Re: [PATCH 1/2] dt-bindings: probe-control: add probe control driver

[Krzysztof Kozlowski <krzk@kernel.org>]

On 11/09/2024 16:23, Nayeemahmed Badebade wrote:
> Device tree binding document for the probe-control driver

Describe the hardware, not driver...

> 
> Signed-off-by: Toyama Yoshihiro <yoshihiro.toyama@sony.com>
> Signed-off-by: Nayeemahmed Badebade <nayeemahmed.badebade@sony.com>
> ---
>  .../probe-control/linux,probe-controller.yaml | 59 +++++++++++++++++++
>  1 file changed, 59 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/probe-control/linux,probe-controller.yaml
> 
> diff --git a/Documentation/devicetree/bindings/probe-control/linux,probe-controller.yaml b/Documentation/devicetree/bindings/probe-control/linux,probe-controller.yaml
> new file mode 100644
> index 000000000000..1945a7a5ab3c
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/probe-control/linux,probe-controller.yaml
> @@ -0,0 +1,59 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright (c) 2024 Sony Group Corporation
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/linux,probe-controller.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Probe control device
> +
> +maintainers:
> +  - Nayeemahmed Badebade <nayeemahmed.badebade@sony.com>
> +  - Toyama Yoshihiro <yoshihiro.toyama@sony.com>
> +
> +description: |
> +  This binding is for controlling the probes of a set of devices in the system.
> +  Probe control device is a dummy device that can be used to control the probe
> +  of a group of devices. To have finer control, the devices can further be
> +  divided into multiple groups and for each group a probe control device can
> +  be assigned. This way, individual groups can be managed independently.
> +  For example, one group can be for pcie based devices and other can be
> +  scsi or usb devices.
> +  Probe control device is provider node and the devices whose probes need to be
> +  controlled, are consumer nodes. To establish control over consumer device
> +  probes, each consumer device node need to refer the probe control provider
> +  node by the phandle.

So all this looks like not suitable for DT at all.

> +
> +properties:
> +  compatible:
> +    const: linux,probe-control
> +
> +  probe-control-supply:
> +    description:
> +      Phandle to the probe control provider node.

I don't understand this. Regulator supply is not a provider node.

> +
> +required:
> +  - compatible
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    // The node below defines a probe control device/provider node
> +    prb_ctrl_dev_0: prb_ctrl_dev_0 {

No underscores in node names.

> +        compatible = "linux,probe-control";

Where are the resources? It's empty?

> +    };
> +
> +    // The node below is the consumer device node that refers to provider
> +    // node by its phandle and a result will not be probed until provider
> +    // node is probed.
> +    pcie@1ffc000 {
> +        reg = <0x01ffc000 0x04000>, <0x01f00000 0x80000>;
> +        #address-cells = <3>;
> +        #size-cells = <2>;
> +        device_type = "pci";
> +        ranges = <0x81000000 0 0          0x01f80000 0 0x00010000>,
> +                 <0x82000000 0 0x01000000 0x01000000 0 0x00f00000>;
> +
> +        probe-control-supply = <&prb_ctrl_dev_0>;
> +    };

Best regards,
Krzysztof