[PATCH v14 7/7] qcom-tgu: Add reset node to initialize

Songwei Chai
2026-04-17T07:35:14Z

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

Signed-off-by: Songwei Chai <songwei.chai@oss.qualcomm.com>
---
.../ABI/testing/sysfs-bus-amba-devices-tgu | 7 ++
drivers/hwtracing/qcom/tgu.c | 74 +++++++++++++++++++
2 files changed, 81 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu b/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu
index 7a3573e03e27..a6b6019c8ef1 100644
--- a/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu
+++ b/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu
@@ -42,3 +42,10 @@ KernelVersion: 7.1
Contact: Jinlong Mao <jinlong.mao@oss.qualcomm.com>, Songwei Chai <songwei.chai@oss.qualcomm.com>
Description:
(RW) Set/Get the counter value with specific step for TGU.
+
+What: /sys/bus/amba/devices/<tgu-name>/reset_tgu
+Date: April 2026
+KernelVersion: 7.1
+Contact: Jinlong Mao <jinlong.mao@oss.qualcomm.com>, Songwei Chai <songwei.chai@oss.qualcomm.com>
+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 6d5bf2621cb0..9fb51f2a912f 100644
--- a/drivers/hwtracing/qcom/tgu.c
+++ b/drivers/hwtracing/qcom/tgu.c
@@ -420,8 +420,82 @@ 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;
+ 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;
+ 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");
+
+ 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