Contiki 2.6

button.c

00001 /*
00002  * Copyright (c) 2006, Swedish Institute of Computer Science
00003  * All rights reserved. 
00004  *
00005  * Redistribution and use in source and binary forms, with or without 
00006  * modification, are permitted provided that the following conditions 
00007  * are met: 
00008  * 1. Redistributions of source code must retain the above copyright 
00009  *    notice, this list of conditions and the following disclaimer. 
00010  * 2. Redistributions in binary form must reproduce the above copyright 
00011  *    notice, this list of conditions and the following disclaimer in the 
00012  *    documentation and/or other materials provided with the distribution. 
00013  * 3. Neither the name of the Institute nor the names of its contributors 
00014  *    may be used to endorse or promote products derived from this software 
00015  *    without specific prior written permission. 
00016  *
00017  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 
00018  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
00019  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
00020  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 
00021  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
00022  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 
00023  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
00024  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
00025  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 
00026  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
00027  * SUCH DAMAGE. 
00028  *
00029  * @(#)$Id: button.c,v 1.2 2006/08/17 15:41:13 bg- Exp $
00030  */
00031 
00032 #include "contiki.h"
00033 #include "dev/button.h"
00034 #include "isr_compat.h"
00035 
00036 #define BUTTON_PORT 2
00037 #define BUTTON_PIN  7
00038 
00039 static struct button_msg button_msg;
00040 
00041 static struct process *selecting_proc;
00042 
00043 void
00044 button_init(struct process *proc)
00045 {
00046   button_msg.type = BUTTON_MSG_TYPE;
00047 
00048   P2DIR &= ~BV(BUTTON_PIN);
00049   P2SEL &= ~BV(BUTTON_PIN);
00050 
00051   P2IES |= BV(BUTTON_PIN);
00052   P2IFG &= ~BV(BUTTON_PIN);
00053 
00054   selecting_proc = proc;
00055   if(proc != NULL)
00056     P2IE |= BV(BUTTON_PIN);
00057   else
00058     P2IE &= ~BV(BUTTON_PIN);
00059 }
00060 
00061 ISR(PORT2, __button_interrupt)
00062 {
00063   static struct timer debouncetimer;
00064 
00065   P2IFG &= ~BV(BUTTON_PIN);
00066   if(timer_expired(&debouncetimer)) {
00067     button_msg.value = P2IN & BV(BUTTON_PIN);
00068     timer_set(&debouncetimer, CLOCK_SECOND/4);
00069     if(selecting_proc != NULL) {
00070       process_post(selecting_proc, PROCESS_EVENT_MSG, &button_msg);
00071     }
00072     LPM4_EXIT;
00073   }
00074 }