DTS Needs for PTP on IMX?

[clementLollygag]

Been trying to run ptp4l on my Linux build on an IMXMP with a grandmaster clock on the same network. I can never get the foreign clock to be detected even though I can see with tcpdump that I am receiving PTP multicast messages over ethernet from the expected grandmaster IP address.

Starting to expect a device tree thing and, per most device tree topics, there seems to be minimal information online for PTP-specific device tree needs. Also possible we are missing something in the kernel config file but, for any suggested config options I see online, we already have that option implemented. So wondering if anyone can suggest anything to try in the device tree or kernel config OR point me to a resource for ensuring PTP is able to work in our Linux build.

Thanks for any help in advance!

[clementLollygag]

Update on this - pretty sure this was not a device tree issue but a configuration issue with the IMX8 clock and the test PTP device we were using. On a Wireshark examination, saw that the domain number for PTP was not matching between the 2 devices, causing the IMX8 to never detect a foreign master clock.

[Zhiming_Liu]

Hi

Can you please share the eqos device tree including pinctrl node and hardware design about eqos?

Best Regards
Zhiming

[Zhiming_Liu]

Hi

For dts, you may need add iomux about XXX_XXX_1588_EVENT0_OUT, for example, add MX8MP_IOMUXC_SAI1_RXC__ENET1_1588_EVENT0_OUT in eth pinctrl node. This is decided by your hardware design using which gpio.

MX8MP_IOMUXC_SAI1_RXFS__ENET1_1588_EVENT0_IN	0x100
MX8MP_IOMUXC_SAI1_RXC__ENET1_1588_EVENT0_OUT	0x1c0

For drivers/net/ethernet/freescale/fec_ptp.c, need to use FEC_TMODE_TOGGLE for capturing signal with normal oscilloscope.

Best Regards
Zhiming

[clementLollygag]

Also another note here - I am using the ENET_QOS rather than ENET1. I'm unsure this uses the fec_ptp driver since, according to some example device trees online, the ENET_QOS does not use the fec drivers.

[Zhiming_Liu]

Hi

Only FEC driver use ptp function.

Best Regards
Zhiming

[clementLollygag]

So the nxp,imx8mp-dwmac-eqos driver (driver we link in the device tree) doesn't support PTP/PTP4L? I am pretty confident the ENET EQOS supports IEEE 1588 so this is surprising.

[Zhiming_Liu]

Hi

Sorry, just declear again, the EQOS use drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c, not fec_ptp.c. There is no need to modify stmmac_ptp.c. After setting the dts pinctl about IEEE1588 EVENT OUT, you can try below commands, then you may see pluse.

#  ptp4l -i ethX -p /dev/ptp0 -m -2 &
# T=$(($(date +%s) + 20))
# echo "0 $T 0 1 1" > /sys/class/ptp/ptp0/period

or

echo "0 $(date +%s) 100000000 1 0" > /sys/class/ptp/ptp0/period

Best Regards
Zhiming

[clementLollygag]

Alright good to know it supports it. From the bindings here, I might need to add a ptp route to my device tree...regardless my problem is still not with the GPIO out pin. It is with getting ptp4l to actually see a foreign master clock even though I can see foreign master on wireshark, tcpdump, etc. 

[clementLollygag]

Alright. I am aware of some of the needs to use that event in/out pin. It seems like some people issues with that AFTER ptp4l is able to detect a foreign clock and sync the system clock to a PTP time source. Does that fec_ptp driver need to be linked for ptp4l to see a foreign clock at all? That is my primary issue right now.