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=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 DBE43C43603 for ; Wed, 4 Dec 2019 22:59:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A9B072073C for ; Wed, 4 Dec 2019 22:59:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="Q6GV4YFO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728427AbfLDW7g (ORCPT ); Wed, 4 Dec 2019 17:59:36 -0500 Received: from mail-lj1-f196.google.com ([209.85.208.196]:34988 "EHLO mail-lj1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728053AbfLDW7g (ORCPT ); Wed, 4 Dec 2019 17:59:36 -0500 Received: by mail-lj1-f196.google.com with SMTP id j6so1246302lja.2 for ; Wed, 04 Dec 2019 14:59:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=fWFWwBwf+/qh+51W0/5NvwSpZAa60WDVVrFmxyCiGJ4=; b=Q6GV4YFOrgQ5c+9IP5s9jGSWSfuhhOjW/yNKX4ZiHcEjqxqfxWUePFNfp2ITT6DEpk B5ke8aPhR/KfHVKaMWJ3LmN/B72Bxn9H5yk0XLZ2305rveH4Iwga33Zjp1acqyODPQFE JzvwcjC5Mtn1Xm91MqeB/FMsqUkIOeSO1qvO3zDm5uCpj2RSu3ZsCztbdu+fgGBVlyt+ OWuGmt96UdOAjif5Ii0UhfaSNgTW47N2tO++mnSsaPbLA1B1WfC69pEBRK2bPxqMtrsD fiSVCRsrExfRPCwMxfPK7ICBn9ynW7usSPHrcRAMLJB/nO07kOyB5wjy9L0rKmBRplqn uv7A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=fWFWwBwf+/qh+51W0/5NvwSpZAa60WDVVrFmxyCiGJ4=; b=ABCoYBfYce7RdHcbUngytfq1hjcS5xmg6mF/IzNT76QAXfh5rwjVd3PM0ns0/I2Nbp OWjheVzI9oVJnFHgb/IHnR72f933wH3HVafv4u3yi0XFigw+Q5C6Rbkz+X+RMSey6EIv gZdUVHQikomYCf/21JTS2TFy/RHIenSpTu/ZHKE1b/UlEhki/8NBqEPAHHULLBwdFAEH yf4B9jYAWCZNADMnARovGZiJhP+pqjZYnrlGt3LB4+A2cgomd5bYjV6ArstB0nQ9NQhH RaLAcb0/WXYe9h9TmSx50DSSGXNrEO65ECbCG80/429Nuj7P0B90Cl/JW+/VB8D3djfh iwYQ== X-Gm-Message-State: APjAAAVBx9br4rTuX0J6Uk2uqzAbCSNyNjY2qCMalSRfgZ6NreEgiymo GmWO5Doo/4lQdX6iqOf7R2l6mA== X-Google-Smtp-Source: APXvYqxEqBG4MusBCBt0f+STRiBuyZvdoWR1urmtC87SC8C18KEH2/CYvMW3eTWDuk4ahL98GCrRsA== X-Received: by 2002:a05:651c:2011:: with SMTP id s17mr3374796ljo.43.1575500374246; Wed, 04 Dec 2019 14:59:34 -0800 (PST) Received: from localhost.localdomain (c-21cd225c.014-348-6c756e10.bbcust.telenor.se. [92.34.205.33]) by smtp.gmail.com with ESMTPSA id y8sm3964358lji.56.2019.12.04.14.59.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Dec 2019 14:59:33 -0800 (PST) From: Linus Walleij To: Alessandro Zummo , Alexandre Belloni Cc: linux-rtc@vger.kernel.org, Linus Walleij , Mark Brown Subject: [PATCH] rtc: ds1343: Do not hardcode SPI mode flags Date: Wed, 4 Dec 2019 23:57:31 +0100 Message-Id: <20191204225731.20306-1-linus.walleij@linaro.org> X-Mailer: git-send-email 2.23.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-rtc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rtc@vger.kernel.org The current use of mode flags to us SPI_MODE_3 and SPI_CS_HIGH is fragile: it overwrites anything already assigned by the SPI core. Change it thusly: - Just |= the SPI_MODE_3 so we keep other flags - Assign ^= SPI_CS_HIGH since we might be active high already, and that is usually the case with GPIOs used for chip select, even if they are in practice active low. Add a comment clarifying why ^= SPI_CS_HIGH is the right choice here. Reported-by: Mark Brown Signed-off-by: Linus Walleij --- drivers/rtc/rtc-ds1343.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/rtc/rtc-ds1343.c b/drivers/rtc/rtc-ds1343.c index fa6de31d5793..105a2fd93583 100644 --- a/drivers/rtc/rtc-ds1343.c +++ b/drivers/rtc/rtc-ds1343.c @@ -484,9 +484,12 @@ static int ds1343_probe(struct spi_device *spi) mutex_init(&priv->mutex); /* RTC DS1347 works in spi mode 3 and - * its chip select is active high + * its chip select is active high. Active high should be defined as + * "inverse polarity" as GPIO-based chip selects can be logically + * active high but inverted by the GPIO library. */ - spi->mode = SPI_MODE_3 | SPI_CS_HIGH; + spi->mode |= SPI_MODE_3; + spi->mode ^= SPI_CS_HIGH; spi->bits_per_word = 8; res = spi_setup(spi); if (res) -- 2.23.0