From patchwork Tue Jul 17 14:19:13 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 10529583 X-Patchwork-Delegate: rjw@sisk.pl Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 455E360545 for ; Tue, 17 Jul 2018 14:21:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2B78B292E0 for ; Tue, 17 Jul 2018 14:21:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2A1E82931A; Tue, 17 Jul 2018 14:21:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A455429322 for ; Tue, 17 Jul 2018 14:21:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731837AbeGQOyX (ORCPT ); Tue, 17 Jul 2018 10:54:23 -0400 Received: from mga12.intel.com ([192.55.52.136]:46685 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731817AbeGQOyW (ORCPT ); Tue, 17 Jul 2018 10:54:22 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Jul 2018 07:20:15 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,365,1526367600"; d="scan'208";a="55017843" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by fmsmga007.fm.intel.com with ESMTP; 17 Jul 2018 07:20:14 -0700 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by paasikivi.fi.intel.com (Postfix) with ESMTPS id D5BC320399; Tue, 17 Jul 2018 17:20:13 +0300 (EEST) Received: from sailus by punajuuri.localdomain with local (Exim 4.89) (envelope-from ) id 1ffQp0-0005tv-LI; Tue, 17 Jul 2018 17:19:22 +0300 From: Sakari Ailus To: linux-acpi@vger.kernel.org Cc: rafael.j.wysocki@intel.com Subject: [PATCH v2 03/11] ACPI / DSD: Document hierarchical data extension references Date: Tue, 17 Jul 2018 17:19:13 +0300 Message-Id: <20180717141921.22625-4-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20180717141921.22625-1-sakari.ailus@linux.intel.com> References: <20180717141921.22625-1-sakari.ailus@linux.intel.com> Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add documentation on how to refer to hierarchical data nodes in a generic way. This brings ACPI to feature parity with Device tree in terms of being able to refer to any node in the tree. Signed-off-by: Sakari Ailus --- Documentation/acpi/dsd/data-node-references.txt | 69 +++++++++++++++++++++++++ 1 file changed, 69 insertions(+) create mode 100644 Documentation/acpi/dsd/data-node-references.txt diff --git a/Documentation/acpi/dsd/data-node-references.txt b/Documentation/acpi/dsd/data-node-references.txt new file mode 100644 index 0000000000000..00c3b5fe1f2ef --- /dev/null +++ b/Documentation/acpi/dsd/data-node-references.txt @@ -0,0 +1,69 @@ +Copyright (C) 2018 Intel Corporation +Author: Sakari Ailus + + +Referencing hierarchical data nodes +----------------------------------- + +ACPI in general allows referring to device objects in the tree only. +Hierarchical data extension nodes may not be referred to directly, hence this +document defines a scheme to implement such references. + +A reference consist of the device object name followed by one or more +hierarchical data extension [1] keys. Specifically, the hierarchical data +extension node which is referred to by the key shall lie directly under the +parent object i.e. either the device object or another hierarchical data +extension node. + +Example +------- + + In the ASL snippet below, the "reference" _DSD property [2] contains a + device object reference to DEV0 and under that device object, a + hierarchical data extension key "node" referring to the NODE object and + lastly, a hierarchical data extension key "anothernode" referring to the + ANOD object which is also the final target of the reference. + + Device (DEV0) + { + Name (_DSD, Package () { + ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"), + Package () { + Package () { "node", NODE }, + } + }) + Name (NODE, Package() { + ToUUID("dbb8e3e6-5886-4ba6-8795-1319f52a966b"), + Package () { + Package () { "anothernode", ANOD }, + } + }) + Name (ANOD, Package() { + ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), + Package () { + Package () { "random-property", 0 }, + } + }) + } + + Device (DEV1) + { + Name (_DSD, Package () { + ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"), + Package () { + Package () { "reference", ^DEV0, "node", "anothernode" }, + } + }) + } + + +References +---------- + +[1] Hierarchical Data Extension UUID For _DSD. + , + referenced 2018-07-17. + +[2] Device Properties UUID For _DSD. + , + referenced 2016-10-04.