net: phy: realtek: Add tx/rx delay config for 8211e

Some boards need to change the tx/rx delay config in order for
gigabit Ethernet to work.

In Linux commit bbc4d71d6354 ("net: phy: realtek: fix rtl8211e rx/tx
delay config"), Realtek documented the bits for overriding the delays
from the hardware straps.

Copy the logic from linux, so the delay config is set from the PHY's
interface type (the phy-mode property in the device tree).

This removes the need for a one-off workaround for the Pine A64+ board.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>

2 files changed, 43 insertions, 36 deletions

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 68ee7d7a2d..e69cd8a4b3 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -214,16 +214,6 @@ config PHY_NXP_C45_TJA11XX
 config PHY_REALTEK
 	bool "Realtek Ethernet PHYs support"
 
-config RTL8211E_PINE64_GIGABIT_FIX
-	bool "Fix gigabit throughput on some Pine64+ models"
-	depends on PHY_REALTEK
-	help
-	  Configure the Realtek RTL8211E found on some Pine64+ models differently to
-	  fix throughput on Gigabit links, turning off all internal delays in the
-	  process. The settings that this touches are not documented in the CONFREG
-	  section of the RTL8211E datasheet, but come from Realtek by way of the
-	  Pine64 engineering team.
-
 config RTL8211X_PHY_FORCE_MASTER
 	bool "Ethernet PHY RTL8211x: force 1000BASE-T master mode"
 	depends on PHY_REALTEK
diff --git a/drivers/net/phy/realtek.c b/drivers/net/phy/realtek.c
index b1b1fa5080..24c3ea59bb 100644
--- a/drivers/net/phy/realtek.c
+++ b/drivers/net/phy/realtek.c
@@ -12,7 +12,6 @@
 #include <linux/delay.h>
 
 #define PHY_RTL8211x_FORCE_MASTER BIT(1)
-#define PHY_RTL8211E_PINE64_GIGABIT_FIX BIT(2)
 #define PHY_RTL8211F_FORCE_EEE_RXC_ON BIT(3)
 #define PHY_RTL8201F_S700_RMII_TIMINGS BIT(4)
 
@@ -49,10 +48,10 @@
 #define MIIM_RTL8211F_PHYSTAT_SPDDONE  0x0800
 #define MIIM_RTL8211F_PHYSTAT_LINK     0x0004
 
-#define MIIM_RTL8211E_CONFREG           0x1c
-#define MIIM_RTL8211E_CONFREG_TXD		0x0002
-#define MIIM_RTL8211E_CONFREG_RXD		0x0004
-#define MIIM_RTL8211E_CONFREG_MAGIC		0xb400	/* Undocumented */
+#define MIIM_RTL8211E_CONFREG		0x1c
+#define MIIM_RTL8211E_CTRL_DELAY	BIT(13)
+#define MIIM_RTL8211E_TX_DELAY		BIT(12)
+#define MIIM_RTL8211E_RX_DELAY		BIT(11)
 
 #define MIIM_RTL8211E_EXT_PAGE_SELECT  0x1e
 
@@ -108,10 +107,6 @@ static int rtl8211b_probe(struct phy_device *phydev)
 
 static int rtl8211e_probe(struct phy_device *phydev)
 {
-#ifdef CONFIG_RTL8211E_PINE64_GIGABIT_FIX
-	phydev->flags |= PHY_RTL8211E_PINE64_GIGABIT_FIX;
-#endif
-
 	return 0;
 }
 
@@ -154,22 +149,6 @@ static int rtl8211x_config(struct phy_device *phydev)
 		reg |= MIIM_RTL8211x_CTRL1000T_MASTER;
 		phy_write(phydev, MDIO_DEVAD_NONE, MII_CTRL1000, reg);
 	}
-	if (phydev->flags & PHY_RTL8211E_PINE64_GIGABIT_FIX) {
-		unsigned int reg;
-
-		phy_write(phydev, MDIO_DEVAD_NONE, MIIM_RTL8211F_PAGE_SELECT,
-			  7);
-		phy_write(phydev, MDIO_DEVAD_NONE,
-			  MIIM_RTL8211E_EXT_PAGE_SELECT, 0xa4);
-		reg = phy_read(phydev, MDIO_DEVAD_NONE, MIIM_RTL8211E_CONFREG);
-		/* Ensure both internal delays are turned off */
-		reg &= ~(MIIM_RTL8211E_CONFREG_TXD | MIIM_RTL8211E_CONFREG_RXD);
-		/* Flip the magic undocumented bits */
-		reg |= MIIM_RTL8211E_CONFREG_MAGIC;
-		phy_write(phydev, MDIO_DEVAD_NONE, MIIM_RTL8211E_CONFREG, reg);
-		phy_write(phydev, MDIO_DEVAD_NONE, MIIM_RTL8211F_PAGE_SELECT,
-			  0);
-	}
 	/* read interrupt status just to clear it */
 	phy_read(phydev, MDIO_DEVAD_NONE, MIIM_RTL8211x_PHY_INER);
 
@@ -201,6 +180,44 @@ static int rtl8201f_config(struct phy_device *phydev)
 	return 0;
 }
 
+static int rtl8211e_config(struct phy_device *phydev)
+{
+	int reg, val;
+
+	/* enable TX/RX delay for rgmii-* modes, and disable them for rgmii. */
+	switch (phydev->interface) {
+	case PHY_INTERFACE_MODE_RGMII:
+		val = MIIM_RTL8211E_CTRL_DELAY;
+		break;
+	case PHY_INTERFACE_MODE_RGMII_ID:
+		val = MIIM_RTL8211E_CTRL_DELAY | MIIM_RTL8211E_TX_DELAY |
+		      MIIM_RTL8211E_RX_DELAY;
+		break;
+	case PHY_INTERFACE_MODE_RGMII_RXID:
+		val = MIIM_RTL8211E_CTRL_DELAY | MIIM_RTL8211E_RX_DELAY;
+		break;
+	case PHY_INTERFACE_MODE_RGMII_TXID:
+		val = MIIM_RTL8211E_CTRL_DELAY | MIIM_RTL8211E_TX_DELAY;
+		break;
+	default: /* the rest of the modes imply leaving delays as is. */
+		goto default_delay;
+	}
+
+	phy_write(phydev, MDIO_DEVAD_NONE, MIIM_RTL8211F_PAGE_SELECT, 7);
+	phy_write(phydev, MDIO_DEVAD_NONE, MIIM_RTL8211E_EXT_PAGE_SELECT, 0xa4);
+
+	reg = phy_read(phydev, MDIO_DEVAD_NONE, MIIM_RTL8211E_CONFREG);
+	reg &= ~(MIIM_RTL8211E_TX_DELAY | MIIM_RTL8211E_RX_DELAY);
+	phy_write(phydev, MDIO_DEVAD_NONE, MIIM_RTL8211E_CONFREG, reg | val);
+
+	phy_write(phydev, MDIO_DEVAD_NONE, MIIM_RTL8211F_PAGE_SELECT, 0);
+
+default_delay:
+	genphy_config_aneg(phydev);
+
+	return 0;
+}
+
 static int rtl8211f_config(struct phy_device *phydev)
 {
 	u16 reg;
@@ -410,7 +427,7 @@ static struct phy_driver RTL8211E_driver = {
 	.mask = 0xffffff,
 	.features = PHY_GBIT_FEATURES,
 	.probe = &rtl8211e_probe,
-	.config = &rtl8211x_config,
+	.config = &rtl8211e_config,
 	.startup = &rtl8211e_startup,
 	.shutdown = &genphy_shutdown,
 };