[PATCH v9 4/8] net: dsa: allow rcv() and xmit() to be optional

[Tim Harvey <tharvey@gateworks.com>]

Allow rcv() and xmit() dsa driver ops to be optional in case a driver
does not care to mangle a packet as in U-Boot only one network port is
enabled at a time and thus no packet mangling is necessary.

Suggested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Fabio Estevam <festevam@denx.de>
Signed-off-by: Tim Harvey <tharvey@gateworks.com>
---
v9:
 - fixed dsa_port_send when xmit function is defined
v8:
 - no changes
v7:
 - no changes
v6:
 - no changes
v5:
 - added Fabio's rb tag
v4:
 - no changes
v3:
 - added Vladimir's rb tag
v2: new patch
---
 net/dsa-uclass.c | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/net/dsa-uclass.c b/net/dsa-uclass.c
index 211a991cdd0d..dd78e5744d58 100644
--- a/net/dsa-uclass.c
+++ b/net/dsa-uclass.c
@@ -142,20 +142,22 @@ static int dsa_port_send(struct udevice *pdev, void *packet, int length)
 	struct dsa_port_pdata *port_pdata;
 	int err;
 
-	if (length + head + tail > PKTSIZE_ALIGN)
-		return -EINVAL;
+	if (ops->xmit) {
+		if (length + head + tail > PKTSIZE_ALIGN)
+			return -EINVAL;
 
-	memset(dsa_packet_tmp, 0, head);
-	memset(dsa_packet_tmp + head + length, 0, tail);
-	memcpy(dsa_packet_tmp + head, packet, length);
-	length += head + tail;
-	/* copy back to preserve original buffer alignment */
-	memcpy(packet, dsa_packet_tmp, length);
+		memset(dsa_packet_tmp, 0, head);
+		memset(dsa_packet_tmp + head + length, 0, tail);
+		memcpy(dsa_packet_tmp + head, packet, length);
+		length += head + tail;
+		/* copy back to preserve original buffer alignment */
+		memcpy(packet, dsa_packet_tmp, length);
 
-	port_pdata = dev_get_parent_plat(pdev);
-	err = ops->xmit(dev, port_pdata->index, packet, length);
-	if (err)
-		return err;
+		port_pdata = dev_get_parent_plat(pdev);
+		err = ops->xmit(dev, port_pdata->index, packet, length);
+		if (err)
+			return err;
+	}
 
 	return eth_get_ops(master)->send(master, packet, length);
 }
@@ -172,7 +174,7 @@ static int dsa_port_recv(struct udevice *pdev, int flags, uchar **packetp)
 	int length, port_index, err;
 
 	length = eth_get_ops(master)->recv(master, flags, packetp);
-	if (length <= 0)
+	if (length <= 0 || !ops->rcv)
 		return length;
 
 	/*
-- 
2.25.1