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twl4030-usb.ko

Chris Read
Genius 3345 points
Other Parts Discussed in Thread: TPS65950, OMAP3530

I am using a design that has the TPS65950 USB PHY attached to an OMAP3530 OTG (MUSB) port, and am struggling to get the OMAP to go into idle mode.  I have a thread in the OMAP group on the OMAP side of things, but wanted to ask about the PHY driver.

1.  The twl4030-usb driver can be made as a module, and seems to insmod and rmmod just fine.  Are there any known issues with insmod-ing and rmmod-ing the driver?

a.  Any reason that doing so would keep the OMAP side active when it doesn't need to be?

b.  I note that the VUSB1.5, VUSB1.8, and VUSB3.1 power off when the driver is rmmod-ed, and turn on when it's insmod-ed, but I don't see them turn off at other times.

i. Should they turn off if nothing is connected to the USB port?

ii. Will the driver still work if they are turned off and back on by some mechanism other than the driver?  (i.e. some other kernel mechanism sets the DEV_GRP to 0 and back to DEV_GRP_ALL)

2. Are there any patches I should be aware of?

3. Can the NOP PHY (NOP_USB_XCEIV) be removed from the kernel build when using the TPS65950 PHY instead of the external PHY on the EVM?

4. Is there any configuration information that should be in the board file to logically/physically connect the TPS65950's PHY to the OMAP's OTG port?

  • 0
    TI__Genius 15100 points

    Hi Chris,

    I think you can get correct help from the OMAP software thread that you have.

    Pardon my ignorance, the software terminology you used is new to me. Software isnt my expertise.

    As for the USB LDOs, you can turn these off if not required, except USB 3.1V LDO. You can configure this in sleep mode, other internal analog circuitry would need this to be at 3.1V (low power mode is ok).

    If the USB port is not used then there is no need to have the LDOs ON (except 3.1V as mentioned above)

    I dont know the requirements for OMAP to go to idle mode. I dont know how PHY being ON will stop OMAP idle mode, maybe some communication between PHY and LINK is active, not sure though. You can try turning the LDOs OFF and see if it helps.

    I hope this information helps.

     

    Regards,

    Gandhar.

     

  • 0 in reply to Gandhar Dighe
    Genius 3345 points

    Gandhar Dighe said:

    As for the USB LDOs, you can turn these off if not required, except USB 3.1V LDO. You can configure this in sleep mode, other internal analog circuitry would need this to be at 3.1V (low power mode is ok).

    If the USB port is not used then there is no need to have the LDOs ON (except 3.1V as mentioned above)

     

    In the TRM it states that USB 3.1V is used for MCPC and CarKit.  I am not using CarKit or MCPC, though I am using ADCIN5.  Can USB 3.1V be turned off whenever I don't want to us USB?

     

    Thanks,

     

    Chris