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

From: Felipe Balbi
Date: Mon Jul 21 2014 - 11:11:59 EST


Hi,,

On Mon, Jul 21, 2014 at 10:03:07AM +0200, Lothar Waßmann wrote:
> Hi,
>
> > On Fri, Jul 18, 2014 at 11:31:29AM +0200, Lothar Waßmann 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 ?

cheers

--
balbi

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