[ELDK] Linux DWC OTG Driver - Host mode

[Stefan Roese]

Hi Mark,

On Monday 29 March 2010 21:24:46 Mark Malopy wrote:
> I've been searching through the ELDK archives and I find I'm having the
> same problem with the DWC OTG Driver in Host mode as Felix Radensky
> reported back in April of 09.
> 
> On my setup, I'm using the linux-2.6.31 kernel on a 405ex based platform
> with the OTG controller connected to an ISP1507D also configured for
> host-only operation.
> 
> As with Felix, I've used a DTS from the kilauea platform and confirmed that
> the applicable CONFIG_USB_GADGET_DWC_OTG flags are set and that the
> Makefile for the dwc_otg driver has been set up to use the DWC_HOST_ONLY
> flag.

This shouldn't be needed. On Kilauea and other platforms using this driver 
(Canyonlands 460EX) DWC_HOST_ONLY is not set. This is because we want to be 
able to use the driver in USB host mode and USB device mode. But nevertheless 
it should work if you only need the USB host mode.
 
> As with Felix's original email, I too get debug output that suggests that
> the core is configured for device mode - I've confirmed this by looking at
> the transactions over the ULPI interface (DP_PULLDOWN and DM_PULLDOWN are
> 0) and the GINTSTS register on the Synopsis USB Core (bit31 (CurMod) is
> zero which causes the OTG drivers to think the core is in device mode).

The USB ID pin is used to differentiate between USB host and device mode. On 
Kilauea there is a jumper (J4) to pull this pin down to force the specific USB 
operation mode. IIRC, then your problem also could be related to the used USB 
cable/adapter.

> So, before I start hacking away at the OTG drivers to force the core into
> host mode, has there been any resolution on the OTG drivers since Felix's
> original email regarding driver configuration and/or confirmation that the
> host drivers do work?

How is the ID pin configured in your hardware? Which USB connector do you 
have? Which cable/adapter are you using?

Cheers,
Stefan

--
DENX Software Engineering GmbH,      MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich,  Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-0 Fax: (+49)-8142-66989-80 Email: office at denx.de