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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,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 4A8E4C43381 for ; Sun, 24 Mar 2019 17:51:45 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1DE2C218AC for ; Sun, 24 Mar 2019 17:51:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="IbjUhdXl" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1DE2C218AC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=martin.sperl.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=7lPTBsfKly7zLtYSppOWWY/vaJ/ozNWT4XBCWG7rQGs=; b=IbjUhdXlizd37RKj9lffEvW63p RFRr07fjEL0i/255K9TwHgTwtNwTgYohcSY3dK8snRZ/U4eLfTwh0h0eCDSRezU6gEdWc0K//g9IC 11LCp4tICTre/LIcf1aPK7zvWHaBSG4yWHFeumDgk9ucdhFu1dZfI1oygHmH/cZkvMSwPNRhUPksD +SyhbnlHuqF4d4zZtamlobEE62LIJTlYKzJMoGAjqhb8DSdEby6Ol1KJXMfY5Gj9FXse3k/9w8hl+ CgJOSM3DISNQnPu0osTryqcBSTYy5UPt2K6ri+uQe3j4KFpHRt83jrBPrTWhdQO/z/7nnhZ9oksdY O8iulJYA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1h87HY-0000h6-KQ; Sun, 24 Mar 2019 17:51:40 +0000 Received: from 212-186-180-163.static.upcbusiness.at ([212.186.180.163] helo=cgate.sperl.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1h87Ga-0007UD-Ui; Sun, 24 Mar 2019 17:50:47 +0000 Received: from hc1.intern.sperl.org (account martin@sperl.org [10.10.10.59] verified) by sperl.org (CommuniGate Pro SMTP 6.2.1 _community_) with ESMTPSA id 7759428; Sun, 24 Mar 2019 17:50:11 +0000 From: kernel@martin.sperl.org To: Mark Brown , Eric Anholt , Stefan Wahren , Hubert Denkmair , linux-spi@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH V2 6/9] spi: bcm2835aux: warn in dmesg that native cs is not really supported Date: Sun, 24 Mar 2019 17:49:59 +0000 Message-Id: <20190324175002.28969-7-kernel@martin.sperl.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20190324175002.28969-1-kernel@martin.sperl.org> References: <20190324175002.28969-1-kernel@martin.sperl.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190324_105041_477160_11BD9C76 X-CRM114-Status: GOOD ( 12.26 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Martin Sperl MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Martin Sperl >From personal bad experience (even as the author of the original driver) it shows that native-cs is "somewhat" supported by the spi bus driver when using a buggy device tree. So make sure that the driver is warning in dmesg about this fact that we are running in a not supported mode that may have surprizing limitations. Signed-off-by: Martin Sperl Fixes: 1ea29b39f4c812ece2f936065a0a3d6fe44a263e --- drivers/spi/spi-bcm2835aux.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/drivers/spi/spi-bcm2835aux.c b/drivers/spi/spi-bcm2835aux.c index c8acde017b6a..6af07dec5fdc 100644 --- a/drivers/spi/spi-bcm2835aux.c +++ b/drivers/spi/spi-bcm2835aux.c @@ -396,6 +396,38 @@ static void bcm2835aux_spi_handle_err(struct spi_master *master, bcm2835aux_spi_reset_hw(bs); } +static int bcm2835aux_spi_setup(struct spi_device *spi) +{ + int ret; + + if (spi->mode & SPI_NO_CS) + return 0; + /* sanity check for native cs */ + if (!gpio_is_valid(spi->cs_gpio)) { + /* for dt-backwards compatibility: only support native on CS0 + * known things not supported with broken native CS: + * * multiple chip-selects: cs0-cs2 are all + * simultaniously asserted whenever there is a transfer + * this even includes SPI_NO_CS + * * SPI_CS_HIGH: cs are always asserted low + * * cs_change: cs is deasserted after each spi_transfer + * * cs_delay_usec: cs is always deasserted one SCK cycle + * after the last transfer + * probably more... + */ + if (spi->chip_select == 0) { + dev_err(&spi->dev, + "native CS is not supported but may work for some use-cases for cs = 0 - please define a valid value cs-gpios in DT for complete feature set\n"); + return 0; + } + dev_err(&spi->dev, + "native CS is not supported for cs > 0 - please define a valid value cs-gpios in DT to enable multiple cs\n"); + return -EINVAL; + } + + return 0; +} + static int bcm2835aux_spi_probe(struct platform_device *pdev) { struct spi_master *master; @@ -425,6 +457,7 @@ static int bcm2835aux_spi_probe(struct platform_device *pdev) * a spi_transfer */ master->num_chipselect = 1; + master->setup = bcm2835aux_spi_setup; master->transfer_one = bcm2835aux_spi_transfer_one; master->handle_err = bcm2835aux_spi_handle_err; master->prepare_message = bcm2835aux_spi_prepare_message; -- 2.11.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel