Subject: [PATCH RFC net-next 12/23] net: mvneta: convert to phylink EEE implementation

From: "Russell King (Oracle)" <[email-masked]>
Date: Tue, 26 Nov 2024 12:53:12 +0000

Convert mvneta to use phylink's EEE implementation, which means we just
need to implement the two methods for LPI control, and adding the
initial configuration.

Disabling LPI requires clearing a single bit. Enabling LPI needs a full
configuration of several values, as the timer values are dependent on
the MAC operating speed.

Signed-off-by: Russell King (Oracle) <[email-masked]>
---
 drivers/net/ethernet/marvell/mvneta.c | 116 +++++++++++++++-----------
 1 file changed, 68 insertions(+), 48 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 1fb285fa0bdb..976ce8d6dabf 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/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];
@@ -1354,6 +1354,13 @@ static void mvneta_port_enable(struct mvneta_port *pp)
 	val = mvreg_read(pp, MVNETA_GMAC_CTRL_0);
 	val |= MVNETA_GMAC0_PORT_ENABLE;
 	mvreg_write(pp, MVNETA_GMAC_CTRL_0, val);
+
+	/* Ensure LPI is disabled */
+	val = mvreg_read(pp, MVNETA_LPI_CTRL_1);
+	val &= ~(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, val);
 }
 
 /* Disable the port and wait for about 200 usec before retuning */
@@ -4206,18 +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)
 {
@@ -4233,9 +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,
@@ -4284,11 +4276,53 @@ static void mvneta_mac_link_up(struct phylink_config *config,
 	}
 
 	mvneta_port_up(pp);
+}
+
+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;
+	mvreg_write(pp, MVNETA_LPI_CTRL_1, lpi1);
+}
+
+static void 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;
 
-	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);
+	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, MVNETA_LPI_CTRL_0_TS, 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, MVNETA_LPI_CTRL_1_TW, tw);
+	lpi1 |= MVNETA_LPI_CTRL_1_REQUEST_ENABLE;
+	mvreg_write(pp, MVNETA_LPI_CTRL_1, lpi1);
 }
 
 static const struct phylink_mac_ops mvneta_phylink_ops = {
@@ -4298,6 +4332,8 @@ 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)
@@ -5099,14 +5135,6 @@ 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);
 }
@@ -5115,23 +5143,6 @@ 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);
 }
@@ -5446,6 +5457,9 @@ 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;
 }
 
@@ -5537,6 +5551,12 @@ 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. */
+	pp->phylink_config.lpi_capabilities = MAC_100FD | MAC_1000FD;
+	pp->phylink_config.lpi_timer_limit_us = 255;
+	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);
-- 
2.30.2