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References: <20220124121009.108649-1-alistair@alistair23.me> <20220124121009.108649-3-alistair@alistair23.me>
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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Tue, 8 Mar 2022 11:53:39 +0100
Message-ID: <CAMuHMdVNgVQzjrdybbnfCEr+G5Q4ztjRCC29RF9HwGnhKkPn3Q@mail.gmail.com>
Subject: Re: [PATCH v18 2/8] mfd: simple-mfd-i2c: Add a Kconfig name
To:     Alistair Francis <alistair@alistair23.me>
Cc:     Mark Brown <broonie@kernel.org>, Rob Herring <robh+dt@kernel.org>,
        Sascha Hauer <kernel@pengutronix.de>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Lee Jones <lee.jones@linaro.org>,
        Linux PM list <linux-pm@vger.kernel.org>,
        linux-hwmon@vger.kernel.org,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>, NXP Linux Team <linux-imx@nxp.com>,
        Zhang Rui <rui.zhang@intel.com>, alistair23@gmail.com,
        Amit Kucheria <amitk@kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Andreas Kemnade <andreas@kemnade.info>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Shawn Guo <shawnguo@kernel.org>
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Hi Alistair,

Thanks for your patch, which is now commit bae5a4acef67db88
("mfd: simple-mfd-i2c: Add a Kconfig name") in mfd/for-mfd-next.

On Mon, Jan 24, 2022 at 1:24 PM Alistair Francis <alistair@alistair23.me> wrote:
> Add a Kconfig name to the "Simple Multi-Functional Device support (I2C)"
> device so that it can be enabled via menuconfig.

Which still does not explain why this would be needed...

> Signed-off-by: Alistair Francis <alistair@alistair23.me>
> Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org>

> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -1188,7 +1188,7 @@ config MFD_SI476X_CORE
>           module will be called si476x-core.
>
>  config MFD_SIMPLE_MFD_I2C
> -       tristate
> +       tristate "Simple Multi-Functional Device support (I2C)"
>         depends on I2C
>         select MFD_CORE
>         select REGMAP_I2C

The help text states:

| This driver creates a single register map with the intention for it
| to be shared by all sub-devices.

Yes, that's what MFD does?

| Once the register map has been successfully initialised, any
| sub-devices represented by child nodes in Device Tree will be
| subsequently registered.

OK...?

Still, no clue about what this driver really does, and why and when
it would be needed.

There is one driver symbol that selects MFD_SIMPLE_MFD_I2C.
There are no driver symbols that depend on this symbol.

If you have a driver in the pipeline that can make use of this,
can't it just select MFD_SIMPLE_MFD_I2C, so the symbol itself can
stay invisible?

Thanks!

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds