fdt: Add a function to return PCI BDF triplet
The fdtdec_pci_get_bdf() function returns the bus, device, function
triplet of a PCI device by parsing the "reg" property according to the
PCI device tree binding.
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/include/fdtdec.h b/include/fdtdec.h
index 8b24deb..99cb353 100644
--- a/include/fdtdec.h
+++ b/include/fdtdec.h
@@ -649,4 +649,15 @@
const char *prop_names, const char *name,
struct fdt_resource *res);
+/**
+ * Look at the reg property of a device node that represents a PCI device
+ * and parse the bus, device and function number from it.
+ *
+ * @param fdt FDT blob
+ * @param node node to examine
+ * @param bdf returns bus, device, function triplet
+ * @return 0 if ok, negative on error
+ */
+int fdtdec_pci_get_bdf(const void *fdt, int node, int *bdf);
+
#endif
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index b3c43be..4f66ae1 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -765,4 +765,18 @@
return fdt_get_resource(fdt, node, property, index, res);
}
+
+int fdtdec_pci_get_bdf(const void *fdt, int node, int *bdf)
+{
+ const fdt32_t *prop;
+ int len;
+
+ prop = fdt_getprop(fdt, node, "reg", &len);
+ if (!prop)
+ return len;
+
+ *bdf = fdt32_to_cpu(*prop) & 0xffffff;
+
+ return 0;
+}
#endif