circuitpython/ports/stm/common-hal/pulseio/PulseOut.c

185 lines
6.3 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2019 Lucian Copeland for Adafruit Industries
*
* 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 "common-hal/pulseio/PulseOut.h"
#include <stdint.h>
#include "py/mpconfig.h"
#include "shared-bindings/pulseio/PulseOut.h"
#include "shared-bindings/pwmio/PWMOut.h"
#include STM32_HAL_H
#include "timers.h"
// A single timer is shared amongst all PulseOut objects under the assumption that
// the code is single threaded.
STATIC uint8_t refcount = 0;
STATIC uint16_t *pulse_array = NULL;
STATIC volatile uint16_t pulse_array_index = 0;
STATIC uint16_t pulse_array_length;
// Timer is shared, must be accessible by interrupt
STATIC TIM_HandleTypeDef tim_handle;
STATIC pulseio_pulseout_obj_t *curr_pulseout = NULL;
STATIC void turn_on(pulseio_pulseout_obj_t *pulseout) {
// Turn on PWM
HAL_TIM_PWM_Start(&(pulseout->pwmout.handle), pulseout->pwmout.channel);
}
STATIC void turn_off(pulseio_pulseout_obj_t *pulseout) {
// Turn off PWM
HAL_TIM_PWM_Stop(&(pulseout->pwmout.handle), pulseout->pwmout.channel);
// Make sure pin is low.
HAL_GPIO_WritePin(pin_port(pulseout->pwmout.tim->pin->port),
pin_mask(pulseout->pwmout.tim->pin->number), 0);
}
STATIC void start_timer(void) {
// Set the new period
tim_handle.Init.Period = pulse_array[pulse_array_index] - 1;
HAL_TIM_Base_Init(&tim_handle);
// TIM7 has limited HAL support, set registers manually
tim_handle.Instance->SR = 0; // Prevent the SR from triggering an interrupt
tim_handle.Instance->CR1 |= TIM_CR1_CEN; // Resume timer
tim_handle.Instance->CR1 |= TIM_CR1_URS; // Disable non-overflow interrupts
__HAL_TIM_ENABLE_IT(&tim_handle, TIM_IT_UPDATE);
}
STATIC void pulseout_event_handler(void) {
// Detect TIM Update event
if (__HAL_TIM_GET_FLAG(&tim_handle, TIM_FLAG_UPDATE) != RESET) {
if (__HAL_TIM_GET_IT_SOURCE(&tim_handle, TIM_IT_UPDATE) != RESET) {
__HAL_TIM_CLEAR_IT(&tim_handle, TIM_IT_UPDATE);
if (common_hal_pulseio_pulseout_deinited(curr_pulseout)) {
return; // invalid interrupt
}
pulse_array_index++;
// No more pulses. Turn off output and don't restart.
if (pulse_array_index >= pulse_array_length) {
turn_off(curr_pulseout);
return;
}
// Alternate on and off, starting with on.
if (pulse_array_index % 2 == 0) {
turn_on(curr_pulseout);
} else {
turn_off(curr_pulseout);
}
// Count up to the next given value.
start_timer();
}
}
}
void pulseout_reset() {
stm_peripherals_timer_free(tim_handle.Instance);
refcount = 0;
}
void common_hal_pulseio_pulseout_construct(pulseio_pulseout_obj_t *self,
const mcu_pin_obj_t *pin, uint32_t frequency, uint16_t duty_cycle) {
pwmout_result_t result = common_hal_pwmio_pwmout_construct(
&self->pwmout, pin, duty_cycle, frequency, false);
// This will raise an exception and not return if needed.
common_hal_pwmio_pwmout_raise_error(result);
// Add to active PulseOuts
refcount++;
TIM_TypeDef *tim_instance = stm_peripherals_find_timer();
stm_peripherals_timer_reserve(tim_instance);
// calculate a 1ms period
uint32_t source = stm_peripherals_timer_get_source_freq(tim_instance);
uint32_t prescaler = source / 1000000; // 1us intervals
stm_peripherals_timer_preinit(tim_instance, 4, pulseout_event_handler);
tim_handle.Instance = tim_instance;
tim_handle.Init.Period = 100; // immediately replaced.
tim_handle.Init.Prescaler = prescaler - 1;
tim_handle.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
tim_handle.Init.CounterMode = TIM_COUNTERMODE_UP;
tim_handle.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
HAL_TIM_Base_Init(&tim_handle);
tim_handle.Instance->SR = 0;
turn_off(self);
}
bool common_hal_pulseio_pulseout_deinited(pulseio_pulseout_obj_t *self) {
return common_hal_pwmio_pwmout_deinited(&self->pwmout);
}
void common_hal_pulseio_pulseout_deinit(pulseio_pulseout_obj_t *self) {
if (common_hal_pulseio_pulseout_deinited(self)) {
return;
}
turn_on(self);
common_hal_pwmio_pwmout_deinit(&self->pwmout);
refcount--;
if (refcount == 0) {
stm_peripherals_timer_free(tim_handle.Instance);
}
}
void common_hal_pulseio_pulseout_send(pulseio_pulseout_obj_t *self, uint16_t *pulses, uint16_t length) {
pulse_array = pulses;
pulse_array_index = 0;
pulse_array_length = length;
curr_pulseout = self;
turn_on(self);
// Count up to the next given value.
start_timer();
// Use when debugging, or issues are irrecoverable
// uint32_t starttime = supervisor_ticks_ms64();
// uint32_t timeout = 10000;
while (pulse_array_index < length) {
// Do other things while we wait. The interrupts will handle sending the
// signal.
RUN_BACKGROUND_TASKS;
// // Use when debugging, or issues are irrecoverable
// if ((supervisor_ticks_ms64() - starttime ) > timeout ) {
// mp_raise_RuntimeError(MP_ERROR_TEXT("Error: Send Timeout"));
// }
}
// turn off timer counter.
tim_handle.Instance->CR1 &= ~TIM_CR1_CEN;
}