From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161159AbbKFKa7 (ORCPT ); Fri, 6 Nov 2015 05:30:59 -0500 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:49584 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1032984AbbKFKa5 (ORCPT ); Fri, 6 Nov 2015 05:30:57 -0500 Date: Fri, 6 Nov 2015 10:30:32 +0000 From: Mark Brown To: "Opensource [Adam Thomson]" Cc: Liam Girdwood , Jaroslav Kysela , Takashi Iwai , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , "alsa-devel@alsa-project.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Support Opensource Message-ID: <20151106103032.GY18409@sirena.org.uk> References: <20151105145856.GM18409@sirena.org.uk> <2E89032DDAA8B9408CB92943514A0337D460C91F@SW-EX-MBX01.diasemi.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="B7FF+pnjRCrp0ISR" Content-Disposition: inline In-Reply-To: <2E89032DDAA8B9408CB92943514A0337D460C91F@SW-EX-MBX01.diasemi.com> X-Cookie: Put your trust in those who are worthy. User-Agent: Mutt/1.5.24 (2015-08-30) X-SA-Exim-Connect-IP: 217.140.96.141 X-SA-Exim-Mail-From: broonie@sirena.org.uk Subject: Re: [PATCH 1/2] ASoC: da7218: Add bindings documentation for DA7218 audio 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 --B7FF+pnjRCrp0ISR Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thu, Nov 05, 2015 at 05:59:29PM +0000, Opensource [Adam Thomson] wrote: > On November 05, 2015 14:59, Mark Brown wrote: > > > +- dlg,ldo-lvl : Required internal LDO voltage (mV) level > > > + [<1050>, <1100>, <1200>, <1400>] > > Why would this ever be anything other than the minimum voltage, and > > might we not want to vary it at runtime? > Normally you are correct and you'll want minimum voltage for the digital engine > but there may be the possibility for certain platform scenarios that to meet > timings a higher voltage is required. Would prefer to leave this in in case it > is required in the future. As a side, the default setting is the lowest voltage, > if this binding is not provided. That doesn't make a huge degree of sense - your non-specific "certain platform scenarios" are almost certainly going to be DVFS things where you need to boost the voltage of the LDO when the device needs to operate at particularly high frequencies in which case the driver really ought to just manage the voltage appropriately as required (ideally only boosting it at the times where the extra load exists). Unless you can be more specific about what the intended use is this just doesn't seem like something we should be specifying in DT. > > These look like DSP coefficients which I would therefore expect to be > > configurable at runtime via a binary control rather than specified in > > the DT - why are they in the DT? > The expectation was these would be set once and left for a platform, which is > why I added them to the DT. However there's no reason they couldn't be moved > to binary control. Having looked at other codecs, I assume SND_SOC_BYTES* would > be the preferred method for setting this kind of data? Yes. --B7FF+pnjRCrp0ISR Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJWPIFHAAoJECTWi3JdVIfQt08H/0WkndFHZtEZogwh1UBOZbkX J7HuBti0sirozDtkzAc/rq2Su8x/yEjtnFMGFieBzT0vaHJtN3AW2g1R+PKw2Hxg gAfaFEZ4diZX4SPS7SPPQuDPi7tGt9leJ3u3bpKMsFMthaj2UUOgKJp+2246D2QM uUITga79ecLlPorHVacB5rBrU+0dkIbPVE0dN4E+MdOHT4x1q5B2yL6yzALT3hIx AFTcnQ65Cvs5wo2dHgryvcaK7YdKzeLOn6ZGJhu8Ce528tK7Uw3zD9jc4fMtGJpi 8znVeLsNKX/C7cBoP6Ngk/PvLA82IDK75tJOyl/a0263fx+v7AbXkbSYN+BjMi0= =y5Uc -----END PGP SIGNATURE----- --B7FF+pnjRCrp0ISR--