Am 18.08.19 um 09:19 schrieb Chuanhong Guo:

Hi!

On Sun, Aug 18, 2019 at 2:10 PM Oleksij Rempel [off-list ref] wrote:

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We have at least 2 know registers:
SYSC_REG_CPLL_CLKCFG0 - it provides some information about boostrapped
refclock. PLL and dividers used for CPU and some sort of BUS (AHB?).
SYSC_REG_CPLL_CLKCFG1 - a banch of gates to enable/disable clocks for
all or some ip cores.
What is probably missing is a set of dividers for
each ip core. From your words it is not document.

The specific missing part I was referring to, is parent clocks for
every gates. I'm not going to assume this with current openwrt device
tree because some peripherals doesn't have a clock binding at all or
have a dummy one there.

Ok, then I do not understand what is the motivation to upstream
something what is not nearly ready for use.

Why isn't it "ready for use" then?
A complete mt7621-pll driver will contain two parts:
1. A clock provider which outputs several clocks
2. A clock gate with parent clocks properly configured

Two clocks provided here are just two clocks that can't be controlled
in kernel no matter where it goes (arch/mips/ralink or drivers/clk).
Having a working CPU clock provider is better than defining a fixed
clock in dts because CPU clock can be controlled by bootloader.
(BTW description for CPU PLL register is also missing in datasheet.)
Clock gate is an unrelated part and there is no information to
properly implement it unless MTK decided to release a clock plan
somehow.

With other words, your complete system is running with unknown clock
rates. The source clock in the clock three can be configured differently
by bootloader but you don't know how it is done how and it is not
documented.

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This code is currently on prototyping phase

Code for clock calculation is done, not "prototyping".

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It means, we cannot expect that this driver will be fixed any time soon.

I think clock gating is a separated feature instead of a broken part
that has to be fixed.

Ok, i would agree with it. But from what you said, this feature will be
never implemented.

So, I repeat my question. What is the point to upstream code for a
system, which has not enough information to get proper clock rate even
for uart? or is uart running with cpu or bus clock rate?

--
Regards,
Oleksij