[help] PHY driver : Unable to find a PHY (unknown ID?)

Thomas Petazzoni thomas.petazzoni at free-electrons.com
Fri Jan 4 06:23:03 EST 2013

Dear Mylene Josserand,

On Fri, 4 Jan 2013 12:03:17 +0100, Mylene Josserand wrote:

> > Good to see some developers from Toulouse using Barebox! I'm close, in
> > Colomiers.
> Yes ! We are neighbour :)

Indeed :)

> Free Electrons, I know you by name. And the kernel sources on your web 
> site help me a lot !

Good to know this is useful.

> > Which board are you targeting?
> It is a "home-made" board with a iMX27.


> Hum, I did not configured it myself. I used a previous configuration of 
> the board which was :
> "
> static struct fec_platform_data fec_info = {
> 	.xcv_type = MII100,
> 	.phy_addr = 1,
> };"
> How can I know which address I need to put ?

Look at chapter "4.11 PHY Address strapping and LED Output Polarity
Selection" of the LAN8700 manual. It says the PHY address is selected
according to the value on pins PHYAD[0:4] during PHY reset. So you
should check your board schematics and see how these pins are wired to
find out what is the PHY address.

Best regards,

Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.

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