mbed-os/targets/TARGET_STM/lp_ticker.c

325 lines
10 KiB
C

/* mbed Microcontroller Library
*******************************************************************************
* Copyright (c) 2017, STMicroelectronics
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. Neither the name of STMicroelectronics nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*******************************************************************************
*/
#if DEVICE_LOWPOWERTIMER
#include "rtc_api_hal.h"
#if MBED_CONF_TARGET_LOWPOWERTIMER_LPTIM
LPTIM_HandleTypeDef LptimHandle;
volatile uint32_t lp_SlaveCounter = 0;
volatile uint32_t lp_oc_int_part = 0;
volatile uint16_t lp_TickPeriod_us;
volatile uint8_t lp_Fired = 0;
static void LPTIM1_IRQHandler(void);
static void (*irq_handler)(void);
void lp_ticker_init(void)
{
/* Check if LPTIM is already configured */
#if (TARGET_STM32L0)
if (READ_BIT(RCC->APB1ENR, RCC_APB1ENR_LPTIM1EN) != RESET) {
return;
}
#else
if (__HAL_RCC_LPTIM1_IS_CLK_ENABLED()) {
return;
}
#endif
RCC_PeriphCLKInitTypeDef RCC_PeriphCLKInitStruct = {0};
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
#if MBED_CONF_TARGET_LSE_AVAILABLE
/* Enable LSE clock */
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSE;
RCC_OscInitStruct.LSEState = RCC_LSE_ON;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
/* Select the LSE clock as LPTIM peripheral clock */
RCC_PeriphCLKInitStruct.PeriphClockSelection = RCC_PERIPHCLK_LPTIM1;
#if (TARGET_STM32L0)
RCC_PeriphCLKInitStruct.LptimClockSelection = RCC_LPTIM1CLKSOURCE_LSE;
#else
RCC_PeriphCLKInitStruct.Lptim1ClockSelection = RCC_LPTIM1CLKSOURCE_LSE;
#endif
#else /* MBED_CONF_TARGET_LSE_AVAILABLE */
/* Enable LSI clock */
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSI;
RCC_OscInitStruct.LSIState = RCC_LSI_ON;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
/* Select the LSI clock as LPTIM peripheral clock */
RCC_PeriphCLKInitStruct.PeriphClockSelection = RCC_PERIPHCLK_LPTIM1;
#if (TARGET_STM32L0)
RCC_PeriphCLKInitStruct.LptimClockSelection = RCC_LPTIM1CLKSOURCE_LSI;
#else
RCC_PeriphCLKInitStruct.Lptim1ClockSelection = RCC_LPTIM1CLKSOURCE_LSI;
#endif
#endif /* MBED_CONF_TARGET_LSE_AVAILABLE */
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
error("HAL_RCC_OscConfig ERROR\n");
return;
}
if (HAL_RCCEx_PeriphCLKConfig(&RCC_PeriphCLKInitStruct) != HAL_OK) {
error("HAL_RCCEx_PeriphCLKConfig ERROR\n");
return;
}
__HAL_RCC_LPTIM1_CLK_ENABLE();
__HAL_RCC_LPTIM1_FORCE_RESET();
__HAL_RCC_LPTIM1_RELEASE_RESET();
/* Initialize the LPTIM peripheral */
LptimHandle.Instance = LPTIM1;
LptimHandle.State = HAL_LPTIM_STATE_RESET;
LptimHandle.Init.Clock.Source = LPTIM_CLOCKSOURCE_APBCLOCK_LPOSC;
/* Prescaler impact:
tick period = Prescaler division factor / LPTIM clock
