picospuch / seeed-linux-dtoverlays

Device Tree Overlays for Seeed boards

seeed-linux-dtoverlays

On embedded systems, the Device Tree helps the kernel understand various peripherals that are connected to the board and how to initialize them. These hardware might be things like LDO regulators, various controllers, GPIO, etc which are generic, but yet needs certain configuration that should not be hard-coded into the kernel. To understand more about device trees I recommend you start with the Raspberry Pi documentation on this topic. There are more links at the end of this article.

LED resource on the board

blue-som gpio-g3
user0-carrier gpio-i1
user1-carrier gpio-h15
user2-carrier gpio-i0

Step 1: make
./test/build

Step 2: add
add uboot_overlay_addr4=/lib/firmware/stm32mp1-seeed-userled-overlay.dtbo to your uEnv.txt.

Overlays:

Step 1: Clone this repo:

git clone https://github.com/Seeed-Studio/seeed-linux-dtoverlays
cd seeed-linux-dtoverlays

Step 2: Install *.dtbo:

make 
#On iMx6ull-NPI
sudo make install_imx6ull
#on RPI
sudo make install_rpi
#On beagleboard
sudo make install_bb

more:

@echo "Targets:"
@echo "  all:                   Build all device tree binaries for all architectures"
@echo "  clean:                 Clean all generated files"
@echo "  install:               Install all generated files (sudo)"
@echo ""
@echo "  all_<PLATFORM>:            Build all device tree binaries for <PLATFORM>"
@echo "  clean_<PLATFORM>:          Clean all generated files for <PLATFORM>"
@echo "  install_<PLATFORM>:        Install all generated files for <PLATFORM> (sudo)"
@echo ""
@echo "  overlays/<PLATFORM>/<DTS>.dtbo   Build a single device tree binary"
@echo ""
@echo "PLATFORMES: $(ALL_PLATFORMES)"

Further Reading

• Device Tree for Dummies: https://elinux.org/images/f/f9/Petazzoni-device-tree-dummies_0.pdf
• Raspberry Pi and the Device Tree: https://www.raspberrypi.org/documentation/configuration/device-tree.md
• Device Tree overlay support in the Linux Kernel: https://www.kernel.org/doc/Documentation/devicetree/overlay-notes.txt
• FDT overlays in U-Boot: https://github.com/u-boot/u-boot/blob/master/doc/README.fdt-overlays

Modules:

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Mainline does not have a kernel module, or there is controversy about a kernel module that does work well. We will also collect them together and put them here. The kernel modules will have the corresponding documentation and detailed instructions。