Questions tagged [device-tree]
A data structure for describing hardware. passed in boot time to kernel
139
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How do I configure device nodes for simple-pm-bus probe?
Inside a soc node I have a watchdog node with a simple-mdf device.
soc {
#address-cells = <2>;
#size-cells = <2>;
compatible = "simple-bus";
...
- 409
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16
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What are pinctrl states and handles in relation to the device tree?
I have a node with the following
mmc0: mmc@11230000 {
compatible = "mediatek,mt8186-mmc", "mediatek,mt8183-mmc";
pinctrl-names = "default",...
- 409
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28
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Will a platform device with waiting for supplier eventually probe?
I have defined a platform device in the Device tree. The following shows the file tree walk for its folder.
/sys/devices/platform/device
/sys/devices/platform/device/uevent
/sys/devices/platform/...
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42
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How do we configure musb-hdrc driver?
I would like to use a USB gadget device (phone) as a host via configfs. After setting up configfs, no gadget is being set up on the host peripheral (phone). The init script executes with the following ...
- 409
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dtb phandle Failed to add to the IOMMU
I have this error :
(XEN) *** LOADING DOMAIN 0 ***
(XEN) Loading d0 kernel from boot module @ 0000000018000000
(XEN) Allocating 1:1 mappings totalling 1024MB for dom0:
(XEN) BANK[0] 0x00000020000000-...
- 61
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2
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70
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uboot kernel and dtb calculation
What is the method to calculate these parameters in uboot ? :
bootm_low=0
bootm_size=7ff00000
fdt_addr_r=0x40000000
fdt_high=0x100000
fdt_size_r=0x400000
fdtcontroladdr=7bc971c0
kernel_addr_r=...
- 61
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23
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Can we automatically label device tree with symbols?
Is it possible to use device tree compiler to automatically label nodes when generating device tree source from device tree binary/source?
I can assign the labels from the symbols to their respectful ...
- 409
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1
answer
87
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unable to boot kernel on A53 (devicetree?)
I am trying to boot a Linux kernel on an A53 cpu (inside a ZU5 from xilinx).
I have two hard. The first is a custom PCB with a ZU5. The second is the ZCU102 SDK with the zu9eg.
Here the boot log :
[ ...
- 61
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28
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tlv320aicx(audio codec) device tree
I'm trying to get solve a kernel message that I'm getting from the tlv320aicx driver. (linux-5.4)
The original error was
Invalid supply voltage(s) AVDD: -22, DVDD: -22
I was able to locate to the ...
- 11
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256
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How to ensure the probing order of SPI bus?
I've an embedded linux system based on a iMX8 CPU. I'm upgrading the yocto-version and therefore the kernel version.
I've two SPI devices on two SPI buses. The device on the second bus has a driver ...
- 49
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1
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81
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Why does linux freezes when trying to access peripherals connected to the lightweight hps-to-fpga bridge (or any bridge)?
I have been working on a Altera DE1-SoC Development Board for 8 months. The system I was working on includes a Cyclone V FPGA chip, particularly the 5CSEMA5F31C6N. It was running an embedded Linux ...
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1
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1
answer
283
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mkdir in configfs not permitted
On my embedded System I enabled the CONFIG_CONFIGFS_FS=y to have access to the configFS. When booted, I mounted it with help of mount -t configfs none /sys/kernel/config. That works like charm:
# ...
- 445
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133
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An rcu_preempt detected stall on Embedded Linux bootup due to USB device tree?
Can anyone point me in the right direction to solve (or at least debug) this rcu_preempt problem I'm experiencing at bootup as shown in the log info below?
I think the problem is related to the device ...
- 11
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0
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37
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run max3421 on device with 3.18 Linux kernel
I need to run USB over SPI on the board which supports only 3.18 kernel. We use MAX3421 because driver for it is in kernel source.
I add to device-tree :
&spi_1 {
status = "ok";
...
- 1
0
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1
answer
239
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How is MTD partition layout detected/parsed in Linux?
I am working on an embedded Linux system, which uses kernel-5.10.24.
There is a NAND FLASH used as storage in system, and it has 4 partitons. When the kernel boots up, there shows 4 partitions as ...
- 367
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1
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263
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Understanding dsi system in device tree
Let's say there is a video bridge like sn65dsi86. It has a driver ti-sn65dsi86.c in kernel source tree. It should be enabled with device trees. There an example for device tree. But it is not complete....
