Re: [PATCH v3 1/2] dt-bindings: media: i2c: Add Samsung S5KJN1 image sensor

[Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>]

Hi Luca!

On 11/4/25 12:20, Luca Weiss wrote:
> Hi Vladimir,
> 
> On Thu Oct 23, 2025 at 4:53 AM CEST, Vladimir Zapolskiy wrote:
>> Add device tree bindings documentation for Samsung S5KJN1 image sensor.
> 
> Awesome that you're working on upstreaming support for this sensor!
> 
> This sensor is used for the front camera on the Fairphone 5 so I'll give
> it a try sometime soon. So far I've been using my own version of the
> driver in my tree.
> 

I haven't seen it, for the initialization sequence I used Android drivers
from github.

> Some comments below.
> 
>>
>> Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
>> Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
>> ---
>>   .../bindings/media/i2c/samsung,s5kjn1.yaml    | 103 ++++++++++++++++++
>>   1 file changed, 103 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/media/i2c/samsung,s5kjn1.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/media/i2c/samsung,s5kjn1.yaml b/Documentation/devicetree/bindings/media/i2c/samsung,s5kjn1.yaml
>> new file mode 100644
>> index 000000000000..f0cc0209b5f0
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/media/i2c/samsung,s5kjn1.yaml
>> @@ -0,0 +1,103 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/media/i2c/samsung,s5kjn1.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Samsung S5KJN1 Image Sensor
>> +
>> +description:
>> +  Samsung S5KJN1 (ISOCELL JN1) image sensor is a 50MP image sensor.
>> +  The sensor is controlled over a serial camera control bus protocol,
>> +  the widest supported output image frame size is 8160x6144 at 10 frames
>> +  per second rate, data output format is RAW10 transferred over 4-lane
>> +  MIPI D-PHY interface.
>> +
>> +maintainers:
>> +  - Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
>> +
>> +allOf:
>> +  - $ref: /schemas/media/video-interface-devices.yaml#
>> +
>> +properties:
>> +  compatible:
>> +    const: samsung,s5kjn1
>> +
>> +  reg:
>> +    maxItems: 1
>> +
>> +  clocks:
>> +    description: MCLK supply clock.
>> +    maxItems: 1
>> +
>> +  reset-gpios:
>> +    description: Active low GPIO connected to RESET pad of the sensor.
>> +    maxItems: 1
>> +
>> +  afvdd-supply:
>> +    description: Autofocus voltage supply, 2.8-3.0 volts.
> 
> This is not part of the S5KJN1 though? If you have a VCM for the lens of
> the S5KJN1, this is a separate DT node?
> 

Autofocus supply is not in the list of sensor IC supplies, however
1) this is a supply line of sensor modules,
2) a sensor could have controls its controls over autofocus,

so, a VCM for the lens is the sensor.

Some time ago I discussed this particular question on the #linux-media in
connection to another Samsung and Omnivision sensors, and I got a response
that it's favourable to add an autofocus regulator control under a sensor
device tree node.

>> +
>> +  avdd-supply:
>> +    description: Analogue voltage supply, 2.8 volts.
> 
> The datasheet calls this VDDA
> 

I don't have a datasheet, and it should be updated accordingly, thank you.

>> +
>> +  dovdd-supply:
>> +    description: Digital I/O voltage supply, 1.8 volts.
> 
> The datasheet calls this VDDIO
> 

Same as above.

>> +
>> +  dvdd-supply:
>> +    description: Digital core voltage supply, 1.05 volts.
> 
> The datasheet calls this VDDD
> 

Same as above, thank you so much!

-- 
Best wishes,
Vladimir