net: ethernet: mediatek: add EEE support

Add EEE support to MediaTek SoC Ethernet. The register fields are
similar to the ones in MT7531, except that the LPI threshold is in
milliseconds.

Signed-off-by: Qingfang Deng <dqfext@gmail.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/20250217094022.1065436-1-dqfext@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/mediatek/mtk_eth_soc.c

@@ -815,12 +815,60 @@ static void mtk_mac_link_up(struct phylink_config *config,
 	mtk_w32(mac->hw, mcr, MTK_MAC_MCR(mac->id));
 }
 
+static void mtk_mac_disable_tx_lpi(struct phylink_config *config)
+{
+	struct mtk_mac *mac = container_of(config, struct mtk_mac,
+					   phylink_config);
+	struct mtk_eth *eth = mac->hw;
+
+	mtk_m32(eth, MAC_MCR_EEE100M | MAC_MCR_EEE1G, 0, MTK_MAC_MCR(mac->id));
+}
+
+static int mtk_mac_enable_tx_lpi(struct phylink_config *config, u32 timer,
+				 bool tx_clk_stop)
+{
+	struct mtk_mac *mac = container_of(config, struct mtk_mac,
+					   phylink_config);
+	struct mtk_eth *eth = mac->hw;
+	u32 val;
+
+	/* Tx idle timer in ms */
+	timer = DIV_ROUND_UP(timer, 1000);
+
+	/* If the timer is zero, then set LPI_MODE, which allows the
+	 * system to enter LPI mode immediately rather than waiting for
+	 * the LPI threshold.
+	 */
+	if (!timer)
+		val = MAC_EEE_LPI_MODE;
+	else if (FIELD_FIT(MAC_EEE_LPI_TXIDLE_THD, timer))
+		val = FIELD_PREP(MAC_EEE_LPI_TXIDLE_THD, timer);
+	else
+		val = MAC_EEE_LPI_TXIDLE_THD;
+
+	if (tx_clk_stop)
+		val |= MAC_EEE_CKG_TXIDLE;
+
+	/* PHY Wake-up time, this field does not have a reset value, so use the
+	 * reset value from MT7531 (36us for 100M and 17us for 1000M).
+	 */
+	val |= FIELD_PREP(MAC_EEE_WAKEUP_TIME_1000, 17) |
+	       FIELD_PREP(MAC_EEE_WAKEUP_TIME_100, 36);
+
+	mtk_w32(eth, val, MTK_MAC_EEECR(mac->id));
+	mtk_m32(eth, 0, MAC_MCR_EEE100M | MAC_MCR_EEE1G, MTK_MAC_MCR(mac->id));
+
+	return 0;
+}
+
 static const struct phylink_mac_ops mtk_phylink_ops = {
 	.mac_select_pcs = mtk_mac_select_pcs,
 	.mac_config = mtk_mac_config,
 	.mac_finish = mtk_mac_finish,
 	.mac_link_down = mtk_mac_link_down,
 	.mac_link_up = mtk_mac_link_up,
+	.mac_disable_tx_lpi = mtk_mac_disable_tx_lpi,
+	.mac_enable_tx_lpi = mtk_mac_enable_tx_lpi,
 };
 
 static int mtk_mdio_init(struct mtk_eth *eth)
@@ -4469,6 +4517,20 @@ static int mtk_set_pauseparam(struct net_device *dev, struct ethtool_pauseparam
 	return phylink_ethtool_set_pauseparam(mac->phylink, pause);
 }
 
+static int mtk_get_eee(struct net_device *dev, struct ethtool_keee *eee)
+{
+	struct mtk_mac *mac = netdev_priv(dev);
+
+	return phylink_ethtool_get_eee(mac->phylink, eee);
+}
+
+static int mtk_set_eee(struct net_device *dev, struct ethtool_keee *eee)
+{
+	struct mtk_mac *mac = netdev_priv(dev);
+
+	return phylink_ethtool_set_eee(mac->phylink, eee);
+}
+
 static u16 mtk_select_queue(struct net_device *dev, struct sk_buff *skb,
 			    struct net_device *sb_dev)
 {
@@ -4501,6 +4563,8 @@ static const struct ethtool_ops mtk_ethtool_ops = {
 	.set_pauseparam		= mtk_set_pauseparam,
 	.get_rxnfc		= mtk_get_rxnfc,
 	.set_rxnfc		= mtk_set_rxnfc,
+	.get_eee		= mtk_get_eee,
+	.set_eee		= mtk_set_eee,
 };
 
 static const struct net_device_ops mtk_netdev_ops = {
@@ -4610,6 +4674,9 @@ static int mtk_add_mac(struct mtk_eth *eth, struct device_node *np)
 	mac->phylink_config.type = PHYLINK_NETDEV;
 	mac->phylink_config.mac_capabilities = MAC_ASYM_PAUSE | MAC_SYM_PAUSE |
 		MAC_10 | MAC_100 | MAC_1000 | MAC_2500FD;
+	mac->phylink_config.lpi_capabilities = MAC_100FD | MAC_1000FD |
+		MAC_2500FD;
+	mac->phylink_config.lpi_timer_default = 1000;
 
 	/* MT7623 gmac0 is now missing its speed-specific PLL configuration
 	 * in its .mac_config method (since state->speed is not valid there.

drivers/net/ethernet/mediatek/mtk_eth_soc.h

@@ -453,6 +453,8 @@
 #define MAC_MCR_RX_FIFO_CLR_DIS	BIT(12)
 #define MAC_MCR_BACKOFF_EN	BIT(9)
 #define MAC_MCR_BACKPR_EN	BIT(8)
+#define MAC_MCR_EEE1G		BIT(7)
+#define MAC_MCR_EEE100M		BIT(6)
 #define MAC_MCR_FORCE_RX_FC	BIT(5)
 #define MAC_MCR_FORCE_TX_FC	BIT(4)
 #define MAC_MCR_SPEED_1000	BIT(3)
@@ -461,6 +463,15 @@
 #define MAC_MCR_FORCE_LINK	BIT(0)
 #define MAC_MCR_FORCE_LINK_DOWN	(MAC_MCR_FORCE_MODE)
 
+/* Mac EEE control registers */
+#define MTK_MAC_EEECR(x)		(0x10104 + (x * 0x100))
+#define MAC_EEE_WAKEUP_TIME_1000	GENMASK(31, 24)
+#define MAC_EEE_WAKEUP_TIME_100		GENMASK(23, 16)
+#define MAC_EEE_LPI_TXIDLE_THD		GENMASK(15, 8)
+#define MAC_EEE_CKG_TXIDLE		BIT(3)
+#define MAC_EEE_CKG_RXLPI		BIT(2)
+#define MAC_EEE_LPI_MODE		BIT(0)
+
 /* Mac status registers */
 #define MTK_MAC_MSR(x)		(0x10108 + (x * 0x100))
 #define MAC_MSR_EEE1G		BIT(7)