Re: [PATCH 1/3] clk: versatile: Switch to assigned clock parents

[Stephen Boyd]

On 08/03/2015 07:01 AM, Pawel Moll wrote:
> On Sat, 2015-08-01 at 00:44 +0100, Stephen Boyd wrote:
> > @@ -179,6 +124,15 @@ static void __init clk_sp810_of_setup(struct device_node *node)
> >   		sp810->timerclken[i].channel = i;
> >   		sp810->timerclken[i].hw.init = &init;
> >   
> > +		/*
> > +		 * If DT isn't setting the parent, force it to be
> > +		 * the 1 MHz clock without going through the framework.
> > +		 * We do this before clk_register() so that it can determine
> > +		 * the parent and setup the tree properly.
> > +		 */
> > +		if (deprecated)
> > +			init.ops->set_parent(&sp810->timerclken[i].hw, 1);
> > +
> >   		sp810->timerclken[i].clk = clk_register(NULL,
> >   				&sp810->timerclken[i].hw);
> >   		WARN_ON(IS_ERR(sp810->timerclken[i].clk));
> So that's one thing I've got a (small) problem here...
>
> The above change assumes that SP810 always have 32kHz clock on input 0
> and 1MHz clock on input 1. Yes, this is how it made on VExpress, but it
> doesn't have to be the case. The magic picking up the faster clock was
> added to handle all possible cases.
>
> The bottom line is: if all we care is VExpress than it works, but it's
> still a hack. Personally I don't like it, however I won't nak the patch
> because of this.

All current dts files in the kernel tree have 1MHz on input 1, so we 
make this change here to set the parent to input 1 if there isn't an 
assigned-clock-parents property. Presumably new dts files should have 
the new property so that things work properly. I tried to find the 
binding document, but it doesn't look to exist, so I didn't have 
anything to update.


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