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

[Bhaskar U]

>-----Original Message-----
>From: Scott Wood
>Sent: Tuesday, September 06, 2016 10:36 PM
>To: Shawn Guo <shawnguo at kernel.org>; Stuart Yoder <stuart.yoder at nxp.com>;
>Rob Herring <robh+dt at kernel.org>; Mark Rutland <mark.rutland at arm.com>
>Cc: devicetree at vger.kernel.org; Bhaskar U <bhaskar.upadhaya at nxp.com>; Scott
>Wood <oss at buserror.net>; Prabhakar Kushwaha
><prabhakar.kushwaha at nxp.com>; linux-devel at gforge.freescale.net; Pratiyush
>Srivastava <pratiyush.srivastava at nxp.com>; linux-arm-
>kernel at lists.infradead.org
>Subject: Re: [linux-devel] [PATCH v2 1/1] arm64: Add DTS support for FSL's
>LS1012A SoC
>
>On 09/04/2016 08:47 PM, Shawn Guo wrote:
>> On Tue, Aug 30, 2016 at 02:07:17PM +0000, Stuart Yoder wrote:
>>>> 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.
>>
>> + Rob and Mark
>>
>> Oops, I'm not aware of this DT document.  In that case, the DT
>> document and checkpatch is basically asking for conflicting thing.
>> Rob, Mark, can you guys please clarify?
>
>Checkpatch is a useful tool but it can't get everything right all the time.
>

So what should we do, shall I add "compatible = "fsl,ls1012a-clockgen";" in Documentation/devicetree/bindings/clock/qoriq-clock.txt ?

>-Scott