From 3265f421887847db9ae2c01a00645e33608556d8 Mon Sep 17 00:00:00 2001
From: Robert Hancock <robert.hancock@calian.com>
Date: Tue, 25 Jan 2022 10:54:09 -0600
Subject: [PATCH] net: phy: at803x: add fiber support

Previously this driver always forced the copper page to be selected,
however for AR8031 in 100Base-FX or 1000Base-X modes, the fiber page
needs to be selected. Set the appropriate mode based on the hardware
mode_cfg strap selection.

Enable the appropriate interrupt bits to detect fiber-side link up
or down events.

Update config_aneg and read_status methods to use the appropriate
Clause 37 calls when fiber mode is in use.

Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 drivers/net/phy/at803x.c | 76 +++++++++++++++++++++++++++++++++++-----
 1 file changed, 67 insertions(+), 9 deletions(-)

--- a/drivers/net/phy/at803x.c
+++ b/drivers/net/phy/at803x.c
@@ -48,6 +48,8 @@
 #define AT803X_INTR_ENABLE_PAGE_RECEIVED	BIT(12)
 #define AT803X_INTR_ENABLE_LINK_FAIL		BIT(11)
 #define AT803X_INTR_ENABLE_LINK_SUCCESS		BIT(10)
+#define AT803X_INTR_ENABLE_LINK_FAIL_BX		BIT(8)
+#define AT803X_INTR_ENABLE_LINK_SUCCESS_BX	BIT(7)
 #define AT803X_INTR_ENABLE_WIRESPEED_DOWNGRADE	BIT(5)
 #define AT803X_INTR_ENABLE_POLARITY_CHANGED	BIT(1)
 #define AT803X_INTR_ENABLE_WOL			BIT(0)
@@ -82,6 +84,17 @@
 
 #define AT803X_MODE_CFG_MASK			0x0F
 #define AT803X_MODE_CFG_SGMII			0x01
+#define AT803X_MODE_CFG_BASET_RGMII		0x00
+#define AT803X_MODE_CFG_BASET_SGMII		0x01
+#define AT803X_MODE_CFG_BX1000_RGMII_50OHM	0x02
+#define AT803X_MODE_CFG_BX1000_RGMII_75OHM	0x03
+#define AT803X_MODE_CFG_BX1000_CONV_50OHM	0x04
+#define AT803X_MODE_CFG_BX1000_CONV_75OHM	0x05
+#define AT803X_MODE_CFG_FX100_RGMII_50OHM	0x06
+#define AT803X_MODE_CFG_FX100_CONV_50OHM	0x07
+#define AT803X_MODE_CFG_RGMII_AUTO_MDET		0x0B
+#define AT803X_MODE_CFG_FX100_RGMII_75OHM	0x0E
+#define AT803X_MODE_CFG_FX100_CONV_75OHM	0x0F
 
 #define AT803X_PSSR			0x11	/*PHY-Specific Status Register*/
 #define AT803X_PSSR_MR_AN_COMPLETE	0x0200
@@ -189,6 +202,8 @@ struct at803x_priv {
 #define AT803X_KEEP_PLL_ENABLED	BIT(0)	/* don't turn off internal PLL */
 	u16 clk_25m_reg;
 	u16 clk_25m_mask;
+	bool is_fiber;
+	bool is_1000basex;
 	struct regulator_dev *vddio_rdev;
 	struct regulator_dev *vddh_rdev;
 	struct regulator *vddio;
@@ -651,7 +666,33 @@ static int at803x_probe(struct phy_devic
 			return ret;
 	}
 
+	if (phydev->drv->phy_id == ATH8031_PHY_ID) {
+		int ccr = phy_read(phydev, AT803X_REG_CHIP_CONFIG);
+		int mode_cfg;
+
+		if (ccr < 0)
+			goto err;
+		mode_cfg = ccr & AT803X_MODE_CFG_MASK;
+
+		switch (mode_cfg) {
+		case AT803X_MODE_CFG_BX1000_RGMII_50OHM:
+		case AT803X_MODE_CFG_BX1000_RGMII_75OHM:
+			priv->is_1000basex = true;
+			fallthrough;
+		case AT803X_MODE_CFG_FX100_RGMII_50OHM:
+		case AT803X_MODE_CFG_FX100_RGMII_75OHM:
+			priv->is_fiber = true;
+			break;
+		}
+	}
+
 	return 0;
+
+err:
+	if (priv->vddio)
+		regulator_disable(priv->vddio);
+
+	return ret;
 }
 
