From patchwork Sat Apr 22 07:37:14 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hao Zhang X-Patchwork-Id: 676367 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 BC95CC7EE22 for ; Sat, 22 Apr 2023 07:38:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229640AbjDVHiU (ORCPT ); Sat, 22 Apr 2023 03:38:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39598 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229595AbjDVHiO (ORCPT ); Sat, 22 Apr 2023 03:38:14 -0400 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB7B219BD; Sat, 22 Apr 2023 00:38:13 -0700 (PDT) Received: from pps.filterd (m0279871.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 33M7ZNDl027766; Sat, 22 Apr 2023 07:38:01 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=Vsorn17+lHdspdySrV76ro0C+0yMpI5rorINwv56l2o=; b=Cqh2I/ZGB0lsWGyDlTwBA94i0LpeBlbgIYlfdbUNBYfDRfKoDEZCXmeAWc5RJiUmLJve tIyLyWxCGisYt3MIjXogFOl0adbj5LUwhylqKgqZHqcLjjCXayJ8IVufiQEi5yomaspV lKn8nCtSgZOJwwPgCZvvg6KE5bIGky8v7bVd5wO9loHHjtBmN9pBFQPMCr5k3YYdosEp KJdoFHI3MYZjmhJqSxeKD+G3Usp05VxxvlUkw09DT6ymEDnSU0DGb+oRvlOKKRhWHsYX nSlpKKKLUYfeSmWH7TUkM5FHQc7iSvu+Plde3QZC6iRMAVppGrl9p367sEUrr4SRb2Yf 9Q== Received: from nasanppmta03.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3q48h385km-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sat, 22 Apr 2023 07:38:01 +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 33M7bxHq002516 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sat, 22 Apr 2023 07:37:59 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; Sat, 22 Apr 2023 00:37:54 -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 v3 3/3] Documentation: trace: Add documentation for Coresight Dummy Trace Date: Sat, 22 Apr 2023 15:37:14 +0800 Message-ID: <20230422073714.38844-4-quic_hazha@quicinc.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230422073714.38844-1-quic_hazha@quicinc.com> References: <20230422073714.38844-1-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-ORIG-GUID: 3cnXiXHaXM4tSxblUdSU-IzjgEwVrY7R X-Proofpoint-GUID: 3cnXiXHaXM4tSxblUdSU-IzjgEwVrY7R 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=2023-04-21_08,2023-04-21_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=952 mlxscore=0 adultscore=0 priorityscore=1501 impostorscore=0 bulkscore=0 clxscore=1015 lowpriorityscore=0 malwarescore=0 phishscore=0 suspectscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2303200000 definitions=main-2304220064 Precedence: bulk List-ID: X-Mailing-List: devicetree@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..d0f73253f694 --- /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: April 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 + dummy0 -> ../../../devices/platform/soc@0/soc@0:dummy_source/dummy0 + dummy1 -> ../../../devices/platform/soc@0/soc@0:dummy_sink/dummy1