From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH 0/5] MMC: mmci: Provide bindings for Device Tree Date: Fri, 16 Mar 2012 12:36:35 +0000 Message-ID: <201203161236.36088.arnd@arndb.de> References: <1331734803-17954-1-git-send-email-lee.jones@linaro.org> <201203152058.31398.arnd@arndb.de> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from moutng.kundenserver.de ([212.227.126.187]:60193 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750838Ab2CPMgj (ORCPT ); Fri, 16 Mar 2012 08:36:39 -0400 In-Reply-To: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Linus Walleij Cc: Mark Brown , Per Forlin , niklas.hernaeus@linaro.org, linux-mmc@vger.kernel.org, cjb@laptop.org, Lee Jones , linux-arm-kernel@lists.infradead.org On Friday 16 March 2012, Linus Walleij wrote: > On Thu, Mar 15, 2012 at 9:58 PM, Arnd Bergmann wrote: > > [Per] > >> The stedma40 filter function is not really specific for ux500. ux500 > >> use stedma40 but it should be possible to replace this DMA.IP with > >> some other DMA-controller. This is board specific configuration. You > >> should not need to change the mmci-driver just because the dma-driver > >> has changed, right? > >> Or will the board-configuration now be placed in mmci-ux500? > > > > Right, the DMA configuration does not really belong in there, but > > the voltage setup might (unless we convert that to the regulator > > setup). > > The voltage to power the card is already using the regulator > framework with the MMC-specific helpers in the MMCI driver. > > But I guess you're after modelling the levelshifter as a regulator? > > Basically the level shifter is a separate device has two voltage > inputs A and B (from other regulators) that is controlled by a > simple GPIO to select voltage A or B to drive the signals to > the card. > > That could probably be modelled as a regulator with two > volategs for sure, but then we should maybe create a more > generic "struct level_shifter_regulator" (or whatever) for the > concept as a whole. Ok, thanks for the explanation. > Let's page Mark about what to do with levelshifters and whether > they are regulators of sorts in his book. It does sound appealing, especially because this one could be done completely generically by defining a regulator that has a bunch of other regulators as well as a set of gpio lines as inputs and one output that can be used in other devices. We would probably only use this one together with device tree then. Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Fri, 16 Mar 2012 12:36:35 +0000 Subject: [PATCH 0/5] MMC: mmci: Provide bindings for Device Tree In-Reply-To: References: <1331734803-17954-1-git-send-email-lee.jones@linaro.org> <201203152058.31398.arnd@arndb.de> Message-ID: <201203161236.36088.arnd@arndb.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Friday 16 March 2012, Linus Walleij wrote: > On Thu, Mar 15, 2012 at 9:58 PM, Arnd Bergmann wrote: > > [Per] > >> The stedma40 filter function is not really specific for ux500. ux500 > >> use stedma40 but it should be possible to replace this DMA.IP with > >> some other DMA-controller. This is board specific configuration. You > >> should not need to change the mmci-driver just because the dma-driver > >> has changed, right? > >> Or will the board-configuration now be placed in mmci-ux500? > > > > Right, the DMA configuration does not really belong in there, but > > the voltage setup might (unless we convert that to the regulator > > setup). > > The voltage to power the card is already using the regulator > framework with the MMC-specific helpers in the MMCI driver. > > But I guess you're after modelling the levelshifter as a regulator? > > Basically the level shifter is a separate device has two voltage > inputs A and B (from other regulators) that is controlled by a > simple GPIO to select voltage A or B to drive the signals to > the card. > > That could probably be modelled as a regulator with two > volategs for sure, but then we should maybe create a more > generic "struct level_shifter_regulator" (or whatever) for the > concept as a whole. Ok, thanks for the explanation. > Let's page Mark about what to do with levelshifters and whether > they are regulators of sorts in his book. It does sound appealing, especially because this one could be done completely generically by defining a regulator that has a bunch of other regulators as well as a set of gpio lines as inputs and one output that can be used in other devices. We would probably only use this one together with device tree then. Arnd