bacnet_stack/ports/stm32f10x/mstimer-init.c

/**************************************************************************
*
* Copyright (C) 2011 Steve Karg <skarg@users.sourceforge.net>
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* Module Description:
* Generate a periodic timer tick for use by generic timers in the code.
*
*************************************************************************/
#include <stdbool.h>
#include <stdint.h>
#include "hardware.h"
#include "bacnet/basic/sys/mstimer.h"
#include "bacnet/basic/sys/debug.h"

/* counter for the various timers */
static volatile unsigned long Millisecond_Counter;
static volatile struct mstimer_callback_data_t *Callback_Head;

/**
 * Activate the LED
 */
static void timer_debug_on(
    void)
{
    GPIO_WriteBit(GPIOB, GPIO_Pin_13, Bit_SET);
}

/**
 * Deactivate the LED
 */
static void timer_debug_off(
    void)
{
    GPIO_WriteBit(GPIOB, GPIO_Pin_13, Bit_RESET);
}

/**
 * Toggle the state of the debug LED
 */
static void timer_debug_toggle(
    void)
{
    static bool state = false;

    if (state) {
        timer_debug_off();
        state = false;
    } else {
        timer_debug_on();
        state = true;
    }
}

/**
 * Handles the interrupt from the timer
 */
void SysTick_Handler(
    void)
{
    struct mstimer_callback_data_t *cb;

    /* increment the tick count */
    Millisecond_Counter++;
    cb = (struct mstimer_callback_data_t *)Callback_Head;
    while (cb) {
        if (mstimer_expired(&cb->timer)) {
            cb->callback();
            if (mstimer_interval(&cb->timer) > 0) {
                mstimer_reset(&cb->timer);
            }
        }
        cb = cb->next;
    }
    timer_debug_toggle();
}

/**
 * Returns the continuous milliseconds count, which rolls over
 *
 * @return the current milliseconds count
 */
unsigned long mstimer_now(
    void)
{
    return Millisecond_Counter;
}

/**
 * Configures and enables a repeating callback function
 *
 * @param cb - pointer to a #mstimer_callback_data_t
 * @param callback - pointer to a #timer_callback_function function
 * @param milliseconds - how often to call the function
 *
 * @return true if successfully added and enabled
 */
void mstimer_callback(
    struct mstimer_callback_data_t *new_cb,
    mstimer_callback_function callback,
    unsigned long milliseconds)
{
    struct mstimer_callback_data_t *cb;

    if (new_cb) {
        new_cb->callback = callback;
        mstimer_set(&new_cb->timer, milliseconds);
    }
    if (Callback_Head) {
        cb = (struct mstimer_callback_data_t *)Callback_Head;
        while (cb) {
            if (!cb->next) {
                cb->next = new_cb;
                break;
            } else {
                cb = cb->next;
            }
        }
    } else {
        Callback_Head = new_cb;
    }
}

/**
 * Timer setup for 1 millisecond timer
 */
void mstimer_init(
    void)
{
    GPIO_InitTypeDef GPIO_InitStructure;

    GPIO_StructInit(&GPIO_InitStructure);
    /* Configure the Receive LED */
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_Init(GPIOB, &GPIO_InitStructure);

    /* Setup SysTick Timer for 1ms interrupts  */
    if (SysTick_Config(SystemCoreClock / 1000)) {
        /* Capture error */
        while (1);
    }

}