[PATCH net-next] net: lan969x: correct RGMII port mapping index

[Robert Marko]

Currently, the lan969x_port_dev_mapping does not check for RGMII ports
and just returns the physical port index.

However, this does not work for RGMII ports as they have dedicated DEVRGMII
register space with an dedicated instance per RGMII port.

So, check if requested port index is an RGMII port and return the correct
DEVRGMII index.

Signed-off-by: Robert Marko <robert.marko at sartura.hr>
---
 drivers/net/ethernet/microchip/sparx5/lan969x/lan969x.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/net/ethernet/microchip/sparx5/lan969x/lan969x.c b/drivers/net/ethernet/microchip/sparx5/lan969x/lan969x.c
index f3a9c71bea36a..bf5320c7a6ca8 100644
--- a/drivers/net/ethernet/microchip/sparx5/lan969x/lan969x.c
+++ b/drivers/net/ethernet/microchip/sparx5/lan969x/lan969x.c
@@ -142,6 +142,15 @@ static u32 lan969x_get_dev_mode_bit(struct sparx5 *sparx5, int port)
 
 static u32 lan969x_port_dev_mapping(struct sparx5 *sparx5, int port)
 {
+	if (lan969x_port_is_rgmii(port)) {
+		switch (port) {
+		case 28:
+			return 0;
+		case 29:
+			return 1;
+		}
+	}
+
 	if (lan969x_port_is_5g(port)) {
 		switch (port) {
 		case 9:
-- 
2.55.0