Bug 243201

Summary: Zynq/Zybo uart reference clock speed is wrong in device tree file.
Product: Base System Reporter: Thomas Skibo <thoma555-bsd>
Component: armAssignee: freebsd-arm (Nobody) <freebsd-arm>
Status: New ---    
Severity: Affects Only Me Keywords: patch
Priority: ---    
Version: CURRENT   
Hardware: arm   
OS: Any   
Attachments:
Description Flags
fix uart reference clock in zynq device tree files none

Description Thomas Skibo 2020-01-09 00:36:15 UTC
Created attachment 210549 [details]
fix uart reference clock in zynq device tree files

The Zybo board uses a 100Mhz reference clock for its uarts but the device tree file indicates it's 50Mhz.  Zybo boots up using whatever speed is set by u-boot but this problem becomes apparent when you attempt to change the uart speed.

The Zedboard uses a 50Mhz clock so it works properly.  But, it seems most Zynq boards use 100Mhz and only the Zedboard uses 50Mhz so my proposed fix is to change the "default" reference clock in zynq-7000.dtsi to 100Mhz and then set Zedboard's ref clock to 50Mhz in zedboard.dts.

Thanks to Milan Obuch for discovering this and pointing it out to me.