Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751895AbaLCUDv (ORCPT ); Wed, 3 Dec 2014 15:03:51 -0500 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:47449 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750862AbaLCUDt (ORCPT ); Wed, 3 Dec 2014 15:03:49 -0500 Date: Wed, 3 Dec 2014 20:03:07 +0000 From: Mark Brown To: Sonny Rao Cc: Jianqun Xu , Liam Girdwood , perex@perex.cz, tiwai@suse.de, Heiko =?iso-8859-1?Q?St=FCbner?= , "linux-arm-kernel@lists.infradead.org" , alsa-devel@alsa-project.org, "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" , linux-rockchip@lists.infradead.org Message-ID: <20141203200307.GM7712@sirena.org.uk> References: <1417531766-29669-1-git-send-email-jay.xu@rock-chips.com> <1417591118-18695-1-git-send-email-jay.xu@rock-chips.com> <1417591118-18695-3-git-send-email-jay.xu@rock-chips.com> <20141203192024.GL7712@sirena.org.uk> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="gz7Dl29304g/DuvU" Content-Disposition: inline In-Reply-To: X-Cookie: Celebrity voices impersonated. User-Agent: Mutt/1.5.23 (2014-03-12) X-SA-Exim-Connect-IP: 94.175.94.161 X-SA-Exim-Mail-From: broonie@sirena.org.uk Subject: Re: [PATCH v2 2/2] ASoC: rockchip: i2s: add support for grabbing output clock to codec X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on mezzanine.sirena.org.uk) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --gz7Dl29304g/DuvU Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Dec 03, 2014 at 11:38:13AM -0800, Sonny Rao wrote: > On Wed, Dec 3, 2014 at 11:20 AM, Mark Brown wrote: > > I would expect that the clock for the CODEC should be managed by the > > CODEC if at all possible - that seems more logical than having the CPU > > I2S controller request and manage it if it's a separate clock. Why add > > this to the CPU side driver? > This output clock has a mux and can either be a fixed 12Mhz output or > can be derived from the same fractional divider which drives the i2s > block. I thought it was simpler to keep them all the same, but need > to put ownership in the i2s in anticipation of the i2s driver setting > it's own clock rate. > If you think this is an implementation detail and this output clock > should just be owned by the codec driver, even though I'm guessing it > will just have to be the same as i2s, then I think we can drop this > and make sure simple card (or whatever other codec driver) claims this > clock. simple-card obviously isn't a CODEC driver... For generality I think the clock does need to be exposed to the CODEC driver, otherwise this will work differently to how other systems are working and we can't substitute in a different clock on the CODEC side so easily if it doesn't happen to use the output from the I2S block. --gz7Dl29304g/DuvU Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBAgAGBQJUf2x6AAoJECTWi3JdVIfQor4H/R8QlkqfCU1Ht8Ka0ICFucYS I79180Ndm9Ulbi7VE7FusGljeVINcXw1GWWw34nkG5zjGVoFlVY3flV7ZNbfOlyM 5LQHM8j11BUqQB7WQ1AGtBJ3XTB3yO74MXMva4zCufePubbG72HNgn1CdkvgMXT5 Ty5JrgwWMBxeLZ77xrt4zVZMlGSNPgk/fKGiGxE8qb82kHMZYeodDRXnU/GR4LHC UPGDFvzILh7eZXGUKtmG33+YRay44JLW3gfLZd27iDoPmxoVCNzvS7CIn1yUls0I cQbklM9JMBlt/bjzWs8g9aOFeqZ8IKzwGzMlqTrWcgwEpW2PXpBhmHxFlj9hUnw= =Bt5J -----END PGP SIGNATURE----- --gz7Dl29304g/DuvU-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/