RE: [PATCH 1/1] dt-bindings: spi: Add separate binding for dh,dhcom-board

[Christoph Niedermaier <cniedermaier@dh-electronics.com>]

From: Marek Vasut <marex@nabladev.com>
Sent: Tuesday, October 20, 2026 4:41 PM
>>>>>>> +++ b/Documentation/devicetree/bindings/spi/dh,dhcom-board.yaml
>>>>>>> @@ -0,0 +1,46 @@
>>>>>>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
>>>>>>> +%YAML 1.2
>>>>>>> +---
>>>>>>> +$id: http://devicetree.org/schemas/spi/dh,dhcom-board.yaml#
>>>>>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>>>>>>> +
>>>>>>> +title: DH electronics GmbH on-board CPLD trivial SPI device
>>>>>>
>>>>>> This does not look quite right, since compatible this is used only on:
>>>>>>
>>>>>> arch/arm/boot/dts/imx6ull-dhcor-maveo-box.dts
>>>>>>
>>>>>>          model = "DH electronics i.MX6ULL DHCOR on maveo box";
>>>>>>          compatible = "marantec,imx6ull-dhcor-maveo-box",
>>>>>> "dh,imx6ull-dhcor-som",
>>>>>>
>>>>>> So the whole
>>>>>>
>>>>>>          spidev@0 {
>>>>>>                  compatible = "dh,dhcom-board";
>>>>>>                  reg = <0>;
>>>>>>                  spi-cpha;
>>>>>>                  spi-cpol;
>>>>>>                  spi-max-frequency = <54000000>;
>>>>>>          };
>>>>>>
>>>>>> Should probably use a different compatible.
>>>>>>
>>>>>> Christoph, what device is this on this board ?
>>
>> There is no device connected to these pins, only an extension connector.
>> The "dh,dhcom-board" device was used only to test the hardware and was
>> unfortunately forgotten to be removed. In the production version, no
>> device is connected to this interface. It should actually be removed.
>> Should I create a patch for this?
> 
> In that case, I would suggest to remove this whole spidev@0 from this DT
> with proper Fixes: tag .
> 
> [...]
> 
> >>> But in any case, the compatible string should likely be fixed here, this
> >>> does not seem right. The dh,dhcom-board was describing some CPLD/FPGA on one
> >>> of the evalboards.
> >>
> >> Ye I don't disagree there. "dhcom-board" seems not nearly specific
> >> enough about what the device is.
> >
> > There isn't actually a user for this device, see above. It's only used downstream
> > at DH electronics for a connection to a PSoC chip. But even for this purpose, it's
> > not being used correctly. What should we do now?
> I think this patch can also be dropped, the dh,dhcom-board would be left
> as a legacy compatible for the CPLD/FPGA on the DHCOM PDK2 board (where
> it is not described yet, but should be) , and the dh-dhcom-board should
> remain a trivial device, since the CPLD/FPGA is connected via some
> parallel bus if I recall it right ?

Yes, on the PDK2 the CPLD/FPGA is connected via a parallel bus.

Regards
Christoph