Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Felipe Balbi <balbi@kernel.org>
To:     Neil Armstrong <narmstrong@baylibre.com>, kishon@ti.com,
        khilman@baylibre.com, martin.blumenstingl@googlemail.com
Cc:     Neil Armstrong <narmstrong@baylibre.com>,
        linux-amlogic@lists.infradead.org, linux-usb@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 00/14] usb: dwc3: meson: add OTG support for GXL/GXM
In-Reply-To: <20200326134507.4808-1-narmstrong@baylibre.com>
References: <20200326134507.4808-1-narmstrong@baylibre.com>
Date:   Sun, 29 Mar 2020 13:36:28 +0300
Message-ID: <87v9mne9cj.fsf@kernel.org>
MIME-Version: 1.0
Content-Type: multipart/signed; boundary="=-=-=";
        micalg=pgp-sha256; protocol="application/pgp-signature"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

--=-=-=
Content-Type: text/plain
Content-Transfer-Encoding: quoted-printable


Hi,

Neil Armstrong <narmstrong@baylibre.com> writes:
> The USB support was initialy done with a set of PHYs and dwc3-of-simple
> because the architecture of the USB complex was not understood correctly
> at the time (and proper documentation was missing...).
>
> But with the G12A family, the USB complex was correctly understood and
> implemented correctly.
> But seems the G12A architecture was derived for the GXL USB architecture,
> with minor differences and looks we can share most of the USB DWC3 glue
> driver.
>
> This patchset refactors and adds callbacks to handle the architecture
> difference while keeping the main code shared.
>
> The main difference is that on GXL/GXM the USB2 PHY control registers
> are mixed with the PHY registers (we already handle correctly), and
> the GLUE registers are allmost (99%) the same as G12A.
>
> But, the GXL/GXM HW is buggy, here are the quirks :
> - for the DWC2 controller to reset correctly, the GLUE mux must be switch=
ed
>   to peripheral when the DWC2 controller probes. For now it's handled by =
simply
>   switching to device when probing the subnodes, but it may be not enough
> - when manually switching from Host to Device when the USB port is not
>   populated (should not happen with proper Micro-USB/USB-C OTG switch), it
>   makes the DWC3 to crash. The only way to avoid that is to use the Host
>   Disconnect bit to disconnect the DWC3 controller from the port, but we =
can't
>   recover the Host functionnality unless resetting the DWC3 controller.
>   This bit is set when only manual switch is done, and a warning is print=
ed
>   on manual switching.
>
> The patches 1-9 should be applied first, then either waiting the next rel=
ease
> or if the usb maintainer can provide us a stable tag, we can use it to me=
rge
> the DT and bindings.
>
> Changes since v1 at [1]:
> - Fixed DT bindings to take in account usb2-phy2 on GXM
> - Added comment in patch2
> - Fixed patch 5 and moved fix out
> - Collected tags
> - Lower DT patch changes, switch p20x-q20x port B as OTG by default

patches 1-6 are applied to my testing/next

=2D-=20
balbi

--=-=-=
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----

iQIzBAEBCAAdFiEElLzh7wn96CXwjh2IzL64meEamQYFAl6Aei4ACgkQzL64meEa
mQaamxAAwuHxU4drRBYL0UhnH4ujHmfw9zVuZeEVjxAf0eTeCXjxw0u76bgZlbm1
z407kK9bU2znxIUFAEtYZ8SNuPQcnGkEkJBRIAKr9sBlcoqnVl0I6UCCgpAhZh0P
/Mkpea+QjUrtIgojPkyM9xnxi42+JwBT6S+rGqgq9KulVVC5TzNWTY5b3IvlJinW
7OruoTHahtfiVqSi5DOzzNRsWvX6R6JolMq8wsa1KOQiVnlB0GTLJFqf8TKrZgWn
/PQpbbhk5MUnDgUTIaOWYbfcJrUZd4yt0kkgH8tO3jIH8getvK3JKgZcrsQQ2em6
gmXrQ+o64TaJ+5RFNMJknhcMfnB5jKCAWj8FVHB2P/wOFt1eHu6XOIxBozraEkYW
OEa+3RNEFilashPRbm7plsHlqQX98HpliM2+p7mtcgTjWKJeDRMiBc2RXqd8SKcp
U7kwWYGv6BZ/EVncImIHgVJ2uTvriB+yeUuMVrZU8u/Rr3eRaOHikb/KJANh00k/
UlpxS89UD2zAd+HT3BqVYuzvtoKJOYO8z0d6DlvV/bzaxSOpWoIFNEL8tGjGDRtu
R9HlOcqhoi3amtqVFMR+huIB6ZQIcilLcNA+1mzxwq0qXyVNA+oyY2dskRhgoV+t
kFZs/a6g4e5bN8HxaWdDeEdWgts/Cmz+A4PfCTsD26XKggaw8f4=
=uyGs
-----END PGP SIGNATURE-----
--=-=-=--