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

Jie Gan
2026-04-20T13:29:38Z

On 4/17/2026 3:33 PM, Songwei Chai wrote:
> Add reset node to initialize the value of
> priority/condition_decode/condition_select/timer/counter nodes.
>

LGTM.

Reviewed-by: Jie Gan <jie.gan@oss.qualcomm.com>

> 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,
> };
>