phy: xilinx: add runtime PM support

Added Runtime power management support to the xilinx phy driver and using
DEFINE_RUNTIME_DEV_PM_OPS new macros allows the compiler to remove the
unused dev_pm_ops structure and related functions if !CONFIG_PM without
the need to mark the functions __maybe_unused.
Signed-off-by: Piyush Mehta <piyush.mehta@amd.com>
Link: https://lore.kernel.org/r/20230613140250.3018947-2-piyush.mehta@amd.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/xilinx/phy-zynqmp.c

@@ -20,6 +20,7 @@
 #include <linux/of.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/slab.h>
 
 #include <dt-bindings/phy/phy.h>
@@ -820,7 +821,7 @@ static struct phy *xpsgtr_xlate(struct device *dev,
  * Power Management
  */
 
-static int __maybe_unused xpsgtr_suspend(struct device *dev)
+static int xpsgtr_runtime_suspend(struct device *dev)
 {
 	struct xpsgtr_dev *gtr_dev = dev_get_drvdata(dev);
 	unsigned int i;
@@ -835,7 +836,7 @@ static int __maybe_unused xpsgtr_suspend(struct device *dev)
 	return 0;
 }
 
-static int __maybe_unused xpsgtr_resume(struct device *dev)
+static int xpsgtr_runtime_resume(struct device *dev)
 {
 	struct xpsgtr_dev *gtr_dev = dev_get_drvdata(dev);
 	unsigned int icm_cfg0, icm_cfg1;
@@ -876,10 +877,8 @@ static int __maybe_unused xpsgtr_resume(struct device *dev)
 	return err;
 }
 
-static const struct dev_pm_ops xpsgtr_pm_ops = {
-	SET_SYSTEM_SLEEP_PM_OPS(xpsgtr_suspend, xpsgtr_resume)
-};
-
+static DEFINE_RUNTIME_DEV_PM_OPS(xpsgtr_pm_ops, xpsgtr_runtime_suspend,
+				 xpsgtr_runtime_resume, NULL);
 /*
  * Probe & Platform Driver
  */
@@ -1005,6 +1004,16 @@ static int xpsgtr_probe(struct platform_device *pdev)
 		ret = PTR_ERR(provider);
 		goto err_clk_put;
 	}
+
+	pm_runtime_set_active(gtr_dev->dev);
+	pm_runtime_enable(gtr_dev->dev);
+
+	ret = pm_runtime_resume_and_get(gtr_dev->dev);
+	if (ret < 0) {
+		pm_runtime_disable(gtr_dev->dev);
+		goto err_clk_put;
+	}
+
 	return 0;
 
 err_clk_put:
@@ -1014,6 +1023,17 @@ static int xpsgtr_probe(struct platform_device *pdev)
 	return ret;
 }
 
+static int xpsgtr_remove(struct platform_device *pdev)
+{
+	struct xpsgtr_dev *gtr_dev = platform_get_drvdata(pdev);
+
+	pm_runtime_disable(gtr_dev->dev);
+	pm_runtime_put_noidle(gtr_dev->dev);
+	pm_runtime_set_suspended(gtr_dev->dev);
+
+	return 0;
+}
+
 static const struct of_device_id xpsgtr_of_match[] = {
 	{ .compatible = "xlnx,zynqmp-psgtr", },
 	{ .compatible = "xlnx,zynqmp-psgtr-v1.1", },
@@ -1023,10 +1043,11 @@ MODULE_DEVICE_TABLE(of, xpsgtr_of_match);
 
 static struct platform_driver xpsgtr_driver = {
 	.probe = xpsgtr_probe,
+	.remove	= xpsgtr_remove,
 	.driver = {
 		.name = "xilinx-psgtr",
 		.of_match_table	= xpsgtr_of_match,
-		.pm =  &xpsgtr_pm_ops,
+		.pm =  pm_ptr(&xpsgtr_pm_ops),
 	},
 };