On Fri, Dec 12, 2025 at 01:43:37PM -0600, Shenwei Wang wrote: > Remote processors may announce multiple devices (e.g., I2C, GPIO) over > an RPMSG channel.
Which channel does that happen on? > These devices may require corresponding device tree > nodes, especially when acting as providers, to supply phandles for their > consumers. > > Define an RPMSG node to work as a container for a group of RPMSG channels > under the imx_rproc node. > > Each subnode within "rpmsg" represents an individual RPMSG channel. The > name of each subnode corresponds to the channel name as defined by the > remote processor. > > All remote devices associated with a given channel are defined as child > nodes under the corresponding channel node. > > Signed-off-by: Shenwei Wang <[email protected]> > --- > .../devicetree/bindings/gpio/gpio-rpmsg.yaml | 49 +++++++++++++++++ > .../bindings/remoteproc/fsl,imx-rproc.yaml | 54 +++++++++++++++++++ > 2 files changed, 103 insertions(+) > create mode 100644 Documentation/devicetree/bindings/gpio/gpio-rpmsg.yaml > > diff --git a/Documentation/devicetree/bindings/gpio/gpio-rpmsg.yaml > b/Documentation/devicetree/bindings/gpio/gpio-rpmsg.yaml > new file mode 100644 > index 000000000000..b3e1a5dbf731 > --- /dev/null > +++ b/Documentation/devicetree/bindings/gpio/gpio-rpmsg.yaml > @@ -0,0 +1,49 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/gpio/gpio-rpmsg.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Generic GPIO driver over RPMSG The driver doesn't go over RPMSG. It's a GPIO provider or protocol. > + > +maintainers: > + - Shenwei Wang <[email protected]> > + > +description: > + On an AMP platform, some GPIO controllers are exposed by the remote > processor > + through the RPMSG bus. The RPMSG GPIO transport protocol defines the packet > + structure and communication flow between Linux and the remote firmware. > Those > + controllers are managed via this transport protocol. Got a reference to where any of this is defined? > + > +properties: > + compatible: > + oneOf: > + - items: > + - enum: > + - fsl,rpmsg-gpio > + - const: rpmsg-gpio > + - const: rpmsg-gpio > + > + reg: > + maxItems: 1 I still don't understand how 'reg' is determined. You may have explained it previously, but *this* patch needs to make me understand. > + > + "#gpio-cells": > + const: 2 > + > + gpio-controller: true > + > + interrupt-controller: true > + > + "#interrupt-cells": > + const: 2 > + > +required: > + - compatible > + - reg > + - "#gpio-cells" > + - "#interrupt-cells" > + > +allOf: > + - $ref: /schemas/gpio/gpio.yaml# > + > +unevaluatedProperties: false > diff --git a/Documentation/devicetree/bindings/remoteproc/fsl,imx-rproc.yaml > b/Documentation/devicetree/bindings/remoteproc/fsl,imx-rproc.yaml > index 57d75acb0b5e..fd8e5a61a459 100644 > --- a/Documentation/devicetree/bindings/remoteproc/fsl,imx-rproc.yaml > +++ b/Documentation/devicetree/bindings/remoteproc/fsl,imx-rproc.yaml > @@ -84,6 +84,33 @@ properties: > This property is to specify the resource id of the remote processor in > SoC > which supports SCFW > > + rpmsg: > + type: object > + additionalProperties: false > + description: > + Present a group of RPMSG channel devices. > + > + properties: > + rpmsg-io-channel: > + type: object > + additionalProperties: false > + properties: > + '#address-cells': > + const: 1 > + > + '#size-cells': > + const: 0 > + > + patternProperties: > + "gpio@[0-9a-f]+$": > + type: object > + $ref: /schemas/gpio/gpio-rpmsg.yaml# > + unevaluatedProperties: false > + > + required: > + - '#address-cells' > + - '#size-cells' > + > required: > - compatible > > @@ -146,5 +173,32 @@ examples: > &mu 3 1>; > memory-region = <&vdev0buffer>, <&vdev0vring0>, <&vdev0vring1>, > <&rsc_table>; > syscon = <&src>; > + > + rpmsg { What's the purpose of this node? Is it going to contain things other than "rpmsg io channels"? > + rpmsg-io-channel { > + #address-cells = <1>; > + #size-cells = <0>; > + > + gpio@0 { > + compatible = "rpmsg-gpio"; > + reg = <0>; > + gpio-controller; > + #gpio-cells = <2>; > + #interrupt-cells = <2>; > + interrupt-controller; > + interrupt-parent = <&rpmsg_gpioa>; > + }; > + > + gpio@1 { > + compatible = "rpmsg-gpio"; > + reg = <1>; > + gpio-controller; > + #gpio-cells = <2>; > + #interrupt-cells = <2>; > + interrupt-controller; > + interrupt-parent = <&rpmsg_gpiob>; > + }; > + }; > + }; > }; > ... > -- > 2.43.0 >
