Quoting Thierry Reding (2019-06-18 05:21:08)

On Mon, Jun 17, 2019 at 02:35:42AM +0300, Dmitry Osipenko wrote:

quoted

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.