RE: [PATCH] input/touchscreen: synaptics_tcm_oncell: add driver

[Marge Yang]

Loop Scott Lin

Scott Lin is responsible for mobile products.

Thanks
Marge Yang


-----Original Message-----
From: friederhannenheim@xxxxxxxxxx <friederhannenheim@xxxxxxxxxx> 
Sent: Sunday, March 31, 2024 4:35 AM
To: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
Cc: Marge Yang <Marge.Yang@xxxxxxxxxxxxxxxx>; linux-input@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
Subject: Re: [PATCH] input/touchscreen: synaptics_tcm_oncell: add driver

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On 2024-03-28 18:53, Dmitry Torokhov wrote:
> [ now CCing for real ]
>
> Hi Frieder,
>
> On Wed, Mar 27, 2024 at 10:39:12PM +0100, Frieder Hannenheim wrote:
>> This is a bit of a stripped down and partially reworked driver for 
>> the synaptics_tcm_oncell touchscreen. I based my work off the driver 
>> in the LineageOS kernel found at 
>> https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_Linea
>> geOS_android-5Fkernel-5Foneplus-5Fsm8250&d=DwICAg&c=7dfBJ8cXbWjhc0BhI
>> mu8wVIoUFmBzj1s88r8EGyM0UY&r=ddk_91asmhyAjxFmXHNIQZ2mVcW0D_eq4tb4409nZ94&m=2_iuhvyQkYcT-qsozPf_h9irH_AlUtaQ020UAxVQhZ3SuHgXYihgVocHyTV-zNSV&s=FT4Hkpxkhqktmhyz4RWC9lGAD4DvNBS06wQnn4ofQkk&e=  branch lineage-20. The code was originally written by OnePlus developers but I'm not sure how to credit them correctly.
>
> So the first question is: does this device not use Synaptics RMI4 
> protocol?
>
> I am CCing Marge Yang of Synaptics who may shed some light on the kind 
> of touch controller this is.
>
> Thanks.
Hi Dmitri,

the synaptics-s3908 uses a command based protocol whereas rmi4 is register-based (as far as I understand it, I haven't been able to read up on it properly since information on the internet is sparse). So I'm pretty sure that it can not be controlled via rmi4.

Best wishes,
Frieder