[EXT] Re: [PATCH v7 3/7] dt-bindings: i3c: Add NXP P3H2x4x i3c-hub support
Lakshay Piplani
lakshay.piplani at nxp.com
Sun Mar 22 21:38:24 PDT 2026
> -----Original Message-----
> From: Rob Herring <robh at kernel.org>
> Sent: Monday, March 23, 2026 5:05 AM
> To: Lakshay Piplani <lakshay.piplani at nxp.com>
> Cc: linux-kernel at vger.kernel.org; linux-i3c at lists.infradead.org;
> alexandre.belloni at bootlin.com; krzk+dt at kernel.org; conor+dt at kernel.org;
> devicetree at vger.kernel.org; broonie at kernel.org; lee at kernel.org; Frank Li
> <frank.li at nxp.com>; lgirdwood at gmail.com; Vikash Bansal
> <vikash.bansal at nxp.com>; Priyanka Jain <priyanka.jain at nxp.com>; Aman
> Kumar Pandey <aman.kumarpandey at nxp.com>
> Subject: [EXT] Re: [PATCH v7 3/7] dt-bindings: i3c: Add NXP P3H2x4x i3c-hub
> support
>
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> On Thu, Mar 19, 2026 at 04:54:37PM +0530, Lakshay Piplani wrote:
> > From: Aman Kumar Pandey <aman.kumarpandey at nxp.com>
> >
> > Add bindings for the NXP P3H2x4x (P3H2440/P3H2441/P3H2840/P3H2841)
> > multiport I3C hub family. These devices connect to a host via
> > I3C/I2C/SMBus and allow communication with multiple downstream
> > peripherals.
> >
> > Signed-off-by: Aman Kumar Pandey <aman.kumarpandey at nxp.com>
> > Signed-off-by: Vikash Bansal <vikash.bansal at nxp.com>
> >
> > ---
> > Changes in v7:
> > - Fix schema validation issues
> > - Adjust required properties
> > - Add I2C example
> >
> > Changes in v6:
> > - Use a vendor prefix for the attributes
> >
> > Changes in v5:
> > - Removed SW properties: cp0-ldo-microvolt,cp1-ldo-microvolt,
> > tp0145-ldo-microvolt, tp2367-ldo-microvolt
> > - Changed supply entries and its descriptions
> >
> > Changes in v4:
> > - Fixed DT binding check warning
> > - Removed SW properties: ibi-enable, local-dev, and always-enable
> >
> > Changes in v3:
> > - Added MFD (Multi-Function Device) support for I3C hub and on-die
> > regulator
> > - Added Regulator supply node
> >
> > Changes in v2:
> > - Fixed DT binding check warning
> > - Revised logic for parsing DTS nodes
> > ---
> > ---
> > .../devicetree/bindings/i3c/nxp,p3h2840.yaml | 303 ++++++++++++++++++
> > MAINTAINERS | 8 +
> > 2 files changed, 311 insertions(+)
> > create mode 100644
> > Documentation/devicetree/bindings/i3c/nxp,p3h2840.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/i3c/nxp,p3h2840.yaml
> > b/Documentation/devicetree/bindings/i3c/nxp,p3h2840.yaml
> > new file mode 100644
> > index 000000000000..495e0e4c1ae1
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/i3c/nxp,p3h2840.yaml
> > @@ -0,0 +1,303 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) # Copyright
> > +2025 NXP %YAML 1.2
> > +---
> > +$id:
> > +https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fdevi
> >
> +cetree.org%2Fschemas%2Fi3c%2Fnxp%2Cp3h2840.yaml%23&data=05%7C02
> %7Clak
> >
> +shay.piplani%40nxp.com%7C41cb77ab9e1a4bd9525208de886bab1b%7C686
> ea1d3b
> >
> +c2b4c6fa92cd99c5c301635%7C0%7C0%7C639098193138487662%7CUnknow
> n%7CTWFp
> >
> +bGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4
> zMiIsI
> >
> +kFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=ofJ5OTL%2Fn
> kxuq1Ky
> > +bU5RTJtwo4yMNFHvObf2iTFnaSg%3D&reserved=0
> > +$schema:
> > +https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fdevi
> > +cetree.org%2Fmeta-
> schemas%2Fcore.yaml%23&data=05%7C02%7Clakshay.pipla
> >
> +ni%40nxp.com%7C41cb77ab9e1a4bd9525208de886bab1b%7C686ea1d3bc2
> b4c6fa92
> >
> +cd99c5c301635%7C0%7C0%7C639098193138518717%7CUnknown%7CTWFp
> bGZsb3d8ey
> >
> +JFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoi
> TWF
> >
> +pbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=Oy7On%2FMYpy93DRw
> O243lEvJ%2F
> > +oCfusLv0j2e0S93cNnk%3D&reserved=0
> > +
> > +title: NXP P3H2X4X I3C HUB
> > +
> > +maintainers:
> > + - Aman Kumar Pandey <aman.kumarpandey at nxp.com>
> > + - Vikash Bansal <vikash.bansal at nxp.com>
> > +
> > +description: |
> > + P3H2x4x (P3H2440/P3H2441/P3H2840/P3H2841) is a family of multiport
> > +I3C
> > + hub devices that connect to:-
> > + 1. A host CPU via I3C/I2C/SMBus bus on upstream side and connect to
> multiple
> > + peripheral devices on the downstream side.
