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1// SPDX-License-Identifier: GPL-2.0+2/*3 * open_alliance_helpers.c - OPEN Alliance specific PHY diagnostic helpers4 *5 * This file contains helper functions for implementing advanced diagnostic6 * features as specified by the OPEN Alliance for automotive Ethernet PHYs.7 * These helpers include functionality for Time Delay Reflection (TDR), dynamic8 * channel quality assessment, and other PHY diagnostics.9 *10 * For more information on the specifications, refer to the OPEN Alliance11 * documentation: https://opensig.org/automotive-ethernet-specifications/12 * Currently following specifications are partially or fully implemented:13 * - Advanced diagnostic features for 1000BASE-T1 automotive Ethernet PHYs.14 * TC12 - advanced PHY features.15 * https://opensig.org/wp-content/uploads/2024/03/Advanced_PHY_features_for_automotive_Ethernet_v2.0_fin.pdf16 */17 18#include <linux/bitfield.h>19#include <linux/ethtool_netlink.h>20 21#include "open_alliance_helpers.h"22 23/**24 * oa_1000bt1_get_ethtool_cable_result_code - Convert TDR status to ethtool25 * result code26 * @reg_value: Value read from the TDR register27 *28 * This function takes a register value from the HDD.TDR register and converts29 * the TDR status to the corresponding ethtool cable test result code.30 *31 * Return: The appropriate ethtool result code based on the TDR status32 */33int oa_1000bt1_get_ethtool_cable_result_code(u16 reg_value)34{35 u8 tdr_status = FIELD_GET(OA_1000BT1_HDD_TDR_STATUS_MASK, reg_value);36 u8 dist_val = FIELD_GET(OA_1000BT1_HDD_TDR_DISTANCE_MASK, reg_value);37 38 switch (tdr_status) {39 case OA_1000BT1_HDD_TDR_STATUS_CABLE_OK:40 return ETHTOOL_A_CABLE_RESULT_CODE_OK;41 case OA_1000BT1_HDD_TDR_STATUS_OPEN:42 return ETHTOOL_A_CABLE_RESULT_CODE_OPEN;43 case OA_1000BT1_HDD_TDR_STATUS_SHORT:44 return ETHTOOL_A_CABLE_RESULT_CODE_SAME_SHORT;45 case OA_1000BT1_HDD_TDR_STATUS_NOISE:46 return ETHTOOL_A_CABLE_RESULT_CODE_NOISE;47 default:48 if (dist_val == OA_1000BT1_HDD_TDR_DISTANCE_RESOLUTION_NOT_POSSIBLE)49 return ETHTOOL_A_CABLE_RESULT_CODE_RESOLUTION_NOT_POSSIBLE;50 return ETHTOOL_A_CABLE_RESULT_CODE_UNSPEC;51 }52}53EXPORT_SYMBOL_GPL(oa_1000bt1_get_ethtool_cable_result_code);54 55/**56 * oa_1000bt1_get_tdr_distance - Get distance to the main fault from TDR57 * register value58 * @reg_value: Value read from the TDR register59 *60 * This function takes a register value from the HDD.TDR register and extracts61 * the distance to the main fault detected by the TDR feature. The distance is62 * measured in centimeters and ranges from 0 to 3100 centimeters. If the63 * distance is not available (0x3f), the function returns -ERANGE.64 *65 * Return: The distance to the main fault in centimeters, or -ERANGE if the66 * resolution is not possible.67 */68int oa_1000bt1_get_tdr_distance(u16 reg_value)69{70 u8 dist_val = FIELD_GET(OA_1000BT1_HDD_TDR_DISTANCE_MASK, reg_value);71 72 if (dist_val == OA_1000BT1_HDD_TDR_DISTANCE_RESOLUTION_NOT_POSSIBLE)73 return -ERANGE;74 75 return dist_val * 100;76}77EXPORT_SYMBOL_GPL(oa_1000bt1_get_tdr_distance);78