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Warp7 USB-OTG

arre

Hi,

 

  • Using the Warp7 USB OTG port in OTG mode: The port is not supplying 5V power when the board is fed from the battery, although this seems forseen in the schematic
    • Is it possible a devicetree change is required to make the port work in OTG mode (the battery charger IC has I2C comms)?
      • => This is essential to try to connect any USB device to the board.
      • => This seems a pretty basic thing to try, so this must have been done by someone I would think?

 

Thanks for any feedback on this!

 

Kind regards,

Arnout

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  • I had a quick look. In the devicetree there is reference of a bc3770 node for I2C0, but I can't find a corresponding driver.

    Moreover, an I2Cdetect yields nothing on the bus..

     

    Maybe I2c is not enabled by some gpio pins on the chip or something? I can clearly see in its datasheet that it is possible to configure the bc3770 in output mode on VBUS, but without I2C access, this is going to get tricky.

     

    Am I missing something?

  • in reply to arre

    I found it by looking at the schematics, datasheets and stuff.

     

    The I2C is disabled by default when no VBUS external power is applied, you need to pull up the SHDNB in order to be able to talk to it. (You can do this by using gpio140).

    Then, and only then, can you set register 7 to 1, which forces it to start boosting power to 5V, and hence you can use USB devices.

     

    Oh yea, and you have to change the device tree in order to make USB work in master mode instead of peripheral.

     

     

    Even though I got there, I am however used to -some- more support from a board, especially some basic stuff like this.

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  • in reply to arre

    I found it by looking at the schematics, datasheets and stuff.

     

    The I2C is disabled by default when no VBUS external power is applied, you need to pull up the SHDNB in order to be able to talk to it. (You can do this by using gpio140).

    Then, and only then, can you set register 7 to 1, which forces it to start boosting power to 5V, and hence you can use USB devices.

     

    Oh yea, and you have to change the device tree in order to make USB work in master mode instead of peripheral.

     

     

    Even though I got there, I am however used to -some- more support from a board, especially some basic stuff like this.

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