target/linux/s3c24xx/patches-2.6.26/1154-introduce-resume-dependency.patch.patch

   1 From 8330651863c4b554961204475073b7af1cdf10bc Mon Sep 17 00:00:00 2001
   2 From: Andy Green <andy@openmoko.com>
   3 Date: Fri, 25 Jul 2008 23:06:11 +0100
   4 Subject: [PATCH] introduce-resume-dependency.patch
   5
   6 Defines a way for drivers to defer execution of resume callbacks
   7 until one or more other driver they are dependent on has itself
   8 resumed.
   9
  10 Signed-off-by: Andy Green <andy@openmoko.com>
  11 ---
  12  include/linux/resume-dependency.h |   78 +++++++++++++++++++++++++++++++++++++
  13  1 files changed, 78 insertions(+), 0 deletions(-)
  14  create mode 100644 include/linux/resume-dependency.h
  15
  16 diff --git a/include/linux/resume-dependency.h b/include/linux/resume-dependency.h
  17 new file mode 100644
  18 index 0000000..b13aa3e
  19 --- /dev/null
  20 +++ b/include/linux/resume-dependency.h
  21 @@ -0,0 +1,78 @@
  22 +#ifndef __RESUME_DEPENDENCY_H__
  23 +#define __RESUME_DEPENDENCY_H__
  24 +
  25 +/* Resume dependency framework
  26 + *
  27 + * (C) 2008 Openmoko, Inc.
  28 + * Author: Andy Green <andy@openmoko.com>
  29 + *
  30 + * This program is free software; you can redistribute it and/or
  31 + * modify it under the terms of the GNU General Public License as
  32 + * published by the Free Software Foundation; version 2.1.
  33 + *
  34 + * This program is distributed in the hope that it will be useful,
  35 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
  36 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  37 + * GNU General Public License for more details.
  38 + *
  39 + * You should have received a copy of the GNU General Public License
  40 + * along with this program; if not, write to the Free Software
  41 + * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  42 + * MA 02111-1307 USA
  43 + *
  44 + */
  45 +
  46 +#include <linux/list.h>
  47 +
  48 +struct resume_dependency {
  49 +       struct list_head list;
  50 +
  51 +       void (*callback)(void *); /* called with context as arg */
  52 +       void * context;
  53 +       int called_flag; /* set to 1 after called, use for multi dep */
  54 +};
  55 +
  56 +/* if you are a driver accept to have other drivers as dependencies, you need to
  57 + * instantiate a struct resume_dependency above, then initialize it by invoking
  58 + * init_resume_dependency_list() on it
  59 + */
  60 +
  61 +#define init_resume_dependency_list(_head) \
  62 +       INIT_LIST_HEAD(&_head.list);
  63 +
  64 +
  65 +/* if your resume function depends on something else being resumed first, you
  66 + * can register the dependency by calling this in your suspend function with
  67 + * head being the list held by the thing you are dependent on, and dep being
  68 + * your struct resume_dependency
  69 + */
  70 +
  71 +#define register_resume_dependency(_head, _dep) { \
  72 +       _dep->called_flag = 0; \
  73 +       list_add(&_dep->list, &_head->list); \
  74 +}
  75 +
  76 +/* In the resume function that things can be dependent on, at the end you
  77 + * invoke this macro.  This calls back the dependent resumes now it is safe to
  78 + * use the resumed thing they were dependent on.
  79 + */
  80 +
  81 +#define callback_all_resume_dependencies(_head) { \
  82 +       struct list_head *_pos, *_q; \
  83 +       struct resume_dependency *_dep; \
  84 +\
  85 +       list_for_each_safe(pos, _q, &_head.list) { \
  86 +               _dep = list_entry(_pos, struct resume_dependency, list); \
  87 +               _dep->called_flag = 1; \
  88 +               (_dep->callback)(dep->context); \
  89 +               list_del(_pos); \
  90 +       } \
  91 +}
  92 +
  93 +/* if your resume action is dependent on multiple drivers being resumed already,
  94 + * register the same callback with each driver you are dependent on, and check
  95 + * .called_flag for all of the struct resume_dependency.  When they are all 1
  96 + * you know it is the last callback and you can resume, otherwise just return
  97 + */
  98 +
  99 +#endif
 100 --
 101 1.5.6.3
 102