[PATCH 4/5] net: cadence: macb: add ethtool EEE support

[Nicolai Buchwitz <nb@tipi-net.de>]

Implement ethtool get_eee and set_eee operations for the Cadence GEM
MAC, delegating to phylink for PHY-level EEE negotiation state.

The MAC-level LPI control (TXLPIEN) is not manipulated directly in the
ethtool ops - phylink manages the full EEE lifecycle through the
mac_enable_tx_lpi / mac_disable_tx_lpi callbacks.

Both ops are gated on MACB_CAPS_EEE; platforms without the capability
flag return -EOPNOTSUPP.

Signed-off-by: Nicolai Buchwitz <nb@tipi-net.de>
---
 drivers/net/ethernet/cadence/macb_main.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index a9ae7ecf9fe9..37a5b866e3a5 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -4033,6 +4033,26 @@ static const struct ethtool_ops macb_ethtool_ops = {
 	.set_ringparam		= macb_set_ringparam,
 };
 
+static int macb_get_eee(struct net_device *dev, struct ethtool_keee *eee)
+{
+	struct macb *bp = netdev_priv(dev);
+
+	if (!(bp->caps & MACB_CAPS_EEE))
+		return -EOPNOTSUPP;
+
+	return phylink_ethtool_get_eee(bp->phylink, eee);
+}
+
+static int macb_set_eee(struct net_device *dev, struct ethtool_keee *eee)
+{
+	struct macb *bp = netdev_priv(dev);
+
+	if (!(bp->caps & MACB_CAPS_EEE))
+		return -EOPNOTSUPP;
+
+	return phylink_ethtool_set_eee(bp->phylink, eee);
+}
+
 static const struct ethtool_ops gem_ethtool_ops = {
 	.get_regs_len		= macb_get_regs_len,
 	.get_regs		= macb_get_regs,
@@ -4054,6 +4074,8 @@ static const struct ethtool_ops gem_ethtool_ops = {
 	.get_rxnfc			= gem_get_rxnfc,
 	.set_rxnfc			= gem_set_rxnfc,
 	.get_rx_ring_count		= gem_get_rx_ring_count,
+	.get_eee		= macb_get_eee,
+	.set_eee		= macb_set_eee,
 };
 
 static int macb_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
-- 
2.51.0