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

[Aniket Limaye]

On 28/10/26 00:06, Krzysztof Kozlowski wrote:
> 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@xxxxxx>
> >
> > ---
>
> Here you mention dependency on new dtschema (unreleased), since the
> property was added a few days ago.

Ahh okay, will add in next version

> > 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@xxxxxx/
> >
> > 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@xxxxxx/
> > ---
> >   .../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@xxxxxx>
> > +
> > +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?

Ack, will add those defaults and constraints in next version.

> > +
> > +  i2c-sda-falling-time-ns:
> > +    default: 300
>
> Best regards,
> Krzysztof

Thanks for the review!
Aniket