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Message-ID: <0a035c62-9d35-4f85-b1f3-bcb7dea17d52@gmail.com>
Date:   Mon, 4 Dec 2023 14:40:44 +0200
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Subject: Re: [PATCH v3 2/5] dt-bindings: input/touchscreen: Add compatible for
 IST3038B
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To:     Conor Dooley <conor@kernel.org>,
        Karel Balej <karelb@gimli.ms.mff.cuni.cz>
Cc:     Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Henrik Rydberg <rydberg@bitmath.org>,
        linux-input@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        =?UTF-8?Q?Duje_Mihanovi=C4=87?= <duje.mihanovic@skole.hr>,
        ~postmarketos/upstreaming@lists.sr.ht, phone-devel@vger.kernel.org,
        Karel Balej <balejk@matfyz.cz>
References: <20231202125948.10345-1-karelb@gimli.ms.mff.cuni.cz>
 <20231202125948.10345-3-karelb@gimli.ms.mff.cuni.cz>
 <20231203-outskirts-reformat-e0a833903841@spud>
From:   Markuss Broks <markuss.broks@gmail.com>
In-Reply-To: <20231203-outskirts-reformat-e0a833903841@spud>
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Hi Conor,

On 12/3/23 13:20, Conor Dooley wrote:
> On Sat, Dec 02, 2023 at 01:48:33PM +0100, Karel Balej wrote:
>> From: Markuss Broks <markuss.broks@gmail.com>
>>
>> Imagis IST3038B is a variant (firmware?) of Imagis IST3038 IC,
>> add the compatible for it to the IST3038C bindings.
> This one is better, but would be well served by mentioning what
> specifically is different (register addresses or firmware commands?)

I don't think anyone knows this other than Imagis itself. I would guess 
it's different hardware, since register addresses are indeed different, 
but on the other hand, there is a possibility that firmware on the MCU 
could be responding to those commands. I suppose "... IST3038B is a 
hardware variant of ... IST3038" would be more correct.

The reason why I think it could be firmware-defined is because we have a 
lot of variants (30xxA, 30xxB, 30xxC, plain 30xx), and the numbers 
usually mean feature level/completeness, e.g. some don't support the 
touch pressure or touchkeys, and we don't know what A/B/C/none means.

>
> Cheers,
> Conor.
>
>> Signed-off-by: Markuss Broks <markuss.broks@gmail.com>
>> Signed-off-by: Karel Balej <balejk@matfyz.cz>
>> ---
>>   .../devicetree/bindings/input/touchscreen/imagis,ist3038c.yaml   | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/Documentation/devicetree/bindings/input/touchscreen/imagis,ist3038c.yaml b/Documentation/devicetree/bindings/input/touchscreen/imagis,ist3038c.yaml
>> index 0d6b033fd5fb..b5372c4eae56 100644
>> --- a/Documentation/devicetree/bindings/input/touchscreen/imagis,ist3038c.yaml
>> +++ b/Documentation/devicetree/bindings/input/touchscreen/imagis,ist3038c.yaml
>> @@ -18,6 +18,7 @@ properties:
>>   
>>     compatible:
>>       enum:
>> +      - imagis,ist3038b
>>         - imagis,ist3038c
>>   
>>     reg:
>> -- 
>> 2.43.0
>>
- Markuss