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Where to modify the rpi5 kernel dts to enable the extra UART in pinout?

Open tonyho opened this issue 11 months ago • 3 comments
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I see there's a cm2712-rpi-5-b.dtb file but I cannot find the corresponding dts file using find -name cm2712-rpi-5-b.dts*.

I want to expose a TTL in pinout from kernel to be used for my Bluetooth controller, for example the GPIO4 and GPIO5 as UART2 RX/TX. But don't know how to enable it.

As in other boards like the amlogic and rockchip based ones, it can be archived by modify the dts file.

Any tips?

tonyho avatar Dec 12 '24 09:12 tonyho

There's no rpi-5 support at the moment. However, all the dts files are located in the kernel tree.

rsglobal avatar Dec 12 '24 09:12 rsglobal

There's no rpi-5 support at the moment. However, all the dts files are located in the kernel tree.

My mistake, I missup the rpi4 and rpi5.

Which one is used for rpi4b?

$find -name bcm2711-rpi-4-b.dts
./aosptree/glodroid/kernel/broadcom/arch/arm64/boot/dts/broadcom/bcm2711-rpi-4-b.dts
./aosptree/glodroid/kernel/broadcom/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
./aosptree/glodroid/bootloader/u-boot/dts/upstream/src/arm64/broadcom/bcm2711-rpi-4-b.dts
./aosptree/glodroid/bootloader/u-boot/dts/upstream/src/arm/broadcom/bcm2711-rpi-4-b.dts
./aosptree/glodroid/bootloader/u-boot/arch/arm/dts/bcm2711-rpi-4-b.dts

And any tips to add the UART? Thanks.

tonyho avatar Dec 12 '24 09:12 tonyho

I thinks I found it: ./aosptree/glodroid/kernel/broadcom/arch/arm/boot/dts/bcm2711-rpi-4-b.dts

tonyho avatar Dec 12 '24 09:12 tonyho