[PATCH net-next v3 10/15] net: phy: at803x: implement ethtool access to SmartEEE functionality

[Oleksij Rempel <o.rempel@pengutronix.de>]

If AR8035 PHY is used with a MAC without EEE support
(iMX6, etc), then we need to process ethtool_eee::tx_lpi_timer and
tx_lpi_enabled by the PHY driver. So, add get/set_eee support for this
functionality.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
 drivers/net/phy/at803x.c | 109 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 104 insertions(+), 5 deletions(-)

diff --git a/drivers/net/phy/at803x.c b/drivers/net/phy/at803x.c
index 22f4458274aa..9eb4439b0afc 100644
--- a/drivers/net/phy/at803x.c
+++ b/drivers/net/phy/at803x.c
@@ -166,8 +166,18 @@
 
 #define AT803X_MMD3_SMARTEEE_CTL1		0x805b
 #define AT803X_MMD3_SMARTEEE_CTL2		0x805c
+#define AT803X_MMD3_SMARTEEE_LPI_TIME_LOW	GENMASK(15, 0)
+#define AT803X_MMD3_SMARTEEE_LPI_TIME_15_0	GENMASK(15, 0)
 #define AT803X_MMD3_SMARTEEE_CTL3		0x805d
 #define AT803X_MMD3_SMARTEEE_CTL3_LPI_EN	BIT(8)
+#define AT803X_MMD3_SMARTEEE_LPI_TIME_HIGH	GENMASK(7, 0)
+#define AT803X_MMD3_SMARTEEE_LPI_TIME_23_16	GENMASK(23, 16)
+/* Tx LPI timer resolution */
+#define AT803X_MMD3_SMARTEEE_LPI_TIME_RESOL_NS	163840
+#define AT803X_MMD3_SMARTEEE_LPI_TIME_MAX_US	\
+	((GENMASK(23, 0) * AT803X_MMD3_SMARTEEE_LPI_TIME_RESOL_NS) / \
+	       NSEC_PER_USEC)
+#define AT803X_MMD3_SMARTEEE_LPI_TIME_DEF_US	335544
 
 #define ATH9331_PHY_ID				0x004dd041
 #define ATH8030_PHY_ID				0x004dd076
@@ -951,17 +961,26 @@ static int at803x_get_features(struct phy_device *phydev)
 	return 0;
 }
 
-static int at803x_smarteee_config(struct phy_device *phydev)
+static int at803x_smarteee_config(struct phy_device *phydev, bool enable,
+				  u32 tx_lpi_timer_us)
 {
 	struct at803x_priv *priv = phydev->priv;
+	u64 tx_lpi_timer_raw;
+	u64 tx_lpi_timer_ns;
 	u16 mask = 0, val = 0;
 	int ret;
 
-	if (priv->flags & AT803X_DISABLE_SMARTEEE)
+	if (priv->flags & AT803X_DISABLE_SMARTEEE || !enable)
 		return phy_modify_mmd(phydev, MDIO_MMD_PCS,
 				      AT803X_MMD3_SMARTEEE_CTL3,
 				      AT803X_MMD3_SMARTEEE_CTL3_LPI_EN, 0);
 
+	if (tx_lpi_timer_us > AT803X_MMD3_SMARTEEE_LPI_TIME_MAX_US) {
+		phydev_err(phydev, "Max LPI timer is %lu microsecs\n",
+			   AT803X_MMD3_SMARTEEE_LPI_TIME_MAX_US);
+		return -EINVAL;
+	}
+
 	if (priv->smarteee_lpi_tw_1g) {
 		mask |= 0xff00;
 		val |= priv->smarteee_lpi_tw_1g << 8;
@@ -978,9 +997,27 @@ static int at803x_smarteee_config(struct phy_device *phydev)
 	if (ret)
 		return ret;
 
+	tx_lpi_timer_ns = tx_lpi_timer_us * NSEC_PER_USEC;
+	tx_lpi_timer_raw =
+		DIV_ROUND_CLOSEST_ULL(tx_lpi_timer_ns,
+				      AT803X_MMD3_SMARTEEE_LPI_TIME_RESOL_NS);
+	val = FIELD_PREP(AT803X_MMD3_SMARTEEE_LPI_TIME_LOW,
+			 FIELD_GET(AT803X_MMD3_SMARTEEE_LPI_TIME_15_0,
+				   tx_lpi_timer_raw));
+
+	ret = phy_write_mmd(phydev, MDIO_MMD_PCS, AT803X_MMD3_SMARTEEE_CTL2,
+			    val);
+	if (ret)
+		return ret;
+
+	val = AT803X_MMD3_SMARTEEE_CTL3_LPI_EN |
+		FIELD_PREP(AT803X_MMD3_SMARTEEE_LPI_TIME_HIGH,
+			   FIELD_GET(AT803X_MMD3_SMARTEEE_LPI_TIME_23_16,
+				     tx_lpi_timer_raw));
+
 	return phy_modify_mmd(phydev, MDIO_MMD_PCS, AT803X_MMD3_SMARTEEE_CTL3,
-			      AT803X_MMD3_SMARTEEE_CTL3_LPI_EN,
-			      AT803X_MMD3_SMARTEEE_CTL3_LPI_EN);
+			      AT803X_MMD3_SMARTEEE_CTL3_LPI_EN |
+			      AT803X_MMD3_SMARTEEE_LPI_TIME_HIGH, val);
 }
 
