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Date: Sat, 30 Mar 2024 20:34:35 +0000
From: friederhannenheim@riseup.net
To: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Marge Yang <marge.yang@tw.synaptics.com>, linux-input@vger.kernel.org,
 linux-kernel@vger.kernel.org
Subject: Re: [PATCH] input/touchscreen: synaptics_tcm_oncell: add driver
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References: <20240327214643.7055-1-friederhannenheim@riseup.net>
 <ZgWuq1bDWNRtrImD@google.com>
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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://github.com/LineageOS/android_kernel_oneplus_sm8250 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