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: 13219933 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68C06C77B76 for ; Fri, 21 Apr 2023 12:42:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232082AbjDUMmd (ORCPT ); Fri, 21 Apr 2023 08:42:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45148 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232135AbjDUMmb (ORCPT ); Fri, 21 Apr 2023 08:42:31 -0400 Received: from relay2-d.mail.gandi.net (relay2-d.mail.gandi.net [IPv6:2001:4b98:dc4:8::222]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BA63FD309; Fri, 21 Apr 2023 05:42:01 -0700 (PDT) Received: (Authenticated sender: herve.codina@bootlin.com) by mail.gandi.net (Postfix) with ESMTPA id 036DE40004; Fri, 21 Apr 2023 12:41:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1682080915; 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=ecGQES+IctsZxeHGmbZiv99zRKwWx/U6QMun/YsCg54=; b=Y2Uy4aX0fJLJin3UbJuHlp6xKyONaXP+q/4E6traJCaV4jgmMdm3TsvfcgIBmqlsoee0CF zT9VC+AnT8ScfxXu35DaKXKyN6XZvWtUjwQULTMwh1h5C0fRNf2CwmQWLmbfleahnmYjXX SiI8pO1SgPpnwt3yS6RAHsotNbZlJdp3oPLXK5KZudsMH/cQGQy27Yy5X0sWHIZ/BZMdIV h3GITU6Nxe+bCB+QzISMmVKb1l6g/nrEiMkI0RPMX6YxPeQ3ClFV9qjERP4OZmjJCKbKd9 DtCX5vjcjqW7EPRdRpqZLWwK6U9FfWcsg03OZmma3d+DiL2V/zpDZMehsrVBvw== From: Herve Codina To: Herve Codina , Liam Girdwood , Mark Brown , Rob Herring , Krzysztof Kozlowski , Jonathan Cameron , Lars-Peter Clausen , Jaroslav Kysela , Takashi Iwai 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 2/4] iio: inkern: Add a helper to query an available minimum raw value Date: Fri, 21 Apr 2023 14:41:20 +0200 Message-Id: <20230421124122.324820-3-herve.codina@bootlin.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230421124122.324820-1-herve.codina@bootlin.com> References: <20230421124122.324820-1-herve.codina@bootlin.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org 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.