 static int at803x_clk_out_config(struct phy_device *phydev)
@@ -1067,7 +1104,8 @@ static int at803x_config_init(struct phy_device *phydev)
 	if (ret < 0)
 		return ret;
 
-	ret = at803x_smarteee_config(phydev);
+	ret = at803x_smarteee_config(phydev, true,
+				     AT803X_MMD3_SMARTEEE_LPI_TIME_DEF_US);
 	if (ret < 0)
 		return ret;
 
@@ -1612,6 +1650,65 @@ static int at803x_cable_test_start(struct phy_device *phydev)
 	return 0;
 }
 
+static int at803x_get_eee(struct phy_device *phydev, struct ethtool_eee *data)
+{
+	struct at803x_priv *priv = phydev->priv;
+	u32 tx_timer_raw;
+	u64 tx_timer_ns;
+	int ret;
+
+	/* If SmartEEE is not enabled, it is expected that tx_lpi_* fields
+	 * are processed by the MAC driver.
+	 */
+	if (priv->flags & AT803X_DISABLE_SMARTEEE)
+		return genphy_c45_ethtool_get_eee(phydev, data);
+
+	ret = phy_read_mmd(phydev, MDIO_MMD_PCS,
+			   AT803X_MMD3_SMARTEEE_CTL2);
+	tx_timer_raw = FIELD_PREP(AT803X_MMD3_SMARTEEE_LPI_TIME_15_0,
+				  FIELD_GET(AT803X_MMD3_SMARTEEE_LPI_TIME_LOW,
+					    ret));
+	if (ret < 0)
+		return ret;
+
+	ret = phy_read_mmd(phydev, MDIO_MMD_PCS,
+			   AT803X_MMD3_SMARTEEE_CTL3);
+	if (ret < 0)
+		return ret;
+
+	tx_timer_raw |= FIELD_PREP(AT803X_MMD3_SMARTEEE_LPI_TIME_23_16,
+				   FIELD_GET(AT803X_MMD3_SMARTEEE_LPI_TIME_HIGH,
+					     ret));
+	tx_timer_ns = tx_timer_raw * AT803X_MMD3_SMARTEEE_LPI_TIME_RESOL_NS;
+	data->tx_lpi_timer = DIV_ROUND_CLOSEST_ULL(tx_timer_ns, NSEC_PER_USEC);
+
+	data->tx_lpi_enabled = !!(ret & AT803X_MMD3_SMARTEEE_CTL3_LPI_EN);
+
+	return genphy_c45_ethtool_get_eee(phydev, data);
+}
+
+static int at803x_set_eee(struct phy_device *phydev, struct ethtool_eee *data)
+{
+	struct at803x_priv *priv = phydev->priv;
+	int ret;
+
+	/* If SmartEEE is not enabled, it is expected that tx_lpi_* fields
+	 * are processed by the MAC driver.
+	 */
+	if (priv->flags & AT803X_DISABLE_SMARTEEE)
+		return genphy_c45_ethtool_set_eee(phydev, data);
+
+	/* Changing Tx LPI on/off or Tx LPI timer settings
+	 * do not require link reset.
+	 */
+	ret = at803x_smarteee_config(phydev, data->tx_lpi_enabled,
+				     data->tx_lpi_timer);
+	if (ret)
+		return ret;
+
+	return genphy_c45_ethtool_set_eee(phydev, data);
+}
+
 static int qca83xx_config_init(struct phy_device *phydev)
 {
 	u8 switch_revision;
@@ -2038,6 +2135,8 @@ static struct phy_driver at803x_driver[] = {
 	.set_tunable		= at803x_set_tunable,
 	.cable_test_start	= at803x_cable_test_start,
 	.cable_test_get_status	= at803x_cable_test_get_status,
+	.get_eee		= at803x_get_eee,
+	.set_eee		= at803x_set_eee,
 }, {
 	/* Qualcomm Atheros AR8030 */
 	.phy_id			= ATH8030_PHY_ID,
-- 
2.30.2