An extension of the RTL9300 SoC is to support multiplexing by selecting
the SDA pins that are being used dynamically. Add a binding that allows
us to describe hardware that makes use of this.
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
---
.../bindings/i2c/realtek,rtl9300-i2c-mux.yaml | 82 +++++++++++++++++++
MAINTAINERS | 1 +
2 files changed, 83 insertions(+)
create mode 100644 Documentation/devicetree/bindings/i2c/realtek,rtl9300-i2c-mux.yaml
diff --git a/Documentation/devicetree/bindings/i2c/realtek,rtl9300-i2c-mux.yaml b/Documentation/devicetree/bindings/i2c/realtek,rtl9300-i2c-mux.yaml
new file mode 100644
index 000000000000..a64879d0fda7
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/realtek,rtl9300-i2c-mux.yaml
@@ -0,0 +1,82 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/i2c/realtek,rtl9300-i2c-mux.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Realtek RTL I2C Multiplexer
+
+maintainers:
+ - Chris Packham <chris.packham@alliedtelesis.co.nz>
+
+description: |
+ The I2C controllers on the RTL9300 support a level of multiplexing. In the
+ simple case the rtl9300-i2c binding can provide a single SDA pin per
+ controller. This binding allows a more than one SDA line to be used per
+ controller providing a level of multiplexing.
+
+properties:
+ compatible:
+ const: realtek,rtl9300-i2c-mux
+
+ i2c-parent:
+ description: phandle of the I2C bus controller that this multiplexer
+ operates on.
+ $ref: /schemas/types.yaml#/definitions/phandle
+
+allOf:
+ - $ref: i2c-mux.yaml
+
+unevaluatedProperties: false
+
+required:
+ - compatible
+ - i2c-parent
+
+examples:
+ - |
+ switch@1b000000 {
+ compatible = "realtek,rtl9302c-switch", "syscon", "simple-mfd";
+ reg = <0x1b000000 0x10000>;
+
+ i2c0: i2c@36c {
+ compatible = "realtek,rtl9300-i2c";
+ realtek,control-offset = <0x36c>;
+ realtek,global-control-offset = <0x384>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ };
+ };
+
+ base {
+ i2c-mux {
+ compatible = "realtek,rtl9300-i2c-mux";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ i2c-parent = <&i2c0>;
+
+ i2c@0 {
+ reg = <0>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ gpio@20 {
+ compatible = "nxp,pca9555";
+ gpio-controller;
+ #gpio-cells = <2>;
+ reg = <0x20>;
+ };
+ };
+
+ i2c@2 {
+ reg = <2>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ gpio@20 {
+ compatible = "nxp,pca9555";
+ gpio-controller;
+ #gpio-cells = <2>;
+ reg = <0x20>;
+ };
+ };
+ };
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index 9e123e9839a5..178ac8a7e843 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19891,6 +19891,7 @@ RTL9300 I2C DRIVER (rtl9300-i2c)
M: Chris Packham <chris.packham@alliedtelesis.co.nz>
L: linux-i2c@vger.kernel.org
S: Maintained
+F: Documentation/devicetree/bindings/i2c/realtek,rtl9300-i2c-mux.yaml
F: Documentation/devicetree/bindings/i2c/realtek,rtl9300-i2c.yaml
F: drivers/i2c/busses/i2c-rtl9300.c
--
2.46.1On Wed, Sep 18, 2024 at 11:29:31AM +1200, Chris Packham wrote:
> An extension of the RTL9300 SoC is to support multiplexing by selecting
> the SDA pins that are being used dynamically. Add a binding that allows
> us to describe hardware that makes use of this.
>
> Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
> ---
> .../bindings/i2c/realtek,rtl9300-i2c-mux.yaml | 82 +++++++++++++++++++
> MAINTAINERS | 1 +
> 2 files changed, 83 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/i2c/realtek,rtl9300-i2c-mux.yaml
>
> diff --git a/Documentation/devicetree/bindings/i2c/realtek,rtl9300-i2c-mux.yaml b/Documentation/devicetree/bindings/i2c/realtek,rtl9300-i2c-mux.yaml
> new file mode 100644
> index 000000000000..a64879d0fda7
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/i2c/realtek,rtl9300-i2c-mux.yaml
> @@ -0,0 +1,82 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/i2c/realtek,rtl9300-i2c-mux.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Realtek RTL I2C Multiplexer
> +
> +maintainers:
> + - Chris Packham <chris.packham@alliedtelesis.co.nz>
> +
> +description: |
> + The I2C controllers on the RTL9300 support a level of multiplexing. In the
> + simple case the rtl9300-i2c binding can provide a single SDA pin per
> + controller. This binding allows a more than one SDA line to be used per
> + controller providing a level of multiplexing.
> +
> +properties:
> + compatible:
> + const: realtek,rtl9300-i2c-mux
> +
> + i2c-parent:
> + description: phandle of the I2C bus controller that this multiplexer
> + operates on.
> + $ref: /schemas/types.yaml#/definitions/phandle
The mux isn't a separate device, so I think this should just be part of
the i2c parent:
i2c-mux@36c {
i2c@0 {
...
};
i2c@1 {
...
};
...
};
And then you can get rid of the SDA pin property. If you only use 1 pin,
then there is just 1 'i2c' child node with an address matching the SDA
pin.
Rob
On Wed, 18 Sep 2024 11:29:31 +1200, Chris Packham wrote: > An extension of the RTL9300 SoC is to support multiplexing by selecting > the SDA pins that are being used dynamically. Add a binding that allows > us to describe hardware that makes use of this. > > Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> > --- > .../bindings/i2c/realtek,rtl9300-i2c-mux.yaml | 82 +++++++++++++++++++ > MAINTAINERS | 1 + > 2 files changed, 83 insertions(+) > create mode 100644 Documentation/devicetree/bindings/i2c/realtek,rtl9300-i2c-mux.yaml > My bot found errors running 'make dt_binding_check' on your patch: yamllint warnings/errors: dtschema/dtc warnings/errors: Documentation/devicetree/bindings/i2c/realtek,rtl9300-i2c-mux.example.dts:22.25-28.13: Warning (unit_address_vs_reg): /example-0/switch@1b000000/i2c@36c: node has a unit name, but no reg or ranges property Documentation/devicetree/bindings/i2c/realtek,rtl9300-i2c-mux.example.dtb: /example-0/switch@1b000000: failed to match any schema with compatible: ['realtek,rtl9302c-switch', 'syscon', 'simple-mfd'] doc reference errors (make refcheckdocs): See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20240917232932.3641992-5-chris.packham@alliedtelesis.co.nz The base for the series is generally the latest rc1. A different dependency should be noted in *this* patch. If you already ran 'make dt_binding_check' and didn't see the above error(s), then make sure 'yamllint' is installed and dt-schema is up to date: pip3 install dtschema --upgrade Please check and re-submit after running the above command yourself. Note that DT_SCHEMA_FILES can be set to your schema file to speed up checking your schema. However, it must be unset to test all examples with your schema.
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