[PATCH v2 1/1] arm64: Add DTS support for FSL's LS1012A SoC

[Stuart Yoder]

> -----Original Message-----
> From: Shawn Guo [mailto:shawnguo at kernel.org]
> Sent: Tuesday, August 30, 2016 7:02 AM
> To: Scott Wood <oss at buserror.net>
> Cc: Bhaskar U <bhaskar.upadhaya at nxp.com>; devicetree at vger.kernel.org; Pratiyush Srivastava
> <pratiyush.srivastava at nxp.com>; Stuart Yoder <stuart.yoder at nxp.com>; Prabhakar Kushwaha
> <prabhakar.kushwaha at nxp.com>; linux-devel at gforge.freescale.net; linux-arm-kernel at lists.infradead.org
> Subject: Re: [PATCH v2 1/1] arm64: Add DTS support for FSL's LS1012A SoC
> 
> On Mon, Aug 29, 2016 at 12:51:01PM -0500, Scott Wood wrote:
> > On Mon, 2016-08-29 at 17:52 +0800, Shawn Guo wrote:
> > > On Fri, Aug 26, 2016 at 03:57:21PM +0530, Bhaskar Upadhaya wrote:
> > > >
> > > > +		clockgen: clocking at 1ee1000 {
> > > > +			compatible = "fsl,ls1012a-clockgen";
> > > The compatible cannot be found in binding docs.
> >
> > From Documentation/devicetree/bindings/clock/qoriq-clock.txt:
> >
> > - compatible: Should contain a chip-specific clock block compatible
> >         string and (if applicable) may contain a chassis-version clock
> >         compatible string.
> >
> >         Chip-specific strings are of the form "fsl,<chip>-clockgen", such as:
> >         * "fsl,p2041-clockgen"
> >         * "fsl,p3041-clockgen"
> >         * "fsl,p4080-clockgen"
> >         * "fsl,p5020-clockgen"
> >         * "fsl,p5040-clockgen"
> >         * "fsl,t4240-clockgen"
> >         * "fsl,b4420-clockgen"
> >         * "fsl,b4860-clockgen"
> >         * "fsl,ls1021a-clockgen"
> >         Chassis-version clock strings include:
> >         * "fsl,qoriq-clockgen-1.0": for chassis 1.0 clocks
> >         * "fsl,qoriq-clockgen-2.0": for chassis 2.0 clocks
> >
> > I really hope we don't have to update every single fsl,<chip>-whatever binding
> > every time a new chip comes out.  There are already other chips not listed,
> > FWIW (e.g. t1040, t2080, ls1043a, and ls2080a).  That's why it says "such as".
> 
> If I remember correctly, DT maintainers want every supported compatible
> string explicitly listed in bindings doc.  And they even added a check
> into checkpatch.pl with commit bff5da433525 ("checkpatch: add DT
> compatible string documentation checks").

See Documentation/devicetree/bindings/submitting-patches.txt:

  5) The wildcard "<chip>" may be used in compatible strings, as in
     the following example:

         - compatible: Must contain '"nvidia,<chip>-pcie",
           "nvidia,tegra20-pcie"' where <chip> is tegra30, tegra132, ...

     As in the above example, the known values of "<chip>" should be
     documented if it is used.

It _is_ allowed to use the <chip> wildcard, and so you will not find all
full compatible strings explicitly listed in bindings.  However, the
chips themselves "should" be listed.

Thanks,
Stuart