From patchwork Mon Jun 20 15:47:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Olivier Moysan X-Patchwork-Id: 12887871 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 819D2C43334 for ; Mon, 20 Jun 2022 15:49:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=peF7+Y4p/6y8WchCOTdhzk2bX9b9PfNNHl5gslzWuDg=; b=kKUVz7ZMQqiRmh bS/z5cuqa6Sg8P6SZWxAnUL9q/+ucDnbhbXTgIi4I+HIYrF+EqtzI3mLWRb4JCWUDXidqwF7lu7tj G+ZXUWrSI5PZV49yHN/YqWZ7CVdgA1dC+atJjBbMAQ1J8tXON5jM+EWV92YOhJU7atBxeBmwfX3R4 WuBguQuTbdKKlt1h4j2ZgbqLICzSkB83MqjkySVu4hwrLUo3J3fc37ZmKZTZGcJEam7Z2jhsyFnsJ KpuCawOIMOWWxGRUfbgEMETnLaybrrlf0v1nhkZzNYgPkXz0aDVDLgjdjnQ6g2XLR/0YZwhHNNKpn UzFNPcTQHzBHL9J9YGfw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o3Jdo-001JLl-1f; Mon, 20 Jun 2022 15:48:40 +0000 Received: from mx07-00178001.pphosted.com ([185.132.182.106]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1o3Jda-001JDM-41 for linux-arm-kernel@lists.infradead.org; Mon, 20 Jun 2022 15:48:27 +0000 Received: from pps.filterd (m0288072.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 25KEiC4u002735; Mon, 20 Jun 2022 17:48:14 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=selector1; bh=zPr/nDv+NqgCll4/QE6301YdTarimLKEYjm6hZt54cU=; b=3QrMbbUQhJfejLee/ZUMrRps4gsh9KU/5BNqES9+Y1FM8bHXgXX3LfDRplf3l4mjVHon 1DNovKqTAHNFtTJ6gMbtb/ncA5PoiDf4gIWlecpfU63y/qjmQeXt3eXHxNTfSxKG0QsV A4e94mhm5/JFdYG6AuPhPUj1A8acMdkMpMC7b/aqhU8lmDwfqPTuLoenH+3eNR/g+kNI w9qpwgTzjBZSu6IU6L2oJKxuFX0szRfGgrlDFuJgAioXHhGbLh11juTXP+Vj+DCz9JlK u4o6kXi3xeZGTVs3WnqSI4+J+X9VKwGcJApVv1rZ6L2vhD05NrLhdsZZmp+Yc4RdZ8n+ ng== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com (PPS) with ESMTPS id 3gs71tmchc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 20 Jun 2022 17:48:14 +0200 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 96F42100038; Mon, 20 Jun 2022 17:48:13 +0200 (CEST) Received: from Webmail-eu.st.com (shfdag1node1.st.com [10.75.129.69]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 90F7722ECEF; Mon, 20 Jun 2022 17:48:13 +0200 (CEST) Received: from localhost (10.75.127.119) by SHFDAG1NODE1.st.com (10.75.129.69) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2308.20; Mon, 20 Jun 2022 17:48:13 +0200 From: Olivier Moysan To: Alexandre Torgue , Fabrice Gasnier , Jonathan Cameron , Lars-Peter Clausen , Maxime Coquelin , Olivier Moysan , Paul Cercueil , Wan Jiabing CC: , , , Subject: [PATCH 2/2] iio: adc: stm32-adc: disable adc before calibration Date: Mon, 20 Jun 2022 17:47:38 +0200 Message-ID: <20220620154738.801706-3-olivier.moysan@foss.st.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220620154738.801706-1-olivier.moysan@foss.st.com> References: <20220620154738.801706-1-olivier.moysan@foss.st.com> MIME-Version: 1.0 X-Originating-IP: [10.75.127.119] X-ClientProxiedBy: GPXDAG2NODE5.st.com (10.75.127.69) To SHFDAG1NODE1.st.com (10.75.129.69) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.883,Hydra:6.0.517,FMLib:17.11.64.514 definitions=2022-06-20_05,2022-06-17_01,2022-02-23_01 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220620_084826_502337_7D71C216 X-CRM114-Status: GOOD ( 15.46 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The calibration is launched from prepare callback. The ADC state when entering this function may be unknown as the ADC may have been left enabled by boot stage. One prerequisite for ADC calibration is to have ADC in disabled state. If the calibration is started when ADC is still enabled, the behavior is unpredictable, and the calibration may fail with a timeout error. Force ADC to disabled state in stm32h7_adc_selfcalib(). ADC enabling is ensured by stm32h7_adc_enable() call, before leaving prepare callback. Signed-off-by: Olivier Moysan Reviewed-by: Fabrice Gasnier --- drivers/iio/adc/stm32-adc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c index 80e333f65ddd..3985fe972892 100644 --- a/drivers/iio/adc/stm32-adc.c +++ b/drivers/iio/adc/stm32-adc.c @@ -1019,6 +1019,9 @@ static int stm32h7_adc_selfcalib(struct iio_dev *indio_dev) if (adc->cal.calibrated) return true; + /* ADC must be disabled for calibration */ + stm32h7_adc_disable(indio_dev); + /* * Select calibration mode: * - Offset calibration for single ended inputs