Re: [PATCH v7 2/4] dt-bindings: clock: sophgo: support SG2042

[Chen Wang]

On 2024/1/13 3:35, Samuel Holland wrote:
> Hi Conor, Chen,
>
> On 2024-01-11 10:58 AM, Conor Dooley wrote:
> > On Thu, Jan 11, 2024 at 04:00:04PM +0800, Chen Wang wrote:
> > > With this change, we describe the plls defined in system control as pllclk,
> > > as a child node of system controller. clkgen will use pllclk as "input"
> > > because pll clocks are parent of div clocks .
> > >
> > > But there is another remaining question about the gate clock. For those gate
> > > clocks controlled by CLOCK, no problem we will provide then in clkgen, but
> > > for those gate clocks controlled by registers in SYS_CTRL, they are child
> > > gate of the "clk_gate_rp_cpu_normal", which is a gate clock provided by
> > > clkgen. If I extracted those SYS_CTRL gate clocks and define them in system
> > > controller dts node, I may have to use "clk_gate_rp_cpu_normal" as their
> > > input, it looks a bit wierd becasue there are cases where each other serves
> > > as input. I try to draft below DTS to explan what I meant. I'm not sure if
> > > it can work and I'd love to hear your guidance.
> > I'm not sure how this sort of circular relationship works for probing
> > works either. Stephen etc would know more than me here.
> It generally works fine. The common clock framework can handle the child clock
> being registered before its parent, even when using a DT (fw_name) reference.
> See for example clk_core_fill_parent_index() and
> clk_core_reparent_orphans_nolock() in drivers/clk/clk.c
Learned and thank you.
> Regards,
> Samuel