topic Re: Forcing i.MX6 USB Host controller to Full-speed in i.MX Processors

Forcing i.MX6 USB Host controller to Full-speed

ganesank — Fri, 09 Dec 2016 10:51:28 GMT

Is it possible to force i.MX6 host-controller to act like Full-speed host controller supporting only full-speed devices downstream in Linux? If so please share the details. We are facing ESD & EFT issues in our product which seems to reduce with full speed USB topology.

We are using Yocto 2.1 - Linux 4.1 with our custom board based on Advantech Q7 i.MX6D module.

Re: Forcing i.MX6 USB Host controller to Full-speed

igorpadykov — Fri, 09 Dec 2016 23:52:42 GMT

Hi Ganesan

please check

https://community.nxp.com/thread/343675

Best regards
igor
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

Re: Forcing i.MX6 USB Host controller to Full-speed

ganesank — Wed, 14 Dec 2016 08:49:29 GMT

Hi Igor,

The discussions are around limiting i.MX6 USB device controller (Chipidea) to Full-speed. I am looking for methods to limit speed of host controller usb_h1 to Full speed if it is possible.

Regards,

Ganesan. K

Re: Forcing i.MX6 USB Host controller to Full-speed

igorpadykov — Wed, 14 Dec 2016 08:53:40 GMT

Hi Ganesan

solution is the same for host

Best regards
igor

Re: Forcing i.MX6 USB Host controller to Full-speed

dhvanil_patel1 — Tue, 07 Feb 2017 09:36:13 GMT

Hi Ganesan,

Have you found out to limit the USB bus speed to full speed?

Igor1z‌,

Can you please help us to limit the USB bus speed to full speed only on i.mx6ul linux

Re: Forcing i.MX6 USB Host controller to Full-speed

ganesank — Fri, 10 Feb 2017 10:24:55 GMT

Hi Patel,

If you are using 4.1.x kernel then it is very straightforward. For forcing host controller to full-speed just add one line maximum-speed = "full-speed"; for the concerned host controller section in your device tree (.dts) file. For example, see my settings for host controller 1 (usbh1)

&usbh1 {
   vbus-supply = <&reg_usb_h1_vbus>;
   reset-gpios = <&gpio7 11 0>;
   maximum-speed = "full-speed";
   status = "okay";
};

This approach works for OTG as well.