From: Andre Przywara <andre.przywara@arm.com>
To: Chen-Yu Tsai <wens@csie.org>
Cc: Mark Rutland <mark.rutland@arm.com>,
devicetree <devicetree@vger.kernel.org>,
Rob Herring <robh@kernel.org>,
Maxime Ripard <maxime.ripard@bootlin.com>,
linux-sunxi <linux-sunxi@googlegroups.com>,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] arm64: dts: allwinner: properly connect USB PHY to port 0
Date: Mon, 24 Jun 2019 13:58:06 +0100 [thread overview]
Message-ID: <20190624135806.7bc78378@donnerap.cambridge.arm.com> (raw)
In-Reply-To: <CAGb2v66WOTFvXWSSGwtLh3hD+N4CeJkFEPnCMXp0FuU2h=LS9Q@mail.gmail.com>
On Mon, 24 Jun 2019 16:25:47 +0800
Chen-Yu Tsai <wens@csie.org> wrote:
Hi,
> On Thu, Jun 20, 2019 at 9:02 AM Andre Przywara <andre.przywara@arm.com> wrote:
> >
> > In recent Allwinner SoCs the first USB host controller (HCI0) shares
> > the first PHY with the MUSB controller. Probably to make this sharing
> > work, we were avoiding to declare this in the DT. This has two
> > shortcomings:
> > - U-Boot (which uses the same .dts) cannot use this port without a PHY
> > linked, so we were loosing one USB port there.
> > - It requires the MUSB driver to be enabled and loaded, although we
> > don't actually use it.
> >
> > For those (64-bit) boards which use an USB-A socket for HCI0/MUSB, add
> > a "phys" property pointing to the USB PHY 0.
> >
> > This makes it work in U-Boot, also improves compatiblity when no MUSB
> > driver is loaded (for instance in distribution installers).
> >
> > Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> > ---
> > Hi,
> >
> > I have the feeling this belongs into the .dtsi, but cant't tell for sure
> > how this interacts with the MUSB driver. If need be, we can always pull
> > this up later, I guess.
>
> Have you tried if gadget mode and switching between gadget/host mode on
> an otg port still works? AFAICT that would be the main thing to worry
> about.
I briefly tried gadget mode on a BPi-M64, and that still seemed to work,
but I couldn't switch it to host mode. IIRC that didn't even work without
this patch, but I didn't find the time to investigate yet.
Is it supposed to switch automatically when the ID pin changes state? Do
you know a board/kernel combination which is known to work?
Cheers,
Andre.
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next prev parent reply other threads:[~2019-06-24 12:58 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-20 1:01 [PATCH] arm64: dts: allwinner: properly connect USB PHY to port 0 Andre Przywara
2019-06-24 8:25 ` Chen-Yu Tsai
2019-06-24 12:58 ` Andre Przywara [this message]
2019-06-24 13:03 ` Chen-Yu Tsai
2019-06-27 3:34 ` Chen-Yu Tsai
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