i.MX8QM USB HSIC support on U-Boot

[philippe_schenk]

Hello

On our board, that is powered by an i.MX8QM SoC, our main USB interface is placed on USB HSIC (pads USB_HSIC0_STROBE and USB_HSIC0_DATA). I now tried to make this USB interface work in U-Boot on NXP's release imx_v2020.04_5.4.24_2.1.0.

I tried with driver model with the following additions to the U-Boot devicetree:

&usbh1 {
	dr_mode = "host";
	vbus-supply = <&reg_usb_host_vbus>;
	status = "okay";
	u-boot,dm-pre-proper;
};

&usbmisc2 {
	status = "okay";
	u-boot,dm-pre-proper;
};

&usbphynop2 {
	status = "okay";
	u-boot,dm-pre-proper;
};

This unfortunately fails and by debugging it I found that the driver is failing at the following line:
https://source.codeaurora.org/external/imx/uboot-imx/tree/drivers/usb/host/ehci-mx6.c?h=imx_v2020.04...

Since i.MX8QM has no real 'reg' register on usbphynop2 (it seems to be a dummy clock) I assume the ehci-mx6.c driver in U-Boot does not support the HSIC usecase for i.MX8QM.

Now my questions:
1. Is my investigation correct that USB HSIC is not supported on i.MX8QM U-Boot?
2. Will this be supported and if yes when?
3. Do you maybe even have a patch for this? (cc: @PeterChen probably ?)

Note1: I was not able to test this on i.MX8QM MEK due to those pads only going to testpoints
Note2: I had the exact same question for the linux-kernel, see: https://community.nxp.com/t5/i-MX-Processors/How-to-interface-USB-HSIC-on-iMX8QM-in-devicetree/m-p/1...

Thanks and Best Regards,

Philippe Schenker

[marcelziswiler]

We meanwhile migrated to NXP BSP L5.4.70_2.3.0 with U-Boot imx_v2020.04_5.4.70_2.3.0. Is HSIC support for the i.MX 8QuadMax available now?

[AldoG]

Hello,

After checking the code, seems that i.MX8QM u-boot code not support HSIC phy.
As for the patch I'm not aware it is one available for this.

Regards,
Aldo.