On 08/07/2012 02:35 PM, Lucas Stach wrote: > 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.
It's probably fine to do this; the kernel also unconditionally sets up the VBUS GPIO irrespective of USB port mode. > Thinking about a regulator for this in U-Boot is a bit of an overkill, > for the Linux kernel this might be another story. Device tree content isn't supposed to be influence by the consumer; it should be identical irrespective of which bootloader/OS/... is using it. So, in the future I expect this to be reworked to get rid of the vbus-gpio property and replace it with a regulator. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
