mbed-os/targets/TARGET_ARM_SSG/TARGET_CM3DS_MPS2/lp_ticker.c

114 lines
2.7 KiB
C

/* mbed Microcontroller Library
* Copyright (c) 2018 ARM Limited
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* Low-power elapsed time measure and interval timer in micro-secundum,
* servicing \ref lp_ticker_api.h, using CMSDK Timer1 \ref CMSDK_TIMER1_DEV.
*/
#include <limits.h>
#include "cmsdk_ticker.h"
#include "lp_ticker_api.h"
#include "platform_devices.h"
/**
* \brief Calculate clocks to us
*
* \param[in] tick Number of clock ticks
*
* \return Number of usec, relative to the timer frequency,
* that a given ammount of ticks equates to.
*/
static uint32_t convert_tick_to_us(uint32_t tick)
{
return (tick / (SystemCoreClock / SEC_TO_USEC_MULTIPLIER));
}
/**
* \brief Calculate us to clock ticks
*
* \param[in] us Time to convert to clock ticks
*
* \return Number of clock ticks relative to the timer frequency,
* that a given period of usec equates to.
*/
static uint32_t convert_us_to_tick(uint32_t us)
{
return (us * (SystemCoreClock / SEC_TO_USEC_MULTIPLIER));
}
static const struct tick_cfg_t cfg =
{
.timer_driver = &CMSDK_TIMER1_DEV,
.irq_n = TIMER1_IRQn,
.interval_callback = &lp_ticker_irq_handler,
.convert_tick_to_time = &convert_tick_to_us,
.convert_time_to_tick = &convert_us_to_tick
};
static struct tick_data_t data =
{
.is_initialized = false,
.cumulated_time = 0,
.max_interval_time = 0,
.reload_time = 0,
.interval_callback_enabled = false,
.previous_cumulated_time = 0,
.previous_elapsed = 0
};
static struct tick_drv_data_t timer_data =
{
.cfg = &cfg,
.data = &data
};
void lp_ticker_init(void)
{
cmsdk_ticker_init(&timer_data);
}
uint32_t lp_ticker_read()
{
return cmsdk_ticker_read(&timer_data);
}
void lp_ticker_set_interrupt(timestamp_t timestamp)
{
cmsdk_ticker_set_interrupt(&timer_data, timestamp);
}
void lp_ticker_disable_interrupt(void)
{
cmsdk_ticker_disable_interrupt(&timer_data);
}
void lp_ticker_clear_interrupt(void)
{
cmsdk_ticker_clear_interrupt(&timer_data);
}
void lp_ticker_fire_interrupt(void)
{
cmsdk_ticker_fire_interrupt(&timer_data);
}
void TIMER1_IRQHandler(void)
{
cmsdk_ticker_irq_handler(&timer_data);
}