Re: [PATCH v4 01/10] clk: tegra20/30: Add custom EMC clock implementation

Stephen Boyd
2019-06-19T01:14:25Z

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 able
> > 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.
> >
> > Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> > ---
> > 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
>
> Hi Mike, Stephen,
>
> 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.
>

Sure. I have review comments though so hopefully they can be addressed
first.