Contiki 2.6

sensors.c

00001 /*
00002  * Copyright (c) 2009, 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  * This file is part of the Contiki operating system.
00030  *
00031  * @(#)$Id: sensors.c,v 1.5 2010/01/14 20:04:38 nifi Exp $
00032  */
00033 /* exeperimental code, will be renamed to sensors.c when done */
00034 
00035 
00036 #include <string.h>
00037 
00038 #include "contiki.h"
00039 
00040 #include "lib/sensors.h"
00041 
00042 const extern struct sensors_sensor *sensors[];
00043 extern unsigned char sensors_flags[];
00044 
00045 #define FLAG_CHANGED    0x80
00046 
00047 process_event_t sensors_event;
00048 
00049 static unsigned char num_sensors;
00050 
00051 PROCESS(sensors_process, "Sensors");
00052 
00053 /*---------------------------------------------------------------------------*/
00054 static int
00055 get_sensor_index(const struct sensors_sensor *s)
00056 {
00057   int i;
00058   for(i = 0; i < num_sensors; ++i) {
00059     if(sensors[i] == s) {
00060       return i;
00061     }
00062   }
00063   return i;
00064 }
00065 /*---------------------------------------------------------------------------*/
00066 const struct sensors_sensor *
00067 sensors_first(void)
00068 {
00069   return sensors[0];
00070 }
00071 /*---------------------------------------------------------------------------*/
00072 const struct sensors_sensor *
00073 sensors_next(const struct sensors_sensor *s)
00074 {
00075   return sensors[get_sensor_index(s) + 1];
00076 }
00077 /*---------------------------------------------------------------------------*/
00078 void
00079 sensors_changed(const struct sensors_sensor *s)
00080 {
00081   sensors_flags[get_sensor_index(s)] |= FLAG_CHANGED;
00082   process_poll(&sensors_process);
00083 }
00084 /*---------------------------------------------------------------------------*/
00085 const struct sensors_sensor *
00086 sensors_find(const char *prefix)
00087 {
00088   int i;
00089   unsigned short len;
00090 
00091   /* Search through all processes and search for the specified process
00092      name. */
00093   len = strlen(prefix);
00094 
00095   for(i = 0; i < num_sensors; ++i) {
00096     if(strncmp(prefix, sensors[i]->type, len) == 0) {
00097       return sensors[i];
00098     }
00099   }
00100   return NULL;
00101 }
00102 /*---------------------------------------------------------------------------*/
00103 PROCESS_THREAD(sensors_process, ev, data)
00104 {
00105   static int i;
00106   static int events;
00107 
00108   PROCESS_BEGIN();
00109 
00110   sensors_event = process_alloc_event();
00111 
00112   for(i = 0; sensors[i] != NULL; ++i) {
00113     sensors_flags[i] = 0;
00114     sensors[i]->configure(SENSORS_HW_INIT, 0);
00115   }
00116   num_sensors = i;
00117 
00118   while(1) {
00119 
00120     PROCESS_WAIT_EVENT();
00121 
00122     do {
00123       events = 0;
00124       for(i = 0; i < num_sensors; ++i) {
00125         if(sensors_flags[i] & FLAG_CHANGED) {
00126           if(process_post(PROCESS_BROADCAST, sensors_event, (void *)sensors[i]) == PROCESS_ERR_OK) {
00127             PROCESS_WAIT_EVENT_UNTIL(ev == sensors_event);
00128           }
00129           sensors_flags[i] &= ~FLAG_CHANGED;
00130           events++;
00131         }
00132       }
00133     } while(events);
00134   }
00135 
00136   PROCESS_END();
00137 }
00138 /*---------------------------------------------------------------------------*/