[v13,0/7] usb: misc: Add onboard_usb_hub driver

This series adds:
- the onboard_usb_hub_driver
- glue in the xhci-plat driver to create and destroy the
  onboard_usb_hub platform devices if needed
- a device tree binding for the Realtek RTS5411 USB hub controller
- device tree changes that add RTS5411 entries for the QCA SC7180
  based boards trogdor and lazor
- a couple of stubs for platform device functions to avoid
  unresolved symbols with certain kernel configs

The main issue the driver addresses is that a USB hub needs to be
powered before it can be discovered. For discrete onboard hubs (an
example for such a hub is the Realtek RTS5411) this is often solved
by supplying the hub with an 'always-on' regulator, which is kind
of a hack. Some onboard hubs may require further initialization
steps, like changing the state of a GPIO or enabling a clock, which
requires even more hacks. This driver creates a platform device
representing the hub which performs the necessary initialization.
Currently it only supports switching on a single regulator, support
for multiple regulators or other actions can be added as needed.
Different initialization sequences can be supported based on the
compatible string.

Besides performing the initialization the driver can be configured
to power the hub off during system suspend. This can help to extend
battery life on battery powered devices which have no requirements
to keep the hub powered during suspend. The driver can also be
configured to leave the hub powered when a wakeup capable USB device
is connected when suspending, and power it off otherwise.

Changes in v13:
- added patch "usb: Specify dependency on USB_XHCI_PLATFORM with
  'depends on'" to the series to avoid Kconfig conflicts
- added patch "arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM"
  to the series to keep effective defconfig unchanged

Changes in v12:
- onboard_hub driver: use IS_ENABLED(CONFIG_USB_ONBOARD_HUB_MODULE)
  in onboard_hub.h to also check for the driver built as module
- onboard_hub_driver: include onboard_hub.h again to make sure there
  are prototype declarations for the public functions

Changes in v11:
- support multiple onboard hubs connected to the same parent
- don't include ‘onboard_hub.h’ from the onboard hub driver

Changes in v10:
- always use of_is_onboard_usb_hub() stub unless ONBOARD_USB_HUB=y/m
- keep 'regulator-boot-on' property for pp3300_hub

Changes in v9:
- added dependency on ONBOARD_USB_HUB (or !!ONBOARD_USB_HUB) to
  USB_PLATFORM_XHCI

Changes in v7:
- updated DT binding
- series rebased on qcom/arm64-for-5.13

Changes in v6:
- updated summary

Changes in v5:
- cover letter added

Matthias Kaehlcke (7):
  dt-bindings: usb: Add binding for Realtek RTS5411 hub controller
  usb: misc: Add onboard_usb_hub driver
  of/platform: Add stubs for of_platform_device_create/destroy()
  arm64: defconfig: Explicitly enable USB_XHCI_PLATFORM
  usb: Specify dependencies on USB_XHCI_PLATFORM with 'depends on'
  usb: host: xhci-plat: Create platform device for onboard hubs in
    probe()
  arm64: dts: qcom: sc7180-trogdor: Add nodes for onboard USB hub

 .../sysfs-bus-platform-onboard-usb-hub        |   8 +
 .../bindings/usb/realtek,rts5411.yaml         |  62 +++
 MAINTAINERS                                   |   7 +
 .../boot/dts/qcom/sc7180-trogdor-lazor-r0.dts |  19 +-
 .../boot/dts/qcom/sc7180-trogdor-lazor-r1.dts |  12 +-
 .../arm64/boot/dts/qcom/sc7180-trogdor-r1.dts |  19 +-
 arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi  |  19 +-
 arch/arm64/configs/defconfig                  |   1 +
 drivers/usb/cdns3/Kconfig                     |   2 +-
 drivers/usb/dwc3/Kconfig                      |   3 +-
 drivers/usb/host/Kconfig                      |   5 +-
 drivers/usb/host/xhci-plat.c                  |   6 +
 drivers/usb/host/xhci.h                       |   2 +
 drivers/usb/misc/Kconfig                      |  17 +
 drivers/usb/misc/Makefile                     |   1 +
 drivers/usb/misc/onboard_usb_hub.c            | 497 ++++++++++++++++++
 include/linux/of_platform.h                   |  22 +-
 include/linux/usb/onboard_hub.h               |  18 +
 18 files changed, 682 insertions(+), 38 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-platform-onboard-usb-hub
 create mode 100644 Documentation/devicetree/bindings/usb/realtek,rts5411.yaml
 create mode 100644 drivers/usb/misc/onboard_usb_hub.c
 create mode 100644 include/linux/usb/onboard_hub.h

