Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755052Ab3CEXsz (ORCPT ); Tue, 5 Mar 2013 18:48:55 -0500 Received: from mail-pb0-f42.google.com ([209.85.160.42]:50588 "EHLO mail-pb0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753277Ab3CEXsy (ORCPT ); Tue, 5 Mar 2013 18:48:54 -0500 MIME-Version: 1.0 In-Reply-To: <1360957573-864-2-git-send-email-dianders@chromium.org> References: <1360887677-20758-1-git-send-email-dianders@chromium.org> <1360957573-864-1-git-send-email-dianders@chromium.org> <1360957573-864-2-git-send-email-dianders@chromium.org> From: Naveen Krishna Ch Date: Wed, 6 Mar 2013 08:48:33 +0900 Message-ID: Subject: Re: [PATCH v3 2/3] ARM: dts: Add i2c-arbitrator bus for exynos5250-snow To: Doug Anderson Cc: Wolfram Sang , Simon Glass , Naveen Krishna Chatradhi , Grant Likely , Yuvaraj Kumar , Ben Dooks , u.kleine-koenig@pengutronix.de, Mark Brown , Girish Shivananjappa , bhushan.r@samsung.com, sreekumar.c@samsung.com, Prashanth G , Olof Johansson , Daniel Kurtz , Grant Grundler , Russell King , Kukjin Kim , Rahul Sharma , Thomas Abraham , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3770 Lines: 107 On 16 February 2013 04:46, Doug Anderson wrote: > We need to use the i2c-arbitrator to talk to any of the devices on i2c > bus 4 on exynos5250-snow so that we don't confuse the embedded > controller (EC). Add the i2c-arbitrator to the device tree. As we > add future devices (keyboard, sbs, tps65090) we'll add them on top of > this. > > The arbitrated bus is numbered 104 simply as a convenience to make it > easier for people poking around to guess that it might have something > to do with the physical bus 4. > > The addition is split between the cros5250-common and the snow device > tree file since not all cros5250-class devices use arbitration. > > Signed-off-by: Doug Anderson Tested-by: Naveen Krishna Chatradhi The patch set [v3] is tested on snow with test case which uses i2c-4 from both EC and AP side continuously for a more than a couple of minutes. > --- > Changes in v3: None > Changes in v2: > - Use new device tree property names / compatible string. > - Include that the GPIOs for arbitration are active low. > > arch/arm/boot/dts/cros5250-common.dtsi | 5 ++++- > arch/arm/boot/dts/exynos5250-snow.dts | 25 +++++++++++++++++++++++++ > 2 files changed, 29 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/boot/dts/cros5250-common.dtsi b/arch/arm/boot/dts/cros5250-common.dtsi > index 46c0980..f451375 100644 > --- a/arch/arm/boot/dts/cros5250-common.dtsi > +++ b/arch/arm/boot/dts/cros5250-common.dtsi > @@ -58,7 +58,10 @@ > }; > > i2c@12CA0000 { > - status = "disabled"; > + samsung,i2c-sda-delay = <100>; > + samsung,i2c-max-bus-freq = <66000>; > + gpios = <&gpa2 0 3 3 0>, > + <&gpa2 1 3 3 0>; > }; > > i2c@12CB0000 { > diff --git a/arch/arm/boot/dts/exynos5250-snow.dts b/arch/arm/boot/dts/exynos5250-snow.dts > index 17dd951..d2d4b48 100644 > --- a/arch/arm/boot/dts/exynos5250-snow.dts > +++ b/arch/arm/boot/dts/exynos5250-snow.dts > @@ -16,6 +16,10 @@ > model = "Google Snow"; > compatible = "google,snow", "samsung,exynos5250"; > > + aliases { > + i2c104 = &i2c_104; > + }; > + > gpio-keys { > compatible = "gpio-keys"; > > @@ -29,6 +33,27 @@ > }; > }; > > + i2c-arbitrator { > + compatible = "i2c-arbitrator-cros-ec"; > + #address-cells = <1>; > + #size-cells = <0>; > + > + i2c-parent = <&{/i2c@12CA0000}>; > + > + ap-claim-gpio = <&gpf0 3 1 0x10000 0>; > + ec-claim-gpio = <&gpe0 4 0 0x10003 0>; > + slew-delay-us = <10>; > + wait-retry-us = <3000>; > + wait-free-us = <50000>; > + > + /* Use ID 104 as a hint that we're on physical bus 4 */ > + i2c_104: i2c@0 { > + reg = <0>; > + #address-cells = <1>; > + #size-cells = <0>; > + }; > + }; > + > /* > * On Snow we've got SIP WiFi and so can keep drive strengths low to > * reduce EMI. > -- > 1.8.1 > > -- > 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/ -- Shine bright, (: Nav :) -- 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/