Re: [PATCH 1/6] dt-bindings: iio: xilinx: Add Documentation for Sysmon

[Jonathan Cameron <jonathan.cameron@huawei.com>]

On Fri, 5 Sep 2025 10:41:44 +0200
Michal Simek <michal.simek@amd.com> wrote:

> From: Salih Erim <salih.erim@amd.com>
> 
> Add devicetree documentation for Xilinx Sysmon IP which is used for
> internal chip monitoring on Xilinx Versal SOCs.
> 
> Co-developed-by: Anand Ashok Dumbre <anand.ashok.dumbre@xilinx.com>
> Signed-off-by: Anand Ashok Dumbre <anand.ashok.dumbre@xilinx.com>
> Co-developed-by: Anish Kadamathikuttiyil Karthikeyan Pillai <anish.kadamathikuttiyil-karthikeyan-pillai@amd.com>
> Signed-off-by: Anish Kadamathikuttiyil Karthikeyan Pillai <anish.kadamathikuttiyil-karthikeyan-pillai@amd.com>
> Signed-off-by: Salih Erim <salih.erim@amd.com>
> Signed-off-by: Michal Simek <michal.simek@amd.com>
> ---
> 
>  .../bindings/iio/adc/xlnx,versal-sysmon.yaml  | 235 ++++++++++++++++++
>  1 file changed, 235 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/adc/xlnx,versal-sysmon.yaml
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/xlnx,versal-sysmon.yaml b/Documentation/devicetree/bindings/iio/adc/xlnx,versal-sysmon.yaml
> new file mode 100644
> index 000000000000..a768395cade7
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/xlnx,versal-sysmon.yaml
> @@ -0,0 +1,235 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/adc/xlnx,versal-sysmon.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Xilinx Versal Sysmon
> +
> +maintainers:
> +  - Salih Erim <salih.erim@amd.com>
> +
> +description:
> +  The Xilinx Sysmon provides on-chip monitoring and control for the supply
> +  voltages and temperatures across the chip. Since there are only 160 supply
> +  voltage registers and 184 measurement points, there is no constant mapping
> +  of supply voltage registers and the measurement points. User has to select
> +  the voltages to monitor in design tool. Depending on the selection, a voltage
> +  supply gets mapped to one of the supply registers. So, this mapping information
> +  is provided via description which contain the information of name of
> +   the supply enabled and the supply register it maps to.
> +
> +properties:
> +  compatible:
> +    items:
> +      - const: xlnx,versal-sysmon
> +
> +  reg:
> +    maxItems: 1
> +    description: Sysmon Registers.
> +
> +  interrupts:
> +    maxItems: 1
> +    description: Interrupt line for Sysmon.
> +
> +  '#address-cells':
> +    const: 1
> +
> +  '#size-cells':
> +    const: 0
> +
> +  '#io-channel-cells':
> +    const: 0
> +
> +  xlnx,hbm:
> +    type: boolean
> +    description:
> +      Exists if node refers to a HBM (High Bandwidth Memory) SLR (Super Logic Region).
> +
> +  xlnx,nodeid:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description:
> +      PLM specified sysmon node id.
> +
> +  xlnx,numaiechannels:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    minimum: 1
> +    maximum: 64
> +    description:
> +      Total number of sysmon satellites close to AI Engine exposed as channels.

Feels like some use - would make this easier to parse.  xlnx,num-aie-channels.
Similar to the next one. How is this related to the number of child nodes?


> +
> +  xlnx,numchannels:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    minimum: 1
> +    maximum: 160
> +    description:
> +      Number of supply channels enabled in the design.

Given you have subnodes called supplyxxx why is a count
of those needed or is this not counting those?

> +
> +patternProperties:
> +  "^supply@([0-9]{1,2}|1[0-5][0-9])$":
> +    type: object
> +    description:
> +      Represents the supplies configured in the design.
> +
> +    properties:
> +      reg:
> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        minimum: 0
> +        maximum: 159
> +        description:
> +          The supply number associated with the voltage.
> +
> +      xlnx,name:
> +        $ref: /schemas/types.yaml#/definitions/string
> +        description:
> +          Name of the supply enabled

Would the generic property "label" be useable here?

> +
> +      xlnx,bipolar:
> +        $ref: /schemas/types.yaml#/definitions/flag
> +        description:
> +          If the supply has a bipolar type and the output will be signed.

This is very generic.  We have it described for ADC channels already in
bindings/iio/adc/adc.yaml.  Why can't we use that here?
That binding does rely on matching against 'channel' for node names though.
Where a 'type of channel' has been relevant IIRC we've always added
a separate property rather than using the child node name.

> +
> +    required:
> +      - reg
> +      - xlnx,name
> +
> +    additionalProperties: false
> +
> +  "^temp@([1-9]|[1-5][0-9]|6[0-4])$":
> +    type: object
> +    description:
> +      Represents the sysmon temperature satellites.
> +
> +    properties:
> +      reg:
> +        minimum: 1
> +        maximum: 64
> +        description:
> +          The sysmon temperature satellite number.
> +
> +      xlnx,aie-temp:
> +        $ref: /schemas/types.yaml#/definitions/flag
> +        description:
> +          If present it indicates the temperature satellite is in
> +          close proximity with AI Engine

This one seems unusual.  I guess it makes a configuration difference
of some type.  I'll look at the code to see if that answers the question.

> +
> +      xlnx,name:
> +        $ref: /schemas/types.yaml#/definitions/string
> +        description:
> +          Name of temperature satellite exposed

As above. label tends to get used for things like this.

> +
> +    required:
> +      - reg
> +      - xlnx,name
> +
> +    additionalProperties: false
> +
> +required:
> +  - compatible
> +  - reg
> +  - xlnx,numchannels
> +
> +additionalProperties: false