From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 4ECDF2BE7DD; Fri, 22 May 2026 17:47:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779472055; cv=none; b=qFwppx7htxQfwVb4IIVMC9caDJElfqpi3FnMSrPkPY5q9W4hYTlGFYgRkCIytgwyTg5qNP+cPGYoXU+kB2B3nqjmms/J9ixdTV1J67+SRGcFhGZNfzAPsOi2ZAxivJpWMVQvSYI9pRFVWg1BL9+Vp3IXm+iukwh8eNcZkPw5LdI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779472055; c=relaxed/simple; bh=QAsnBcLvhHzJOKM8KliDYC3zKOVCXqFQk+MalyCmSgw=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=YQJMQqEipAuTyIPeijSsRm/Ce/gBhQ8UPVN5BUB9hylePTgU48XNGyTM4usDHypHP5UD5cVPOvUoA9fG2u2UcGNt4oxxFQTt1rJ8I3mFAIvQ8ki88ZQMB6Nnim8Df6cdxO4Mml2WNgdn4b+DOvIg8Eg/dkD9/L1qanlk9Et5QUE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=n9Vf+Chj; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="n9Vf+Chj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C47ED1F000E9; Fri, 22 May 2026 17:47:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779472053; bh=wdOZgX6GWu7ll+GHDji6Q1cRH07Eb0/1T8YPJc+lGRI=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=n9Vf+Chj4dDZA7WEztbYrqM5abCwFZYlJwQbc3/A02XwnezJqBCLELHJiqe2M50dK W6/ySaL2OjUgros64EVhJmDcSxoV3gsSEJUnW202I0ahtBLrIbvovJsdgC7ZdrFcXj 0ANhJmLGg5j1ioMgepa9W4nokanAEzlKaNhJPWuB6tfoe9GQO/fBZiYtYNDiahSRVS 9+pgaufdD1DfEuQPeunOnL3vos8R5JQU5SuYHOtQ4LRFCumuABp5Lc9LzRc9KWeioy SAu4zAzEUub3AGtbog2wO9HugExKT3EfR4aa1AjGvlkXVKZKPXBoh2lIkTpY110m+3 5nJNEDXy9PI3A== Date: Fri, 22 May 2026 18:47:22 +0100 From: Jonathan Cameron To: Rodrigo Alencar via B4 Relay Cc: rodrigo.alencar@analog.com, linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-hardening@vger.kernel.org, Lars-Peter Clausen , Michael Hennerich , David Lechner , Andy Shevchenko , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Philipp Zabel , Jonathan Corbet , Shuah Khan , Kees Cook , "Gustavo A. R. Silva" Subject: Re: [PATCH v5 04/13] Documentation: ABI: testing: add parent entry for iio channels Message-ID: <20260522184722.209f3c96@jic23-huawei> In-Reply-To: <20260517-ad9910-iio-driver-v5-4-31599c88314a@analog.com> References: <20260517-ad9910-iio-driver-v5-0-31599c88314a@analog.com> <20260517-ad9910-iio-driver-v5-4-31599c88314a@analog.com> X-Mailer: Claws Mail 4.4.0 (GTK 3.24.52; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Sun, 17 May 2026 19:37:48 +0100 Rodrigo Alencar via B4 Relay wrote: > From: Rodrigo Alencar > > Add documentation for a read-only sysfs attribute that allows to expose > parent-child relationships between IIO channels. > > Signed-off-by: Rodrigo Alencar > --- > Documentation/ABI/testing/sysfs-bus-iio | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio > index 925a33fd309a..399944974e34 100644 > --- a/Documentation/ABI/testing/sysfs-bus-iio > +++ b/Documentation/ABI/testing/sysfs-bus-iio > @@ -2118,6 +2118,19 @@ Description: > specific attributes. This is useful for userspace to be able to > better identify an individual channel. > > +What: /sys/bus/iio/devices/iio:deviceX/in_voltageY_parent > +What: /sys/bus/iio/devices/iio:deviceX/out_voltageY_parent > +What: /sys/bus/iio/devices/iio:deviceX/in_altvoltageY_parent > +What: /sys/bus/iio/devices/iio:deviceX/out_altvoltageY_parent > +KernelVersion: 7.1 > +Contact: linux-iio@vger.kernel.org > +Description: > + Read-only attribute containing the label of the parent channel > + for hierarchical channel relationships. Only present on channels > + that have a parent channel with a valid label. This is useful for > + userspace to organize channels in tree-like structures that reflects > + the physical or logical relationships between them. Perhaps an example would be useful? Otherwise it seems reasonable. One vague concern I have is maybe we end up with a channel that actually has no other existence than as a parent. Image two signals mixed into one. If that mixed signal has nothing to control it wouldn't normally show up in the ABI. I guess we can give it a label though to ensure there is something there (even when not using labels for this!). J > + > What: /sys/bus/iio/devices/iio:deviceX/in_phaseY_raw > KernelVersion: 4.18 > Contact: linux-iio@vger.kernel.org >