// SPDX-License-Identifier: GPL-2.0 /* Driver for the Texas Instruments DP83TD510 PHY * Copyright (c) 2022 Pengutronix, Oleksij Rempel */ #include #include #include #include #include #define DP83TD510E_PHY_ID 0x20000181 /* MDIO_MMD_VEND2 registers */ #define DP83TD510E_PHY_STS 0x10 /* Bit 7 - mii_interrupt, active high. Clears on read. * Note: Clearing does not necessarily deactivate IRQ pin if interrupts pending. * This differs from the DP83TD510E datasheet (2020) which states this bit * clears on write 0. */ #define DP83TD510E_STS_MII_INT BIT(7) #define DP83TD510E_LINK_STATUS BIT(0) #define DP83TD510E_GEN_CFG 0x11 #define DP83TD510E_GENCFG_INT_POLARITY BIT(3) #define DP83TD510E_GENCFG_INT_EN BIT(1) #define DP83TD510E_GENCFG_INT_OE BIT(0) #define DP83TD510E_INTERRUPT_REG_1 0x12 #define DP83TD510E_INT1_LINK BIT(13) #define DP83TD510E_INT1_LINK_EN BIT(5) #define DP83TD510E_CTRL 0x1f #define DP83TD510E_CTRL_HW_RESET BIT(15) #define DP83TD510E_CTRL_SW_RESET BIT(14) #define DP83TD510E_AN_STAT_1 0x60c #define DP83TD510E_MASTER_SLAVE_RESOL_FAIL BIT(15) #define DP83TD510E_MSE_DETECT 0xa85 #define DP83TD510_SQI_MAX 7 /* Register values are converted to SNR(dB) as suggested by * "Application Report - DP83TD510E Cable Diagnostics Toolkit": * SNR(dB) = -10 * log10 (VAL/2^17) - 1.76 dB. * SQI ranges are implemented according to "OPEN ALLIANCE - Advanced diagnostic * features for 100BASE-T1 automotive Ethernet PHYs" */ static const u16 dp83td510_mse_sqi_map[] = { 0x0569, /* < 18dB */ 0x044c, /* 18dB =< SNR < 19dB */ 0x0369, /* 19dB =< SNR < 20dB */ 0x02b6, /* 20dB =< SNR < 21dB */ 0x0227, /* 21dB =< SNR < 22dB */ 0x01b6, /* 22dB =< SNR < 23dB */ 0x015b, /* 23dB =< SNR < 24dB */ 0x0000 /* 24dB =< SNR */ }; /* Time Domain Reflectometry (TDR) Functionality of DP83TD510 PHY * * I assume that this PHY is using a variation of Spread Spectrum Time Domain * Reflectometry (SSTDR) rather than the commonly used TDR found in many PHYs. * Here are the following observations which likely confirm this: * - The DP83TD510 PHY transmits a modulated signal of configurable length * (default 16000 µs) instead of a single pulse pattern, which is typical * for traditional TDR. * - The pulse observed on the wire, triggered by the HW RESET register, is not * part of the cable testing process. * * I assume that SSTDR seems to be a logical choice for the 10BaseT1L * environment due to improved noise resistance, making it suitable for * environments with significant electrical noise, such as long 10BaseT1L cable * runs. * * Configuration Variables: * The SSTDR variation used in this PHY involves more configuration variables * that can dramatically affect the functionality and precision of cable * testing. Since most of these configuration options are either not well * documented or documented with minimal details, the following sections * describe my understanding and observations of these variables and their * impact on TDR functionality. * * Timeline: * ,<--cfg_pre_silence_time * | ,<-SSTDR Modulated Transmission * | | ,<--cfg_post_silence_time * | | | ,<--Force Link Mode * |<--'-->|<-------'------->|<--'-->|<--------'------->| * * - cfg_pre_silence_time: Optional silence time before TDR transmission starts. * - SSTDR Modulated Transmission: Transmission duration configured by * cfg_tdr_tx_duration and amplitude configured by cfg_tdr_tx_type. * - cfg_post_silence_time: Silence time after TDR transmission. * - Force Link Mode: If nothing is configured after cfg_post_silence_time, * the PHY continues in force link mode without autonegotiation. */ #define DP83TD510E_TDR_CFG 0x1e #define DP83TD510E_TDR_START BIT(15) #define DP83TD510E_TDR_DONE BIT(1) #define DP83TD510E_TDR_FAIL BIT(0) #define DP83TD510E_TDR_CFG1 0x300 /* cfg_tdr_tx_type: Transmit voltage level for TDR. * 0 = 1V, 1 = 2.4V * Note: Using