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

Orjan Friberg of at flatfrog.com
Tue Jul 5 10:45:48 CEST 2011


On 2010-06-10 07:50, Ajay Kumar Gupta wrote:
> 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)?  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:

   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


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