Example with LPTIM clock = 32768 Hz LSE
Prescaler = LPTIM_PRESCALER_DIV1 => lp_TickPeriod_us = 31us => 2s with 16b timer
Prescaler = LPTIM_PRESCALER_DIV2 => lp_TickPeriod_us = 61us => 4s with 16b timer
Prescaler = LPTIM_PRESCALER_DIV4 => lp_TickPeriod_us = 122us => 8s with 16b timer
Prescaler = LPTIM_PRESCALER_DIV8 => lp_TickPeriod_us = 244us => 16s with 16b timer
Prescaler = LPTIM_PRESCALER_DIV16 => lp_TickPeriod_us = 488us => 32s with 16b timer
Prescaler = LPTIM_PRESCALER_DIV32 => lp_TickPeriod_us = 976us => 64s with 16b timer
Prescaler = LPTIM_PRESCALER_DIV64 => lp_TickPeriod_us = 1.9ms => 128s with 16b timer
Prescaler = LPTIM_PRESCALER_DIV128 => lp_TickPeriod_us = 3.9ms => 256s with 16b timer
*/
LptimHandle.Init.Clock.Prescaler = LPTIM_PRESCALER_DIV2;
lp_TickPeriod_us = 2 * 1000000 / RTC_CLOCK;
LptimHandle.Init.Trigger.Source = LPTIM_TRIGSOURCE_SOFTWARE;
LptimHandle.Init.OutputPolarity = LPTIM_OUTPUTPOLARITY_HIGH;
LptimHandle.Init.UpdateMode = LPTIM_UPDATE_IMMEDIATE;
LptimHandle.Init.CounterSource = LPTIM_COUNTERSOURCE_INTERNAL;
#if (TARGET_STM32L4)
LptimHandle.Init.Input1Source = LPTIM_INPUT1SOURCE_GPIO;
LptimHandle.Init.Input2Source = LPTIM_INPUT2SOURCE_GPIO;
#endif /* TARGET_STM32L4 */
if (HAL_LPTIM_Init(&LptimHandle) != HAL_OK) {
error("HAL_LPTIM_Init ERROR\n");
return;
}
NVIC_SetVector(LPTIM1_IRQn, (uint32_t)LPTIM1_IRQHandler);
NVIC_EnableIRQ(LPTIM1_IRQn);
#if !(TARGET_STM32L4)
/* EXTI lines are not configured by default */
__HAL_LPTIM_WAKEUPTIMER_EXTI_ENABLE_IT();
__HAL_LPTIM_WAKEUPTIMER_EXTI_ENABLE_RISING_EDGE();
#endif
__HAL_LPTIM_ENABLE_IT(&LptimHandle, LPTIM_IT_ARRM);
__HAL_LPTIM_ENABLE_IT(&LptimHandle, LPTIM_IT_CMPM);
__HAL_LPTIM_ENABLE_IT(&LptimHandle, LPTIM_IT_CMPOK);
HAL_LPTIM_Counter_Start(&LptimHandle, 0xFFFF);
}
static void LPTIM1_IRQHandler(void)
{
LptimHandle.Instance = LPTIM1;
if (lp_Fired) {
lp_Fired = 0;
if (irq_handler) {
irq_handler();
}
}
/* Compare match interrupt */
if (__HAL_LPTIM_GET_FLAG(&LptimHandle, LPTIM_FLAG_CMPM) != RESET) {
if (__HAL_LPTIM_GET_IT_SOURCE(&LptimHandle, LPTIM_IT_CMPM) != RESET) {
/* Clear Compare match flag */
__HAL_LPTIM_CLEAR_FLAG(&LptimHandle, LPTIM_FLAG_CMPM);
if (lp_oc_int_part > 0) {
lp_oc_int_part--;
} else {
if (irq_handler) {
irq_handler();
}
}
}
}
/* Compare write interrupt */
if (__HAL_LPTIM_GET_FLAG(&LptimHandle, LPTIM_FLAG_CMPOK) != RESET) {
if (__HAL_LPTIM_GET_IT_SOURCE(&LptimHandle, LPTIM_IT_CMPOK) != RESET) {
/* Clear Compare write flag */
__HAL_LPTIM_CLEAR_FLAG(&LptimHandle, LPTIM_FLAG_CMPOK);
}
}
/* Autoreload match interrupt */
if (__HAL_LPTIM_GET_FLAG(&LptimHandle, LPTIM_FLAG_ARRM) != RESET) {
if (__HAL_LPTIM_GET_IT_SOURCE(&LptimHandle, LPTIM_IT_ARRM) != RESET) {
/* Clear Autoreload match flag */
__HAL_LPTIM_CLEAR_FLAG(&LptimHandle, LPTIM_FLAG_ARRM);
lp_SlaveCounter++;
