[PATCH v2 0/2] meson8b: register the clock controller early

Jerome Brunet jbrunet at baylibre.com
Wed Sep 26 02:57:58 PDT 2018


On Sat, 2018-09-01 at 18:21 +0200, Martin Blumenstingl wrote:
> Some parts of the SoC are initialized early in the boot process, such
> as the SRAM and the TWD timer. This means that the corresponding
> drivers need to access the clock controller early as well.
> 
> Before this series the clock controller was registered as platform
> driver, which is too late for the TWD timer (just as an example).
> The reset controller (built into the clock controller driver) was
> already registered early, basically for the same reason (the reset
> lines are used to start the secondary CPUs, which is done very early
> in the boot process).
> 
> Register the clock controller early enough so we're able to use the
> TWD timer (as we need to pass a clock which is provided by this
> clock controller) in a second step.
> 
> NOTE: Neil suggested in v1 to switch to one of core_initcall,
> postcore_initcall, subsys_initcall but I couldn't find any driver
> that I could use as "reference" which registers it's clock controller
> before the device model (platform_device) is ready. this is why I'm
> still using CLK_OF_DECLARE - but I'm open to suggestions.
> 
> The second patch simplifies the reset controller (built into the clock
> controller driver) because the regmap is already available early and
> thus can be used by the reset controller driver as well.
> 
> 
> Changes since v1 at [0]:
> - switch from CLK_OF_DECLARE_DRIVER to CLK_OF_DECLARE because with
>   this series there is only one initialization function for the clock
>   controller driver (unlike before: where the reset controller was
>   registered early and the clock controller was registered as platform
>   device)
> - rebased on top of clk-meson, commit:
>   684b97b13b175a ("clk: meson-axg: pcie: drop the mpll3 clock parent")
> 
> 
> [0] https://patchwork.kernel.org/cover/10538971/

As explained earlier, the clock framework is trying to avoid CLK_OF_DECLARE*
In this case, I don't see a away around it yet so:

Rebased and Applied

but should keep trying to remove this is future, when possible.

Thx

> 
> 
> Martin Blumenstingl (2):
>   clk: meson: meson8b: register the clock controller early
>   clk: meson: meson8b: use the regmap in the internal reset controller
> 
>  drivers/clk/meson/meson8b.c | 110 +++++++++++++-----------------------
>  1 file changed, 40 insertions(+), 70 deletions(-)
> 





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