sgjava Posted December 31, 2017 Share Posted December 31, 2017 I've been trying to change the I2C clock frequency on a NanoPi Duo doing the following: cd /boot/dtb sudo cp sun8i-h2-plus-nanopi-duo.dtb sun8i-h2-plus-nanopi-duo.dtb.old sudo dtc -I dtb -O dts -o sun8i-h2-plus-nanopi-duo.dts sun8i-h2-plus-nanopi-duo.dtb sudo nano sun8i-h2-plus-nanopi-duo.dts in i2c@01f02400 section change clock-frequency = <0x186a0> to clock-frequency = <0x30d40> (200 KHz) sudo dtc -I dts -O dtb -o sun8i-h2-plus-nanopi-duo.dtb sun8i-h2-plus-nanopi-duo.dts reboot Looking in armbianEnv.txt I have overlay_prefix=sun8i-h3 and cat /proc/device-tree/model shows FriendlyARM NanoPi DUO. The issue is that no matter what I change clock-frequency to it stays the same i.e. 100 KHz. Either I'm changing the wrong value or I have the wrong template? Link to comment Share on other sites More sharing options...
esc Posted January 2, 2018 Share Posted January 2, 2018 You can ask dtc to scan the tree and produce textual representation of the state. dtc -I fs /sys/firmware/devicetree/base/ If the output from above command includes the change you intended then it must be something else that prevents it from working. 2 Link to comment Share on other sites More sharing options...
martinayotte Posted January 2, 2018 Share Posted January 2, 2018 Try also to set clock-frequency = <0x61a80>, since 200KHz is a non-standard value, maybe any value between 100KHz and 400KHz will fallback to 100KHz. Link to comment Share on other sites More sharing options...
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