How to read XPCS registers from Linux

minersrevolt — Fri, 18 Oct 2024 20:33:16 GMT

Attempting to read the SERDES XPCS registers from Linux following the S32G3 SerDes Subsystem Reference Manual and it does not return valid results. I wrote the following script to attempt this, would appreciate if someone could review this and provide a method if one already exists.

#!/bin/bash # Write to S32G3 SERDES XPCS registers, reference # S32G3 SerDes Subsystem Reference Manual section 5.2 Accessing XPCS registers serdes=$1 # 0 or 1 xpcs=$2 # 0 or 1 reg=$3 write=$4 writeval=$5 debug=1 if [ $# -lt 3 ]; then echo "Read Usage: $0 <serdes 0|1> <xpcs 0|1> <hex register>" echo "Write Usage: $0 <serdes 0|1> <xpcs 0|1> <hex register> 1 <hex value to write>" exit 1 elif [ $# -ne 5 ]; then write=0 fi addr_xpcs_0=0x823FC addr_xpcs_1=0x82BFC serdes0=0x40480000 serdes1=0x44180000 ofs=${reg#0x} ofsleft="0x${ofs:0:4}" # First 4 characters ofsright="0x${ofs:4:2}" # Last 2 characters data1=$ofsleft if [ $xpcs -eq 0 ]; then addr1=$addr_xpcs_0 addr2=$((0x82000 + $ofsright * 4)) elif [ $xpcs -eq 1 ]; then addr1=$addr_xpcs_1 addr2=$((0x82800 + $ofsright * 4)) else echo "Invalid choice for xpcs must be 0|1" exit 1 fi if [ $serdes -eq 0 ]; then addr1=$(($addr1 + $serdes0)) addr2=$(($addr2 + $serdes0)) elif [ $serdes -eq 1 ]; then addr1=$(($addr1 + $serdes1)) addr2=$(($addr2 + $serdes1)) else echo "Serdes must be 0|1" exit 1 fi addr1=$(printf "0x%x" $addr1) addr2=$(printf "0x%x" $addr2) devmem $addr1 32 $data1 if [ $write -eq 1 ]; then echo "writing $writeval to $reg" devmem $addr2 32 $writeval else echo "reading from $reg : $(devmem $addr2)" fi if [ $debug -eq 1 ]; then echo "write $write" echo "writeval $writeval" echo "ofs $ofs" echo "ofsleft $ofsleft" echo "ofsright $ofsright" echo "data1 $data1" echo "addr1 $addr1" echo "addr2 $addr2" fi

Re: How to read XPCS registers from Linux

minersrevolt — Fri, 18 Oct 2024 20:35:16 GMT

Here is the section from the User Guide I implemented,

Re: How to read XPCS registers from Linux

chenyin_h — Tue, 22 Oct 2024 10:26:51 GMT

Hello, @minersrevolt

Thanks for you post.

Well, I do not see any reference code/document that accessing the XPCS registers from user space, may I know if you have referenced the xpcs_read/write functions from the BSP Linux source code?

Chenyin

topic Re: How to read XPCS registers from Linux in S32G

How to read XPCS registers from Linux

Re: How to read XPCS registers from Linux

Re: How to read XPCS registers from Linux