Re: [PATCH v3 2/3] dt-bindings: serial: maxim,max310x: describe per-channel rs485 subnodes

[Rob Herring (Arm)]

On Mon, 15 Jun 2026 10:27:36 +0000, Tapio Reijonen wrote:
> The MAX310x is a family of one- (max3107, max3108), two- (max3109) and
> four-channel (max14830) UARTs. The binding pulls in
> /schemas/serial/rs485.yaml at the chip level, describing a single set of
> RS-485 properties - enough for the single-channel parts, but a
> multi-channel chip can wire RS-485 differently on each channel.
> 
> Split the binding per compatible:
> 
>  - single-channel parts (max3107, max3108): the chip node is itself the
>    serial port and carries the RS-485 properties, as before;
> 
>  - multi-channel parts (max3109, max14830): the chip node is only a
>    container and is no longer a serial node; each channel is a "serial@N"
>    subnode that carries the standard serial.yaml/rs485.yaml properties
>    (and may host a serial slave device). max3109 has channels 0-1,
>    max14830 has 0-3.
> 
> This avoids a chip node that is simultaneously a serial node and the
> parent of serial nodes. The driver still reads chip-level RS-485 for
> single-channel and legacy device trees, so existing users are unaffected.
> 
> Signed-off-by: Tapio Reijonen <tapio.reijonen@xxxxxxxxxxx>
> ---
>  .../devicetree/bindings/serial/maxim,max310x.yaml  | 92 +++++++++++++++++++++-
>  1 file changed, 90 insertions(+), 2 deletions(-)
> 

Reviewed-by: Rob Herring (Arm) <robh@xxxxxxxxxx>