Merge branch 'pci/pwrctl'

- Use of_platform_device_create() instead of of_platform_populate() to
  create pwrctl platform devices so we can control it based on the child
  nodes (Manivannan Sadhasivam)

- Create pwrctrl platform devices only if there's a relevant power supply
  property (Manivannan Sadhasivam)

- Add device link from the pwrctl supplier to the PCI dev to ensure pwrctl
  drivers are probed before the PCI dev driver; this avoids a race where
  pwrctl could change device power state while the PCI driver was active
  (Manivannan Sadhasivam)

- Find pwrctl device for removal with of_find_device_by_node() instead of
  searching all children of the parent (Manivannan Sadhasivam)

- Rename 'pwrctl' to 'pwrctrl' to use the same 'ctrl' suffix as 'bwctrl'
  and other PCI files to reduce confusion (Bjorn Helgaas)

* pci/pwrctl:
  PCI/pwrctrl: Rename pwrctrl functions and structures
  PCI/pwrctrl: Rename pwrctl files to pwrctrl
  PCI/pwrctl: Remove pwrctl device without iterating over all children of pwrctl parent
  PCI/pwrctl: Ensure that pwrctl drivers are probed before PCI client drivers
  PCI/pwrctl: Create pwrctl device only if at least one power supply is present
  PCI/pwrctl: Use of_platform_device_create() to create pwrctl devices

# Conflicts:
#	drivers/pci/bus.c
#	drivers/pci/remove.c

Author: bjorn-helgaas

MAINTAINERS

@@ -17916,8 +17916,8 @@ M:	Bartosz Golaszewski <brgl@bgdev.pl>
 L:	linux-pci@vger.kernel.org
 S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git
-F:	drivers/pci/pwrctl/*
-F:	include/linux/pci-pwrctl.h
+F:	drivers/pci/pwrctrl/*
+F:	include/linux/pci-pwrctrl.h
 
 PCI SUBSYSTEM
 M:	Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/Kconfig

@@ -305,6 +305,6 @@ source "drivers/pci/hotplug/Kconfig"
 source "drivers/pci/controller/Kconfig"
 source "drivers/pci/endpoint/Kconfig"
 source "drivers/pci/switch/Kconfig"
-source "drivers/pci/pwrctl/Kconfig"
+source "drivers/pci/pwrctrl/Kconfig"
 
 endif

drivers/pci/Makefile

@@ -9,7 +9,7 @@ obj-$(CONFIG_PCI)		+= access.o bus.o probe.o host-bridge.o \
 
 obj-$(CONFIG_PCI)		+= msi/
 obj-$(CONFIG_PCI)		+= pcie/
-obj-$(CONFIG_PCI)		+= pwrctl/
+obj-$(CONFIG_PCI)		+= pwrctrl/
 
 ifdef CONFIG_PCI
 obj-$(CONFIG_PROC_FS)		+= proc.o

drivers/pci/bus.c

@@ -13,6 +13,7 @@
 #include <linux/ioport.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
+#include <linux/platform_device.h>
 #include <linux/proc_fs.h>
 #include <linux/slab.h>
 
@@ -330,6 +331,47 @@ void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { }
 
 void __weak pcibios_bus_add_device(struct pci_dev *pdev) { }
 
+/*
+ * Create pwrctrl devices (if required) for the PCI devices to handle the power
+ * state.
+ */
+static void pci_pwrctrl_create_devices(struct pci_dev *dev)
+{
+	struct device_node *np = dev_of_node(&dev->dev);
+	struct device *parent = &dev->dev;
+	struct platform_device *pdev;
+
+	/*
+	 * First ensure that we are starting from a PCI bridge and it has a
+	 * corresponding devicetree node.
+	 */
+	if (np && pci_is_bridge(dev)) {
+		/*
+		 * Now look for the child PCI device nodes and create pwrctrl
+		 * devices for them. The pwrctrl device drivers will manage the
+		 * power state of the devices.
+		 */
+		for_each_available_child_of_node_scoped(np, child) {
+			/*
+			 * First check whether the pwrctrl device really
+			 * needs to be created or not. This is decided
+			 * based on at least one of the power supplies
+			 * being defined in the devicetree node of the
+			 * device.
+			 */
+			if (!of_pci_supply_present(child)) {
+				pci_dbg(dev, "skipping OF node: %s\n", child->name);
+				return;
+			}
+
+			/* Now create the pwrctrl device */
+			pdev = of_platform_device_create(child, NULL, parent);
+			if (!pdev)
+				pci_err(dev, "failed to create OF node: %s\n", child->name);
+		}
+	}
+}
+
 /**
  * pci_bus_add_device - start driver for a single device
  * @dev: device to add
@@ -339,6 +381,7 @@ void __weak pcibios_bus_add_device(struct pci_dev *pdev) { }
 void pci_bus_add_device(struct pci_dev *dev)
 {
 	struct device_node *dn = dev->dev.of_node;
+	struct platform_device *pdev;
 	int retval;
 
