Re: [PATCH RFC 1/3] dt-bindings: iio: imu: add Open Sensor Fusion UART binding

[Conor Dooley <conor@kernel.org>]

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On Wed, May 20, 2026 at 04:28:41PM +0900, Jinseob Kim wrote:
> Add a binding for a UART-attached Open Sensor Fusion device.
> 
> The device is exposed as a serdev child node using the
> opensensorfusion,osf-uart compatible string.

> Keep Raspberry Pi overlay and
> test notes outside the binding.

This should not be in the commit message, it's not relevant info.

> The binding has been checked with dt_binding_check.

This is a requirement, there's no reason to state it in the commit
message.

> 
> Signed-off-by: Jinseob Kim <kimjinseob88@gmail.com>
> ---
>  .../iio/imu/opensensorfusion,osf-uart.yaml    | 33 +++++++++++++++++++
>  1 file changed, 33 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/imu/opensensorfusion,osf-uart.yaml
> 
> diff --git a/Documentation/devicetree/bindings/iio/imu/opensensorfusion,osf-uart.yaml b/Documentation/devicetree/bindings/iio/imu/opensensorfusion,osf-uart.yaml
> new file mode 100644
> index 000000000..6f329c326
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/imu/opensensorfusion,osf-uart.yaml

I find it hard to believe that this is an "imu". It sounds more like
this is a bus or remoteproc than anything else.

> @@ -0,0 +1,33 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/imu/opensensorfusion,osf-uart.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Open Sensor Fusion UART Sensor Aggregation Device
> +
> +maintainers:
> +  - Jinseob Kim <kimjinseob88@gmail.com>
> +
> +description: |
> +  Open Sensor Fusion is a UART-attached sensor aggregation device. The device

What actually is this device?
Googling "open sensor fusion" gives me
https://github.com/memsindustrygroup/Open-Source-Sensor-Fusion
and
https://www.nxp.com/company/about-nxp/smarter-world-blog/BL-OPEN-SOURCE-SENSOR-FUSION
but neither of these explain to me what sort of device we are looking at
here. Seems as if it is not /a/ device at all, but could be one of many
devices, provided that they implement the other side of the protocol?

> +  exposes an OSF protocol v0 data stream over its host UART interface and may

What does "v0" mean here? Is the data format not complete yet?
Are versions of the protocol likely to be backwards compatible?
Will the device identify what version of the protocol it implements?

> +  report capabilities and samples for multiple sensor classes.

Yeah, then definitely this is not an "imu".

> +
> +properties:
> +  compatible:
> +    const: opensensorfusion,osf-uart

If this is some sort of remote processor slaved to the os, it seems possible
that the may be required to do turn its power or reset it somehow. Having
nothing but a compatible seems incomplete to me but I have no idea what
the complete set of properties would actually be.

Probably a good bit of discussion is needed here, but for now:
pw-bot: changes-requested

Thanks,
Conor.

> +
> +required:
> +  - compatible
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    serial {
> +        sensor {
> +            compatible = "opensensorfusion,osf-uart";
> +        };
> +    };
> +...
> -- 
> 2.43.0
> 
> 

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