forked from Minki/linux
45ab9702fb
This function can be used to parse the device and function number from a standard 5-cell PCI resource. PCI_SLOT() and PCI_FUNC() can be used on the returned value obtain the device and function numbers respectively. Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Jason Cooper <jason@lakedaemon.net>
67 lines
1.6 KiB
C
67 lines
1.6 KiB
C
#include <linux/kernel.h>
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#include <linux/export.h>
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#include <linux/of.h>
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#include <linux/of_pci.h>
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#include <asm/prom.h>
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static inline int __of_pci_pci_compare(struct device_node *node,
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unsigned int data)
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{
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int devfn;
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devfn = of_pci_get_devfn(node);
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if (devfn < 0)
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return 0;
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return devfn == data;
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}
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struct device_node *of_pci_find_child_device(struct device_node *parent,
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unsigned int devfn)
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{
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struct device_node *node, *node2;
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for_each_child_of_node(parent, node) {
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if (__of_pci_pci_compare(node, devfn))
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return node;
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/*
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* Some OFs create a parent node "multifunc-device" as
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* a fake root for all functions of a multi-function
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* device we go down them as well.
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*/
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if (!strcmp(node->name, "multifunc-device")) {
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for_each_child_of_node(node, node2) {
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if (__of_pci_pci_compare(node2, devfn)) {
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of_node_put(node);
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return node2;
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}
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}
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}
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}
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return NULL;
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}
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EXPORT_SYMBOL_GPL(of_pci_find_child_device);
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/**
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* of_pci_get_devfn() - Get device and function numbers for a device node
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* @np: device node
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*
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* Parses a standard 5-cell PCI resource and returns an 8-bit value that can
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* be passed to the PCI_SLOT() and PCI_FUNC() macros to extract the device
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* and function numbers respectively. On error a negative error code is
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* returned.
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*/
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int of_pci_get_devfn(struct device_node *np)
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{
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unsigned int size;
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const __be32 *reg;
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reg = of_get_property(np, "reg", &size);
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if (!reg || size < 5 * sizeof(__be32))
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return -EINVAL;
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return (be32_to_cpup(reg) >> 8) & 0xff;
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}
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EXPORT_SYMBOL_GPL(of_pci_get_devfn);
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