[PATCH v6 2/3] soc: qcom: ice: Enable PM runtime for ICE driver

[Linlin Zhang <linlin.zhang@oss.qualcomm.com>]

The QCOM ICE driver manages the ICE core clock through direct calls to
clk_prepare_enable() and clk_disable_unprepare(), which limits integration
with platforms that rely on firmware-managed resources or platform-specific
power management mechanisms.

Replace direct clock management with runtime PM support by moving clock
enable and disable into runtime PM callbacks. Use
pm_runtime_resume_and_get() and pm_runtime_put_sync() in qcom_ice_resume()
and qcom_ice_suspend() to drive power state transitions, and enable runtime
PM in qcom_ice_probe().

Reviewed-by: Neeraj Soni <neeraj.soni@oss.qualcomm.com>
Reviewed-by: Deepti Jaggi <deepti.jaggi@oss.qualcomm.com>
Signed-off-by: Linlin Zhang <linlin.zhang@oss.qualcomm.com>
---
 drivers/soc/qcom/ice.c | 58 ++++++++++++++++++++++++++++++++++++++----
 1 file changed, 53 insertions(+), 5 deletions(-)

diff --git a/drivers/soc/qcom/ice.c b/drivers/soc/qcom/ice.c
index b203bc685cad..6f9d679b530c 100644
--- a/drivers/soc/qcom/ice.c
+++ b/drivers/soc/qcom/ice.c
@@ -16,6 +16,7 @@
 #include <linux/of.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 
 #include <linux/firmware/qcom/qcom_scm.h>
 
@@ -310,8 +311,8 @@ int qcom_ice_resume(struct qcom_ice *ice)
 	struct device *dev = ice->dev;
 	int err;
 
-	err = clk_prepare_enable(ice->core_clk);
-	if (err) {
+	err = pm_runtime_resume_and_get(dev);
+	if (err < 0) {
 		dev_err(dev, "failed to enable core clock (%d)\n",
 			err);
 		return err;
@@ -323,7 +324,7 @@ EXPORT_SYMBOL_GPL(qcom_ice_resume);
 
 int qcom_ice_suspend(struct qcom_ice *ice)
 {
-	clk_disable_unprepare(ice->core_clk);
+	pm_runtime_put_sync(ice->dev);
 	ice->hwkm_init_complete = false;
 
 	return 0;
@@ -716,24 +717,69 @@ EXPORT_SYMBOL_GPL(devm_of_qcom_ice_get);
 
 static int qcom_ice_probe(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
 	struct qcom_ice *engine;
 	void __iomem *base;
+	int ret;
 
 	base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(base)) {
-		dev_warn(&pdev->dev, "ICE registers not found\n");
+		dev_warn(dev, "ICE registers not found\n");
 		return PTR_ERR(base);
 	}
 
-	engine = qcom_ice_create(&pdev->dev, base);
+	engine = qcom_ice_create(dev, base);
 	if (IS_ERR(engine))
 		return PTR_ERR(engine);
 
 	platform_set_drvdata(pdev, engine);
 
+	ret = devm_pm_runtime_enable(dev);
+	if (ret) {
+		dev_warn(dev, "Enable runtime PM failed, ret: %d\n", ret);
+		return ret;
+	}
+
+	ret = pm_runtime_resume_and_get(dev);
+	if (ret < 0) {
+		dev_warn(dev, "Runtime PM fails to resume, ret: %d\n", ret);
+		return ret;
+	}
+
 	return 0;
 }
 
+static void qcom_ice_remove(struct platform_device *pdev)
+{
+	pm_runtime_put_sync(&pdev->dev);
+}
+
+static int ice_runtime_resume(struct device *dev)
+{
+	struct qcom_ice *ice = dev_get_drvdata(dev);
+	int err = 0;
+
+	err = clk_prepare_enable(ice->core_clk);
+	if (err) {
+		dev_err(dev, "failed to enable core clock (%d)\n",
+			err);
+	}
+
+	return err;
+}
+
+static int ice_runtime_suspend(struct device *dev)
+{
+	struct qcom_ice *ice = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(ice->core_clk);
+	return 0;
+}
+
+static const struct dev_pm_ops ice_pm_ops = {
+	SET_RUNTIME_PM_OPS(ice_runtime_suspend, ice_runtime_resume, NULL)
+};
+
 static const struct of_device_id qcom_ice_of_match_table[] = {
 	{ .compatible = "qcom,inline-crypto-engine" },
 	{ },
@@ -742,8 +788,10 @@ MODULE_DEVICE_TABLE(of, qcom_ice_of_match_table);
 
 static struct platform_driver qcom_ice_driver = {
 	.probe	= qcom_ice_probe,
+	.remove = qcom_ice_remove,
 	.driver = {
 		.name = "qcom-ice",
+		.pm = &ice_pm_ops,
 		.of_match_table = qcom_ice_of_match_table,
 	},
 };
-- 
2.34.1