different voltage levels may not work * in all configuration variations. For example, setting * 2.4V may give different cable length measurements. * Other settings may be needed to make it work properly. */ #define DP83TD510E_TDR_TX_TYPE BIT(12) #define DP83TD510E_TDR_TX_TYPE_1V 0 #define DP83TD510E_TDR_TX_TYPE_2_4V 1 /* cfg_post_silence_time: Time after the TDR sequence. Since we force master mode * for the TDR will proceed with forced link state after this time. For Linux * it is better to set max value to avoid false link state detection. */ #define DP83TD510E_TDR_CFG1_POST_SILENCE_TIME GENMASK(3, 2) #define DP83TD510E_TDR_CFG1_POST_SILENCE_TIME_0MS 0 #define DP83TD510E_TDR_CFG1_POST_SILENCE_TIME_10MS 1 #define DP83TD510E_TDR_CFG1_POST_SILENCE_TIME_100MS 2 #define DP83TD510E_TDR_CFG1_POST_SILENCE_TIME_1000MS 3 /* cfg_pre_silence_time: Time before the TDR sequence. It should be enough to * settle down all pulses and reflections. Since for 10BASE-T1L we have * maximum 2000m cable length, we can set it to 1ms. */ #define DP83TD510E_TDR_CFG1_PRE_SILENCE_TIME GENMASK(1, 0) #define DP83TD510E_TDR_CFG1_PRE_SILENCE_TIME_0MS 0 #define DP83TD510E_TDR_CFG1_PRE_SILENCE_TIME_10MS 1 #define DP83TD510E_TDR_CFG1_PRE_SILENCE_TIME_100MS 2 #define DP83TD510E_TDR_CFG1_PRE_SILENCE_TIME_1000MS 3 #define DP83TD510E_TDR_CFG2 0x301 #define DP83TD510E_TDR_END_TAP_INDEX_1 GENMASK(14, 8) #define DP83TD510E_TDR_END_TAP_INDEX_1_DEF 36 #define DP83TD510E_TDR_START_TAP_INDEX_1 GENMASK(6, 0) #define DP83TD510E_TDR_START_TAP_INDEX_1_DEF 4 #define DP83TD510E_TDR_CFG3 0x302 /* cfg_tdr_tx_duration: Duration of the TDR transmission in microseconds. * This value sets the duration of the modulated signal used for TDR * measurements. * - Default: 16000 µs * - Observation: A minimum duration of 6000 µs is recommended to ensure * accurate detection of cable faults. Durations shorter than 6000 µs may * result in incomplete data, especially for shorter cables (e.g., 20 meters), * leading to false "OK" results. Longer durations (e.g., 6000 µs or more) * provide better accuracy, particularly for detecting open circuits. */ #define DP83TD510E_TDR_TX_DURATION_US GENMASK(15, 0) #define DP83TD510E_TDR_TX_DURATION_US_DEF 16000 #define DP83TD510E_TDR_FAULT_CFG1 0x303 #define DP83TD510E_TDR_FLT_LOC_OFFSET_1 GENMASK(14, 8) #define DP83TD510E_TDR_FLT_LOC_OFFSET_1_DEF 4 #define DP83TD510E_TDR_FLT_INIT_1 GENMASK(7, 0) #define DP83TD510E_TDR_FLT_INIT_1_DEF 62 #define DP83TD510E_TDR_FAULT_STAT 0x30c #define DP83TD510E_TDR_PEAK_DETECT BIT(11) #define DP83TD510E_TDR_PEAK_SIGN BIT(10) #define DP83TD510E_TDR_PEAK_LOCATION GENMASK(9, 0) /* Not documented registers and values but recommended according to * "DP83TD510E Cable Diagnostics Toolkit revC" */ #define DP83TD510E_UNKN_030E 0x30e #define DP83TD510E_030E_VAL 0x2520 static int dp83td510_config_intr(struct phy_device *phydev) { int ret; if (phydev->interrupts == PHY_INTERRUPT_ENABLED) { ret = phy_write_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_INTERRUPT_REG_1, DP83TD510E_INT1_LINK_EN); if (ret) return ret; ret = phy_set_bits_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_GEN_CFG, DP83TD510E_GENCFG_INT_POLARITY | DP83TD510E_GENCFG_INT_EN | DP83TD510E_GENCFG_INT_OE); } else { ret = phy_write_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_INTERRUPT_REG_1, 0x0); if (ret) return ret; ret = phy_clear_bits_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_GEN_CFG, DP83TD510E_GENCFG_INT_EN); if (ret) return ret; } return ret; } static irqreturn_t dp83td510_handle_interrupt(struct phy_device *phydev) { int ret; /* Read the current enabled interrupts */ ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_INTERRUPT_REG_1); if (ret < 0) { phy_error(phydev); return IRQ_NONE; } else if (!(ret & DP83TD510E_INT1_LINK_EN) || !