Re: [RFC] usb: chipidea: Add minimal support for HSIC interface on i.MX6QDL

[Frieder Schrempf]

Hi Peter,

On 09.10.2018 03:24, Peter Chen wrote:
>   
> > The topic has been discussed before: [1] And there is some implementation in the
> > vendor kernel: [2]
> >
> > It seems like two things need to be done:
> >
> > 1. Switch the pinmux of the strobe signal to use a pullup after
> >     the core has been initialized.
> > 2. Enable HSIC mode and HSIC clock
> >
> > This patch only implements these basics in a minimal approach.
> > You need to have an additional pinmux setting "active" in the dt, that sets the pullup.
> >
> > It was tested with the SMSC LAN9730 USB Ethernet adapter on the iMXceet Solo S
> > board.
>
> Thanks, I should do it earlier, I could not find a suitable board with HSIC support at mainline kernel.
> It is very kind that you could help on it and test function at real board. My suggestion is
> follow all flows in Link [2] since we need to cover suspend/resume and remote wakeup.

It seems like power management and other things in the linux-imx kernel 
are not fully implemented in mainline so there are quite a few differences.

My knowledge of USB, etc. is very limited, so I guess this is currently 
beyond my skills. Can you or someone else provide a patch to get 
started? I could help with testing, reviewing, etc.

Or maybe you can point out what needs to be done in more detail?

Thanks,
Frieder