Re: [PATCH v2 1/6] ARM: dra762: hwmod: Add MCAN support

From: Tony Lindgren
Date: Thu May 31 2018 - 11:26:34 EST


* Tero Kristo <t-kristo@xxxxxx> [180531 06:18]:
> On 30/05/18 18:54, Tony Lindgren wrote:
> > * Tero Kristo <t-kristo@xxxxxx> [180530 15:44]:
> > > On 30/05/18 18:28, Tony Lindgren wrote:
> > > > * Tero Kristo <t-kristo@xxxxxx> [180530 15:18]:
> > > > > For the OCP if part, I think that is still needed until we switch over to
> > > > > full sysc driver. clkctrl_offs you probably also need because that is used
> > > > > for mapping the omap_hwmod against a specific clkctrl clock. Those can be
> > > > > only removed once we are done with hwmod (or figure out some other way to
> > > > > assign the clkctrl clock to a hwmod.)
> > > >
> > > > Hmm might be worth testing. I thought your commit 70f05be32133
> > > > ("ARM: OMAP2+: hwmod: populate clkctrl clocks for hwmods if available")
> > > > already parses the clkctrl from dts?
> > >
> > > It maps the clkctrl clock to be used by hwmod, if those are available. We
> > > didn't add any specific clock entries to DT for mapping the actual clkctrl
> > > clock without the hwmod_data hints yet though, as that was deemed temporary
> > > solution only due to transition to interconnect driver. I.e., you would need
> > > something like this in DT for every device node:
> > >
> > > &uart3 {
> > > clocks = <l4per_clkctrl UART3_CLK 0>;
> > > clock-names = "clkctrl";
> > > };
> > >
> > > ... which is currently not present.
> >
> > Hmm is that not the "fck" clkctrl clock we have already in
> > the dts files for the interconnect target modules?
>
> Oh okay, yeah, we could parse that one, but currently it is not done, and is
> not present for everything either I believe.
>
> > We can also use pdata callbacks to pass the clock node if
> > needed. But I guess I don't quite still understand what we
> > are missing :)
>
> So, what is missing is the glue logic only from the hwmod codebase. Right
> now this is not supported but should be relatively trivial thing to add if
> we really want to do this.

OK let's think about this a bit for v4.19 then.

Regards,

Tony