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

Jerome Brunet jbrunet at baylibre.com
Mon Oct 2 05:35:08 PDT 2017


On Sun, 2017-10-01 at 22:32 +0200, Martin Blumenstingl wrote:
> 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

This series works well on the libretech-cc (le potato)
For the series:

Tested-by: Jerome Brunet <jbrunet at baylibre.com>


> 
> 
> Thank you!
> Regards,
> Martin
> 
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