drivers/of/of_pci.c

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