[PATCH net-next v3 2/3] net: pcs: add 2500BASEX support for Intel mGbE controller

[Michael Sit Wei Hong]

From: Voon Weifeng <weifeng.voon@xxxxxxxxx>

XPCS IP supports 2500BASEX as PHY interface. It is configured as
autonegotiation disable to cater for PHYs that does not supports 2500BASEX
autonegotiation.

v2: Add supported link speed masking.
v3: Restructure to introduce xpcs_config_2500basex() used to configure the
    xpcs for 2.5G speeds. Added 2500BASEX specific information for
    configuration.

Signed-off-by: Voon Weifeng <weifeng.voon@xxxxxxxxx>
Signed-off-by: Michael Sit Wei Hong <michael.wei.hong.sit@xxxxxxxxx>
---
 drivers/net/pcs/pcs-xpcs.c   | 60 ++++++++++++++++++++++++++++++++++++
 include/linux/pcs/pcs-xpcs.h |  1 +
 2 files changed, 61 insertions(+)

diff --git a/drivers/net/pcs/pcs-xpcs.c b/drivers/net/pcs/pcs-xpcs.c
index aa985a5aae8d..98f822e1e5d5 100644
--- a/drivers/net/pcs/pcs-xpcs.c
+++ b/drivers/net/pcs/pcs-xpcs.c
@@ -16,6 +16,7 @@
 #define SYNOPSYS_XPCS_10GKR_ID		0x7996ced0
 #define SYNOPSYS_XPCS_XLGMII_ID		0x7996ced0
 #define SYNOPSYS_XPCS_SGMII_ID		0x7996ced0
+#define SYNOPSYS_XPCS_2500BASEX_ID	0x7996ced0
 #define SYNOPSYS_XPCS_MASK		0xffffffff
 
 /* Vendor regs access */
@@ -60,9 +61,14 @@
 
 /* Clause 37 Defines */
 /* VR MII MMD registers offsets */
+#define DW_VR_MII_MMD_CTRL		0x0000
 #define DW_VR_MII_DIG_CTRL1		0x8000
 #define DW_VR_MII_AN_CTRL		0x8001
 #define DW_VR_MII_AN_INTR_STS		0x8002
+
+/* Enable 2.5G Mode */
+#define DW_VR_MII_DIG_CTRL1_2G5_EN	BIT(2)
+
 /* EEE Mode Control Register */
 #define DW_VR_MII_EEE_MCTRL0		0x8006
 #define DW_VR_MII_EEE_MCTRL1		0x800b
@@ -89,6 +95,11 @@
 #define DW_VR_MII_C37_ANSGM_SP_1000		0x2
 #define DW_VR_MII_C37_ANSGM_SP_LNKSTS		BIT(4)
 
+/* SR MII MMD Control defines */
+#define AN_CL37_EN		BIT(12)	/* Enable Clause 37 auto-nego */
+#define SGMII_SPEED_SS13	BIT(13)	/* SGMII speed along with SS6 */
+#define SGMII_SPEED_SS6		BIT(6)	/* SGMII speed along with SS13 */
+
 /* VR MII EEE Control 0 defines */
 #define DW_VR_MII_EEE_LTX_EN		BIT(0)  /* LPI Tx Enable */
 #define DW_VR_MII_EEE_LRX_EN		BIT(1)  /* LPI Rx Enable */
@@ -161,6 +172,14 @@ static const int xpcs_sgmii_features[] = {
 	__ETHTOOL_LINK_MODE_MASK_NBITS,
 };
 
+static const int xpcs_2500basex_features[] = {
+	ETHTOOL_LINK_MODE_Asym_Pause_BIT,
+	ETHTOOL_LINK_MODE_Autoneg_BIT,
+	ETHTOOL_LINK_MODE_2500baseX_Full_BIT,
+	ETHTOOL_LINK_MODE_2500baseT_Full_BIT,
+	__ETHTOOL_LINK_MODE_MASK_NBITS,
+};
+
 static const phy_interface_t xpcs_usxgmii_interfaces[] = {
 	PHY_INTERFACE_MODE_USXGMII,
 	PHY_INTERFACE_MODE_MAX,
@@ -181,6 +200,11 @@ static const phy_interface_t xpcs_sgmii_interfaces[] = {
 	PHY_INTERFACE_MODE_MAX,
 };
 
