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mbed-os/targets/TARGET_STM/pwmout_api.c

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/* mbed Microcontroller Library
*******************************************************************************
* Copyright (c) 2015, STMicroelectronics
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. Neither the name of STMicroelectronics nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*******************************************************************************
*/
#include "pwmout_api.h"
#if DEVICE_PWMOUT
#include "cmsis.h"
#include "pinmap.h"
#include "mbed_error.h"
#include "PeripheralPins.h"
#include "pwmout_device.h"
#include <math.h>
static TIM_HandleTypeDef TimHandle;
// Maximum counts per timer cycle.
// Note: Hardware can do 65536, but I don't believe you can have 100% duty cycle with 65536 counts/cycle.
#define MAX_COUNTS_PER_CYCLE 65535
// Maximum prescaler division possible
#define MAX_PRESCALER 65536
// Change to 1 to enable debug prints of what's being calculated.
// Must comment out the critical section calls in PwmOut to use.
#define STM_PWMOUT_DEBUG 0
#if STM_PWMOUT_DEBUG
#include <stdio.h>
#include <inttypes.h>
#endif
/* Convert STM32 Cube HAL channel to LL channel */
uint32_t TIM_ChannelConvert_HAL2LL(uint32_t channel, pwmout_t *obj)
{
#if !defined(PWMOUT_INVERTED_NOT_SUPPORTED)
if (obj->inverted) {
switch (channel) {
case TIM_CHANNEL_1 :
return LL_TIM_CHANNEL_CH1N;
case TIM_CHANNEL_2 :
return LL_TIM_CHANNEL_CH2N;
case TIM_CHANNEL_3 :
return LL_TIM_CHANNEL_CH3N;
#if defined(LL_TIM_CHANNEL_CH4N)
case TIM_CHANNEL_4 :
return LL_TIM_CHANNEL_CH4N;
#endif
default : /* Optional */
return 0;
}
} else
#endif
{
switch (channel) {
case TIM_CHANNEL_1 :
return LL_TIM_CHANNEL_CH1;
case TIM_CHANNEL_2 :
return LL_TIM_CHANNEL_CH2;
case TIM_CHANNEL_3 :
return LL_TIM_CHANNEL_CH3;
case TIM_CHANNEL_4 :
return LL_TIM_CHANNEL_CH4;
default : /* Optional */
return 0;
}
}
}
#if STATIC_PINMAP_READY
#define PWM_INIT_DIRECT pwmout_init_direct
void pwmout_init_direct(pwmout_t *obj, const PinMap *pinmap)
#else
#define PWM_INIT_DIRECT _pwmout_init_direct
static void _pwmout_init_direct(pwmout_t *obj, const PinMap *pinmap)
#endif
{
// Get the peripheral name from the pin and assign it to the object
obj->pwm = (PWMName)pinmap->peripheral;
MBED_ASSERT(obj->pwm != (PWMName)NC);
// Get the functions (timer channel, (non)inverted) from the pin and assign it to the object
uint32_t function = (uint32_t)pinmap->function;
MBED_ASSERT(function != (uint32_t)NC);
obj->channel = STM_PIN_CHANNEL(function);
obj->inverted = STM_PIN_INVERTED(function);
// Enable TIM clock
#if defined(TIM1_BASE)
if (obj->pwm == PWM_1) {
__HAL_RCC_TIM1_CLK_ENABLE();
}
#endif
#if defined(TIM2_BASE)
if (obj->pwm == PWM_2) {
__HAL_RCC_TIM2_CLK_ENABLE();
}
#endif
#if defined(TIM3_BASE)
if (obj->pwm == PWM_3) {
__HAL_RCC_TIM3_CLK_ENABLE();
}
#endif
#if defined(TIM4_BASE)
if (obj->pwm == PWM_4) {
__HAL_RCC_TIM4_CLK_ENABLE();
}
#endif
#if defined(TIM5_BASE)
if (obj->pwm == PWM_5) {
__HAL_RCC_TIM5_CLK_ENABLE();
}
#endif
#if defined(TIM8_BASE)
if (obj->pwm == PWM_8) {
__HAL_RCC_TIM8_CLK_ENABLE();
}
#endif
#if defined(TIM9_BASE)
if (obj->pwm == PWM_9) {
__HAL_RCC_TIM9_CLK_ENABLE();
}
#endif
#if defined(TIM10_BASE)
if (obj->pwm == PWM_10) {
__HAL_RCC_TIM10_CLK_ENABLE();
}
#endif
#if defined(TIM11_BASE)
if (obj->pwm == PWM_11) {
__HAL_RCC_TIM11_CLK_ENABLE();
}
#endif
#if defined(TIM12_BASE)
if (obj->pwm == PWM_12) {
__HAL_RCC_TIM12_CLK_ENABLE();
}
#endif
#if defined(TIM13_BASE)
if (obj->pwm == PWM_13) {
