CODEWITHSUNDEEP
linux-device-driveru-boot
whh4000
whh4000

Reputation: 955

Reseting a PHY from U-boot

I am building a custom board that is based off of an existing evaluation module for a processor. On the evaluation module there is a MCU that handles most of the boot time configuration. Along with this, the MCU forces a reset on the PHY chips so that the PHY chips can begin communication. On my custom board there will not be an MCU to perform the reset and this the processor must perform the reset.

How would I go about performing the reset from u-boot?

My processor is connected to an SPI -> GPIO expander and this must reset the Phy through the use of SPI. I will not be performing an NFS boot so I do not need the Phys to be accessable from u-boot, but they do need to be reset before the Linux Kernel is booted in order for the kernel drivers to set it up correctly. Any ideas?

Upvotes: 1

Views: 2086

Answers (1)

Vijay Katoch
Vijay Katoch

Reputation: 558

As per MII standards, your PHY chip will have basic mode control register at address 0x00. Look in PHY chip datasheet under 'PHY MDIO register Description'. In U-Boot either phy-chip driver ( example marvell, vitesse etc.) if found, otherwise generic phy-driver will perform the phy reset.

Upvotes: 2

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