From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0C1561DB34C; Fri, 4 Apr 2025 11:33:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743766395; cv=none; b=CnxsDhqSz6tdO3fRvpM0cK1YcM0YwhF8p4rfkoErnopFxagZHw37qWLlYpzHRT6/ppTMHfU+Vbu0rZPJmPfiAkndvjBurbs7lWH2ZuKxt9sguVqLzwDEN/h6CuAMu1ZhTk8vx9jRIQZttstkCWHM+Tb1LlODKLtZfllec5QfM4A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743766395; c=relaxed/simple; bh=Vr/dgQUKtxPOzkS4b3b681oYLIy6EF0mAL1Hy8UKmKY=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=b6XxYKGHbpYsRuHbX60xzyHeoeU9opOXRd3zgG3KFWjYGvv1MVocuahdbcZYAD7sujNyF6MsQRcAe01OOrEiJdyOVOofLCOkfAL1aAS1wL6ri5J3LACp2Bv6d6Dq6PgYG1xNDR2iEnUDPCPIbVkn40zuzas/6NAD+SPBBitHVb4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.18.186.31]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4ZTc0D23XVz6L4wP; Fri, 4 Apr 2025 19:32:28 +0800 (CST) Received: from frapeml500008.china.huawei.com (unknown [7.182.85.71]) by mail.maildlp.com (Postfix) with ESMTPS id 7C25B1400D3; Fri, 4 Apr 2025 19:33:10 +0800 (CST) Received: from localhost (10.203.177.66) by frapeml500008.china.huawei.com (7.182.85.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Fri, 4 Apr 2025 13:33:09 +0200 Date: Fri, 4 Apr 2025 12:33:08 +0100 From: Jonathan Cameron To: Gyeyoung Baek CC: , , , , , , , , Subject: Re: [PATCH v1 3/5] ABI: iio: add new ABI doc for mhz19b Message-ID: <20250404123308.00003d72@huawei.com> In-Reply-To: <20250403053225.298308-4-gye976@gmail.com> References: <20250403053225.298308-1-gye976@gmail.com> <20250403053225.298308-4-gye976@gmail.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: lhrpeml500010.china.huawei.com (7.191.174.240) To frapeml500008.china.huawei.com (7.182.85.71) On Thu, 3 Apr 2025 14:32:23 +0900 Gyeyoung Baek wrote: > Add support for winsen MHZ19B CO2 sensor. > > Signed-off-by: Gyeyoung Baek > --- > Documentation/ABI/testing/sysfs-bus-iio-chemical-mhz19b | 7 +++++++ > 1 file changed, 7 insertions(+) > create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-chemical-mhz19b > > diff --git a/Documentation/ABI/testing/sysfs-bus-iio-chemical-mhz19b b/Documentation/ABI/testing/sysfs-bus-iio-chemical-mhz19b > new file mode 100644 > index 000000000000..6cdfd34be016 > --- /dev/null > +++ b/Documentation/ABI/testing/sysfs-bus-iio-chemical-mhz19b > @@ -0,0 +1,7 @@ > +What: /sys/bus/iio/devices/co2_range > +Date: April 2025 > +KernelVersion: 6.14 > +Contact: Gyeyoung Baek > +Description: > + Writing a value adjust maximum measurable PPM. > + should be 2000 or 5000. I haven't checked but assume this also results in a scaling of the measure _raw values? If so the control should be via the standard ABI scale. If you need to be able to establish the range, provide the _available for the _raw via the read_avail() callback and setting appropriate bit in info_mask_separate_available General rule is don't introduce new ABI unless it is impossible to provide the same information via existing interfaces. The decision to use scale rather than range info to control channel scaling was made a very long time ago and having a mixture of the two would make for very complex userspace code. Jonathan > -- > 2.34.1 > >