From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felipe Balbi Subject: Re: [PATCH v2 2/2] arm: dts: add support for AM437x StarterKit Date: Wed, 18 Jun 2014 23:02:30 -0500 Message-ID: <20140619040230.GA15073@saruman.home> References: <1403106200-777-1-git-send-email-balbi@ti.com> <1403106200-777-3-git-send-email-balbi@ti.com> <53A1BADD.7050309@ti.com> <20140618193113.GC4570@saruman.home> <53A20A7D.3060508@ti.com> <20140618231923.GA9855@saruman.home> <53A24A39.4080100@ti.com> <20140619030520.GA13805@saruman.home> <53A2564E.2080600@ti.com> Reply-To: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="huq684BweRXVnRxX" Return-path: Content-Disposition: inline In-Reply-To: <53A2564E.2080600@ti.com> Sender: linux-kernel-owner@vger.kernel.org To: Nishanth Menon Cc: balbi@ti.com, devicetree@vger.kernel.org, linux@arm.linux.org.uk, Benoit Cousson , Tony Lindgren , Rajendra Nayak , Linux Kernel Mailing List , Darren Etheridge , r.sricharan@ti.com, robh+dt@kernel.org, Josh Elliot , galak@codeaurora.org, Linux OMAP Mailing List , Linux ARM Kernel Mailing List List-Id: devicetree@vger.kernel.org --huq684BweRXVnRxX Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Wed, Jun 18, 2014 at 10:17:34PM -0500, Nishanth Menon wrote: > On 06/18/2014 10:05 PM, Felipe Balbi wrote: > > Hi, > >=20 > > On Wed, Jun 18, 2014 at 09:26:01PM -0500, Nishanth Menon wrote: > >> On 06/18/2014 06:19 PM, Felipe Balbi wrote: > >> [...] > >>>>>>> Add support for TI's AM437x StarterKit Evaluation > >>>>>>> Module. > >>>>>> > >>>>>> is there a link for this platform? > >>>>> > >>>>> internal only > >>>> > >>>> but will eventually be sold externally? I assume this is not an TI > >>> > >>> probably, but there's nothing public yet. > >>> > >>>> internal only board. > >>> > >>> correct assumption for all I know. > >> > >> Yikes.. ok.. I'd let Tony et.al make the call on this, I guess. > >=20 > > would we really block a DTS just because there's no public wiki page > > available (yet) ? > >=20 > > Sounds a bit extreme to me. >=20 > If this is an TI internal board without anyone outside that a few > select developers being able to get and work on it... I am a bit > skeptical on upstream kernel support and burden for forseeable future > in ensuring it is tested and continually maintained. if it an > one-off.. maybe fork might be good enough.. upstream not too attractive. dude, this is a Starter Kit after all. The probability of being sold eventually is really, really high. I just can't confirm it certainly will right now. > I mean, if it is targeted to be sold eventually, I have no objections > or blocks - just make it clear in commit message. I can imagine folks > wondering what the heck this is and googling without results(just like > I did). I'll point you to schematics and internal wiki tomorrow if you want. I'm sure there will be a public ti.com address for it though. > [...] >=20 > >>>>>>> + cd-gpios =3D <&gpio0 6 GPIO_ACTIVE_HIGH>; > >>>>>>> +}; > >>>>>>> + > >>>>>>> +&usb2_phy1 { > >>>>>>> + status =3D "okay"; > >>>>>>> +}; > >>>>>>> + > >>>>>>> +&usb1 { > >>>>>>> + dr_mode =3D "peripheral"; > >>>>>>> + status =3D "okay"; > >>>>>>> +}; > >>>>>>> + > >>>>>>> +&usb2_phy2 { > >>>>>>> + status =3D "okay"; > >>>>>>> +}; > >>>>>>> + > >>>>>>> +&usb2 { > >>>>>>> + dr_mode =3D "host"; > >>>>>>> + status =3D "okay"; > >>>>>>> +}; > >>>>>> none of the above need pinctrl? no regulator supplies? > >>>>> > >>>>> pins in default