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=-0.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 E61B1C6778F for ; Thu, 26 Jul 2018 13:06:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7F86F20844 for ; Thu, 26 Jul 2018 13:06:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=agner.ch header.i=@agner.ch header.b="ppU/kB0X" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7F86F20844 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=agner.ch Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730285AbeGZOWq (ORCPT ); Thu, 26 Jul 2018 10:22:46 -0400 Received: from mail.kmu-office.ch ([178.209.48.109]:56162 "EHLO mail.kmu-office.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729506AbeGZOWq (ORCPT ); Thu, 26 Jul 2018 10:22:46 -0400 Received: from webmail.kmu-office.ch (unknown [IPv6:2a02:418:6a02::a3]) by mail.kmu-office.ch (Postfix) with ESMTPSA id DEE995C19DE; Thu, 26 Jul 2018 15:05:55 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=agner.ch; s=dkim; t=1532610355; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=w0G+GpxMk0BT6hCUHaC/Lmmw8jaXlg8cl+mqEXI/m9c=; b=ppU/kB0XM/NmZD0meHsJj3OW/qzaNJ1U3klSJ2zV5r1BtEh8sNq34wSsf3swCAWVI6k1Lg cIZ2hxPm3Z1sf1S2BM/QjIgS5Za0BHOmDv5keCFh+Hw24UtXJrvBIcSiv/134TCGajQhtN qCHSy2n3tV3vQkFYeJn2Jee2MUbzZ88= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Date: Thu, 26 Jul 2018 15:05:55 +0200 From: Stefan Agner To: Aapo Vienamo Cc: Ulf Hansson , Rob Herring , Mark Rutland , Thierry Reding , Jonathan Hunter , Adrian Hunter , Mikko Perttunen , linux-mmc@vger.kernel.org, devicetree@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, linux-tegra-owner@vger.kernel.org Subject: Re: [PATCH v2 02/10] dt-bindings: mmc: tegra: Add nvidia,only-1-8-v property In-Reply-To: <1532607560-11253-3-git-send-email-avienamo@nvidia.com> References: <1532607560-11253-1-git-send-email-avienamo@nvidia.com> <1532607560-11253-3-git-send-email-avienamo@nvidia.com> Message-ID: <484a31bdaad6d76b4fbb7d6fa80cbb8d@agner.ch> X-Sender: stefan@agner.ch User-Agent: Roundcube Webmail/1.3.4 X-Spamd-Result: default: False [-2.99 / 15.00]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; RCPT_COUNT_TWELVE(0.00)[13]; TAGGED_RCPT(0.00)[dt]; MIME_GOOD(-0.10)[text/plain]; FROM_HAS_DN(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; DKIM_SIGNED(0.00)[]; TO_DN_SOME(0.00)[]; RCVD_COUNT_ZERO(0.00)[0]; RCVD_TLS_ALL(0.00)[]; BAYES_HAM(-2.89)[99.54%]; ARC_NA(0.00)[] Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 26.07.2018 14:19, Aapo Vienamo wrote: > Add a property to mark controllers which operate at a 1.8 V fixed I/O > voltage. > > This feature of the hardware needs to be signaled this way because it > cannot be probed at runtime or reliably derived from other properties. Is this really needed? Can we not use vqmmc to determine which voltage the controller runs on? There is already some precedence in the SDHCI core to determine which voltage levels are supported: https://lkml.org/lkml/2018/7/5/342 -- Stefan > > Signed-off-by: Aapo Vienamo > --- > Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git > a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt > b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt > index 90c214d..95010cf 100644 > --- a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt > +++ b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt > @@ -45,6 +45,8 @@ Optional properties for Tegra210 and Tegra186: > for controllers supporting multiple voltage levels. The order of names > should correspond to the pin configuration states in pinctrl-0 and > pinctrl-1. > +- nvidia,only-1-8-v : The presence of this property indicates that the > + controller operates at a 1.8 V fixed I/O voltage. > > Example: > sdhci@700b0000 {