From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Boyd Subject: Re: [PATCH v4 01/10] clk: tegra20/30: Add custom EMC clock implementation Date: Tue, 18 Jun 2019 18:14:25 -0700 Message-ID: <20190619011426.98D632085A@mail.kernel.org> References: <20190616233551.6838-1-digetx@gmail.com> <20190616233551.6838-2-digetx@gmail.com> <20190618122108.GO28892@ulmo> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20190618122108.GO28892@ulmo> Sender: linux-kernel-owner@vger.kernel.org To: Michael Turquette , Thierry Reding Cc: Dmitry Osipenko , Rob Herring , Joseph Lo , Jonathan Hunter , Peter De Schrijver , Prashant Gaikwad , devicetree@vger.kernel.org, linux-clk@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: devicetree@vger.kernel.org Quoting Thierry Reding (2019-06-18 05:21:08) > On Mon, Jun 17, 2019 at 02:35:42AM +0300, Dmitry Osipenko wrote: > > 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, hence add a custom one. The clock rate > > rounding shall be done by the EMC drivers because they have information > > about available memory timings, so the drivers will have to register a > > callback that will round the requested rate. EMC clock users won't be a= ble > > to request EMC clock by getting -EPROBE_DEFER until EMC driver is probed > > and the callback is set up. The functionality is somewhat similar to the > > clk-emc.c which serves Tegra124+ SoC's, the later HW generations support > > more parent clock sources and the HW configuration and 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 > > Signed-off-by: Dmitry Osipenko > > --- > > drivers/clk/tegra/Makefile | 2 + > > drivers/clk/tegra/clk-tegra20-emc.c | 305 ++++++++++++++++++++++++++++ > > drivers/clk/tegra/clk-tegra20.c | 55 ++--- > > drivers/clk/tegra/clk-tegra30.c | 38 +++- > > drivers/clk/tegra/clk.h | 6 + > > include/linux/clk/tegra.h | 14 ++ > > 6 files changed, 368 insertions(+), 52 deletions(-) > > create mode 100644 drivers/clk/tegra/clk-tegra20-emc.c >=20 > Hi Mike, Stephen, >=20 > The remaining patches of this series have a build-time dependency on > this clock driver patch. Would you mind if I pick this up into the Tegra > tree, so that I can resolve the dependency there? I can send a pull > request of the stable branch with this one patch if we need to resolve a > conflict between the clk and Tegra trees. >=20 Sure. I have review comments though so hopefully they can be addressed first.