Re: [PATCH v9 7/7] qcom-tgu: Add reset node to initialize
From: Songwei Chai
Date: Tue Jan 06 2026 - 02:22:52 EST
On 12/25/2025 1:56 PM, Jie Gan wrote:
Yeah.>
On 12/19/2025 2:59 PM, Songwei Chai wrote:
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 | 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 010eade0a1c5..0733b3e07b45 100644
--- a/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu
+++ b/Documentation/ABI/testing/sysfs-bus-amba-devices-tgu
@@ -42,3 +42,10 @@ KernelVersion 6.19
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: December 2025
+KernelVersion 6.19
+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 d4210869556e..5a8c6af9b719 100644
--- a/drivers/hwtracing/qcom/tgu.c
+++ b/drivers/hwtracing/qcom/tgu.c
@@ -425,8 +425,82 @@ 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)
+{
+ unsigned long value;
+ struct tgu_drvdata *drvdata = dev_get_drvdata(dev);
+ int i, j, ret;
+
+ if (kstrtoul(buf, 0, &value) || value == 0)
+ return -EINVAL;
+
+ if (!drvdata->enable) {
+ ret = pm_runtime_get_sync(drvdata->dev);
+ if (ret < 0) {
+ pm_runtime_put(drvdata->dev);
+ return ret;
+ }
+ }
+
+ guard(spinlock)(&drvdata->lock);
+ TGU_UNLOCK(drvdata->base);
+
+ writel(0, drvdata->base + TGU_CONTROL);
Better move TGU_LOCK(drvdata->base) here
Thanks,
Jie
+
+ if (drvdata->value_table->priority)
+ memset(drvdata->value_table->priority, 0,
+ MAX_PRIORITY * drvdata->max_step *
+ drvdata->max_reg * sizeof(unsigned int));
+
+ if (drvdata->value_table->condition_decode)
+ memset(drvdata->value_table->condition_decode, 0,
+ drvdata->max_condition_decode * drvdata->max_step *
+ sizeof(unsigned int));
+
+ /* Initialize all condition registers to NOT(value=0x1000000) */
+ for (i = 0; i < drvdata->max_step; i++) {
+ for (j = 0; j < drvdata->max_condition_decode; j++) {
+ drvdata->value_table
+ ->condition_decode[calculate_array_location(
+ drvdata, i, TGU_CONDITION_DECODE, j)] =
+ 0x1000000;
+ }
+ }
+
+ if (drvdata->value_table->condition_select)
+ memset(drvdata->value_table->condition_select, 0,
+ drvdata->max_condition_select * drvdata->max_step *
+ sizeof(unsigned int));
+
+ if (drvdata->value_table->timer)
+ memset(drvdata->value_table->timer, 0,
+ (drvdata->max_step) *
+ (drvdata->max_timer) *
+ sizeof(unsigned int));
+
+ if (drvdata->value_table->counter)
+ memset(drvdata->value_table->counter, 0,
+ (drvdata->max_step) *
+ (drvdata->max_counter) *
+ sizeof(unsigned int));
+
+ dev_dbg(dev, "Coresight-TGU reset complete\n");
+
+ TGU_LOCK(drvdata->base);
+
+ drvdata->enable = false;
+ 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,
};