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

[Aniket Limaye <a-limaye@ti.com>]

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@ti.com>
>>
>> ---
>>
> 
> 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@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?
> 

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