From patchwork Fri Feb 11 16:09:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Srinivas Pandruvada X-Patchwork-Id: 541869 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 BE01BC43219 for ; Fri, 11 Feb 2022 16:09:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350541AbiBKQJp (ORCPT ); Fri, 11 Feb 2022 11:09:45 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:39940 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350462AbiBKQJn (ORCPT ); Fri, 11 Feb 2022 11:09:43 -0500 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A79DFD85; Fri, 11 Feb 2022 08:09:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1644595781; x=1676131781; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=EAVDU/Jvja+puiOGobrPyUB1vzkfjBUp8Z6eMe+Xnaw=; b=A3CuzhKu+EsuGu1u+kwXPiujJRZFlLlITKR104BGjmGU1UsdnZuXmkVS riL2F6naLIPXMEKzO0kdFQwZB0x7p2j3Jrlt4q6My2CeZYE5E4eaiVXp/ jfDOEIr0mu4mj6vvQMxPs0KlRhIXQ60pvGjojy7HGztaC3ClGiGWt3qR8 /irCvrmZSZFr8x85jt2N3Nv2SvuUY3Qqi3mGbPGNDnhOFD4t4Lsuvptac 62axLJU948ryVmvrb/DEGANsb5JqHlTkxq60ZA+QVsjIDHVL6Mg/n/n/P 4Kt0WRVlW7cPAavpk+Cu+jtB8wtHATFMTg8rbxAgUM1KTRGMhJfPfTYgp w==; X-IronPort-AV: E=McAfee;i="6200,9189,10254"; a="249703812" X-IronPort-AV: E=Sophos;i="5.88,361,1635231600"; d="scan'208";a="249703812" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Feb 2022 08:09:39 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,361,1635231600"; d="scan'208";a="630393712" Received: from spandruv-desk.jf.intel.com ([10.54.75.8]) by fmsmga002.fm.intel.com with ESMTP; 11 Feb 2022 08:09:39 -0800 From: Srinivas Pandruvada To: rafael@kernel.org, lenb@kernel.org Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, Srinivas Pandruvada Subject: [PATCH v4 6/6] Documentation/admin-guide/acpi: Add documentation for fine grain control Date: Fri, 11 Feb 2022 08:09:32 -0800 Message-Id: <20220211160932.3221873-7-srinivas.pandruvada@linux.intel.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220211160932.3221873-1-srinivas.pandruvada@linux.intel.com> References: <20220211160932.3221873-1-srinivas.pandruvada@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Add documentation for the newly added attributes: fine_grain_control fan_speed_rpm Signed-off-by: Srinivas Pandruvada --- .../acpi/fan_performance_states.rst | 28 +++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/Documentation/admin-guide/acpi/fan_performance_states.rst b/Documentation/admin-guide/acpi/fan_performance_states.rst index 98fe5c333121..b9e4b4d146c1 100644 --- a/Documentation/admin-guide/acpi/fan_performance_states.rst +++ b/Documentation/admin-guide/acpi/fan_performance_states.rst @@ -60,3 +60,31 @@ For example:: When a given field is not populated or its value provided by the platform firmware is invalid, the "not-defined" string is shown instead of the value. + +ACPI Fan Fine Grain Control +============================= + +When _FIF object specifies support for fine grain control, then fan speed +can be set from 0 to 100% with the recommended minimum "step size" via +_FSL object. User can adjust fan speed using thermal sysfs cooling device. + +Here use can look at fan performance states for a reference speed (speed_rpm) +and set it by changing cooling device cur_state. If the fine grain control +is supported then user can also adjust to some other speeds which are +not defined in the performance states. + +The support of fine grain control is presented via sysfs attribute +"fine_grain_control". If fine grain control is present, this attribute +will show "1" otherwise "0". + +This sysfs attribute is presented in the same directory as performance states. + +ACPI Fan Performance Feedback +============================= + +The optional _FST object provides status information for the fan device. +This includes field to provide current fan speed in revolutions per minute +at which the fan is rotating. + +This speed is presented in the sysfs using the attribute "fan_speed_rpm", +in the same directory as performance states.