net: phy: marvell: implement cable test for 88E1111

The same implementation is also valid for 88E1145. VCT in 88E1111 is
similar to the 88E609x family. The main difference lies in register
organization and required workarounds.

It utilizes the same fields in registers but requires a simpler
implementation.

Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/marvell.c

@@ -281,6 +281,7 @@
 
 #define MII_VCT_TXPINS			0x1A
 #define MII_VCT_RXPINS			0x1B
+#define MII_VCT_SR			0x1C
 #define MII_VCT_TXPINS_ENVCT		BIT(15)
 #define MII_VCT_TXRXPINS_VCTTST		GENMASK(14, 13)
 #define MII_VCT_TXRXPINS_VCTTST_SHIFT	13
@@ -2623,6 +2624,92 @@ static int m88e3082_vct_cable_test_get_status(struct phy_device *phydev,
 	return 0;
 }
 
+static int m88e1111_vct_cable_test_start(struct phy_device *phydev)
+{
+	int ret;
+
+	ret = marvell_cable_test_start_common(phydev);
+	if (ret)
+		return ret;
+
+	/* It needs some magic workarounds described in VCT manual for this PHY.
+	 */
+	ret = phy_write(phydev, 29, 0x0018);
+	if (ret < 0)
+		return ret;
+
+	ret = phy_write(phydev, 30, 0x00c2);
+	if (ret < 0)
+		return ret;
+
+	ret = phy_write(phydev, 30, 0x00ca);
+	if (ret < 0)
+		return ret;
+
+	ret = phy_write(phydev, 30, 0x00c2);
+	if (ret < 0)
+		return ret;
+
+	ret = phy_write_paged(phydev, MII_MARVELL_COPPER_PAGE, MII_VCT_SR,
+			      MII_VCT_TXPINS_ENVCT);
+	if (ret < 0)
+		return ret;
+
+	ret = phy_write(phydev, 29, 0x0018);
+	if (ret < 0)
+		return ret;
+
+	ret = phy_write(phydev, 30, 0x0042);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static u32 m88e1111_vct_distrfln_2_cm(u8 distrfln)
+{
+	if (distrfln < 36)
+		return 0;
+
+	/* Original function for meters: y = 0.8018x - 28.751 */
+	return (8018 * distrfln - 287510) / 100;
+}
+
+static int m88e1111_vct_cable_test_get_status(struct phy_device *phydev,
+					      bool *finished)
+{
+	u8 vcttst_res, distrfln;
+	int ret, result;
+
+	*finished = false;
+
+	/* Each pair use one page: A-0, B-1, C-2, D-3 */
+	for (u8 i = 0; i < 4; i++) {
+		ret = phy_read_paged(phydev, i, MII_VCT_SR);
+		if (ret < 0)
+			return ret;
+		else if (i == 0 && ret & MII_VCT_TXPINS_ENVCT)
+			return 0;
+
+		distrfln = ret & MII_VCT_TXRXPINS_DISTRFLN;
+		vcttst_res = (ret & MII_VCT_TXRXPINS_VCTTST) >>
+			      MII_VCT_TXRXPINS_VCTTST_SHIFT;
+
+		result = m88e3082_vct_cable_test_report_trans(vcttst_res,
+							      distrfln);
+		ethnl_cable_test_result(phydev, i, result);
+
+		if (distrfln < MII_VCT_TXRXPINS_DISTRFLN_MAX) {
+			u32 cm = m88e1111_vct_distrfln_2_cm(distrfln);
+
+			ethnl_cable_test_fault_length(phydev, i, cm);
+		}
+	}
+
+	*finished = true;
+	return 0;
+}
+
 #ifdef CONFIG_HWMON
 struct marvell_hwmon_ops {
 	int (*config)(struct phy_device *phydev);
@@ -3534,6 +3621,7 @@ static struct phy_driver marvell_drivers[] = {
 		.phy_id_mask = MARVELL_PHY_ID_MASK,
 		.name = "Marvell 88E1111",
 		/* PHY_GBIT_FEATURES */
+		.flags = PHY_POLL_CABLE_TEST,
 		.probe = marvell_probe,
 		.config_init = m88e1111gbe_config_init,
 		.config_aneg = m88e1111_config_aneg,
@@ -3549,6 +3637,8 @@ static struct phy_driver marvell_drivers[] = {
 		.get_stats = marvell_get_stats,
 		.get_tunable = m88e1111_get_tunable,
 		.set_tunable = m88e1111_set_tunable,
+		.cable_test_start = m88e1111_vct_cable_test_start,
+		.cable_test_get_status = m88e1111_vct_cable_test_get_status,
 	},
 	{
 		.phy_id = MARVELL_PHY_ID_88E1111_FINISAR,
@@ -3642,6 +3732,7 @@ static struct phy_driver marvell_drivers[] = {
 		.phy_id_mask = MARVELL_PHY_ID_MASK,
 		.name = "Marvell 88E1145",
 		/* PHY_GBIT_FEATURES */
+		.flags = PHY_POLL_CABLE_TEST,
 		.probe = marvell_probe,
 		.config_init = m88e1145_config_init,
 		.config_aneg = m88e1101_config_aneg,
@@ -3656,6 +3747,8 @@ static struct phy_driver marvell_drivers[] = {
 		.get_stats = marvell_get_stats,
 		.get_tunable = m88e1111_get_tunable,
 		.set_tunable = m88e1111_set_tunable,
+		.cable_test_start = m88e1111_vct_cable_test_start,
+		.cable_test_get_status = m88e1111_vct_cable_test_get_status,
 	},
 	{
 		.phy_id = MARVELL_PHY_ID_88E1149R,