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-rw-r--r--arch/powerpc/sysdev/mpc5xxx_clocks.c33
1 files changed, 33 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/mpc5xxx_clocks.c b/arch/powerpc/sysdev/mpc5xxx_clocks.c
new file mode 100644
index 000000000000..34e12f9995fe
--- /dev/null
+++ b/arch/powerpc/sysdev/mpc5xxx_clocks.c
@@ -0,0 +1,33 @@
+/**
+ * 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>
+
+unsigned int
+mpc5xxx_get_bus_frequency(struct device_node *node)
+{
+ struct device_node *np;
+ 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;
+
+ np = of_get_parent(node);
+ of_node_put(node);
+ node = np;
+ }
+ if (node)
+ of_node_put(node);
+
+ return p_bus_freq ? *p_bus_freq : 0;
+}
+EXPORT_SYMBOL(mpc5xxx_get_bus_frequency);