Re: [PATCH v3 1/4] dt-bindings: mfd: Add bindings for Ampere Altra SMPro drivers

From: Rob Herring <robh@kernel.org>
To: Quan Nguyen <quan@os.amperecomputing.com>
Cc: Joel Stanley <joel@jms.id.au>, Andrew Jeffery <andrew@aj.id.au>,
	Jean Delvare <jdelvare@suse.com>,
	Guenter Roeck <linux@roeck-us.net>,
	Lee Jones <lee.jones@linaro.org>,
	Jonathan Corbet <corbet@lwn.net>,
	linux-hwmon@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
	linux-aspeed@lists.ozlabs.org, openbmc@lists.ozlabs.org,
	Open Source Submission <patches@amperecomputing.com>,
	Phong Vo <phong@os.amperecomputing.com>,
	"Thang Q . Nguyen" <thang@os.amperecomputing.com>
Subject: Re: [PATCH v3 1/4] dt-bindings: mfd: Add bindings for Ampere Altra SMPro drivers
Date: Tue, 13 Apr 2021 08:49:06 -0500	[thread overview]
Message-ID: <20210413134906.GA1538655@robh.at.kernel.org> (raw)
In-Reply-To: <20210409031332.21919-2-quan@os.amperecomputing.com>

On Fri, Apr 09, 2021 at 10:13:29AM +0700, Quan Nguyen wrote:
> Adds device tree bindings for SMPro drivers found on the Mt.Jade hardware
> reference platform with Ampere's Altra Processor family.
> 
> Signed-off-by: Quan Nguyen <quan@os.amperecomputing.com>
> ---
>  .../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

Again, not very specific. There's only 1 version of 'smpro' h/w or 
firmware? Are the firmware version and features discoverable? If not, 
you need to be more specific (or better yet, make them discoverable).

> +
> +  reg:
> +    description:
> +      I2C device address.
> +    maxItems: 1
> +
> +  "#address-cells":
> +    const: 1
> +
> +  "#size-cells":
> +    const: 0
> +
> +patternProperties:
> +  "^hwmon(@[0-9a-f]+)?$":
> +    $ref: ../hwmon/ampere,ac01-hwmon.yaml
> +
> +  "^misc(@[0-9a-f]+)?$":

You don't need these child nodes in DT if there are no resources 
associated with them. The parent driver can instantiate all the 
sub-functions.

> +    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
> 