Add support for configuring MDI-X state of PHY.
Add reporting of resolved MDI-X state in status information.

Tested on AQR113C.

Signed-off-by: Paul Davey <paul.davey@alliedtelesis.co.nz>
---
v2:
 - Renamed aqr_set_polarity to aqr_set_mdix
 - Guard MDI-X state reporting on genphy_c45_aneg_done
 - Link to v1: https://lore.kernel.org/netdev/20241017015407.256737-1-paul.davey@alliedtelesis.co.nz/
---
 drivers/net/phy/aquantia/aquantia_main.c | 52 ++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/drivers/net/phy/aquantia/aquantia_main.c b/drivers/net/phy/aquantia/aquantia_main.c
index 38d0dd5c80a4..bb56a66d2a48 100644
--- a/drivers/net/phy/aquantia/aquantia_main.c
+++ b/drivers/net/phy/aquantia/aquantia_main.c
@@ -54,6 +54,12 @@
 #define MDIO_AN_VEND_PROV_DOWNSHIFT_MASK	GENMASK(3, 0)
 #define MDIO_AN_VEND_PROV_DOWNSHIFT_DFLT	4
 
+#define MDIO_AN_RESVD_VEND_PROV			0xc410
+#define MDIO_AN_RESVD_VEND_PROV_MDIX_AUTO	0
+#define MDIO_AN_RESVD_VEND_PROV_MDIX_MDI	1
+#define MDIO_AN_RESVD_VEND_PROV_MDIX_MDIX	2
+#define MDIO_AN_RESVD_VEND_PROV_MDIX_MASK	GENMASK(1, 0)
+
 #define MDIO_AN_TX_VEND_STATUS1			0xc800
 #define MDIO_AN_TX_VEND_STATUS1_RATE_MASK	GENMASK(3, 1)
 #define MDIO_AN_TX_VEND_STATUS1_10BASET		0
@@ -64,6 +70,9 @@
 #define MDIO_AN_TX_VEND_STATUS1_5000BASET	5
 #define MDIO_AN_TX_VEND_STATUS1_FULL_DUPLEX	BIT(0)
 
+#define MDIO_AN_RESVD_VEND_STATUS1		0xc810
+#define MDIO_AN_RESVD_VEND_STATUS1_MDIX		BIT(8)
+
 #define MDIO_AN_TX_VEND_INT_STATUS1		0xcc00
 #define MDIO_AN_TX_VEND_INT_STATUS1_DOWNSHIFT	BIT(1)
 
@@ -155,12 +164,40 @@ static void aqr107_get_stats(struct phy_device *phydev,
 	}
 }
 
+static int aqr_set_mdix(struct phy_device *phydev, int mdix)
+{
+	u16 val = 0;
+
+	switch (mdix) {
+	case ETH_TP_MDI:
+		val = MDIO_AN_RESVD_VEND_PROV_MDIX_MDI;
+		break;
+	case ETH_TP_MDI_X:
+		val = MDIO_AN_RESVD_VEND_PROV_MDIX_MDIX;
+		break;
+	case ETH_TP_MDI_AUTO:
+	case ETH_TP_MDI_INVALID:
+	default:
+		val = MDIO_AN_RESVD_VEND_PROV_MDIX_AUTO;
+		break;
+	}
+
+	return phy_modify_mmd_changed(phydev, MDIO_MMD_AN, MDIO_AN_RESVD_VEND_PROV,
+				      MDIO_AN_RESVD_VEND_PROV_MDIX_MASK, val);
+}
+
 static int aqr_config_aneg(struct phy_device *phydev)
 {
 	bool changed = false;
 	u16 reg;
 	int ret;
 
+	ret = aqr_set_mdix(phydev, phydev->mdix_ctrl);
+	if (ret < 0)
+		return ret;
+	if (ret > 0)
+		changed = true;
+
 	if (phydev->autoneg == AUTONEG_DISABLE)
 		return genphy_c45_pma_setup_forced(phydev);
 
@@ -278,6 +315,21 @@ static int aqr_read_status(struct phy_device *phydev)
 				 val & MDIO_AN_RX_LP_STAT1_1000BASET_HALF);
 	}
 
+	val = genphy_c45_aneg_done(phydev);
+	if (val < 0)
+		return val;
+	if (val) {
+		val = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_AN_RESVD_VEND_STATUS1);
+		if (val < 0)
+			return val;
+		if (val & MDIO_AN_RESVD_VEND_STATUS1_MDIX)
+			phydev->mdix = ETH_TP_MDI_X;
+		else
+			phydev->mdix = ETH_TP_MDI;
+	} else {
+		phydev->mdix = ETH_TP_MDI_INVALID;
+	}
+
 	return genphy_c45_read_status(phydev);
 }
 
-- 
2.47.0

On 06.11.2024 23:20, Paul Davey wrote:
> Add support for configuring MDI-X state of PHY.
> Add reporting of resolved MDI-X state in status information.
> 
I wonder how relevant this is nowadays. Is there any PHY out there w/o auto MDI-X?
What would be a use case for manually dealing with MDI, and who would do what based
on the MDI-X status information?

> Tested on AQR113C.
> 
> Signed-off-by: Paul Davey <paul.davey@alliedtelesis.co.nz>
> ---
> v2:
>  - Renamed aqr_set_polarity to aqr_set_mdix
>  - Guard MDI-X state reporting on genphy_c45_aneg_done
>  - Link to v1: https://lore.kernel.org/netdev/20241017015407.256737-1-paul.davey@alliedtelesis.co.nz/
> ---
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