timer.c

Go to the documentation of this file.

/* 
 * timer.c
 * --------------------------------------
 * Implementation of ARMv7 Generic Timer
 * Responsible: Inkyu Han
 */
#include "timer.h"
#include "generic_timer.h"

#include <config/cfg_platform.h>
#include <k-hypervisor-config.h>

static struct timer_channel _channels[TIMER_NUM_MAX_CHANNELS];

static void _timer_each_callback_channel( timer_channel_t channel, void *param)
{
    int i;
    for( i = 0; i < TIMER_MAX_CHANNEL_CALLBACKS; i++ ) {
        if( _channels[channel].callbacks[i] ) _channels[channel].callbacks[i](param);
    }
}

static int _timer_channel_num_callbacks( timer_channel_t channel )
{
    int i, count = 0;
    for( i = 0; i < TIMER_MAX_CHANNEL_CALLBACKS; i++) {
        if( _channels[channel].callbacks[i] ) count++;
    }
    return count;
}

static void _timer_hw_callback(void *pdata)
{
    generic_timer_disable_int(GENERIC_TIMER_HYP);

    _timer_each_callback_channel(timer_sched, pdata);

    generic_timer_set_tval(GENERIC_TIMER_HYP, _channels[timer_sched].interval_us);
    
    generic_timer_enable_int(GENERIC_TIMER_HYP);
}

hvmm_status_t timer_init(timer_channel_t channel)
{   
    int i;
    for( i = 0; i < TIMER_MAX_CHANNEL_CALLBACKS; i++ ) {
        _channels[channel].callbacks[i] = 0;
    }

    generic_timer_init();
    return HVMM_STATUS_SUCCESS;
}
    
hvmm_status_t timer_start(timer_channel_t channel)
{
    if ( _timer_channel_num_callbacks( channel ) > 0 ) {

        generic_timer_set_callback(GENERIC_TIMER_HYP, &_timer_hw_callback );
    
        generic_timer_set_tval(GENERIC_TIMER_HYP, _channels[channel].interval_us);
    
        generic_timer_enable_irq(GENERIC_TIMER_HYP);

        generic_timer_enable_int(GENERIC_TIMER_HYP);
    }

    return HVMM_STATUS_SUCCESS;
}

hvmm_status_t timer_stop(timer_channel_t channel)
{
    generic_timer_disable_int(GENERIC_TIMER_HYP);
    return HVMM_STATUS_SUCCESS;
}

hvmm_status_t timer_set_interval(timer_channel_t channel, uint32_t interval_us)
{
    _channels[channel].interval_us = timer_t2c(interval_us);
    return HVMM_STATUS_SUCCESS;
}

uint32_t timer_get_interval(timer_channel_t channel)
{
    return _channels[channel].interval_us;
}

hvmm_status_t timer_add_callback(timer_channel_t channel, timer_callback_t callback)
{
    int i;
    hvmm_status_t result = HVMM_STATUS_BUSY;
    for( i = 0; i < TIMER_MAX_CHANNEL_CALLBACKS; i++ ) {
        if( _channels[channel].callbacks[i] == 0 ) {
            _channels[channel].callbacks[i] = callback;
            result = HVMM_STATUS_SUCCESS;
            break;
        }
    }
    return result;
}

hvmm_status_t timer_remove_callback(timer_channel_t channel, timer_callback_t callback)
{
    int i;
    hvmm_status_t result = HVMM_STATUS_NOT_FOUND;
    for( i = 0; i < TIMER_MAX_CHANNEL_CALLBACKS; i++ ) {
        if ( _channels[channel].callbacks[i] == callback ) {
            _channels[channel].callbacks[i] = 0;
            result = HVMM_STATUS_SUCCESS;
            break;
        }
    }
    return result;
}

uint64_t timer_t2c(uint64_t time_us)
{
    return time_us * COUNT_PER_USEC;
}