 	/*
@@ -353,20 +396,28 @@ void pci_bus_add_device(struct pci_dev *dev)
 	pci_proc_attach_device(dev);
 	pci_bridge_d3_update(dev);
 
+	pci_pwrctrl_create_devices(dev);
+
+	/*
+	 * If the PCI device is associated with a pwrctrl device with a
+	 * power supply, create a device link between the PCI device and
+	 * pwrctrl device.  This ensures that pwrctrl drivers are probed
+	 * before PCI client drivers.
+	 */
+	pdev = of_find_device_by_node(dn);
+	if (pdev && of_pci_supply_present(dn)) {
+		if (!device_link_add(&dev->dev, &pdev->dev,
+				     DL_FLAG_AUTOREMOVE_CONSUMER))
+			pci_err(dev, "failed to add device link to power control device %s\n",
+				pdev->name);
+	}
+
 	dev->match_driver = !dn || of_device_is_available(dn);
 	retval = device_attach(&dev->dev);
 	if (retval < 0 && retval != -EPROBE_DEFER)
 		pci_warn(dev, "device attach failed (%d)\n", retval);
 
 	pci_dev_assign_added(dev);
-
-	if (dev_of_node(&dev->dev) && pci_is_bridge(dev)) {
-		retval = of_platform_populate(dev_of_node(&dev->dev), NULL, NULL,
-					      &dev->dev);
-		if (retval)
-			pci_err(dev, "failed to populate child OF nodes (%d)\n",
-				retval);
-	}
 }
 EXPORT_SYMBOL_GPL(pci_bus_add_device);
 

drivers/pci/of.c

@@ -728,6 +728,33 @@ void of_pci_make_dev_node(struct pci_dev *pdev)
 }
 #endif
 
+/**
+ * of_pci_supply_present() - Check if the power supply is present for the PCI
+ *				device
+ * @np: Device tree node
+ *
+ * Check if the power supply for the PCI device is present in the device tree
+ * node or not.
+ *
+ * Return: true if at least one power supply exists; false otherwise.
+ */
+bool of_pci_supply_present(struct device_node *np)
+{
+	struct property *prop;
+	char *supply;
+
+	if (!np)
+		return false;
+
+	for_each_property_of_node(np, prop) {
+		supply = strrchr(prop->name, '-');
+		if (supply && !strcmp(supply, "-supply"))
+			return true;
+	}
+
+	return false;
+}
+
 #endif /* CONFIG_PCI */
 
 /**

drivers/pci/pci.h

@@ -797,6 +797,7 @@ void pci_set_bus_of_node(struct pci_bus *bus);
 void pci_release_bus_of_node(struct pci_bus *bus);
 
 int devm_of_pci_bridge_init(struct device *dev, struct pci_host_bridge *bridge);
+bool of_pci_supply_present(struct device_node *np);
 
 #else
 static inline int
@@ -844,6 +845,10 @@ static inline int devm_of_pci_bridge_init(struct device *dev, struct pci_host_br
 	return 0;
 }
 
+static inline bool of_pci_supply_present(struct device_node *np)
+{
+	return false;
+}
 #endif /* CONFIG_OF */
 
 struct of_changeset;

drivers/pci/pwrctl/Makefile

@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_PCI_PWRCTL)		+= pci-pwrctrl-core.o
+pci-pwrctrl-core-y			:= core.o
+
+obj-$(CONFIG_PCI_PWRCTL_PWRSEQ)		+= pci-pwrctrl-pwrseq.o