v4.19.13 snapshot.
diff --git a/arch/powerpc/sysdev/mpc5xxx_clocks.c b/arch/powerpc/sysdev/mpc5xxx_clocks.c
new file mode 100644
index 0000000..834a6d7
--- /dev/null
+++ b/arch/powerpc/sysdev/mpc5xxx_clocks.c
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * mpc5xxx_get_bus_frequency - Find the bus frequency for a device
+ * @node: device node
+ *
+ * Returns bus frequency (IPS on MPC512x, IPB on MPC52xx),
+ * or 0 if the bus frequency cannot be found.
+ */
+
+#include <linux/kernel.h>
+#include <linux/of_platform.h>
+#include <linux/export.h>
+#include <asm/mpc5xxx.h>
+
+unsigned long mpc5xxx_get_bus_frequency(struct device_node *node)
+{
+ const unsigned int *p_bus_freq = NULL;
+
+ of_node_get(node);
+ while (node) {
+ p_bus_freq = of_get_property(node, "bus-frequency", NULL);
+ if (p_bus_freq)
+ break;
+
+ node = of_get_next_parent(node);
+ }
+ of_node_put(node);
+
+ return p_bus_freq ? *p_bus_freq : 0;
+}
+EXPORT_SYMBOL(mpc5xxx_get_bus_frequency);