This patch adds support for the Mule I2C multiplexer.
Mule is an mcu that emulates a set of i2c devices which are reacheable
through an i2c-mux.
The emulated devices share a single i2c address with the mux itself where
the requested register is what determines which logic is executed (mux or
device).
Signed-off-by: Farouk Bouabid <farouk.bouabid@theobroma-systems.com>
---
.../devicetree/bindings/i2c/i2c-mux-mule.yaml | 80 ++++++++++++++++++++++
1 file changed, 80 insertions(+)
diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-mule.yaml b/Documentation/devicetree/bindings/i2c/i2c-mux-mule.yaml
new file mode 100644
index 000000000000..458e4661cbc8
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-mux-mule.yaml
@@ -0,0 +1,80 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/i2c/i2c-mux-mule.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Mule I2C multiplexer
+
+maintainers:
+ - Farouk Bouabid <farouk.bouabid@theobroma-systems.com>
+ - Quentin Schulz <quentin.schulz@theobroma-systems.com>
+
+description: |
+ Mule is an mcu that emulates a set of i2c devices which are reacheable
+ through an i2c-mux.
+
+ The emulated devices share a single i2c address with the mux itself where
+ the requested register is what determines which logic is executed (mux or
+ device)
+
+ +--------------------------------------------------+
+ | Mule |
+ | +---------------+ |
+ ------+->|Config register|----+ |
+ | | +---------------+ | |
+ | | V_ |
+ | | | \ +--------+ |
+ | | | \-------->| dev #0 | |
+ | | | | +--------+ |
+ | | | M |-------->| dev #1 | |
+ | +--------------------->| U | +--------+ |
+ | | X |-------->| dev #2 | |
+ | | | +--------+ |
+ | | /-------->| dev #3 | |
+ | |__/ +--------+ |
+ +--------------------------------------------------+
+
+
+allOf:
+ - $ref: /schemas/i2c/i2c-mux.yaml#
+
+properties:
+ compatible:
+ const: tsd,mule-i2c-mux
+
+ reg:
+ maxItems: 1
+
+required:
+ - compatible
+ - reg
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ i2c {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ i2c-mux@18 {
+ compatible = "tsd,mule-i2c-mux";
+ reg = <0x18>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ i2c@0 {
+ reg = <0x0>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ fan: fan@18 {
+ compatible = "ti,amc6821";
+ reg = <0x18>;
+ #cooling-cells = <2>;
+ };
+ };
+ };
+ };
+...
--
2.34.1On Fri, Apr 26, 2024 at 11:50 AM Farouk Bouabid <farouk.bouabid@theobroma-systems.com> wrote: > > This patch adds support for the Mule I2C multiplexer. > > Mule is an mcu that emulates a set of i2c devices which are reacheable MCU reachable > through an i2c-mux. > > The emulated devices share a single i2c address with the mux itself where > the requested register is what determines which logic is executed (mux or > device). Just to be sure, we need a complete binding for the MCU. Is this the only thing the MCU does? Rob
Hi Rob, On 29.04.24 15:56, Rob Herring wrote: > On Fri, Apr 26, 2024 at 11:50 AM Farouk Bouabid > <farouk.bouabid@theobroma-systems.com> wrote: >> This patch adds support for the Mule I2C multiplexer. >> >> Mule is an mcu that emulates a set of i2c devices which are reacheable > MCU > > reachable > >> through an i2c-mux. >> >> The emulated devices share a single i2c address with the mux itself where >> the requested register is what determines which logic is executed (mux or >> device). > Just to be sure, we need a complete binding for the MCU. Is this the > only thing the MCU does? Currently that is all the MCU does. We plan to add more features to the MCU firmware: Buzzer over i2c, watchdog over i2c ... Best regards Farouk
Except that this was not fully tested few comments. A nit, subject: drop second/last, redundant "dt-bindings for". The "dt-bindings" prefix is already stating that these are bindings. See also: https://elixir.bootlin.com/linux/v6.7-rc8/source/Documentation/devicetree/bindings/submitting-patches.rst#L18 On 26/04/2024 18:49, Farouk Bouabid wrote: > This patch adds support for the Mule I2C multiplexer. Please do not use "This commit/patch/change", but imperative mood. See longer explanation here: https://elixir.bootlin.com/linux/v5.17.1/source/Documentation/process/submitting-patches.rst#L95 > > Mule is an mcu that emulates a set of i2c devices which