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_irq.h>
  17 #include <linux/of_pci.h>
  18 #include "pci.h"
  19
  20 void pci_set_of_node(struct pci_dev *dev)
  21 {
  22         if (!dev->bus->dev.of_node)
  23                 return;
  24         dev->dev.of_node = of_pci_find_child_device(dev->bus->dev.of_node,
  25                                                     dev->devfn);
  26 }
  27
  28 void pci_release_of_node(struct pci_dev *dev)
  29 {
  30         of_node_put(dev->dev.of_node);
  31         dev->dev.of_node = NULL;
  32 }
  33
  34 void pci_set_bus_of_node(struct pci_bus *bus)
  35 {
  36         if (bus->self == NULL)
  37                 bus->dev.of_node = pcibios_get_phb_of_node(bus);
  38         else
  39                 bus->dev.of_node = of_node_get(bus->self->dev.of_node);
  40 }
  41
  42 void pci_release_bus_of_node(struct pci_bus *bus)
  43 {
  44         of_node_put(bus->dev.of_node);
  45         bus->dev.of_node = NULL;
  46 }
  47
  48 struct device_node * __weak pcibios_get_phb_of_node(struct pci_bus *bus)
  49 {
  50         /* This should only be called for PHBs */
  51         if (WARN_ON(bus->self || bus->parent))
  52                 return NULL;
  53
  54         /* Look for a node pointer in either the intermediary device we
  55          * create above the root bus or it's own parent. Normally only
  56          * the later is populated.
  57          */
  58         if (bus->bridge->of_node)
  59                 return of_node_get(bus->bridge->of_node);
  60         if (bus->bridge->parent && bus->bridge->parent->of_node)
  61                 return of_node_get(bus->bridge->parent->of_node);
  62         return NULL;
  63 }
  64
  65 struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus)
  66 {
  67 #ifdef CONFIG_IRQ_DOMAIN
  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         d = of_msi_get_domain(&bus->dev, bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
  75         if (d)
  76                 return d;
  77
  78         /*
  79          * If we don't have an msi-parent property, look for a domain
  80          * directly attached to the host bridge.
  81          */
  82         d = irq_find_matching_host(bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
  83         if (d)
  84                 return d;
  85
  86         return irq_find_host(bus->dev.of_node);
  87 #else
  88         return NULL;
  89 #endif
  90 }