Description of problem: I have DS3231 RTC Module that works fine under centos arm arch, but under Fedora arm arch I can't get current date and time from this hardware RTC clock Version-Release number of selected component (if applicable): last updates Steps to Reproduce: 1. connect DS3231 RTC to Raspberry Pi 3 2. add options to file /boot/efi/config.txt dtparam=i2c_arm=on dtoverlay=upstream,i2c-rtc,ds3231 3. create file echo -e "i2c-dev" >> /etc/modules-load.d/i2c.conf 4. dnf -y install i2c-tools && reboot Actual results: dmesg shows hctosys: unable to open rtc device (rtc0) sudo hwclock -r hwclock: Cannot access the Hardware Clock via any known method. hwclock: Use the --verbose option to see the details of our search for an access method. Expected results: hwclock have to get actual time from hardwate RTC Additional info: sudo hwclock -r --verbose hwclock из util-linux 2.33.2 System Time: 1557177406.430509 Trying to open: /dev/rtc0 Trying to open: /dev/rtc Trying to open: /dev/misc/rtc hwclock: Cannot access the Hardware Clock via any known method.
I've fixed my problem. I added new systemd unit cat >> /lib/systemd/system/ebb_hwclock.service [Unit] Description=EBB RTC Service Before=getty.target [Service] Type=oneshot ExecStartPre=/bin/sh -c "/bin/echo ds1307 0x68 > /sys/class/i2c-adapter/i2c-1/new_device" ExecStart=/sbin/hwclock -s -f /dev/rtc1 RemainAfterExit=yes [Install] WantedBy=multi-user.target Then enable new unit and reboot system sudo systemctl enable ebb_hwclock sudo reboot
This is nothing to do with i2c-tools.
There's documentation on how to use HATs with Fedora here: https://fedoraproject.org/w/index.php?title=Architectures/ARM/Raspberry_Pi/HATs The hw clock support was improved in F-34.