On Wed, Aug 3, 2022 at 4:17 PM Steven A. Falco <email@example.com> wrote:
> I have a Pi4B that is working pretty well with the aarch64 version of Fedora Rawhide, but I have one issue that I haven't been able to find a solution to.
> I have an Adafruit RTC connected via I2C (https://www.adafruit.com/product/3386). If I use the kernel device tree, this device is not found.
> I then tried switching to the firmware device tree via the instructions in https://fedoraproject.org/wiki/Architectures/ARM/Raspberry_Pi/HATs. That works pretty well - I can now add an overlay for the RTC in /boot/efi/config.txt and the RTC is found during boot. dtoverlay=i2c-rtc,pcf8523,addr=0x68
> However, once I've switched to the firmware device tree, I no longer have /dev/vchiq, which means that I can no longer use vcgencmd. Instead, vcgencmd gives me "VCHI initialization failed".
It should be the same as required in Raspbian. Have you checked the
details in /boot/efi/overlays/README? Out of interest what do you use
/dev/vchiq / vcgencmd for?
> Is there any way to get both the RTC and vcgencmd to work? Which device tree would I choose? Do I have to build a custom kernel or is there some other way to enable the RTC with the kernel device tree?
You don't need a custom kernel but you'd need to build your own DT as
obviously anything that is not default on the RPi devices themselves
is optional hence the requirement of overlays.
arm mailing list -- firstname.lastname@example.org
To unsubscribe send an email to email@example.com
Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/
List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines
List Archives: https://firstname.lastname@example.org
Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue