From patchwork Fri Jun 2 08:41:49 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hao Zhang X-Patchwork-Id: 688895 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 7266CC7EE31 for ; Fri, 2 Jun 2023 08:43:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234724AbjFBInI (ORCPT ); Fri, 2 Jun 2023 04:43:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46520 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234563AbjFBInF (ORCPT ); Fri, 2 Jun 2023 04:43:05 -0400 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3331D1A6; Fri, 2 Jun 2023 01:43:03 -0700 (PDT) Received: from pps.filterd (m0279873.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 3527pmQI007127; Fri, 2 Jun 2023 08:42:48 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=qcppdkim1; bh=df8HITZ3Pr3w5FS83ye95x3aY6DvbRLf3rmUvx5ciCs=; b=ccFAfP3/Y5lSdtvZPMzeTmka4TV/bnrqK8ubgOm8NbDL3cY2ieAYrZAOL9D/yvILpccN cCjAAwRpdgBxiuPmKANjnR3MmTkTowXg01uvC71J/dyF/ofQD+M9Z0Roy82ty7Wfq447 5as5B97iFuKoozb4uZg/OHL+fxIZMekYaMOSZU4IUSu7ORxfIgpkBb80BxrIXQglXE19 KJhWpCyNM24dHbM/MuE8fXpSE9HLoPZ6h1t7vSyoQHdV4ZpRQaXrFyu9Q/VtmsiHS/uH H465fgDhTnCKZ6mBMOuCBmPgoSY4OUvx5V7T+eAMOoRWK7W36dfNcsy4NVUkRZDLb0+T ng== Received: from nasanppmta05.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3qy8390hd6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 02 Jun 2023 08:42:48 +0000 Received: from nasanex01a.na.qualcomm.com (nasanex01a.na.qualcomm.com [10.52.223.231]) by NASANPPMTA05.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 3528glse020237 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 2 Jun 2023 08:42:47 GMT Received: from hazha-gv.qualcomm.com (10.80.80.8) by nasanex01a.na.qualcomm.com (10.52.223.231) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.42; Fri, 2 Jun 2023 01:42:41 -0700 From: Hao Zhang To: Suzuki K Poulose , Mike Leach , Leo Yan , James Clark , Alexander Shishkin , Mathieu Poirier , Konrad Dybcio , "Rob Herring" , Krzysztof Kozlowski , Andy Gross , "Paul Walmsley" , Palmer Dabbelt , Albert Ou , Jonathan Corbet CC: Hao Zhang , Greg Kroah-Hartman , , , , , Tingwei Zhang , Jinlong Mao , Yuanfang Zhang , Tao Zhang , Trilok Soni , , Bjorn Andersson , Subject: [PATCH v6 3/3] Documentation: trace: Add documentation for Coresight Dummy Trace Date: Fri, 2 Jun 2023 16:41:49 +0800 Message-ID: <20230602084149.40031-4-quic_hazha@quicinc.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230602084149.40031-1-quic_hazha@quicinc.com> References: <20230602084149.40031-1-quic_hazha@quicinc.com> MIME-Version: 1.0 X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nasanex01a.na.qualcomm.com (10.52.223.231) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: uPts5TZSDrRxuJTCz1rkGWAS-5snZ2Wi X-Proofpoint-ORIG-GUID: uPts5TZSDrRxuJTCz1rkGWAS-5snZ2Wi X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.957,Hydra:6.0.573,FMLib:17.11.176.26 definitions=2023-06-02_06,2023-05-31_03,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 mlxlogscore=971 mlxscore=0 lowpriorityscore=0 suspectscore=0 phishscore=0 priorityscore=1501 spamscore=0 adultscore=0 malwarescore=0 impostorscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2304280000 definitions=main-2306020064 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Add documentation for Coresight Dummy Trace under trace/coresight. Reviewed-by: Bagas Sanjaya Signed-off-by: Hao Zhang --- .../trace/coresight/coresight-dummy.rst | 32 +++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 Documentation/trace/coresight/coresight-dummy.rst diff --git a/Documentation/trace/coresight/coresight-dummy.rst b/Documentation/trace/coresight/coresight-dummy.rst new file mode 100644 index 000000000000..eff7c553ee6c --- /dev/null +++ b/Documentation/trace/coresight/coresight-dummy.rst @@ -0,0 +1,32 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============================= +Coresight Dummy Trace Module +============================= + + :Author: Hao Zhang + :Date: June 2023 + +Introduction +------------ + +The Coresight dummy trace module is for the specific devices that kernel don't +have permission to access or configure, e.g., CoreSight TPDMs on Qualcomm +platforms. For these devices, a dummy driver is needed to register them as +Coresight devices. The module may also be used to define components that may +not have any programming interfaces, so that paths can be created in the driver. +It provides Coresight API for operations on dummy devices, such as enabling and +disabling them. It also provides the Coresight dummy sink/source paths for +debugging. + +Config details +-------------- + +There are two types of nodes, dummy sink and dummy source. These nodes +are available at ``/sys/bus/coresight/devices``. + +Example output:: + + $ ls -l /sys/bus/coresight/devices | grep dummy + dummy_sink0 -> ../../../devices/platform/soc@0/soc@0:sink/dummy_sink0 + dummy_source0 -> ../../../devices/platform/soc@0/soc@0:source/dummy_source0