Re: [PATCH 1/2] soc: samsung: exynos-pmu: instantiate clkout driver as MFD

From: Sylwester Nawrocki
Date: Fri Oct 23 2020 - 07:34:26 EST


Hi,

On 10/1/20 18:56, Krzysztof Kozlowski wrote:
> The Exynos clock output (clkout) driver uses same register address space
> (Power Management Unit address space) as Exynos PMU driver and same set
> of compatibles. It was modeled as clock provider instantiated with
> CLK_OF_DECLARE_DRIVE().
>
> This however brings ordering problems and lack of probe deferral,
> therefore clkout driver should be converted to a regular module and
> instantiated as a child of PMU driver to be able to use existing
> compatibles and address space.

It might have been cleaner to have the CLKOUT device as a PMU subnode in DT,
then device instantiation would be already covered by devm_of_platform_populate().
But it gets a bit complicated to make such a change in a backward compatible way.

I have tested both patches on Trats2, where CLKOUT provides master clock for
the audio codec.

Reviewed-by: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
Tested-by: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>


> @@ -128,6 +134,11 @@ static int exynos_pmu_probe(struct platform_device *pdev)
>
> platform_set_drvdata(pdev, pmu_context);
>
> + ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE, exynos_pmu_devs,
> + ARRAY_SIZE(exynos_pmu_devs), NULL, 0, NULL);
> + if (ret)
> + return ret;
> +
> if (devm_of_platform_populate(dev))
> dev_err(dev, "Error populating children, reboot and poweroff might not work properly\n");