linux-kernel - [PATCH v6 2/4] coresight: tpda: add global_flush

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Message-Id: <20251222-add_sysfs_nodes_to_configure_tpda-v6-2-b27143d45c86@oss.qualcomm.com>
Date: Mon, 22 Dec 2025 14:02:22 +0800
From: Jie Gan <jie.gan@....qualcomm.com>
To: Suzuki K Poulose <suzuki.poulose@....com>,
        Mike Leach <mike.leach@...aro.org>,
        James Clark <james.clark@...aro.org>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Tingwei Zhang <tingwei.zhang@....qualcomm.com>
Cc: coresight@...ts.linaro.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, Jie Gan <jie.gan@....qualcomm.com>
Subject: [PATCH v6 2/4] coresight: tpda: add global_flush_req sysfs node

Setting the global_flush_req register to 1 initiates a flush request for
all enabled TPDA input ports. The register remains set until the flush
operation is complete.

Signed-off-by: Jie Gan <jie.gan@....qualcomm.com>
---
 .../ABI/testing/sysfs-bus-coresight-devices-tpda   |  8 ++++
 drivers/hwtracing/coresight/coresight-tpda.c       | 45 ++++++++++++++++++++++
 drivers/hwtracing/coresight/coresight-tpda.h       |  2 +
 3 files changed, 55 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpda b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpda
index 735ce0e494da..c8bc7b19ab25 100644
--- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpda
+++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpda
@@ -33,3 +33,11 @@ Contact:	Jinlong Mao <jinlong.mao@....qualcomm.com>, Tao Zhang <tao.zhang@....qu
 Description:
 		(RW) Configure the CMB/MCMB channel mode for all enabled ports.
 		Value 0 means raw channel mapping mode. Value 1 means channel pair marking mode.
+
+What:		/sys/bus/coresight/devices/<tpda-name>/global_flush_req
+Date:		December 2025
+KernelVersion:	6.19
+Contact:	Jinlong Mao <jinlong.mao@....qualcomm.com>, Tao Zhang <tao.zhang@....qualcomm.com>, Jie Gan <jie.gan@....qualcomm.com>
+Description:
+		(RW) Set global (all ports) flush request bit. The bit remains set until a
+		global flush request sequence completes.
diff --git a/drivers/hwtracing/coresight/coresight-tpda.c b/drivers/hwtracing/coresight/coresight-tpda.c
index 2186223ad33e..d24a9098f1b1 100644
--- a/drivers/hwtracing/coresight/coresight-tpda.c
+++ b/drivers/hwtracing/coresight/coresight-tpda.c
@@ -341,7 +341,52 @@ static ssize_t tpda_trig_sysfs_store(struct device *dev,
 	return size;
 }
 
+static ssize_t global_flush_req_show(struct device *dev,
+				     struct device_attribute *attr,
+				     char *buf)
+{
+	struct tpda_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	unsigned long val;
+
+	if (!drvdata->csdev->refcnt)
+		return -EINVAL;
+
+	guard(spinlock)(&drvdata->spinlock);
+	val = readl_relaxed(drvdata->base + TPDA_CR);
+	/* read global_flush_req bit */
+	val &= TPDA_CR_FLREQ;
+
+	return sysfs_emit(buf, "%lu\n", val);
+}
+
+static ssize_t global_flush_req_store(struct device *dev,
+				      struct device_attribute *attr,
+				      const char *buf,
+				      size_t size)
+{
+	struct tpda_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	unsigned long val;
+
+	if (kstrtoul(buf, 0, &val))
+		return -EINVAL;
+
+	if (!drvdata->csdev->refcnt || !val)
+		return -EINVAL;
+
+	guard(spinlock)(&drvdata->spinlock);
+	val = readl_relaxed(drvdata->base + TPDA_CR);
+	/* set global_flush_req bit */
+	val |= TPDA_CR_FLREQ;
+	CS_UNLOCK(drvdata->base);
+	writel_relaxed(val, drvdata->base + TPDA_CR);
+	CS_LOCK(drvdata->base);
+
+	return size;
+}
+static DEVICE_ATTR_RW(global_flush_req);
+
 static struct attribute *tpda_attrs[] = {
+	&dev_attr_global_flush_req.attr,
 	tpda_trig_sysfs_rw(freq_ts_enable, FREQTS),
 	tpda_trig_sysfs_rw(trig_freq_enable, FRIE),
 	tpda_trig_sysfs_rw(trig_flag_ts_enable, FLRIE),
diff --git a/drivers/hwtracing/coresight/coresight-tpda.h b/drivers/hwtracing/coresight/coresight-tpda.h
index c93732e04af2..1cc9253293ec 100644
--- a/drivers/hwtracing/coresight/coresight-tpda.h
+++ b/drivers/hwtracing/coresight/coresight-tpda.h
@@ -10,6 +10,8 @@
 #define TPDA_Pn_CR(n)		(0x004 + (n * 4))
 #define TPDA_FPID_CR		(0x084)
 
+/* Cross trigger global (all ports) flush request bit */
+#define TPDA_CR_FLREQ		BIT(0)
 /* Cross trigger FREQ packets timestamp bit */
 #define TPDA_CR_FREQTS		BIT(2)
 /* Cross trigger FREQ packet request bit */

-- 
2.34.1