Hi Martin, On Tue, 21 Sept 2021 at 00:56, Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> wrote: > > Hi Anand, > > On Tue, Aug 31, 2021 at 10:48 PM Anand Moon <linux.amoon@xxxxxxxxx> wrote: > [...] > > After enabling CONFIG_REGULATOR_DEBUG, with this patch applied > > I still not getting the USB regulator to enable. > > Do you see different output at your end? > I don't have much time for testing and debugging currently but I'll > put it on my TODO-list > Until either of us has found the issue I suggest not merging this patch. > Ok no problem. Basically, I have just roughly gone through the architecture of Amlogic's OTG framework. Below is the global configuration registers for DWC2 OTG framer work [0] https://github.com/hardkernel/linux/blob/odroidc-3.10.y/drivers/amlogic/usb/dwc_otg/310/dwc_otg_regs.h#L66-L151 Within some configurations, it helps tune the power for vbus and interrupt For example [1] https://github.com/hardkernel/linux/blob/odroidc-3.10.y/drivers/amlogic/usb/dwc_otg/310/dwc_otg_attr.c#L666-L717 Amlogic basically used the mode parameter to external tune the DWC2 driver it could help more fine-tuning the driver. [2] https://github.com/hardkernel/linux/blob/odroidc-3.10.y/drivers/amlogic/usb/dwc_otg/310/dwc_otg_driver.c#L1461-L1703 I feel we need to identify many more PHY tuning parameters to make the USB work correctly. Thanks -Anand > > Best regards, > Martin
