[U-Boot] [PATCH 2/4 v3] musb: Add Phy programming for usingexternal Vbus

Gupta, Ajay Kumar
2011-07-05T14:16:14Z

Hi,
>On 2011-07-05 13:15, Gupta, Ajay Kumar wrote:
>> 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.
>
>Can you clarify what you mean by "not needed for boards using usb PHY on
>TPS device"?
This comment was more for boards such as Beagle which uses TPS device and
Uses internal charge pump of PHY.

> How does that differ from the ISP1507? From what I'm
>reading, the ISP1507 does have an integrated 5V charge pump. Or is it
>simply a matter of how the board is designed?
Correct. OMAP3EVM (Rev-G) doesn't use internal charge pump but external
Vbus and thus we need to tell the PHY about this using BUS_CTRL.EXTVBUS
Register (Sorry I wrote OTG_CTRL wrongly in previous post)

>
>(On our custom board, we have added an external vbus supply to be able
>to draw > 100 mA.)
So it seems you are using PHY inside TPS659x but external Vbus for which
I think you need to,
1. Explicitly set "OTG_CTRL.D5 = 0" so that PHY doesn't drive 5V.
2. Do not set musb_cfg.extvbus

I have not seen anyone with this option on TPS PHY so not sure of above
Steps would work.

Thanks,
Ajay
>
>Thanks,
>Orjan
>
>--
>Orjan Friberg
>FlatFrog Laboratories AB