Re: [PATCH v6 2/3] dt-bindings: input: Add TouchNetix axiom touchscreen

[Krzysztof Kozlowski]

On 31/01/2024 10:06, Kamel Bouhara wrote:
> Hello,
> 
> On Wed, Jan 31, 2024 at 08:28:43AM +0100, Krzysztof Kozlowski wrote:
>> On 30/01/2024 23:28, Rob Herring wrote:
>>> On Fri, Jan 26, 2024 at 12:46:16PM +0100, Krzysztof Kozlowski wrote:
>>>> On 25/01/2024 17:58, Kamel Bouhara wrote:
>>>>> +  reset-gpios:
>>>>> +    maxItems: 1
>>>>> +
>>>>> +  vdda-supply:
>>>>> +    description: Analog power supply regulator on VDDA pin
>>>>> +
>>>>> +  vddi-supply:
>>>>> +    description: I/O power supply regulator on VDDI pin
>>>>> +
>>>>> +  startup-time-ms:
>>>>> +    description: delay after power supply regulator is applied in ms
>>>>
>>>> That's a regulator property - ramp up time.
>>>
>>> I'm sure there's an existing property name that could be used.
>>>
>>> But why is it needed? Is it variable per board with the same device? If
>>> not, it should be implied by the compatible.
>>
>> I meant, that regulators have such property. Unless this is coming from
>> the device needs, not from the regulator?
>>
> 
> After looking again into the device's datasheet [1], the delay (startup
> time) is not really optional and it shouldn't be set through devicetree.
> 
> IIUC, it have to be set unconditionally after a device reset or
> a vdda assertion.
> 
> [1]: https://www.touchnetix.com/media/dgnjohor/tnxd00394-a3-axiom_ax54a_2d_touch_controller_datasheet.pdf
> --

OK, then it's not a regulator ramp up, but rather part of device driver
(deduced from compatible).

Best regards,
Krzysztof