Mailing List Archive: [PATCH 2/7] dt-bindings: i2c: mux: mule: add dt-bindings for mule i2c multiplexer

[PATCH 2/7] dt-bindings: i2c: mux: mule: add dt-bindings for mule i2c multiplexer

Apr 26, 2024, 9:49 AM

Post #1 of 6 (8 views)

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>;
+ };
+ };
+ };
+ };
+...

--
2.34.1

Re: [PATCH 2/7] dt-bindings: i2c: mux: mule: add dt-bindings for mule i2c multiplexer [ In reply to ]

robh at kernel

Apr 26, 2024, 11:22 AM

Post #2 of 6 (8 views)

Permalink

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.

Re: [PATCH 2/7] dt-bindings: i2c: mux: mule: add dt-bindings for mule i2c multiplexer [ In reply to ]

krzysztof.kozlowski at linaro

Apr 28, 2024, 11:27 PM

Post #3 of 6 (7 views)

Permalink

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

Re: [PATCH 2/7] dt-bindings: i2c: mux: mule: add dt-bindings for mule i2c multiplexer [ In reply to ]

robh at kernel

Apr 29, 2024, 6:56 AM

Post #4 of 6 (7 views)

Permalink

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?

Rob

Re: [PATCH 2/7] dt-bindings: i2c: mux: mule: add dt-bindings for mule i2c multiplexer [ In reply to ]

farouk.bouabid at theobroma-systems

May 2, 2024, 5:14 AM

Post #5 of 6 (2 views)

Permalink

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

Re: [PATCH 2/7] dt-bindings: i2c: mux: mule: add dt-bindings for mule i2c multiplexer [ In reply to ]

farouk.bouabid at theobroma-systems

May 2, 2024, 5:21 AM

Post #6 of 6 (2 views)

Permalink

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