Re: [PATCH 4/5] clk: mediatek: Add subsystem clocks of MT8173

From: James Liao <jamesjj.liao@mediatek.com>
To: Daniel Kurtz <djkurtz@chromium.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>,
	Mike Turquette <mturquette@linaro.org>,
	Stephen Boyd <sboyd@codeaurora.org>,
	srv_heupstream <srv_heupstream@mediatek.com>,
	Ricky Liang <jcliang@chromium.org>,
	Rob Herring <robh+dt@kernel.org>,
	Sascha Hauer <kernel@pengutronix.de>,
	"open list:OPEN FIRMWARE AND..." <devicetree@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	<linux-mediatek@lists.infradead.org>
Subject: Re: [PATCH 4/5] clk: mediatek: Add subsystem clocks of MT8173
Date: Fri, 22 May 2015 14:03:10 +0800	[thread overview]
Message-ID: <1432274590.14396.40.camel@mtksdaap41> (raw)
In-Reply-To: <CAGS+omBgbj=Hx57GhxsQiuTR8Cx=hu0j4ptUh3GkScA81r42=A@mail.gmail.com>

Hi Daniel,

On Fri, 2015-05-22 at 12:22 +0800, Daniel Kurtz wrote:
> On Thu, May 21, 2015 at 3:12 PM, James Liao <jamesjj.liao@mediatek.com> wrote:
> > Most multimedia subsystem clocks will be accessed by multiple
> > drivers, so it's a better way to manage these clocks in CCF.
> > This patch adds clock support for MM, IMG, VDEC, VENC and VENC_LT
> > subsystems.
> 
> Is there a reason why this patch (or patch set) does not also include
> definitions for the SCP_SYS, AUDIO and MFG_SYS clocks?

Clocks of SCP_SYS is a workaround in our previous internal
implementation. It should be replaced with new mtk-scpsys driver which
implemented in pm_domain framework because they are used to power on/off
subsystem domains.

I had discussed with Sascha, and he said it not worth the overhead of
CCF for clocks that are not shared by different units. As I know AUDIO
and MFG clocks are only used by their own drivers. So I don't include
them in this patch.

Best regards,

James