[maemo-developers] [maemo-developers] examining n800 kernel

[From: Frantisek Dufka]

Larry Battraw wrote:
> On 1/16/07, Frantisek Dufka wrote:
>> Seems to be 2.0, capable of high speed mode (480MBits), chip is TUSB6010
>> by TI. No usb host mode is compiled in the kernel. Usb host mode support
>> was also removed from initfs (usb booting) so this may look bad.
> 
>  Looking at the "shiny brochure"-level documentation for the TUSB6010
> it looks like it has full support for USB-OTG, including a 5V charge
> pump for driving peripheral devices.  Whether or not it's possible to
> write support for it due to available documentation is another matter.


Looks like the support is written in the kernel but simply disabled. I'm 
not familiar with USB to such detail but I guess the problem may be 
whether it is wired in n800 to support OTG mode. Kernel configuration 
looks like this:

| |< > Support for Host-side USB
|
| |<*> Inventra Highspeed Dual Role Controller (TI, ...)
|
| |[*]   TUSB 6010 support
|
| |[*]     TUSB 6010 loopback test support

The 'Inventra Highspeed Dual Role Controller' help says

"Say Y here if your system has a dual role high speed USB 
  controller based on the Mentor Graphics silicon IP.  Then 
   configure options to match your silicon and the board 
    it's being used with, including the USB peripheral role, 
     or the USB host role, or both."

Host-side usb disabled means that host side support for Inventra 
Highspeed Dual Role Controller and all the usb peripherial drivers are 
not built.

So either OTG mode is not possible due to HW in n800 or Nokia has no use 
for it so they made the kernel smaller.

Frantisek