net: ethernet: cortina: Implement .set_pauseparam()

The Cortina Gemini ethernet can very well set up TX or RX
pausing, so add this functionality to the driver in a
.set_pauseparam() callback. Essentially just call down to
phylib and let phylib deal with this, .adjust_link()
will respect the setting from phylib.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20240529-gemini-phylib-fixes-v4-3-16487ca4c2fe@linaro.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/cortina/gemini.c

@@ -2126,6 +2126,19 @@ static void gmac_get_pauseparam(struct net_device *netdev,
 	pparam->autoneg = true;
 }
 
+static int gmac_set_pauseparam(struct net_device *netdev,
+			       struct ethtool_pauseparam *pparam)
+{
+	struct phy_device *phydev = netdev->phydev;
+
+	if (!pparam->autoneg)
+		return -EOPNOTSUPP;
+
+	phy_set_asym_pause(phydev, pparam->rx_pause, pparam->tx_pause);
+
+	return 0;
+}
+
 static void gmac_get_ringparam(struct net_device *netdev,
 			       struct ethtool_ringparam *rp,
 			       struct kernel_ethtool_ringparam *kernel_rp,
@@ -2246,6 +2259,7 @@ static const struct ethtool_ops gmac_351x_ethtool_ops = {
 	.set_link_ksettings = gmac_set_ksettings,
 	.nway_reset	= gmac_nway_reset,
 	.get_pauseparam	= gmac_get_pauseparam,
+	.set_pauseparam = gmac_set_pauseparam,
 	.get_ringparam	= gmac_get_ringparam,
 	.set_ringparam	= gmac_set_ringparam,
 	.get_coalesce	= gmac_get_coalesce,