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

Jonathan Cameron
2025-09-05T11:30:10Z

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