Message-ID: <01ce15ee-ad64-6d0d-3b72-9d11eac8d40e@marcan.st>
Date:   Tue, 28 Feb 2023 11:43:31 +0900
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Subject: Re: [PATCH RFC 0/4] Driver for Apple Z2 touchscreens.
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To:     fnkl.kernel@gmail.com, Sven Peter <sven@svenpeter.dev>,
        Alyssa Rosenzweig <alyssa@rosenzweig.io>,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        - <asahi@lists.linux.dev>, Henrik Rydberg <rydberg@bitmath.org>
Cc:     linux-arm-kernel@lists.infradead.org, linux-input@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20230223-z2-for-ml-v1-0-028f2b85dc15@gmail.com>
From:   Hector Martin <marcan@marcan.st>
In-Reply-To: <20230223-z2-for-ml-v1-0-028f2b85dc15@gmail.com>
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On 24/02/2023 19.20, Sasha Finkelstein via B4 Relay wrote:
> Hi.
> 
> This series adds support for Apple touchscreens using the Z2 protocol.
> Those are used as the primary touchscreen on mobile Apple devices, and for the
> touchbar on laptops using the M-series chips. (T1/T2 laptops have a coprocessor
> in charge of speaking Z2 to the touchbar).
> 
> Sending this as a RFC for now, since this series requires the SPI controller
> support which is not upstream yet:
> https://lore.kernel.org/all/20211212034726.26306-1-marcan@marcan.st/
> 
> Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>

Just FWIW, I'm happy to see this get RFCed early (early review is always
good), but I don't think we should submit it until it actually gets some
testing in real-world scenarios. That is naturally blocked on having a
MIPI display driver, since a touchscreen above a dead screen isn't
terribly useful. Otherwise, we might realize that we have some
binding/API issues we missed that are harder to fix after the fact.

So let's hold off on submission proper until we have the screen working
and some basic userspace tooling to go with all this shipping downstream
and it gets some real-world testing. Hopefully by then I'll have sent
out the SPI controller driver too :)

- Hector