Re: [PATCH v4 1/2] dt-bindings: i2c: Add Synopsys DWC_i2c controller

[Krzysztof Kozlowski <krzk@kernel.org>]

On Tue, Oct 27, 2026 at 05:00:35PM +0530, Aniket Limaye wrote:
> Add documentation for the Synopsys Advanced I2C (DWC_i2c) controller, as
> found on the TI TDA54 SoC.
> 
> The block cannot work on its own and needs SoC integration, e.g. the
> FIFO depths are not discoverable from the IP. Do not add a generic
> compatible and only list SoC specific compatibles. The file is named
> after the IP so that other SoCs integrating it can be added here.
> 
> Signed-off-by: Aniket Limaye <a-limaye@ti.com>
> 
> ---
> 

Here you mention dependency on new dtschema (unreleased), since the
property was added a few days ago.

> Changes in v4:
> - Drop the approach of extending the existing i2c-designware-* driver
>   with a MODEL_TI_TDA54 variant. Instead, add a new standalone driver
>   (i2c-dwc-adv.c) and a new binding (snps,dwc-adv-i2c.yaml), since
>   DWC_i2c is not register compatible with DW_apb_i2c. (Andy Shevchenko)
> - Drop the snps,tx-fifo-depth/snps,rx-fifo-depth DT properties from
>   the new binding; FIFO depth is now tied to the compatible string via
>   driver match data instead. (Conor Dooley)
> - Link to v3: https://lore.kernel.org/all/20260925-tda54-upstream-i2c-v3-1-544d74e992ff@ti.com/
> 
> Changes in v2:
> - Rename snps,dwc-i2c to ti,tda54-i2c
> - Link to v1: https://lore.kernel.org/r/20260919-tda54-upstream-i2c-v1-1-b0b9f77be18b@ti.com/
> ---
>  .../devicetree/bindings/i2c/snps,dwc-adv-i2c.yaml  | 75 ++++++++++++++++++++++
>  1 file changed, 75 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/i2c/snps,dwc-adv-i2c.yaml b/Documentation/devicetree/bindings/i2c/snps,dwc-adv-i2c.yaml
> new file mode 100644
> index 000000000000..7ad22536825e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/i2c/snps,dwc-adv-i2c.yaml
> @@ -0,0 +1,75 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/i2c/snps,dwc-adv-i2c.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Synopsys DesignWare Advanced I2C (DWC_i2c) Controller
> +
> +maintainers:
> +  - Aniket Limaye <a-limaye@ti.com>
> +
> +allOf:
> +  - $ref: /schemas/i2c/i2c-controller.yaml#
> +
> +properties:
> +  compatible:
> +    enum:
> +      - ti,tda54-i2c
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  clocks:
> +    items:
> +      - description: I2C functional clock (ic_clk)
> +      - description: Register interface clock (pclk)
> +
> +  clock-names:
> +    items:
> +      - const: ref
> +      - const: pclk
> +
> +  resets:
> +    maxItems: 1
> +
> +  clock-frequency:
> +    enum: [100000, 400000, 1000000, 3400000]
> +    default: 400000
> +
> +  i2c-sda-hold-time-ns: true

Missing  default, constraints (minimum/maximum)


> +
> +  i2c-scl-falling-time-ns:
> +    default: 300

no min/max?

> +
> +  i2c-sda-falling-time-ns:
> +    default: 300

Best regards,
Krzysztof