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From:   Arnd Bergmann <arnd@kernel.org>
Date:   Tue, 28 Sep 2021 10:51:36 +0200
Message-ID: <CAK8P3a11c6eLRWKvQeSqvEicc9bMDeEEGV5fygTidoRzYf9KnQ@mail.gmail.com>
Subject: Re: [PATCH 1/2] firmware: include drivers/firmware/Kconfig unconditionally
To:     Charles Keepax <ckeepax@opensource.cirrus.com>
Cc:     Bjorn Andersson <bjorn.andersson@linaro.org>,
        Arnd Bergmann <arnd@arndb.de>, Mark Brown <broonie@kernel.org>,
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On Tue, Sep 28, 2021 at 10:37 AM Charles Keepax
<ckeepax@opensource.cirrus.com> wrote:
>
> Thanks for looking at this for us. I don't think we are greatly
> attached to drivers/firmware as a location. Essentially, what we
> have is some firmware parsing code that needs to be shared across
> several devices, previously this was just in the sound subsystem as
> all our parts were audio. We are going to shortly be upstreaming
> some non-audio parts that use the same firmware infrastructure
> and it didn't seem very sensible to have them including bits of
> the audio subsystem.
>
> I guess the question might be where else would said code go?
> drivers/firmware seemed most obvious, all the other locations
> I can think of don't really make sense. Can't really put it a bus
> like spi/i2c etc. because we have parts on many buses. Can't
> really put it in a functional subsystem (audio/input etc.) since
> the whole idea was to try and get some independence from that so
> we don't have parts including subsystems they don't use. Could
> maybe put it in MFD, but no hard guarantee every part using it
> will be an MFD device and I am fairly confident Lee will feel it
> isn't MFD code as it doesn't relate to managing multiple devices.
> Only other option I can think of would be to make some sort of
> drivers/dsp or maybe drivers/cs_dsp, but not clear to me that is
> obviously better than using drivers/firmware.

Other DSPs use the drivers/remoteproc/ subsystem, but that
is more for general-purpose DSPs that can load application
specific firmware rather than loading a single firmware blob
as you'd normally do with the request_firmware() style interface.

Not sure if that fits what you do. Can you point to a high-level
description of what this DSP does besides audio, and how
flexible it is? That might help find the right place for this.

       Arnd