From 49011e0c1555dd7a689d0f32fd78c1ecd43e59cd Mon Sep 17 00:00:00 2001 From: Oleksij Rempel Date: Mon, 14 Jun 2021 06:31:25 +0200 Subject: net: phy: micrel: ksz886x/ksz8081: add cabletest support This patch support for cable test for the ksz886x switches and the ksz8081 PHY. The patch was tested on a KSZ8873RLL switch with following results: - port 1: - provides invalid values, thus return -ENOTSUPP (Errata: DS80000830A: "LinkMD does not work on Port 1", http://ww1.microchip.com/downloads/en/DeviceDoc/KSZ8873-Errata-DS80000830A.pdf) - port 2: - can detect distance - can detect open on each wire of pair A (wire 1 and 2) - can detect open only on one wire of pair B (only wire 3) - can detect short between wires of a pair (wires 1 + 2 or 3 + 6) - short between pairs is detected as open. For example short between wires 2 + 3 is detected as open. Signed-off-by: Oleksij Rempel Signed-off-by: David S. Miller --- drivers/net/phy/micrel.c | 180 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 180 insertions(+) (limited to 'drivers/net/phy/micrel.c') diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c index 5ca39ce8db96..4d53886f7d51 100644 --- a/drivers/net/phy/micrel.c +++ b/drivers/net/phy/micrel.c @@ -20,6 +20,7 @@ */ #include +#include #include #include #include @@ -53,6 +54,18 @@ #define KSZPHY_INTCS_STATUS (KSZPHY_INTCS_LINK_DOWN_STATUS |\ KSZPHY_INTCS_LINK_UP_STATUS) +/* LinkMD Control/Status */ +#define KSZ8081_LMD 0x1d +#define KSZ8081_LMD_ENABLE_TEST BIT(15) +#define KSZ8081_LMD_STAT_NORMAL 0 +#define KSZ8081_LMD_STAT_OPEN 1 +#define KSZ8081_LMD_STAT_SHORT 2 +#define KSZ8081_LMD_STAT_FAIL 3 +#define KSZ8081_LMD_STAT_MASK GENMASK(14, 13) +/* Short cable (<10 meter) has been detected by LinkMD */ +#define KSZ8081_LMD_SHORT_INDICATOR BIT(12) +#define KSZ8081_LMD_DELTA_TIME_MASK GENMASK(8, 0) + /* PHY Control 1 */ #define MII_KSZPHY_CTRL_1 0x1e #define KSZ8081_CTRL1_MDIX_STAT BIT(4) @@ -1363,6 +1376,167 @@ static int kszphy_probe(struct phy_device *phydev) return 0; } +static int ksz886x_cable_test_start(struct phy_device *phydev) +{ + if (phydev->dev_flags & MICREL_KSZ8_P1_ERRATA) + return -EOPNOTSUPP; + + /* 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. + * If autoneg is disabled, we should set the speed to 10mbit. + */ + return phy_clear_bits(phydev, MII_BMCR, BMCR_ANENABLE | BMCR_SPEED100); +} + +static int ksz886x_cable_test_result_trans(u16 status) +{ + switch (FIELD_GET(KSZ8081_LMD_STAT_MASK, status)) { + case KSZ8081_LMD_STAT_NORMAL: + return ETHTOOL_A_CABLE_RESULT_CODE_OK; + case KSZ8081_LMD_STAT_SHORT: + return ETHTOOL_A_CABLE_RESULT_CODE_SAME_SHORT; + case KSZ8081_LMD_STAT_OPEN: + return ETHTOOL_A_CABLE_RESULT_CODE_OPEN; + case KSZ8081_LMD_STAT_FAIL: + fallthrough; + default: + return ETHTOOL_A_CABLE_RESULT_CODE_UNSPEC; + } +} + +static bool ksz886x_cable_test_failed(u16 status) +{ + return FIELD_GET(KSZ8081_LMD_STAT_MASK, status) == + KSZ8081_LMD_STAT_FAIL; +} + +static bool ksz886x_cable_test_fault_length_valid(u16 status) +{ + switch (FIELD_GET(KSZ8081_LMD_STAT_MASK, status)) { + case KSZ8081_LMD_STAT_OPEN: + fallthrough; + case KSZ8081_LMD_STAT_SHORT: + return true; + } + return false; +} + +static int ksz886x_cable_test_fault_length(u16 status) +{ + int dt; + + /* According to the data sheet the distance to the fault is + * DELTA_TIME * 0.4 meters. + */ + dt = FIELD_GET(KSZ8081_LMD_DELTA_TIME_MASK, status); + + return (dt * 400) / 10; +} + +static int ksz886x_cable_test_wait_for_completion(struct phy_device *phydev) +{ + int val, ret; + + ret = phy_read_poll_timeout(phydev, KSZ8081_LMD, val, + !