RPI_DSI_Displays

Hardware & Kernel DRM Driver for RPI DSI Displays.
Note: This repository is still under development. Feel free to open issues if you have any questions or suggestions.
Simplified Chinese(简体中文)

Why DSI?

Compared from SPI/DPI panels，DSI panels has taken these advantages:

• High refresh rate(~60fps)
• Easy to wire
• Consume less gpio resources
• Low power consumption

Limitation

Circuit

Due to the circuit design of Raspberry Pi boards, RPi 4b on-board DSI connector only routes out 2 DSI lanes, with a maximum resolution of 720p.
If you want to drive a panel with more than 2 lanes, you may need to consider the compute module or RPi 5.

RPiOS

You must enable DRM first in order to use this driver.
In Raspberry Pi OS releases after 2022-1-28, DRM is enabled by default.
Old releases of RPiOS may not support DRM,so use latest version of RPiOS is recommended.

How to use

*Note: this tutorial and code only keep compatibility with latest RPiOS. If you are using old RPiOS, you are on your own.
Check for kernel headers:

ls /lib/modules/`uname -r`/build

If not, install it:

sudo apt install linux-headers-rpi-v8 # for arm64，armv7 users install linux-headers-rpi-v7

Install make and dtc:

sudo apt install make device-tree-compiler

Clone:

git clone https://github.com/CNflysky/RPI_DSI_Displays
cd RPI_DSI_Displays/src

Compile driver:

make

Move panel-rpi-dsi-displays.ko into /lib/modules:

sudo cp panel-rpi-dsi-displays.ko /lib/modules/`uname -r`/kernel/drivers/gpu/drm/panel
sudo depmod

Compile device tree overlay：

dtc -I dts -O dtb -o vc4-kms-dsi-rpidisp.dtbo vc4-kms-dsi-rpidisp.dts

Move to /boot/firmware/overlays:

sudo cp vc4-kms-dsi-rpidisp.dtbo /boot/firmware/overlays

Edit /boot/firmware/config.txt, add these two lines:

ignore_lcd=1
dtoverlay=vc4-kms-dsi-rpidisp

Reboot.
If you want to get adapters，take a look at adaptersdirectory.
You can view it on OSHWHub too:Link(Chinese version only)

Rotation

vc4-kms-dsi-rpidisp.dts:

panel:panel@0 {
				compatible    = "wlk,w280bf036i";
				status        = "okay";
				reg           = <0>;
				// reset-gpios   = <&gpio 44 0>;
				reset-gpios   = <&gpio 46 0>; // fix me
				backlight = <&panel_backlight>;
				rotation = <0>; // Rotation: [0, 90, 180, 270]
                ...
}

Port your own panel driver

Here
Translated from my blog,may not 100% accurate.

Supported(Or WIP) Panel

Part Number	Diagonal	Resolution	Interface	Connector	TP	Note
W280BF036I	2.8 Inch	VGA(480x640)	DSI 1 Lane	24p Connector	None

Gallery

W280BF036I