Re: [v4 3/5] dt-bindings: hwmon: Add bindings for aspeed tach controller

[Guenter Roeck]

On 11/22/22 22:16, Billy Tsai wrote:
> Add the aspeed tach device bindings which should be the child-node of
> pwm-tach mfd.
>
> Signed-off-by: Billy Tsai <billy_tsai@xxxxxxxxxxxxxx>
> ---
>   .../bindings/hwmon/aspeed,ast2600-tach.yaml   | 36 +++++++++++++++++++
>   1 file changed, 36 insertions(+)
>   create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed,ast2600-tach.yaml
>
> diff --git a/Documentation/devicetree/bindings/hwmon/aspeed,ast2600-tach.yaml b/Documentation/devicetree/bindings/hwmon/aspeed,ast2600-tach.yaml
> new file mode 100644
> index 000000000000..f42114f8e3c2
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/aspeed,ast2600-tach.yaml
> @@ -0,0 +1,36 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright (C) 2021 Aspeed, Inc.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/hwmon/aspeed,ast2600-tach.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Aspeed Ast2600 Tach controller
> +
> +maintainers:
> +  - Billy Tsai <billy_tsai@xxxxxxxxxxxxxx>
> +
> +description: |
> +  The Aspeed Tach controller can support upto 16 fan input.
> +  This module is part of the ast2600-pwm-tach multi-function device. For more
> +  details see ../mfd/aspeed,ast2600-pwm-tach.yaml.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - aspeed,ast2600-tach
> +patternProperties:
> +  "^fan@[a-z0-9]+$":
> +    type: object
> +    properties:
> +      reg:
> +        description:
> +          The tach channel used for this node.
> +        maxItems: 1
> +    required:
> +      - reg
> +
> +required:
> +  - compatible
> +
> +additionalProperties: false

I am not a devicetree expert, but I have to say I find it confusing that
there is no clear explanation that this is for a single fan channel
which is really a child of aspeed,ast2600-tach. An example might be
helpful.

Guenter