Is it possible to control GigE Ethernet port LEDs of am335x without affecting the functionality?

Sivaraj Sivalingam

Hi,

We have a am335x board with the customized Yocto running on it (kernel version 3.12.10).

The GigE ethernet port(Eth1) has two separate LEDs (LED13, and LED14) on am335x board to show the link status and activity.

We want to control these two LEDs separately without affecting the tx/rx functionality when controlling the LED's.

We are referring to the below datasheet for the GigE phy chip:
ww1.microchip.com/.../KSZ9031RNX.pdf

Would like to know if it is possible, if so, how, to control GigE LEDs of am335x without affecting the functionality?

Thanks,
Sivaraj

over 9 years ago

0 Biser Gatchev-XID over 9 years ago

TI__Guru**** 393215 points

Hi,

On which board are these LEDs, LED13 and LED14 present?

0 Sivaraj Sivalingam over 9 years ago in reply to Biser Gatchev-XID

Prodigy 100 points

It is a am33528zcza60 series based customized prototype board.

0 Biser Gatchev-XID over 9 years ago in reply to Sivaraj Sivalingam

TI__Guru**** 393215 points

So how can I tell where these LEDs are connected? Link status LEDs are normally connected and controlled by the PHY and have nothing to do with AM335X hardware or software.

0 Sivaraj Sivalingam over 9 years ago in reply to Biser Gatchev-XID

Prodigy 100 points

Yes, it is controlled by the GigE PHY chip KSZ9031RNX. The activity LED1 and Link Status LED2 is controlled by the PHY chip only and is not connected to the processor.

So we would like to know is there any way we can control these LEDs through the PHY registers, without disturbing the functionality of tx/rx.

Thanks,
Sivaraj

0 Biser Gatchev-XID over 9 years ago in reply to Sivaraj Sivalingam

TI__Guru**** 393215 points

PHY registers can be read/written from AM335X MDIOUSERACCESS0 Register (section 14.5.10.11 of the AM335X TRM Rev. M). This is done over the MDIO interface.

0 Sivaraj Sivalingam over 9 years ago in reply to Biser Gatchev-XID

Prodigy 100 points

Hi Biser,

Thanks for the response.

We could access the PHY registers through MDIO interface.

We could find registers to control only the LED mode.
But we could not find any registers that can control the LEDs to toggle them on/off.

We could make the LEDs toggle by toggling the "Power-Down" bit of "Basic Control" register, but it will toggle the Ethernet link up and down, which will cause the dataflow to stop.

So we are looking for any other registers through which we can make these two status and activity LEDs toggle on/off, without disturbing the functionality.
Kindly let me know if you have any suggestion or inputs.

Thanks,
Sivaraj

0 Biser Gatchev-XID over 9 years ago in reply to Sivaraj Sivalingam

TI__Guru**** 393215 points

This forum supports the Sitara processor family. It does not support third-party PHY transceivers. You should turn for support to the PHY manufacturer.

0 Sivaraj Sivalingam over 9 years ago in reply to Biser Gatchev-XID

Prodigy 100 points

Sure, thanks a lot for your time answering this.
We will check with the PHY manufacturer.

Thanks,
Sivaraj

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Is it possible to control GigE Ethernet port LEDs of am335x without affecting the functionality?