Re: [PATCH 11/13] clk: renesas: rzg2l-cpg: drop determine_rate op and use CLK_ROUNDING_FW_MANAGED flag

[Brian Masney <bmasney@redhat.com>]

Hi Biju,

On Fri, Feb 27, 2026 at 03:23:19PM +0000, Biju Das wrote:
> > -----Original Message-----
> > From: Geert Uytterhoeven <geert@linux-m68k.org>
> > Sent: 27 February 2026 15:09
> > Subject: Re: [PATCH 11/13] clk: renesas: rzg2l-cpg: drop determine_rate op and use
> > CLK_ROUNDING_FW_MANAGED flag
> > 
> > On Fri, 27 Feb 2026 at 16:01, Brian Masney <bmasney@redhat.com> wrote:
> > > On Fri, Feb 27, 2026 at 09:20:09AM +0100, Geert Uytterhoeven wrote:
> > > > On Thu, 26 Feb 2026 at 19:18, Brian Masney <bmasney@redhat.com> wrote:
> > > > > This clk driver has a noop determine_rate clk op. Drop this empty
> > > > > function, and enable the CLK_ROUNDING_FW_MANAGED flag.
> > > > >
> > > > > Signed-off-by: Brian Masney <bmasney@redhat.com>
> > > >
> > > > Thanks for your patch!
> > > >
> > > > > --- a/drivers/clk/renesas/rzg2l-cpg.c
> > > > > +++ b/drivers/clk/renesas/rzg2l-cpg.c
> > 
> > > > > @@ -1041,7 +1034,7 @@ rzg2l_cpg_sipll5_register(const struct cpg_core_clk *core,
> > > > >         init.name = core->name;
> > > > >         parent_name = __clk_get_name(parent);
> > > > >         init.ops = &rzg2l_cpg_sipll5_ops;
> > > > > -       init.flags = 0;
> > > > > +       init.flags = CLK_ROUNDING_FW_MANAGED;
> > > >
> > > > Iff this is the Right Thing To Do (TM), it needs a comment, as this
> > > > clock is not managed by firmware.
> > >
> > > Before I start a larger discussion on patch 1 with more people about a
> > > name for this flag, help me understand why this provider has a noop
> > > determine rate. Is the hardware eventually programmed with a rate
> > > that's close enough to what was passed in? Or it doesn't really matter
> > > what the clock rate is, just as long as it is running? Or should the
> > > determine_rate function be filled out in this particular case?
> > 
> > I'd like to defer to Biju, who added the empty round^Wdetermine rate function.
> 
> PLL is capable of generating any frequency. that is the reason.
> 
> But we could, call rzg2l_cpg_get_foutpostdiv_rate() from determine_rate()
> as modified rzg2l_cpg_get_foutpostdiv_rate()[1] can return errors
> 
> [1]
> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/clk/renesas/rzg2l-cpg.c?h=next-20260227#n590

OK. So how do you all want to proceed here?

Do you want to fill out the determine rate in this driver? If so, we can
just drop this particular patch from this series.

Since the PLL is capable of any frequency, do you want to keep the empty
determine rate functionality? If so, we could use a different name for
this flag. Maybe CLK_ROUNDING_NOOP?

Brian