forked from mirrors/linux
		
	Introduce helper functions specific to Open Alliance diagnostics, integrating them into the PHY framework. Currently, these helpers are limited to 1000BaseT1 specific TDR functionality. Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Link: https://patch.msgid.link/20240812073046.1728288-2-o.rempel@pengutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
		
			
				
	
	
		
			77 lines
		
	
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			77 lines
		
	
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0+
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/*
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 * open_alliance_helpers.c - OPEN Alliance specific PHY diagnostic helpers
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 *
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 * This file contains helper functions for implementing advanced diagnostic
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 * features as specified by the OPEN Alliance for automotive Ethernet PHYs.
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 * These helpers include functionality for Time Delay Reflection (TDR), dynamic
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 * channel quality assessment, and other PHY diagnostics.
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 *
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 * For more information on the specifications, refer to the OPEN Alliance
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 * documentation: https://opensig.org/automotive-ethernet-specifications/
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 * Currently following specifications are partially or fully implemented:
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 * - Advanced diagnostic features for 1000BASE-T1 automotive Ethernet PHYs.
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 *   TC12 - advanced PHY features.
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 *   https://opensig.org/wp-content/uploads/2024/03/Advanced_PHY_features_for_automotive_Ethernet_v2.0_fin.pdf
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 */
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#include <linux/bitfield.h>
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#include <linux/ethtool_netlink.h>
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#include "open_alliance_helpers.h"
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/**
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 * oa_1000bt1_get_ethtool_cable_result_code - Convert TDR status to ethtool
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 *					      result code
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 * @reg_value: Value read from the TDR register
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 *
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 * This function takes a register value from the HDD.TDR register and converts
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 * the TDR status to the corresponding ethtool cable test result code.
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 *
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 * Return: The appropriate ethtool result code based on the TDR status
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 */
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int oa_1000bt1_get_ethtool_cable_result_code(u16 reg_value)
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{
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	u8 tdr_status = FIELD_GET(OA_1000BT1_HDD_TDR_STATUS_MASK, reg_value);
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	u8 dist_val = FIELD_GET(OA_1000BT1_HDD_TDR_DISTANCE_MASK, reg_value);
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	switch (tdr_status) {
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	case OA_1000BT1_HDD_TDR_STATUS_CABLE_OK:
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		return ETHTOOL_A_CABLE_RESULT_CODE_OK;
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	case OA_1000BT1_HDD_TDR_STATUS_OPEN:
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		return ETHTOOL_A_CABLE_RESULT_CODE_OPEN;
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	case OA_1000BT1_HDD_TDR_STATUS_SHORT:
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		return ETHTOOL_A_CABLE_RESULT_CODE_SAME_SHORT;
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	case OA_1000BT1_HDD_TDR_STATUS_NOISE:
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		return ETHTOOL_A_CABLE_RESULT_CODE_NOISE;
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	default:
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		if (dist_val == OA_1000BT1_HDD_TDR_DISTANCE_RESOLUTION_NOT_POSSIBLE)
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			return ETHTOOL_A_CABLE_RESULT_CODE_RESOLUTION_NOT_POSSIBLE;
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		return ETHTOOL_A_CABLE_RESULT_CODE_UNSPEC;
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	}
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}
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EXPORT_SYMBOL_GPL(oa_1000bt1_get_ethtool_cable_result_code);
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/**
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 * oa_1000bt1_get_tdr_distance - Get distance to the main fault from TDR
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 *				 register value
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 * @reg_value: Value read from the TDR register
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 *
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 * This function takes a register value from the HDD.TDR register and extracts
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 * the distance to the main fault detected by the TDR feature. The distance is
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 * measured in centimeters and ranges from 0 to 3100 centimeters. If the
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 * distance is not available (0x3f), the function returns -ERANGE.
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 *
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 * Return: The distance to the main fault in centimeters, or -ERANGE if the
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 * resolution is not possible.
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 */
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int oa_1000bt1_get_tdr_distance(u16 reg_value)
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{
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	u8 dist_val = FIELD_GET(OA_1000BT1_HDD_TDR_DISTANCE_MASK, reg_value);
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	if (dist_val == OA_1000BT1_HDD_TDR_DISTANCE_RESOLUTION_NOT_POSSIBLE)
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		return -ERANGE;
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	return dist_val * 100;
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}
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EXPORT_SYMBOL_GPL(oa_1000bt1_get_tdr_distance);
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