Re: [PATCH v3 1/2] dt-bindings: media: i2c: dongwoon,dw9714: Document DW9714A and V variant

[David Heidelberg <david@ixit.cz>]

On 26/08/2026 22:13, Sakari Ailus wrote:
> Hi David,
> 
> On Mon, Aug 10, 2026 at 12:24:58PM +0200, David Heidelberg wrote:
>> On 10/08/2026 11:38, Sakari Ailus wrote:
>>> Hi David,
>>>
>>> On Mon, Aug 03, 2026 at 11:50:25AM +0200, David Heidelberg via B4 Relay wrote:
>>>> From: David Heidelberg <david@ixit.cz>
>>>>
>>>> DW9714A is successor of DW9714 and DW9714V is successor of the DW9714A.
>>>>
>>>> All actuators are backward compatible, but they do introduce new features,
>>>> such as Smart Actuator Control (SAC) mode which can minimize the
>>>> mechanical vibration and achieve very fast mechanical settling time.
>>>> Support for SAC can be implemented in the future.
>>>
>>> What kind of configuration does SAC require? Such things generally aren't
>>> configured from the userspace, compare e.g. with the dw9719 bindings
>>> discussion.
>>
>> I don't have extra deep insight (except basic how the sensor works).
>>
>> By default all dw9714* sensors starts in the default "legacy" mode.
>>
>> The clanker after looking at datasheets and kernel struct produced, if it
>> make sense:
>>
>> the mode and the vibration period (SAC_CFG/PRESC/SACT) have to match
>> the mechanical tVIB of the actuator and lens assembly of the given camera
>> module, the same way dongwoon,aac-mode/aac-timing/clock-presc do for
>> dongwoon,dw9768 and dongwoon,sac-mode/vcm-prescale for dongwoon,dw9719.
>> Those properties are left out until there is driver support and measured
>> values; note the DW9714V mode set differs from DW9719's, so its enum cannot
>> be reused as is.
> 
> I guess this is fine, but without the configuration there's not much
> benefit knowing the VCM is actually a bit more sophisticated one.

Yes, definitely. I just wanted to use proper compatible from the start.

I plan to dive into it deeper when libcamera integrates the AF, as for now doing 
extra work here has not many benefits.

David