(ret & DP83TD510E_INT1_LINK)) { return IRQ_NONE; } phy_trigger_machine(phydev); return IRQ_HANDLED; } static int dp83td510_read_status(struct phy_device *phydev) { u16 phy_sts; int ret; phydev->speed = SPEED_UNKNOWN; phydev->duplex = DUPLEX_UNKNOWN; phydev->pause = 0; phydev->asym_pause = 0; linkmode_zero(phydev->lp_advertising); phy_sts = phy_read(phydev, DP83TD510E_PHY_STS); phydev->link = !!(phy_sts & DP83TD510E_LINK_STATUS); if (phydev->link) { /* This PHY supports only one link mode: 10BaseT1L_Full */ phydev->duplex = DUPLEX_FULL; phydev->speed = SPEED_10; if (phydev->autoneg == AUTONEG_ENABLE) { ret = genphy_c45_read_lpa(phydev); if (ret) return ret; phy_resolve_aneg_linkmode(phydev); } } if (phydev->autoneg == AUTONEG_ENABLE) { ret = genphy_c45_baset1_read_status(phydev); if (ret < 0) return ret; ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_AN_STAT_1); if (ret < 0) return ret; if (ret & DP83TD510E_MASTER_SLAVE_RESOL_FAIL) phydev->master_slave_state = MASTER_SLAVE_STATE_ERR; } else { return genphy_c45_pma_baset1_read_master_slave(phydev); } return 0; } static int dp83td510_config_aneg(struct phy_device *phydev) { bool changed = false; int ret; ret = genphy_c45_pma_baset1_setup_master_slave(phydev); if (ret < 0) return ret; if (phydev->autoneg == AUTONEG_DISABLE) return genphy_c45_an_disable_aneg(phydev); ret = genphy_c45_an_config_aneg(phydev); if (ret < 0) return ret; if (ret > 0) changed = true; return genphy_c45_check_and_restart_aneg(phydev, changed); } static int dp83td510_get_sqi(struct phy_device *phydev) { int sqi, ret; u16 mse_val; if (!phydev->link) return 0; ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_MSE_DETECT); if (ret < 0) return ret; mse_val = 0xFFFF & ret; for (sqi = 0; sqi < ARRAY_SIZE(dp83td510_mse_sqi_map); sqi++) { if (mse_val >= dp83td510_mse_sqi_map[sqi]) return sqi; } return -EINVAL; } static int dp83td510_get_sqi_max(struct phy_device *phydev) { return DP83TD510_SQI_MAX; } /** * dp83td510_cable_test_start - Start the cable test for the DP83TD510 PHY. * @phydev: Pointer to the phy_device structure. * * This sequence is implemented according to the "Application Note DP83TD510E * Cable Diagnostics Toolkit revC". * * Returns: 0 on success, a negative error code on failure. */ static int dp83td510_cable_test_start(struct phy_device *phydev) { int ret; ret = phy_set_bits_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_CTRL, DP83TD510E_CTRL_HW_RESET); if (ret) return ret; ret = genphy_c45_an_disable_aneg(phydev); if (ret) return ret; /* Force master mode */ ret = phy_set_bits_mmd(phydev, MDIO_MMD_PMAPMD, MDIO_PMA_PMD_BT1_CTRL, MDIO_PMA_PMD_BT1_CTRL_CFG_MST); if (ret) return ret; /* There is no official recommendation for this register, but it is * better to use 1V for TDR since other values seems to be optimized * for this amplitude. Except of amplitude, it is better to configure * pre TDR silence time to 10ms to avoid false reflections (value 0 * seems to be too short, otherwise we need to implement own silence * time). Also, post TDR silence time should be set to 1000ms to avoid * false link state detection, it fits to the polling time of the * PHY framework. The idea is to wait until * dp83td510_cable_test_get_status() will be called and reconfigure * the PHY to the default state within the post silence time window. */ ret = phy_modify_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_TDR_CFG1, DP83TD510E_TDR_TX_TYPE | DP83TD510E_TDR_CFG1_POST_SILENCE_TIME | DP83TD510E_TDR_CFG1_PRE_SILENCE_TIME, DP83TD510E_TDR_TX_TYPE_1V | DP83TD510E_TDR_CFG1_PRE_SILENCE_TIME_10MS | DP83TD510E_TDR_CFG1_POST_SILENCE_TIME_1000MS); if (ret) return ret; ret = phy_write_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_TDR_CFG2, FIELD_PREP(DP83TD510E_TDR_END_TAP_INDEX_1, DP83TD510E_TDR_END_TAP_INDEX_1_DEF) | FIELD_PREP(DP83TD510E_TDR_START_TAP_INDEX_1, DP83TD510E_TDR_START_TAP_INDEX_1_DEF)); if (ret) return ret; ret = phy_write_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_TDR_FAULT_CFG1, FIELD_PREP(DP83TD510E_TDR_FLT_LOC_OFFSET_1, DP83TD510E_TDR_FLT_LOC_OFFSET_1_DEF) | FIELD_PREP(DP83TD510E_TDR_FLT_INIT_1, DP83TD510E_TDR_FLT_INIT_1_DEF)); if (ret) return ret; /* Undocumented register, from the "Application Note DP83TD510E Cable * Diagnostics Toolkit revC". */ ret = phy_write_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_UNKN_030E, DP83TD510E_030E_VAL); if (ret) return ret; ret = phy_write_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_TDR_CFG3, DP83TD510E_TDR_TX_DURATION_US_DEF); if (ret) return ret; ret = phy_set_bits_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_CTRL, DP83TD510E_CTRL_SW_RESET); if (ret) return ret; return phy_set_bits_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_TDR_CFG, DP83TD510E_TDR_START); } /** * dp83td510_cable_test_get_status - Get the status of the cable test for the * DP83TD510 PHY. * @phydev: Pointer to the phy_device structure. * @finished: Pointer to a boolean that indicates whether the test is finished. * * The function sets the @finished flag to true if the test is complete. * * Returns: 0 on success or a negative error code on failure. */ static int dp83td510_cable_test_get_status(struct phy_device *phydev, bool *finished) { int ret, stat; *finished = false; ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_TDR_CFG); if (ret < 0) return ret; if (!(ret & DP83TD510E_TDR_DONE)) return 0; if (!(ret & DP83TD510E_TDR_FAIL)) { int location; ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, DP83TD510E_TDR_FAULT_STAT); if (ret < 0) return ret; if (ret & DP83TD510E_TDR_PEAK_DETECT) { if (ret & DP83TD510E_TDR_PEAK_SIGN) stat = ETHTOOL_A_CABLE_RESULT_CODE_OPEN; else stat = ETHTOOL_A_CABLE_RESULT_CODE_SAME_SHORT; location = FIELD_GET(DP83TD510E_TDR_PEAK_LOCATION, ret) * 100; ethnl_cable_test_fault_length(phydev, ETHTOOL_A_CABLE_PAIR_A, location); } else { stat = ETHTOOL_A_CABLE_RESULT_CODE_OK; } } else { /* Most probably we have active link partner */ stat = ETHTOOL_A_CABLE_RESULT_CODE_UNSPEC; } *finished = true; ethnl_cable_test_result(phydev, ETHTOOL_A_CABLE_PAIR_A, stat); return phy_init_hw(phydev); } static int dp83td510_get_features(struct phy_device *phydev) { /* This PHY can't respond on MDIO bus if no RMII clock is enabled. * In case RMII mode is used (most meaningful mode for this PHY) and * the PHY do not have own XTAL, and CLK providing MAC is not probed, * we won't be able to read all needed ability registers. * So provide it manually. */ linkmode_set_bit(ETHTOOL_LINK_MODE_Autoneg_BIT, phydev->supported); linkmode_set_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT, phydev->supported); linkmode_set_bit(ETHTOOL_LINK_MODE_Pause_BIT, phydev->supported); linkmode_set_bit(ETHTOOL_LINK_MODE_10baseT1L_Full_BIT, phydev->supported); return 0; } static struct phy_driver dp83td510_driver[] = { { PHY_ID_MATCH_MODEL(DP83TD510E_PHY_ID), .name = "TI DP83TD510E", .flags = PHY_POLL_CABLE_TEST, .config_aneg = dp83td510_config_aneg, .read_status = dp83td510_read_status, .get_features = dp83td510_get_features, .config_intr = dp83td510_config_intr, .handle_interrupt = dp83td510_handle_interrupt, .get_sqi = dp83td510_get_sqi, .get_sqi_max = dp83td510_get_sqi_max, .cable_test_start = dp83td510_cable_test_start, .cable_test_get_status = dp83td510_cable_test_get_status, .suspend = genphy_suspend, .resume = genphy_resume, } }; module_phy_driver(dp83td510_driver); static struct mdio_device_id __maybe_unused dp83td510_tbl[] = { { PHY_ID_MATCH_MODEL(DP83TD510E_PHY_ID) }, { } }; MODULE_DEVICE_TABLE(mdio, dp83td510_tbl); MODULE_DESCRIPTION("Texas Instruments DP83TD510E PHY driver"); MODULE_AUTHOR("Oleksij Rempel "); MODULE_LICENSE("GPL v2");