linux-kernel - Re: [resend PATCH v4 4/5] drm/mediatek: Add support for mmsys through a pdev

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Date:   Fri, 12 Oct 2018 11:23:14 -0700
From:   Stephen Boyd <sboyd@...nel.org>
To:     Laurent Pinchart <laurent.pinchart@...asonboard.com>,
        Sean Wang <sean.wang@...iatek.com>
Cc:     mark.rutland@....com, airlied@...ux.ie, mturquette@...libre.com,
        dri-devel@...ts.freedesktop.org, ulrich.hecht+renesas@...il.com,
        lee.jones@...aro.org, linux-clk@...r.kernel.org,
        linux@...linux.org.uk, ck.hu@...iatek.com, robh+dt@...nel.org,
        linux-mediatek@...ts.infradead.org, matthias.bgg@...il.com,
        mchehab@...nel.org, linux-arm-kernel@...ts.infradead.org,
        Matthias Brugger <mbrugger@...e.com>,
        gregkh@...uxfoundation.org, rdunlap@...radead.org,
        sboyd@...eaurora.org, linux-kernel@...r.kernel.org,
        p.zabel@...gutronix.de, matthias.bgg@...nel.org,
        pi-cheng.chen@...aro.org, davem@...emloft.net
Subject: Re: [resend PATCH v4 4/5] drm/mediatek: Add support for mmsys through a pdev

Quoting Stephen Boyd (2018-07-26 00:35:14)
> Quoting Sean Wang (2018-07-18 03:06:27)
> > On Wed, 2018-07-18 at 11:05 +0300, Laurent Pinchart wrote:
> > > Hi Sean,
> > > 
> > > This looks very strange to me. I'm not familiar with the hardware 
> > > architecture, but a clock controller that includes an audio controller seems 
> > > like a very weird design. It's usually the other way around, you have an audio
> > 
> > yes, naming audsys as clock controller is really not good. it should be
> > worth a better naming.
> > 
> > mtk subsystem AFAIK works as a container, at least provides clocks,
> > reset, syscon access, these common resource to these devices running on
> > the subsystem. It also has a power gate independent from other
> > subsystem, that can be controlled when these devices all powered down
> > or once up.
> > 
> > And it should be better that we don't assume what exact devices are
> > running on since it is possible that there're different devices running
> > on the same subsystem per SoC. mtk has many subsystem working in this
> > way. mmsys is just a case. we can see in [1]
> > 
> > 
> > [1]
> > https://elixir.bootlin.com/linux/v4.18-rc5/source/Documentation/devicetree/bindings/arm/mediatek
> >  
> 
> Sean, is this an ack for this patch series? I think the consensus is to
> not modify DT to add a subnode for the "clk" part of the hardware, but
> instead either register the clks from the device driver that has the clk
> hardware inside of it, or do what this patch series does and register a
> device in software from the "parent" device driver so that logically clk
> things are contained in drivers/clk/
> 

Please resend this series. This is too old now and I'm dropping this
from (the very tail) of my queue.