Re: [PATCH v8 1/3] dt-bindings: i2c: Add Novatek NT72676 I2C controller

[Rob Herring <robh@kernel.org>]

On Wed, Sep 02, 2026 at 05:13:16PM +0800, nina_kuo@novatek.com.tw wrote:
> From: Ben Huang <Ben_Huang@novatek.com.tw>
> 
> Add Devicetree binding documentation for Novatek NT72676 I2C
> controller.
> 
> Signed-off-by: Ben Huang <Ben_Huang@novatek.com.tw>
> Signed-off-by: Nina Kuo <Nina_Kuo@novatek.com.tw>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
> ---
>  .../bindings/i2c/novatek,nt72676-i2c.yaml     | 90 +++++++++++++++++++
>  1 file changed, 90 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/i2c/novatek,nt72676-i2c.yaml
> 
> diff --git a/Documentation/devicetree/bindings/i2c/novatek,nt72676-i2c.yaml b/Documentation/devicetree/bindings/i2c/novatek,nt72676-i2c.yaml
> new file mode 100644
> index 000000000000..c9dd1c0d7957
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/i2c/novatek,nt72676-i2c.yaml
> @@ -0,0 +1,90 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/i2c/novatek,nt72676-i2c.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Novatek NT72676 I2C Controller
> +
> +maintainers:
> +  - Ben Huang <ben_huang@novatek.com.tw>
> +  - Jason JJ Wu <jason_jj_wu@novatek.com.tw>
> +
> +description:
> +  Novatek NT72676 SoC provides two I2C controller variants, generic I2C and
> +  STBC I2C.

blank line between paragraphs and you need a '>' modifier on 
'description'.

> +  The generic I2C controllers are accessible only by the host CPU and driven
> +  by a 96 MHz AHB clock.
> +  On the other hand, the STBC I2C controllers can be controlled by either the
> +  host CPU or STBC (Standby Controller, an 8051-based microcontroller) and
> +  driven by a 12 MHz STBC clock. Authentication with STBC is required before
> +  the host CPU can access the STBC I2C controller registers.

Is the programming model of the I2C controller different? If not, the 
compatible should be the same.

> +
> +properties:
> +  compatible:
> +    enum:
> +      - novatek,nt72676-i2c
> +      - novatek,nt72676-stbc-i2c
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 1
> +
> +  clock-frequency:
> +    default: 100000
> +    enum: [ 100000, 400000 ]
> +
> +  novatek,stbc-syscon:
> +    $ref: /schemas/types.yaml#/definitions/phandle
> +    description:
> +      Phandle to the STBC system controller registers used to authenticate
> +      host access and switch ownership of the STBC I2C controller.

Sounds like this could be modelled as a hwlock? That's other platforms 
mediate access to shared h/w. We really only want to have these syscon 
phandles as a last resort.

Rob