From patchwork Fri Apr 21 12:41:20 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Herve Codina X-Patchwork-Id: 676907 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 alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (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 0F183C77B75 for ; Fri, 21 Apr 2023 12:43:50 +0000 (UTC) Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 28E9883E; Fri, 21 Apr 2023 14:42:59 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 28E9883E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1682081029; bh=HSSi6xc2LxgNGOVBIalI3EG83A6fpJXq8GOoVGipEnw=; h=To:Subject:Date:In-Reply-To:References:List-Id:List-Archive: List-Help:List-Owner:List-Post:List-Subscribe:List-Unsubscribe: From:Reply-To:Cc:From; b=fCyyMFf5abxmTrZ3LJwr3FIuYd65q/GdIjTRrMu86QTFRYsXFuOpeZYo2hwqSbo+5 nRI8hYVhzGAZS/TwHMVlxSYfw8cPOz2y/RIauxu+wmasBOsBl3nq3kha1ry5s2kBxF KXYhPdOKUHQbdIfmU97KtoEb1lB/z6xcaEuw7X/w= Received: from mailman-core.alsa-project.org (mailman-core.alsa-project.org [10.254.200.10]) by alsa1.perex.cz (Postfix) with ESMTP id 6666EF8052E; Fri, 21 Apr 2023 14:42:02 +0200 (CEST) To: Herve Codina , Liam Girdwood , Mark Brown , Rob Herring , Krzysztof Kozlowski , Jonathan Cameron , Lars-Peter Clausen , Jaroslav Kysela , Takashi Iwai Subject: [PATCH 2/4] iio: inkern: Add a helper to query an available minimum raw value Date: Fri, 21 Apr 2023 14:41:20 +0200 In-Reply-To: <20230421124122.324820-1-herve.codina@bootlin.com> References: <20230421124122.324820-1-herve.codina@bootlin.com> X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-alsa-devel.alsa-project.org-0; header-match-alsa-devel.alsa-project.org-1; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.8 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <168208092125.26.17592533637486807262@mailman-core.alsa-project.org> X-Patchwork-Original-From: Herve Codina via Alsa-devel From: Herve Codina Reply-To: Herve Codina Cc: alsa-devel@alsa-project.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, Christophe Leroy , Thomas Petazzoni Content-Disposition: inline A helper, iio_read_max_channel_raw() exists to read the available maximum raw value of a channel but nothing similar exists to read the available minimum raw value. This new helper, iio_read_min_channel_raw(), fills the hole and can be used for reading the available minimum raw value of a channel. It is fully based on the existing iio_read_max_channel_raw(). Signed-off-by: Herve Codina --- drivers/iio/inkern.c | 67 ++++++++++++++++++++++++++++++++++++ include/linux/iio/consumer.h | 11 ++++++ 2 files changed, 78 insertions(+) diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c index 872fd5c24147..914fc69c718a 100644 --- a/drivers/iio/inkern.c +++ b/drivers/iio/inkern.c @@ -912,6 +912,73 @@ int iio_read_max_channel_raw(struct iio_channel *chan, int *val) } EXPORT_SYMBOL_GPL(iio_read_max_channel_raw); +static int iio_channel_read_min(struct iio_channel *chan, + int *val, int *val2, int *type, + enum iio_chan_info_enum info) +{ + int unused; + const int *vals; + int length; + int ret; + + if (!val2) + val2 = &unused; + + ret = iio_channel_read_avail(chan, &vals, type, &length, info); + switch (ret) { + case IIO_AVAIL_RANGE: + switch (*type) { + case IIO_VAL_INT: + *val = vals[0]; + break; + default: + *val = vals[0]; + *val2 = vals[1]; + } + return 0; + + case IIO_AVAIL_LIST: + if (length <= 0) + return -EINVAL; + switch (*type) { + case IIO_VAL_INT: + *val = vals[--length]; + while (length) { + if (vals[--length] < *val) + *val = vals[length]; + } + break; + default: + /* FIXME: learn about min for other iio values */ + return -EINVAL; + } + return 0; + + default: + return ret; + } +} + +int iio_read_min_channel_raw(struct iio_channel *chan, int *val) +{ + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev); + int ret; + int type; + + mutex_lock(&iio_dev_opaque->info_exist_lock); + if (!chan->indio_dev->info) { + ret = -ENODEV; + goto err_unlock; + } + + ret = iio_channel_read_min(chan, val, NULL, &type, IIO_CHAN_INFO_RAW); +err_unlock: + mutex_unlock(&iio_dev_opaque->info_exist_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(iio_read_min_channel_raw); + int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type) { struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(chan->indio_dev); diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h index 6802596b017c..956120d8b5a3 100644 --- a/include/linux/iio/consumer.h +++ b/include/linux/iio/consumer.h @@ -297,6 +297,17 @@ int iio_write_channel_raw(struct iio_channel *chan, int val); */ int iio_read_max_channel_raw(struct iio_channel *chan, int *val); +/** + * iio_read_min_channel_raw() - read minimum available raw value from a given + * channel, i.e. the minimum possible value. + * @chan: The channel being queried. + * @val: Value read back. + * + * Note raw reads from iio channels are in adc counts and hence + * scale will need to be applied if standard units are required. + */ +int iio_read_min_channel_raw(struct iio_channel *chan, int *val); + /** * iio_read_avail_channel_raw() - read available raw values from a given channel * @chan: The channel being queried.