linux-kernel - Re: [RESEND PATCH v2 7/7] usb: xhci: plat: add vbus regulator control

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Message-ID: <87oa8vmjqg.fsf@intel.com>
Date:	Wed, 27 Apr 2016 13:25:27 +0300
From:	Felipe Balbi <felipe.balbi@...ux.intel.com>
To:	Mark Brown <broonie@...nel.org>
Cc:	Jisheng Zhang <jszhang@...vell.com>, mathias.nyman@...ux.intel.com,
	gregkh@...uxfoundation.org, linux-usb@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	yendapally.reddy@...adcom.com
Subject: Re: [RESEND PATCH v2 7/7] usb: xhci: plat: add vbus regulator control


Hi,

Mark Brown <broonie@...nel.org> writes:
> On Wed, Apr 27, 2016 at 08:37:20AM +0300, Felipe Balbi wrote:
>> Jisheng Zhang <jszhang@...vell.com> writes:
>
>> > +	vbus = devm_regulator_get(&pdev->dev, "vbus");
>
>> devm_regulator_get_optional() ??
>
> Does USB work without a VBUS?  Unless the answer is yes then I'd expect

<joke> it can, just source VBUS from a lab power supply </joke>

> this to be just a normal regulator_get().

jokes aside, this regulator is optional because not all platforms
require a SW controlled regulator, no ? Will normal regulator_get() give
us a dummy regulator in case it's not listed in DT/ACPI ?

-- 
balbi

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