From patchwork Mon Feb 15 19:10:02 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 12089123 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0DF30C433E0 for ; Mon, 15 Feb 2021 19:12:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CD44A600EF for ; Mon, 15 Feb 2021 19:12:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229919AbhBOTLp (ORCPT ); Mon, 15 Feb 2021 14:11:45 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:58976 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229890AbhBOTLi (ORCPT ); Mon, 15 Feb 2021 14:11:38 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1613416211; 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; bh=c+1qzMsGah8M2ejfMf/D/kgYFQ8N+9EWXx0ae0goP1E=; b=CF6pxQ3EXd+nJp0gbbr73T4Qg8gw21Ha4haQ3Ahc1tybTMr5NLkMk8/65KdXA8WFvKf7Wt Bf4oIpG2svtkucZBq6HrKGD/Yq/FH5rLSXaH/eFy9MPj2xIhehZavGlNj79UmAfbgD5swc wMRGB8fhbEmQvVH2TVqVYbbeBbhnMxo= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-156-buop7iFKMrmIhtiDUJ1jcA-1; Mon, 15 Feb 2021 14:10:09 -0500 X-MC-Unique: buop7iFKMrmIhtiDUJ1jcA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1985B107ACC7; Mon, 15 Feb 2021 19:10:08 +0000 (UTC) Received: from x1.localdomain (ovpn-115-74.ams2.redhat.com [10.36.115.74]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2AA7D60C15; Mon, 15 Feb 2021 19:10:04 +0000 (UTC) From: Hans de Goede To: Jonathan Cameron Cc: Hans de Goede , Mark Pearson , Bastien Nocera , Dmitry Torokhov , Lars-Peter Clausen , Peter Meerwald-Stadler , linux-iio@vger.kernel.org, Mark Pearson Subject: [PATCH v2 1/2] iio: documentation: Document proximity sensor label use Date: Mon, 15 Feb 2021 20:10:02 +0100 Message-Id: <20210215191003.698888-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org Add an entry to Documentation/ABI/testing/sysfs-bus-iio for the new device label sysfs-attribute support. And document the standardized labels which may be used with proximity sensors to hint userspace about the intended use of the sensor. Using labels to differentiate between the multiple proximity sensors which a modern laptop/tablet may have was discussed in this thread: https://lore.kernel.org/linux-iio/9f9b0ff6-3bf1-63c4-eb36-901cecd7c4d9@redhat.com/ As mentioned there the "proximity-wifi*" labels are already being used in this manner on some chromebooks, see e.g.: arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi arch/arm64/boot/dts/qcom/sc7180-trogdor-lte-sku.dtsi And the "proximity-palmrest" and "proximity-lap" labels are intended to be used with the lap and palmrest sensors found in recent Lenovo ThinkPad models. Cc: Dmitry Torokhov Cc: Mark Pearson Cc: Bastien Nocera Signed-off-by: Hans de Goede --- Changes in v2: - Drop the too generic: What: /sys/bus/iio/devices/iio:deviceX/in_*_label What: /sys/bus/iio/devices/iio:deviceX/out_*_label lines from the newly added documentation, if/when we start using channel-labels with proximity sensors then those should get a separate in_proximityX_label documentation. --- Documentation/ABI/testing/sysfs-bus-iio | 39 +++++++++++++++++++++++++ 1 file changed, 39 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio index 35289d47d6cb..364f842350ab 100644 --- a/Documentation/ABI/testing/sysfs-bus-iio +++ b/Documentation/ABI/testing/sysfs-bus-iio @@ -33,6 +33,45 @@ Description: Description of the physical chip / device for device X. Typically a part number. +What: /sys/bus/iio/devices/iio:deviceX/label +KernelVersion: 5.8 +Contact: linux-iio@vger.kernel.org +Description: + Optional symbolic label for a device. + This is useful for userspace to be able to better identify an + individual device. + + The contents of the label are free-form, but there are some + standardized uses: + + For proximity sensors which give the proximity (of a person) to + a certain wlan or wwan antenna the following standardized labels + are used: + + * "proximity-wifi" + * "proximity-lte" + * "proximity-wifi-lte" + * "proximity-wifi-left" + * "proximity-wifi-right" + + These are used to indicate to userspace that these proximity + sensors may be used to tune transmit power to ensure that + Specific Absorption Rate (SAR) limits are honored. + The "-left" and "-right" labels are for devices with multiple + antennas. + + In some laptops/tablets the standardized proximity sensor labels + instead indicate proximity to a specific part of the device: + + * "proximity-palmrest" indicates proximity to the keyboard's palmrest + * "proximity-palmrest-left" indicates proximity to the left part of the palmrest + * "proximity-palmrest-right" indicates proximity to the right part of the palmrest + * "proximity-lap" indicates the device is being used on someone's lap + + Note "proximity-lap" is special in that its value may be + calculated by firmware from other sensor readings, rather then + being a raw sensor reading. + What: /sys/bus/iio/devices/iio:deviceX/current_timestamp_clock KernelVersion: 4.5 Contact: linux-iio@vger.kernel.org