}
}
#if !(TARGET_STM32L4)
__HAL_LPTIM_WAKEUPTIMER_EXTI_CLEAR_FLAG();
#endif
}
uint32_t lp_ticker_read_TickCounter(void)
{
uint16_t cntH_old, cntH, cntL;
LptimHandle.Instance = LPTIM1;
/* same algo as us_ticker_read in us_ticker_16b.c */
do {
cntH_old = lp_SlaveCounter;
if (__HAL_LPTIM_GET_FLAG(&LptimHandle, LPTIM_FLAG_ARRM) == SET) {
cntH_old += 1;
}
cntL = LPTIM1->CNT;
cntH = lp_SlaveCounter;
if (__HAL_LPTIM_GET_FLAG(&LptimHandle, LPTIM_FLAG_ARRM) == SET) {
cntH += 1;
}
} while (cntH_old != cntH);
uint32_t lp_time = (uint32_t)(cntH << 16 | cntL);
return lp_time;
}
uint32_t lp_ticker_read(void)
{
lp_ticker_init();
return lp_ticker_read_TickCounter() * (uint32_t)lp_TickPeriod_us;
}
void lp_ticker_set_interrupt(timestamp_t timestamp)
{
// Disable IRQs
core_util_critical_section_enter();
uint32_t timestamp_TickCounter = timestamp / (uint32_t)lp_TickPeriod_us;
LptimHandle.Instance = LPTIM1;
irq_handler = (void (*)(void))lp_ticker_irq_handler;
__HAL_LPTIM_CLEAR_FLAG(&LptimHandle, LPTIM_FLAG_CMPOK);
__HAL_LPTIM_CLEAR_FLAG(&LptimHandle, LPTIM_FLAG_CMPM);
__HAL_LPTIM_COMPARE_SET(&LptimHandle, timestamp_TickCounter & 0xFFFF);
/* CMPOK is set by hardware to inform application that the APB bus write operation to the LPTIM_CMP register has been successfully completed */
while (__HAL_LPTIM_GET_FLAG(&LptimHandle, LPTIM_FLAG_CMPOK) == RESET) {
}
/* same algo as us_ticker_set_interrupt in us_ticker_16b.c */
uint32_t current_time_TickCounter = lp_ticker_read_TickCounter();
uint32_t delta = timestamp_TickCounter - current_time_TickCounter;
lp_oc_int_part = (delta - 1) >> 16;
if ( ((delta - 1) & 0xFFFF) >= 0x8000 &&
__HAL_LPTIM_GET_FLAG(&LptimHandle, LPTIM_FLAG_CMPM) == SET ) {
++lp_oc_int_part;
}
// Enable IRQs
core_util_critical_section_exit();
}
void lp_ticker_fire_interrupt(void)
{
lp_Fired = 1;
NVIC_SetPendingIRQ(LPTIM1_IRQn);
}
void lp_ticker_disable_interrupt(void)
{
LptimHandle.Instance = LPTIM1;
__HAL_LPTIM_DISABLE_IT(&LptimHandle, LPTIM_IT_CMPM);
}
void lp_ticker_clear_interrupt(void)
{
LptimHandle.Instance = LPTIM1;
__HAL_LPTIM_CLEAR_FLAG(&LptimHandle, LPTIM_FLAG_CMPM);
}
#else /* MBED_CONF_TARGET_LOWPOWERTIMER_LPTIM */
void lp_ticker_init(void)
{
rtc_init();
}
uint32_t lp_ticker_read(void)
{
uint32_t usecs = rtc_read_us();
return usecs;
}
void lp_ticker_set_interrupt(timestamp_t timestamp)
{
uint32_t delta;
delta = timestamp - lp_ticker_read();
rtc_set_wake_up_timer(delta);
}
void lp_ticker_fire_interrupt(void)
{
NVIC_SetPendingIRQ(RTC_WKUP_IRQn);
}
void lp_ticker_disable_interrupt(void)
{
rtc_deactivate_wake_up_timer();
}
void lp_ticker_clear_interrupt(void)
{
NVIC_ClearPendingIRQ(RTC_WKUP_IRQn);
}
#endif /* MBED_CONF_TARGET_LOWPOWERTIMER_LPTIM */
#endif /* DEVICE_LOWPOWERTIMER */