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1
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1
answer
105
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Writing device tree file for ti sn65dsi86
I'm new to device trees, but from all the research I can't find a comprehensive tutorial on writing device trees. If concrete I have an ti sn65dsi86 and I want to connect it to an imx8 chip. Linux has ...
- 83
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1
answer
255
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How do I reference a port in the device tree?
Edit: this is a general question about referencing ports with phandles and the example I posted i.e. my particular case is not that relevant because meanwhile I have observed the same behaviour with ...
- 71
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76
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Does Linux IOMMU subsystem support that "a device have mulitple master interfaces to multiple IOMMU devices"?
We are developing a device that has several ARM MMU-600(SMMU) devices. each SMMU device is connected to multiple masters. We want to use IOMMU subsystem in the Linux kernel to use SMMUs of our device ...
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0
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161
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Can't compile .dts file using dtc
I'm trying to run
sudo make dt_binding_check Documentation/devicetree/bindings/xilinx-xadc.yaml
and I get an error
Error: Documentation/devicetree/bindings/iio/adc/xilinx-xadc.example.dts:22.25-41 ...
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0
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57
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How does Linux device tree know which compatible driver to load?
I am looking at an Android tablet's device tree and it seems it has two touch screen panel by two different manufactors. Both these touch panels have their own drivers.
&spi0 {
#address-cells =...
- 1
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0
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181
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Adding an LCD to Device Tree
I am attempting to define panel-info and display-timings for my SHARP Parallel 24bit LCD Screen within the Device Tree of my Beaglebone Black Debian Image. To do this I am using an overlay .dtbo file. ...
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64
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linux clock tree problems
Do have 2 board with slightly different hardware (same SoC). While kernel/uboot source are same, the dt slightly differs. But I don't touch the overall clock settings.
Nevertheless what systems gives ...
- 115
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1
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261
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Some "disappeared" dm-? files under the /dev directory
Recently I took over a few RHEL systems running with the native DM-multipath, which had been installed & configured by other persons.
My doubts focus on the following questions:
1). Why there ...
- 193
2
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0
answers
402
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How to name a device in the device tree?
I have used a device tree overlay file (dtbo) to add a hardware reference over the i2c-2 node to my device tree. This device is an accelerometer that implements an existing driver that can be found ...
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1
answer
547
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How to implement i2c device in Device Tree?
I currently attempting to implement the mma8452 driver for my mma8451Q accelerometer by adding it to the the Linux Device Tree.
Currently I am taking the route of creating a device tree overlay file (...
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1
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How to load device-tree overlays
I know this is a topic, on which there are several other posts. However none? of them has an accepted answer or even a helpful comment.
But in short, how can load a device tree module (without ...
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Where can I find the device tree source include (.dtsi) files?
I am attempting to review my device tree to learn more about how the usb endpoints are defined, and also just to learn more about device trees. I am currently using a BeagleBone Black image, and I ...
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0
answers
97
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Does a kernel driver get loaded before device tree parsing
When a device tree is getting processed by the kernel on startup, does the kernel load its correct device driver there and then, or it must already be loaded?
Let's take a special I2C device for ...
- 1,121
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1
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669
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Yocto - check if a device tree is enabled in the image
I am currently generating a specialized Yocto image for a Beaglebone device. In the resulting /tmp/deploy/images folder I can see the resulting image, plus alot of device tree files .dtb for different ...
- 1,121
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110
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Use device tree or Kconfig to load a driver
I would like to add and enable a new device in an embedded Linux image.
Is it enough to just specify the information in a device tree file and then the driver for the device will get loaded based on ...
- 1,121
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71
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Investigate Device Tree Problems (with NVIDIA Xavier NX and a custom board)
I have a NVIDIA Xavier NX (aarch64) with a custom board.
It worked well with 4.x kernel and Cboot.
Now after migrating to 5.x kernel and UEFI it hangs on boot with the following error:
"...
- 309
2
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0
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59
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Understand device tree entries and values
I'm new to device tree source editing.
I understand the concept and learned from the bootlin talk:
https://www.youtube.com/watch?v=Nz6aBffv-Ek
I have two .dtsi files:
The first is for 4.X kernel(left) ...
- 309
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517
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i2c device node from device tree is not being probed
I am having trouble troubleshooting my problem where in my i2c pca9546 mux is not being probed by the corresponding driver, i2c-mux-pca954x.c. Here is my device tree node:
&i2c0 {
status = "...
