From patchwork Fri May 5 09:24:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hao Zhang X-Patchwork-Id: 679398 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 DFCEEC77B75 for ; Fri, 5 May 2023 09:25:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231550AbjEEJZh (ORCPT ); Fri, 5 May 2023 05:25:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35284 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231702AbjEEJZf (ORCPT ); Fri, 5 May 2023 05:25:35 -0400 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8A38A19415; Fri, 5 May 2023 02:25:34 -0700 (PDT) Received: from pps.filterd (m0279869.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 3457sTZk031532; Fri, 5 May 2023 09:25:22 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=lf38yr2HPtkIr93NPvSpTb0G/h2pVjgRVUdckSYuuQ8=; b=ksV0YRNEm/IJt5oD87fCmCGelJT8N9K6tU8BIZxKUKYVz7NQvDh8xiA9T8stqwc/B9m+ kkTp0/cd0VJ8Qbl0qJxqb5CfU5P6A7NIciFcZOTqn2nAneuwjX7FNSQ5b7QKCr5xuxKy n+XleoInRzl0g+YEOWW5N6xU7DkqYM5+9xOk2NfWdMQCfgiR23khVdRC3xbQY463/icl UX40oZnu5Vd1PJ0RJpqEYvSZ5fS16z3EoeeX1mTp46icoW4sNxJtu48cdDC6bE8QIg7G 1H8RqMDpTELNSXw9srRP4I0c2WTCpULPrdyfivOuNrJHhZEzTI99fsIdgH/5mFRu3kjG WQ== Received: from nasanppmta03.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3qcb24arjd-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 05 May 2023 09:25:22 +0000 Received: from nasanex01a.na.qualcomm.com (nasanex01a.na.qualcomm.com [10.52.223.231]) by NASANPPMTA03.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 3459PLC8026884 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 5 May 2023 09:25:21 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, 5 May 2023 02:25:15 -0700 From: Hao Zhang To: Suzuki K Poulose , Mike Leach , Leo Yan , 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 v4 3/3] Documentation: trace: Add documentation for Coresight Dummy Trace Date: Fri, 5 May 2023 17:24:22 +0800 Message-ID: <20230505092422.32217-4-quic_hazha@quicinc.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230505092422.32217-1-quic_hazha@quicinc.com> References: <20230505092422.32217-1-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: SM7Gnzn-OtCaw7hcWz9pSx3d6kWhIc23 X-Proofpoint-ORIG-GUID: SM7Gnzn-OtCaw7hcWz9pSx3d6kWhIc23 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-05-05_15,2023-05-04_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=967 phishscore=0 impostorscore=0 mlxscore=0 lowpriorityscore=0 bulkscore=0 spamscore=0 priorityscore=1501 malwarescore=0 clxscore=1015 adultscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2303200000 definitions=main-2305050077 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Add documentation for Coresight Dummy Trace under trace/coresight. Signed-off-by: Hao Zhang --- .../trace/coresight/coresight-dummy.rst | 34 +++++++++++++++++++ 1 file changed, 34 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..7cb59f080c88 --- /dev/null +++ b/Documentation/trace/coresight/coresight-dummy.rst @@ -0,0 +1,34 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============================= +Coresight Dummy Trace Module +============================= + + :Author: Hao Zhang + :Date: May 2023 + +Introduction +--------------------------- + +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. So there need driver to register dummy devices +as Coresight devices. It may also be used to define components that +may not have any programming interfaces (e.g, static links), so that +paths can be established in the driver. Provide Coresight API for +dummy device operations, such as enabling and disabling dummy devices. +Build the Coresight path for dummy sink or dummy source for debugging. + +Config details +--------------------------- + +There are two types of nodes, dummy sink and dummy source. The nodes +should be observed at the below coresight path:: + + ``/sys/bus/coresight/devices``. + +e.g.:: + + / $ 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