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circuitpython/ports/stm/common-hal/pulseio/PWMOut.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
* Uses code from Micropython, Copyright (c) 2013-2016 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 <stdint.h>
#include "py/runtime.h"
#include "common-hal/pulseio/PWMOut.h"
#include "shared-bindings/pulseio/PWMOut.h"
#include "supervisor/shared/translate.h"
#include "shared-bindings/microcontroller/__init__.h"
#include "stm32f4xx_hal.h"
#include "common-hal/microcontroller/Pin.h"
#define ALL_CLOCKS 0xFFFF
STATIC uint8_t reserved_tim[TIM_BANK_ARRAY_LEN];
STATIC uint32_t tim_frequencies[TIM_BANK_ARRAY_LEN];
STATIC bool never_reset_tim[TIM_BANK_ARRAY_LEN];
STATIC void tim_clock_enable(uint16_t mask);
STATIC void tim_clock_disable(uint16_t mask);
// Get the frequency (in Hz) of the source clock for the given timer.
// On STM32F405/407/415/417 there are 2 cases for how the clock freq is set.
// If the APB prescaler is 1, then the timer clock is equal to its respective
// APB clock. Otherwise (APB prescaler > 1) the timer clock is twice its
// respective APB clock. See DM00031020 Rev 4, page 115.
STATIC uint32_t timer_get_source_freq(uint32_t tim_id) {
uint32_t source, clk_div;
if (tim_id == 1 || (8 <= tim_id && tim_id <= 11)) {
// TIM{1,8,9,10,11} are on APB2
source = HAL_RCC_GetPCLK2Freq();
clk_div = RCC->CFGR & RCC_CFGR_PPRE2;
} else {
// TIM{2,3,4,5,6,7,12,13,14} are on APB1
source = HAL_RCC_GetPCLK1Freq();
clk_div = RCC->CFGR & RCC_CFGR_PPRE1;
}
if (clk_div != 0) {
// APB prescaler for this timer is > 1
source *= 2;
}
return source;
}
STATIC uint32_t timer_get_internal_duty(uint16_t duty, uint32_t period) {
//duty cycle is duty/0xFFFF fraction x (number of pulses per period)
return (duty*period) / ((1 << 16) - 1);
}
STATIC void timer_get_optimal_divisors(uint32_t*period, uint32_t*prescaler,
uint32_t frequency, uint32_t source_freq) {
//Find the largest possible period supported by this frequency
for (int i = 0; i < (1 << 16); i++) {
*period = source_freq / (i * frequency);
if (*period < (1 << 16) && *period >= 2) {
*prescaler = i;
break;
}
}
if (*prescaler == 0) {
mp_raise_ValueError(translate("Invalid frequency supplied"));
}
}
void pwmout_reset(void) {
uint16_t never_reset_mask = 0x00;
for (int i = 0; i < TIM_BANK_ARRAY_LEN; i++) {
if (!never_reset_tim[i]) {
reserved_tim[i] = 0x00;
tim_frequencies[i] = 0x00;
} else {
never_reset_mask |= 1 << i;
}
}
tim_clock_disable(ALL_CLOCKS & ~(never_reset_mask));
}
pwmout_result_t common_hal_pulseio_pwmout_construct(pulseio_pwmout_obj_t* self,
const mcu_pin_obj_t* pin,
uint16_t duty,
uint32_t frequency,
bool variable_frequency) {
TIM_TypeDef * TIMx;
uint8_t tim_num = MP_ARRAY_SIZE(mcu_tim_pin_list);
bool tim_chan_taken = false;
bool tim_taken_f_mismatch = false;
bool var_freq_mismatch = false;
bool first_time_setup = true;
for (uint i = 0; i < tim_num; i++) {
const mcu_tim_pin_obj_t * l_tim = &mcu_tim_pin_list[i];
uint8_t l_tim_index = l_tim->tim_index - 1;
uint8_t l_tim_channel = l_tim->channel_index - 1;
//if pin is same
if (l_tim->pin == pin) {
//check if the timer has a channel active
if (reserved_tim[l_tim_index] != 0) {
//is it the same channel? (or all channels reserved by a var-freq)
if (reserved_tim[l_tim_index] & 1 << (l_tim_channel)) {
tim_chan_taken = true;
continue; //keep looking, might be another viable option
}
//If the frequencies are the same it's ok
if (tim_frequencies[l_tim_index] != frequency) {
tim_taken_f_mismatch = true;
continue; //keep looking
}
//you can't put a variable frequency on a partially reserved timer
if (variable_frequency) {
var_freq_mismatch = true;
continue; //keep looking
}
first_time_setup = false; //skip setting up the timer
}
