From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [PATCH 3/3] ARM: dt: tegra: paz00: add regulators Date: Mon, 25 Jun 2012 13:07:45 +0200 Message-ID: <20120625110745.GB11710@avionic-0098.mockup.avionic-design.de> References: <1340406842-27135-1-git-send-email-swarren@wwwdotorg.org> <4127323.noaajNecru@ax5200p> <20120624123151.GZ4037@opensource.wolfsonmicro.com> <27366523.LjLfRK1TqH@ax5200p> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="ghzN8eJ9Qlbqn3iT" Return-path: Content-Disposition: inline In-Reply-To: <27366523.LjLfRK1TqH@ax5200p> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Marc Dietrich Cc: Mark Brown , Stephen Warren , Olof Johansson , Colin Cross , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Stephen Warren List-Id: linux-tegra@vger.kernel.org --ghzN8eJ9Qlbqn3iT Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Jun 24, 2012 at 03:27:42PM +0200, Marc Dietrich wrote: > On Sunday 24 June 2012 13:31:51 Mark Brown wrote: > > On Sun, Jun 24, 2012 at 02:01:58PM +0200, Marc Dietrich wrote: > > > On Sunday 24 June 2012 12:03:06 Mark Brown wrote: > > > > > > + regulator-name =3D "+3.3vs_l= do0"; > > > > > > + regulator-max-microvolt =3D <3300000>; > > > >=20 > > > > This is one example, it looks like the rail needs to be fixed to 3.= 3V. > > >=20 > > > I think nowhere in the code a regulator (beside sm*) is programmed to= some > > > different value that the maximum given here (this is not the maximum = the > > > regulator can provide). I never understood why the kernel code always= sets > > > the regulator to the maximum value if no other value was specified. I= MHO, > > > there should be some initial value, e.g. regulator-default-microvolt,= as > > > the original driver (from 2.6.32 ages) did. This way the maximum value > > > can be set > > That's *never* been in mainline, and nobody even bothered trying to > > submit it. >=20 > which was the best thing to do ;-) >=20 > > > to the hw limits, but maybe this is a bit dangerous. > >=20 > > One of two things should be happening. Either a single voltage is > > specified (in which case that voltage will be configured in the >=20 > I'm not an expert on this, but it seems to me that only sm0 and sm1 shoul= d be=20 > changeable (and some rail called vdd_aon, which seems to be ldo2 in case = of=20 > paz00 connected to the rtc). So, all others can be constant voltage. Mayb= e=20 > Stephen can comment on the actual requirements (also for the other boards= =20 > which may have similar layout). I can confirm that at least for ldo0 the value needs to be fixed. I did in fact post a patch back in February that was needed to fix PCIe on Harmony. I also sat down with one of our hardware engineers and worked through the list and wrote down the requirements for Harmony. I need to check where our notes have gone, though. Thierry --ghzN8eJ9Qlbqn3iT Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) iQIcBAEBAgAGBQJP6EaBAAoJEN0jrNd/PrOhwskP/jNj8wYMCbaHhemTRFHihUGe NBPk/SvpvJ5ldA25+cn+3Nvr6v94/v0ZGdyJfQtdnwDa1QNa4vllyzdw/zgygb/K 5jivLMTJV7ReVBBeUpZdPAcxxghXfhxn3K/+/69yV9ToeCZDcs/SEe6kElrfKD/q QV+/7PsC26uII0tczZzUwto0lxRX9cEzYmnp8wjcyR6CCAx7BZg956sJAHHPgWmc rHFOqcS9pxCibk1/nYzE0nHtSAcahc18bSgZh6ry9ihZux6lcOXfhNnFEhJGns0n TJ5NwxFNBIx+eXMJY/sb4FjEe5rQC/jQqhXZ17sIBNLU2ajwy09loaJIF2mfO9Zl NzXx3IhSizDGnGDfZ+VGo45Anz95ySpCBdeAAOF8+qW5Ji1p0tg6wDvnVnbeSLGz P3qt+eXotu9cCDkmbj/RXwYvpFD7QKjO0727IV3dyQftuA5pEw8pSHKI0mRSqy0m hDxc7OCNuG1O8FyfBpYJUYdrKzSMAIdNkwJqdkM/yzWBcsHtddnXLqqaAj/Rh86i QrmVekKgPIQTRQ5d3C5u6eGXxJe3O42OjZcwWW56Sit2JfH4BL84taTHiBU7yL/L qrwRyrBkJpqP5qlDrvvCGQK4bRr7rc2AGpvz6zeD/+EXJnczjm84iPfLRvU1C4Jf G4DJXAXS6qIFD3jhdLfh =ifEO -----END PGP SIGNATURE----- --ghzN8eJ9Qlbqn3iT-- From mboxrd@z Thu Jan 1 00:00:00 1970 From: thierry.reding@avionic-design.de (Thierry Reding) Date: Mon, 25 Jun 2012 13:07:45 +0200 Subject: [PATCH 3/3] ARM: dt: tegra: paz00: add regulators In-Reply-To: <27366523.LjLfRK1TqH@ax5200p> References: <1340406842-27135-1-git-send-email-swarren@wwwdotorg.org> <4127323.noaajNecru@ax5200p> <20120624123151.GZ4037@opensource.wolfsonmicro.com> <27366523.LjLfRK1TqH@ax5200p> Message-ID: <20120625110745.GB11710@avionic-0098.mockup.avionic-design.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sun, Jun 24, 2012 at 03:27:42PM +0200, Marc Dietrich wrote: > On Sunday 24 June 2012 13:31:51 Mark Brown wrote: > > On Sun, Jun 24, 2012 at 02:01:58PM +0200, Marc Dietrich wrote: > > > On Sunday 24 June 2012 12:03:06 Mark Brown wrote: > > > > > > + regulator-name = "+3.3vs_ldo0"; > > > > > > + regulator-max-microvolt = <3300000>; > > > > > > > > This is one example, it looks like the rail needs to be fixed to 3.3V. > > > > > > I think nowhere in the code a regulator (beside sm*) is programmed to some > > > different value that the maximum given here (this is not the maximum the > > > regulator can provide). I never understood why the kernel code always sets > > > the regulator to the maximum value if no other value was specified. IMHO, > > > there should be some initial value, e.g. regulator-default-microvolt, as > > > the original driver (from 2.6.32 ages) did. This way the maximum value > > > can be set > > That's *never* been in mainline, and nobody even bothered trying to > > submit it. > > which was the best thing to do ;-) > > > > to the hw limits, but maybe this is a bit dangerous. > > > > One of two things should be happening. Either a single voltage is > > specified (in which case that voltage will be configured in the > > I'm not an expert on this, but it seems to me that only sm0 and sm1 should be > changeable (and some rail called vdd_aon, which seems to be ldo2 in case of > paz00 connected to the rtc). So, all others can be constant voltage. Maybe > Stephen can comment on the actual requirements (also for the other boards > which may have similar layout). I can confirm that at least for ldo0 the value needs to be fixed. I did in fact post a patch back in February that was needed to fix PCIe on Harmony. I also sat down with one of our hardware engineers and worked through the list and wrote down the requirements for Harmony. I need to check where our notes have gone, though. Thierry -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 836 bytes Desc: not available URL: