From patchwork Mon Apr 5 20:42:23 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: 12183571 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, URIBL_BLOCKED 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 17B65C433B4 for ; Mon, 5 Apr 2021 20:42:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C0F42613CD for ; Mon, 5 Apr 2021 20:42:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235624AbhDEUmx (ORCPT ); Mon, 5 Apr 2021 16:42:53 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:37566 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235457AbhDEUmx (ORCPT ); Mon, 5 Apr 2021 16:42:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617655366; 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=Y1fCmnZr6BR8aX0+gHUG0FeM5qO2eDytcn8WJ1wUJsk=; b=LyDPUXSGxT60HCL5lncG6fjZgJdYkENNtgC61eIAqp8fbC+4iGsHLRQrZJUqnmm7v9IVTW 1z9w4tiFUSWxiVW5qm4hpsz5PQGcbbkogdVLOSvGInBxaG0/oTAyifVbo79e3OA/m38hT1 2p7bYok7NntLtVpgb8tG2L3T70yqQAA= 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-439-KFWq2IvDMlKNdJVo7frBUg-1; Mon, 05 Apr 2021 16:42:45 -0400 X-MC-Unique: KFWq2IvDMlKNdJVo7frBUg-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9B67B8030CA; Mon, 5 Apr 2021 20:42:43 +0000 (UTC) Received: from x1.localdomain (ovpn-112-31.ams2.redhat.com [10.36.112.31]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1AEE05D9F0; Mon, 5 Apr 2021 20:42:41 +0000 (UTC) From: Hans de Goede To: Jonathan Cameron Cc: Hans de Goede , Lars-Peter Clausen , Peter Meerwald-Stadler , linux-iio@vger.kernel.org, Dmitry Torokhov , Mark Pearson , Bastien Nocera Subject: [PATCH v2 resend 1/2] iio: documentation: Document proximity sensor label use Date: Mon, 5 Apr 2021 22:42:23 +0200 Message-Id: <20210405204224.18715-2-hdegoede@redhat.com> In-Reply-To: <20210405204224.18715-1-hdegoede@redhat.com> References: <20210405204224.18715-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 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 d957f5da5c04..7379e40d862d 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