From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [203.10.76.45]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.ozlabs.org", Issuer "CA Cert Signing Authority" (verified OK)) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4801CB6F34 for ; Sun, 14 Jun 2009 01:40:25 +1000 (EST) MIME-Version: 1.0 In-Reply-To: <20090611201545.GA15942@oksana.dev.rtsoft.ru> References: <20090611201545.GA15942@oksana.dev.rtsoft.ru> From: Grant Likely Date: Sat, 13 Jun 2009 09:40:02 -0600 Message-ID: Subject: Re: [PATCH] sdhci: Add support for hosts that are only capable of 1-bit transfers To: Anton Vorontsov Content-Type: text/plain; charset=ISO-8859-1 Cc: linuxppc-dev@ozlabs.org, Pierre Ossman , devicetree-discuss@ozlabs.org, sdhci-devel@lists.ossman.eu List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, Jun 11, 2009 at 2:15 PM, Anton Vorontsov wrote: > Some hosts (hardware configurations, or particular SD/MMC slots) may > not support 4-bit bus. For example, on MPC8569E-MDS boards we can > switch between serial (1-bit only) and nibble (4-bit) modes, thought > we have to disable more peripherals to work in 4-bit mode. > > Along with some small core changes, this patch modifies sdhci-of > driver, so that now it looks for "mode" property in the device-tree. > > Signed-off-by: Anton Vorontsov > --- > > Pierre, I'm not sure if a quirk would be appropriate here. If so, > I can redo the patch with FORCE_1_BIT_DATA quirk. > > Thanks, > > =A0Documentation/powerpc/dts-bindings/fsl/esdhc.txt | =A0 =A02 ++ > =A0drivers/mmc/host/sdhci-of.c =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 = =A0| =A0 =A07 +++++++ > =A0drivers/mmc/host/sdhci-pci.c =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 |= =A0 =A01 + > =A0drivers/mmc/host/sdhci.c =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 = =A0 | =A0 =A02 +- > =A04 files changed, 11 insertions(+), 1 deletions(-) > > diff --git a/Documentation/powerpc/dts-bindings/fsl/esdhc.txt b/Documenta= tion/powerpc/dts-bindings/fsl/esdhc.txt > index 5093ddf..298b865 100644 > --- a/Documentation/powerpc/dts-bindings/fsl/esdhc.txt > +++ b/Documentation/powerpc/dts-bindings/fsl/esdhc.txt > @@ -10,6 +10,8 @@ Required properties: > =A0 - interrupts : should contain eSDHC interrupt. > =A0 - interrupt-parent : interrupt source phandle. > =A0 - clock-frequency : specifies eSDHC base clock frequency. > + =A0- mode : specifies eSDHC mode, valid values are: "1-bit" and "4-bit"= . > + =A0 =A0If mode is unspecified, then 4-bit mode is assumed. In light of Pierre's comment that 4-bit is mandatory and this is a deviation, perhaps it would be better to define an empty property to indicate that only 1-bit transfers work. Maybe something along the lines of "sdhc-1-bit-only"? g. --=20 Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd.