drivers/video/fbdev/core/fb_notify.c

   1 /*
   2  *  linux/drivers/video/fb_notify.c
   3  *
   4  *  Copyright (C) 2006 Antonino Daplas <adaplas@pol.net>
   5  *
   6  *      2001 - Documented with DocBook
   7  *      - Brad Douglas <brad@neruo.com>
   8  *
   9  * This file is subject to the terms and conditions of the GNU General Public
  10  * License.  See the file COPYING in the main directory of this archive
  11  * for more details.
  12  */
  13 #include <linux/fb.h>
  14 #include <linux/notifier.h>
  15 #include <linux/export.h>
  16
  17 static BLOCKING_NOTIFIER_HEAD(fb_notifier_list);
  18
  19 /**
  20  *      fb_register_client - register a client notifier
  21  *      @nb: notifier block to callback on events
  22  *
  23  *      Return: 0 on success, negative error code on failure.
  24  */
  25 int fb_register_client(struct notifier_block *nb)
  26 {
  27         return blocking_notifier_chain_register(&fb_notifier_list, nb);
  28 }
  29 EXPORT_SYMBOL(fb_register_client);
  30
  31 /**
  32  *      fb_unregister_client - unregister a client notifier
  33  *      @nb: notifier block to callback on events
  34  *
  35  *      Return: 0 on success, negative error code on failure.
  36  */
  37 int fb_unregister_client(struct notifier_block *nb)
  38 {
  39         return blocking_notifier_chain_unregister(&fb_notifier_list, nb);
  40 }
  41 EXPORT_SYMBOL(fb_unregister_client);
  42
  43 /**
  44  * fb_notifier_call_chain - notify clients of fb_events
  45  * @val: value passed to callback
  46  * @v: pointer passed to callback
  47  *
  48  * Return: The return value of the last notifier function
  49  */
  50 int fb_notifier_call_chain(unsigned long val, void *v)
  51 {
  52         return blocking_notifier_call_chain(&fb_notifier_list, val, v);
  53 }
  54 EXPORT_SYMBOL_GPL(fb_notifier_call_chain);