From patchwork Wed Sep 15 15:51:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miquel Raynal X-Patchwork-Id: 12496443 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,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 9038FC433EF for ; Wed, 15 Sep 2021 15:52:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 777C1606A5 for ; Wed, 15 Sep 2021 15:52:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238487AbhIOPxV (ORCPT ); Wed, 15 Sep 2021 11:53:21 -0400 Received: from relay12.mail.gandi.net ([217.70.178.232]:34305 "EHLO relay12.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238274AbhIOPxF (ORCPT ); Wed, 15 Sep 2021 11:53:05 -0400 Received: (Authenticated sender: miquel.raynal@bootlin.com) by relay12.mail.gandi.net (Postfix) with ESMTPSA id 0C77720001D; Wed, 15 Sep 2021 15:51:26 +0000 (UTC) From: Miquel Raynal To: Jonathan Cameron , Lars-Peter Clausen , linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Thomas Petazzoni , Nuno Sa , Miquel Raynal Subject: [PATCH v3 12/14] iio: adc: max1027: Introduce an end of conversion helper Date: Wed, 15 Sep 2021 17:51:15 +0200 Message-Id: <20210915155117.475962-13-miquel.raynal@bootlin.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20210915155117.475962-1-miquel.raynal@bootlin.com> References: <20210915155117.475962-1-miquel.raynal@bootlin.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org For now this helper only waits for the maximum duration of a single conversion (even though a temperature measurement will take twice this time, we only care about the temperature which happens first, so we will still only wait for a single sample). This helper will soon be improved to properly handle the end of conversion interrupt as well as a higher number of samples. Signed-off-by: Miquel Raynal --- drivers/iio/adc/max1027.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c index a044f4b598e0..e0175448c899 100644 --- a/drivers/iio/adc/max1027.c +++ b/drivers/iio/adc/max1027.c @@ -60,6 +60,9 @@ #define MAX1027_NAVG_32 (0x03 << 2) #define MAX1027_AVG_EN BIT(4) +/* Device can achieve 300ksps so we assume a 3.33us conversion delay */ +#define MAX1027_CONVERSION_UDELAY 4 + enum max1027_id { max1027, max1029, @@ -271,6 +274,15 @@ struct max1027_state { u8 reg ____cacheline_aligned; }; +static int max1027_wait_eoc(struct iio_dev *indio_dev) +{ + unsigned int conversion_time = MAX1027_CONVERSION_UDELAY; + + usleep_range(conversion_time, conversion_time * 2); + + return 0; +} + /* Scan from chan 0 to the highest requested channel. Include temperature on demand. */ static int max1027_configure_chans_and_start(struct iio_dev *indio_dev) { @@ -330,9 +342,11 @@ static int max1027_read_single_value(struct iio_dev *indio_dev, /* * For an unknown reason, when we use the mode "10" (write * conversion register), the interrupt doesn't occur every time. - * So we just wait 1 ms. + * So we just wait the maximum conversion time and deliver the value. */ - mdelay(1); + ret = max1027_wait_eoc(indio_dev); + if (ret) + return ret; /* Read result */ ret = spi_read(st->spi, st->buffer, (chan->type == IIO_TEMP) ? 4 : 2);