Root/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
7static 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
18struct 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}
42EXPORT_SYMBOL_GPL(of_pci_find_child_device);
43

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