From patchwork Wed Apr 15 21:22:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Belloni X-Patchwork-Id: 11492055 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 63DDF6CA for ; Wed, 15 Apr 2020 21:23:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4BF7620784 for ; Wed, 15 Apr 2020 21:23:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2438958AbgDOVXQ (ORCPT ); Wed, 15 Apr 2020 17:23:16 -0400 Received: from relay12.mail.gandi.net ([217.70.178.232]:59015 "EHLO relay12.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2438917AbgDOVXL (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 C7B2C200004; Wed, 15 Apr 2020 21:23:07 +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 3/3] iio: adc: ti-ads8344: optimize consumption Date: Wed, 15 Apr 2020 23:22:57 +0200 Message-Id: <20200415212257.161238-4-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 Set the clock mode only once, at probe time and then keep the ADC powered down between conversions. Signed-off-by: Alexandre Belloni --- drivers/iio/adc/ti-ads8344.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/iio/adc/ti-ads8344.c b/drivers/iio/adc/ti-ads8344.c index 9b2d3a8ea6bd..0804650d8d8a 100644 --- a/drivers/iio/adc/ti-ads8344.c +++ b/drivers/iio/adc/ti-ads8344.c @@ -65,7 +65,7 @@ static const struct iio_chan_spec ads8344_channels[] = { }; static int ads8344_adc_conversion(struct ads8344 *adc, int channel, - bool differential) + bool differential, u8 clock) { struct spi_device *spi = adc->spi; int ret; @@ -75,7 +75,7 @@ static int ads8344_adc_conversion(struct ads8344 *adc, int channel, if (!differential) buf[0] |= ADS8344_SINGLE_END; buf[0] |= ADS8344_CHANNEL(channel); - buf[0] |= ADS8344_CLOCK_INTERNAL; + buf[0] |= clock; ret = spi_write(spi, buf, 1); if (ret) @@ -100,7 +100,7 @@ static int ads8344_read_raw(struct iio_dev *iio, case IIO_CHAN_INFO_RAW: mutex_lock(&adc->lock); *value = ads8344_adc_conversion(adc, channel->scan_index, - channel->differential); + channel->differential, 0); mutex_unlock(&adc->lock); if (*value < 0) return *value; @@ -155,6 +155,11 @@ static int ads8344_probe(struct spi_device *spi) if (ret) return ret; + /* Do a dummy read and set external clock mode */ + ret = ads8344_adc_conversion(adc, 0, 0, ADS8344_CLOCK_INTERNAL); + if (ret < 0) + return ret; + spi_set_drvdata(spi, indio_dev); ret = iio_device_register(indio_dev);