Re: [PATCH 1/3] clk: socfpga: agilex: convert to CLK_OF_DECLARE()

[Brian Masney <bmasney@redhat.com>]

Hi Dinh,

On Mon, Sep 21, 2026 at 11:59:50AM -0500, Dinh Nguyen wrote:
> On 9/21/26 09:52, Brian Masney wrote:
> > On Mon, Sep 21, 2026 at 11:17:13AM +0800, Ng, Adrian Ho Yin wrote:
> > > subsys_initcall() / subsys_platform_driver() would not fix the failure we
> > > are hitting. Both still run after time_init(), while the DW APB timer is
> > > registered via TIMER_OF_DECLARE from timer_probe().
> > > 
> > > So moving from core_initcall() to subsys_initcall() changes nothing for
> > > this consumer: the timer cannot defer, clk_get() still fails, and the timer
> > > is never brought up. That is why these patches use CLK_OF_DECLARE(): the
> > > provider must be registered from of_clk_init() so clocks exist before
> > > TIMER_OF_DECLARE runs.
> > > 
> > > On the broader point about CLK_OF_DECLARE abuse: I agree it should not be
> > > used merely to beat platform device probe. If the preferred approach is to
> > > keep the clkmgr as a platform driver (subsys_platform_driver()) and give the
> > > DW APB timer nodes a fixed clock-frequency instead of a clocks phandle, I
> > > can respin that way. Please let me know which you prefer.
> > 
> > I wanted confirmation that you wanted to use CLK_OF_DECLARE() for the
> > system timers.
> > 
> > Will you by chance be at Linux Plumbers Conference in two weeks? Bartosz
> > is leading a discussion about the future of CLK_OF_DECLARE() and
> > friends.
> > 
> > https://lpc.events/event/20/contributions/2503/
> > 
> > We want to minimize the use of CLK_OF_DECLARE(), so the preference is
> > to keep this as a platform driver if possible. If you are able to get
> > around using CLK_OF_DECLARE() by initially running the system timers
> > with a fixed frequency then I think that would be preferable.
> 
> I originally pushed back on hard-coding a fixed frequency for these timers
> because if the bootloader changed the frequency of the clocks for these
> timers, we may run in to a problem. But I don't think the bootloader had
> changed the clock frequency in a long time, so it may not really be a
> problem. But it just feels wrong to not take in a frequency from the clock
> driver.
> 
> The other option is perhaps adding the ability to defer probe these timers?

Lets see what comes out the discussion at LPC about CLK_OF_DECLARE() in
2+ weeks. I'll make sure to attend this particular discussion.

Brian