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From:   Tao Zhang <quic_taozha@quicinc.com>
To:     Mathieu Poirier <mathieu.poirier@linaro.org>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Konrad Dybcio <konradybcio@gmail.com>,
        Mike Leach <mike.leach@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
CC:     Tao Zhang <quic_taozha@quicinc.com>,
        Jinlong Mao <quic_jinlmao@quicinc.com>,
        Leo Yan <leo.yan@linaro.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        <coresight@lists.linaro.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <devicetree@vger.kernel.org>,
        Tingwei Zhang <quic_tingweiz@quicinc.com>,
        Yuanfang Zhang <quic_yuanfang@quicinc.com>,
        Trilok Soni <quic_tsoni@quicinc.com>,
        Hao Zhang <quic_hazha@quicinc.com>,
        <linux-arm-msm@vger.kernel.org>, <andersson@kernel.org>
Subject: [PATCH v4 04/11] coresight-tpdm: Add reset node to TPDM node
Date:   Thu, 27 Apr 2023 17:00:30 +0800
Message-ID: <1682586037-25973-5-git-send-email-quic_taozha@quicinc.com>
In-Reply-To: <1682586037-25973-1-git-send-email-quic_taozha@quicinc.com>
References: <1682586037-25973-1-git-send-email-quic_taozha@quicinc.com>
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TPDM device need a node to reset the configurations and status of
it. This change provides a node to reset the configurations and
disable the TPDM if it has been enabled.

Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
---
 .../ABI/testing/sysfs-bus-coresight-devices-tpdm   | 10 ++++++++
 drivers/hwtracing/coresight/coresight-tpdm.c       | 27 ++++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
index 4a58e64..686bdde 100644
--- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
+++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
@@ -11,3 +11,13 @@ Description:
 		Accepts only one of the 2 values -  1 or 2.
 		1 : Generate 64 bits data
 		2 : Generate 32 bits data
+
+What:		/sys/bus/coresight/devices/<tpdm-name>/reset
+Date:		March 2023
+KernelVersion	6.3
+Contact:	Jinlong Mao (QUIC) <quic_jinlmao@quicinc.com>, Tao Zhang (QUIC) <quic_taozha@quicinc.com>
+Description:
+		(Write) Reset the dataset of the tpdm, and disable the tpdm.
+
+		Accepts only one value -  1.
+		1 : Reset the dataset of the tpdm
diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
index 6f8a8ab..2e64cfd 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.c
+++ b/drivers/hwtracing/coresight/coresight-tpdm.c
@@ -164,6 +164,32 @@ static int tpdm_datasets_setup(struct tpdm_drvdata *drvdata)
 	return 0;
 }
 
+static ssize_t reset_store(struct device *dev,
+					  struct device_attribute *attr,
+					  const char *buf,
+					  size_t size)
+{
+	int ret = 0;
+	unsigned long val;
+	struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+	ret = kstrtoul(buf, 10, &val);
+	if (ret || val != 1)
+		return -EINVAL;
+
+	spin_lock(&drvdata->spinlock);
+	tpdm_reset_datasets(drvdata);
+
+	spin_unlock(&drvdata->spinlock);
+
+	/* Disable tpdm if enabled */
+	if (drvdata->enable)
+		coresight_disable_source(drvdata->csdev, NULL);
+
+	return size;
+}
+static DEVICE_ATTR_WO(reset);
+
 /*
  * value 1: 64 bits test data
  * value 2: 32 bits test data
@@ -204,6 +230,7 @@ static ssize_t integration_test_store(struct device *dev,
 static DEVICE_ATTR_WO(integration_test);
 
 static struct attribute *tpdm_attrs[] = {
+	&dev_attr_reset.attr,
 	&dev_attr_integration_test.attr,
 	NULL,
 };
-- 
2.7.4