[PATCH v11 7/7] qcom-tgu: Add reset node to initialize

[Songwei Chai]

Add reset node to initialize the value of
priority/condition_decode/condition_select/timer/counter nodes.

Signed-off-by: Songwei Chai <songwei.chai@xxxxxxxxxxxxxxxx>
---
 .../ABI/testing/sysfs-bus-amba-devices-tgu    |  7 ++
 drivers/hwtracing/qcom/tgu.c                  | 77 +++++++++++++++++++
 2 files changed, 84 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu b/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu
index 9daacd68eed0..3ff34a769d94 100644
--- a/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu
+++ b/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu
@@ -42,3 +42,10 @@ KernelVersion	6.20
 Contact:	Jinlong Mao <jinlong.mao@xxxxxxxxxxxxxxxx>, Songwei Chai <songwei.chai@xxxxxxxxxxxxxxxx>
 Description:
 		(RW) Set/Get the counter value with specific step for TGU.
+
+What:		/sys/bus/amba/devices/<tgu-name>/reset_tgu
+Date:		February 2026
+KernelVersion	6.20
+Contact:	Jinlong Mao <jinlong.mao@xxxxxxxxxxxxxxxx>, Songwei Chai <songwei.chai@xxxxxxxxxxxxxxxx>
+Description:
+		(Write) Write 1 to reset the dataset for TGU.
diff --git a/drivers/hwtracing/qcom/tgu.c b/drivers/hwtracing/qcom/tgu.c
index 4539415571f6..e28e6d27cf56 100644
--- a/drivers/hwtracing/qcom/tgu.c
+++ b/drivers/hwtracing/qcom/tgu.c
@@ -410,8 +410,85 @@ static ssize_t enable_tgu_store(struct device *dev,
 }
 static DEVICE_ATTR_RW(enable_tgu);
 
+/* reset_tgu_store - Reset Trace and Gating Unit (TGU) configuration. */
+static ssize_t reset_tgu_store(struct device *dev,
+			       struct device_attribute *attr, const char *buf,
+			       size_t size)
+{
+	struct tgu_drvdata *drvdata = dev_get_drvdata(dev);
+	struct value_table *vt = drvdata->value_table;
+	u32 *cond_decode = drvdata->value_table->condition_decode;
+	bool need_pm_put = false;
+	unsigned long value;
+	int i, j, ret;
+
+	if (kstrtoul(buf, 0, &value) || value != 1)
+		return -EINVAL;
+
+	spin_lock(&drvdata->lock);
+	if (!drvdata->enabled) {
+		spin_unlock(&drvdata->lock);
+		ret = pm_runtime_resume_and_get(drvdata->dev);
+		if (ret)
+			return ret;
+		need_pm_put = true;
+		spin_lock(&drvdata->lock);
+	}
+
+	tgu_do_disable(drvdata);
+
+	if (vt->priority) {
+		size_t size = MAX_PRIORITY * drvdata->num_step *
+				drvdata->num_reg * sizeof(unsigned int);
+		memset(vt->priority, 0, size);
+	}
+
+	if (vt->condition_decode) {
+		size_t size = drvdata->num_condition_decode *
+			      drvdata->num_step * sizeof(unsigned int);
+		memset(vt->condition_decode, 0, size);
+	}
+
+	/* Initialize all condition registers to NOT(value=0x1000000) */
+	for (i = 0; i < drvdata->num_step; i++) {
+		for (j = 0; j < drvdata->num_condition_decode; j++) {
+			cond_decode[calculate_array_location(drvdata, i,
+			TGU_CONDITION_DECODE, j)] = 0x1000000;
+		}
+	}
+
+	if (vt->condition_select) {
+		size_t size = drvdata->num_condition_select *
+			      drvdata->num_step * sizeof(unsigned int);
+		memset(vt->condition_select, 0, size);
+	}
+
+	if (vt->timer) {
+		size_t size = (drvdata->num_step) * (drvdata->num_timer) *
+				sizeof(unsigned int);
+		memset(vt->timer, 0, size);
+	}
+
+	if (vt->counter) {
+		size_t size = (drvdata->num_step) * (drvdata->num_counter) *
+			      sizeof(unsigned int);
+		memset(vt->counter, 0, size);
+	}
+
+	spin_unlock(&drvdata->lock);
+
+	dev_dbg(dev, "Qualcomm-TGU reset complete\n");
+
+	if (need_pm_put)
+		pm_runtime_put(drvdata->dev);
+
+	return size;
+}
+static DEVICE_ATTR_WO(reset_tgu);
+
 static struct attribute *tgu_common_attrs[] = {
 	&dev_attr_enable_tgu.attr,
+	&dev_attr_reset_tgu.attr,
 	NULL,
 };
 
-- 
2.34.1