From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: [PATCH] i2c: designware: deduce speed mode from device tree setting Date: Wed, 20 Aug 2014 07:36:18 -0500 Message-ID: <20140820123617.GB1373@katana> References: <1408479529-24249-1-git-send-email-atull@opensource.altera.com> <20140820092257.GA21174@leverpostej> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="hQiwHBbRI9kgIhsi" Return-path: Content-Disposition: inline In-Reply-To: <20140820092257.GA21174@leverpostej> Sender: linux-kernel-owner@vger.kernel.org To: Mark Rutland Cc: "atull@opensource.altera.com" , "baruch@tkos.co.il" , "mika.westerberg@linux.intel.com" , "grant.likely@linaro.org" , "robh+dt@kernel.org" , "skuribay@pobox.com" , "Romain.Baeriswyl@abilis.com" , "rafael.j.wysocki@intel.com" , "alan@linux.intel.com" , "linux-i2c@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" , "delicious.quinoa@gmail.com" , "dinguyen@opensource.altera.com" , "yvanderv@opensource.altera.com" List-Id: devicetree@vger.kernel.org --hQiwHBbRI9kgIhsi Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > > + > > + ret =3D of_property_read_u32(pdev->dev.of_node, > > + "clock-frequency", &bus_rate); > > + if (!ret && (bus_rate <=3D 100000)) > > + speed =3D DW_IC_CON_SPEED_STD; >=20 > This looks a bit odd. >=20 > If the device only supports two particular speeds why do we accept any > other speed in the clock-frequency property? "clock-frequency" is the default binding for specifying i2c bus speeds today. Some controllers can be programmed to do various speeds, some can only do a set of fixed values. > Surely we should at least warn that something was off? Yes, I was going to say the same until Romain's old patch showed up which does that. Thanks, Wolfram --hQiwHBbRI9kgIhsi Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJT9JZBAAoJEBQN5MwUoCm22TsQAISfSofiMFAxoAXGsj+R5SPI 3NPq6TSgjwv/VrrB5PjiSE+qt3qbcaHLxAA1UU33mMA5Zj9QT+1LCFZ0v3Kv6TBl XIcUp7JVIQJ343V/XgLiYKPV99uRCM+BulRE5zurF+p2QRjOcV66rUAjdqCYmASW ItRNxxEIcvrM4vBGzhWHRDe4iPl4D6J2QNxZaUE9gmdkbUIiTYF3vasf/5+eBaNx 3YodLSng+HSirXkVKNAi5vCYvaNu3Rc6dTsOHLlI5Bn0xtkiTVI8zvQ49tR+3uJQ Ad8VBZuPhzyaALwdqiqM+kDJQW3uYoQtFeQsZJVEZz9SwX/Oo8xRKdB+zP4Pgu67 HQKo8HmwzazlnfNfQs4LxsiR12RvnmGIlmS+3S3l55dK0J1Jex1qHZH23YT5Cseo rO9Jc356lsZK/E2gCgAigw9CuSvuHgg1vgtqMjTBj+64LfphnWFrsUzlrAsza+35 KfdkROGypxkCMXtjHrOsCWMZ2XY6Of/Qxa76iofV+7bTc5SD5MT56d9o1CJiSkCB QrDqDcDwaq0alzJWwNLIHe/OLJolSZi2jyNkYqhH1Xkf+K8JplmkxQe3bHBj++DU YS3hfPAe3+XZ6sNrIJaC8vQWCMNkc0rOTztJNLszVIBPoyVCqom0+VqXt4nY39D7 Z8LLOaVtvFzCoWdSiJe3 =iqcS -----END PGP SIGNATURE----- --hQiwHBbRI9kgIhsi--