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Date:   Fri, 24 Feb 2023 12:08:27 +0100
From:   "Sven Peter" <sven@svenpeter.dev>
To:     "Sasha Finkelstein" <fnkl.kernel@gmail.com>,
        "Mark Kettenis" <mark.kettenis@xs4all.nl>
Cc:     "Hector Martin" <marcan@marcan.st>,
        "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>,
        linux-arm-kernel@lists.infradead.org, linux-input@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH RFC 1/4] dt-bindings: input: touchscreen: Add Z2 controller
 bindings.
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Hi,


On Fri, Feb 24, 2023, at 12:04, Sasha Finkelstein wrote:
> On Fri, 24 Feb 2023 at 11:55, Mark Kettenis <mark.kettenis@xs4all.nl> wrote:
>
>> What is the motivation for including the firmware name in the device
>> tree rather than constructing it in the driver like what is done for
>> the broadcom wireless?
> There is no way to identify the device subtype before the firmware is
> uploaded, and so i need some way of figuring out which firmware to use.

Some Broadcom bluetooth boards use the compatible of the root node (see
btbcm_get_board_name in drivers/bluetooth/btbcm.c) which would be "apple,jXXX"
for Apple Silicon. I believe the Broadcom WiFi driver has similar logic as well
which marcan had to extend to instead of "brcm,board-type" because different
WiFi boards can me matched to different Apple Silicon boards. I don't think
that's the case for this touchscreen though.


Sven