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Date:   Thu, 7 Dec 2023 09:34:59 +0000
From:   Conor Dooley <conor.dooley@microchip.com>
To:     Shengyang Chen <shengyang.chen@starfivetech.com>
CC:     Conor Dooley <conor@kernel.org>, <devicetree@vger.kernel.org>,
        <dri-devel@lists.freedesktop.org>, <neil.armstrong@linaro.org>,
        <quic_jesszhan@quicinc.com>, <sam@ravnborg.org>,
        <airlied@gmail.com>, <daniel@ffwll.ch>,
        <maarten.lankhorst@linux.intel.com>, <mripard@kernel.org>,
        <tzimmermann@suse.de>, <robh+dt@kernel.org>,
        <krzysztof.kozlowski+dt@linaro.org>, <conor+dt@kernel.org>,
        <florian.fainelli@broadcom.com>,
        <bcm-kernel-feedback-list@broadcom.com>, <eric@anholt.net>,
        <thierry.reding@gmail.com>, <changhuang.liang@starfivetech.com>,
        <keith.zhao@starfivetech.com>, <jack.zhu@starfivetech.com>,
        <linux-rpi-kernel@lists.infradead.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v1 1/2] dt-bindings: display: panel: raspberrypi: Add
 compatible property for waveshare 7inch touchscreen panel
Message-ID: <20231207-dullness-deprive-ece2d47ff69d@wendy>
References: <20231124104451.44271-1-shengyang.chen@starfivetech.com>
 <20231124104451.44271-2-shengyang.chen@starfivetech.com>
 <20231124-lesser-sinister-7f9cd7b80e35@spud>
 <2d48e460-e46e-431f-bd7b-e34ebe73a40c@starfivetech.com>
 <20231206-isolating-smoked-b490952029d0@spud>
 <53b992e8-1b36-4540-a993-fde8e550faf9@starfivetech.com>
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On Thu, Dec 07, 2023 at 11:48:56AM +0800, Shengyang Chen wrote:
> Hi, Conor
>=20
> thanks for comment
>=20
> On 2023/12/6 23:40, Conor Dooley wrote:
> > On Wed, Dec 06, 2023 at 05:43:48PM +0800, Shengyang Chen wrote:
> >> Hi, Conor
> >>=20
> >> On 2023/11/24 20:31, Conor Dooley wrote:
> >> > On Fri, Nov 24, 2023 at 06:44:50PM +0800, Shengyang Chen wrote:
> >> >> The waveshare 7inch touchscreen panel is a kind of raspberrypi pi
> >> >> panel
> >> >=20
> >> > Can you be more specific about what "is a kind of rpi panel" means?
> >> > Are they using identical chips as controllers or something like that?
> >> >=20
> >>=20
> >> Wareshare panel has same i2c slave address and registers address with=
=20
> >> the original raspberry pi panel. They both use Atmel firmware and they
> >> got same reg id. It can be operated by using the driver of raspberry p=
i driver
> >> after some change of the code. So I suppose it may be a kind of raspbe=
rry pi panel=20
> >> and discribe it in this way. It's my own judgement. Sorry about that.
> >> Maybe just like Dave said, It cloned the behaviour of the raspberri pi=
 panel.
> >> I will change the discribtion in next version to not make other confus=
ed.
> >>=20
> >> By the way, we will try Stefan's method before next version.=20
> >> The method we used in this patch may be abandoned if Stefan's method i=
s verified in our platform.
> >> At that time yaml may also be changed to fit new method.
> >=20
> > I don't know what Stefan's approach is, but I do not think that a
> > bindings patch should be dropped. The waveshare might be a clone, but it
> > is a distinct device. If the same driver can control both, then the
> > compatible setups that should be permitted are:
> > compatible =3D "raspberrypi,7inch-touchscreen-panel";
> > and
> > compatible =3D "waveshare,7inch-touchscreen-panel", "raspberrypi,7inch-=
touchscreen-panel";

> If we use Stenfan's method, we can reuse the code of panel-simple.c
> we may submit our patch to
> /Documentation/devicetree/bindings/display/panel/panel-simple.yaml
> /drivers/gpu/drm/panel/panel-simple.c
> as a new panel porting. That may less confuse.

As long as you provide a specific compatible, and not re-use the rpi
one, that's fine. It just sounded like you were intending to reuse that
here, but from this message it seems like I misunderstood.

Thanks,
Conor.

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