Re: [PATCH v1 15/30] clk: starfive: Use regmap APIs to operate registers

Stephen Boyd
2022-10-27T01:26:16Z

Quoting Hal Feng (2022-10-22 21:11:41)
> On Wed, 12 Oct 2022 16:05:23 -0700, Stephen Boyd wrote:
> > I think we should use auxiliary bus and split the driver logically into
> > a reset driver in drivers/reset and a clk driver in drivers/clk. That
> > way the appropriate maintainers can review the code. There is only one
> > platform device with a single reg property and node in DT, but there are
> > two drivers.
>
> Yes, I agree that the reset driver and the clock driver should be split.
> However, I think using auxiliary bus is a little bit complicated in this
> case, because the reset is not a part of functionality of the clock in
> JH7110. They just share a common register base address.

That is why auxiliary bus exists.

> I think it is
> better to use ioremap for the same address, and the dt will be like
>
> syscrg_clk: clock-controller@13020000 {
> compatible = "starfive,jh7110-clkgen-sys";
> reg = <0x0 0x13020000 0x0 0x10000>;
> ...
> };
> syscrg_rst: reset-controller@13020000 {
> compatible = "starfive,jh7110-reset-sys";
> reg = <0x0 0x13020000 0x0 0x10000>;
> ...
> };
>
> What do you think of this approach? I would appreciate your suggestions.
>

We shouldn't have two different nodes with the same reg property. Please
ioremap in whatever driver probes and creates the auxiliary device(s)
and then pass the void __iomem * to it.