1 files changed, 54 insertions, 0 deletions
diff --git a/include/linux/pci-pwrctrl.h b/include/linux/pci-pwrctrl.h
new file mode 100644
index 000000000000..7d439b0675e9
--- /dev/null
+++ b/include/linux/pci-pwrctrl.h
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2024 Linaro Ltd.
+ */
+
+#ifndef __PCI_PWRCTRL_H__
+#define __PCI_PWRCTRL_H__
+
+#include <linux/notifier.h>
+#include <linux/workqueue.h>
+
+struct device;
+struct device_link;
+
+/*
+ * This is a simple framework for solving the issue of PCI devices that require
+ * certain resources (regulators, GPIOs, clocks) to be enabled before the
+ * device can actually be detected on the PCI bus.
+ *
+ * The idea is to reuse the platform bus to populate OF nodes describing the
+ * PCI device and its resources, let these platform devices probe and enable
+ * relevant resources and then trigger a rescan of the PCI bus allowing for the
+ * same device (with a second associated struct device) to be registered with
+ * the PCI subsystem.
+ *
+ * To preserve a correct hierarchy for PCI power management and device reset,
+ * we create a device link between the power control platform device (parent)
+ * and the supplied PCI device (child).
+ */
+
+/**
+ * struct pci_pwrctrl - PCI device power control context.
+ * @dev: Address of the power controlling device.
+ *
+ * An object of this type must be allocated by the PCI power control device and
+ * passed to the pwrctrl subsystem to trigger a bus rescan and setup a device
+ * link with the device once it's up.
+ */
+struct pci_pwrctrl {
+	struct device *dev;
+
+	/* Private: don't use. */
+	struct notifier_block nb;
+	struct device_link *link;
+	struct work_struct work;
+};
+
+void pci_pwrctrl_init(struct pci_pwrctrl *pwrctrl, struct device *dev);
+int pci_pwrctrl_device_set_ready(struct pci_pwrctrl *pwrctrl);
+void pci_pwrctrl_device_unset_ready(struct pci_pwrctrl *pwrctrl);
+int devm_pci_pwrctrl_device_set_ready(struct device *dev,
+				     struct pci_pwrctrl *pwrctrl);
+
+#endif /* __PCI_PWRCTRL_H__ */