Merge branch 'fixes-for-mtk_eth_soc'

Bjørn Mork says:

====================
Fix mtk_eth_soc sgmii configuration.

This has been tested on a MT7986 with a Maxlinear GPY211C phy
permanently attached to the second SoC mac.
====================

Link: https://lore.kernel.org/r/20230201182331.943411-1-bjorn@mork.noSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/mediatek/mtk_eth_soc.h

@@ -519,7 +519,7 @@
 #define SGMII_SPEED_10			FIELD_PREP(SGMII_SPEED_MASK, 0)
 #define SGMII_SPEED_100			FIELD_PREP(SGMII_SPEED_MASK, 1)
 #define SGMII_SPEED_1000		FIELD_PREP(SGMII_SPEED_MASK, 2)
-#define SGMII_DUPLEX_FULL		BIT(4)
+#define SGMII_DUPLEX_HALF		BIT(4)
 #define SGMII_IF_MODE_BIT5		BIT(5)
 #define SGMII_REMOTE_FAULT_DIS		BIT(8)
 #define SGMII_CODE_SYNC_SET_VAL		BIT(9)
@@ -1036,11 +1036,13 @@ struct mtk_soc_data {
  * @regmap:            The register map pointing at the range used to setup
  *                     SGMII modes
  * @ana_rgc3:          The offset refers to register ANA_RGC3 related to regmap
+ * @interface:         Currently configured interface mode
  * @pcs:               Phylink PCS structure
  */
 struct mtk_pcs {
 	struct regmap	*regmap;
 	u32             ana_rgc3;
+	phy_interface_t	interface;
 	struct phylink_pcs pcs;
 };
 

drivers/net/ethernet/mediatek/mtk_sgmii.c

@@ -43,11 +43,6 @@ static int mtk_pcs_config(struct phylink_pcs *pcs, unsigned int mode,
 	int advertise, link_timer;
 	bool changed, use_an;
 
-	if (interface == PHY_INTERFACE_MODE_2500BASEX)
-		rgc3 = RG_PHY_SPEED_3_125G;
-	else
-		rgc3 = 0;
-
 	advertise = phylink_mii_c22_pcs_encode_advertisement(interface,
 							     advertising);
 	if (advertise < 0)
@@ -88,9 +83,22 @@ static int mtk_pcs_config(struct phylink_pcs *pcs, unsigned int mode,
 		bmcr = 0;
 	}
 
-	/* Configure the underlying interface speed */
-	regmap_update_bits(mpcs->regmap, mpcs->ana_rgc3,
-			   RG_PHY_SPEED_3_125G, rgc3);
+	if (mpcs->interface != interface) {
+		/* PHYA power down */
+		regmap_update_bits(mpcs->regmap, SGMSYS_QPHY_PWR_STATE_CTRL,
+				   SGMII_PHYA_PWD, SGMII_PHYA_PWD);
+
+		if (interface == PHY_INTERFACE_MODE_2500BASEX)
+			rgc3 = RG_PHY_SPEED_3_125G;
+		else
+			rgc3 = 0;
+
+		/* Configure the underlying interface speed */
+		regmap_update_bits(mpcs->regmap, mpcs->ana_rgc3,
+				   RG_PHY_SPEED_3_125G, rgc3);
+
+		mpcs->interface = interface;
+	}
 
 	/* Update the advertisement, noting whether it has changed */
 	regmap_update_bits_check(mpcs->regmap, SGMSYS_PCS_ADVERTISE,
@@ -108,9 +116,17 @@ static int mtk_pcs_config(struct phylink_pcs *pcs, unsigned int mode,
 	regmap_update_bits(mpcs->regmap, SGMSYS_PCS_CONTROL_1,
 			   SGMII_AN_RESTART | SGMII_AN_ENABLE, bmcr);
 
-	/* Release PHYA power down state */
-	regmap_update_bits(mpcs->regmap, SGMSYS_QPHY_PWR_STATE_CTRL,
-			   SGMII_PHYA_PWD, 0);
+	/* Release PHYA power down state
+	 * Only removing bit SGMII_PHYA_PWD isn't enough.
+	 * There are cases when the SGMII_PHYA_PWD register contains 0x9 which
+	 * prevents SGMII from working. The SGMII still shows link but no traffic
+	 * can flow. Writing 0x0 to the PHYA_PWD register fix the issue. 0x0 was
+	 * taken from a good working state of the SGMII interface.
+	 * Unknown how much the QPHY needs but it is racy without a sleep.
+	 * Tested on mt7622 & mt7986.
+	 */
+	usleep_range(50, 100);
+	regmap_write(mpcs->regmap, SGMSYS_QPHY_PWR_STATE_CTRL, 0);
 
 	return changed;
 }
@@ -138,11 +154,11 @@ static void mtk_pcs_link_up(struct phylink_pcs *pcs, unsigned int mode,
 		else
 			sgm_mode = SGMII_SPEED_1000;
 
-		if (duplex == DUPLEX_FULL)
-			sgm_mode |= SGMII_DUPLEX_FULL;
+		if (duplex != DUPLEX_FULL)
+			sgm_mode |= SGMII_DUPLEX_HALF;
 
 		regmap_update_bits(mpcs->regmap, SGMSYS_SGMII_MODE,
-				   SGMII_DUPLEX_FULL | SGMII_SPEED_MASK,
+				   SGMII_DUPLEX_HALF | SGMII_SPEED_MASK,
 				   sgm_mode);
 	}
 }
@@ -171,6 +187,8 @@ int mtk_sgmii_init(struct mtk_sgmii *ss, struct device_node *r, u32 ana_rgc3)
 			return PTR_ERR(ss->pcs[i].regmap);
 
 		ss->pcs[i].pcs.ops = &mtk_pcs_ops;
+		ss->pcs[i].pcs.poll = true;
+		ss->pcs[i].interface = PHY_INTERFACE_MODE_NA;
 	}
 
 	return 0;