From patchwork Fri Aug 16 15:46:14 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Murray X-Patchwork-Id: 11097895 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CA36E1398 for ; Fri, 16 Aug 2019 15:46:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B55AE28640 for ; Fri, 16 Aug 2019 15:46:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A6F99287ED; Fri, 16 Aug 2019 15:46:58 +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=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 5154D28640 for ; Fri, 16 Aug 2019 15:46:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=8eFCAEjNqhGSmnhi7jX3mC1BFHaJ+K9Gpf7Dhl5JGP4=; b=ElDlEYz+J+g6Pf cBteMxM0TlPSfCjQVHEFnS9yqsoRWzKVTcyYZ/56yCHXAkjaWTECiSl5qhISHg08Z2HHVsfK06zOv GN9rDhB2hy9jfh/V38JOv6lsKpoSj7BqgvW4h5b7BsgePBSt8OTqrOR2TTx0KRj9+a11HeZWL/H6G rTf2ZyUoTUZdvapov41k3pZlDloHwaXzbyTB49UqcLmeLDQLhgyGJbHWT0AjtehAnYmhXyCNbXA8c axidzL3bmSaeiCzo6JJ6gr6w8wbzEkDT83/09rpLWcZ4Vg+ZZl8c0OOIUGknbEECsgN0czvhXSneS 66ejgehH9iCLcASQOa2w==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hyeRN-0002P2-TQ; Fri, 16 Aug 2019 15:46:57 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hyeQs-0001qJ-Dp for linux-arm-kernel@lists.infradead.org; Fri, 16 Aug 2019 15:46:27 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C98AF344; Fri, 16 Aug 2019 08:46:25 -0700 (PDT) Received: from e119886-lin.cambridge.arm.com (unknown [10.37.6.20]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1D71D3F694; Fri, 16 Aug 2019 08:46:23 -0700 (PDT) From: Andrew Murray To: Mathieu Poirier , Suzuki K Poulose , Alexander Shishkin Subject: [PATCH v5 2/3] dt-bindings: arm: coresight: Add support for coresight-loses-context-with-cpu Date: Fri, 16 Aug 2019 16:46:14 +0100 Message-Id: <20190816154615.39854-3-andrew.murray@arm.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190816154615.39854-1-andrew.murray@arm.com> References: <20190816154615.39854-1-andrew.murray@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190816_084626_568932_D5D2D7D2 X-CRM114-Status: GOOD ( 10.40 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Al.Grant@arm.com, coresight@lists.linaro.org, Leo Yan , Sudeep Holla , linux-arm-kernel@lists.infradead.org, Mike Leach Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Some coresight components, because of choices made during hardware integration, require their state to be saved and restored across CPU low power states. The software has no reliable method of detecting when save/restore is required thus let's add a binding to inform the kernel. Signed-off-by: Andrew Murray Reviewed-by: Mathieu Poirier Reviewed-by: Suzuki K Poulose --- Documentation/devicetree/bindings/arm/coresight.txt | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/Documentation/devicetree/bindings/arm/coresight.txt b/Documentation/devicetree/bindings/arm/coresight.txt index fcc3bacfd8bc..d02c42d21f2f 100644 --- a/Documentation/devicetree/bindings/arm/coresight.txt +++ b/Documentation/devicetree/bindings/arm/coresight.txt @@ -87,6 +87,15 @@ its hardware characteristcs. * port or ports: see "Graph bindings for Coresight" below. +* Optional properties for all components: + + * arm,coresight-loses-context-with-cpu : boolean. Indicates that the + hardware will lose register context on CPU power down (e.g. CPUIdle). + An example of where this may be needed are systems which contain a + coresight component and CPU in the same power domain. When the CPU + powers down the coresight component also powers down and loses its + context. This property is currently only used for the ETM 4.x driver. + * Optional properties for ETM/PTMs: * arm,cp14: must be present if the system accesses ETM/PTM management