From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7B7CFC4332F for ; Thu, 15 Dec 2022 20:49:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229867AbiLOUta (ORCPT ); Thu, 15 Dec 2022 15:49:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43096 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229864AbiLOUt2 (ORCPT ); Thu, 15 Dec 2022 15:49:28 -0500 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8023026AA3; Thu, 15 Dec 2022 12:49:27 -0800 (PST) Received: from pps.filterd (m0279873.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 2BFKQwGT009458; Thu, 15 Dec 2022 20:49:22 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=qcppdkim1; bh=VK6BeCywnJYOa+0P4ryIqF9jCO11IlECxLhsDeBfXyM=; b=YEkJ/3lvY2W/6Qqqo5M9NZXMP+FKDvx8ytoD1xiltCtpJqgfKujYqEkCQNolUiRZNAs0 w+KQtfOqcDw5JCmc0QhkyxMlQBjkJuXwftlpKfvXptS8Pt08KLMrUMv9Vk75bk4hpzTZ yy0XnlvQOF0pafOfMzYf9Dvn6n4BGe3BFwZ3MNAphRzV+XxC/cCOt/8ktpPoZLq+Qw43 fKl5R/WKX0C8NJmcbkN1RyXFFt8usaviClIYYu25kgg1TtkpTdqHX7iz1XErdVOcj5Nk kmIhbv36cpXQ5MfSRP01ZuaSbpr4Tu7zCdQTaAwwIZ9rOZ2w2yFbLTkqToXuKglwFwaP iw== Received: from nalasppmta04.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3mfxseaj43-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 15 Dec 2022 20:49:21 +0000 Received: from nalasex01c.na.qualcomm.com (nalasex01c.na.qualcomm.com [10.47.97.35]) by NALASPPMTA04.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 2BFKnKnF007071 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 15 Dec 2022 20:49:20 GMT Received: from core-thresher1.qualcomm.com (10.80.80.8) by nalasex01c.na.qualcomm.com (10.47.97.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.36; Thu, 15 Dec 2022 12:49:20 -0800 Date: Thu, 15 Dec 2022 12:49:18 -0800 From: Bjorn Andersson To: Neil Armstrong CC: Linus Walleij , Abel Vesa , Andy Gross , Bjorn Andersson , Konrad Dybcio , Rob Herring , Krzysztof Kozlowski , Linux Kernel Mailing List , , , "linux-gpio@vger.kernel.org" Subject: Re: [PATCH v2 2/4] dt-bindings: pinctrl: qcom,tlmm-common: document i2c pull property Message-ID: <20221215204615.GA19388@core-thresher1.qualcomm.com> References: <20221123152001.694546-1-abel.vesa@linaro.org> <20221123152001.694546-3-abel.vesa@linaro.org> <8602cacd-f552-e843-5c17-681b099069a3@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nalasex01c.na.qualcomm.com (10.47.97.35) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-ORIG-GUID: nwRNLs4KNGuiwhYtkj-TaKeQrt4ea046 X-Proofpoint-GUID: nwRNLs4KNGuiwhYtkj-TaKeQrt4ea046 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.923,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-12-15_11,2022-12-15_02,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 adultscore=0 clxscore=1011 spamscore=0 phishscore=0 priorityscore=1501 malwarescore=0 suspectscore=0 mlxscore=0 bulkscore=0 lowpriorityscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2212150174 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Tue, Nov 29, 2022 at 09:15:02AM +0100, Neil Armstrong wrote: > Hi Linus, > > On 26/11/2022 22:53, Linus Walleij wrote: > > On Fri, Nov 25, 2022 at 1:40 PM wrote: > > > > > As I understood, it enables an "I2C resistor" on the pin, removing the need > > > of an external pull-up resistor on the line. > > > > > > I assume the classical pull-up bias is not strong enough to replace an actual > > > resistor on the PCB. That is correct. > > > > In that case I think this should be an argument to bias-pull-up like: > > > > bias-pull-up = <360000>; > > > > Nominally the pull up is in ohms: > > > > bias-pull-up: > > oneOf: > > - type: boolean > > - $ref: /schemas/types.yaml#/definitions/uint32 > > description: pull up the pin. Takes as optional argument on hardware > > supporting it the pull strength in Ohm. > > > > Then the driver can choose to shunt in this extra I2C resistance > > from the resistance passed as argument. So no special property > > is needed, provided you can get an idea about the resistance > > provided here. > > I like this alternative, I'll try to figure out if we can find a value > to match against. > The typical value for this resistor is 2.2kOhm. Regards, Bjorn