>>> without breaking backward compatibility.
>>>>> I'm okay with that.
>>>>>
>>>>>> Apart from that,
>>>>>>
>>>>>> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
>>>>>>
>>>>>>> +- pdwn-gpios: Power down GPIO signal. Active low
>>>>> powerdown-gpios is the semi-standard name.
>>>>>
>>>> right, I've also noticed it. If possible please avoid shortenings in
>>>> property names.
>>>
>>> It is not shortening, it just follow pin name from decoder's datasheet.
>>>
>>>>
>>>>>>> +- oe-gpios: Output enable GPIO signal. Active high
>>>>>>> +
>>>> And this one is also a not ever met property name, please consider to
>>>> rename it to 'enable-gpios', for instance display panels define it.
>>>
>>>
>>> Again, it follows datasheet naming scheme. Has something changed in DT
>>> conventions?
>>
>> Seconded. My understanding is that the property name should reflect
>> what reported in the the chip manual. For THC63LVD1024 the enable and
>> power down pins are named 'OE' and 'PDWN' respectively.
>
> But don't we need the vendor prefix in the prop names then, like
> "renesas,oe-gpios" then?
>

Seconded, with a correction to "thine,oe-gpios".

If vendor agnostic properties are supposed to be used, then please follow
the referenced by Rob semi-standard notations.

--
With best wishes,
Vladimir