This patch adds runtime power management support for platform-based
CoreSight Interconnect TNOC (ITNOC) devices. It introduces suspend and
resume callbacks to manage the APB clock (`pclk`) during device runtime
transitions.

Signed-off-by: Yuanfang Zhang <yuanfang.zhang@oss.qualcomm.com>
---
 drivers/hwtracing/coresight/coresight-tnoc.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight-tnoc.c b/drivers/hwtracing/coresight/coresight-tnoc.c
index 5be882300d79bc0173aa6a19d7da1d48c4aaca9c..2c5370497076536bfa868f0d80db775ef242968b 100644
--- a/drivers/hwtracing/coresight/coresight-tnoc.c
+++ b/drivers/hwtracing/coresight/coresight-tnoc.c
@@ -301,6 +301,28 @@ static void itnoc_remove(struct platform_device *pdev)
 	pm_runtime_disable(&pdev->dev);
 }
 
+#ifdef CONFIG_PM
+static int itnoc_runtime_suspend(struct device *dev)
+{
+	struct trace_noc_drvdata *drvdata = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(drvdata->pclk);
+
+	return 0;
+}
+
+static int itnoc_runtime_resume(struct device *dev)
+{
+	struct trace_noc_drvdata *drvdata = dev_get_drvdata(dev);
+
+	return clk_prepare_enable(drvdata->pclk);
+}
+#endif
+
+static const struct dev_pm_ops itnoc_dev_pm_ops = {
+	SET_RUNTIME_PM_OPS(itnoc_runtime_suspend, itnoc_runtime_resume, NULL)
+};
+
 static const struct of_device_id itnoc_of_match[] = {
 	{ .compatible = "qcom,coresight-itnoc" },
 	{}
@@ -314,6 +336,7 @@ static struct platform_driver itnoc_driver = {
 		.name = "coresight-itnoc",
 		.of_match_table = itnoc_of_match,
 		.suppress_bind_attrs = true,
+		.pm = &itnoc_dev_pm_ops,
 	},
 };
 

-- 
2.34.1

On 9/1/2025 2:58 PM, Yuanfang Zhang wrote:
> This patch adds runtime power management support for platform-based
> CoreSight Interconnect TNOC (ITNOC) devices. It introduces suspend and
> resume callbacks to manage the APB clock (`pclk`) during device runtime
> transitions.
> 
> Signed-off-by: Yuanfang Zhang <yuanfang.zhang@oss.qualcomm.com>
> ---
>  drivers/hwtracing/coresight/coresight-tnoc.c | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
> 
> diff --git a/drivers/hwtracing/coresight/coresight-tnoc.c b/drivers/hwtracing/coresight/coresight-tnoc.c
> index 5be882300d79bc0173aa6a19d7da1d48c4aaca9c..2c5370497076536bfa868f0d80db775ef242968b 100644
> --- a/drivers/hwtracing/coresight/coresight-tnoc.c
> +++ b/drivers/hwtracing/coresight/coresight-tnoc.c
> @@ -301,6 +301,28 @@ static void itnoc_remove(struct platform_device *pdev)
>  	pm_runtime_disable(&pdev->dev);
>  }
>  
> +#ifdef CONFIG_PM
> +static int itnoc_runtime_suspend(struct device *dev)
> +{
> +	struct trace_noc_drvdata *drvdata = dev_get_drvdata(dev);
> +
> +	clk_disable_unprepare(drvdata->pclk);
> +
> +	return 0;
> +}
> +
> +static int itnoc_runtime_resume(struct device *dev)
> +{
> +	struct trace_noc_drvdata *drvdata = dev_get_drvdata(dev);
> +
> +	return clk_prepare_enable(drvdata->pclk);
> +}
> +#endif
> +
> +static const struct dev_pm_ops itnoc_dev_pm_ops = {
> +	SET_RUNTIME_PM_OPS(itnoc_runtime_suspend, itnoc_runtime_resume, NULL)
> +};
> +
>  static const struct of_device_id itnoc_of_match[] = {
>  	{ .compatible = "qcom,coresight-itnoc" },
>  	{}
> @@ -314,6 +336,7 @@ static struct platform_driver itnoc_driver = {
>  		.name = "coresight-itnoc",
>  		.of_match_table = itnoc_of_match,
>  		.suppress_bind_attrs = true,
> +		.pm = &itnoc_dev_pm_ops,
>  	},
>  };
>  
> 

missed Reviewed-by: Leo Yan <leo.yan@arm.com> tag.

thanks,
yuanfang.

Dear all,

Apologies — I mistakenly included an unintended attachment in my previous reply regarding the patch submission.

Please disregard the attachment; it is not relevant to the discussion.

Thank you for your understanding.

Best regards,
Yuanfang Zhang

On 9/1/2025 4:30 PM, yuanfang zhang wrote:
> On 9/1/2025 2:58 PM, Yuanfang Zhang wrote:
>> This patch adds runtime power management support for platform-based
>> CoreSight Interconnect TNOC (ITNOC) devices. It introduces suspend and
>> resume callbacks to manage the APB clock (`pclk`) during device runtime
>> transitions.
>>
>> Signed-off-by: Yuanfang Zhang <yuanfang.zhang@oss.qualcomm.com>
>> ---
>>  drivers/hwtracing/coresight/coresight-tnoc.c | 23 +++++++++++++++++++++++
>>  1 file changed, 23 insertions(+)
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-tnoc.c b/drivers/hwtracing/coresight/coresight-tnoc.c
>> index 5be882300d79bc0173aa6a19d7da1d48c4aaca9c..2c5370497076536bfa868f0d80db775ef242968b 100644
>> --- a/drivers/hwtracing/coresight/coresight-tnoc.c
>> +++ b/drivers/hwtracing/coresight/coresight-tnoc.c
>> @@ -301,6 +301,28 @@ static void itnoc_remove(struct platform_device *pdev)
>>  	pm_runtime_disable(&pdev->dev);
>>  }
>>  
>> +#ifdef CONFIG_PM
>> +static int itnoc_runtime_suspend(struct device *dev)
>> +{
>> +	struct trace_noc_drvdata *drvdata = dev_get_drvdata(dev);
>> +
>> +	clk_disable_unprepare(drvdata->pclk);
>> +
>> +	return 0;
>> +}
>> +
>> +static int itnoc_runtime_resume(struct device *dev)
>> +{
>> +	struct trace_noc_drvdata *drvdata = dev_get_drvdata(dev);
>> +
>> +	return clk_prepare_enable(drvdata->pclk);
>> +}
>> +#endif
>> +
>> +static const struct dev_pm_ops itnoc_dev_pm_ops = {
>> +	SET_RUNTIME_PM_OPS(itnoc_runtime_suspend, itnoc_runtime_resume, NULL)
>> +};
>> +
>>  static const struct of_device_id itnoc_of_match[] = {
>>  	{ .compatible = "qcom,coresight-itnoc" },
>>  	{}
>> @@ -314,6 +336,7 @@ static struct platform_driver itnoc_driver = {
>>  		.name = "coresight-itnoc",
>>  		.of_match_table = itnoc_of_match,
>>  		.suppress_bind_attrs = true,
>> +		.pm = &itnoc_dev_pm_ops,
>>  	},
>>  };
>>  
>>
> 
> missed Reviewed-by: Leo Yan <leo.yan@arm.com> tag.
> 
> thanks,
> yuanfang.