Re: [PATCH v2] dt-bindings: mips: lantiq: Document lantiq dcdc binding

Aleksander Jan Bajkowski
2025-08-15T16:46:29Z

On 8/15/25 17:48, Conor Dooley wrote:
> On Fri, Aug 15, 2025 at 12:13:41PM +0200, Aleksander Jan Bajkowski wrote:
>> Hi Conor,
>>
>> On 8/14/25 22:48, Conor Dooley wrote:
>>> On Thu, Aug 14, 2025 at 10:26:56AM +0200, Aleksander Jan Bajkowski wrote:
>>>> Lantiq DCDC is a voltage converter with a voltage sensor.
>>>>
>>>> Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
>>>> ---
>>>> .../mips/lantiq/lantiq,dcdc-xrx200.yaml | 32 +++++++++++++++++++
>>>> 1 file changed, 32 insertions(+)
>>>> create mode 100644 Documentation/devicetree/bindings/mips/lantiq/lantiq,dcdc-xrx200.yaml
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/mips/lantiq/lantiq,dcdc-xrx200.yaml b/Documentation/devicetree/bindings/mips/lantiq/lantiq,dcdc-xrx200.yaml
>>>> new file mode 100644
>>>> index 000000000000..5648b9676b3c
>>>> --- /dev/null
>>>> +++ b/Documentation/devicetree/bindings/mips/lantiq/lantiq,dcdc-xrx200.yaml
>>>> @@ -0,0 +1,32 @@
>>>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
>>>> +%YAML 1.2
>>>> +---
>>>> +$id: http://devicetree.org/schemas/mips/lantiq/lantiq,dcdc-xrx200.yaml#
>>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>>>> +
>>>> +title: Lantiq DCDC (DC-DC converter with voltage sensor)
>>>> +
>>>> +maintainers:
>>>> + - Aleksander Jan Bajkowski <olek2@wp.pl>
>>>> +
>>>> +properties:
>>>> + compatible:
>>>> + items:
>>>> + - enum:
>>>> + - lantiq,dcdc-xrx200
>>> What is "xrx2000" in this context?
>>
>> “xrx200” is one of the generations of Lantiq SoCs. It includes four part
>> numbers
>> with the same memory map. The other generations are amazon-se, danube,
>> ARX100,
>> GRX100, xRX200, xRX300, xRX330. These correspond to the internal code names:
>> ase,
>> danube, ar9, gr9, vr9, ar10, grx390.
> And the dc-dc converter is part of the SoC?
> Either way, you've got this file in the wrong location probably, dc-dc
> converters are usually under the regulator directory.

The converter is inside the SoC. This driver only reads the voltage and
prints it at startup. The voltage supplied by this converter powers one
of the power domains. It powers the CPU core and probably other
peripherals as well. The voltage is programmed by the bootloader and
Linux never touches it.