events: Import event handling library from omap3-isp-live

The omap3-isp-live project [1] includes a generic event handling library
that implements a select-based loop. Instead of reinventing the wheel,
import the library and use it.

The original license hasn't been modified, and includes both GPL-2.0+
and LGPL-2.1+ code. The sole copyright owner is Laurent Pinchart.

[1] git://git.ideasonboard.org/omap3-isp-live.git

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 95 insertions, 0 deletions

diff --git a/list.h b/list.h
new file mode 100644
index 0000000..8854c6e
--- /dev/null
+++ b/list.h
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Double Linked Lists
+ *
+ * Copyright (C) 2018 Laurent Pinchart
+ *
+ * This file comes from the omap3-isp-live project
+ * (git://git.ideasonboard.org/omap3-isp-live.git)
+ *
+ * Copyright (C) 2010-2011 Ideas on board SPRL
+ *
+ * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ */
+
+#ifndef __LIST_H
+#define __LIST_H
+
+#include <stddef.h>
+
+struct list_entry {
+	struct list_entry *prev;
+	struct list_entry *next;
+};
+
+static inline void list_init(struct list_entry *list)
+{
+	list->next = list;
+	list->prev = list;
+}
+
+static inline int list_empty(struct list_entry *list)
+{
+	return list->next == list;
+}
+
+static inline void list_append(struct list_entry *entry, struct list_entry *list)
+{
+	entry->next = list;
+	entry->prev = list->prev;
+	list->prev->next = entry;
+	list->prev = entry;
+}
+
+static inline void list_prepend(struct list_entry *entry, struct list_entry *list)
+{
+	entry->next = list->next;
+	entry->prev = list;
+	list->next->prev = entry;
+	list->next = entry;
+}
+
+static inline void list_insert_after(struct list_entry *entry, struct list_entry *after)
+{
+	list_prepend(entry, after);
+}
+
+static inline void list_insert_before(struct list_entry *entry, struct list_entry *before)
+{
+	list_append(entry, before);
+}
+
+static inline void list_remove(struct list_entry *entry)
+{
+	entry->prev->next = entry->next;
+	entry->next->prev = entry->prev;
+}
+
+#define list_entry(entry, type, member) \
+	(type *)((char *)(entry) - offsetof(type, member))
+
+#define list_first_entry(list, type, member) \
+	list_entry((list)->next, type, member)
+
+#define list_last_entry(list, type, member) \
+	list_entry((list)->prev, type, member)
+
+#define list_for_each(entry, list) \
+	for (entry = (list)->next; entry != (list); entry = entry->next)
+
+#define list_for_each_entry(entry, list, member) \
+	for (entry = list_entry((list)->next, typeof(*entry), member); \
+	     &entry->member != (list); \
+	     entry = list_entry(entry->member.next, typeof(*entry), member))
+
+#define list_for_each_safe(entry, __next, list) \
+	for (entry = (list)->next, __next = entry->next; entry != (list); \
+	     entry = __next, __next = entry->next)
+
+#define list_for_each_entry_safe(entry, __next, list, member) \
+	for (entry = list_entry((list)->next, typeof(*entry), member), \
+	     __next = list_entry(entry->member.next, typeof(*entry), member); \
+	     &entry->member != (list); \
+	     entry = __next, __next = list_entry(entry->member.next, typeof(*entry), member))
+
+#endif /* __LIST_H */