Hello,
MUSB PHY on OMAP3EVM Rev>= E uses external Vbus supply to support 500mA of power.We need to program MUSB PHY to use external Vbus for this purpose.
Adding 'extvbus' member in musb_config structure which should be set by all the boards where MUSB interface is using external Vbus supply.
Ajay,
How does the DRVVBUS bit behave on the OMAP3 EVM board on issuing the 'usb reset' command (with musb_cfg.extvbus being set)?
OMAP3EVM doesn't use TPS PHY but it has ISP1507 PHY and uses external Vbus And so it needs extvbus programming (musb_cfg.extvbus =1)in OTG_CTRL register. As for as I know it is not needed for boards using usb PHY on TPS device.
This post has a few more details, but in short it seems that DRVVBUS is automatically set by the TPS chip when doing the bus reset:
Looks like TPS sets the extvbus and so musb_cfg.extvbus doesn't have Any effect.
Ajay
http://lists.denx.de/pipermail/u-boot/2011-June/095221.html
(And indeed, on a board with *no* external vbus, setting musb_cfg.extvbus and reading from a memory stick works just fine.)
I checked the u-boot in the current DVSDK (4.02.00.06) and the git repo for u-boot-ti and they all have the same construct.
Thanks, Orjan
-- Orjan Friberg FlatFrog Laboratories AB