(val & KSZ8081_LMD_ENABLE_TEST), + 30000, 100000, true); + + return ret < 0 ? ret : 0; +} + +static int ksz886x_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, + }; + int ret, val, mdix; + + /* There is no way to choice the pair, like we do one ksz9031. + * We can workaround this limitation by using the MDI-X functionality. + */ + if (pair == 0) + mdix = ETH_TP_MDI; + else + mdix = ETH_TP_MDI_X; + + switch (phydev->phy_id & MICREL_PHY_ID_MASK) { + case PHY_ID_KSZ8081: + ret = ksz8081_config_mdix(phydev, mdix); + break; + case PHY_ID_KSZ886X: + ret = ksz886x_config_mdix(phydev, mdix); + break; + default: + ret = -ENODEV; + } + + if (ret) + return ret; + + /* Now we are ready to fire. This command will send a 100ns pulse + * to the pair. + */ + ret = phy_write(phydev, KSZ8081_LMD, KSZ8081_LMD_ENABLE_TEST); + if (ret) + return ret; + + ret = ksz886x_cable_test_wait_for_completion(phydev); + if (ret) + return ret; + + val = phy_read(phydev, KSZ8081_LMD); + if (val < 0) + return val; + + if (ksz886x_cable_test_failed(val)) + return -EAGAIN; + + ret = ethnl_cable_test_result(phydev, ethtool_pair[pair], + ksz886x_cable_test_result_trans(val)); + if (ret) + return ret; + + if (!ksz886x_cable_test_fault_length_valid(val)) + return 0; + + return ethnl_cable_test_fault_length(phydev, ethtool_pair[pair], + ksz886x_cable_test_fault_length(val)); +} + +static int ksz886x_cable_test_get_status(struct phy_device *phydev, + bool *finished) +{ + unsigned long pair_mask = 0x3; + int retries = 20; + int pair, ret; + + *finished = false; + + /* 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 (ret == -EAGAIN) + continue; + if (ret < 0) + return ret; + clear_bit(pair, &pair_mask); + } + /* If link partner is in autonegotiation mode it will send 2ms + * of FLPs with at least 6ms of silence. + * Add 2ms sleep to have better chances to hit this silence. + */ + if (pair_mask) + msleep(2); + } + + *finished = true; + + return ret; +} + static struct phy_driver ksphy_driver[] = { { .phy_id = PHY_ID_KS8737, @@ -1469,6 +1643,7 @@ static struct phy_driver ksphy_driver[] = { .phy_id = PHY_ID_KSZ8081, .name = "Micrel KSZ8081 or KSZ8091", .phy_id_mask = MICREL_PHY_ID_MASK, + .flags = PHY_POLL_CABLE_TEST, /* PHY_BASIC_FEATURES */ .driver_data = &ksz8081_type, .probe = kszphy_probe, @@ -1483,6 +1658,8 @@ static struct phy_driver ksphy_driver[] = { .get_stats = kszphy_get_stats, .suspend = kszphy_suspend, .resume = kszphy_resume, + .cable_test_start = ksz886x_cable_test_start, + .cable_test_get_status = ksz886x_cable_test_get_status, }, { .phy_id = PHY_ID_KSZ8061, .name = "Micrel KSZ8061", @@ -1571,11 +1748,14 @@ static struct phy_driver ksphy_driver[] = { .phy_id_mask = MICREL_PHY_ID_MASK, .name = "Micrel KSZ8851 Ethernet MAC or KSZ886X Switch", /* PHY_BASIC_FEATURES */ + .flags = PHY_POLL_CABLE_TEST, .config_init = kszphy_config_init, .config_aneg = ksz886x_config_aneg, .read_status = ksz886x_read_status, .suspend = genphy_suspend, .resume = genphy_resume, + .cable_test_start = ksz886x_cable_test_start, + .cable_test_get_status = ksz886x_cable_test_get_status, }, { .name = "Micrel KSZ87XX Switch", /* PHY_BASIC_FEATURES */ -- cgit