PCI/pwrctrl: Rename pwrctl files to pwrctrl

To slightly reduce confusion between "pwrctl" (the power controller and
power sequencing framework) and "bwctrl" (the bandwidth controller),
rename "pwrctl" to "pwrctrl" so they use the same "ctrl" suffix.

Rename drivers/pci/pwrctl/ to drivers/pci/pwrctrl/, including the related
MAINTAINERS, include file (include/linux/pci-pwrctl.h), Makefile, and
Kconfig changes.

This is the minimal rename of files only.  A subsequent commit will rename
functions and data structures.

Link: https://lore.kernel.org/r/20241115214428.2061153-2-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Acked-by: Krzysztof Wilczyński <kw@linux.com>

1 files changed, 147 insertions, 0 deletions

diff --git a/drivers/pci/pwrctrl/core.c b/drivers/pci/pwrctrl/core.c
new file mode 100644
index 000000000000..88f06e9271ba
--- /dev/null
+++ b/drivers/pci/pwrctrl/core.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2024 Linaro Ltd.
+ */
+
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/pci-pwrctrl.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+
+static int pci_pwrctl_notify(struct notifier_block *nb, unsigned long action,
+			     void *data)
+{
+	struct pci_pwrctl *pwrctl = container_of(nb, struct pci_pwrctl, nb);
+	struct device *dev = data;
+
+	if (dev_fwnode(dev) != dev_fwnode(pwrctl->dev))
+		return NOTIFY_DONE;
+
+	switch (action) {
+	case BUS_NOTIFY_ADD_DEVICE:
+		/*
+		 * We will have two struct device objects bound to two different
+		 * drivers on different buses but consuming the same DT node. We
+		 * must not bind the pins twice in this case but only once for
+		 * the first device to be added.
+		 *
+		 * If we got here then the PCI device is the second after the
+		 * power control platform device. Mark its OF node as reused.
+		 */
+		dev->of_node_reused = true;
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static void rescan_work_func(struct work_struct *work)
+{
+	struct pci_pwrctl *pwrctl = container_of(work, struct pci_pwrctl, work);
+
+	pci_lock_rescan_remove();
+	pci_rescan_bus(to_pci_dev(pwrctl->dev->parent)->bus);
+	pci_unlock_rescan_remove();
+}
+
+/**
+ * pci_pwrctl_init() - Initialize the PCI power control context struct
+ *
+ * @pwrctl: PCI power control data
+ * @dev: Parent device
+ */
+void pci_pwrctl_init(struct pci_pwrctl *pwrctl, struct device *dev)
+{
+	pwrctl->dev = dev;
+	INIT_WORK(&pwrctl->work, rescan_work_func);
+}
+EXPORT_SYMBOL_GPL(pci_pwrctl_init);
+
+/**
+ * pci_pwrctl_device_set_ready() - Notify the pwrctl subsystem that the PCI
+ * device is powered-up and ready to be detected.
+ *
+ * @pwrctl: PCI power control data.
+ *
+ * Returns:
+ * 0 on success, negative error number on error.
+ *
+ * Note:
+ * This function returning 0 doesn't mean the device was detected. It means,
+ * that the bus rescan was successfully started. The device will get bound to
+ * its PCI driver asynchronously.
+ */
+int pci_pwrctl_device_set_ready(struct pci_pwrctl *pwrctl)
+{
+	int ret;
+
+	if (!pwrctl->dev)
+		return -ENODEV;
+
+	pwrctl->nb.notifier_call = pci_pwrctl_notify;
+	ret = bus_register_notifier(&pci_bus_type, &pwrctl->nb);
+	if (ret)
+		return ret;
+
+	schedule_work(&pwrctl->work);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pci_pwrctl_device_set_ready);
+
+/**
+ * pci_pwrctl_device_unset_ready() - Notify the pwrctl subsystem that the PCI
+ * device is about to be powered-down.
+ *
+ * @pwrctl: PCI power control data.
+ */
+void pci_pwrctl_device_unset_ready(struct pci_pwrctl *pwrctl)
+{
+	/*
+	 * We don't have to delete the link here. Typically, this function
+	 * is only called when the power control device is being detached. If
+	 * it is being detached then the child PCI device must have already
+	 * been unbound too or the device core wouldn't let us unbind.
+	 */
+	bus_unregister_notifier(&pci_bus_type, &pwrctl->nb);
+}
+EXPORT_SYMBOL_GPL(pci_pwrctl_device_unset_ready);
+
+static void devm_pci_pwrctl_device_unset_ready(void *data)
+{
+	struct pci_pwrctl *pwrctl = data;
+
+	pci_pwrctl_device_unset_ready(pwrctl);
+}
+
+/**
+ * devm_pci_pwrctl_device_set_ready - Managed variant of
+ * pci_pwrctl_device_set_ready().
+ *
+ * @dev: Device managing this pwrctl provider.
+ * @pwrctl: PCI power control data.
+ *
+ * Returns:
+ * 0 on success, negative error number on error.
+ */
+int devm_pci_pwrctl_device_set_ready(struct device *dev,
+				     struct pci_pwrctl *pwrctl)
+{
+	int ret;
+
+	ret = pci_pwrctl_device_set_ready(pwrctl);
+	if (ret)
+		return ret;
+
+	return devm_add_action_or_reset(dev,
+					devm_pci_pwrctl_device_unset_ready,
+					pwrctl);
+}
+EXPORT_SYMBOL_GPL(devm_pci_pwrctl_device_set_ready);
+
+MODULE_AUTHOR("Bartosz Golaszewski <bartosz.golaszewski@linaro.org>");
+MODULE_DESCRIPTION("PCI Device Power Control core driver");
+MODULE_LICENSE("GPL");