[PATCH net-next 1/2] net: pcs: Introducing support for DWC xpcs Energy Efficient Ethernet

[Michael Sit Wei Hong]

Add DWC xpcs EEE support callbacks.The callback function is used to
set EEE registers on xpcs.

xpcs transparent mode is enabled to allow PHY to detect MAC EEE status.

Signed-off-by: Michael Sit Wei Hong <michael.wei.hong.sit@xxxxxxxxx>
---
 drivers/net/pcs/pcs-xpcs.c   | 51 ++++++++++++++++++++++++++++++++++++
 include/linux/pcs/pcs-xpcs.h |  2 ++
 2 files changed, 53 insertions(+)

diff --git a/drivers/net/pcs/pcs-xpcs.c b/drivers/net/pcs/pcs-xpcs.c
index 944ba105cac1..aa985a5aae8d 100644
--- a/drivers/net/pcs/pcs-xpcs.c
+++ b/drivers/net/pcs/pcs-xpcs.c
@@ -63,6 +63,9 @@
 #define DW_VR_MII_DIG_CTRL1		0x8000
 #define DW_VR_MII_AN_CTRL		0x8001
 #define DW_VR_MII_AN_INTR_STS		0x8002
+/* EEE Mode Control Register */
+#define DW_VR_MII_EEE_MCTRL0		0x8006
+#define DW_VR_MII_EEE_MCTRL1		0x800b
 
 /* VR_MII_DIG_CTRL1 */
 #define DW_VR_MII_DIG_CTRL1_MAC_AUTO_SW		BIT(9)
@@ -86,6 +89,20 @@
 #define DW_VR_MII_C37_ANSGM_SP_1000		0x2
 #define DW_VR_MII_C37_ANSGM_SP_LNKSTS		BIT(4)
 
+/* 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 */
+#define DW_VR_MII_EEE_TX_QUIET_EN		BIT(2)  /* Tx Quiet Enable */
+#define DW_VR_MII_EEE_RX_QUIET_EN		BIT(3)  /* Rx Quiet Enable */
+#define DW_VR_MII_EEE_TX_EN_CTRL		BIT(4)  /* Tx Control Enable */
+#define DW_VR_MII_EEE_RX_EN_CTRL		BIT(7)  /* Rx Control Enable */
+
+#define DW_VR_MII_EEE_MULT_FACT_100NS_SHIFT	8
+#define DW_VR_MII_EEE_MULT_FACT_100NS		GENMASK(11, 8)
+
+/* VR MII EEE Control 1 defines */
+#define DW_VR_MII_EEE_TRN_LPI		BIT(0)	/* Transparent Mode Enable */
+
 static const int xpcs_usxgmii_features[] = {
 	ETHTOOL_LINK_MODE_Pause_BIT,
 	ETHTOOL_LINK_MODE_Asym_Pause_BIT,
@@ -650,6 +667,39 @@ static int xpcs_validate(struct mdio_xpcs_args *xpcs,
 	return 0;
 }
 
+static int xpcs_config_eee(struct mdio_xpcs_args *xpcs, int mult_fact_100ns,
+			   int enable)
+{
+	int ret;
+
+	if (enable) {
+	/* Enable EEE */
+		ret = DW_VR_MII_EEE_LTX_EN | DW_VR_MII_EEE_LRX_EN |
+		      DW_VR_MII_EEE_TX_QUIET_EN | DW_VR_MII_EEE_RX_QUIET_EN |
+		      DW_VR_MII_EEE_TX_EN_CTRL | DW_VR_MII_EEE_RX_EN_CTRL |
+		      mult_fact_100ns << DW_VR_MII_EEE_MULT_FACT_100NS_SHIFT;
+	} else {
+		ret = xpcs_read(xpcs, MDIO_MMD_VEND2, DW_VR_MII_EEE_MCTRL0);
+		if (ret < 0)
+			return ret;
+		ret &= ~(DW_VR_MII_EEE_LTX_EN | DW_VR_MII_EEE_LRX_EN |
+		       DW_VR_MII_EEE_TX_QUIET_EN | DW_VR_MII_EEE_RX_QUIET_EN |
+		       DW_VR_MII_EEE_TX_EN_CTRL | DW_VR_MII_EEE_RX_EN_CTRL |
+		       DW_VR_MII_EEE_MULT_FACT_100NS);
+	}
+
+	ret = xpcs_write(xpcs, MDIO_MMD_VEND2, DW_VR_MII_EEE_MCTRL0, ret);
+	if (ret < 0)
+		return ret;
+
+	ret = xpcs_read(xpcs, MDIO_MMD_VEND2, DW_VR_MII_EEE_MCTRL1);
+	if (ret < 0)
+		return ret;
+
+	ret |= DW_VR_MII_EEE_TRN_LPI;
+	return xpcs_write(xpcs, MDIO_MMD_VEND2, DW_VR_MII_EEE_MCTRL1, ret);
+}
+
 static int xpcs_config_aneg_c37_sgmii(struct mdio_xpcs_args *xpcs)
 {
 	int ret;
@@ -908,6 +958,7 @@ static struct mdio_xpcs_ops xpcs_ops = {
 	.get_state = xpcs_get_state,
 	.link_up = xpcs_link_up,
 	.probe = xpcs_probe,
+	.config_eee = xpcs_config_eee,
 };
 
 struct mdio_xpcs_ops *mdio_xpcs_get_ops(void)
diff --git a/include/linux/pcs/pcs-xpcs.h b/include/linux/pcs/pcs-xpcs.h
index 2cb5188a7ef1..5938ced805f4 100644
--- a/include/linux/pcs/pcs-xpcs.h
+++ b/include/linux/pcs/pcs-xpcs.h
@@ -32,6 +32,8 @@ struct mdio_xpcs_ops {
 	int (*link_up)(struct mdio_xpcs_args *xpcs, int speed,
 		       phy_interface_t interface);
 	int (*probe)(struct mdio_xpcs_args *xpcs, phy_interface_t interface);
+	int (*config_eee)(struct mdio_xpcs_args *xpcs, int mult_fact_100ns,
+			  int enable);
 };
 
 #if IS_ENABLED(CONFIG_PCS_XPCS)
-- 
2.17.1