From: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxxxxxxxx>
Bus:Device:Function (BDF) numbers are used to uniquely identify a
device/function on a PCI bus. Hence, add an API to get the BDF from the
devicetree node of a device.
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxxxxxxxx>
---
drivers/pci/of.c | 21 +++++++++++++++++++++
include/linux/of_pci.h | 6 ++++++
2 files changed, 27 insertions(+)
diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index 3579265f119845637e163d9051437c89662762f8..5e584d25434291430145e510b1d49a371dce9165 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -183,6 +183,27 @@ int of_pci_get_devfn(struct device_node *np)
}
EXPORT_SYMBOL_GPL(of_pci_get_devfn);
+/**
+ * of_pci_get_bdf() - Get Bus:Device:Function (BDF) numbers for a device node
+ * @np: device node
+ *
+ * Parses a standard 5-cell PCI resource and returns an 16-bit value that
+ * corresponds to the BDF of the node. On error, a negative error code is
+ * returned.
+ */
+int of_pci_get_bdf(struct device_node *np)
+{
+ u32 reg[5];
+ int error;
+
+ error = of_property_read_u32_array(np, "reg", reg, ARRAY_SIZE(reg));
+ if (error)
+ return error;
+
+ return (reg[0] >> 8) & 0xffff;
+}
+EXPORT_SYMBOL_GPL(of_pci_get_bdf);
+
/**
* of_pci_parse_bus_range() - parse the bus-range property of a PCI device
* @node: device node
diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h
index 29658c0ee71ff10122760214d04ee2bab01709fd..b36ac10653c82f4efdbb57cea56d2ec9d581212f 100644
--- a/include/linux/of_pci.h
+++ b/include/linux/of_pci.h
@@ -12,6 +12,7 @@ struct device_node;
struct device_node *of_pci_find_child_device(struct device_node *parent,
unsigned int devfn);
int of_pci_get_devfn(struct device_node *np);
+int of_pci_get_bdf(struct device_node *np);
void of_pci_check_probe_only(void);
#else
static inline struct device_node *of_pci_find_child_device(struct device_node *parent,
@@ -25,6 +26,11 @@ static inline int of_pci_get_devfn(struct device_node *np)
return -EINVAL;
}
+static inline int of_pci_get_bdf(struct device_node *np)
+{
+ return -EINVAL;
+}
+
static inline void of_pci_check_probe_only(void) { }
#endif
--
2.45.2
