Merge branch 'net-phy-dp83867-always-program-r-sgmii-enable-bits'

Sean Anderson says:

====================
net: phy: dp83867: Always program R/SGMII enable bits

The hardware designers at my company neglected to read the datasheet for
this PHY and did not add appropriate resistors to configure it for
SGMII. Add support for configuring the it based on phy-mode instead of
relying on the resistors for a suitable default.
====================

Link: https://patch.msgid.link/20260129171205.3868605-1-sean.anderson@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 23 insertions, 40 deletions

diff --git a/drivers/net/phy/dp83867.c b/drivers/net/phy/dp83867.c
index 5f5de01c41e1..3fb2293f568f 100644
--- a/drivers/net/phy/dp83867.c
+++ b/drivers/net/phy/dp83867.c
@@ -75,6 +75,7 @@
 #define MII_DP83867_MICR_JABBER_INT_EN		BIT(0)
 
 /* RGMIICTL bits */
+#define DP83867_RGMII_EN			BIT(7)
 #define DP83867_RGMII_TX_CLK_DELAY_EN		BIT(1)
 #define DP83867_RGMII_RX_CLK_DELAY_EN		BIT(0)
 
@@ -100,7 +101,7 @@
 #define DP83867_PHYCR_FIFO_DEPTH_MAX		0x03
 #define DP83867_PHYCR_TX_FIFO_DEPTH_MASK	GENMASK(15, 14)
 #define DP83867_PHYCR_RX_FIFO_DEPTH_MASK	GENMASK(13, 12)
-#define DP83867_PHYCR_RESERVED_MASK		BIT(11)
+#define DP83867_PHYCR_SGMII_EN			BIT(11)
 #define DP83867_PHYCR_FORCE_LINK_GOOD		BIT(10)
 
 /* RGMIIDCTL bits */
@@ -744,53 +745,31 @@ static int dp83867_config_init(struct phy_device *phydev)
 	 */
 	phy_disable_eee(phydev);
 
-	if (phy_interface_is_rgmii(phydev) ||
-	    phydev->interface == PHY_INTERFACE_MODE_SGMII) {
-		val = phy_read(phydev, MII_DP83867_PHYCTRL);
-		if (val < 0)
-			return val;
+	val = phy_read(phydev, MII_DP83867_PHYCTRL);
+	if (val < 0)
+		return val;
 
-		val &= ~DP83867_PHYCR_TX_FIFO_DEPTH_MASK;
-		val |= (dp83867->tx_fifo_depth <<
-			DP83867_PHYCR_TX_FIFO_DEPTH_SHIFT);
+	val &= ~DP83867_PHYCR_TX_FIFO_DEPTH_MASK;
+	val |= (dp83867->tx_fifo_depth <<
+		DP83867_PHYCR_TX_FIFO_DEPTH_SHIFT);
 
-		if (phydev->interface == PHY_INTERFACE_MODE_SGMII) {
-			val &= ~DP83867_PHYCR_RX_FIFO_DEPTH_MASK;
-			val |= (dp83867->rx_fifo_depth <<
-				DP83867_PHYCR_RX_FIFO_DEPTH_SHIFT);
-		}
-
-		ret = phy_write(phydev, MII_DP83867_PHYCTRL, val);
-		if (ret)
-			return ret;
+	val &= ~DP83867_PHYCR_SGMII_EN;
+	if (phydev->interface == PHY_INTERFACE_MODE_SGMII) {
+		val &= ~DP83867_PHYCR_RX_FIFO_DEPTH_MASK;
+		val |= (dp83867->rx_fifo_depth <<
+			DP83867_PHYCR_RX_FIFO_DEPTH_SHIFT) |
+		       DP83867_PHYCR_SGMII_EN;
 	}
 
-	if (phy_interface_is_rgmii(phydev)) {
-		val = phy_read(phydev, MII_DP83867_PHYCTRL);
-		if (val < 0)
-			return val;
-
-		/* The code below checks if "port mirroring" N/A MODE4 has been
-		 * enabled during power on bootstrap.
-		 *
-		 * Such N/A mode enabled by mistake can put PHY IC in some
-		 * internal testing mode and disable RGMII transmission.
-		 *
-		 * In this particular case one needs to check STRAP_STS1
-		 * register's bit 11 (marked as RESERVED).
-		 */
-
-		bs = phy_read_mmd(phydev, DP83867_DEVADDR, DP83867_STRAP_STS1);
-		if (bs & DP83867_STRAP_STS1_RESERVED)
-			val &= ~DP83867_PHYCR_RESERVED_MASK;
-
-		ret = phy_write(phydev, MII_DP83867_PHYCTRL, val);
-		if (ret)
-			return ret;
+	ret = phy_write(phydev, MII_DP83867_PHYCTRL, val);
+	if (ret)
+		return ret;
 
+	if (phy_interface_is_rgmii(phydev)) {
 		/* Set up RGMII delays */
 		val = phy_read_mmd(phydev, DP83867_DEVADDR, DP83867_RGMIICTL);
 
+		val |= DP83867_RGMII_EN;
 		val &= ~(DP83867_RGMII_TX_CLK_DELAY_EN | DP83867_RGMII_RX_CLK_DELAY_EN);
 		if (phydev->interface == PHY_INTERFACE_MODE_RGMII_ID)
 			val |= (DP83867_RGMII_TX_CLK_DELAY_EN | DP83867_RGMII_RX_CLK_DELAY_EN);
@@ -806,6 +785,10 @@ static int dp83867_config_init(struct phy_device *phydev)
 		phy_write_mmd(phydev, DP83867_DEVADDR, DP83867_RGMIIDCTL,
 			      dp83867->rx_id_delay |
 			      (dp83867->tx_id_delay << DP83867_RGMII_TX_CLK_DELAY_SHIFT));
+	} else {
+		val = phy_read_mmd(phydev, DP83867_DEVADDR, DP83867_RGMIICTL);
+		val &= ~DP83867_RGMII_EN;
+		phy_write_mmd(phydev, DP83867_DEVADDR, DP83867_RGMIICTL, val);
 	}
 
 	/* If specified, set io impedance */