From patchwork Tue May 23 15:12:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Herve Codina X-Patchwork-Id: 686464 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 1D335C7EE26 for ; Tue, 23 May 2023 15:15:23 +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 47BE4857; Tue, 23 May 2023 17:14:30 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 47BE4857 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1684854920; bh=SWkFMorzUG/B74G+IKL+xq+GSHPrDH7fAwdTOyUk+5k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-Id: List-Archive:List-Help:List-Owner:List-Post:List-Subscribe: List-Unsubscribe:From; b=P8vDyQQ3rlFg/nfjRpu7QJ60ZA6HguskVc27mhRxlgMnN2DmOWOD8H45LMq8XgAf4 U6bLLFsIAzJGlPwufMfjsLe28HNlu/PQ7YFQZfTtFCH+j4mFQ7AqRYA4+Np0M8jcuK lB78IK4hZ59m/hhXNjMspV5Zbh636YU+U25RE+Pc= Received: by alsa1.perex.cz (Postfix, from userid 50401) id 73DFEF805B5; Tue, 23 May 2023 17:12:56 +0200 (CEST) Received: from mailman-core.alsa-project.org (mailman-core.alsa-project.org [10.254.200.10]) by alsa1.perex.cz (Postfix) with ESMTP id 0EEABF805AA; Tue, 23 May 2023 17:12:56 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id C1BEAF805A0; Tue, 23 May 2023 17:12:51 +0200 (CEST) Received: from relay6-d.mail.gandi.net (relay6-d.mail.gandi.net [IPv6:2001:4b98:dc4:8::226]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id B6F4FF8057A for ; Tue, 23 May 2023 17:12:48 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz B6F4FF8057A Authentication-Results: alsa1.perex.cz; dkim=pass (2048-bit key, unprotected) header.d=bootlin.com header.i=@bootlin.com header.a=rsa-sha256 header.s=gm1 header.b=jP6jBYuj Received: (Authenticated sender: herve.codina@bootlin.com) by mail.gandi.net (Postfix) with ESMTPA id E0A95C0003; Tue, 23 May 2023 15:12:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1684854768; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Q6wIbPlk+sj6CdZp+Zuzd40lnLgxHVN50MgCxORNnY8=; b=jP6jBYujyeZx6X332heui2VJL16U7AzCW3vRSIz0ewZFtPtxlyxjZtVeFB8kQkprD8paxU Yr0eWkm1yaW/OOQ6+vlTRY1zscjzVn1COnKeZ4GmVPc3eNVFbJuaSb1l+vwojg3zSloMf3 yIEj34rk/kxXtdQkEODM+DqhBLca6pwBDT+t9e23wopKuP6BqTJ4MoORm6el/gcdZW1V+L ZF2I/SqzRV4SH6nwka6/tzPUwQUsX6mSPhgZSL9HAf2SAPbLbk1dGA7H4ry/qOZlNovOst cysuG+zyzlqXbP3bRZFmE7YApdvmeYBXjnZy/dsTnVxeGZAsXGyuvJp+ad08ug== From: Herve Codina To: Herve Codina , Liam Girdwood , Mark Brown , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Jonathan Cameron , Lars-Peter Clausen , Jaroslav Kysela , Takashi Iwai , Kuninori Morimoto Cc: alsa-devel@alsa-project.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, Christophe Leroy , Thomas Petazzoni Subject: [PATCH v2 5/9] iio: inkern: Add a helper to query an available minimum raw value Date: Tue, 23 May 2023 17:12:19 +0200 Message-Id: <20230523151223.109551-6-herve.codina@bootlin.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230523151223.109551-1-herve.codina@bootlin.com> References: <20230523151223.109551-1-herve.codina@bootlin.com> MIME-Version: 1.0 Message-ID-Hash: FNKNZGU2FBCL7TS2BIDKKJ4FFKSZVYS6 X-Message-ID-Hash: FNKNZGU2FBCL7TS2BIDKKJ4FFKSZVYS6 X-MailFrom: 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: 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 | 70 ++++++++++++++++++++++++++++++++++++ include/linux/iio/consumer.h | 12 +++++++ 2 files changed, 82 insertions(+) diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c index f738db9a0c04..07b26ff8a334 100644 --- a/drivers/iio/inkern.c +++ b/drivers/iio/inkern.c @@ -915,6 +915,76 @@ 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); + if (ret < 0) + return ret; + + 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 -EINVAL; + } +} + +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 f536820b9cf2..e9910b41d48e 100644 --- a/include/linux/iio/consumer.h +++ b/include/linux/iio/consumer.h @@ -301,6 +301,18 @@ 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, if standard units are required, raw reads from iio channels + * need the offset (default 0) and scale (default 1) to be applied + * as (raw + offset) * scale. + */ +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.