net: mvneta: convert to phylink EEE implementation

Convert mvneta to use phylink's EEE implementation by implementing the
two LPI control methods, and adding the initial configuration and
capabilities.

Although disabling LPI requires clearing a single bit, for safety we
clear the manual mode and force bits to ensure that auto mode will be
used.

Enabling LPI needs a full configuration of several values, as the timer
values are dependent on the MAC operating speed, as per the original
code.

As Armada 388 states that EEE is only supported in "SGMII" modes, mark
this in lpi_interfaces. Testing with RGMII on the Clearfog platform
indicates that the receive path fails to detect LPI over RGMII.

Signed-off-by: Russell King (Oracle) <[email protected]>
Reviewed-by: Jacob Keller <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: Russell King (Oracle)

drivers/net/ethernet/marvell/mvneta.c

@@ -284,8 +284,12 @@
 					  MVNETA_TXQ_BUCKET_REFILL_PERIOD))
 
 #define MVNETA_LPI_CTRL_0                        0x2cc0
+#define      MVNETA_LPI_CTRL_0_TS                (0xff << 8)
 #define MVNETA_LPI_CTRL_1                        0x2cc4
-#define      MVNETA_LPI_REQUEST_ENABLE           BIT(0)
+#define      MVNETA_LPI_CTRL_1_REQUEST_ENABLE    BIT(0)
+#define      MVNETA_LPI_CTRL_1_REQUEST_FORCE     BIT(1)
+#define      MVNETA_LPI_CTRL_1_MANUAL_MODE       BIT(2)
+#define      MVNETA_LPI_CTRL_1_TW                (0xfff << 4)
 #define MVNETA_LPI_CTRL_2                        0x2cc8
 #define MVNETA_LPI_STATUS                        0x2ccc
 
@@ -541,10 +545,6 @@ struct mvneta_port {
 	struct mvneta_bm_pool *pool_short;
 	int bm_win_id;
 
-	bool eee_enabled;
-	bool eee_active;
-	bool tx_lpi_enabled;
-
 	u64 ethtool_stats[ARRAY_SIZE(mvneta_statistics)];
 
 	u32 indir[MVNETA_RSS_LU_TABLE_SIZE];
@@ -4213,18 +4213,6 @@ static int mvneta_mac_finish(struct phylink_config *config, unsigned int mode,
 	return 0;
 }
 
-static void mvneta_set_eee(struct mvneta_port *pp, bool enable)
-{
-	u32 lpi_ctl1;
-
-	lpi_ctl1 = mvreg_read(pp, MVNETA_LPI_CTRL_1);
-	if (enable)
-		lpi_ctl1 |= MVNETA_LPI_REQUEST_ENABLE;
-	else
-		lpi_ctl1 &= ~MVNETA_LPI_REQUEST_ENABLE;
-	mvreg_write(pp, MVNETA_LPI_CTRL_1, lpi_ctl1);
-}
-
 static void mvneta_mac_link_down(struct phylink_config *config,
 				 unsigned int mode, phy_interface_t interface)
 {
@@ -4240,9 +4228,6 @@ static void mvneta_mac_link_down(struct phylink_config *config,
 		val |= MVNETA_GMAC_FORCE_LINK_DOWN;
 		mvreg_write(pp, MVNETA_GMAC_AUTONEG_CONFIG, val);
 	}
-
-	pp->eee_active = false;
-	mvneta_set_eee(pp, false);
 }
 
 static void mvneta_mac_link_up(struct phylink_config *config,
@@ -4291,11 +4276,56 @@ static void mvneta_mac_link_up(struct phylink_config *config,
 	}
 
 	mvneta_port_up(pp);
+}
 
-	if (phy && pp->eee_enabled) {
-		pp->eee_active = phy_init_eee(phy, false) >= 0;
-		mvneta_set_eee(pp, pp->eee_active && pp->tx_lpi_enabled);
+static void mvneta_mac_disable_tx_lpi(struct phylink_config *config)
+{
+	struct mvneta_port *pp = netdev_priv(to_net_dev(config->dev));
+	u32 lpi1;
+
+	lpi1 = mvreg_read(pp, MVNETA_LPI_CTRL_1);
+	lpi1 &= ~(MVNETA_LPI_CTRL_1_REQUEST_ENABLE |
+		  MVNETA_LPI_CTRL_1_REQUEST_FORCE |
+		  MVNETA_LPI_CTRL_1_MANUAL_MODE);
+	mvreg_write(pp, MVNETA_LPI_CTRL_1, lpi1);
+}
+
+static int mvneta_mac_enable_tx_lpi(struct phylink_config *config, u32 timer,
+				    bool tx_clk_stop)
+{
+	struct mvneta_port *pp = netdev_priv(to_net_dev(config->dev));
+	u32 ts, tw, lpi0, lpi1, status;
+
+	status = mvreg_read(pp, MVNETA_GMAC_STATUS);
+	if (status & MVNETA_GMAC_SPEED_1000) {
+		/* At 1G speeds, the timer resolution are 1us, and
+		 * 802.3 says tw is 16.5us. Round up to 17us.
+		 */
+		tw = 17;
+		ts = timer;
+	} else {
+		/* At 100M speeds, the timer resolutions are 10us, and
+		 * 802.3 says tw is 30us.
+		 */
+		tw = 3;
+		ts = DIV_ROUND_UP(timer, 10);
 	}
+
+	if (ts > 255)
+		ts = 255;
+
+	/* Configure ts */
+	lpi0 = mvreg_read(pp, MVNETA_LPI_CTRL_0);
+	lpi0 = u32_replace_bits(lpi0, ts, MVNETA_LPI_CTRL_0_TS);
+	mvreg_write(pp, MVNETA_LPI_CTRL_0, lpi0);
+
+	/* Configure tw and enable LPI generation */
+	lpi1 = mvreg_read(pp, MVNETA_LPI_CTRL_1);
+	lpi1 = u32_replace_bits(lpi1, tw, MVNETA_LPI_CTRL_1_TW);
+	lpi1 |= MVNETA_LPI_CTRL_1_REQUEST_ENABLE;
+	mvreg_write(pp, MVNETA_LPI_CTRL_1, lpi1);
+
+	return 0;
 }
 
