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 X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C9404C433DF for ; Wed, 19 Aug 2020 13:50:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A1F7E2075E for ; Wed, 19 Aug 2020 13:50:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="EWwJdb63" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728639AbgHSNu1 (ORCPT ); Wed, 19 Aug 2020 09:50:27 -0400 Received: from m43-7.mailgun.net ([69.72.43.7]:45266 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728624AbgHSNte (ORCPT ); Wed, 19 Aug 2020 09:49:34 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1597844973; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=0mtotj0y7f/ujlPF/3BquuIrAPK++4mXpR4ueE77w5Y=; b=EWwJdb63BXCa66o/fuatQ3Vf5U28Lga1lSaHzp4fksPhNSpVmPpCCDADoYaQ3tnd0+/8WRak lCES+8vdpMNj9ZFHcuCAAswMNjrxB4jP4qc1jPikpGbY8ORcJynu5JWA4x+Vql5a4MIqhERH 7nKCVfMqZ90yo7AYY3wiVdFD5jY= X-Mailgun-Sending-Ip: 69.72.43.7 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n03.prod.us-east-1.postgun.com with SMTP id 5f3d2de6d90407f0b972b868 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Wed, 19 Aug 2020 13:49:26 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id B1D36C433CB; Wed, 19 Aug 2020 13:49:25 +0000 (UTC) Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: skakit) by smtp.codeaurora.org (Postfix) with ESMTPSA id 15974C433C6; Wed, 19 Aug 2020 13:49:25 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 19 Aug 2020 19:19:25 +0530 From: skakit@codeaurora.org To: Matthias Kaehlcke Cc: Bjorn Andersson , gregkh@linuxfoundation.org, Andy Gross , Rob Herring , linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, akashast@codeaurora.org, rojay@codeaurora.org, msavaliy@qti.qualcomm.com Subject: Re: [PATCH V2 2/3] arm64: dts: qcom: sc7180: Add sleep pin ctrl for BT uart In-Reply-To: <20200817180158.GD2995789@google.com> References: <1595563082-2353-1-git-send-email-skakit@codeaurora.org> <1595563082-2353-3-git-send-email-skakit@codeaurora.org> <20200817180158.GD2995789@google.com> Message-ID: <1cbbc8cf5c918c6a9eee5ef349707fc6@codeaurora.org> X-Sender: skakit@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-08-17 23:31, Matthias Kaehlcke wrote: > On Fri, Jul 24, 2020 at 09:28:01AM +0530, satya priya wrote: >> Add sleep pin ctrl for BT uart, and also change the bias >> configuration to match Bluetooth module. >> >> Signed-off-by: satya priya >> --- >> Changes in V2: >> - This patch adds sleep state for BT UART. Newly added in V2. >> >> arch/arm64/boot/dts/qcom/sc7180-idp.dts | 42 >> ++++++++++++++++++++++++++++----- >> 1 file changed, 36 insertions(+), 6 deletions(-) >> >> diff --git a/arch/arm64/boot/dts/qcom/sc7180-idp.dts >> b/arch/arm64/boot/dts/qcom/sc7180-idp.dts >> index 26cc491..bc919f2 100644 >> --- a/arch/arm64/boot/dts/qcom/sc7180-idp.dts >> +++ b/arch/arm64/boot/dts/qcom/sc7180-idp.dts >> @@ -469,20 +469,50 @@ >> >> &qup_uart3_default { >> pinconf-cts { >> - /* >> - * Configure a pull-down on 38 (CTS) to match the pull of >> - * the Bluetooth module. >> - */ >> + /* Configure no pull on 38 (CTS) to match Bluetooth module */ > > Has the pull from the Bluetooth module been removed or did the previous > config > incorrectly claim that the Bluetooth module has a pull-down? > The previous config was incorrect, so we corrected it to match the pull of BT. >> pins = "gpio38"; >> + bias-disable; >> + }; >> + >> + pinconf-rts { >> + /* We'll drive 39 (RTS), so configure pull-down */ >> + pins = "gpio39"; >> + drive-strength = <2>; >> bias-pull-down; >> + }; >> + >> + pinconf-tx { >> + /* We'll drive 40 (TX), so no pull */ > > The rationales for RTS and TX contradict each other. According to the > comment > the reason to configure a pull-down on RTS is that it is driven by the > host. > Then for TX the reason to configure no pull is that it is driven by the > host. > > Please make sure the comments *really* describe the rationale, > otherwise they > are just confusing. The rationale for RTS is that we don't want it to be floating and want to make sure that it is pulled down, to receive bytes. Will modify the comment mentioning the same.