[PATCH v4 0/3] initialize (multiple) PHYs in xhci-plat

[Martin Blumenstingl]

Hello Greg, Hello Mathias,

On Mon, Sep 18, 2017 at 10:49 AM, Greg KH <gregkh at linuxfoundation.org> wrote:
> On Sun, Sep 17, 2017 at 10:51:31PM +0200, Martin Blumenstingl wrote:
>> Hello Mathias, Hello Greg,
>>
>> On Sun, Sep 3, 2017 at 11:38 PM, Martin Blumenstingl
>> <martin.blumenstingl at googlemail.com> wrote:
>> > This series is the outcome of a discussion with Felipe Balbi,
>> > see [0] and [1].
>> > The quick-summary of this is:
>> > - dwc3 already takes one USB2 and one USB3 PHY and initializes these
>> >   correct
>> > - some other HCI platform drivers (like ehci-platform.c, xhci-mtk.c and
>> >   ohci-platform.c) do not have a limitation on the number of PHYs - they
>> >   support one PHY per actual host port
>> > - Amlogic Meson GXL and GXM SoCs come with a dwc3 IP block which has two
>> >   or three USB2 ports enabled on the internal root-hub. The SoCs also
>> >   provide separate USB2 PHYs, one per port. All USB2 PHYs (which are
>> >   internally "connected" to the dwc3 roothub) need to be powered on,
>> >   otherwise USB devices cannot be enumerated (even if just one PHY is
>> >   disabled and if the device is plugged into another, enabled port)
>> >
>> > In my first attempt to get USB supported on the GXL and GXM SoCs I tried
>> > to work-around the problem that I could not pass multiple PHYs to the
>> > dwc3 controller.
>> > This was rejected by Rob Herring (which was definitely the thing to do in
>> > my opinion), see [2]
>> >
>> > This series adds a new "platform-roothub". This can be configured through
>> > devicetree by passing a child-node with "reg = <0>" to the USB
>> > controller. Additionally there has to be a child-node for each port on
>> > the root-hub. Each of the child-nodes takes a "phys" and "phy-names"
>> > property. This allows modeling the root-hub in devicetree similar to the
>> > USB device binding (documented in devicetree/bindings/usb/usb-device.txt)
>> > This avoids and backwards-compatibility problems (which was a concern
>> > regardless of the solution, see [3]) since the binding for the root-hub
>> > was previously not specified (and we're not using the "phys" property of
>> > the controller, which might have served different purposes before,
>> > depending on the drivers).
>> >
>> > Additionally this integrates the new platform-roothub into xhci-plat.c
>> > which automatically enables it for the dwc3 driver (in host-mode).
>> >
>> >
>> > Changes since RFCv3 at [6]:
>> > - moved the DT binding change from patch #3 to patch #1 as suggested
>> >   by Rob Herring (and slightly adjusted the commit message to account
>> >   for that)
>> > - added Tested-by from Chunfeng Yun (who confirmed that the whole
>> >   concept and implementation works fine on Mediatek SoCs - many thanks
>> >   again!) to patch #2
>> > - added Rob Herring's ACK to patches 1 and 3
>> > - dropped RFC status (RFCv3 -> PATCH v4)
>> I just wanted to rebase this to v4.14-rc1 (now that this is out) -
>> however I noticed that v4 still applies to v4.14-rc1 cleanly (the
>> patches are still identical to v4 after rebasing).
>>
>> we have an ACK from the devicetree maintainers and a "Tested-by" for a
>> Mediatek (= non-Amlogic) SoC.
>> I already have patches for the Amlogic GXL/GXM platforms queued, those
>> are just waiting on this series.
>>
>> what is still missing to get this series into v4.15?
>
> Well, we couldn't do anything until 4.14-rc1 is out, now that it is, let
> us catch up on patch review please...
OK, I understand that.
please let me know once you've caught up with the review backlog - as
I said I would like to get this into 4.15 if nothing else comes up
during the code-review


Thank you!
Regards,
Martin