From patchwork Wed Aug 18 11:11:26 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miquel Raynal X-Patchwork-Id: 12444007 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=-16.8 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 52C93C43214 for ; Wed, 18 Aug 2021 11:11:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3D5CE610E6 for ; Wed, 18 Aug 2021 11:11:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235459AbhHRLMT (ORCPT ); Wed, 18 Aug 2021 07:12:19 -0400 Received: from relay3-d.mail.gandi.net ([217.70.183.195]:51527 "EHLO relay3-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233798AbhHRLMR (ORCPT ); Wed, 18 Aug 2021 07:12:17 -0400 Received: (Authenticated sender: miquel.raynal@bootlin.com) by relay3-d.mail.gandi.net (Postfix) with ESMTPSA id EEA666000E; Wed, 18 Aug 2021 11:11:41 +0000 (UTC) From: Miquel Raynal To: Jonathan Cameron , Lars-Peter Clausen Cc: Thomas Petazzoni , linux-iio@vger.kernel.org, , Miquel Raynal Subject: [PATCH 03/16] iio: adc: max1027: Push only the requested samples Date: Wed, 18 Aug 2021 13:11:26 +0200 Message-Id: <20210818111139.330636-4-miquel.raynal@bootlin.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20210818111139.330636-1-miquel.raynal@bootlin.com> References: <20210818111139.330636-1-miquel.raynal@bootlin.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org When a triggered scan occurs, the identity of the desired channels is known in indio_dev->active_scan_mask. Instead of reading and pushing to the IIO buffers all channels each time, scan the minimum amount of channels (0 to maximum requested chan, to be exact) and only provide the samples requested by the user. For example, if the user wants channels 1, 4 and 5, all channels from 0 to 5 will be scanned but only the desired channels will be pushed to the IIO buffers. Signed-off-by: Miquel Raynal --- drivers/iio/adc/max1027.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c index b753658bb41e..8ab660f596b5 100644 --- a/drivers/iio/adc/max1027.c +++ b/drivers/iio/adc/max1027.c @@ -360,6 +360,9 @@ static int max1027_set_trigger_state(struct iio_trigger *trig, bool state) struct max1027_state *st = iio_priv(indio_dev); int ret; + if (bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength)) + return -EINVAL; + if (state) { /* Start acquisition on cnvst */ st->reg = MAX1027_SETUP_REG | MAX1027_CKS_MODE0 | @@ -368,9 +371,12 @@ static int max1027_set_trigger_state(struct iio_trigger *trig, bool state) if (ret < 0) return ret; - /* Scan from 0 to max */ - st->reg = MAX1027_CONV_REG | MAX1027_CHAN(0) | - MAX1027_SCAN_N_M | MAX1027_TEMP; + /* + * Scan from 0 to the highest requested channel. The temperature + * could be avoided but it simplifies a bit the logic. + */ + st->reg = MAX1027_CONV_REG | MAX1027_SCAN_0_N | MAX1027_TEMP; + st->reg |= MAX1027_CHAN(fls(*indio_dev->active_scan_mask) - 2); ret = spi_write(st->spi, &st->reg, 1); if (ret < 0) return ret; @@ -391,11 +397,22 @@ static irqreturn_t max1027_trigger_handler(int irq, void *private) struct iio_poll_func *pf = private; struct iio_dev *indio_dev = pf->indio_dev; struct max1027_state *st = iio_priv(indio_dev); + unsigned int scanned_chans = fls(*indio_dev->active_scan_mask); + u16 *buf = st->buffer; + unsigned int bit; pr_debug("%s(irq=%d, private=0x%p)\n", __func__, irq, private); /* fill buffer with all channel */ - spi_read(st->spi, st->buffer, indio_dev->masklength * 2); + spi_read(st->spi, st->buffer, scanned_chans * 2); + + /* Only keep the channels selected by the user */ + for_each_set_bit(bit, indio_dev->active_scan_mask, + indio_dev->masklength) { + if (buf[0] != st->buffer[bit]) + buf[0] = st->buffer[bit]; + buf++; + } iio_push_to_buffers(indio_dev, st->buffer);