Add support for reading Signal Quality Indicator (SQI) and enhanced SQI+ from OATC14 10Base-T1S PHYs. - Introduce MDIO register definitions for DCQ_SQI and DCQ_SQIPLUS. - Add `genphy_c45_oatc14_get_sqi_max()` to return the maximum supported SQI/SQI+ level. - Add `genphy_c45_oatc14_get_sqi()` to return the current SQI or SQI+ value. - Update `include/linux/phy.h` to expose the new APIs. SQI+ capability is read from the Advanced Diagnostic Features Capability register (ADFCAP). If SQI+ is supported, the driver calculates the value from the MSBs of the DCQ_SQIPLUS register; otherwise, it falls back to basic SQI (0-7 levels). These changes allow higher-layer drivers and diagnostic tools to assess link quality more accurately for OATC14 PHYs. Open Alliance TC14 10BASE-T1S Advanced Diagnostic PHY Features Specification ref: https://opensig.org/wp-content/uploads/2025/06/OPEN_Alliance_10BASE-T1S_Advanced_PHY_features_for-automotive_Ethernet_V2.1b.pdf Signed-off-by: Parthiban Veerasooran --- drivers/net/phy/mdio-open-alliance.h | 14 +++++ drivers/net/phy/phy-c45.c | 94 ++++++++++++++++++++++++++++ include/linux/phy.h | 2 + 3 files changed, 110 insertions(+) diff --git a/drivers/net/phy/mdio-open-alliance.h b/drivers/net/phy/mdio-open-alliance.h index 6850a3f0b31e..dcf7b685da5c 100644 --- a/drivers/net/phy/mdio-open-alliance.h +++ b/drivers/net/phy/mdio-open-alliance.h @@ -56,6 +56,8 @@ /* Advanced Diagnostic Features Capability Register*/ #define MDIO_OATC14_ADFCAP 0xcc00 #define OATC14_ADFCAP_HDD_CAPABILITY GENMASK(10, 8) +#define OATC14_ADFCAP_SQIPLUS_CAPABILITY GENMASK(4, 1) +#define OATC14_ADFCAP_SQI_CAPABILITY BIT(0) /* Harness Defect Detection Register */ #define MDIO_OATC14_HDD 0xcc01 @@ -65,6 +67,18 @@ #define OATC14_HDD_VALID BIT(2) #define OATC14_HDD_SHORT_OPEN_STATUS GENMASK(1, 0) +/* Dynamic Channel Quality SQI Register */ +#define MDIO_OATC14_DCQ_SQI 0xcc03 +#define OATC14_DCQ_SQI_UPDATE BIT(15) +#define OATC14_DCQ_SQI_VALUE GENMASK(2, 0) + +/* Dynamic Channel Quality SQI Plus Register */ +#define MDIO_OATC14_DCQ_SQIPLUS 0xcc04 +#define OATC14_DCQ_SQIPLUS_VALUE GENMASK(7, 0) + +/* SQI is supported using 3 bits means 8 levels (0-7) */ +#define OATC14_SQI_MAX_LEVEL 7 + /* Bus Short/Open Status: * 0 0 - no fault; everything is ok. (Default) * 0 1 - detected as an open or missing termination(s) diff --git a/drivers/net/phy/phy-c45.c b/drivers/net/phy/phy-c45.c index e8e5be4684ab..47854c8fb9da 100644 --- a/drivers/net/phy/phy-c45.c +++ b/drivers/net/phy/phy-c45.c @@ -1695,3 +1695,97 @@ int genphy_c45_oatc14_cable_test_start(struct phy_device *phydev) OATC14_HDD_START_CONTROL); } EXPORT_SYMBOL(genphy_c45_oatc14_cable_test_start); + +/** + * genphy_c45_oatc14_get_sqi_max - Get maximum supported SQI or SQI+ level of + OATC14 10Base-T1S PHY + * @phydev: pointer to the PHY device structure + * + * Reads the Signal Quality Indicator (SQI) or enhanced SQI+ capability and + * returns the highest supported level. + * + * Return: + * * Maximum SQI/SQI+ level (≥0) + * * -EOPNOTSUPP if not supported + * * Negative errno on read failure + */ +int genphy_c45_oatc14_get_sqi_max(struct phy_device *phydev) +{ + int bits; + int ret; + + ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, MDIO_OATC14_ADFCAP); + if (ret < 0) + return ret; + + /* SQI+ capability + * 0 - SQI+ is not supported + * X - SQI+ is supported using X bits (0-255 levels) + */ + bits = FIELD_GET(OATC14_ADFCAP_SQIPLUS_CAPABILITY, ret); + if (bits) + /* Max sqi+ level supported: (2 ^ bits) - 1 */ + return BIT(bits) - 1; + + /* SQI capability + * 0 – SQI is not supported + * 1 – SQI is supported (0-7 levels) + */ + if (ret & OATC14_ADFCAP_SQI_CAPABILITY) + return OATC14_SQI_MAX_LEVEL; + + return -EOPNOTSUPP; +} +EXPORT_SYMBOL(genphy_c45_oatc14_get_sqi_max); + +/** + * genphy_c45_oatc14_get_sqi - Get Signal Quality Indicator (SQI) from an OATC14 + 10Base-T1S PHY + * @phydev: pointer to the PHY device structure + * + * Reads the SQI or SQI+ value from an OATC14-compatible 10Base-T1S PHY. If SQI+ + * capability is supported, the function returns the extended SQI+ value; + * otherwise, it returns the basic SQI value. + * + * Return: + * * Positive SQI/SQI+ value on success + * * 0 if SQI update is not available + * * Negative errno on failure + */ +int genphy_c45_oatc14_get_sqi(struct phy_device *phydev) +{ + u8 shift; + int ret; + + /* Read SQI value */ + ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, MDIO_OATC14_DCQ_SQI); + if (ret < 0) + return ret; + + /* Check for SQI update */ + if (!(ret & OATC14_DCQ_SQI_UPDATE)) + return 0; + + /* Read SQI capability */ + ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, MDIO_OATC14_ADFCAP); + if (ret < 0) + return ret; + + /* Calculate and return SQI+ value if supported */ + if (ret & OATC14_ADFCAP_SQIPLUS_CAPABILITY) { + /* SQI+ uses N MSBs out of 8 bits, left-aligned with padding 1's + * Calculate the right-shift needed to isolate the N bits. + */ + shift = 8 - FIELD_GET(OATC14_ADFCAP_SQIPLUS_CAPABILITY, ret); + ret = phy_read_mmd(phydev, MDIO_MMD_VEND2, + MDIO_OATC14_DCQ_SQIPLUS); + if (ret < 0) + return ret; + + return (ret & OATC14_DCQ_SQIPLUS_VALUE) >> shift; + } + + /* Return SQI value if SQI+ capability is not supported */ + return ret & OATC14_DCQ_SQI_VALUE; +} +EXPORT_SYMBOL(genphy_c45_oatc14_get_sqi); diff --git a/include/linux/phy.h b/include/linux/phy.h index bf5457341ca8..a3a8ff099f94 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -2254,6 +2254,8 @@ int genphy_c45_an_config_eee_aneg(struct phy_device *phydev); int genphy_c45_oatc14_cable_test_start(struct phy_device *phydev); int genphy_c45_oatc14_cable_test_get_status(struct phy_device *phydev, bool *finished); +int genphy_c45_oatc14_get_sqi_max(struct phy_device *phydev); +int genphy_c45_oatc14_get_sqi(struct phy_device *phydev); /* The gen10g_* functions are the old Clause 45 stub */ int gen10g_config_aneg(struct phy_device *phydev); -- 2.34.1