Raspberry Pi 7 Inch Touch Screen on RPi4

[BranwonX]

I am using a raspberry pi 4b 8GB model with the official Raspberry Pi 7 Inch Touch Screen and lakka 4.3, the touch screen does not work, how would i go about enabling touch screen? I already went into lakka settings and turned ON enable touch support and rebooted but still did not work. I could not find info on this anywhere.

[ToKe79]

CONFIG_DRM_PANEL_RASPBERRYPI_TOUCHSCREEN is not enabled in kernel configuration.
I will prepare an image with this option enabled for test on your side.

[BranwonX]

Thanks, and by any chance would you be able to enable this on Lakka 4.3 specifically, if not that is ok i'll still take it in 5.0

[ToKe79]

Image with enabled CONFIG_DRM_PANEL_RASPBERRYPI_TOUCHSCREEN is here:
https://nightly.builds.lakka.tv/members/vudiq/rpi4-touchscreen/

Are there specific reasons why you want to use v4.3?

[BranwonX]

I will test this now, there is no particular reason in why i prefer 4.3 at this time, it works really well for as long as i have used it. I just usually like to wait for a couple of stable updates in a newer release, so that most, if any, bugs would already be fixed before making it my primary OS.

[BranwonX]

the touch screen still did not work, menu cannot be controlled and in game overlays do not respond either. I made sure to turn on Enable Touch Support in the menu.

[ToKe79]

Unfortunately this was the only option that made sense to me, but maybe other options need to enabled as well. If you can get hold of a kernel config from a distro, where the touchscreen works and upload it, I could take a look at the differences. On Ubuntu the config is usually stored in /boot, but on Raspberry it might be different location - it should reside next to the kernel and initrd files.

[gouchi]

It seems that we have to use also dtoverlay=vc4-kms-dsi-7inch ?

Source

[BranwonX]

@gouchi i will test this later today and report back.

[BranwonX]

@ToKe79 i will see if i can find the config within Raspbian OS.

[ToKe79]

I guess kernel is configured properly and really (hopefully) only the overlay is missing.

[BranwonX]

@gouchi dtoverlay=vc4-kms-dsi-7inch or dtoverlay=vc4-kms-dsi-7inch,sizex,sizey still did not allow touch to work, @ToKe79 also not to sure if this matters or not but, the official raspberry screen uses only GPIO pins 3-6 and a ribbon cable to connect from the screen board to the raspberry display ribbon connector, the reason im telling you this is beacue in config.txt there is this line near the bottom that says #dtoverlay=gpio-ir,gpio_pin=18

[ToKe79]

that line is for IR remote - so in same way you shoult add the overlay for the touchscreen.
RPi documentation does not specify, if gpio pins can be selected via the parameters, so I expect if the display instructions say to connect to those PINs, that the overlay is expecting it there.
What I'm afraid is that the touchscreen does not work in KMS, but in Wayland/Xorg. but googling proved me wrong, the driver supports it. Source. They suggest following:

ignore_lcd=1
dtoverlay=vc4-kms-v3d
dtoverlay=vc4-kms-dsi-7inch

Once loaded, run "sudo dtoverlay edt-ft5406" to load the touchscreen driver.

Lakka does not use sudo, you have root out of the box, so I guess running

dtoverlay edt-ft5406

should be enough. In order to do so, you should connect via ssh. If that helps, you may do

echo "dtoverlay edt-ft5406" > /storage/.config/autostart.sh

This will make sure that the command is executed on every boot.

[BranwonX]

i added the 3 lines to config.txt and used ssh to apply dtoverlay edt-ft5406 and i kept getting this error, * Failed to apply overlay '0_edt-ft5406' (kernel)

[gouchi]

@BranwonX I am confused is it working or not ? Because of #1973.

Thank you.

[BranwonX]

The touch does not work on the official 7 inch raspberry pi touchscreen with any version of LAKKA, The #1973 issue was about 2 rows of pixels cut off screen but turned out to be a faulty screen.