__HAL_RCC_TIM13_CLK_ENABLE();
}
#endif
#if defined(TIM14_BASE)
if (obj->pwm == PWM_14) {
__HAL_RCC_TIM14_CLK_ENABLE();
}
#endif
#if defined(TIM15_BASE)
if (obj->pwm == PWM_15) {
__HAL_RCC_TIM15_CLK_ENABLE();
}
#endif
#if defined(TIM16_BASE)
if (obj->pwm == PWM_16) {
__HAL_RCC_TIM16_CLK_ENABLE();
}
#endif
#if defined(TIM17_BASE)
if (obj->pwm == PWM_17) {
__HAL_RCC_TIM17_CLK_ENABLE();
}
#endif
#if defined(TIM18_BASE)
if (obj->pwm == PWM_18) {
__HAL_RCC_TIM18_CLK_ENABLE();
}
#endif
#if defined(TIM19_BASE)
if (obj->pwm == PWM_19) {
__HAL_RCC_TIM19_CLK_ENABLE();
}
#endif
#if defined(TIM20_BASE)
if (obj->pwm == PWM_20) {
__HAL_RCC_TIM20_CLK_ENABLE();
}
#endif
#if defined(TIM21_BASE)
if (obj->pwm == PWM_21) {
__HAL_RCC_TIM21_CLK_ENABLE();
}
#endif
#if defined(TIM22_BASE)
if (obj->pwm == PWM_22) {
__HAL_RCC_TIM22_CLK_ENABLE();
}
#endif
// Configure GPIO
pin_function(pinmap->pin, pinmap->function);
obj->pin = pinmap->pin;
obj->period = 0;
obj->compare_value = 0;
obj->top_count = 1;
pwmout_period_us(obj, 20000); // 20 ms per default
}
void pwmout_init(pwmout_t *obj, PinName pin)
{
int peripheral = (int)pinmap_peripheral(pin, PinMap_PWM);
int function = (int)pinmap_find_function(pin, PinMap_PWM);
const PinMap static_pinmap = {pin, peripheral, function};
PWM_INIT_DIRECT(obj, &static_pinmap);
}
void pwmout_free(pwmout_t *obj)
{
// Configure GPIO back to reset value
pin_function(obj->pin, STM_PIN_DATA(STM_MODE_ANALOG, GPIO_NOPULL, 0));
}
void pwmout_write(pwmout_t *obj, float value)
{
TIM_OC_InitTypeDef sConfig;
int channel = 0;
TimHandle.Instance = (TIM_TypeDef *)(obj->pwm);
if (value < (float)0.0) {
value = 0.0;
} else if (value > (float)1.0) {
value = 1.0;
}
// Calculate the correct compare value. The PWM output changes to 0 once the counter becomes
// >= the compare value.
// Examples:
// - if value is .999 and counts is 3, we want to write 3 so the PWM is on all the time
// - if value is .33 and counts is 3, we want to write 1 so that we turn off after the counter becomes 1.
// - if value is .1 and counts is 3, that rounds to 0 so we want to write 0 so that the PWM is off all the time
obj->compare_value = lroundf((float)obj->top_count * value);
#if STM_PWMOUT_DEBUG
printf("Setting compare value to %" PRIu32 "\n", obj->compare_value);
#endif
// Configure channels
sConfig.OCMode = TIM_OCMODE_PWM1;
sConfig.Pulse = obj->compare_value;
sConfig.OCPolarity = TIM_OCPOLARITY_HIGH;
sConfig.OCFastMode = TIM_OCFAST_DISABLE;
#if defined(TIM_OCIDLESTATE_RESET)
sConfig.OCIdleState = TIM_OCIDLESTATE_RESET;
#endif
#if defined(TIM_OCNIDLESTATE_RESET)
sConfig.OCNPolarity = TIM_OCNPOLARITY_HIGH;
sConfig.OCNIdleState = TIM_OCNIDLESTATE_RESET;
#endif
switch (obj->channel) {
case 1:
channel = TIM_CHANNEL_1;
break;
case 2:
channel = TIM_CHANNEL_2;
break;
case 3:
channel = TIM_CHANNEL_3;
break;
case 4:
channel = TIM_CHANNEL_4;
break;
default:
return;
}
if (LL_TIM_CC_IsEnabledChannel(TimHandle.Instance, TIM_ChannelConvert_HAL2LL(channel, obj)) == 0) {
// If channel is not enabled, proceed to channel configuration
if (HAL_TIM_PWM_ConfigChannel(&TimHandle, &sConfig, channel) != HAL_OK) {
error("Cannot initialize PWM\n");
}
} else {
// If channel already enabled, only update compare value to avoid glitch
__HAL_TIM_SET_COMPARE(&TimHandle, channel, sConfig.Pulse);
return;
}
#if !defined(PWMOUT_INVERTED_NOT_SUPPORTED)
if (obj->inverted) {
HAL_TIMEx_PWMN_Start(&TimHandle, channel);
} else
#endif
{
HAL_TIM_PWM_Start(&TimHandle, channel);
}
}
float pwmout_read(pwmout_t *obj)
{
float value = 0;
if (obj->period > 0) {
