Re: [PATCH 4/7] spi: pl022: attempt to get sspclk by name

Arnd Bergmann
2014-02-11T15:48:29Z

On Tuesday 11 February 2014 15:04:38 Russell King - ARM Linux wrote:
> On Tue, Feb 11, 2014 at 03:08:06PM +0100, Arnd Bergmann wrote:
> > On Tuesday 11 February 2014, Mark Brown wrote:
> > > On Tue, Feb 11, 2014 at 11:37:09AM +0000, Mark Rutland wrote:
> > >
> > > > - pl022->clk = devm_clk_get(&adev->dev, NULL);
> > > > + /*
> > > > + * For compatibility with old DTBs and platform data, fall back to the
> > > > + * first clock if there's not an explicitly named "sspclk" entry.
> > > > + */
> > > > + pl022->clk = devm_clk_get(&adev->dev, "sspclk");
> > > > + if (IS_ERR(pl022->clk))
> > > > + pl022->clk = devm_clk_get(&adev->dev, NULL);
> > > > +
> > >
> > > I'll just have a bit of a grumble here and point out that this sort of
> > > stuff always worries me with the convention of using nameless clocks -
> > > it causes hassle adding further clocks.
> >
> > I think the best solution for this is to continue with anonymous clocks
> > rather than adding names after the fact. This could be done (for DT-only
> > drivers) using the of_clk_get() interface that takes an index, or
> > we could add a generic dev_clk_get_index() or similar interface that
> > has the same behavior but also works for clkdev.
>
> Mixing devm_* and non-devm_* interfaces doesn't work. If you want to do
> that, devm_of_clk_get() would be a prerequisit.

Yes, good point. So if we want to do it, we would have to add a new
function anyway, there is just the question whether it should be
devm_of_clk_get() or devm_clk_get_index() if that can also work for
non-DT devices. Do you think the latter actually makes sense in
the clkdev interfaces? I'm not familiar enough with the code to
tell how that would be implemented in a reasonable way.

Arnd