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,URIBL_BLOCKED autolearn=ham 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 86BE0C43461 for ; Tue, 15 Sep 2020 22:11:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3A64A2080C for ; Tue, 15 Sep 2020 22:11:48 +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="YBlu85+T" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727861AbgIOWLn (ORCPT ); Tue, 15 Sep 2020 18:11:43 -0400 Received: from m43-7.mailgun.net ([69.72.43.7]:45779 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727711AbgIOQr2 (ORCPT ); Tue, 15 Sep 2020 12:47:28 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1600188446; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=yEHNYIgoLCIfyK1Nj7VW1RZeG1P4bPnr1BXOU5FeJZ8=; b=YBlu85+T1imHDCPyoDVk+Yl+W626qiEuBFbmvUkpi0FqTcj1CuwdO35j0uRDlIOvlj8Ye3Pj TWh4nR3MkqfQIM4B7QgiagCbiNpVO/jSI3kiA+3Su9z7DTR7RFi5Pka68v5CC59H95hDzTWb Wi+mHUyGWKEwKhKUyuS0fsac8rk= X-Mailgun-Sending-Ip: 69.72.43.7 X-Mailgun-Sid: WyI1MzIzYiIsICJsaW51eC1hcm0tbXNtQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n02.prod.us-east-1.postgun.com with SMTP id 5f60f01eba408b30ce29c230 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 15 Sep 2020 16:47:26 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 8A026C43385; Tue, 15 Sep 2020 16:47:25 +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: nguyenb) by smtp.codeaurora.org (Postfix) with ESMTPSA id 973EFC433F0; Tue, 15 Sep 2020 16:47:24 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Tue, 15 Sep 2020 09:47:24 -0700 From: nguyenb@codeaurora.org To: Bjorn Andersson Cc: cang@codeaurora.org, asutoshd@codeaurora.org, martin.petersen@oracle.com, linux-scsi@vger.kernel.org, linux-arm-msm@vger.kernel.org, Rob Herring , Avri Altman , Vinod Koul , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , open list Subject: Re: [PATCH v1 1/2] scsi: dt-bindings: ufs: Add vcc-voltage-level for UFS In-Reply-To: <20200915134335.GE670377@yoga> References: <0a9d395dc38433501f9652a9236856d0ac840b77.1598939393.git.nguyenb@codeaurora.org> <20200915044154.GB670377@yoga> <748d238a3d9e53834a498c6f37f9f3c9@codeaurora.org> <20200915134335.GE670377@yoga> Message-ID: X-Sender: nguyenb@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On 2020-09-15 06:43, Bjorn Andersson wrote: > On Tue 15 Sep 03:14 CDT 2020, nguyenb@codeaurora.org wrote: > >> On 2020-09-14 21:41, Bjorn Andersson wrote: >> > On Tue 01 Sep 01:00 CDT 2020, Bao D. Nguyen wrote: >> > >> > > UFS's specifications supports a range of Vcc operating >> > > voltage levels. Add documentation for the UFS's Vcc voltage >> > > levels setting. >> > > >> > > Signed-off-by: Can Guo >> > > Signed-off-by: Asutosh Das >> > > Signed-off-by: Bao D. Nguyen >> > > --- >> > > Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt | 2 ++ >> > > 1 file changed, 2 insertions(+) >> > > >> > > diff --git a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt >> > > b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt >> > > index 415ccdd..7257b32 100644 >> > > --- a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt >> > > +++ b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt >> > > @@ -23,6 +23,8 @@ Optional properties: >> > > with "phys" attribute, provides phandle >> > > to UFS PHY node >> > > - vdd-hba-supply : phandle to UFS host controller supply >> > > regulator node >> > > - vcc-supply : phandle to VCC supply regulator node >> > > +- vcc-voltage-level : specifies voltage levels for VCC supply. >> > > + Should be specified in pairs (min, max), >> > > units uV. >> > >> > What exactly are these pairs representing? >> The pair is the min and max Vcc voltage request to the PMIC chip. >> As a result, the regulator output voltage would only be in this range. >> > > If you have static min/max voltage constraints for a device on a > particular board the right way to handle this is to adjust the board's > regulator-min-microvolt and regulator-max-microvolt accordingly - and > not call regulator_set_voltage() from the river at all. > > In other words, you shouldn't add this new property to describe > something already described in the node vcc-supply points to. > > Regards, > Bjorn Thank you all for your comments. The current driver hardcoding 2.7V Vcc min voltage does not work for UFS3.0+ devices according to the UFS device JEDEC spec. However, we will try to address it in a different way. Regards, Bao > >> > >> > Is this supposed to be 3 pairs of (min,max) for vcc, vcc and vccq2 to be >> > passed into a regulator_set_voltage() for each regulator? >> Yes, that's right. I should include the other power supplies in this >> change >> as well. >> > >> > Or are these some sort of "operating points" for the vcc-supply? >> > >> > Regards, >> > Bjorn >> > >> > > - vccq-supply : phandle to VCCQ supply regulator node >> > > - vccq2-supply : phandle to VCCQ2 supply regulator node >> > > - vcc-supply-1p8 : For embedded UFS devices, valid VCC range >> > > is 1.7-1.95V >> > > -- >> > > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora >> > > Forum, >> > > a Linux Foundation Collaborative Project >> > >