From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [RFC PATCH 3/3] clk: tegra: Implement Tegra124 shared/cbus clks Date: Tue, 13 May 2014 12:09:49 -0600 Message-ID: <53725FED.7050303@wwwdotorg.org> References: <1399990023-30318-1-git-send-email-pdeschrijver@nvidia.com> <1399990023-30318-4-git-send-email-pdeschrijver@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1399990023-30318-4-git-send-email-pdeschrijver-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Peter De Schrijver Cc: Mike Turquette , Prashant Gaikwad , Thierry Reding , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Arnd Bergmann , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On 05/13/2014 08:06 AM, Peter De Schrijver wrote: > Add shared and cbus clocks to the Tegra124 clock implementation. > diff --git a/include/dt-bindings/clock/tegra124-car.h b/include/dt-bindings/clock/tegra124-car.h > +#define TEGRA124_CLK_C2BUS 401 > +#define TEGRA124_CLK_C3BUS 402 > +#define TEGRA124_CLK_GR3D_CBUS 403 > +#define TEGRA124_CLK_GR2D_CBUS 404 ... I worry about this a bit. IIUC, these clocks don't actually exist in HW, but are more a way of SW applying policy to the clock that do exist in HW. As such, I'm not convinced it's a good idea to expose these clock IDS to DT, since DT is supposed to represent the HW, and not be influenced by internal SW implementation details. Do any DTs actually need to used these new clock IDs? I don't think we could actually use these value in e.g. tegra124.dtsi's clocks properties, since these clocks don't exist in HW. Was it your intent to do that? If not, can't we just define these SW-internal clock IDs in the header inside the Tegra clock driver, so the values are invisible to DT?