[GUIDE] Official Raspberry Touch Display 2

nerd · November 20, 2024, 7:43am

Dear Volumionauts,

The latest arrival from Raspberry Pi yielding 1280×720px resolution is making its way to our ecosystem. Details of the screen are available on Raspberry Pi website:

https://www.raspberrypi.com/documentation/accessories/touch-display-2.html

Based on Ilitec ili9881c DRM driver is not free from its own quirks.

Rotate screen without a desktop

Official documentation references appending to the /boot/cmdline.txt:

video=DSI-1:1280x720@60,rotate=<rotation-value>

Since native panel’s orientation is portrait, using above settings will divide screen into two parts and result into the artefacts burn. The parameters need to be reverted:

video=DSI-1:720x1280@60,rotate=<rotation-value>

DSI port enumeration from the overlay itself is shifted hence:

Physical connector	Parameter
CAM/DISP 0	video=DSI-1:720x1280@60
CAM/DISP 1	video=DSI-2:720x1280@60

NOTICE:
None of the above changes are needed with Volumio-OS. Added for reference only.

Panel litec ili9881c DRM kernel driver

Crafted by Raspbery overlay does not have rotation attribute. As a matter of fact, all screens based on ili9881c follows orientation:

github.com

raspberrypi/linux/blob/57b528e557890f25e010b6bc7356b5a716c79db2/drivers/gpu/drm/panel/panel-ilitek-ili9881c.c#L66


      
          };
          
          struct ili9881c {
          	struct drm_panel	panel;
          	struct mipi_dsi_device	*dsi;
          	const struct ili9881c_desc	*desc;
          
          	struct regulator	*power;
          	struct gpio_desc	*reset;
          
          	enum drm_panel_orientation	orientation;
          };
          
          #define ILI9881C_SWITCH_PAGE_INSTR(_page)	\
          	{					\
          		.op = ILI9881C_SWITCH_PAGE,	\
          		.arg = {			\
          			.page = (_page),	\
          		},				\
          	}

I have reported issue and raised pull request to:

Resource	Link	Status
Raspberry Pi Documentation	Touch Display 2 Rotate screen without a desktop · Issue #3922 · raspberrypi/documentation · GitHub	Merged (Closed)
Raspberry Pi Documentation	Touch Display 2 overlay · Issue #3923 · raspberrypi/documentation · GitHub	Merged (Closed)
PR Kernel	Enable Raspberry Touch 2 rotation with overlay by foonerd · Pull Request #6480 · raspberrypi/linux · GitHub	Merged (Closed)

Reported issues and raised PR are progressing nicely.

Using Official Raspberry Touch Display 2 with Volumio-OS

Until updated pi-kernel is released, Volumio team produces own version of the vc4-kms-dsi-ili9881-7inch overlay.

DT parameter	Action
`sizex`	Sets X resolution (default 720)
`sizey`	Sets Y resolution (default 1280)
`invx`	Invert X coordinates
`invy`	Invert Y coordinates
`swapxy`	Swap X and Y coordinates
`disable_touch`	Disables the touch overlay totally
`rotation`	Set rotation ccw: 0, 90, 180, 270

Volumio Configuration

The download and replace steps below are deprecated with Volumio-OS 3.781 or newer.

~~Until Volumio prepare stable update release containing corrected overlay, follow these steps.~~

~~1. Download vc4-kms-dsi-ili9881-7inch.zip (1.3 KB)~~
~~2. Unzip vc4-kms-dsi-ili9881-7inch.zip~~
~~3. Replace /boot/overlays/vc4-kms-dsi-ili9881-7inch.dtbo with downloaded vc4-kms-dsi-ili9881-7inch.dtbo~~

WARNING - Do not replace /boot/overlays/vc4-kms-dsi-ili9881-7inch.dtbo with downloaded vc4-kms-dsi-ili9881-7inch .zip! Unzip the file first.

Current release based on Debian Buster:
Edit /boot/userconfig.txt and add:

[all]
display_auto_detect=1
# Match your rotation counter clockwise 0, 90, 180, 270 degree
dtoverlay=vc4-kms-dsi-ili9881-7inch,rotation=270

Upcoming release based on Debian Bookworm:
Edit /boot/userconfig.txt and add:

[all]
# Match your rotation counter clockwise 0, 90, 180, 270 degree
dtoverlay=vc4-kms-dsi-ili9881-7inch,rotation=270

Touch Panel plugin
X11 session uses xrand to rotate and this function is already implemented in the plugin. Simply set your rotation within plugin parameters.

NOTICE

The plymouth theme will not rotate and will remain in portrait mode. This is related to fairly outdated plymouth libraries prior rotation being introduced to kernels. There is no point in fixing this. Upcoming Volumio-OS based on Bookworm has currently maintained libraries and plymouth “understands” rotation.

This post will be updated as new changes or discoveries take place.

Kind Regards,

Sir_Yaro · November 17, 2024, 8:53pm

Hi all.

Somehow I couldn’t find any art or post describing how to run this screen with volumio. There are information about “Raspberry Pi Touch Display” v1 out there but nothing (?) about new v2.

So after some tinkering and a LOT of swearing I make it happen and narrow down the process to a few simple steps:

Install “Touch Display” plugin in Volumio plugin manager
At this point, the interface will be displayed only on HDMI output.
If your power supply is able to provide at least 3A (@5V) go to point 2 if not, replace it
Go to /boot/userconfig.txt and add the following:

display_auto_detect=1
[all]
usb_max_current_enable=1

Reboot
In plugin configuration page, rotate screen to the desired orientation (usually 90 degrees)
You might not notice this at first, but after reboot, SSH is disabled. If you need SSHD working as before, go to http://yourvolumioip/dev, where ‘yourvolumioip’ is the actual IP address of your device e.g. 192.168.1.54. Find the SSH section, and click ‘enable’. From now on, your SSH will be permanently enabled.

rottenraisin · November 19, 2024, 4:06pm

Well, that worked! I had to enter “usb_max_…” when running bookworm. Never thought of doing that for this install. Great catch, saved my hair until another day.

nerd · November 21, 2024, 11:05am

Dear Volumionauts,

With Volumio-OS 3.781 there is no need to replace vc4-kms-dsi-ili9881-7inch.dtbo. It is part of the image now.

Thank you @Darmur for making this possible on such short notice.

Kind Regards,