diff mbox series

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

Message ID 20240426-dev-mule-i2c-mux-v1-2-045a482f6ffb@theobroma-systems.com (mailing list archive)
State New, archived
Headers show
Series Add Mule I2C multiplexer support | expand

Commit Message

Farouk Bouabid April 26, 2024, 4:49 p.m. UTC
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(+)

Comments

Rob Herring (Arm) April 26, 2024, 6:22 p.m. UTC | #1
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.
Krzysztof Kozlowski April 29, 2024, 6:27 a.m. UTC | #2
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
Rob Herring (Arm) April 29, 2024, 1:56 p.m. UTC | #3
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
Farouk Bouabid May 2, 2024, 12:14 p.m. UTC | #4
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
Farouk Bouabid May 2, 2024, 12:21 p.m. UTC | #5
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
diff mbox series

Patch

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