From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Boyd Subject: Re: [PATCH v10 01/15] clk: tegra20/30: Add custom EMC clock implementation Date: Tue, 10 Sep 2019 03:33:04 -0700 Message-ID: <20190910103305.B4E1B20872@mail.kernel.org> References: <20190811210043.20122-1-digetx@gmail.com> <20190811210043.20122-2-digetx@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20190811210043.20122-2-digetx@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Dmitry Osipenko , Jonathan Hunter , Joseph Lo , Michael Turquette , Peter De Schrijver , Prashant Gaikwad , Rob Herring , Thierry Reding Cc: devicetree@vger.kernel.org, linux-clk@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-tegra@vger.kernel.org Quoting Dmitry Osipenko (2019-08-11 14:00:29) > A proper External Memory Controller clock rounding and parent selection > functionality is required by the EMC drivers, it is not available using > the generic clock implementation because only the Memory Controller driver > is aware of what clock rates are actually available for a particular > device. EMC drivers will have to register a Tegra-specific CLK-API > callback which will perform rounding of a requested rate. EMC clock users > won't be able to request EMC clock by getting -EPROBE_DEFER until EMC > driver is probed and the callback is set up. >=20 > The functionality is somewhat similar to the clk-emc.c which serves > Tegra124+ SoCs. The later HW generations support more parent clock sources > and the HW configuration / integration with the EMC drivers differs a tad > from the older gens, hence it's not really worth to try to squash > everything into a single source file. >=20 > Acked-by: Peter De Schrijver > Signed-off-by: Dmitry Osipenko > --- Acked-by: Stephen Boyd