[PATCH 0/4] USB host support for TQMa8MPxL + MBa8MPxL

[Alexander Stein]

Hi everybody,

this is a series based on the RFC at [1] for USB host support on TQMa8MPxL +
MBa8MPxL. The main difference is that USB DR support has already been added and
has been removed from this series.

The DT configuration itself (patch 4) is rather straight forward, but leads to
the following dmesg errors regarding superspeed ports:
> [    8.549243] hub 2-1:1.0: hub_ext_port_status failed (err = -110)
> [   22.885263] usb 2-1: Failed to suspend device, error -110

This hardware works fine using the downstream kernel, because for imx8mp this
ITP sync feature is enabled conditionally [2] & [3].
Hacking this into mainline resulted in a working superspeed setup as well. I
also noticed that on some android kernel [4] depending in IP core version either
GCTL.SOFTITPSYNC or GFLADJ.GFLADJ_REFCLK_LPM_SEL is enabled unconditionally.
So I opted for the latter one using some quirk (patch 1-3).

I have to admit I do not know what this is actually about, nor why my setup
does not work without this change or why this fixed my problem. So maybe
someone with more knowledge can say if this is the way to go or what this is
about.

I also added snps,dis_u3_susphy_quirk to the board level as for some reason
USB Superspeed U3 does not work. Detecting the onboard hub takes much longer
and once all devices are diconnected from the hub it is put into runtime
suspend (U3) and new attached devices are not detected at all. Until the cause
is known and fixed runtime suspend has to be disabled.

Thanks and best regards,
Alexander

[1] https://lore.kernel.org/all/20220622130440.955465-1-alexander.stein@xxxxxxxxxxxxxxx/
[2] https://source.codeaurora.org/external/imx/linux-imx/tree/drivers/usb/dwc3/dwc3-imx8mp.c?h=lf-5.10.y#n134
[3] https://source.codeaurora.org/external/imx/linux-imx/tree/drivers/usb/dwc3/core.c?h=lf-5.10.y#n333
[4] https://android.googlesource.com/kernel/msm/+/87a6b154766907020cc74c7726e8a68aaa9d7f6b%5E%21/#F0

Alexander Stein (4):
  dt-bindings: usb: dwc3: Add gfladj-refclk-lpm-sel-quirk
  usb: dwc3: core: add gfladj_refclk_lpm_sel quirk
  arm64: dts: imx8mp: Add snps,gfladj-refclk-lpm-sel quirk to USB nodes
  arm64: dts: tqma8mpql: add support for 2nd USB (host) interface

 .../devicetree/bindings/usb/snps,dwc3.yaml    |  5 +++
 .../freescale/imx8mp-tqma8mpql-mba8mpxl.dts   | 42 +++++++++++++++++++
 arch/arm64/boot/dts/freescale/imx8mp.dtsi     |  2 +
 drivers/usb/dwc3/core.c                       |  8 +++-
 drivers/usb/dwc3/core.h                       |  2 +
 5 files changed, 58 insertions(+), 1 deletion(-)

-- 
2.25.1