Re: [PATCH 02/12] clk: samsung: exynos5420: add cpu clock configuration data and instantiate cpu clock

From: Ben Gamari
Date: Thu Dec 03 2015 - 05:31:07 EST


Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx> writes:

> On 03.12.2015 06:19, Ben Gamari wrote:
>> From: Thomas Abraham <thomas.ab@xxxxxxxxxxx>
>>
>> With the addition of the new Samsung specific cpu-clock type, the
>> arm clock can be represented as a cpu-clock type. Add the CPU clock
>> configuration data and instantiate the CPU clock type for Exynos5420.
>>
>> Changes by Bartlomiej:
>> - split Exynos5420 support from the original patches
>> - moved E5420_[EGL,KFC]_DIV0() macros to clk-exynos5420.c
>>
>> Changes by Ben Gamari:
>> - Rebased
>
> If only rebasing then you should retain the Lukasz's review tag. He
> doesn't have to review it again, right? :)

Yep, very true.

>> +static const struct exynos_cpuclk_cfg_data exynos5420_eglclk_d[] __initconst = {
>> + { 1800000, E5420_EGL_DIV0(3, 7, 7, 4), },
>> + { 1700000, E5420_EGL_DIV0(3, 7, 7, 3), },
>> + { 1600000, E5420_EGL_DIV0(3, 7, 7, 3), },
>> + { 1500000, E5420_EGL_DIV0(3, 7, 7, 3), },
>> + { 1400000, E5420_EGL_DIV0(3, 7, 7, 3), },
>> + { 1300000, E5420_EGL_DIV0(3, 7, 7, 2), },
>> + { 1200000, E5420_EGL_DIV0(3, 7, 7, 2), },
>> + { 1100000, E5420_EGL_DIV0(3, 7, 7, 2), },
>> + { 1000000, E5420_EGL_DIV0(3, 6, 6, 2), },
>> + { 900000, E5420_EGL_DIV0(3, 6, 6, 2), },
>> + { 800000, E5420_EGL_DIV0(3, 5, 5, 2), },
>> + { 700000, E5420_EGL_DIV0(3, 5, 5, 2), },
>> + { 600000, E5420_EGL_DIV0(3, 4, 4, 2), },
>> + { 500000, E5420_EGL_DIV0(3, 3, 3, 2), },
>> + { 400000, E5420_EGL_DIV0(3, 3, 3, 2), },
>> + { 300000, E5420_EGL_DIV0(3, 3, 3, 2), },
>> + { 200000, E5420_EGL_DIV0(3, 3, 3, 2), },
>> + { 0 },
>
> The vendor code (Galaxy S5 with Exynos5422) sets pclk_dbg divider to 7.
> In the same time APLL divider is only 1.
>
> For the ACLK divider (of KFC below) the vendor sets 3, not 2.
>
> The values also don't match the Exynos5420 from Note 3.
>
> The Exynos5800 apparently has values more similar to 5422.
>
> The question is: for which exact model this is? We can of course choose
> the safest values here but probably these would be with the highest
> dividers?
>
I'm afraid I can't comment here. Thomas, perhaps you could offer some
insight?

Cheers,

- Ben

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