states, drivers don't use regulators. > >>>> > >>>> USB works without a supply? even a fixed voltage supply? that is > >>>> weird. > >>> > >>> take a look at the minicom output I posted if you don't believe. Well, > >>> to be exact, tps63010 [1] is the one which generates the regulated V5= _0D > >>> which is used as VBUS_USB. The enable pin in that device is tied to t= he > >>> 3v3 rail (dcdc4 regulator in the PMIC as most everything else) but > >>> there's no way (otherwise) to control that thing. There's no control > >>> bus, no way to write a driver. > >>> > >>> Since the board will anyways turn off if you disable the 3v3 rail, it= 's > >>> pretty much pointless to figure out a hack just to add this to DTS. > >>> > >>> [1] http://www.ti.com/product/TPS63010 > >> > >> I am sure to trust you on the test log :) -> but then from dts descri= ption > >> perspective, it is good if we describe the supplies, even as a always = on > >> fixed-regulator. We had instances like 2430SDP ethernet where... umm..= =2E we > >> originally missed describing ethernet supply and boom, one fine mornin= g, no > >> more nfs filesystem - I mean, it is a one off scenario there, but desc= ribing > >> regulators helps us atleast understand the power tree of the board a l= ittle > >> better. > >> > >> Again, no strong opinions on my side, it is a good thing to do is all > >> I feel about it. > >=20 > > you mean something like: > >=20 > > V5_0D: fixedregulator@0 { > > compatible =3D "regulator-fixed"; > > regulator-name =3D "V5_0D"; > > regulator-min-microvolt =3D <5000000>; > > regulator-max-microvolt =3D <5000000>; > > regulator-boot-on; > > regulator-always-on; > > vin-supply =3D <&dcdc4>; > > }; > >=20 > > VBUS_USB: fixedregulator@1 { > > compatible =3D "regulator-fixed"; > > regulator-name =3D "VBUS_USB"; > > regulator-min-microvolt =3D <5000000>; > > regulator-max-microvolt =3D <5000000>; > > regulator-boot-on; > > regulator-always-on; > > vin-supply =3D <&V5_0D>; > > }; > >=20 > > I can add that, but note that it's *solely* to make sysfs look nice. And > > if that's the case, most likely *every* DTS file in tree today as > > incomplete. OTOH, I really consider this to be hugely unnecessary > > because of the fact that board will turn off if 3v3 (dcdc4) is disabled. > >=20 >=20 >=20 > Yes - something along those lines - Again, no strong opinions on my > side for these - just that it is a good thing to model in and may help > drivers where can use the awareness. if you ask me, it's just two extra instances of the fixed regulator driver for a really marginal added benefit. --=20 balbi --huq684BweRXVnRxX Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJTomDWAAoJEIaOsuA1yqREKTQP/jJOrzVZws/wKmelIZPjLwT0 NPfngr+cp68SyuYmdtXrZ0SVbgk3XJq3iVHsXEyXeHXCTqJVbBQk1ceAsX0nxURV msc4AnOZyuVhvIVmTA++DDPf7PUVkffrYPaww8eoxD4IOVjc6kMsW1WEtW3K7q9U S5a016+BnIWZ75U1O01P9Oz09YVsNJj89rI0En+ZtJgjnkLeXi3eJTqdiJH2liij cAxc2wlxBm8QWtP2DnTW6fR0g3FVR1pQOdBbzcj6avDrSonzuR6CCLAKEtMEgOrp xqLs+Lq60OaRzuI5f7Y58IdtNDOcNQQUglJGdaoeMkDbIC+qRmFyebAFyFfilIB/ utvgyMqYNdwnqx+WFlwR6YMlLeCncRMmdwO4E/dmkQnZAwv6wOi+5gZMLkS6xuPO HueNnZQfjkowb4U0XBfyTDplLtZzFQnAZeNL3ahyuXwb3Q74dHSMNY0tWheYLsui KlQY4efhc70mAkeA5MaOpmRAexh761G158QlH5jn0yAwGr3EEsP5XyIBsIuHo/XZ s+E96aevpHLVBIFkFcX5UTdpeshbZANlDgNxQXu+GBBC6fRGRg4EsKvwkhRYivyV vu6egYj7gz8DcfYqNMP4pEbIKhcMZiDLe2VHLzciEuljucxsh3mXWmZjISDos+bq HFKds2WZVkMpz93Ie/IF =L2TR -----END PGP SIGNATURE----- --huq684BweRXVnRxX--