net: phy: micrel: Cable Diag feature for lan8814 phy

Support for Cable Diagnostics in lan8814 phy

Signed-off-by: Divya Koppera <Divya.Koppera@microchip.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20220909083123.30134-1-Divya.Koppera@microchip.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index 7b8c5c8..491a04b 100644 (file)
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -92,6 +92,15 @@
 #define KSZ9x31_LMD_VCT_DATA_HI_PULSE_MASK     GENMASK(1, 0)
 #define KSZ9x31_LMD_VCT_DATA_MASK              GENMASK(7, 0)
 
+#define KSZPHY_WIRE_PAIR_MASK                  0x3
+
+#define LAN8814_CABLE_DIAG                     0x12
+#define LAN8814_CABLE_DIAG_STAT_MASK           GENMASK(9, 8)
+#define LAN8814_CABLE_DIAG_VCT_DATA_MASK       GENMASK(7, 0)
+#define LAN8814_PAIR_BIT_SHIFT                 12
+
+#define LAN8814_WIRE_PAIR_MASK                 0xF
+
 /* Lan8814 general Interrupt control/status reg in GPHY specific block. */
 #define LAN8814_INTC                           0x18
 #define LAN8814_INTS                           0x1B
@@ -257,6 +266,8 @@ static struct kszphy_hw_stat kszphy_hw_stats[] = {
 struct kszphy_type {
        u32 led_mode_reg;
        u16 interrupt_level_mask;
+       u16 cable_diag_reg;
+       unsigned long pair_mask;
        bool has_broadcast_disable;
        bool has_nand_tree_disable;
        bool has_rmii_ref_clk_sel;
@@ -313,6 +324,13 @@ struct kszphy_priv {
 
 static const struct kszphy_type lan8814_type = {
        .led_mode_reg           = ~LAN8814_LED_CTRL_1,
+       .cable_diag_reg         = LAN8814_CABLE_DIAG,
+       .pair_mask              = LAN8814_WIRE_PAIR_MASK,
+};
+
+static const struct kszphy_type ksz886x_type = {
+       .cable_diag_reg         = KSZ8081_LMD,
+       .pair_mask              = KSZPHY_WIRE_PAIR_MASK,
 };
 
 static const struct kszphy_type ksz8021_type = {
@@ -1796,6 +1814,17 @@ static int kszphy_probe(struct phy_device *phydev)
        return 0;
 }
 
+static int lan8814_cable_test_start(struct phy_device *phydev)
+{
+       /* If autoneg is enabled, we won't be able to test cross pair
+        * short. In this case, the PHY will "detect" a link and
+        * confuse the internal state machine - disable auto neg here.
+        * Set the speed to 1000mbit and full duplex.
+        */
+       return phy_modify(phydev, MII_BMCR, BMCR_ANENABLE | BMCR_SPEED100,
+                         BMCR_SPEED1000 | BMCR_FULLDPLX);
+}
+
 static int ksz886x_cable_test_start(struct phy_device *phydev)
 {
        if (phydev->dev_flags & MICREL_KSZ8_P1_ERRATA)
@@ -1809,9 +1838,9 @@ static int ksz886x_cable_test_start(struct phy_device *phydev)
        return phy_clear_bits(phydev, MII_BMCR, BMCR_ANENABLE | BMCR_SPEED100);
 }
 
-static int ksz886x_cable_test_result_trans(u16 status)
+static int ksz886x_cable_test_result_trans(u16 status, u16 mask)
 {
-       switch (FIELD_GET(KSZ8081_LMD_STAT_MASK, status)) {
+       switch (FIELD_GET(mask, status)) {
        case KSZ8081_LMD_STAT_NORMAL:
                return ETHTOOL_A_CABLE_RESULT_CODE_OK;
        case KSZ8081_LMD_STAT_SHORT:
@@ -1825,15 +1854,15 @@ static int ksz886x_cable_test_result_trans(u16 status)
        }
 }
 
-static bool ksz886x_cable_test_failed(u16 status)
+static bool ksz886x_cable_test_failed(u16 status, u16 mask)
 {
-       return FIELD_GET(KSZ8081_LMD_STAT_MASK, status) ==
+       return FIELD_GET(mask, status) ==
                KSZ8081_LMD_STAT_FAIL;
 }
 
