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From:   Peter Chen <peter.chen@nxp.com>
To:     Mike Looijmans <mike.looijmans@topic.nl>
CC:     "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
        "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
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Subject: Re: [PATCH] usb/phy-generic: Add support for OTG VBUS supply control
Thread-Topic: [PATCH] usb/phy-generic: Add support for OTG VBUS supply control
Thread-Index: AQHWM23eFY1+Pfs1gUaTviqfbn5UWqi9XTqAgAE1OoCAABn7AA==
Date:   Fri, 29 May 2020 07:20:14 +0000
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On 20-05-29 07:47:37, Mike Looijmans wrote:
>=20
> Met vriendelijke groet / kind regards,
>=20
> Mike Looijmans
> System Expert
>=20
>=20
> TOPIC Embedded Products B.V.
> Materiaalweg 4, 5681 RJ Best
> The Netherlands
>=20
> T: +31 (0) 499 33 69 69
> E: mike.looijmans@topicproducts.com
> W: https://eur01.safelinks.protection.outlook.com/?url=3Dhttp%3A%2F%2Fwww=
.topicproducts.com%2F&amp;data=3D02%7C01%7Cpeter.chen%40nxp.com%7Cc8a5e33bb=
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>=20
> Please consider the environment before printing this e-mail
> On 28-05-2020 13:20, Peter Chen wrote:
> > On 20-05-26 16:50:51, Mike Looijmans wrote:
> > > This enables support for VBUS on boards where the power is supplied
> > > by a regulator. The regulator is enabled when the USB port enters
> > > HOST mode.
> > >=20
> > Why you don't do this at your host controller driver?
>=20
> That was my first thought too, but it made more sense to do it here. It's
> about how things are connected on the board, and not about the controller=
.
> Also makes for a consistent devicetree when using different SOCs on the s=
ame
> carrier board.

A standard interface is: port_power for hc_driver, but seems the xHCI
doesn't implement it.

>=20
> I already needed this driver to properly reset the USB phy, which the
> controller driver also did not do. So it made sense to add the vbus power
> control to this driver too.
>=20
> If you have a strong preference for the controller driver, I can move thi=
s
> to the DWC3 driver which happens to be the controller for the latest batc=
h
> of SOMs.
>=20

You may ask Mathias or Felipe for comments where is suitable for vbus
regulator.

> > > +
> > >   	nop->dev		=3D dev;
> > >   	nop->phy.dev		=3D nop->dev;
> > >   	nop->phy.label		=3D "nop-xceiv";
> > > @@ -278,6 +319,7 @@ int usb_phy_gen_create_phy(struct device *dev, st=
ruct usb_phy_generic *nop)
> > >   	nop->phy.otg->usb_phy		=3D &nop->phy;
> > >   	nop->phy.otg->set_host		=3D nop_set_host;
> > >   	nop->phy.otg->set_peripheral	=3D nop_set_peripheral;
> > > +	nop->phy.otg->set_vbus		=3D nop_set_vbus;

OTG is dead, even USB-IF has refused OTG test since 2019-09, you may
avoid to use OTG structure.

Peter


> > >   	return 0;
> > >   }
> > > diff --git a/drivers/usb/phy/phy-generic.h b/drivers/usb/phy/phy-gene=
ric.h
> > > index 7ee80211a688..a3663639ea1e 100644
> > > --- a/drivers/usb/phy/phy-generic.h
> > > +++ b/drivers/usb/phy/phy-generic.h
> > > @@ -14,7 +14,9 @@ struct usb_phy_generic {
> > >   	struct gpio_desc *gpiod_reset;
> > >   	struct gpio_desc *gpiod_vbus;
> > >   	struct regulator *vbus_draw;
> > > +	struct regulator *vbus_reg;
> > >   	bool vbus_draw_enabled;
> > > +	bool vbus_reg_enabled;
> > >   	unsigned long mA;
> > >   	unsigned int vbus;
> > >   };
> > > --=20
> > > 2.17.1
> > >=20
>=20
> --=20
> Mike Looijmans
>=20

--=20

Thanks,
Peter Chen=