Raspberry Pi Stack Exchange
Raspberry Pi Stack Exchange

Questions tagged [device-tree]

a Device Tree (DT) is a description of the hardware in a system

source: https://www.raspberrypi.org/documentation/configuration/device-tree.md

74 questions
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is dtoverlay a general linux concept or RPi specific?

With all the raspberry pi hats popping on and off, dtoverlay and /boot/config.txt is a very nice method to quickly tell the kernel that you've got new device tree information. But I've never seen this implemented on any other linux platforms,…
Sittin Hawk
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Emulate Raspberry Pi zero W with Qemu failed due to missing dtb

I am trying to emulate a Raspberry Pi zero W with Qemu based on an image I used on a real Raspberry Pi zero W. The command I am using is: sudo qemu-system-arm \ …
GuillaumeB
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How do I add an i2c device to the device tree?

I am trying to add an mpu 9250 to the device tree of my RPi 3 A+ so that my custom driver's probe function will be called. I have followed this documentation about the Raspberry Pi device tree and this documentation describing the required…
gabson
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SPI enabled in device tree, but I can't use it

I am trying to use SPI interface on Raspberry Pi 1 B (OS: Raspbian July 2017, kerenl 4.9.5). To do this, I am using wiringPi. I confirmed that wiringPi works via gpio readall To load SPI: gpio load spi But this gives me an error: gpio: Unable to…
Jeon
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i2c on a rpi-basic-image created with yocto

I'm attempting to get the i2c bus to work from a raspberry pi image created from yocto. I have looked at other peoples solutions but they are all o do with raspbian or some other flavour of os. My /boot/config.txt looks like this: …
Chris
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Using the Dynamic Device Tree to add Overlays at Run Time

I am working on a couple of ideas for device tree overlays for the RPi 3B+ & 4B. It will be useful in my testing to be able to load and unload overlays without having to reboot each time. As described in The Dynamic Device Tree, the dtoverlay…
Seamus
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dtoverlay=gpio-poweroff not working on raspberry pi 3 B

Problem: I have a Raspi 3B rev: a02082 (Q1 2016 3 Model B 1.2 1 GB (Mfg by Sony)) running raspbian jessie kernel 4.9.35-v7 I want to signal to a power management circuit that filesystems have been un-mounted and now we can remove the power…
saraf
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DeviceTree magic strings

I recently stumbled over the MagPi Essentials Camera. In chapter 7 "Flash photography using an LED" (p.41+), they show how to configure pin BCM17 to act as a flash for the official Raspberry Pi Camera. This totally works for me, but I usually don't…
user49015
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How to build my very own device tree (and if I need to)

Let me preface this by saying I don't know much about device trees. I do know a bit about ATAGs, since I'm working with this operating system that currently only uses ATAGs. I'm modifying the operating system to work on the Raspberry Pi 3s, and…
Priya Bansal
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DS18B20 w1-gpio Device Tree gpiopin NOT = 4

I have a HAT which blocks GPIO4 so I cannot use the default pin for the temperature sensor, but I just cannot get it to work on another pin! I just get lots of 00- instead of 28- in /sys/bus/w1/devices Tried every available free pin using…
MillmoorRon
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How to use i2c_gpio with Raspberry Pi?

I would like to use the i2c_gpio software i2c kernel module because the broadcom hardware i2c does not support I2C_M_NOSTART. How do I do this? I think that in order to do it I need to take the device tree config for i2c_gpio and turn it into a…
Alistair Buxton
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i2c Real Time Clock IC on Raspberry

I am using an industrial device based on a Compute Module Raspberry Pi 3 called Kunbus RevPi Core 3+. The device is shipped with Raspbian and a pre compiled Image but I would like to install an Ubuntu Server 22.04 distro (much better for my…
Stefano Bossi
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i2c_arm bus initialization and device-tree overlay

I've built a Pi1541 HAT, just for fun, and am now playing with the device-tree autoconfiguration in Raspbian. I've made an overlay that autoloads during boot, based on the EEPROM contents, and that overlay defines the five buttons, the LED and the…
Hans Liss
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Enabling SPI card reader in device tree on Raspberry Pi

Good evening, I have MFRC522 card reader. It works well with generic spidev kernel-level driver and high-level python driver. However, as I wanted to learn device trees in linux, I tried to bind kernel-level driver for this chip I found on the…
yomol777
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Re-configure SPI-CS as gpio while using SPI

I am on a raspberry pi 4. Using both SPI's with no need for either chip select. I'm running out of I/O and could really use those. Does anyone know if there is a way to repurpose the SPI chip selects as gpio while still using SPI? Thank you for your…
chrismec
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