-static bool ksz886x_cable_test_fault_length_valid(u16 status)
+static bool ksz886x_cable_test_fault_length_valid(u16 status, u16 mask)
 {
-       switch (FIELD_GET(KSZ8081_LMD_STAT_MASK, status)) {
+       switch (FIELD_GET(mask, status)) {
        case KSZ8081_LMD_STAT_OPEN:
                fallthrough;
        case KSZ8081_LMD_STAT_SHORT:
@@ -1842,29 +1871,79 @@ static bool ksz886x_cable_test_fault_length_valid(u16 status)
        return false;
 }
 
-static int ksz886x_cable_test_fault_length(u16 status)
+static int ksz886x_cable_test_fault_length(struct phy_device *phydev, u16 status, u16 data_mask)
 {
        int dt;
 
        /* According to the data sheet the distance to the fault is
-        * DELTA_TIME * 0.4 meters.
+        * DELTA_TIME * 0.4 meters for ksz phys.
+        * (DELTA_TIME - 22) * 0.8 for lan8814 phy.
         */
-       dt = FIELD_GET(KSZ8081_LMD_DELTA_TIME_MASK, status);
+       dt = FIELD_GET(data_mask, status);
 
-       return (dt * 400) / 10;
+       if ((phydev->phy_id & MICREL_PHY_ID_MASK) == PHY_ID_LAN8814)
+               return ((dt - 22) * 800) / 10;
+       else
+               return (dt * 400) / 10;
 }
 
 static int ksz886x_cable_test_wait_for_completion(struct phy_device *phydev)
 {
+       const struct kszphy_type *type = phydev->drv->driver_data;
        int val, ret;
 
-       ret = phy_read_poll_timeout(phydev, KSZ8081_LMD, val,
+       ret = phy_read_poll_timeout(phydev, type->cable_diag_reg, val,
                                    !(val & KSZ8081_LMD_ENABLE_TEST),
                                    30000, 100000, true);
 
        return ret < 0 ? ret : 0;
 }
 
+static int lan8814_cable_test_one_pair(struct phy_device *phydev, int pair)
+{
+       static const int ethtool_pair[] = { ETHTOOL_A_CABLE_PAIR_A,
+                                           ETHTOOL_A_CABLE_PAIR_B,
+                                           ETHTOOL_A_CABLE_PAIR_C,
+                                           ETHTOOL_A_CABLE_PAIR_D,
+                                         };
+       u32 fault_length;
+       int ret;
+       int val;
+
+       val = KSZ8081_LMD_ENABLE_TEST;
+       val = val | (pair << LAN8814_PAIR_BIT_SHIFT);
+
+       ret = phy_write(phydev, LAN8814_CABLE_DIAG, val);
+       if (ret < 0)
+               return ret;
+
+       ret = ksz886x_cable_test_wait_for_completion(phydev);
+       if (ret)
+               return ret;
+
+       val = phy_read(phydev, LAN8814_CABLE_DIAG);
+       if (val < 0)
+               return val;
+
+       if (ksz886x_cable_test_failed(val, LAN8814_CABLE_DIAG_STAT_MASK))
+               return -EAGAIN;
+
+       ret = ethnl_cable_test_result(phydev, ethtool_pair[pair],
+                                     ksz886x_cable_test_result_trans(val,
+                                                                     LAN8814_CABLE_DIAG_STAT_MASK
+                                                                     ));
+       if (ret)
+               return ret;
+
+       if (!ksz886x_cable_test_fault_length_valid(val, LAN8814_CABLE_DIAG_STAT_MASK))
+               return 0;
+
+       fault_length = ksz886x_cable_test_fault_length(phydev, val,
+                                                      LAN8814_CABLE_DIAG_VCT_DATA_MASK);
+
+       return ethnl_cable_test_fault_length(phydev, ethtool_pair[pair], fault_length);
+}
+
 static int ksz886x_cable_test_one_pair(struct phy_device *phydev, int pair)
 {
        static const int ethtool_pair[] = {
@@ -1872,6 +1951,7 @@ static int ksz886x_cable_test_one_pair(struct phy_device *phydev, int pair)
                ETHTOOL_A_CABLE_PAIR_B,
        };
        int ret, val, mdix;
+       u32 fault_length;
 
