Hi, Neil Armstrong <narmstrong@xxxxxxxxxxxx> writes: > The USB support was initialy done with a set of PHYs and dwc3-of-simple > because the architecture of the USB complex was not understood correctly > at the time (and proper documentation was missing...). > > But with the G12A family, the USB complex was correctly understood and > implemented correctly. > But seems the G12A architecture was derived for the GXL USB architecture, > with minor differences and looks we can share most of the USB DWC3 glue > driver. > > This patchset refactors and adds callbacks to handle the architecture > difference while keeping the main code shared. > > The main difference is that on GXL/GXM the USB2 PHY control registers > are mixed with the PHY registers (we already handle correctly), and > the GLUE registers are allmost (99%) the same as G12A. > > But, the GXL/GXM HW is buggy, here are the quirks : > - for the DWC2 controller to reset correctly, the GLUE mux must be switched > to peripheral when the DWC2 controller probes. For now it's handled by simply > switching to device when probing the subnodes, but it may be not enough > - when manually switching from Host to Device when the USB port is not > populated (should not happen with proper Micro-USB/USB-C OTG switch), it > makes the DWC3 to crash. The only way to avoid that is to use the Host > Disconnect bit to disconnect the DWC3 controller from the port, but we can't > recover the Host functionnality unless resetting the DWC3 controller. > This bit is set when only manual switch is done, and a warning is printed > on manual switching. > > The patches 1-9 should be applied first, then either waiting the next release > or if the usb maintainer can provide us a stable tag, we can use it to merge > the DT and bindings. > > Changes since v1 at [1]: > - Fixed DT bindings to take in account usb2-phy2 on GXM > - Added comment in patch2 > - Fixed patch 5 and moved fix out > - Collected tags > - Lower DT patch changes, switch p20x-q20x port B as OTG by default patches 1-6 are applied to my testing/next -- balbi
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