Am Dienstag, den 07.08.2012, 14:21 -0600 schrieb Stephen Warren:
On 08/07/2012 12:19 PM, Lucas Stach wrote:
This allows for two things:
- VBus GPIO may be used on other ports than the OTG one
- VBus GPIO may be low active if specified by DT
Hmmm. Why would the board have control over whether VBUS is asserted if the port isn't intended to operate in OTG mode?
Perhaps power-saving? In that case, I wonder if representing this as a regulator rather than as a VBUS GPIO would make more sense?
But irrespective of those questions, I'm inclined to think the patch is probably OK.
On Colibri the second USB Port is powered down by default and only powered up if we are really going to use it. And the GPIO does exactly what it tells you from it's name: turn on VBus by triggering the USB power switch. Thinking about a regulator for this in U-Boot is a bit of an overkill, for the Linux kernel this might be another story.