path: root/drivers/pci/of.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * PCI <-> OF mapping helpers
 *
 * Copyright 2011 IBM Corp.
 */
#define pr_fmt(fmt)	"PCI: OF: " fmt

#include <linux/cleanup.h>
#include <linux/irqdomain.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
#include <linux/platform_device.h>
#include "pci.h"

#ifdef CONFIG_PCI
/**
 * pci_set_of_node - Find and set device's DT device_node
 * @dev: the PCI device structure to fill
 *
 * Returns 0 on success with of_node set or when no device is described in the
 * DT. Returns -ENODEV if the device is present, but disabled in the DT.
 */
int pci_set_of_node(struct pci_dev *dev)
{
	if (!dev->bus->dev.of_node)
		return 0;

	struct device_node *node __free(device_node) =
		of_pci_find_child_device(dev->bus->dev.of_node, dev->devfn);
	if (!node)
		return 0;

	struct device *pdev __free(put_device) =
		bus_find_device_by_of_node(&platform_bus_type, node);
	if (pdev)
		dev->bus->dev.of_node_reused = true;

	device_set_node(&dev->dev, of_fwnode_handle(no_free_ptr(node)));
	return 0;
}

void pci_release_of_node(struct pci_dev *dev)
{
	of_node_put(dev->dev.of_node);
	device_set_node(&dev->dev, NULL);
}

void pci_set_bus_of_node(struct pci_bus *bus)
{
	struct device_node *node;

	if (bus->self == NULL) {
		node = pcibios_get_phb_of_node(bus);
	} else {
		node = of_node_get(bus->self->dev.of_node);
		if (node && of_property_read_bool(node, "external-facing"))
			bus->self->external_facing = true;
	}

	device_set_node(&bus->dev, of_fwnode_handle(node));
}

void pci_release_bus_of_node(struct pci_bus *bus)
{
	of_node_put(bus->dev.of_node);
	device_set_node(&bus->dev, NULL);
}

struct device_node * __weak pcibios_get_phb_of_node(struct pci_bus *bus)
{
	/* This should only be called for PHBs */
	if (WARN_ON(bus->self || bus->parent))
		return NULL;

	/*
	 * Look for a node pointer in either the intermediary device we
	 * create above the root bus or its own parent. Normally only
	 * the later is populated.
	 */
	if (bus->bridge->of_node)
		return of_node_get(bus->bridge->of_node);
	if (bus->bridge->parent && bus->bridge->parent->of_node)
		return of_node_get(bus->bridge->parent->of_node);
	return NULL;
}

struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus)
{
#ifdef CONFIG_IRQ_DOMAIN
	struct irq_domain *d;

	if (!bus->dev.of_node)
		return NULL;

	/* Start looking for a phandle to an MSI controller. */
	d = of_msi_get_domain(&bus->dev, bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
	if (d)
		return d;

	/*
	 * If we don't have an msi-parent property, look for a domain
	 * directly attached to the host bridge.
	 */
	d = irq_find_matching_host(bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
	if (d)
		return d;

	return irq_find_host(bus->dev.of_node);
#else
	return NULL;
#endif
}

bool pci_host_of_has_msi_map(struct device *dev)
{
	if (dev && dev->of_node)
		return of_get_property(dev->of_node, "msi-map", NULL);
	return false;
}

static inline int __of_pci_pci_compare(struct device_node *node,
				       unsigned int data)
{
	int devfn;

	devfn = of_pci_get_devfn(node);
	if (devfn < 0)
		return 0;

	return devfn == data;
}

struct device_node *of_pci_find_child_device(struct device_node *parent,
					     unsigned int devfn)
{
	struct device_node *node, *node2;

	for_each_child_of_node(parent, node) {
		if (__of_pci_pci_compare(node, devfn))
			return node;
		/*
		 * Some OFs create a parent node "multifunc-device" as
		 * a fake root for all functions of a multi-function
		 * device we go down them as well.
		 */
		if (of_node_name_eq(node, "multifunc-device")) {
			for_each_child_of_node(node, node2) {