Re: [PATCH v3 2/4] misc: hisi_hikey_usb: change the DT schema

From: Greg Kroah-Hartman
Date: Thu Sep 02 2021 - 09:56:41 EST


On Thu, Sep 02, 2021 at 03:38:20PM +0200, Mauro Carvalho Chehab wrote:
> Em Thu, 2 Sep 2021 15:10:53 +0200
> Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx> escreveu:
>
> > Em Thu, 2 Sep 2021 13:40:28 +0200
> > Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> escreveu:
> >
> > > On Thu, Sep 02, 2021 at 01:28:35PM +0200, Mauro Carvalho Chehab wrote:
> > > > As there's no upstream DT bindings for this driver, let's
> > > > update its DT schema, while it is not too late.
> > >
> > > So this is for 5.15-final?
> >
> > It can either be for 5.15 or 5.16, as there aren't any compatible
> > under arch/ which uses the DT schema there. All patches adding
> > such compatible are on this series. So, whatever version this
> > is applied should be OK.
>
> On a separate note, despite having "hisi_" on this driver's name, there's
> nothing there that is really HiSilicon specific. What this driver does is
> to control an USB HUB integrated inside a DT-based board, doing those
> functions:
>
> - Power on/off the chip;
> - reset the HUB;
> - control its OTG switch;
> - control power on/off for an USB type-C connector;
> - set USB role as host or device.
>
> This is used on both HiKey 960 and HiKey 970 with the following
> topology:
>
> +-----+ +--------+ +---------+
> | SoC | ---> | USB PHY| ---> | USB HUB | ---> USB 3.0
> +-----+ +--------+ +---------+ and type-C ports
>
> Both Kirin 960 and 970 SoCs have a Synapsys IP (DWC 3).
>
> Both HiKey 960 and 970 cards use Richtek RT1711H Type-C Chip Driver
> as part of the USB PHY logic, but they use different USB HUBs:
>
> - HiKey 960 use a Microchip USB5734 HUB
> - HiKey 970 use a TI TUSB8041 HUB
>
> While I'm not sure how generic this driver can be, I'm thinking that
> maybe a future patch could rename it to 'generic-usb-hub' or
> something similar - finding a good name is always the hardest
> part :-)

Try looking at:
https://lore.kernel.org/r/20210813195228.2003500-1-mka@xxxxxxxxxxxx
for another example of this.

thanks,

greg k-h