> > + 2. Have two Controller Ports which can support either
> > + I2C/SMBus or I3C buses and connect to a CPU, BMC or SOC.
> > + 3. P3H2840/ P3H2841 are 8 port I3C hub with eight I3C/I2C Target Port.
> > + 4. P3H2440/ P3H2441 are 4 port I3C hub with four I3C/I2C Target Port.
> > + Target ports can be configured as I2C/SMBus, I3C or GPIO and connect
> to
> > + peripherals.
> > +
> > +properties:
> > + compatible:
> > + const: nxp,p3h2840
> > +
> > + reg:
> > + maxItems: 1
> > +
> > + '#address-cells':
> > + const: 1
> > +
> > + '#size-cells':
> > + const: 0
> > +
> > + assigned-address:
> > + maximum: 0x7f
> > +
> > + nxp,tp0145-pullup-ohms:
> > + description:
> > + Selects the pull up resistance for target Port 0/1/4/5, in ohms.
> > + enum: [250, 500, 1000, 2000]
> > + default: 500
> > +
> > + nxp,tp2367-pullup-ohms:
> > + description:
> > + Selects the pull up resistance for target Port 2/3/6/7, in ohms.
> > + enum: [250, 500, 1000, 2000]
> > + default: 500
> > +
> > + nxp,cp0-io-strength-ohms:
> > + description:
> > + Selects the IO drive strength for controller Port 0, in ohms.
> > + enum: [20, 30, 40, 50]
> > + default: 20
> > +
> > + nxp,cp1-io-strength-ohms:
> > + description:
> > + Selects the IO drive strength for controller Port 1, in ohms.
> > + enum: [20, 30, 40, 50]
> > + default: 20
> > +
> > + nxp,tp0145-io-strength-ohms:
> > + description:
> > + Selects the IO drive strength for target port 0/1/4/5, in ohms.
> > + enum: [20, 30, 40, 50]
> > + default: 20
> > +
> > + nxp,tp2367-io-strength-ohms:
> > + description:
> > + Selects the IO drive strength for target port 2/3/6/7, in ohms.
> > + enum: [20, 30, 40, 50]
> > + default: 20
> > +
> > + vcc1-supply:
> > + description: Controller port 0 power supply.
> > +
> > + vcc2-supply:
> > + description: Controller port 1 power supply.
> > +
> > + vcc3-supply:
> > + description: Target port 0/1/4/5 power supply.
> > +
> > + vcc4-supply:
> > + description: Target port 2/3/6/7 power supply.
> > +
> > + regulators:
> > + type: object
> > + additionalProperties: false
> > +
> > + properties:
> > + ldo-cp0:
> > + type: object
> > + $ref: /schemas/regulator/regulator.yaml#
> > + unevaluatedProperties: false
> > +
> > + ldo-cp1:
> > + type: object
> > + $ref: /schemas/regulator/regulator.yaml#
> > + unevaluatedProperties: false
> > +
> > + ldo-tpg0:
> > + type: object
> > + $ref: /schemas/regulator/regulator.yaml#
> > + unevaluatedProperties: false
> > +
> > + ldo-tpg1:
> > + type: object
> > + $ref: /schemas/regulator/regulator.yaml#
> > + unevaluatedProperties: false
> > +
> > +required:
> > + - reg
> > +
> > +patternProperties:
> > + "^i3c@[0-7]$":
> > + type: object
> > + unevaluatedProperties: false
> > +
> > + properties:
> > + reg:
> > + description:
> > + The I3C HUB Target Port number.
> > + maximum: 7
> > +
> > + '#address-cells':
> > + const: 3
> > +
> > + '#size-cells':
> > + const: 0
> > +
> > + nxp,pullup-enable:
> > + type: boolean
> > + description:
> > + Enables the on-die pull-up for Target Port.
> > +
> > + required:
> > + - reg
> > + - "#address-cells"
> > + - "#size-cells"
> > +
> > + "^(i2c|smbus)@[0-7]$":
> > + type: object
> > + unevaluatedProperties: false
> > +
> > + properties:
> > + reg:
> > + description:
> > + The I3C HUB Target Port number.
> > + maximum: 7
> > +
> > + '#address-cells':
> > + const: 1
> > +
> > + '#size-cells':
> > + const: 0
> > +
> > + nxp,pullup-enable:
> > + type: boolean
> > + description:
> > + Enables the on-die pull-up for Target Port.
> > +
> > + required:
> > + - reg
> > + - "#address-cells"
> > + - "#size-cells"
> > +
> > +unevaluatedProperties: false
> > +
> > +examples:
> > + - |
> > + i3c {
> > + #address-cells = <3>;
> > + #size-cells = <0>;
> > +
> > + hub at 70,236153000c2 {
> > + reg = <0x70 0x236 0x3000c2>;
>
> Once again, you must have a compatible. "The device is discoverable" is not
> an argument. If it is discoverable, then don't put the device in DT in the first
> place.
>
> Rob
Hi Rob,
Thanks for pointing it out.
I've added the missing compatible in i3c example; will include it in v8.
Regards
Lakshay
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