How to add EDID for LVDS panel

Prerequisites

• PTN3460 Programming Guide
• EDID config (128 bytes)
• i2c-tools installed

sudo apt update
sudo apt install i2c-tools

Step-by-step procedures

(use EDID 6 and panel G070VW01V0 as example)

On U-Boot

Press any key to stop auto boot, and set matched device tree overlay (dtbo)

• Multi-display (HDMI + LVDS)

The LVDS is always major display that has nothing to do with the specified order.

setenv DISPLAY hdmi.dtbo lvds6.dtbo
saveenv
reset

• LVDS only

setenv DISPLAY lvds6.dtbo
saveenv
reset

On Ubuntu

create the setup script from EDID config

EDIDNEW=6
EDIDBIN=g070vw01v0.bin
SCRIPT=~/set_edid_${EDIDNEW}.sh

REG81=$(printf "0x%02x" 0) # Please refer to the PTN3460 Programming Guide to set correct value
REG84=$(printf "0x%02x" $((2*EDIDNEW + 1)))
REG85=$(printf "0x%02x" $EDIDNEW)
echo -e "REG81:$REG81\nREG84:$REG84\nREG85:$REG85\n"

cat << EOT > $SCRIPT
#!/bin/bash
i2cset -f -y 2 0x20 0x85 $REG85 b

$(
xxd -c 16 -ps $EDIDBIN | 
sed "s/../0x& /g; s/ *$//" | 
for ADDR in `seq 0x00 0x10 0x70`; do
  read 
  echo i2cset -f -y 2 0x20 `printf "0x%02x" $ADDR` $REPLY i
done
)

i2cset -f -y 2 0x20 0x81 $REG81 b
i2cset -f -y 2 0x20 0x84 $REG84 b
i2cset -f -y 2 0x20 0xe8 0x01 0x78 0x45 0x56 i
EOT

chmod +x $SCRIPT

run the script and reboot

sudo $SCRIPT
sudo reboot

Appendix

How to fetch and store EDID config

(use the pre-set EDID 2, panel G070VW01V0, as example)

EDID=2
EDIDBIN=g070vw01v0.bin

sudo i2cset -f -y 2 0x20 0x85 $EDID b

for DA in $(seq 0 0x10 0x70); do
  sudo i2cget -f -y 2 0x20 $DA i 0x10
done | xxd -r -p  > $EDIDBIN