File content as of revision 88:81f18c97d490:

/* mbed Microcontroller Library
 *******************************************************************************
 * Copyright (c) 2014, 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"

#include "cmsis.h"
#include "pinmap.h"
#include "error.h"
#include "stm32f4xx_hal.h"

static const PinMap PinMap_PWM[] = {
    {PB_3,  PWM_2, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM2)}, // TIM2_CH2
    {PB_4,  PWM_3, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3)}, // TIM3_CH1
    {PB_6,  PWM_4, STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM4)}, // TIM4_CH1
    {NC,    NC,    0}
};

static TIM_HandleTypeDef TimHandle;

void pwmout_init(pwmout_t* obj, PinName pin) {  
    // Get the peripheral name from the pin and assign it to the object
    obj->pwm = (PWMName)pinmap_peripheral(pin, PinMap_PWM);
  
    if (obj->pwm == (PWMName)NC) {
        error("PWM error: pinout mapping failed.");
    }
    
    // Enable TIM clock
    if (obj->pwm == PWM_2) __TIM2_CLK_ENABLE();
    if (obj->pwm == PWM_3) __TIM3_CLK_ENABLE();
    if (obj->pwm == PWM_4) __TIM4_CLK_ENABLE();
    
    // Configure GPIO
    pinmap_pinout(pin, PinMap_PWM);
    
    obj->pin = pin;
    obj->period = 0;
    obj->pulse = 0;
    
    pwmout_period_us(obj, 20000); // 20 ms per default
}

void pwmout_free(pwmout_t* obj) {
    TimHandle.Instance = (TIM_TypeDef *)(obj->pwm);
  
    HAL_TIM_PWM_DeInit(&TimHandle);
  
    pin_function(obj->pin, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));    
}

void pwmout_write(pwmout_t* obj, float value) {
    TIM_OC_InitTypeDef sConfig;
  
    TimHandle.Instance = (TIM_TypeDef *)(obj->pwm);
  
    if (value < 0.0) {
        value = 0.0;
    } else if (value > 1.0) {
        value = 1.0;
    }
   
    obj->pulse = (uint32_t)((float)obj->period * value);
    
    sConfig.OCMode     = TIM_OCMODE_PWM1;
    sConfig.OCFastMode = TIM_OCFAST_DISABLE;
    sConfig.OCPolarity = TIM_OCPOLARITY_HIGH;
    sConfig.Pulse      = obj->pulse;

    if (obj->pin == PB_3) {
        HAL_TIM_PWM_ConfigChannel(&TimHandle, &sConfig, TIM_CHANNEL_2);
        HAL_TIM_PWM_Start(&TimHandle, TIM_CHANNEL_2);
    }
    
    if ((obj->pin == PB_4) || (obj->pin == PB_6)) {
        HAL_TIM_PWM_ConfigChannel(&TimHandle, &sConfig, TIM_CHANNEL_1);
        HAL_TIM_PWM_Start(&TimHandle, TIM_CHANNEL_1);
    } 
}

float pwmout_read(pwmout_t* obj) {
    float value = 0;
    if (obj->period > 0) {
        value = (float)(obj->pulse) / (float)(obj->period);
    }
    return ((value > 1.0) ? (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);

    float dc = pwmout_read(obj);
  
    __HAL_TIM_DISABLE(&TimHandle);
      
    TimHandle.Init.Period        = us - 1;
    TimHandle.Init.Prescaler     = (uint16_t)(SystemCoreClock / 1000000) - 1; // 1 µs tick
    TimHandle.Init.ClockDivision = 0;
    TimHandle.Init.CounterMode   = TIM_COUNTERMODE_UP;
    HAL_TIM_PWM_Init(&TimHandle);

    // Set duty cycle again
    pwmout_write(obj, dc);

    // Save for future use  
    obj->period = us;
  
    __HAL_TIM_ENABLE(&TimHandle);
}

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);
}