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

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/*
* 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 "py/gc.h"
#include "py/runtime.h"
#include "shared-bindings/pulseio/PulseOut.h"
#include "shared-bindings/pulseio/PWMOut.h"
#include "supervisor/shared/translate.h"
#include STM32_HAL_H
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#include "common-hal/microcontroller/Pin.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 t7_handle;
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),
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pin_mask(pulseout->pwmout->tim->pin->number), 0);
}
STATIC void start_timer(void) {
// Set the new period
t7_handle.Init.Period = pulse_array[pulse_array_index] - 1;
HAL_TIM_Base_Init(&t7_handle);
// TIM7 has limited HAL support, set registers manually
t7_handle.Instance->SR = 0; // Prevent the SR from triggering an interrupt
t7_handle.Instance->CR1 |= TIM_CR1_CEN; // Resume timer
t7_handle.Instance->CR1 |= TIM_CR1_URS; // Disable non-overflow interrupts
__HAL_TIM_ENABLE_IT(&t7_handle, TIM_IT_UPDATE);
}
STATIC void pulseout_event_handler(void) {
if (curr_pulseout->pwmout == NULL) {
return; //invalid interrupt
}
HAL_GPIO_WritePin(pin_port(2),pin_mask(6), 1);
HAL_GPIO_WritePin(pin_port(2),pin_mask(6), 0);
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() {
#if HAS_BASIC_TIM
__HAL_RCC_TIM7_CLK_DISABLE();
refcount = 0;
#endif
}
void common_hal_pulseio_pulseout_construct(pulseio_pulseout_obj_t* self,
const pulseio_pwmout_obj_t* carrier) {
#if !(HAS_BASIC_TIM)
mp_raise_NotImplementedError(translate("PulseOut not supported on this chip"));
#else
// Add to active PulseOuts
refcount++;
// Calculate a 1 ms period
uint32_t source, clk_div;
source = HAL_RCC_GetPCLK1Freq(); // TIM7 is on APB1
clk_div = RCC->CFGR & RCC_CFGR_PPRE1;
// APB quirk, see See DM00031020 Rev 4, page 115.
if (clk_div != 0) {
// APB prescaler for this timer is > 1
source *= 2;
}
uint32_t prescaler = source/1000000; //1us intervals
__HAL_RCC_TIM7_CLK_ENABLE();
HAL_NVIC_SetPriority(TIM7_IRQn, 4, 0);
HAL_NVIC_EnableIRQ(TIM7_IRQn);
// Timers 6 and 7 have no pins, so using them doesn't affect PWM availability
t7_handle.Instance = TIM7;
t7_handle.Init.Period = 100; //immediately replaced.
t7_handle.Init.Prescaler = prescaler - 1;
t7_handle.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
t7_handle.Init.CounterMode = TIM_COUNTERMODE_UP;
t7_handle.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
HAL_TIM_Base_Init(&t7_handle);
t7_handle.Instance->SR = 0;
// The HAL can't work with const, recast required.
self->pwmout = (pulseio_pwmout_obj_t*)carrier;
turn_off(self);
#endif
}
bool common_hal_pulseio_pulseout_deinited(pulseio_pulseout_obj_t* self) {
return self->pwmout == NULL;
}
void common_hal_pulseio_pulseout_deinit(pulseio_pulseout_obj_t* self) {
if (common_hal_pulseio_pulseout_deinited(self)) {
return;
}
turn_on(self);
self->pwmout = NULL;
refcount--;
if (refcount == 0) {
#if HAS_BASIC_TIM
__HAL_RCC_TIM7_CLK_DISABLE();
#endif
}
}
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(translate("Error: Send Timeout"));
// }
}
//turn off timer counter.
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t7_handle.Instance->CR1 &= ~TIM_CR1_CEN;
}
void TIM7_IRQHandler(void)
{
// Detect TIM Update event
if (__HAL_TIM_GET_FLAG(&t7_handle, TIM_FLAG_UPDATE) != RESET)
{
if (__HAL_TIM_GET_IT_SOURCE(&t7_handle, TIM_IT_UPDATE) != RESET)
{
__HAL_TIM_CLEAR_IT(&t7_handle, TIM_IT_UPDATE);
pulseout_event_handler();
}
}
}