//No problems taken, so set it up
self->tim = l_tim;
break;
}
}
//handle valid/invalid timer instance
if (self->tim != NULL) {
//create instance
TIMx = mcu_tim_banks[self->tim->tim_index - 1];
//reserve timer/channel
if (variable_frequency) {
reserved_tim[self->tim->tim_index - 1] = 0x0F;
} else {
reserved_tim[self->tim->tim_index - 1] |= 1 << (self->tim->channel_index - 1);
}
tim_frequencies[self->tim->tim_index - 1] = frequency;
} else { //no match found
if (tim_chan_taken) {
mp_raise_ValueError(translate("No more timers available on this pin."));
} else if (tim_taken_f_mismatch) {
mp_raise_ValueError(translate("Frequency must match existing PWMOut using this timer"));
} 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 for PWMOut"));
}
}
GPIO_InitTypeDef GPIO_InitStruct = {0};
GPIO_InitStruct.Pin = pin_mask(pin->number);
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
GPIO_InitStruct.Alternate = self->tim->altfn_index;
HAL_GPIO_Init(pin_port(pin->port), &GPIO_InitStruct);
tim_clock_enable(1 << (self->tim->tim_index - 1));
//translate channel into handle value
self->channel = 4 * (self->tim->channel_index - 1);
uint32_t prescaler = 0; //prescaler is 15 bit
uint32_t period = 0; //period is 16 bit
timer_get_optimal_divisors(&period, &prescaler, frequency,
timer_get_source_freq(self->tim->tim_index));
//Timer init
self->handle.Instance = TIMx;
self->handle.Init.Period = period - 1;
self->handle.Init.Prescaler = prescaler - 1;
self->handle.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
self->handle.Init.CounterMode = TIM_COUNTERMODE_UP;
self->handle.Init.RepetitionCounter = 0;
//only run init if this is the first instance of this timer
if (first_time_setup) {
if (HAL_TIM_PWM_Init(&self->handle) != HAL_OK) {
mp_raise_ValueError(translate("Could not initialize timer"));
}
}
//Channel/PWM init
self->chan_handle.OCMode = TIM_OCMODE_PWM1;
self->chan_handle.Pulse = timer_get_internal_duty(duty, period);
self->chan_handle.OCPolarity = TIM_OCPOLARITY_HIGH;
self->chan_handle.OCFastMode = TIM_OCFAST_DISABLE;
if (HAL_TIM_PWM_ConfigChannel(&self->handle, &self->chan_handle, self->channel) != HAL_OK) {
mp_raise_ValueError(translate("Could not initialize channel"));
}
if (HAL_TIM_PWM_Start(&self->handle, self->channel) != HAL_OK) {
mp_raise_ValueError(translate("Could not start PWM"));
}
self->variable_frequency = variable_frequency;
self->frequency = frequency;
self->duty_cycle = duty;
self->period = period;
return PWMOUT_OK;
}
void common_hal_pulseio_pwmout_never_reset(pulseio_pwmout_obj_t *self) {
for (size_t i = 0; i < TIM_BANK_ARRAY_LEN; i++) {
if (mcu_tim_banks[i] == self->handle.Instance) {
never_reset_tim[i] = true;
never_reset_pin_number(self->tim->pin->port, self->tim->pin->number);
break;
}
}
}
void common_hal_pulseio_pwmout_reset_ok(pulseio_pwmout_obj_t *self) {
for(size_t i = 0; i < TIM_BANK_ARRAY_LEN; i++) {
if (mcu_tim_banks[i] == self->handle.Instance) {
never_reset_tim[i] = false;
break;
}
}
}
bool common_hal_pulseio_pwmout_deinited(pulseio_pwmout_obj_t* self) {
return self->tim == NULL;
}
void common_hal_pulseio_pwmout_deinit(pulseio_pwmout_obj_t* self) {
if (common_hal_pulseio_pwmout_deinited(self)) {
return;
}
//var freq shuts down entire timer, others just their channel
if (self->variable_frequency) {
reserved_tim[self->tim->tim_index - 1] = 0x00;
} else {
reserved_tim[self->tim->tim_index - 1] &= ~(1 << self->tim->channel_index);
HAL_TIM_PWM_Stop(&self->handle, self->channel);
}
reset_pin_number(self->tim->pin->port,self->tim->pin->number);
self->tim = NULL;
//if reserved timer has no active channels, we can disable it
if (!reserved_tim[self->tim->tim_index - 1]) {
tim_frequencies[self->tim->tim_index - 1] = 0x00;
tim_clock_disable(1 << (self->tim->tim_index - 1));
