Hi!

On Sun, Aug 18, 2019 at 2:06 AM Oleksij Rempel [off-list ref] wrote:

quoted

quoted

SYSC_REG_CPLL_CLKCFG1 register is a clock gate controller. It is used to enable or disable clocks.
Jist wild assumption. All peripheral devices are suing bus clock.

This assumption is incorrect. When this patchset is applied in
OpenWrt, I asked the author why there's still a fixed clock in
mt7621.dtsi, He told me that there's another clock for those unchanged
peripherals and he doesn't have time to write a clock provider for it.

Can you please provide a link to this patch or email.

This discussion is in Chinese and using an IM software so there's no
link available.

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.

With this information the clk driver will provide gate functionality and
a set of hardcoded clocks. With this driver will work part of power
management and nice devicetree without fixed clocks.

Regards,
Chuanhong Guo