Will/Catalin,

does this change looks good to you and could get an Acked-by?

If so: would it be ok to land it through the USB tree with the
rest of the series? It seems a conflict would be relatively
unlikely.

Thanks

Matthias

On Wed, Jun 23, 2021 at 11:41:20AM -0700, Matthias Kaehlcke wrote:
> The dependency of USB_DWC3 on USB_XHCI_PLATFORM is being changed
> from 'select' to 'depends on' by another patch. The defconfig selects
> USB_DWC3 and implicitly USB_DWC3_DUAL_ROLE, to keep this unchanged
> USB_XHCI_PLATFORM now needs to be selected explicitly.
> 
> Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
> ---
> 
> Changes in v13:
> - patch added to the series
> 
>  arch/arm64/configs/defconfig | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
> index 08c6f769df9a..d7f22b18e37a 100644
> --- a/arch/arm64/configs/defconfig
> +++ b/arch/arm64/configs/defconfig
> @@ -795,6 +795,7 @@ CONFIG_USB_CONN_GPIO=m
>  CONFIG_USB=y
>  CONFIG_USB_OTG=y
>  CONFIG_USB_XHCI_HCD=y
> +CONFIG_USB_XHCI_PLATFORM=y
>  CONFIG_USB_XHCI_TEGRA=y
>  CONFIG_USB_EHCI_HCD=y
>  CONFIG_USB_EHCI_EXYNOS=y
> -- 
> 2.32.0.288.g62a8d224e6-goog
>

Hi,

On Mon, Jul 19, 2021 at 8:58 AM Matthias Kaehlcke <mka@chromium.org> wrote:
>
> Will/Catalin,
>
> does this change looks good to you and could get an Acked-by?
>
> If so: would it be ok to land it through the USB tree with the
> rest of the series? It seems a conflict would be relatively
> unlikely.

Officially I don't think you really need an Ack for most changes to
this file. So says Will [1]:

> although there are a few things I really care about
> in defconfig (e.g. things like page size!), generally speaking we don't
> need to Ack everything that changes in there.

In case it helps, you can stick my Reviewed-by on there...

Reviewed-by: Douglas Anderson <dianders@chromium.org>

[1] https://lore.kernel.org/r/20201208160029.GA6461@willie-the-truck

On Mon, Jul 19, 2021 at 11:07:23AM -0700, Doug Anderson wrote:
> Hi,
> 
> On Mon, Jul 19, 2021 at 8:58 AM Matthias Kaehlcke <mka@chromium.org> wrote:
> >
> > Will/Catalin,
> >
> > does this change looks good to you and could get an Acked-by?
> >
> > If so: would it be ok to land it through the USB tree with the
> > rest of the series? It seems a conflict would be relatively
> > unlikely.
> 
> Officially I don't think you really need an Ack for most changes to
> this file. So says Will [1]:
> 
> > although there are a few things I really care about
> > in defconfig (e.g. things like page size!), generally speaking we don't
> > need to Ack everything that changes in there.

Good to know, thanks!

> In case it helps, you can stick my Reviewed-by on there...
> 
> Reviewed-by: Douglas Anderson <dianders@chromium.org>

Thanks

I figured the next step is actually a rebase due to a conflict in
v5.14-rc1, commit 8ae030c34dce ("arm64: defconfig: Enable renesas
usb xhci pci host controller") made changes in the same area of
the config.