Custom device tree iMX7 Colibri YOCTO

Technical Support
, , ,
1

Hello,

We made a custom carrier board for the i.MX7 Colibri based on the Iris board.

  1. Is this file the default device tree for the i.MX7 Colibri ?

  2. How can we recompile the new device tree and integrate it with YOCTO without following this tutorial ?

  3. We are using for example PIN_45 on the module, which GPIO and bank is it ? How can I manage to find easily this information ?

Thank you in advance.

2

Thank you for using our products.

  1. Details about iMX7 Device tree are there - Device Tree Customization | Toradex Developer Center

  2. The best way is to create your own meta-layer. Please see some details here - High performance, low power Embedded Computing Systems | Toradex Developer Center

  3. GPIO Alphanumeric to GPIO Numeric Assignment | Toradex Developer Center

Best regards,
Alex

3

Thank you for your response.

How can I change the device tree by creating a new layer ? I know how to create a layer, but is this accurate for the device tree ? If yes, how ?

Sorry I’m new to this stuff…

Thank for your help

4

hi, what do you mean by creating a layer?

5

I already have created my own meta-layer, incorporating libraries and make them work on my board.
But I don’t know I can do this with the device tree.

6

Hi,

I patch my device trees by creating a .bbappend for the kernel version. I don’t know which one yours is.

In that .bbappend you add the patches for your device trees and that’s it.

Best Regards,

7

Hi,

Thank you for your response.

Are you doing this just like the response here ?

Thank you for your help.

8

Hi,

I haven’t done exactly like that but Option Two: Manual - Kernel Configuration seems like it does the trick.

If you aren’t successful while doing it I can provide you an example.

Regards

9

Hi,

I will be glad if you had one…

Thank you for your help !

10

Hi

Here it is:

My bbappend (applying several patches)

FILESEXTRAPATHS_prepend := "${THISDIR}/linux-toradex-custom:"

SRC_URI += "file://0002-Update-device-trees.patch \
            file://0004-Add-nfc-nxp-pn5xx-driver.patch \
            file://0005-Add-splash-screen-image.patch \
            file://0006-Modify-wireless-driver.patch \
"

COMPATIBLE_MACHINE = "(apalis-imx6|apalis-imx6-custom)"

then in /linux-toradex-custom I add the patches

Here’s an example of the device tree patch. I create new dts files, I don’t really patch the available ones but you can adapt with a patch command

--- /dev/null
+++ b/arch/arm/boot/dts/imx6qdl-apalis-custom.dtsi
@@ -0,0 +1,1264 @@
+/*

(more content here but for example sake it isn’t necessary)

For more info I recommend you to watch Toradex’s Webinars on Yocto Project, they helped me in this regard

11

Thank you very much !
I’ll try this and let you know for progresses !

12

I forgot to mention one thing, before you actually do it and reach a dead end… You must also patch the makefile in the /arch/arm/boot/dts/your-machine-folder so it compiles your customized dts!

Other option is to apply the same .bbappend to the already existent dts.

The approach I mentioned creates a new one.

And don’t forget to add new dts name to the KERNEL_DEVICETREES in local.conf or the machine configuration.

Your best bet in my opinion is to apply the .bbappend as presented but instead of creating a new one, patch the existent dtsi.

In your Linux environment, I recommend you to install Meld, on which you cant put two files side-by-side and it can create a patch for you. You just need to modify the destination headers for something like

 --- a/arch/arm/boot/dts/your-dtsi-name.dtsi
 +++ b/arch/arm/boot/dts/your-dts-name.dtsi

Regards