Re: [PATCH 8/9] usb: phy: am335x: call usb_gen_phy_init()/usb_gen_phy_shutdown() in am335x_init()/am335x_shutdown()

From: Lothar WaÃmann
Date: Tue Jul 22 2014 - 04:06:38 EST


Hi,

Felipe Balbi wrote:
> Hi,,
>
> On Mon, Jul 21, 2014 at 10:03:07AM +0200, Lothar WaÃmann wrote:
> > Hi,
> >
> > > On Fri, Jul 18, 2014 at 11:31:29AM +0200, Lothar WaÃmann wrote:
> > > > This patch makes it possible to use the musb driver with HW that
> > > > requires external regulators or clocks.
> > >
> > > can you provide an example of such HW ? Are you not using the internal
> > > PHYs ?
> > >
> > The Ka-Ro electronics TX48 module uses the mmc0_clk pin as VBUSEN
> > rathern than usb0_drvvbus. This patch makes it possible to use an
> > external regulator to handle the VBUS switch through the 'vcc-supply'
> > property of the underlying generic_phy device.
>
> OK, I get it now. But why would not use usb0_drvvbus ? You could still
> route usb0_drvvbus to the regulator enable pin and the regulator would
> be enabled for you once correct values are written to the IP's mailbox.
>
> I suppose this has something to do with layout constraints ?
>
Yes. The usb0_drvvbus is used for a different purpose.


Lothar WaÃmann
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