[ELDK] Linux DWC OTG Driver - Host mode

Felix Radensky felix at embedded-sol.com
Wed Mar 31 12:34:19 CEST 2010


Hi Mark,

Stefan Roese wrote:
> Hi Mark,
>
> Again my question from the previous mail: Which USB connector are you using 
> (mini-USB, micro-USB, standard USB...)? And which USB cable/adapter are you 
> using?
>
> Another suggestion is to look at the AMCC Makalu reference design schematics 
> (405EX too). Here a standard USB A-type connector is equipped (they use host 
> mode only here). Perhaps the schematics can reveal some differences to your 
> platform.
>  
>
>   

On our 405EX platform we used ISP1504A PHY configured for host-only mode.
ISP1504A manual requires ID pin to be connected to REG3V3 pin for host-only
or device-only operation. As a result, the value of ID pin was always 1 
on our
platform, while DWC-OTG driver expects value 0 for host mode. On Macalu 
board
mentioned by Stefan, ID pin is connected to the ground, which meets 
driver expectations.

You said you're using ISP1507D PHY, which doesn't seem to have ID pin at 
all, so
I don't know how it works there.

Anyway, I've modified DWC-OTG to work on our platform by rewriting
dwc_otg_is_device_mode() and dwc_otg_is_host_mode() to simply return
0 and 1 respectively. Also, I was loading the driver like this

modprobe dwc_otg otg_cap=2 phy_type=2

Hope this helps.

Felix.
 


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