lib/notifier.c

   1 #include <common.h>
   2 #include <linux/list.h>
   3 #include <notifier.h>
   4
   5 int notifier_chain_register(struct notifier_head *nh, struct notifier_block *n)
   6 {
   7         list_add_tail(&n->list, &nh->blocks);
   8         return 0;
   9 }
  10
  11 int notifier_chain_unregister(struct notifier_head *nh, struct notifier_block *n)
  12 {
  13         list_del(&n->list);
  14         return 0;
  15 }
  16
  17 int notifier_call_chain(struct notifier_head *nh, unsigned long val, void *v)
  18 {
  19         struct notifier_block *entry;
  20
  21         list_for_each_entry(entry, &nh->blocks, list)
  22                 entry->notifier_call(entry, val, v);
  23
  24         return 0;
  25 }
  26
  27 /*
  28  *      Notifier list for code which wants to be called at clock
  29  *      frequency changes.
  30  */
  31 static NOTIFIER_HEAD(clock_notifier_list);
  32
  33 /**
  34  *      clock_register_client - register a client notifier
  35  *      @nb: notifier block to callback on events
  36  */
  37 int clock_register_client(struct notifier_block *nb)
  38 {
  39         return notifier_chain_register(&clock_notifier_list, nb);
  40 }
  41
  42 /**
  43  *      clock_register_client - unregister a client notifier
  44  *      @nb: notifier block to callback on events
  45  */
  46 int clock_unregister_client(struct notifier_block *nb)
  47 {
  48         return notifier_chain_unregister(&clock_notifier_list, nb);
  49 }
  50
  51 /**
  52  * clock_register_client - notify clients of clock frequency changes
  53  *
  54  */
  55 int clock_notifier_call_chain(void)
  56 {
  57         return notifier_call_chain(&clock_notifier_list, 0, NULL);
  58 }
  59