 static void at803x_remove(struct phy_device *phydev)
@@ -664,6 +705,7 @@ static void at803x_remove(struct phy_dev
 
 static int at803x_get_features(struct phy_device *phydev)
 {
+	struct at803x_priv *priv = phydev->priv;
 	int err;
 
 	err = genphy_read_abilities(phydev);
@@ -681,12 +723,13 @@ static int at803x_get_features(struct ph
 	 * As a result of that, ESTATUS_1000_XFULL is set
 	 * to 1 even when operating in copper TP mode.
 	 *
-	 * Remove this mode from the supported link modes,
-	 * as this driver currently only supports copper
-	 * operation.
+	 * Remove this mode from the supported link modes
+	 * when not operating in 1000BaseX mode.
 	 */
-	linkmode_clear_bit(ETHTOOL_LINK_MODE_1000baseX_Full_BIT,
-			   phydev->supported);
+	if (!priv->is_1000basex)
+		linkmode_clear_bit(ETHTOOL_LINK_MODE_1000baseX_Full_BIT,
+				   phydev->supported);
+
 	return 0;
 }
 
@@ -725,15 +768,18 @@ static int at8031_pll_config(struct phy_
 
 static int at803x_config_init(struct phy_device *phydev)
 {
+	struct at803x_priv *priv = phydev->priv;
 	int ret;
 
 	if (phydev->drv->phy_id == ATH8031_PHY_ID) {
 		/* Some bootloaders leave the fiber page selected.
-		 * Switch to the copper page, as otherwise we read
-		 * the PHY capabilities from the fiber side.
+		 * Switch to the appropriate page (fiber or copper), as otherwise we
+		 * read the PHY capabilities from the wrong page.
 		 */
 		phy_lock_mdio_bus(phydev);
-		ret = at803x_write_page(phydev, AT803X_PAGE_COPPER);
+		ret = at803x_write_page(phydev,
+					priv->is_fiber ? AT803X_PAGE_FIBER :
+							 AT803X_PAGE_COPPER);
 		phy_unlock_mdio_bus(phydev);
 		if (ret)
 			return ret;
@@ -782,6 +828,7 @@ static int at803x_ack_interrupt(struct p
 
 static int at803x_config_intr(struct phy_device *phydev)
 {
+	struct at803x_priv *priv = phydev->priv;
 	int err;
 	int value;
 
@@ -793,6 +840,10 @@ static int at803x_config_intr(struct phy
 		value |= AT803X_INTR_ENABLE_DUPLEX_CHANGED;
 		value |= AT803X_INTR_ENABLE_LINK_FAIL;
 		value |= AT803X_INTR_ENABLE_LINK_SUCCESS;
+		if (priv->is_fiber) {
+			value |= AT803X_INTR_ENABLE_LINK_FAIL_BX;
+			value |= AT803X_INTR_ENABLE_LINK_SUCCESS_BX;
+		}
 
 		err = phy_write(phydev, AT803X_INTR_ENABLE, value);
 	}
@@ -859,8 +910,12 @@ static int at803x_aneg_done(struct phy_d
 
 static int at803x_read_status(struct phy_device *phydev)
 {
+	struct at803x_priv *priv = phydev->priv;
 	int ss, err, old_link = phydev->link;
 
+	if (priv->is_1000basex)
+		return genphy_c37_read_status(phydev);
+
 	/* Update the link, but return if there was an error */
 	err = genphy_update_link(phydev);
 	if (err)
@@ -959,6 +1014,7 @@ static int at803x_config_mdix(struct phy
 
 static int at803x_config_aneg(struct phy_device *phydev)
 {
+	struct at803x_priv *priv = phydev->priv;
 	int ret;
 
 	ret = at803x_config_mdix(phydev, phydev->mdix_ctrl);
@@ -975,6 +1031,9 @@ static int at803x_config_aneg(struct phy
 			return ret;
 	}
 
+	if (priv->is_1000basex)
+		return genphy_c37_config_aneg(phydev);
+
 	return genphy_config_aneg(phydev);
 }
 