- 11
1
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0
answers
97
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Complete kernel hang after adding bluetooth to system devicetree
I am working right now at adapting yocto distro to run on custom, imx8mm-evk based hardware. I was mostly changing linux devicetree to fit new board needs and everything was fine, but when I added ...
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0
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225
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How does /sys/class/pci_bus correlate the physical PCIe lanes?
On a Dell R7525 I see the following output:
[root@r7525 ~]# ls -al /sys/class/pci_bus/
total 0
drwxr-xr-x. 2 root root 0 May 10 10:38 .
drwxr-xr-x. 62 root root 0 May 10 10:38 ..
lrwxrwxrwx. 1 root ...
- 535
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0
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556
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/aliases: Reference to non-existent node or label "mmc0"
I'm trying to upstream support for u-boot and buildroot for a SoC, I'm merging some changes into master from the vendor's BSP and am having some issues with their dts.
[machinehum@whitebox u-boot]$ ...
- 11
1
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0
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739
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UIO instance of a device-tree subnode
I have the following device-tree node which is auto generated by Xilinx PetaLinux in a proper dtsi file (which cannot be modified):
axi_dma_0: dma@a0000000 {
#dma-cells = <1>;
...
- 747
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196
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About 'unit-address' in Linux devicetree
In Linux devicetree specification v0.3, p. 8, there is one sentence:
The unit-address must match the first address specified in the reg
property of the node. If the node has no reg property, the
@...
- 111
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270
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When is the devicetree parsed to populate the device list on arm64 architecture?
This question comes from my attempts to understand how a built-in platform device driver is initialized at boot time.
I am using an embedded linux distro (Yocto) on a SoC (ARM + FPGA). The device ...
- 149
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1
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103
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gpio_name_to_desc in gpiolib.c in Linux kernel should be externalized?
We have an embedded project, and for our purposes, it seems handy to name all the gpios in the gpio controller device tree stanza using gpio-line-names feature in device tree, mentioned in ...
- 303
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0
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344
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Unable to enable TLV320AIC3104 codec driver /simple sound card for iMx8M with SAI2 BCLK/MCLK provided with external clock
I am trying to access codec driver (TLV320AIC3104) connected to iMX8M over I2C3 and SAI2 lines. The codec clocks bclk is 4096000 and it is provided from an FPGA and its mclk is grounded. iMx8M SOM ...
- 11
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1
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248
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Linux 4.19: apply devicetree overlay on live system
Is it possible to apply a devictree overlay on a live system? We have an embedded system that has some optional hardware. We would like to load the devicetree information after Linux booted.
Reqaon ...
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0
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552
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BeagleBone Black UART 1 config
Recently I compiled my own linux system using kernel 5.10.23, and I made modifications to the device tree in order to activate UART 1 PIN (9-24) and (9-26).
I have /dev/ttyS1 available for R/W ...
- 1
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0
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419
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How to disable TX path of ethernet PHY in embedded linux?
In a yocto-based embedded device I use ethernet only to receive UDP packets. Now I want save energy as the device (as well as the UDP transmitter) is battery powered, and the ethernet PHY (a micrel ...
- 13.4k
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124
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Modified kernel module doesn't load on boot- is the old one being cached somewhere
I'm modifying the qca7000 kernel module slightly by adding some debug messages (qcaspi.ko).
I compile, run depmod then reboot. However my debug messages do not show up on dmesg.
If I rmmod qcaspi then ...
- 145
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0
answers
1k
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Platform driver's probe function isn't called
I am developing a simple platform driver for beaglebone (but currently running on my virtual machine running Ubuntu) that uses device tree, but it doesn't seem like the probe function is being called.
...
- 131
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1
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1k
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Linux, how to add "missing" i2c interface?
I'm working on an embedded project utilizing a Digi ConnectCore 6UL SBC Pro, and I know that dmesg should show me the three I2C interfaces after boot up like:
i2c i2c-0: IMX I2C adapter registered
i2c ...
- 2,049
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0
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592
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Definition and usage of Kernel/Linux DTS file with more than one MIPI DSI Display panel
I actually need some help of defining the kernel/linux DTS file and use it together with the uboot videoargs.
In use is the 5.4.47 uboot and kernel/linux from a NXP imx8m YOCTO project.
In uboot I ...
- 11
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1
answer
21k
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fprintd: The driver encountered a protocol error with the device
I am trying to make work my finger print sensor thinkpad x390 yoga. I installed printfd package using yay. When I try to run fprintd-enroll, I get this error:
Using device /net/reactivated/Fprint/...
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