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/*
* Copyright (C) 2014 Freie Universität Berlin
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @ingroup driver_pir
* @{
*
* @file
* @brief Device driver implementation for the PIR motion sensor
*
* @author Ludwig Knüpfer <ludwig.knuepfer@fu-berlin.de>
*
* @}
*/
#include "pir.h"
#include "thread.h"
#include "msg.h"
#define ENABLE_DEBUG (0)
#include "debug.h"
/**********************************************************************
* internal API declaration
**********************************************************************/
static int pir_activate_int(pir_t *dev);
static void pir_callback(void *dev);
static void pir_send_msg(pir_t *dev, pir_event_t event);
/**********************************************************************
* public API implementation
**********************************************************************/
int pir_init(pir_t *dev, gpio_t gpio)
{
dev->gpio_dev = gpio;
dev->msg_thread_pid = KERNEL_PID_UNDEF;
return gpio_init(dev->gpio_dev, GPIO_DIR_IN, GPIO_NOPULL);
}
pir_event_t pir_get_status(pir_t *dev)
{
return ((gpio_read(dev->gpio_dev) == 0) ? PIR_STATUS_LO : PIR_STATUS_HI);
}
int pir_register_thread(pir_t *dev)
{
if (dev->msg_thread_pid != KERNEL_PID_UNDEF) {
if (dev->msg_thread_pid != thread_getpid()) {
DEBUG("pir_register_thread: already registered to another thread\n");
return -2;
}
}
else {
DEBUG("pir_register_thread: activating interrupt for %p..\n", dev);
if (pir_activate_int(dev) != 0) {
DEBUG("\tfailed\n");
return -1;
}
DEBUG("\tsuccess\n");
}
dev->msg_thread_pid = thread_getpid();
return 0;
}
/**********************************************************************
* internal API implementation
**********************************************************************/
static void pir_send_msg(pir_t *dev, pir_event_t event)
{
DEBUG("pir_send_msg\n");
msg_t m = { .type = event, .content.ptr = (char*) dev, };
int ret = msg_send_int(&m, dev->msg_thread_pid);
DEBUG("pir_send_msg: msg_send_int: %i\n", ret);
switch (ret) {
case 0:
DEBUG("pir_send_msg: msg_thread_pid not receptive, event is lost");
break;
case 1:
DEBUG("pir_send_msg: OK");
break;
case -1:
DEBUG("pir_send_msg: msg_thread_pid is gone, clearing it");
dev->msg_thread_pid = KERNEL_PID_UNDEF;
break;
}
}
static void pir_callback(void *arg)
{
DEBUG("pir_callback: %p\n", arg);
pir_t *dev = (pir_t*) arg;
if (dev->msg_thread_pid != KERNEL_PID_UNDEF) {
pir_send_msg(dev, pir_get_status(dev));
}
}
static int pir_activate_int(pir_t *dev)
{
return gpio_init_int(dev->gpio_dev, GPIO_NOPULL, GPIO_BOTH, pir_callback, dev);
}