PPS Generator on Verdin Mini SOM

Hi,

I’m able to run PTP IEEE 1588 on Verdin Mini SOM. Now I need to generate 1 PPS from the SOM. If I understand correctly, There is PPS client support on Torizon/Yocto but not PPS generator. In kernel source, here verdin-imx8mm/kernel-source/drivers/pps/generators, there isa driver for pps_gen_parport.c which is standart Linux kernel support for PPS generator. So there is no pps-gen-gpio support in current Torizon/Yocto.

I found a repo on Github regarding pps-gen-gpio support for Beaglebone Black here. So how do I adapt the repo for iMX8mm. Or is there already a source code for iMX8mm for pps-gen-gpio.

Best regards,
Ibrahim

Hi @ierturk,

I know we have an open issue with NXP related to PPS GPIO client support on the i.MX8 family so I suspect the generators will also have issues but that’s not something we have tested. I’m asking around internally to see if anyone has any ideas but so far I’ve not found anything.

Drew

Hi @drew.tx,

Thanks for the information about the current situation of the IEEE 1588 PPS support. I tried the solutions on the posts [1] and [2] on NXP Forum, but not succeeded so far. May this helps.

However it is not clear how to overlay the pin on device tree. My overlay as follow and I followed the instructions at [3]

#include "../dts-arm64/imx8mm-pinfunc.h"

/dts-v1/;
/plugin/;

// compatible = "toradex,verdin-imx8mm";

&iomuxc {
	pinctrl_gpio8 {
		fsl,pins = <
			MX8MM_IOMUXC_GPIO1_IO09_ENET1_1588_EVENT0_OUT		0x1c4	/* SODIMM 222 */
		>;
	};
};

Is it OK or Do I need to do further pin overlay configuration?

Regards,
Ibrahim

[1] i.MX6 - Best way to enable ENET_1588_EVENT0_OUT PPS events to the pin.
[2] How to get IEEE 1588 1PPS on i.MX6Q?
[3] Device Tree Overlays on Torizon

You can see our ticket with NXP here. There is detail in that post that shows the DTSI changes that we tried but are still having issues with. Hopefully, that will help you get unstuck here.

Drew

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