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authorThierry Reding <thierry.reding@avionic-design.de>2013-05-16 19:55:18 +0400
committerJason Cooper <jason@lakedaemon.net>2013-05-20 00:30:10 +0400
commit45ab9702fb47d18dca116b3a0509efa19fbcb27a (patch)
tree60b73d1c507a8432318e832b5c008e7896ef4e62 /drivers/of
parent29b635c00f3ebcdaf7a52c4948f6d948ad3757d3 (diff)
downloadlinux-45ab9702fb47d18dca116b3a0509efa19fbcb27a.tar.xz
of/pci: Add of_pci_get_devfn() function
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>
Diffstat (limited to 'drivers/of')
-rw-r--r--drivers/of/of_pci.c34
1 files changed, 29 insertions, 5 deletions
diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
index 13e37e2d8ec1..4dd7b9b80076 100644
--- a/drivers/of/of_pci.c
+++ b/drivers/of/of_pci.c
@@ -5,14 +5,15 @@
#include <asm/prom.h>
static inline int __of_pci_pci_compare(struct device_node *node,
- unsigned int devfn)
+ unsigned int data)
{
- unsigned int size;
- const __be32 *reg = of_get_property(node, "reg", &size);
+ int devfn;
- if (!reg || size < 5 * sizeof(__be32))
+ devfn = of_pci_get_devfn(node);
+ if (devfn < 0)
return 0;
- return ((be32_to_cpup(&reg[0]) >> 8) & 0xff) == devfn;
+
+ return devfn == data;
}
struct device_node *of_pci_find_child_device(struct device_node *parent,
@@ -40,3 +41,26 @@ struct device_node *of_pci_find_child_device(struct device_node *parent,
return NULL;
}
EXPORT_SYMBOL_GPL(of_pci_find_child_device);
+
+/**
+ * of_pci_get_devfn() - Get device and function numbers for a device node
+ * @np: device node
+ *
+ * Parses a standard 5-cell PCI resource and returns an 8-bit value that can
+ * be passed to the PCI_SLOT() and PCI_FUNC() macros to extract the device
+ * and function numbers respectively. On error a negative error code is
+ * returned.
+ */
+int of_pci_get_devfn(struct device_node *np)
+{
+ unsigned int size;
+ const __be32 *reg;
+
+ reg = of_get_property(np, "reg", &size);
+
+ if (!reg || size < 5 * sizeof(__be32))
+ return -EINVAL;
+
+ return (be32_to_cpup(reg) >> 8) & 0xff;
+}
+EXPORT_SYMBOL_GPL(of_pci_get_devfn);