Tango4 clkgen block

Måns Rullgård mans at mansr.com
Fri Nov 20 04:08:39 PST 2015


Marc Gonzalez <marc_gonzalez at sigmadesigns.com> writes:

> Måns Rullgård wrote:
>
>> Marc Gonzalez wrote:
>> 
>>> For example, what is the point of not ignoring sysclk_premux, when the boot
>>> loader has always hard-coded "PLL1 drives sys_clk, PLL2 drives cd_clk".
>> 
>> What if the boot loader changes?  Since we know the structure of the
>> clock tree, it's safer to check how it is actually configured.
>
> In my opinion, this might be the problem.
>
> You think you grok the clkgen block, based on
>
> 1) buggy driver code written by Sigma
> 2) obsolete and/or incorrect documentation (it mentions tango1 for crying out loud)
> 3) limited testing on 8642 and 8759

I also have documentation for SMP8654 that I found on some Chinese web
site.  I've played around with most of the controls, and things behave
as expected.  Where the Sigma code and documentation are ambiguous or
disagree, I have tested what the hardware actually does for various
values.

-- 
Måns Rullgård
mans at mansr.com



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