From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kukjin Kim Subject: Re: [PATCH 1/4] ARM: dts: exynos5250-snow: add pinctrl for i2c-arbitrator Date: Fri, 16 May 2014 04:54:20 +0900 Message-ID: <53751B6C.9020106@samsung.com> References: <1397481367-12652-1-git-send-email-sachin.kamat@linaro.org> <534C6380.3040806@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-pb0-f41.google.com ([209.85.160.41]:43963 "EHLO mail-pb0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751582AbaEOTyb (ORCPT ); Thu, 15 May 2014 15:54:31 -0400 In-Reply-To: Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Doug Anderson Cc: Tomasz Figa , Sachin Kamat , Olof Johansson , linux-samsung-soc , Kukjin Kim , sunil joshi , AJAY KUMAR RAMAKRISHNA SHYMALAMMA , Simon Glass , "devicetree@vger.kernel.org" On 04/15/14 07:53, Doug Anderson wrote: + DT ML > Tomasz, > > On Mon, Apr 14, 2014 at 3:38 PM, Tomasz Figa wrote: >> Hi Doug, >> >> >> On 15.04.2014 00:30, Doug Anderson wrote: >>> >>> Sachin, >>> >>> On Mon, Apr 14, 2014 at 6:16 AM, Sachin Kamat >>> wrote: >>>> >>>> From: Doug Anderson >>> >>> >>> I probably wouldn't have bothered giving me authorship since this >>> isn't exactly a clean patch from the chromium tree (you pulled the >>> proper pieces yourself, did the commit message yourself, etc). ...but >>> I appreciate the thought and as far as I know setting the "author" in >>> cases like this is a bit of a judgement call... >>> >>> The Signed-off-by is certainly correct. ;) >>> >>>> >>>> Added i2c-arbitrator pinctrl node to Snow board. >>>> >>>> Signed-off-by: Doug Anderson >>>> Signed-off-by: Sachin Kamat >>>> --- >>>> arch/arm/boot/dts/exynos5250-snow.dts | 19 +++++++++++++++++++ >>>> 1 file changed, 19 insertions(+) >>> >>> >>> This matches what's in our tree and and is what people are using, so: >>> >>> Reviewed-by: Doug Anderson >>> >>> >>>> diff --git a/arch/arm/boot/dts/exynos5250-snow.dts >>>> b/arch/arm/boot/dts/exynos5250-snow.dts >>>> index 1ce1088..32715b3 100644 >>>> --- a/arch/arm/boot/dts/exynos5250-snow.dts >>>> +++ b/arch/arm/boot/dts/exynos5250-snow.dts >>>> @@ -39,6 +39,22 @@ >>>> }; >>>> }; >>>> >>>> + pinctrl@13400000 { >>>> + arb_their_claim: arb-their-claim { >>>> + samsung,pins = "gpe0-4"; >>>> + samsung,pin-function =<0>; >>>> + samsung,pin-pud =<3>; >>>> + samsung,pin-drv =<0>; >>>> + }; >>>> + >>>> + arb_our_claim: arb-our-claim { >>>> + samsung,pins = "gpf0-3"; >>>> + samsung,pin-function =<1>; >>>> + samsung,pin-pud =<0>; >>>> + samsung,pin-drv =<0>; >>>> + }; >>> >>> >>> It's odd to me that one of these has a pullup but not the other, but I >>> think that's because the arbitration lines ended up using some other >>> signals that were originally hooked up for other usage. Certainly the >>> pullups / pulldowns match what's in our tree and also match what we >>> had in the original shipping 3.4 kernel. >> >> >> Just a wild guess, but probably the input needs a pull-up, while obviously >> the output doesn't. I don't have much idea about the arbitration thing >> happening on snow, so I can't say much about this series. (Maybe description >> of patch 1/4 should be saying a bit more about the meaning of this?) > > Right, of course. I'm not sure quite what I was thinking. I think I > was getting confused since these go through level converters and my > brain was in open drain mode. ...but looking at this again this looks > reasonable. > > I think the whole discussion of arbitration was from a long time ago. > I think it's fairly well documented in the "i2c-arb-gpio-challenge" > driver. > > Basically it looks like Sachin is getting pinctrl stuff matched up > properly for the device tree that's upstream. > Sounds OK to me. Tomasz, do you have any concerns still? Thanks, Kukjin