--- /dev/null
+/*
+ * Copyright © 2013 Keith Packard <keithp@keithp.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 of the License.
+ *
+ * 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.
+ */
+
+#ifndef _AO_DEBOUNCE_H_
+#define _AO_DEBOUNCE_H_
+
+struct ao_debounce {
+ struct ao_debounce *next;
+
+ /* time that pin value must be stable before accepting */
+ int8_t hold;
+
+ /* last value reported to app; don't report it twice */
+ uint8_t value;
+
+ /* current count of intervals pin value has been stable */
+ int8_t count;
+
+ /* This pin is running */
+ uint8_t running;
+
+ /* Get the current pin value */
+ uint8_t (*_get)(struct ao_debounce *debounce);
+
+ /* The stable value has changed */
+ void (*_set)(struct ao_debounce *debounce, uint8_t value);
+};
+
+void
+_ao_debounce_start(struct ao_debounce *debounce);
+
+void
+_ao_debounce_stop(struct ao_debounce *debounce);
+
+void
+ao_debounce_init(void);
+
+#endif /* _AO_DEBOUNCE_H_ */