[PATCH 2/6] dt-bindings: clk: mstar msc313 mpll binding description

Stephen Boyd sboyd at kernel.org
Tue Feb 9 21:29:30 EST 2021


Quoting Daniel Palmer (2020-12-21 00:51:56)
> Hi Stephen,
> 
> On Mon, 21 Dec 2020 at 03:44, Stephen Boyd <sboyd at kernel.org> wrote:
> >
> > Quoting Daniel Palmer (2020-12-19 22:35:41)
> > > Hi Stephen,
> > >
> > > On Sun, 20 Dec 2020 at 12:39, Stephen Boyd <sboyd at kernel.org> wrote:
> > > > > +  clock-output-names:
> > > > > +    minItems: 8
> > > > > +    maxItems: 8
> > > > > +    description: |
> > > > > +      This should provide a name for the internal PLL clock and then
> > > > > +      a name for each of the divided outputs.
> > > >
> > > > Is this necessary?
> > >
> > > I found without the names specified in the dt probing of muxes that
> > > depend on the outputs but appear earlier didn't work.
> > > Also this same PLL layout seems to be used in some other places so
> > > eventually I was thinking this driver would get used for those PLLs
> > > with different output names.
> >
> > Still seems like it could be auto-generated based on dev_name() +
> > number.
> 
> At one point I had something similar to that where the output names
> were generated at probe.
> Without the clock outputs listed in the device tree clock muxes that
> source clocks from the mpll couldn't probe properly as they couldn't
> look up all of their parents if they probed before the mpll.
> Maybe I'm doing something wrong there? I couldn't find a way to always
> resolve all of the parents or defer the probe of the muxes until the
> mpll clocks are registered.
> 

The child clks should be using clk_parent_data to point to the parent
clks through DT. That way the name of the clk doesn't matter except for
debug purposes.



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