[PATCH 3/3] coresight-tnoc: Add runtime PM support for Interconnect TNOC

[yuanfang zhang]

On 8/18/2025 10:30 PM, Leo Yan wrote:
> On Fri, Aug 15, 2025 at 06:18:14AM -0700, 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 at oss.qualcomm.com>
>> ---
>>  drivers/hwtracing/coresight/coresight-tnoc.c | 26 ++++++++++++++++++++++++++
>>  1 file changed, 26 insertions(+)
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-tnoc.c b/drivers/hwtracing/coresight/coresight-tnoc.c
>> index aa6f48d838c00d71eff22c18e34e00b93755fd82..f12a1698824bc678545319a3f482fd27e67a7352 100644
>> --- a/drivers/hwtracing/coresight/coresight-tnoc.c
>> +++ b/drivers/hwtracing/coresight/coresight-tnoc.c
>> @@ -270,6 +270,31 @@ 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);
>> +	int ret;
>> +
>> +	ret = clk_prepare_enable(drvdata->pclk);
>> +
>> +	return ret;
> 
> Here can be simplified:
> 
>     return clk_prepare_enable(drvdata->pclk);
> 
sure, will update.
>> +}
>> +#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" },
>>  	{}
>> @@ -282,6 +307,7 @@ static struct platform_driver itnoc_driver = {
>>  	.driver = {
>>  		.name = "coresight-itnoc",
>>  		.of_match_table = itnoc_of_match,
>> +		.pm = &itnoc_dev_pm_ops,
>>  	},
>>  };
>>  
>>
>> -- 
>> 2.34.1
>>
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