stm32: Add PulseOut support

Matches the implementations of the NRF and Atmel ports. TIM7 is used as it does not have a tied pin. Contains some register micromanagement since HAL support for the TIM7 timer is limited.
crypto-aes
Lucian Copeland 3 years ago
parent 1b33cd11fc
commit 611ef27ac2
  1. 2
      ports/stm32f4/common-hal/pulseio/PWMOut.c
  2. 155
      ports/stm32f4/common-hal/pulseio/PulseOut.c
  3. 2
      ports/stm32f4/common-hal/pulseio/PulseOut.h
  4. 2
      ports/stm32f4/supervisor/port.c

@ -163,7 +163,7 @@ pwmout_result_t common_hal_pulseio_pwmout_construct(pulseio_pwmout_obj_t* self,
} else if (var_freq_mismatch) {
mp_raise_ValueError(translate("Cannot vary frequency on a timer that is already in use"));
} else {
mp_raise_ValueError(translate("Invalid pins"));
mp_raise_ValueError(translate("Invalid pins for PWMOut"));
}
}

@ -35,21 +35,172 @@
#include "shared-bindings/pulseio/PWMOut.h"
#include "supervisor/shared/translate.h"
#include "stm32f4xx_hal.h"
#include "common-hal/microcontroller/Pin.h"
#include "tick.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),
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() {
__HAL_RCC_TIM7_CLK_DISABLE();
refcount = 0;
}
void common_hal_pulseio_pulseout_construct(pulseio_pulseout_obj_t* self,
const pulseio_pwmout_obj_t* carrier) {
mp_raise_NotImplementedError(translate("PulseOut not yet supported"));
// 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);
}
bool common_hal_pulseio_pulseout_deinited(pulseio_pulseout_obj_t* self) {
return true;
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) {
__HAL_RCC_TIM7_CLK_DISABLE();
}
}
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.
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();
}
}
}

@ -34,7 +34,7 @@
typedef struct {
mp_obj_base_t base;
const pulseio_pwmout_obj_t *pwmout;
pulseio_pwmout_obj_t *pwmout;
} pulseio_pulseout_obj_t;
void pulseout_reset(void);

@ -35,6 +35,7 @@
#include "common-hal/busio/SPI.h"
#include "common-hal/busio/UART.h"
#include "common-hal/pulseio/PWMOut.h"
#include "common-hal/pulseio/PulseOut.h"
#include "stm32f4/clocks.h"
#include "stm32f4/gpio.h"
@ -60,6 +61,7 @@ void reset_port(void) {
spi_reset();
uart_reset();
pwmout_reset();
pulseout_reset();
}
void reset_to_bootloader(void) {

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