ODROID C2 RTC module under Arch Linux ARM
How to enable RTC Shield on Arch Linux ARM on ODROID C2
(Based on this Hardkernel wiki)
Install Device Tree Compiler:
# pacman -S dtc
resolving dependencies…
looking for conflicting packages…Packages (1) dtc-1.4.2-1
Total Installed Size: 0.26 MiB
:: Proceed with installation? [Y/n]
(1/1) checking keys in keyring [######################] 100%
(1/1) checking package integrity [######################] 100%
(1/1) loading package files [######################] 100%
(1/1) checking for file conflicts [######################] 100%
(1/1) checking available disk space [######################] 100%
:: Processing package changes…
(1/1) installing dtc [######################] 100%
Enable the RTC module in the DTB file:
# fdtput -t s /boot/dtbs/meson64_odroidc2.dtb /i2c@c1108500/pcf8563@51 status “okay”
Enable the RTC shield in the DTB file at every shutdown / reboot, create a file in /etc/systemd/system like rtc.service:
[Unit]
Description=Enable RTC Shield
DefaultDependencies=no[Service]
Type=oneshot
RemainAfterExit=true
ExecStart=/usr/bin/fdtput -t s /boot/dtbs/meson64_odroidc2.dtb /i2c@c1108500/pcf8563@51 status “okay”[Install]
WantedBy=shutdown.target
Enable the rtc service:
# systemctl enable rtc
Created symlink /etc/systemd/system/shutdown.target.wants/rtc.service -> /etc/systemd/system/rtc.service.
Load the kernel module at boot time:
# echo aml_i2c >> /etc/modules-load.d/aml_i2c.conf
reboot
Confirm RTC time after reboot:
# timedatectl
Local time: Mon 2016-11-14 14:13:37 AST
Universal time: Mon 2016-11-14 11:13:37 UTC
RTC time: Mon 2016-11-14 11:13:37
Time zone: Asia/Qatar (AST, +0300)
Network time on: yes
NTP synchronized: yes
RTC in local TZ: no