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authorAndy Green <andy@openmoko.com>2008-11-19 17:09:46 +0000
committerAndy Green <agreen@pads.home.warmcat.com>2008-11-19 17:09:46 +0000
commit45fcad39f329506d3a18ef289792d1f8bdeb0a98 (patch)
tree792c91e256442a6975afb0d0fba90191d9fab679 /include/linux
parentef22f4a84f59f4dd99a0354b82e14f4e4cecd0cd (diff)
introduce-resume-dependency.patch
Defines a way for drivers to defer execution of resume callbacks until one or more other driver they are dependent on has itself resumed. Signed-off-by: Andy Green <andy@openmoko.com>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/resume-dependency.h78
1 files changed, 78 insertions, 0 deletions
diff --git a/include/linux/resume-dependency.h b/include/linux/resume-dependency.h
new file mode 100644
index 00000000000..b13aa3e2b0e
--- /dev/null
+++ b/include/linux/resume-dependency.h
@@ -0,0 +1,78 @@
+#ifndef __RESUME_DEPENDENCY_H__
+#define __RESUME_DEPENDENCY_H__
+
+/* Resume dependency framework
+ *
+ * (C) 2008 Openmoko, Inc.
+ * Author: Andy Green <andy@openmoko.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; version 2.1.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+
+#include <linux/list.h>
+
+struct resume_dependency {
+ struct list_head list;
+
+ void (*callback)(void *); /* called with context as arg */
+ void * context;
+ int called_flag; /* set to 1 after called, use for multi dep */
+};
+
+/* if you are a driver accept to have other drivers as dependencies, you need to
+ * instantiate a struct resume_dependency above, then initialize it by invoking
+ * init_resume_dependency_list() on it
+ */
+
+#define init_resume_dependency_list(_head) \
+ INIT_LIST_HEAD(&_head.list);
+
+
+/* if your resume function depends on something else being resumed first, you
+ * can register the dependency by calling this in your suspend function with
+ * head being the list held by the thing you are dependent on, and dep being
+ * your struct resume_dependency
+ */
+
+#define register_resume_dependency(_head, _dep) { \
+ _dep->called_flag = 0; \
+ list_add(&_dep->list, &_head->list); \
+}
+
+/* In the resume function that things can be dependent on, at the end you
+ * invoke this macro. This calls back the dependent resumes now it is safe to
+ * use the resumed thing they were dependent on.
+ */
+
+#define callback_all_resume_dependencies(_head) { \
+ struct list_head *_pos, *_q; \
+ struct resume_dependency *_dep; \
+\
+ list_for_each_safe(pos, _q, &_head.list) { \
+ _dep = list_entry(_pos, struct resume_dependency, list); \
+ _dep->called_flag = 1; \
+ (_dep->callback)(dep->context); \
+ list_del(_pos); \
+ } \
+}
+
+/* if your resume action is dependent on multiple drivers being resumed already,
+ * register the same callback with each driver you are dependent on, and check
+ * .called_flag for all of the struct resume_dependency. When they are all 1
+ * you know it is the last callback and you can resume, otherwise just return
+ */
+
+#endif