value = (float)(obj->compare_value) / (float)(obj->top_count);
}
return ((value > (float)1.0) ? (float)(1.0) : (value));
}
void pwmout_period(pwmout_t *obj, float seconds)
{
pwmout_period_us(obj, seconds * 1000000.0f);
}
void pwmout_period_ms(pwmout_t *obj, int ms)
{
pwmout_period_us(obj, ms * 1000);
}
void pwmout_period_us(pwmout_t *obj, int us)
{
TimHandle.Instance = (TIM_TypeDef *)(obj->pwm);
RCC_ClkInitTypeDef RCC_ClkInitStruct;
uint32_t PclkFreq = 0;
uint32_t APBxCLKDivider = RCC_HCLK_DIV1;
float dc = pwmout_read(obj);
uint8_t i = 0;
__HAL_TIM_DISABLE(&TimHandle);
// Get clock configuration
// Note: PclkFreq contains here the Latency (not used after)
HAL_RCC_GetClockConfig(&RCC_ClkInitStruct, &PclkFreq);
/* Parse the pwm / apb mapping table to find the right entry */
while (pwm_apb_map_table[i].pwm != obj->pwm) {
i++;
}
if (pwm_apb_map_table[i].pwm == 0) {
error("Unknown PWM instance");
}
if (pwm_apb_map_table[i].pwmoutApb == PWMOUT_ON_APB1) {
PclkFreq = HAL_RCC_GetPCLK1Freq();
APBxCLKDivider = RCC_ClkInitStruct.APB1CLKDivider;
} else {
#if !defined(PWMOUT_APB2_NOT_SUPPORTED)
PclkFreq = HAL_RCC_GetPCLK2Freq();
APBxCLKDivider = RCC_ClkInitStruct.APB2CLKDivider;
#endif
}
// TIMxCLK = PCLKx when the APB prescaler = 1 else TIMxCLK = 2 * PCLKx
uint32_t timxClk;
if (APBxCLKDivider == RCC_HCLK_DIV1) {
timxClk = PclkFreq;
} else {
timxClk = PclkFreq * 2;
}
// To generate the desired frequency, we have 2 knobs to play with: the reload value and the
// duty cycle. We generally want to have the reload value as high as possible since that will
// give the best duty cycle resolution at high frequencies.
// Step 1: Calculate the smallest prescaler that will allow the desired period to be achieved by
// tuning the reload value.
// (prescaler * reloadValue) / (timxClk) = period
// prescaler = (period * timxClk) / reloadValue
// minimum needed prescaler (floating point) = (period * timxClk) / 65536
const float periodSeconds = us * 1e-6f;
const uint32_t prescaler = ceilf(periodSeconds * timxClk / MAX_COUNTS_PER_CYCLE);
MBED_ASSERT(prescaler <= MAX_PRESCALER);
// Step 2: Calculate top count based on determined prescaler
// reloadValue = period * timxClk / prescaler
uint32_t topCount = lroundf(periodSeconds * timxClk / prescaler);
MBED_ASSERT(topCount <= MAX_COUNTS_PER_CYCLE);
#if STM_PWMOUT_DEBUG
printf("Setting prescaler to %" PRIu32 " and top count to %" PRIu32 "\n", prescaler, topCount);
#endif
TimHandle.Init.Prescaler = prescaler - 1; // value of 0 means divide by 1
TimHandle.Init.Period = topCount - 1; // value of 0 means count once
TimHandle.Init.ClockDivision = 0; // Dead time generators and digital filters use CK_INT directly
TimHandle.Init.CounterMode = TIM_COUNTERMODE_UP;
if (HAL_TIM_PWM_Init(&TimHandle) != HAL_OK) {
error("Cannot initialize PWM\n");
}
// Save for future use
obj->period = us;
obj->top_count = topCount;
// Set duty cycle again
pwmout_write(obj, dc);
__HAL_TIM_ENABLE(&TimHandle);
}
int pwmout_read_period_us(pwmout_t *obj)
{
return obj->period;
}
void pwmout_pulsewidth(pwmout_t *obj, float seconds)
{
pwmout_pulsewidth_us(obj, seconds * 1000000.0f);
}
void pwmout_pulsewidth_ms(pwmout_t *obj, int ms)
{
pwmout_pulsewidth_us(obj, ms * 1000);
}
void pwmout_pulsewidth_us(pwmout_t *obj, int us)
{
float value = (float)us / (float)obj->period;
pwmout_write(obj, value);
}
int pwmout_read_pulsewidth_us(pwmout_t *obj)
{
float pwm_duty_cycle = pwmout_read(obj);
return lroundf(pwm_duty_cycle * (float)obj->period);
}
const PinMap *pwmout_pinmap()
{
return PinMap_PWM;
}
#endif
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