}
}
void common_hal_pulseio_pwmout_set_duty_cycle(pulseio_pwmout_obj_t* self, uint16_t duty) {
uint32_t internal_duty_cycle = timer_get_internal_duty(duty, self->period);
__HAL_TIM_SET_COMPARE(&self->handle, self->channel, internal_duty_cycle);
self->duty_cycle = duty;
}
uint16_t common_hal_pulseio_pwmout_get_duty_cycle(pulseio_pwmout_obj_t* self) {
return self->duty_cycle;
}
void common_hal_pulseio_pwmout_set_frequency(pulseio_pwmout_obj_t* self, uint32_t frequency) {
//don't halt setup for the same frequency
if (frequency == self->frequency) {
return;
}
uint32_t prescaler = 0;
uint32_t period = 0;
timer_get_optimal_divisors(&period, &prescaler, frequency,
timer_get_source_freq(self->tim->tim_index));
//shut down
HAL_TIM_PWM_Stop(&self->handle, self->channel);
//Only change altered values
self->handle.Init.Period = period - 1;
self->handle.Init.Prescaler = prescaler - 1;
//restart everything, adjusting for new speed
if (HAL_TIM_PWM_Init(&self->handle) != HAL_OK) {
mp_raise_ValueError(translate("Could not re-init timer"));
}
self->chan_handle.Pulse = timer_get_internal_duty(self->duty_cycle, period);
if (HAL_TIM_PWM_ConfigChannel(&self->handle, &self->chan_handle, self->channel) != HAL_OK) {
mp_raise_ValueError(translate("Could not re-init channel"));
}
if (HAL_TIM_PWM_Start(&self->handle, self->channel) != HAL_OK) {
mp_raise_ValueError(translate("Could not restart PWM"));
}
tim_frequencies[self->tim->tim_index - 1] = frequency;
self->frequency = frequency;
self->period = period;
}
uint32_t common_hal_pulseio_pwmout_get_frequency(pulseio_pwmout_obj_t* self) {
return self->frequency;
}
bool common_hal_pulseio_pwmout_get_variable_frequency(pulseio_pwmout_obj_t* self) {
return self->variable_frequency;
}
STATIC void tim_clock_enable(uint16_t mask) {
#ifdef TIM1
if (mask & (1 << 0)) {
__HAL_RCC_TIM1_CLK_ENABLE();
}
#endif
#ifdef TIM2
if (mask & (1 << 1)) {
__HAL_RCC_TIM2_CLK_ENABLE();
}
#endif
#ifdef TIM3
if (mask & (1 << 2)) {
__HAL_RCC_TIM3_CLK_ENABLE();
}
#endif
#ifdef TIM4
if (mask & (1 << 3)) {
__HAL_RCC_TIM4_CLK_ENABLE();
}
#endif
#ifdef TIM5
if (mask & (1 << 4)) {
__HAL_RCC_TIM5_CLK_ENABLE();
}
#endif
//6 and 7 are reserved ADC timers
#ifdef TIM8
if (mask & (1 << 7)) {
__HAL_RCC_TIM8_CLK_ENABLE();
}
#endif
#ifdef TIM9
if (mask & (1 << 8)) {
__HAL_RCC_TIM9_CLK_ENABLE();
}
#endif
#ifdef TIM10
if (mask & (1 << 9)) {
__HAL_RCC_TIM10_CLK_ENABLE();
}
#endif
#ifdef TIM11
if (mask & (1 << 10)) {
__HAL_RCC_TIM11_CLK_ENABLE();
}
#endif
#ifdef TIM12
if (mask & (1 << 11)) {
__HAL_RCC_TIM12_CLK_ENABLE();
}
#endif
#ifdef TIM13
if (mask & (1 << 12)) {
__HAL_RCC_TIM13_CLK_ENABLE();
}
#endif
#ifdef TIM14
if (mask & (1 << 13)) {
__HAL_RCC_TIM14_CLK_ENABLE();
}
#endif
}
STATIC void tim_clock_disable(uint16_t mask) {
#ifdef TIM1
if (mask & (1 << 0)) {
__HAL_RCC_TIM1_CLK_DISABLE();
}
#endif
#ifdef TIM2
if (mask & (1 << 1)) {
__HAL_RCC_TIM2_CLK_DISABLE();
}
#endif
#ifdef TIM3
if (mask & (1 << 2)) {
__HAL_RCC_TIM3_CLK_DISABLE();
}
#endif
#ifdef TIM4
if (mask & (1 << 3)) {
__HAL_RCC_TIM4_CLK_DISABLE();
}
#endif
#ifdef TIM5
if (mask & (1 << 4)) {
__HAL_RCC_TIM5_CLK_DISABLE();
}
#endif
//6 and 7 are reserved ADC timers
#ifdef TIM8
if (mask & (1 << 7)) {
__HAL_RCC_TIM8_CLK_DISABLE();
}
#endif
#ifdef TIM9
if (mask & (1 << 8)) {
__HAL_RCC_TIM9_CLK_DISABLE();
}
#endif
#ifdef TIM10
if (mask & (1 << 9)) {
__HAL_RCC_TIM10_CLK_DISABLE();
}
#endif
#ifdef TIM11
if (mask & (1 << 10)) {
__HAL_RCC_TIM11_CLK_DISABLE();
}
#endif
#ifdef TIM12
if (mask & (1 << 11)) {
__HAL_RCC_TIM12_CLK_DISABLE();
}
#endif
#ifdef TIM13
if (mask & (1 << 12)) {
__HAL_RCC_TIM13_CLK_DISABLE();
}
#endif
#ifdef TIM14
if (mask & (1 << 13)) {
__HAL_RCC_TIM14_CLK_DISABLE();
}
#endif
}
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