From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Ball Subject: Re: [PATCH v2 1/5] mmc: host: sdhci-s3c: Add broken-voltage DT property for broken voltage quirk Date: Wed, 19 Sep 2012 06:24:46 -0400 Message-ID: References: <1346748609-11115-1-git-send-email-t.figa@samsung.com> <1346748609-11115-2-git-send-email-t.figa@samsung.com> <1587150.uFGRdL0s8e@amdc1227> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1587150.uFGRdL0s8e@amdc1227> (Tomasz Figa's message of "Wed, 19 Sep 2012 12:13:14 +0200") Sender: linux-samsung-soc-owner@vger.kernel.org To: Tomasz Figa Cc: linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kyungmin.park@samsung.com, jy0922.shim@samsung.com, kgene.kim@samsung.com, thomas.abraham@linaro.org, Ben Dooks , linux-mmc@vger.kernel.org List-Id: linux-mmc@vger.kernel.org Hi Tomasz, On Wed, Sep 19 2012, Tomasz Figa wrote: > Hi Chris, > > On Wednesday 19 of September 2012 01:42:01 Chris Ball wrote: >> On Tue, Sep 04 2012, Tomasz Figa wrote: >> > Some boards use fixed voltage regulator for vmmc supply (e.g. for eMMC >> > memories). MMC_CAP2_BROKEN_VOLTAGE must be enabled for them to operate >> > correctly. >>> >> Is there a reason we can't make this a property on the regulator instead? > > Is there a reason we can't make this a property of the mmc subsystem? ;) > > Now, seriously, could you elaborate on this a bit more? Do you mean that a > regulator should provide a dummy set voltage operation that would accept > any voltage? Sorry for the terseness. It seems like we're encoding exactly the same information twice in two different subsystems -- I don't see the point, so I'd like to think about how we could do better. For example, if we're only concerned about fixed regulators, could we just detect a fixed regulator in the driver and avoid the failing call to regulator_set_voltage() directly, without needing to go via this capability? Seems like the capability doesn't tell us anything we couldn't already have known. Thanks, - Chris. -- Chris Ball One Laptop Per Child