On 29/03/2020 12:36, Felipe Balbi wrote: > > 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 > Thanks ! Neil
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