Re: [PATCH v2] clk: keystone: sci-clk: Adding support for non contiguous clocks

[Kumar, Udit]

On 2/6/2024 7:56 PM, CHANDRU DHAVAMANI wrote:
> On 06/02/24 19:45, Kumar, Udit wrote:
> > On 2/6/2024 7:24 PM, Kamlesh Gurudasani wrote:
> > > Nishanth Menon <nm@xxxxxx> writes:
> > >
> > > > On 16:13-20240206, Udit Kumar wrote:
> > > > > Most of clocks and their parents are defined in contiguous range,
> > > > > But in few cases, there is gap in clock numbers[0].
> > > > > Driver assumes clocks to be in contiguous range, and add their clock
> > > > > ids incrementally.
> > > > >
> > > > > New firmware started returning error while calling get_freq and is_on
> > > > > API for non-available clock ids.
> > > > >
> > > > > In this fix, driver checks and adds only valid clock ids.
> > > > >
> > > > > Fixes: 3c13933c6033 ("clk: keystone: sci-clk: add support for 
> > > > > dynamically probing clocks")
> > > > >
> > > > > [0] 
> > > > > https://software-dl.ti.com/tisci/esd/latest/5_soc_doc/j7200/clocks.html 
> > > > >
> > > > > Section Clocks for NAVSS0_CPTS_0 Device,
> > > > > clock id 12-15 not present.
> > > > >
> > > > > Signed-off-by: Udit Kumar <u-kumar1@xxxxxx>
> > > > >                   while (num_parents--) {
> > > > > +                    /* Check if this clock id is valid */
> > > > > +                    ret = provider->ops->get_freq(provider->sci,
> > > > > +                        sci_clk->dev_id, clk_id, &freq);
> > > > get_freq is a bit expensive as it has to walk the clock tree to find
> > > > the clock frequency (at least the first time?). just wondering if
> > > > there is lighter alternative here?
> > > How about get_clock? Doesn't read the registers at least.
> >
> > Said API needs, some flags to be passed,
> >
> > Can those flag be set to zero, Chandru ?
>
>
> get_clock doesn't require any flags to be passed.


May be firmware does not need it but  I was referring to

https://elixir.bootlin.com/linux/latest/source/drivers/clk/keystone/sci-clk.c#L78



> > > Regards,
> > > Kamlesh