 static const struct phylink_mac_ops mvneta_phylink_ops = {
@@ -4305,6 +4335,8 @@ static const struct phylink_mac_ops mvneta_phylink_ops = {
 	.mac_finish = mvneta_mac_finish,
 	.mac_link_down = mvneta_mac_link_down,
 	.mac_link_up = mvneta_mac_link_up,
+	.mac_disable_tx_lpi = mvneta_mac_disable_tx_lpi,
+	.mac_enable_tx_lpi = mvneta_mac_enable_tx_lpi,
 };
 
 static int mvneta_mdio_probe(struct mvneta_port *pp)
@@ -5109,14 +5141,6 @@ static int mvneta_ethtool_get_eee(struct net_device *dev,
 				  struct ethtool_keee *eee)
 {
 	struct mvneta_port *pp = netdev_priv(dev);
-	u32 lpi_ctl0;
-
-	lpi_ctl0 = mvreg_read(pp, MVNETA_LPI_CTRL_0);
-
-	eee->eee_enabled = pp->eee_enabled;
-	eee->eee_active = pp->eee_active;
-	eee->tx_lpi_enabled = pp->tx_lpi_enabled;
-	eee->tx_lpi_timer = (lpi_ctl0) >> 8; // * scale;
 
 	return phylink_ethtool_get_eee(pp->phylink, eee);
 }
@@ -5125,24 +5149,13 @@ static int mvneta_ethtool_set_eee(struct net_device *dev,
 				  struct ethtool_keee *eee)
 {
 	struct mvneta_port *pp = netdev_priv(dev);
-	u32 lpi_ctl0;
 
 	/* The Armada 37x documents do not give limits for this other than
 	 * it being an 8-bit register.
 	 */
 	if (eee->tx_lpi_enabled && eee->tx_lpi_timer > 255)
 		return -EINVAL;
 
-	lpi_ctl0 = mvreg_read(pp, MVNETA_LPI_CTRL_0);
-	lpi_ctl0 &= ~(0xff << 8);
-	lpi_ctl0 |= eee->tx_lpi_timer << 8;
-	mvreg_write(pp, MVNETA_LPI_CTRL_0, lpi_ctl0);
-
-	pp->eee_enabled = eee->eee_enabled;
-	pp->tx_lpi_enabled = eee->tx_lpi_enabled;
-
-	mvneta_set_eee(pp, eee->tx_lpi_enabled && eee->eee_enabled);
-
 	return phylink_ethtool_set_eee(pp->phylink, eee);
 }
 
@@ -5456,6 +5469,9 @@ static int mvneta_port_power_up(struct mvneta_port *pp, int phy_mode)
 	    !phy_interface_mode_is_rgmii(phy_mode))
 		return -EINVAL;
 
+	/* Ensure LPI is disabled */
+	mvneta_mac_disable_tx_lpi(&pp->phylink_config);
+
 	return 0;
 }
 
@@ -5547,6 +5563,13 @@ static int mvneta_probe(struct platform_device *pdev)
 	pp->phylink_config.mac_capabilities = MAC_SYM_PAUSE | MAC_10 |
 		MAC_100 | MAC_1000FD | MAC_2500FD;
 
+	/* Setup EEE. Choose 250us idle. Only supported in SGMII modes. */
+	__set_bit(PHY_INTERFACE_MODE_QSGMII, pp->phylink_config.lpi_interfaces);
+	__set_bit(PHY_INTERFACE_MODE_SGMII, pp->phylink_config.lpi_interfaces);
+	pp->phylink_config.lpi_capabilities = MAC_100FD | MAC_1000FD;
+	pp->phylink_config.lpi_timer_default = 250;
+	pp->phylink_config.eee_enabled_default = true;
+
 	phy_interface_set_rgmii(pp->phylink_config.supported_interfaces);
 	__set_bit(PHY_INTERFACE_MODE_QSGMII,
 		  pp->phylink_config.supported_interfaces);