My question concerns the instanciation of a Ethernet PHY node on device tree if it is not associate to an Ethernet controller. It’s possible or not ?
According to linux book speaking about device tree, PHY device differs from Ethernet device. So, it could be possible declare PHY device on device tree without using Ethernet parent relationship. But, what is the methology to do it ? indeed, some options (link type,…) comes from Ethernet node instanciation.
Can you help me ?
I can’t answer, that’d take a lot of experimenting. However, a device tree node is passed to a driver, and it is up to that driver what to keep or throw away, and what hardware is needed before the driver can load. So what you need is to know is which driver is associated with that PHY. If it turns out that the PHY driver is also part of another driver, then you might be out of luck if that driver only loads with full hardware. Basically, you need to research the driver for your PHY and find out if it works standalone.
I am not quite sure about your usecase. If you do not want the phy to linked with the ethernet controller, what do you want it to work with? Also, you can contact with PHY vendor first to see if their PHY is able to configure to that.
thank you for your reply.
We have implmented a 88E1512 from Marvel. the idea is to have a MAC link on our board connector to go on our motherboard. So, the Ethernet controller on Xavier NX is associated with the PHY on the SOM, but we have this second PHY (on oour custom board) to have a MAC link.
Indeed, I will cntact marvell to know if their PHy can be piloted with c program (without PHy driver !).