are reacheable > through an i2c-mux. > > The emulated devices share a single i2c address with the mux itself where > the requested register is what determines which logic is executed (mux or > device). > > Signed-off-by: Farouk Bouabid <farouk.bouabid@theobroma-systems.com> > --- > .../devicetree/bindings/i2c/i2c-mux-mule.yaml | 80 ++++++++++++++++++++++ > 1 file changed, 80 insertions(+) > > diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-mule.yaml b/Documentation/devicetree/bindings/i2c/i2c-mux-mule.yaml > new file mode 100644 > index 000000000000..458e4661cbc8 > --- /dev/null > +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-mule.yaml Use compatible as filename. > @@ -0,0 +1,80 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/i2c/i2c-mux-mule.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Mule I2C multiplexer > + > +maintainers: > + - Farouk Bouabid <farouk.bouabid@theobroma-systems.com> > + - Quentin Schulz <quentin.schulz@theobroma-systems.com> > + > +description: | > + Mule is an mcu that emulates a set of i2c devices which are reacheable typo, reachable > + through an i2c-mux. > + > + The emulated devices share a single i2c address with the mux itself where > + the requested register is what determines which logic is executed (mux or > + device) > + > + +--------------------------------------------------+ > + | Mule | > + | +---------------+ | > + ------+->|Config register|----+ | > + | | +---------------+ | | > + | | V_ | > + | | | \ +--------+ | > + | | | \-------->| dev #0 | | > + | | | | +--------+ | > + | | | M |-------->| dev #1 | | > + | +--------------------->| U | +--------+ | > + | | X |-------->| dev #2 | | > + | | | +--------+ | > + | | /-------->| dev #3 | | > + | |__/ +--------+ | > + +--------------------------------------------------+ > + > + > +allOf: > + - $ref: /schemas/i2c/i2c-mux.yaml# > + > +properties: > + compatible: > + const: tsd,mule-i2c-mux > + > + reg: > + maxItems: 1 > + Best regards, Krzysztof
On Fri, 26 Apr 2024 18:49:33 +0200, Farouk Bouabid wrote: > This patch adds support for the Mule I2C multiplexer. > > Mule is an mcu that emulates a set of i2c devices which are reacheable > through an i2c-mux. > > The emulated devices share a single i2c address with the mux itself where > the requested register is what determines which logic is executed (mux or > device). > > Signed-off-by: Farouk Bouabid <farouk.bouabid@theobroma-systems.com> > --- > .../devicetree/bindings/i2c/i2c-mux-mule.yaml | 80 ++++++++++++++++++++++ > 1 file changed, 80 insertions(+) > My bot found errors running 'make dt_binding_check' on your patch: yamllint warnings/errors: dtschema/dtc warnings/errors: /builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/i2c/i2c-mux-mule.example.dtb: fan@18: '#cooling-cells' does not match any of the regexes: 'pinctrl-[0-9]+' from schema $id: http://devicetree.org/schemas/trivial-devices.yaml# doc reference errors (make refcheckdocs): See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20240426-dev-mule-i2c-mux-v1-2-045a482f6ffb@theobroma-systems.com 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.
Hi Rob, On 26.04.24 20:22, Rob Herring wrote: > On Fri, 26 Apr 2024 18:49:33 +0200, Farouk Bouabid wrote: >> This patch adds support for the Mule I2C multiplexer. >> >> Mule is an mcu that emulates a set of i2c devices which are reacheable >> through an i2c-mux. >> >> The emulated devices share a single i2c address with the mux itself where >> the requested register is what determines which logic is executed (mux or >> device). >> >> Signed-off-by: Farouk Bouabid <farouk.bouabid@theobroma-systems.com> >> --- >> .../devicetree/bindings/i2c/i2c-mux-mule.yaml | 80 ++++++++++++++++++++++ >> 1 file changed, 80 insertions(+) >> > My bot found errors running 'make dt_binding_check' on your patch: > > yamllint warnings/errors: > > dtschema/dtc warnings/errors: > /builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/i2c/i2c-mux-mule.example.dtb: fan@18: '#cooling-cells' does not match any of the regexes: 'pinctrl-[0-9]+' Currently ti,amc6821 uses trivial devices dt-bindings which does not support "#cooling-cells". We can fix this in a different patch though. Best regards Farouk
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