34e43c7ee9
SysTick IRQ now increases millisecond counter directly (ie without calling HAL_IncTick). Provide our own version of HAL_Delay that does a wfi while waiting. This more than halves power consumption when running a loop containing a pyb.delay call. It used to be like this, but new version of HAL library regressed this feature.
92 lines
3.7 KiB
C
92 lines
3.7 KiB
C
/*
|
|
* This file is part of the Micro Python project, http://micropython.org/
|
|
*
|
|
* The MIT License (MIT)
|
|
*
|
|
* Copyright (c) 2013, 2014 Damien P. George
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#include <stm32f4xx_hal.h>
|
|
#include "mpconfig.h"
|
|
#include "misc.h"
|
|
#include "nlr.h"
|
|
#include "qstr.h"
|
|
#include "obj.h"
|
|
#include "irq.h"
|
|
#include "systick.h"
|
|
|
|
// We provide our own version of HAL_Delay that calls __WFI while waiting, in
|
|
// order to reduce power consumption.
|
|
void HAL_Delay(uint32_t Delay) {
|
|
extern __IO uint32_t uwTick;
|
|
uint32_t start = uwTick;
|
|
// Wraparound of tick is taken care of by 2's complement arithmetic.
|
|
while (uwTick - start < Delay) {
|
|
// Enter sleep mode, waiting for (at least) the SysTick interrupt.
|
|
__WFI();
|
|
}
|
|
}
|
|
|
|
bool sys_tick_has_passed(uint32_t start_tick, uint32_t delay_ms) {
|
|
return HAL_GetTick() - start_tick >= delay_ms;
|
|
}
|
|
|
|
// waits until at least delay_ms milliseconds have passed from the sampling of
|
|
// startTick. Handles overflow properly. Assumes stc was taken from
|
|
// HAL_GetTick() some time before calling this function.
|
|
void sys_tick_wait_at_least(uint32_t start_tick, uint32_t delay_ms) {
|
|
while (!sys_tick_has_passed(start_tick, delay_ms)) {
|
|
__WFI(); // enter sleep mode, waiting for interrupt
|
|
}
|
|
}
|
|
|
|
// The SysTick timer counts down at 168 MHz, so we can use that knowledge
|
|
// to grab a microsecond counter.
|
|
//
|
|
// We assume that HAL_GetTickis returns milliseconds.
|
|
uint32_t sys_tick_get_microseconds(void) {
|
|
mp_uint_t irq_state = disable_irq();
|
|
uint32_t counter = SysTick->VAL;
|
|
uint32_t milliseconds = HAL_GetTick();
|
|
uint32_t status = SysTick->CTRL;
|
|
enable_irq(irq_state);
|
|
|
|
// It's still possible for the countflag bit to get set if the counter was
|
|
// reloaded between reading VAL and reading CTRL. With interrupts disabled
|
|
// it definitely takes less than 50 HCLK cycles between reading VAL and
|
|
// reading CTRL, so the test (counter > 50) is to cover the case where VAL
|
|
// is +ve and very close to zero, and the COUNTFLAG bit is also set.
|
|
if ((status & SysTick_CTRL_COUNTFLAG_Msk) && counter > 50) {
|
|
// This means that the HW reloaded VAL between the time we read VAL and the
|
|
// time we read CTRL, which implies that there is an interrupt pending
|
|
// to increment the tick counter.
|
|
milliseconds++;
|
|
}
|
|
uint32_t load = SysTick->LOAD;
|
|
counter = load - counter; // Convert from decrementing to incrementing
|
|
|
|
// ((load + 1) / 1000) is the number of counts per microsecond.
|
|
//
|
|
// counter / ((load + 1) / 1000) scales from the systick clock to microseconds
|
|
// and is the same thing as (counter * 1000) / (load + 1)
|
|
return milliseconds * 1000 + (counter * 1000) / (load + 1);
|
|
}
|