net: dpaa2-mac: add backplane link mode support

Add support for backplane link mode, which is, according to discussions
with NXP earlier in the year, is a mode where the OS (Linux) is able to
manage the PCS and Serdes itself.

This commit prepares the ground work for allowing 1G fiber connections
to be used with DPAA2 on the SolidRun CEX7 platforms.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h

@@ -695,7 +695,9 @@ static inline unsigned int dpaa2_eth_rx_head_room(struct dpaa2_eth_priv *priv)
 
 static inline bool dpaa2_eth_is_type_phy(struct dpaa2_eth_priv *priv)
 {
-	if (priv->mac && priv->mac->attr.link_type == DPMAC_LINK_TYPE_PHY)
+	if (priv->mac &&
+	    (priv->mac->attr.link_type == DPMAC_LINK_TYPE_PHY ||
+	     priv->mac->attr.link_type == DPMAC_LINK_TYPE_BACKPLANE))
 		return true;
 
 	return false;

drivers/net/ethernet/freescale/dpaa2/dpaa2-mac.c

@@ -315,8 +315,9 @@ int dpaa2_mac_connect(struct dpaa2_mac *mac)
 		goto err_put_node;
 	}
 
-	if (mac->attr.link_type == DPMAC_LINK_TYPE_PHY &&
-	    mac->attr.eth_if != DPMAC_ETH_IF_RGMII) {
+	if ((mac->attr.link_type == DPMAC_LINK_TYPE_PHY &&
+	     mac->attr.eth_if != DPMAC_ETH_IF_RGMII) ||
+	    mac->attr.link_type == DPMAC_LINK_TYPE_BACKPLANE) {
 		err = dpaa2_pcs_create(mac, dpmac_node, mac->attr.id);
 		if (err)
 			goto err_put_node;