xref: /linux/arch/powerpc/sysdev/mpc5xxx_clocks.c (revision 1a2ac6d7ecdcde74a4e16f31de64124160fc7237)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include <linux/kernel.h>
4 #include <linux/export.h>
5 #include <linux/property.h>
6 
7 #include <asm/mpc5xxx.h>
8 
9 /**
10  * mpc5xxx_fwnode_get_bus_frequency - Find the bus frequency for a firmware node
11  * @fwnode:	firmware node
12  *
13  * Returns bus frequency (IPS on MPC512x, IPB on MPC52xx),
14  * or 0 if the bus frequency cannot be found.
15  */
16 unsigned long mpc5xxx_fwnode_get_bus_frequency(struct fwnode_handle *fwnode)
17 {
18 	struct fwnode_handle *parent;
19 	u32 bus_freq;
20 	int ret;
21 
22 	ret = fwnode_property_read_u32(fwnode, "bus-frequency", &bus_freq);
23 	if (!ret)
24 		return bus_freq;
25 
26 	fwnode_for_each_parent_node(fwnode, parent) {
27 		ret = fwnode_property_read_u32(parent, "bus-frequency", &bus_freq);
28 		if (!ret)
29 			return bus_freq;
30 	}
31 
32 	return 0;
33 }
34 EXPORT_SYMBOL(mpc5xxx_fwnode_get_bus_frequency);
35