[PATCH net-next v6 2/3] net: pcs: add 2500BASEX support for Intel mGbE controller

[Michael Sit Wei Hong <michael.wei.hong.sit@intel.com>]

From: Voon Weifeng <weifeng.voon@intel.com>

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.
v4: Fix indentation error

Signed-off-by: Voon Weifeng <weifeng.voon@intel.com>
Signed-off-by: Michael Sit Wei Hong <michael.wei.hong.sit@intel.com>
---
 drivers/net/pcs/pcs-xpcs.c   | 56 ++++++++++++++++++++++++++++++++++++
 include/linux/pcs/pcs-xpcs.h |  1 +
 2 files changed, 57 insertions(+)

diff --git a/drivers/net/pcs/pcs-xpcs.c b/drivers/net/pcs/pcs-xpcs.c
index 34164437c135..98c4a3973402 100644
--- a/drivers/net/pcs/pcs-xpcs.c
+++ b/drivers/net/pcs/pcs-xpcs.c
@@ -57,9 +57,12 @@
 
 /* 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
@@ -86,6 +89,11 @@
 #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 +169,14 @@ 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,
 };
@@ -177,11 +193,17 @@ static const phy_interface_t xpcs_sgmii_interfaces[] = {
 	PHY_INTERFACE_MODE_SGMII,
 };
 
+static const phy_interface_t xpcs_2500basex_interfaces[] = {
+	PHY_INTERFACE_MODE_2500BASEX,
+	PHY_INTERFACE_MODE_MAX,
+};
+
 enum {
 	DW_XPCS_USXGMII,
 	DW_XPCS_10GKR,
 	DW_XPCS_XLGMII,
 	DW_XPCS_SGMII,
+	DW_XPCS_2500BASEX,
 	DW_XPCS_INTERFACE_MAX,
 };
 
@@ -306,6 +328,7 @@ 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:
@@ -804,6 +827,28 @@ 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);
+}
+
 static int xpcs_do_config(struct mdio_xpcs_args *xpcs,
 			  phy_interface_t interface, unsigned int mode)
 {
@@ -827,6 +872,11 @@ static int xpcs_do_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;
 	}
@@ -1023,6 +1073,12 @@ static const struct xpcs_compat synopsys_xpcs_compat[DW_XPCS_INTERFACE_MAX] = {
 		.num_interfaces = ARRAY_SIZE(xpcs_sgmii_interfaces),
 		.an_mode = DW_AN_C37_SGMII,
 	},
+	[DW_XPCS_2500BASEX] = {
+		.supported = xpcs_2500basex_features,
+		.interface = xpcs_2500basex_interfaces,
+		.num_interfaces = ARRAY_SIZE(xpcs_2500basex_features),
+		.an_mode = DW_2500BASEX,
+	},
 };
 
 static const struct xpcs_id xpcs_id_list[] = {
diff --git a/include/linux/pcs/pcs-xpcs.h b/include/linux/pcs/pcs-xpcs.h
index 0860a5b59f10..4d815f03b4b2 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 xpcs_id;
 
-- 
2.17.1