Re: [PATCH 1/2] arm64: dts: ls1028a: add missing CAN nodes

From: Michael Walle
Date: Fri Sep 25 2020 - 05:31:53 EST


Am 2020-09-24 17:53, schrieb Leo Li:
-----Original Message-----
From: Michael Walle <michael@xxxxxxxx>
Sent: Thursday, September 24, 2020 6:31 AM
To: Leo Li <leoyang.li@xxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-
kernel@xxxxxxxxxxxxxxx; linux-can@xxxxxxxxxxxxxxx; Shawn Guo
<shawnguo@xxxxxxxxxx>; Rob Herring <robh+dt@xxxxxxxxxx>; Marc Kleine-
Budde <mkl@xxxxxxxxxxxxxx>; Joakim Zhang <qiangqing.zhang@xxxxxxx>
Subject: Re: [PATCH 1/2] arm64: dts: ls1028a: add missing CAN nodes

Am 2020-09-24 02:35, schrieb Leo Li:
>> -----Original Message-----
>> From: Michael Walle <michael@xxxxxxxx>
>> Sent: Wednesday, September 23, 2020 4:57 AM
>> To: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx;
>> linux-
>> kernel@xxxxxxxxxxxxxxx; linux-can@xxxxxxxxxxxxxxx
>> Cc: Shawn Guo <shawnguo@xxxxxxxxxx>; Leo Li <leoyang.li@xxxxxxx>;
Rob
>> Herring <robh+dt@xxxxxxxxxx>; Marc Kleine-Budde
<mkl@xxxxxxxxxxxxxx>;
>> Joakim Zhang <qiangqing.zhang@xxxxxxx>; Michael Walle
>> <michael@xxxxxxxx>
>> Subject: [PATCH 1/2] arm64: dts: ls1028a: add missing CAN nodes
>>
>> The LS1028A has two FlexCAN controller. These are compatible with the
>> ones
>> from the LX2160A. Add the nodes.
>>
>> The first controller was tested on the Kontron sl28 board.
>>
>> Signed-off-by: Michael Walle <michael@xxxxxxxx>
>> ---
>> arch/arm64/boot/dts/freescale/fsl-ls1028a.dtsi | 18
>> ++++++++++++++++++
>> 1 file changed, 18 insertions(+)
>>
>> diff --git a/arch/arm64/boot/dts/freescale/fsl-ls1028a.dtsi
>> b/arch/arm64/boot/dts/freescale/fsl-ls1028a.dtsi
>> index 0efeb8fa773e..807ee921ec12 100644
>> --- a/arch/arm64/boot/dts/freescale/fsl-ls1028a.dtsi
>> +++ b/arch/arm64/boot/dts/freescale/fsl-ls1028a.dtsi
>> @@ -386,6 +386,24 @@
>> status = "disabled";
>> };
>>
>> + can0: can@2180000 {
>> + compatible = "fsl,ls1028ar1-flexcan", "fsl,lx2160ar1-
>> flexcan";
>
> The explicit compatible strings cannot be found in the binding, but
> matched by the "fsl,<processor>-flexcan" pattern in the binding. Is
> this considered to be acceptable now?

What is the consequence if it is not acceptable? replacing the pattern
with individual compatible strings?

There is a recommendation in the kernel documentation quoted below:

7) 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.

But I am not sure if this is still a hard requirement. If so, we
should list the processors in the binding.

Marc, I'd convert this to yaml format, may I put your name as the
maintainer in the binding?

-michael