Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423525Ab3FUROD (ORCPT ); Fri, 21 Jun 2013 13:14:03 -0400 Received: from ns.lynxeye.de ([87.118.118.114]:50037 "EHLO lynxeye.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1423404Ab3FUROB (ORCPT ); Fri, 21 Jun 2013 13:14:01 -0400 X-Greylist: delayed 638 seconds by postgrey-1.27 at vger.kernel.org; Fri, 21 Jun 2013 13:14:00 EDT Message-ID: <1371834306.1524.7.camel@tellur> Subject: Re: [PATCH] ARM:tegra20-colibri-512.dts: Change tristate status for i2c pinmux From: Lucas Stach To: Stephen Warren Cc: Anna-Maria Gleixner , linux-tegra@vger.kernel.org, Joseph Lo , linux-kernel@vger.kernel.org Date: Fri, 21 Jun 2013 19:05:06 +0200 In-Reply-To: <51C47E41.6050609@wwwdotorg.org> References: <51C47E41.6050609@wwwdotorg.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.8.3 (3.8.3-1.fc19) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2002 Lines: 51 Am Freitag, den 21.06.2013, 10:24 -0600 schrieb Stephen Warren: > On 06/20/2013 03:08 PM, Anna-Maria Gleixner wrote: > > The nvidia,tristate entry for the pinmux of i2c1 an i2c3 was set to > > tristate. This results in non working i2c, because the i2c pins are > > not actively driven. Set the entries to "driven". > > Lucas, can you please comment on this patch? It sounds correct to me, > but I would have assumed you'd tested I2C already when you wrote the > original DT? > This is a NACK from me. For robustness reasons all pins/busses not actually used on the Colibri module itself are tristated in order to avoid any invalid configurations when placed on a baseboard. Baseboards using particular busses should untristate those pins in their respective dts. So if this change is about iris, I would be ok with enabling i2c1, as this is actually routed on this baseboard, but not i2c3. Regards, Lucas > Oh actually, now that I look further, I see that tegra20-iris-512.dts > includes this file, and overrides some of the tristate values there. > What's the thinking behind that, and does this patch fit into it? > > > diff --git a/arch/arm/boot/dts/tegra20-colibri-512.dtsi > > > nvidia,pins = "rm"; > > nvidia,function = "i2c1"; > > nvidia,pull = <0>; > > - nvidia,tristate = <1>; > > + nvidia,tristate = <0>; > > }; > > i2c3 { > > nvidia,pins = "dtf"; > > nvidia,function = "i2c3"; > > nvidia,pull = <0>; > > - nvidia,tristate = <1>; > > + nvidia,tristate = <0>; > > }; > > i2cddc { > > nvidia,pins = "ddc"; > -- 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/