drivers/of/of_pci.c

   1 #include <linux/kernel.h>
   2 #include <linux/of.h>
   3 #include <linux/of_pci.h>
   4 #include <asm/prom.h>
   5
   6 static inline int __of_pci_pci_compare(struct device_node *node,
   7                                        unsigned int devfn)
   8 {
   9         unsigned int size;
  10         const __be32 *reg = of_get_property(node, "reg", &size);
  11
  12         if (!reg || size < 5 * sizeof(__be32))
  13                 return 0;
  14         return ((be32_to_cpup(&reg[0]) >> 8) & 0xff) == devfn;
  15 }
  16
  17 struct device_node *of_pci_find_child_device(struct device_node *parent,
  18                                              unsigned int devfn)
  19 {
  20         struct device_node *node, *node2;
  21
  22         for_each_child_of_node(parent, node) {
  23                 if (__of_pci_pci_compare(node, devfn))
  24                         return node;
  25                 /*
  26                  * Some OFs create a parent node "multifunc-device" as
  27                  * a fake root for all functions of a multi-function
  28                  * device we go down them as well.
  29                  */
  30                 if (!strcmp(node->name, "multifunc-device")) {
  31                         for_each_child_of_node(node, node2) {
  32                                 if (__of_pci_pci_compare(node2, devfn)) {
  33                                         of_node_put(node);
  34                                         return node2;
  35                                 }
  36                         }
  37                 }
  38         }
  39         return NULL;
  40 }
  41 EXPORT_SYMBOL_GPL(of_pci_find_child_device);