        /* There is no way to choice the pair, like we do one ksz9031.
         * We can workaround this limitation by using the MDI-X functionality.
@@ -1910,25 +1990,27 @@ static int ksz886x_cable_test_one_pair(struct phy_device *phydev, int pair)
        if (val < 0)
                return val;
 
-       if (ksz886x_cable_test_failed(val))
+       if (ksz886x_cable_test_failed(val, KSZ8081_LMD_STAT_MASK))
                return -EAGAIN;
 
        ret = ethnl_cable_test_result(phydev, ethtool_pair[pair],
-                                     ksz886x_cable_test_result_trans(val));
+                                     ksz886x_cable_test_result_trans(val, KSZ8081_LMD_STAT_MASK));
        if (ret)
                return ret;
 
-       if (!ksz886x_cable_test_fault_length_valid(val))
+       if (!ksz886x_cable_test_fault_length_valid(val, KSZ8081_LMD_STAT_MASK))
                return 0;
 
-       return ethnl_cable_test_fault_length(phydev, ethtool_pair[pair],
-                                            ksz886x_cable_test_fault_length(val));
+       fault_length = ksz886x_cable_test_fault_length(phydev, val, KSZ8081_LMD_DELTA_TIME_MASK);
+
+       return ethnl_cable_test_fault_length(phydev, ethtool_pair[pair], fault_length);
 }
 
 static int ksz886x_cable_test_get_status(struct phy_device *phydev,
                                         bool *finished)
 {
-       unsigned long pair_mask = 0x3;
+       const struct kszphy_type *type = phydev->drv->driver_data;
+       unsigned long pair_mask = type->pair_mask;
        int retries = 20;
        int pair, ret;
 
@@ -1937,7 +2019,10 @@ static int ksz886x_cable_test_get_status(struct phy_device *phydev,
        /* Try harder if link partner is active */
        while (pair_mask && retries--) {
                for_each_set_bit(pair, &pair_mask, 4) {
-                       ret = ksz886x_cable_test_one_pair(phydev, pair);
+                       if (type->cable_diag_reg == LAN8814_CABLE_DIAG)
+                               ret = lan8814_cable_test_one_pair(phydev, pair);
+                       else
+                               ret = ksz886x_cable_test_one_pair(phydev, pair);
                        if (ret == -EAGAIN)
                                continue;
                        if (ret < 0)
@@ -3111,6 +3196,7 @@ static struct phy_driver ksphy_driver[] = {
        .phy_id         = PHY_ID_LAN8814,
        .phy_id_mask    = MICREL_PHY_ID_MASK,
        .name           = "Microchip INDY Gigabit Quad PHY",
+       .flags          = PHY_POLL_CABLE_TEST,
        .config_init    = lan8814_config_init,
        .driver_data    = &lan8814_type,
        .probe          = lan8814_probe,
@@ -3123,6 +3209,8 @@ static struct phy_driver ksphy_driver[] = {
        .resume         = kszphy_resume,
        .config_intr    = lan8814_config_intr,
        .handle_interrupt = lan8814_handle_interrupt,
+       .cable_test_start       = lan8814_cable_test_start,
+       .cable_test_get_status  = ksz886x_cable_test_get_status,
 }, {
        .phy_id         = PHY_ID_LAN8804,
        .phy_id_mask    = MICREL_PHY_ID_MASK,
@@ -3169,6 +3257,7 @@ static struct phy_driver ksphy_driver[] = {
        .phy_id         = PHY_ID_KSZ886X,
        .phy_id_mask    = MICREL_PHY_ID_MASK,
        .name           = "Micrel KSZ8851 Ethernet MAC or KSZ886X Switch",
+       .driver_data    = &ksz886x_type,
        /* PHY_BASIC_FEATURES */
        .flags          = PHY_POLL_CABLE_TEST,
        .config_init    = kszphy_config_init,