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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Thu, 16 Apr 2020 13:06:57 +0200
Message-ID: <CAK8P3a26JS4FVt5wiaRQahF+OJZp9Ot84o8GSth9Rk2skkEMSQ@mail.gmail.com>
Subject: Re: [RFC 00/11] Add generic MFD i.MX mix and audiomix support
To:     Abel Vesa <abel.vesa@nxp.com>
Cc:     Rob Herring <robh@kernel.org>, Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <kernel@pengutronix.de>,
        Fabio Estevam <fabio.estevam@nxp.com>,
        Mike Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Lee Jones <lee.jones@linaro.org>,
        Anson Huang <anson.huang@nxp.com>,
        Leonard Crestez <leonard.crestez@nxp.com>,
        Peng Fan <peng.fan@nxp.com>, Jacky Bai <ping.bai@nxp.com>,
        NXP Linux Team <linux-imx@nxp.com>,
        DTML <devicetree@vger.kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-clk <linux-clk@vger.kernel.org>
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On Thu, Apr 16, 2020 at 1:06 PM Arnd Bergmann <arnd@arndb.de> wrote:
>
> On Tue, Mar 3, 2020 at 10:04 AM Abel Vesa <abel.vesa@nxp.com> wrote:
> >
> > The i.MX8MP has some new IPs called mixes. They are formed usually by some
> > GPRs that can be split into different functionalities. The first example
> > here is the audiomix which has dedicated registers that can be registered
> > as a clock controller and some other registers that can be registered as
> > a reset controller, plus some dedicated ones that will be registered as
> > syscon and used by each dedicated audio IP.
> >
> > More mixes to be following the same structure are to come, like hdmimix,
> > dispmix and mediamix. They will all be populated and registered by the MFD
> > imx-mix generic driver.
>
> Can you enumerate what functionality is in each one?
>
> I'm not convinced that using an MFD driver is the best solution here,
> compared to e.g. a clk driver with a few extra bits in it, if most of the
> code for the child drivers ends up being for the clk subsystem.
>
> Lee suggested maybe having a generic (platform independent) driver
> for it, which may help here, as it would let others share the trivial
> mfd portion.
>
> Another option that we are using on several platforms today is to
> have a single syscon node and have other drivers that reference
> that one using a phandle to get at the regmap.

Sorry I replied to the wrong thread, I meant to reply to the v3 version.

       Arnd