[PATCH v4 0/3] arm64: meson: support Amlogic A1 USB OTG controller

[Dmitry Rokosov]

This patch series introduces full support for the Amlogic A1 USB controller
in OTG mode (peripheral and host modes switching).

Previously, Amlogic's patch series [1] was applied to the upstream tree,
but it only had USB host mode support.
Furthermore, the device tree patchset [2] wasn't merged due to a missing
clk driver.
Patchset [2] has been completely reworked:
    - changed register base offsets to proper values
    - introduced dwc2 in peripheral mode
    - OTG mode support
    - the SoB of Amlogic authors still remain

Testing:
    - USB OTG role switching between gadget and host - OK
    - Peripheral mode - OK (tested with adb shell/push/pop)
    - Host mode - OK (tested only USB enumeration and detection)

Changes v4 since v3 at [5]:
    - remove the dtsi patchset from series because it is dependent on the
      A1 clock bindings, which are not resolved yet; this is due to the
      fact that the A1 clock drivers are currently under review
    - remove the patchset for phy as it has already been applied by Vinod
      to phy/next at [6]

Changes v3 since v2 at [4]:
    - if reset_control_reset() fails during phy_exit() callback
      execution, do not disable clkin, instead, return an error
      immediately
    - provide proper 'phy-names' for the dwc2 device tree node as
      'usb2-phy' instead of 'usb2_phy' (replace underscore with dash)

Changes v2 since v1 at [3]:
    - as Martin suggested in v1, this commit completely removes
      the 'otg_switch_supported' parameter from dwc3_meson_g12a_drvdata;
      this parameter is no longer necessary as all IP versions now
      support OTG switching
    - this commit moves the USB PHY clkin enable/disable calls to
      the PHY init/exit routines

Links:
    [1] https://lore.kernel.org/all/1581990859-135234-1-git-send-email-hanjie.lin@amlogic.com/
    [2] https://lore.kernel.org/all/1581990859-135234-4-git-send-email-hanjie.lin@amlogic.com/
    [3] https://lore.kernel.org/all/20230414152423.19842-1-ddrokosov@sberdevices.ru/
    [4] https://lore.kernel.org/all/20230418111612.19479-1-ddrokosov@sberdevices.ru/
    [5] https://lore.kernel.org/all/20230426102922.19705-1-ddrokosov@sberdevices.ru/
    [6] https://lore.kernel.org/all/ZFjAmCcc%2F35MhcuI@matsya/

Dmitry Rokosov (3):
  usb: dwc2: support dwc2 IP for Amlogic A1 SoC family
  dt-bindings: usb: dwc2: add support for Amlogic A1 SoC USB peripheral
  usb: dwc3-meson-g12a: support OTG switch for all IP versions

 .../devicetree/bindings/usb/dwc2.yaml         |  1 +
 drivers/usb/dwc2/params.c                     | 21 +++++++++++++++++++
 drivers/usb/dwc3/dwc3-meson-g12a.c            | 16 +++-----------
 3 files changed, 25 insertions(+), 13 deletions(-)

-- 
2.36.0