On Mon, Jun 06, 2022 at 10:22:18PM +0200, Rasmus Villemoes wrote:
> We have a board where measurements indicate that the current three
> options - leaving IO_IMPEDANCE_CTRL at the (factory calibrated) reset
> value or using one of the two boolean properties to set it to the
> min/max value - are too coarse.
>
> There is no documented mapping from the 32 possible values of the
> IO_IMPEDANCE_CTRL field to values in the range 35-70 ohms, and the
> exact mapping is likely to vary from chip to chip. So add a DT binding
> for an nvmem cell which can be populated during production with a
> value suitable for each specific board.
>
> Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
Andrew