+static const phy_interface_t xpcs_2500basex_interfaces[] = {
+	PHY_INTERFACE_MODE_2500BASEX,
+	PHY_INTERFACE_MODE_MAX,
+};
+
 static struct xpcs_id {
 	u32 id;
 	u32 mask;
@@ -212,6 +236,12 @@ static struct xpcs_id {
 		.supported = xpcs_sgmii_features,
 		.interface = xpcs_sgmii_interfaces,
 		.an_mode = DW_AN_C37_SGMII,
+	}, {
+		.id = SYNOPSYS_XPCS_2500BASEX_ID,
+		.mask = SYNOPSYS_XPCS_MASK,
+		.supported = xpcs_2500basex_features,
+		.interface = xpcs_2500basex_interfaces,
+		.an_mode = DW_2500BASEX,
 	},
 };
 
@@ -275,6 +305,7 @@ static int xpcs_soft_reset(struct mdio_xpcs_args *xpcs)
 		dev = MDIO_MMD_PCS;
 		break;
 	case DW_AN_C37_SGMII:
+	case DW_2500BASEX:
 		dev = MDIO_MMD_VEND2;
 		break;
 	default:
@@ -741,6 +772,30 @@ static int xpcs_config_aneg_c37_sgmii(struct mdio_xpcs_args *xpcs)
 	return xpcs_write(xpcs, MDIO_MMD_VEND2, DW_VR_MII_DIG_CTRL1, ret);
 }
 
+static int xpcs_config_2500basex(struct mdio_xpcs_args *xpcs)
+{
+	int ret;
+
+		ret = xpcs_read(xpcs, MDIO_MMD_VEND2, DW_VR_MII_DIG_CTRL1);
+		if (ret < 0)
+			return ret;
+		ret |= DW_VR_MII_DIG_CTRL1_2G5_EN;
+		ret &= ~DW_VR_MII_DIG_CTRL1_MAC_AUTO_SW;
+		ret = xpcs_write(xpcs, MDIO_MMD_VEND2, DW_VR_MII_DIG_CTRL1, ret);
+		if (ret < 0)
+			return ret;
+
+		ret = xpcs_read(xpcs, MDIO_MMD_VEND2, DW_VR_MII_MMD_CTRL);
+		if (ret < 0)
+			return ret;
+		ret &= ~AN_CL37_EN;
+		ret |= SGMII_SPEED_SS6;
+		ret &= ~SGMII_SPEED_SS13;
+		return xpcs_write(xpcs, MDIO_MMD_VEND2, DW_VR_MII_MMD_CTRL, ret);
+
+	return 0;
+}
+
 static int xpcs_config(struct mdio_xpcs_args *xpcs,
 		       const struct phylink_link_state *state)
 {
@@ -759,6 +814,11 @@ static int xpcs_config(struct mdio_xpcs_args *xpcs,
 		if (ret)
 			return ret;
 		break;
+	case DW_2500BASEX:
+		ret = xpcs_config_2500basex(xpcs);
+		if (ret)
+			return ret;
+		break;
 	default:
 		return -1;
 	}
diff --git a/include/linux/pcs/pcs-xpcs.h b/include/linux/pcs/pcs-xpcs.h
index 5938ced805f4..b358bbb34bd3 100644
--- a/include/linux/pcs/pcs-xpcs.h
+++ b/include/linux/pcs/pcs-xpcs.h
@@ -13,6 +13,7 @@
 /* AN mode */
 #define DW_AN_C73			1
 #define DW_AN_C37_SGMII			2
+#define DW_2500BASEX			3
 
 struct mdio_xpcs_args {
 	__ETHTOOL_DECLARE_LINK_MODE_MASK(supported);
-- 
2.17.1