Re: [PATCH 0/2] clk: thead: th1520-ap: allow gate cascade and fix padctrl0

[Drew Fustini]

On Thu, Aug 14, 2025 at 01:16:16AM +0800, Icenowy Zheng wrote:
> 在 2025-08-14星期四的 01:11 +0800，Icenowy Zheng写道：
> > Current ccu_gate implementation does not easily allow gates to be
> > clock
> > parents because of the waste of struct clk_hw in struct ccu_gate;
> > however it's found that the padctrl0 apb clock gate seems to be
> > downstream of perisys-apb4-hclk, gating the latter w/o gating the
> > former
> > makes the padctrl0 registers inaccessible too.
> > 
> > Fix this by refactor ccu_gate code, mimicing what Yao Zi did on
> > ccu_mux; and then assign perisys-apb4-hclk as parent of padctrl0 bus
> > gate.
> 
> Forgot to mention a easy test of this patchset:
> 
> Just install `gpioset` from `libgpiod` on a Lichee Pi 4A, plug a fan to
> its fan port, and run `gpioset 3 3=1`. The expected behavior is the fan
> starts to spin (because GPIO3_3 is the pin controlling the fan),
> however without this patchset Linux will fail to switch that pin.

Thanks. That worked great and the fan is spinning :)

Drew