net: pcs: xpcs: add 1000BASE-X AN interrupt support

Enable CL37 AN complete interrupt for DW XPCS. It requires to clear the
bit(0) [CL37_ANCMPLT_INTR] of VR_MII_AN_INTR_STS after AN completed.

And there is a quirk for Wangxun devices to enable CL37 AN in backplane
configurations because of the special hardware design.
Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/pcs/pcs-xpcs.c

@@ -755,6 +755,9 @@ static int xpcs_config_aneg_c37_1000basex(struct dw_xpcs *xpcs,
 	int ret, mdio_ctrl, adv;
 	bool changed = 0;
 
+	if (xpcs->dev_flag == DW_DEV_TXGBE)
+		xpcs_write_vpcs(xpcs, DW_VR_XS_PCS_DIG_CTRL1, DW_CL37_BP | DW_EN_VSMMD1);
+
 	/* According to Chap 7.12, to set 1000BASE-X C37 AN, AN must
 	 * be disabled first:-
 	 * 1) VR_MII_MMD_CTRL Bit(12)[AN_ENABLE] = 0b
@@ -776,6 +779,8 @@ static int xpcs_config_aneg_c37_1000basex(struct dw_xpcs *xpcs,
 		return ret;
 
 	ret &= ~DW_VR_MII_PCS_MODE_MASK;
+	if (!xpcs->pcs.poll)
+		ret |= DW_VR_MII_AN_INTR_EN;
 	ret = xpcs_write(xpcs, MDIO_MMD_VEND2, DW_VR_MII_AN_CTRL, ret);
 	if (ret < 0)
 		return ret;
@@ -1029,6 +1034,17 @@ static int xpcs_get_state_c37_1000basex(struct dw_xpcs *xpcs,
 		if (bmsr < 0)
 			return bmsr;
 
+		/* Clear AN complete interrupt */
+		if (!xpcs->pcs.poll) {
+			int an_intr;
+
+			an_intr = xpcs_read(xpcs, MDIO_MMD_VEND2, DW_VR_MII_AN_INTR_STS);
+			if (an_intr & DW_VR_MII_AN_STS_C37_ANCMPLT_INTR) {
+				an_intr &= ~DW_VR_MII_AN_STS_C37_ANCMPLT_INTR;
+				xpcs_write(xpcs, MDIO_MMD_VEND2, DW_VR_MII_AN_INTR_STS, an_intr);
+			}
+		}
+
 		phylink_mii_c22_pcs_decode_state(state, bmsr, lpa);
 	}
 
@@ -1319,9 +1335,10 @@ static struct dw_xpcs *xpcs_create(struct mdio_device *mdiodev,
 
 		xpcs->pcs.ops = &xpcs_phylink_ops;
 		xpcs->pcs.neg_mode = true;
-		xpcs->pcs.poll = true;
 
 		if (xpcs->dev_flag != DW_DEV_TXGBE) {
+			xpcs->pcs.poll = true;
+
 			ret = xpcs_soft_reset(xpcs, compat);
 			if (ret)
 				goto out;

drivers/net/pcs/pcs-xpcs.h

@@ -18,6 +18,7 @@
 #define DW_VR_XS_PCS_DIG_CTRL1		0x0000
 #define DW_VR_RST			BIT(15)
 #define DW_EN_VSMMD1			BIT(13)
+#define DW_CL37_BP			BIT(12)
 #define DW_VR_XS_PCS_DIG_STS		0x0010
 #define DW_RXFIFO_ERR			GENMASK(6, 5)
 #define DW_PSEQ_ST			GENMASK(4, 2)
@@ -80,8 +81,10 @@
 #define DW_VR_MII_PCS_MODE_MASK			GENMASK(2, 1)
 #define DW_VR_MII_PCS_MODE_C37_1000BASEX	0x0
 #define DW_VR_MII_PCS_MODE_C37_SGMII		0x2
+#define DW_VR_MII_AN_INTR_EN			BIT(0)
 
 /* VR_MII_AN_INTR_STS */
+#define DW_VR_MII_AN_STS_C37_ANCMPLT_INTR	BIT(0)
 #define DW_VR_MII_AN_STS_C37_ANSGM_FD		BIT(1)
 #define DW_VR_MII_AN_STS_C37_ANSGM_SP_SHIFT	2
 #define DW_VR_MII_AN_STS_C37_ANSGM_SP		GENMASK(3, 2)