[PATCH v1 2/2] PCI: dw-rockchip: Add runtime PM support to Rockchip PCIe driver

[Anand Moon]

Add runtime power management support to the Rockchip DesignWare PCIe
controller driver by enabling devm_pm_runtime() in the probe function.
These changes allow the PCIe controller to suspend and resume dynamically,
improving power efficiency on supported platforms.

Signed-off-by: Anand Moon <linux.amoon at gmail.com>
---
 drivers/pci/controller/dwc/pcie-dw-rockchip.c | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-dw-rockchip.c b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
index b878ae8e2b3e..5026598d09f8 100644
--- a/drivers/pci/controller/dwc/pcie-dw-rockchip.c
+++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
@@ -20,6 +20,7 @@
 #include <linux/of_irq.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 #include <linux/reset.h>
 
@@ -690,6 +691,20 @@ static int rockchip_pcie_probe(struct platform_device *pdev)
 	if (ret)
 		goto deinit_phy;
 
+	ret = pm_runtime_set_suspended(dev);
+	if (ret)
+		goto disable_pm_runtime;
+
+	ret = devm_pm_runtime_enable(dev);
+	if (ret) {
+		ret = dev_err_probe(dev, ret, "Failed to enable runtime PM\n");
+		goto deinit_clk;
+	}
+
+	ret = pm_runtime_resume_and_get(dev);
+	if (ret)
+		goto disable_pm_runtime;
+
 	switch (data->mode) {
 	case DW_PCIE_RC_TYPE:
 		ret = rockchip_pcie_configure_rc(pdev, rockchip);
@@ -709,7 +724,10 @@ static int rockchip_pcie_probe(struct platform_device *pdev)
 
 	return 0;
 
+disable_pm_runtime:
+	pm_runtime_disable(dev);
 deinit_clk:
+	pm_runtime_no_callbacks(dev);
 	clk_bulk_disable_unprepare(rockchip->clk_cnt, rockchip->clks);
 deinit_phy:
 	rockchip_pcie_phy_deinit(rockchip);
@@ -725,6 +743,9 @@ static void rockchip_pcie_remove(struct platform_device *pdev)
 	/* Perform other cleanups as necessary */
 	clk_bulk_disable_unprepare(rockchip->clk_cnt, rockchip->clks);
 	rockchip_pcie_phy_deinit(rockchip);
+	pm_runtime_put_sync(dev);
+	pm_runtime_disable(dev);
+	pm_runtime_no_callbacks(dev);
 }
 
 static const struct rockchip_pcie_of_data rockchip_pcie_rc_of_data_rk3568 = {
-- 
2.50.1