1 files changed, 36 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/mpc5xxx_clocks.c b/arch/powerpc/sysdev/mpc5xxx_clocks.c
new file mode 100644
index 0000000000..58cee28e23
--- /dev/null
+++ b/arch/powerpc/sysdev/mpc5xxx_clocks.c
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/property.h>
+
+#include <asm/mpc5xxx.h>
+
+/**
+ * mpc5xxx_fwnode_get_bus_frequency - Find the bus frequency for a firmware node
+ * @fwnode:	firmware node
+ *
+ * Returns bus frequency (IPS on MPC512x, IPB on MPC52xx),
+ * or 0 if the bus frequency cannot be found.
+ */
+unsigned long mpc5xxx_fwnode_get_bus_frequency(struct fwnode_handle *fwnode)
+{
+	struct fwnode_handle *parent;
+	u32 bus_freq;
+	int ret;
+
+	ret = fwnode_property_read_u32(fwnode, "bus-frequency", &bus_freq);
+	if (!ret)
+		return bus_freq;
+
+	fwnode_for_each_parent_node(fwnode, parent) {
+		ret = fwnode_property_read_u32(parent, "bus-frequency", &bus_freq);
+		if (!ret) {
+			fwnode_handle_put(parent);
+			return bus_freq;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(mpc5xxx_fwnode_get_bus_frequency);