From: Yuanfang Zhang <yuanfang.zhang@oss.qualcomm.com>
Date: Thu, 4 Dec 2025 04:43:09 +0000 (-0800)
Subject: coresight-tnoc: Add runtime PM support for Interconnect TNOC
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4d9024d14d1bacb097f33ef7d3ed1696d6a46c88;p=thirdparty%2Fkernel%2Flinux.git

coresight-tnoc: Add runtime PM support for Interconnect TNOC

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>
Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20251203-itnoc-v5-3-5b97c63f2268@oss.qualcomm.com
---

diff --git a/drivers/hwtracing/coresight/coresight-tnoc.c b/drivers/hwtracing/coresight/coresight-tnoc.c
index affd8204b534..1128612e70a7 100644
--- a/drivers/hwtracing/coresight/coresight-tnoc.c
+++ b/drivers/hwtracing/coresight/coresight-tnoc.c
@@ -305,6 +305,28 @@ 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" },
 	{}
@@ -318,6 +340,7 @@ static struct platform_driver itnoc_driver = {
 		.name = "coresight-itnoc",
 		.of_match_table = itnoc_of_match,
 		.suppress_bind_attrs = true,
+		.pm = &itnoc_dev_pm_ops,
 	},
 };