Is there a convenient way to change DDR_SEL and ODT values of the RGMII group of pins without touching the source code? That is from a device tree?
In general to change functions of pins one can easily use the fsl,pins = <PIN_FUNC_ID CONFIG> property.
This is also used to change some bits in the pad configuration register using the CONFIG value.
Unfortunately the DDR_SEL and ODT (among others) register bits in the pad configuration register are read-only and need to be configured using the pad group control registers. How (if at all) can this be done from device tree?
I do not think setting those bits directly from bootloader or from machine platform files is a proper solution. That will be a blocker for upstreaming my board device trees.
My SoC is i.MX6Solo and i.MX6DualLite, RGMII is used to connect a QCA8334 Ethernet switch.
Thanks for any hints.