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SubjectRe: [PATCH v3] usb: dwc3: Add support for VBUS power control


Mike Looijmans <> writes:
> Met vriendelijke groet / kind regards,
> Mike Looijmans
> System Expert
> TOPIC Embedded Products B.V.
> Materiaalweg 4, 5681 RJ Best
> The Netherlands
> T: +31 (0) 499 33 69 69
> E:
> W:
> Please consider the environment before printing this e-mail
> On 27-07-2020 12:23, Mark Brown wrote:
>> On Sun, Jul 26, 2020 at 09:10:39AM +0200, Mike Looijmans wrote:
>>> On 23-07-2020 13:05, Mark Brown wrote:
>>>> Does the device actually support running without power so that's a thing
>>>> that can happen? _get_optional() should only ever be used for supplies
>>>> that may be physically absent.
>>> It's the 5V VBUS power for the USB "plug" that's being controlled here. It
>>> must turned on when the controller is in "host" mode. Some boards arrange
>>> this in hardware through the PHY, and some just don't have any control at
>>> all and have it permanently on or off. On a board where the 5V is controlled
>>> using a GPIO line or an I2C chip, this patch is required to make it work.
>> That sounds like the driver should not be using _get_optional() then.
> Making it mandatory would break most (read: all except Topic's) existing
> boards as they won't have it in their devicetree. I'm perfectly okay with
> that, but others might disagree.

you're perfectly okay with break all existing users of the driver?
That's a bit harsh

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