Re: [PATCH v10 01/15] clk: tegra20/30: Add custom EMC clock implementation
From: Stephen Boyd
Date: Tue Sep 10 2019 - 06:33:08 EST
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.
>
> 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.
>
> Acked-by: Peter De Schrijver <pdeschrijver@xxxxxxxxxx>
> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
> ---
Acked-by: Stephen Boyd <sboyd@xxxxxxxxxx>