drivers/pci/of.c

   1 /*
   2  * PCI <-> OF mapping helpers
   3  *
   4  * Copyright 2011 IBM Corp.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/irqdomain.h>
  13 #include <linux/kernel.h>
  14 #include <linux/pci.h>
  15 #include <linux/of.h>
  16 #include <linux/of_pci.h>
  17 #include "pci.h"
  18
  19 void pci_set_of_node(struct pci_dev *dev)
  20 {
  21         if (!dev->bus->dev.of_node)
  22                 return;
  23         dev->dev.of_node = of_pci_find_child_device(dev->bus->dev.of_node,
  24                                                     dev->devfn);
  25 }
  26
  27 void pci_release_of_node(struct pci_dev *dev)
  28 {
  29         of_node_put(dev->dev.of_node);
  30         dev->dev.of_node = NULL;
  31 }
  32
  33 void pci_set_bus_of_node(struct pci_bus *bus)
  34 {
  35         if (bus->self == NULL)
  36                 bus->dev.of_node = pcibios_get_phb_of_node(bus);
  37         else
  38                 bus->dev.of_node = of_node_get(bus->self->dev.of_node);
  39 }
  40
  41 void pci_release_bus_of_node(struct pci_bus *bus)
  42 {
  43         of_node_put(bus->dev.of_node);
  44         bus->dev.of_node = NULL;
  45 }
  46
  47 struct device_node * __weak pcibios_get_phb_of_node(struct pci_bus *bus)
  48 {
  49         /* This should only be called for PHBs */
  50         if (WARN_ON(bus->self || bus->parent))
  51                 return NULL;
  52
  53         /* Look for a node pointer in either the intermediary device we
  54          * create above the root bus or it's own parent. Normally only
  55          * the later is populated.
  56          */
  57         if (bus->bridge->of_node)
  58                 return of_node_get(bus->bridge->of_node);
  59         if (bus->bridge->parent && bus->bridge->parent->of_node)
  60                 return of_node_get(bus->bridge->parent->of_node);
  61         return NULL;
  62 }
  63
  64 struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus)
  65 {
  66 #ifdef CONFIG_IRQ_DOMAIN
  67         struct device_node *np;
  68         struct irq_domain *d;
  69
  70         if (!bus->dev.of_node)
  71                 return NULL;
  72
  73         /* Start looking for a phandle to an MSI controller. */
  74         np = of_parse_phandle(bus->dev.of_node, "msi-parent", 0);
  75
  76         /*
  77          * If we don't have an msi-parent property, look for a domain
  78          * directly attached to the host bridge.
  79          */
  80         if (!np)
  81                 np = bus->dev.of_node;
  82
  83         d = irq_find_matching_host(np, DOMAIN_BUS_PCI_MSI);
  84         if (d)
  85                 return d;
  86
  87         return irq_find_host(np);
  88 #else
  89         return NULL;
  90 #endif
  91 }