From patchwork Wed Apr 15 21:22:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Alexandre Belloni X-Patchwork-Id: 11492053 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 92DBC6CA for ; Wed, 15 Apr 2020 21:23:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7A99020784 for ; Wed, 15 Apr 2020 21:23:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2438919AbgDOVXO (ORCPT ); Wed, 15 Apr 2020 17:23:14 -0400 Received: from relay12.mail.gandi.net ([217.70.178.232]:37605 "EHLO relay12.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2438899AbgDOVXL (ORCPT ); Wed, 15 Apr 2020 17:23:11 -0400 Received: from localhost (lfbn-lyo-1-9-35.w86-202.abo.wanadoo.fr [86.202.105.35]) (Authenticated sender: alexandre.belloni@bootlin.com) by relay12.mail.gandi.net (Postfix) with ESMTPSA id 05AFA200003; Wed, 15 Apr 2020 21:23:05 +0000 (UTC) From: Alexandre Belloni To: Jonathan Cameron Cc: Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , Gregory CLEMENT , linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, Alexandre Belloni Subject: [PATCH 1/3] iio: adc: ti-ads8344: properly byte swap value Date: Wed, 15 Apr 2020 23:22:55 +0200 Message-Id: <20200415212257.161238-2-alexandre.belloni@bootlin.com> X-Mailer: git-send-email 2.25.2 In-Reply-To: <20200415212257.161238-1-alexandre.belloni@bootlin.com> References: <20200415212257.161238-1-alexandre.belloni@bootlin.com> MIME-Version: 1.0 Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org The first received byte is the MSB, followed by the LSB so the value needs to be byte swapped. Also, the ADC actually has a delay of one clock on the SPI bus. Read three bytes to get the last bit. Fixes: 8dd2d7c0fed7 ("iio: adc: Add driver for the TI ADS8344 A/DC chips") Signed-off-by: Alexandre Belloni Reported-by: kbuild test robot --- drivers/iio/adc/ti-ads8344.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/iio/adc/ti-ads8344.c b/drivers/iio/adc/ti-ads8344.c index 9a460807d46d..6da50ea35217 100644 --- a/drivers/iio/adc/ti-ads8344.c +++ b/drivers/iio/adc/ti-ads8344.c @@ -29,7 +29,6 @@ struct ads8344 { struct mutex lock; u8 tx_buf ____cacheline_aligned; - u16 rx_buf; }; #define ADS8344_VOLTAGE_CHANNEL(chan, si) \ @@ -76,6 +75,7 @@ static int ads8344_adc_conversion(struct ads8344 *adc, int channel, { struct spi_device *spi = adc->spi; int ret; + u8 buf[3]; adc->tx_buf = ADS8344_START; if (!differential) @@ -89,11 +89,11 @@ static int ads8344_adc_conversion(struct ads8344 *adc, int channel, udelay(9); - ret = spi_read(spi, &adc->rx_buf, 2); + ret = spi_read(spi, buf, sizeof(buf)); if (ret) return ret; - return adc->rx_buf; + return buf[0] << 9 | buf[1] << 1 | buf[2] >> 7; } static int ads8344_read_raw(struct iio_dev *iio,