Re: [PATCH] dt-bindings: i2c: Add yaml for Spreadtrum I2C controller

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 31/10/2023 09:08, Huangzheng Lai wrote:
> Add yaml file to replace txt file, and added description and
> example of reset attribute for Spreadtrum I2C controller.
> 
> Signed-off-by: Huangzheng Lai <Huangzheng.Lai@unisoc.com>
> ---
>  .../devicetree/bindings/i2c/i2c-sprd.txt      | 31 --------
>  .../devicetree/bindings/i2c/i2c-sprd.yaml     | 79 +++++++++++++++++++

Filename matching compatible.

>  2 files changed, 79 insertions(+), 31 deletions(-)
>  delete mode 100644 Documentation/devicetree/bindings/i2c/i2c-sprd.txt
>  create mode 100644 Documentation/devicetree/bindings/i2c/i2c-sprd.yaml
> 
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-sprd.txt b/Documentation/devicetree/bindings/i2c/i2c-sprd.txt
> deleted file mode 100644
> index 7b6b3b8d0d11..000000000000
> --- a/Documentation/devicetree/bindings/i2c/i2c-sprd.txt
> +++ /dev/null
> @@ -1,31 +0,0 @@
> -I2C for Spreadtrum platforms
> -
> -Required properties:
> -- compatible: Should be "sprd,sc9860-i2c".
> -- reg: Specify the physical base address of the controller and length
> -  of memory mapped region.
> -- interrupts: Should contain I2C interrupt.
> -- clock-names: Should contain following entries:
> -  "i2c" for I2C clock,
> -  "source" for I2C source (parent) clock,
> -  "enable" for I2C module enable clock.
> -- clocks: Should contain a clock specifier for each entry in clock-names.
> -- clock-frequency: Contains desired I2C bus clock frequency in Hz.
> -- #address-cells: Should be 1 to describe address cells for I2C device address.
> -- #size-cells: Should be 0 means no size cell for I2C device address.
> -
> -Optional properties:
> -- Child nodes conforming to I2C bus binding
> -
> -Examples:
> -i2c0: i2c@70500000 {
> -	compatible = "sprd,sc9860-i2c";
> -	reg = <0 0x70500000 0 0x1000>;
> -	interrupts = <GIC_SPI 11 IRQ_TYPE_LEVEL_HIGH>;
> -	clock-names = "i2c", "source", "enable";
> -	clocks = <&clk_i2c3>, <&ext_26m>, <&clk_ap_apb_gates 11>;
> -	clock-frequency = <400000>;
> -	#address-cells = <1>;
> -	#size-cells = <0>;
> -};
> -
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-sprd.yaml b/Documentation/devicetree/bindings/i2c/i2c-sprd.yaml
> new file mode 100644
> index 000000000000..54378afe8419
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/i2c/i2c-sprd.yaml
> @@ -0,0 +1,79 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright 2020 Unisoc Inc.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/i2c/i2c-sprd.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Unisoc I2C Controller Device
> +
> +maintainers:
> +  - Huangzheng Lai <laihuangzheng@gmail.com>
> +

Missing ref to i2c-controller. Open existing bindings and use them as
template instead of making something on your own with known bugs.

> +properties:
> +  compatible:
> +    items:

You can drop the items.

> +      - const: sprd,sc9860-i2c
> +
> +  reg:
> +    maxItems: 2

You need to describe the items (items with description)

> +
> +  interrupts:
> +    maxItems: 1
> +
> +  clock-names:
> +    items:
> +      - const: i2c
> +      - const: source
> +      - const: enable
> +
> +  clocks:
> +    items:
> +      - description: Clock specifier for "i2c" in clock-names

This description is useless and redundant. Instead, say what clock is
it. If you do not know, then just maxItems: 3

> +      - description: Clock specifier for "source" in clock-names
> +      - description: Clock specifier for "enable" in clock-names
> +
> +  clock-frequency:
> +    description: Constains desired I2C bus clock frequency in Hz

Typo, Contains

> +
> +  "#address-cells":
> +    const: 1
> +    description: Address cells for I2C device address

Drop, why do you need it?

> +
> +  "#size-cells":
> +    const: 0
> +    description: Size cell for I2C device address

Drop

> +
> +  reset-names:
> +    const: i2c_rst

Drop, wasn't in original binding. Or explain in commit msg what you
changed and why.

> +
> +  resets:
> +    maxItems: 1
> +    description: Phandle to the reset controller.

Drop, wasn't in original binding. Or explain in commit msg what you
changed and why.

Description is also quite redundant/useless.


> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +  - clock-names
> +  - clocks
> +  - "#address-cells"
> +  - "#size-cells"

Really... Open existing bindings.

> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    i2c0: i2c@2240000 {
> +      compatible = "sprd,sc9860-i2c";
> +      reg = <0 0x2240000 0 0x1000>;
> +      interrupts = <11>;
> +      clock-names = "i2c", "source", "enable";
> +      clocks = <&clk_i2c3>, <&ext_26m>, <&clk_ap_apb_gates 11>;
> +      clock-frequency = <400000>;
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +      reset-names = "i2c_rst";
> +      resets = <&apahb_gate 3>;

Incomplete. Add child node.

> +    };
> +

Best regards,
Krzysztof