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
__of_pci_pci_compare(struct device_node * node,unsigned int devfn)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(®[0]) >> 8) & 0xff) == devfn;
16 }
17
of_pci_find_child_device(struct device_node * parent,unsigned int devfn)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);
43