PCI/pwrctl: Remove pwrctl device without iterating over all children of pwrctl parent

There is no need to iterate over all children of the pwrctl device parent
to remove the pwrctl device. Since the pwrctl device associated with the
PCI device can be found using of_find_device_by_node() API, use it directly
instead.

Any pwrctl devices lying around without getting associated with the PCI
devices will be removed once their parent device gets removed.

Link: https://lore.kernel.org/r/[email protected]
Tested-by: Bartosz Golaszewski <[email protected]>
Tested-by: Krishna chaitanya chundru <[email protected]>
Signed-off-by: Manivannan Sadhasivam <[email protected]>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <[email protected]>
Signed-off-by: Krzysztof Wilczyński <[email protected]>
Reviewed-by: Bartosz Golaszewski <[email protected]>

Author: Mani-Sadhasivam

drivers/pci/remove.c

@@ -17,25 +17,24 @@ static void pci_free_resources(struct pci_dev *dev)
 	}
 }
 
-static int pci_pwrctl_unregister(struct device *dev, void *data)
+static void pci_pwrctl_unregister(struct device *dev)
 {
-	struct device_node *pci_node = data, *plat_node = dev_of_node(dev);
+	struct platform_device *pdev;
 
-	if (dev_is_platform(dev) && plat_node && plat_node == pci_node) {
-		of_device_unregister(to_platform_device(dev));
-		of_node_clear_flag(plat_node, OF_POPULATED);
-	}
+	pdev = of_find_device_by_node(dev_of_node(dev));
+	if (!pdev)
+		return;
 
-	return 0;
+	of_device_unregister(pdev);
+	of_node_clear_flag(dev_of_node(dev), OF_POPULATED);
 }
 
 static void pci_stop_dev(struct pci_dev *dev)
 {
 	pci_pme_active(dev, false);
 
 	if (pci_dev_is_added(dev)) {
-		device_for_each_child(dev->dev.parent, dev_of_node(&dev->dev),
-				      pci_pwrctl_unregister);
+		pci_pwrctl_unregister(&dev->dev);
 		device_release_driver(&dev->dev);
 		pci_proc_detach_device(dev);
 		pci_remove_sysfs_dev_files(dev);