Re: [PATCH v4 1/4] dt-bindings: mfd: Add bindings for Ampere Altra SMPro drivers

[Rob Herring <robh@kernel.org>]

On Thu, Apr 22, 2021 at 04:08:40PM +0700, Quan Nguyen wrote:
> Adds device tree bindings for SMPro driver found on the Mt.Jade hardware
> reference platform with Ampere's Altra Processor family.
> 
> The SMpro co-processor on Ampere Altra processor family is to monitor
> and report various data included hwmon-related info, RAS errors, and
> other miscellaneous information. This parent SMPro MFD driver creates
> a single simple register map to be shared by all sub-devices and leave
> all the specific to be handled by the child drivers.

Again, just because you have multiple functions aka MFD, that doesn't 
mean you need child nodes for each function. The only thing you have 
in DT is a register address. Does this vary? If so, how often? How many 
different versions of a DT do you currently or expect to have? 

> 
> Signed-off-by: Quan Nguyen <quan@os.amperecomputing.com>
> ---
> Changes in v4:
>   + Revised the commit message to clarify how the specific info will
>     be handled commented by Rob.
> 
> Changes in v3:
>   + Supported list of compatible string [Rob]
>   + Introduced reg property in DT to specify reg offset [Rob]
>   + Updated description and other minor changes in yaml file [Rob]
> 
> Changes in v2:
>   + Changed "ampere,ac01-smpro" to "ampere,smpro" [Quan]
> 
>  .../bindings/hwmon/ampere,ac01-hwmon.yaml     |  28 +++++
>  .../devicetree/bindings/mfd/ampere,smpro.yaml | 105 ++++++++++++++++++
>  2 files changed, 133 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/hwmon/ampere,ac01-hwmon.yaml
>  create mode 100644 Documentation/devicetree/bindings/mfd/ampere,smpro.yaml
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/ampere,ac01-hwmon.yaml b/Documentation/devicetree/bindings/hwmon/ampere,ac01-hwmon.yaml
> new file mode 100644
> index 000000000000..fbf7ec754160
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/ampere,ac01-hwmon.yaml
> @@ -0,0 +1,28 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/hwmon/ampere,ac01-hwmon.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Hardware monitoring driver for the Ampere Altra SMPro
> +
> +maintainers:
> +  - Quan Nguyen <quan@os.amperecomputing.com>
> +
> +description: |
> +  This module is part of the Ampere Altra SMPro multi-function device. For more
> +  details see ../mfd/ampere,smpro.yaml.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - ampere,ac01-hwmon
> +
> +  reg:
> +    maxItems: 1
> +
> +required:
> +  - compatible
> +  - reg
> +
> +additionalProperties: false
> diff --git a/Documentation/devicetree/bindings/mfd/ampere,smpro.yaml b/Documentation/devicetree/bindings/mfd/ampere,smpro.yaml
> new file mode 100644
> index 000000000000..5613c420869e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mfd/ampere,smpro.yaml
> @@ -0,0 +1,105 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/mfd/ampere,smpro.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Ampere Altra SMPro firmware driver
> +
> +maintainers:
> +  - Quan Nguyen <quan@os.amperecomputing.com>
> +
> +description: |
> +  Ampere Altra SMPro firmware may contain different blocks like hardware
> +  monitoring, error monitoring and other miscellaneous features.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - ampere,smpro
> +
> +  reg:
> +    description:
> +      I2C device address.
> +    maxItems: 1
> +
> +  "#address-cells":
> +    const: 1
> +
> +  "#size-cells":
> +    const: 0
> +
> +patternProperties:
> +  "^hwmon(@[0-9a-f]+)?$":
> +    $ref: ../hwmon/ampere,ac01-hwmon.yaml
> +
> +  "^misc(@[0-9a-f]+)?$":
> +    type: object
> +    description: |
> +      This module is part of the Ampere Altra SMPro multi-function device
> +      to support miscellaneous features
> +    properties:
> +      compatible:
> +        enum:
> +          - ampere,ac01-misc
> +      reg:
> +        maxItems: 1
> +
> +    required:
> +      - compatible
> +      - reg
> +
> +  "^errmon(@[0-9a-f]+)?$":
> +    type: object
> +    description: |
> +      This module is part of the Ampere Altra SMPro multi-function device
> +      that supports error monitoring feature.
> +
> +    properties:
> +      compatible:
> +        enum:
> +          - ampere,ac01-errmon
> +      reg:
> +        maxItems: 1
> +
> +    required:
> +      - compatible
> +      - reg
> +
> +required:
> +  - "#address-cells"
> +  - "#size-cells"
> +  - compatible
> +  - reg
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    i2c {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        smpro@4f {
> +            compatible = "ampere,smpro";
> +            reg = <0x4f>;
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +
> +            hwmon@10 {
> +                compatible = "ampere,ac01-hwmon";
> +                reg = <0x10>;
> +            };
> +
> +            misc@b0 {
> +                compatible = "ampere,ac01-misc";
> +                reg = <0xb0>;
> +            };
> +
> +            errmon@80 {
> +                compatible = "ampere,ac01-errmon";
> +                reg = <0x80>;
> +            };
> +
> +        };
> +    };
> -- 
> 2.28.0
>