On Tue, Sep 13, 2016 at 08:05:32PM +0200, Fabien Lahoudere wrote: > Hi Peter, > > >> > >>This is our device tree imx-ppd.dts: > > > >I may know the reason why you meet hang at current flow, you are using > >generic phy driver, and the PHY clock is enabled at phy_init which is > >called later than setting portsc.pts. The current flow to enable ULPI > >phy is like below: > > This explains why the patch works if USBPHY_INTERFACE_MODE_ULPI works as > USBPHY_INTERFACE_MODE_UTMI. because _ci_usb_phy_init(ci) initialise clock > and generator. Yes. > > > > >1. Enable ULPI and choose its clock select at usbmisc, which you have > >already done. > >2. Enable the input clock for ULPI > > This is done by _ci_usb_phy_init(ci); and this function only do this so I > think we should have in ci_usb_phy_init(ci);: > case USBPHY_INTERFACE_MODE_ULPI: > ret = _ci_usb_phy_init(ci); > if (!ret) > hw_wait_phy_stable(); > else > return ret; > >3. set portsc.pts > > > hw_phymode_configure(ci); > ci_ulpi_phy_init(ci); // to init ULPI specific config once portsc.pts is > enabled > break; > > >You may need to have a ULPI PHY driver which do some power sequence > >(clock, regulator, etc) before setting portsc.pts and visit ULPI > >register. > This is already done by _ci_usb_phy_init(ci); > > In conclusion, I think USBPHY_INTERFACE_MODE_ULPI should work as > USBPHY_INTERFACE_MODE_UTMI but with an extra function to visit ULPI register > (ci_ulpi_phy_init(ci);). > Am I wrong? Currently, you are using generic PHY driver which does not intends for ULPI PHY uses, looks at usb/phy/phy-upi.c and usb/common/ulpi.c, both need to read id at its initialization. > > > > >I am also a little confused how Stephen Boyd's ULPI driver for qualcomm > >platform, I will cc on discussion. > > As you ask me earlier maybe he init clock from bootloader. Yes, his PHY input clock is always on. Stephen boyd's ulpi support at chipidea is the correct way. For your case, you can create a generic ULPI PHY driver, and registered it on ulpi bus, but you still need power sequence for your case. I am afraid you may use your hack temporarily at local, once Stephen's patch and power sequence patch set are queued, you can submit your changes. -- Best Regards, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
