[PATCH v2 1/6] dt-bindings: clock: imx8m: document nominal/overdrive properties

[Krzysztof Kozlowski]

On Mon, Jan 06, 2025 at 08:55:08PM +0100, Ahmad Fatoum wrote:
> >>> why need two flags? suppose "not set fsl,overdrive-mode" is equal to
> >>> fsl,nominal-mode
> >>
> >> Conor had the same question on v1[1] and I have addressed this in the commit
> >> message of v2, see above.
> >>
> >> In short, there is unfortunately no universally applicable default.
> >>
> >> [1]: https://lore.kernel.org/all/4e2250b3-5170-4e88-aa0a-dd796b81e78b@pengutronix.de/
> >>
> > 
> > But there are problem if use dts overlay because dts overlay can't support
> > delete property.
> > 
> > If one dts file use "fsl,overdrive-mode", dts overlay file can't delete
> > this property. "mutually exclusive optional properties" was not preferred.
> > 
> > mode = ["normal" | "overdrive"]
> 
> I don't see myself setting this via overlay, but if you say it's useful, we can
> adjust the binding.
> 
> I am not sure what's the preference is though, should we have
> 
>   fsl,operating-mode = "normal" / "overdrive"
> 
> or 
> 
>   fsl,operating-mode = <IMX_OPMODE_NORMAL> / <IMX_OPMODE_OVERDRIVE>
> 
> 
> Any idea? Conor?

If these are two exclusive modes (plus default), then as Frank
suggested: use enum of strings. Imagine encoding enum of 10 values with
bools as you did: that would be enourmous oneOf condition or if:then:.

Preferred is strings, but numerical values are also accepted.

Best regards,
Krzysztof