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

134 lines
3.1 KiB
C

/* mbed Microcontroller Library
* Copyright (c) 2017-2018 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.
*/
/**
* Elapsed time measure and interval timer in micro-secundum,
* servicing \ref us_ticker_api.h, using CMSDK Timer0 \ref CMSDK_TIMER0_DEV.
*/
#include "cmsdk_ticker.h"
#include "us_ticker_api.h"
#include "platform_devices.h"
/*
* The CMSDK Ticker counts on 32 bits.
*/
#define CMSDK_TICKER_COUNTER_BITS 32U
/**
* \brief Pass-through function to make the US ticker HAL only work in the tick
* domain. This function is needed by the CMSDK Ticker layer.
*
* \param[in] tick Number of clock ticks
*
* \return The number of ticks given.
*/
static uint32_t convert_tick_to_us(uint32_t tick)
{
/* Work only in the tick domain. */
return tick;
}
/**
* \brief Pass-through function to make the US ticker HAL only work in the tick
* domain. This function is needed by the CMSDK Ticker layer.
*
* \param[in] us Number of us
*
* \return The number of us given.
*/
static uint32_t convert_us_to_tick(uint32_t us)
{
/* Work only in the tick domain. */
return us;
}
static const struct tick_cfg_t cfg =
{
.timer_driver = &CMSDK_TIMER0_DEV,
.irq_n = TIMER0_IRQn,
.interval_callback = &us_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 us_ticker_init(void)
{
cmsdk_ticker_init(&timer_data);
}
uint32_t us_ticker_read()
{
return cmsdk_ticker_read(&timer_data);
}
void us_ticker_set_interrupt(timestamp_t timestamp)
{
cmsdk_ticker_set_interrupt(&timer_data, timestamp);
}
void us_ticker_disable_interrupt(void)
{
cmsdk_ticker_disable_interrupt(&timer_data);
}
void us_ticker_clear_interrupt(void)
{
cmsdk_ticker_clear_interrupt(&timer_data);
}
void us_ticker_fire_interrupt(void)
{
cmsdk_ticker_fire_interrupt(&timer_data);
}
void TIMER0_IRQHandler(void)
{
cmsdk_ticker_irq_handler(&timer_data);
}
const ticker_info_t* us_ticker_get_info(void)
{
static ticker_info_t us_ticker_info = {
.bits = CMSDK_TICKER_COUNTER_BITS
};
/*
* SystemCoreClock is not a constant so it cannot be used to initialize the
* ticker_info_t structure.
*/
us_ticker_info.frequency = SystemCoreClock;
return &us_ticker_info;
}