From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: ASoC: new ac97 bus and codec clock Date: Wed, 27 Jun 2018 12:23:35 +0100 Message-ID: <20180627112335.GI1779@sirena.org.uk> References: <87lgbdqixh.fsf@belgarion.home> <20180619150204.GF11230@sirena.org.uk> <8736xhqzmn.fsf@belgarion.home> <87y3f9peyb.fsf@belgarion.home> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============3770734897306970529==" Return-path: Received: from heliosphere.sirena.org.uk (heliosphere.sirena.org.uk [172.104.155.198]) by alsa0.perex.cz (Postfix) with ESMTP id 5EF6E267610 for ; Wed, 27 Jun 2018 13:23:39 +0200 (CEST) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Rob Herring Cc: Frank Rowand , Linux-ALSA , Robert Jarzmik , Daniel Mack List-Id: alsa-devel@alsa-project.org --===============3770734897306970529== Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="ZOudaV4lSIjFTlHv" Content-Disposition: inline --ZOudaV4lSIjFTlHv Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Jun 20, 2018 at 11:16:15AM -0600, Rob Herring wrote: > Does AC97 specify a common programming model? That's were a common > compatible is used (though experience has proven things like > "generic-ehci" are don't work). Yes, there is a standard register interface which all AC'97 CODECs implemented and which does work effectively for drivers that only use that. Devices can offer extensions which do need specific drivers, and there are ID registers which can be used to enumerate. However one of the things that some of the devices targetted at embedded systems do is offer non-standard clocking features that need some configuration during initialization (and may need to work with input clocks too) which complicates things, especially in the context of DT. --ZOudaV4lSIjFTlHv Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAlszc7cACgkQJNaLcl1U h9BahQf/ZczIHdyfC6r/Khks82FtXbEYPr1hq25SF8ExEQLpZMJXNMS4M2hFFPNV EgZknbfoQAjMlVYijJKos61wcDihhzi1BH8KW6KpM6mJzEjRpgSQjmMHfIlEmJtH 4vsdpbvrwwSwdmPNWWduGnE4zNNzdzxBbHPaQvol7dAhxXNTawrvSolj/B9fv3Sj mal8w/k2Kt1zk3f34A/VfBGxTmTcpFH/pvxEjCEhJZgQIYY3SlTDCa6CG9qtfbEO 6XcRVIwsOlQbYCGUBDK+d8gBQMuJ6uLpFu86IXob7bapETbHTk1Ve1DsWkSQHW5F 9Qh2wU2xEVa6kEJKwgbh6YyQo1J2Kw== =I1Py -----END PGP SIGNATURE----- --ZOudaV4lSIjFTlHv-- --===============3770734897306970529== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline --===============3770734897306970529==--