[PATCH v3 0/8] usb: dwc3: meson: add OTG support for GXL/GXM

[Neil Armstrong]

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 PHYs are powered up.
- 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 1-3 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 v2 at [2]:
- Removed first 6 applied patches
- rebased on usb/testing/next
- Fixed dwc3_meson_g12a_usb2_init in patch 1
- Fixed leftover usage of dwc3_meson_g12a_usb_init in patch 1
- Moved post_init callback before child node probe to avoid bad dwc3 init

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

[1] http://lkml.kernel.org/r/20200324102030.31000-1-narmstrong@xxxxxxxxxxxx
[2] http://lkml.kernel.org/r/20200326134507.4808-1-narmstrong@xxxxxxxxxxxx

Martin Blumenstingl (4):
  arm64: dts: amlogic: use the new USB control driver for GXL and GXM
  phy: amlogic: meson-gxl-usb3: remove code for non-existing PHY
  usb: dwc3: of-simple: remove Amlogic GXL and AXG compatibles
  dt-bindings: usb: dwc3: remove old DWC3 wrapper

Neil Armstrong (4):
  usb: dwc3: meson-g12a: refactor usb init
  usb: dwc3: meson-g12a: support the GXL/GXM DWC3 host phy disconnect
  usb: dwc3: meson-g12a: add support for GXL and GXM SoCs
  doc: dt: bindings: usb: dwc3: remove amlogic compatible entries

 .../bindings/phy/meson-gxl-usb3-phy.txt       |  31 --
 .../devicetree/bindings/usb/amlogic,dwc3.txt  |  42 ---
 .../devicetree/bindings/usb/dwc3.txt          |   2 -
 .../dts/amlogic/meson-gx-libretech-pc.dtsi    |   3 +-
 .../boot/dts/amlogic/meson-gx-p23x-q20x.dtsi  |   3 +-
 .../amlogic/meson-gxl-s805x-libretech-ac.dts  |   3 +-
 .../boot/dts/amlogic/meson-gxl-s805x-p241.dts |   3 +-
 .../amlogic/meson-gxl-s905d-phicomm-n1.dts    |   4 +
 .../boot/dts/amlogic/meson-gxl-s905w-p281.dts |   4 +
 .../dts/amlogic/meson-gxl-s905w-tx3-mini.dts  |   4 +
 .../amlogic/meson-gxl-s905x-khadas-vim.dts    |   4 +
 .../amlogic/meson-gxl-s905x-libretech-cc.dts  |   3 +-
 .../amlogic/meson-gxl-s905x-nexbox-a95x.dts   |   3 +-
 .../dts/amlogic/meson-gxl-s905x-p212.dtsi     |   3 +-
 arch/arm64/boot/dts/amlogic/meson-gxl.dtsi    |  45 +--
 .../dts/amlogic/meson-gxm-khadas-vim2.dts     |   3 +-
 .../boot/dts/amlogic/meson-gxm-nexbox-a1.dts  |   3 +-
 .../boot/dts/amlogic/meson-gxm-vega-s96.dts   |   4 +
 arch/arm64/boot/dts/amlogic/meson-gxm.dtsi    |   7 +-
 drivers/phy/amlogic/Kconfig                   |  12 -
 drivers/phy/amlogic/Makefile                  |   1 -
 drivers/phy/amlogic/phy-meson-gxl-usb3.c      | 283 ------------------
 drivers/usb/dwc3/dwc3-meson-g12a.c            | 188 +++++++++++-
 drivers/usb/dwc3/dwc3-of-simple.c             |  30 +-
 24 files changed, 246 insertions(+), 442 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/phy/meson-gxl-usb3-phy.txt
 delete mode 100644 Documentation/devicetree/bindings/usb/amlogic,dwc3.txt
 delete mode 100644 drivers/phy/amlogic/phy-meson-gxl-usb3.c

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2.22.0