Re: [PATCH 1/2] dt-bindings: (pmbus/lx1308) Add LX1308 support

[Brian Chiang]

On Thu, Apr 23, 2026 at 10:41:18AM +0200, Krzysztof Kozlowski wrote:
> On Wed, Apr 22, 2026 at 12:06:15PM +0000, Brian Chiang wrote:
> > Add device tree bindings for the Luxshare LX1308, a high-efficiency
> > 12V 860W DC/DC power module with PMBus interface.
> >
> > Signed-off-by: Brian Chiang <chiang.brian@xxxxxxxxxxxx>
> > ---
> >  .../bindings/hwmon/pmbus/luxshare,lx1308.yaml      | 49 ++++++++++++++++++++++
> >  .../devicetree/bindings/vendor-prefixes.yaml       |  2 +
> >  MAINTAINERS                                        |  8 ++++
> >  3 files changed, 59 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/hwmon/pmbus/luxshare,lx1308.yaml b/Documentation/devicetree/bindings/hwmon/pmbus/luxshare,lx1308.yaml
> > new file mode 100644
> > index 000000000000..a8d92447508d
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/hwmon/pmbus/luxshare,lx1308.yaml
> > @@ -0,0 +1,49 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +
>
> Drop blank line here

Will fix in v2.

> > +$id: http://devicetree.org/schemas/hwmon/pmbus/luxshare,lx1308.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Luxshare LX1308 Digital DC/DC Power Module
> > +
> > +maintainers:
> > +  - Brian Chiang <chiang.brian@xxxxxxxxxxxx>
> > +
> > +description: |
>
> Do not need '|' unless you need to preserve formatting.

Will drop the '|' in v2.

> > +  The LX1308 is a high-efficiency, non-isolated, regulated 12V, 860W,
> > +  digital DC/DC power module. The module operates from a 40V to 60V DC
> > +  primary bus and provides a 12V regulated output voltage. It can deliver
> > +  up to 860W continuous and 1300W in transient.
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - luxshare,lx1308lch
> > +      - luxshare,lx1308nch
> > +      - luxshare,lx1308sch
> > +      - luxshare,lx1308ldh
> > +      - luxshare,lx1308ndh
> > +      - luxshare,lx1308sdh
> > +      - luxshare,lx1308
>
> What are all these devices? What are the differences?
>
> Especially, what is the difference between lx1308sdh and lx1308?

Thanks for catching this. The suffix letters encode purely
mechanical/packaging options with no software visibility:

  1st letter - pin length    (S=0.11", N=0.145", L=0.17")
  2nd letter - pin assignment (C=pin14 IShare, D=pin14 NC,
                               S=pin9/14 used as Vo sense)
  3rd letter - HSP option    (H=HSP, O=open frame)
  4th letter - output cap    (blank=600uF, C=2000uF)

All variants share the same PMBus register map, scaling, and behavior.

> > +
> > +  reg:
> > +    maxItems: 1
>
> No properties? Looks like suitable for trivial bundings.

Agreed. Since there are no device-specific properties and software-wise
this is a single device, I will drop the standalone binding in v2 and
add a single entry to trivial-devices.yaml:

  - description: Luxshare LX1308 12V/860W digital DC/DC power module
    compatible: luxshare,lx1308

The mechanical variant information will be documented in
Documentation/hwmon/lx1308.rst (sent in patch 2/2) so integrators can
still find it, without polluting the ABI.

> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    i2c {
> > +      #address-cells = <1>;
> > +      #size-cells = <0>;
> > +
> > +      power-module@60 {
> > +        compatible = "luxshare,lx1308";
> > +        reg = <0x60>;
> > +      };
> > +    };
> > diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
> > index ee7fd3cfe203..67fb1592daaa 100644
> > --- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
> > +++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
> > @@ -967,6 +967,8 @@ patternProperties:
> >      description: Shenzhen Luckfox Technology Co., Ltd.
> >    "^lunzn,.*":
> >      description: Shenzhen Lunzn Technology Co., Ltd.
> > +  "^luxshare,.*":
> > +    description: Luxshare-ICT Co., Ltd.
> >    "^luxul,.*":
> >      description: Lagrand | AV
> >    "^lwn,.*":
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index c3fe46d7c4bc..58fa595cff6a 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -15175,6 +15175,14 @@ S:	Maintained
> >  F:	Documentation/devicetree/bindings/iio/light/liteon,ltr390.yaml
> >  F:	drivers/iio/light/ltr390.c
> >
> > +LUXSHARE LX1308 PMBUS DRIVER
> > +M:	Brian Chiang <chiang.brian@xxxxxxxxxxxx>
> > +L:	linux-hwmon@xxxxxxxxxxxxxxx
> > +S:	Maintained
> > +F:	Documentation/devicetree/bindings/hwmon/pmbus/luxshare,lx1308.yaml
>
>
> > +F:	Documentation/hwmon/lx1308.rst
> > +F:	drivers/hwmon/pmbus/lx1308.c
>
> There are no such files

These files are added in patch 2/2 of this series:
https://lore.kernel.org/lkml/20260422-add-support-lx1308-v1-0-9b8322f45aae@xxxxxxxxxxxx/

I will note the series ordering more clearly in the v2 cover letter.

> Best regards,
> Krzysztof

Thanks for the review.

Best regards,
Brian