Re: [PATCH v2 2/2] clk: meson: g12a: add cpu clocks
From: Neil Armstrong
Date: Thu Mar 07 2019 - 07:24:51 EST
Hi Martin,
On 05/03/2019 22:10, Martin Blumenstingl wrote:
> On Mon, Mar 4, 2019 at 2:12 PM Neil Armstrong <narmstrong@xxxxxxxxxxxx> wrote:
>>
>> Add the Amlogic G12A Family CPU Clock tree in read/only for now.
>>
>> The CPU clock can either use the SYS_PLL for > 1GHz frequencies or
>> use a couple of div+mux from 1GHz/667MHz/24MHz source with 2 non-glitch
>> muxes.
>>
>> Proper DVFS support will come in a second time.
>>
>> Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
>
> in my previous review I criticized that the post-dividers are not
> mentioned in the description.
> it's not part of v2 but after having a closer look again I think it's
> not a big issue:
> these CPU post-dividers are all marked as read-only and have a comment
> that "ROM monitor code" manages them.
Sorry indeed I forgot to say a word about this, but you pointed the right
thing, they are only here to be complete, not to be used (for now).
Neil
>
> disclaimer for my "reviewed-by":
> - I don't have access to the datasheet so I can't verify if the clock
> tree from this patch is correct
> - the latest buildroot code with G12A support
> (buildroot_openlinux_kernel_4.9_fbdev_20180706) doesn't have proper
> names for all clocks
> - this review is based on my experience with Meson8* (where Linux also
> manages the CPU clock, unlike on the GX SoCs where it's managed in
> firmware)
>
>
> Regards
> Martin
>