arch/powerpc/sysdev/mpc5xxx_clocks.c

   1 /**
   2  *      mpc5xxx_get_bus_frequency - Find the bus frequency for a device
   3  *      @node:  device node
   4  *
   5  *      Returns bus frequency (IPS on MPC512x, IPB on MPC52xx),
   6  *      or 0 if the bus frequency cannot be found.
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/of_platform.h>
  11 #include <linux/export.h>
  12 #include <asm/mpc5xxx.h>
  13
  14 unsigned long mpc5xxx_get_bus_frequency(struct device_node *node)
  15 {
  16         const unsigned int *p_bus_freq = NULL;
  17
  18         of_node_get(node);
  19         while (node) {
  20                 p_bus_freq = of_get_property(node, "bus-frequency", NULL);
  21                 if (p_bus_freq)
  22                         break;
  23
  24                 node = of_get_next_parent(node);
  25         }
  26         of_node_put(node);
  27
  28         return p_bus_freq ? *p_bus_freq : 0;
  29 }
  30 EXPORT_SYMBOL(mpc5xxx_get_bus_frequency);