Re: [PATCH 00/13] usb: dwc3: meson: add OTG support for GXL/GXM
From: Neil Armstrong
Date: Thu May 14 2020 - 08:42:22 EST
Hi,
On 14/05/2020 12:23, Felipe Balbi wrote:
> Felipe Balbi <balbi@xxxxxxxxxx> writes:
>
>> 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 controlle 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 1-8 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.
>>
>> it's unclear to me if this series is ready to be merged. Can someone
>> confirm? If it is, can you resend with all reviewed by tags in place?
>
> Are we getting a v2 for this?
>
Yes, even a v3 with reviews on all patches:
http://lkml.kernel.org/r/20200416121910.12723-1-narmstrong@xxxxxxxxxxxx
Neil
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