-----Original Message-----
From: Shawn Guo [mailto:shawnguo@kernel.org]
Sent: Tuesday, August 30, 2016 7:02 AM
To: Scott Wood <oss@buserror.net>
Cc: Bhaskar U <redacted>; devicetree@vger.kernel.org; Pratiyush Srivastava
[off-list ref]; Stuart Yoder [off-list ref]; Prabhakar Kushwaha
[off-list ref]; linux-devel@gforge.freescale.net; linux-arm-kernel@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:

quoted

On Mon, 2016-08-29 at 17:52 +0800, Shawn Guo wrote:

quoted

On Fri, Aug 26, 2016 at 03:57:21PM +0530, Bhaskar Upadhaya wrote:

quoted

+		clockgen: clocking@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