AM4376: Implementing PTP

Viktor Schneigelberger

Part Number: AM4376

Tool/software:

Hello,

Are there any guides or manuals available on how to use PTP on Linux using the AM437x? Especially considering using PHYs with and without IEEE1588v2 support. Any differences in the software approach or hardware setup comparing PHYs with and without IEEE1588v2 support?

Regards,

Viktor

7 months ago

0 Mukul Bhatnagar 7 months ago

TI__Guru* 83715 points

Hello Viktor

Pasting Pekka's previous response to allow follow up queries from you and your customer

Linuxptp does not care are the 1588 timestamps from the xMII interface of the MAC (all TI Processors) or the PHY. I’d argue there is no benefit to timestamp in the PHY, but that gets fairly deep in theory. But also PHY timestamping is supported in Linux. So a properly written PHY driver will support that. A full 1588 PTP stack will not run inside the PHY, it just provides timestamps for a SW PTP state machine.

All the above applies to pretty much all processors and PHY’s regardless of the vendor.

https://linuxptp.sourceforge.net/

some older SDK docs

https://software-dl.ti.com/processor-sdk-linux/esd/docs/05_03_00_07/linux/Industrial_Protocols_PTP.html

0 Pekka Varis 7 months ago in reply to Mukul Bhatnagar

TI__Mastermind 27050 points

All TI Processors and Linux behave the same. Linux kernel has support for HW timestamps (https://docs.kernel.org/networking/timestamping.html) which can come from the xMII interface (this is supported in all Sitara upstream Linux Ethernet drivers), or the PHY. The PHY support would be specific to the PHY drivers that come from the vendor.

Download and install the latest ethernet drivers, latest SDK
At a command prompt type "ethtool -T <eth port>", where <eth port> is the port identifier

If these parameters are present, then Hardware Timestamping is enabled.

SOF_TIMESTAMPING_RAW_HARDWARE
SOF_TIMESTAMPING_TX_HARDWARE
SOF_TIMESTAMPING_RX_HARDWARE

Pekka

0 Dieter Mueller 7 months ago in reply to Pekka Varis

Prodigy 60 points

Dear Pekka,

thanks for your informations. That is very helpful for starting with this.

Sounds easy.

Dieter

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AM4376: Implementing PTP