File content as of revision 635:a11c0372f0ba:

/* 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"

#if DEVICE_PWMOUT

#include "cmsis.h"
#include "pinmap.h"
#include "mbed_error.h"
#include "PeripheralPins.h"

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_1) __TIM1_CLK_ENABLE();
    if (obj->pwm == PWM_2) __TIM2_CLK_ENABLE();
    if (obj->pwm == PWM_3) __TIM3_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)
{
    // Configure GPIO
    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;
    int channel = 0;
    int complementary_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;
    }

    obj->pulse = (uint32_t)((float)obj->period * value);

    // Configure channels
    sConfig.OCMode       = TIM_OCMODE_PWM1;
    sConfig.Pulse        = obj->pulse;
    sConfig.OCPolarity   = TIM_OCPOLARITY_HIGH;
    sConfig.OCNPolarity  = TIM_OCNPOLARITY_HIGH;
    sConfig.OCFastMode   = TIM_OCFAST_DISABLE;
    sConfig.OCIdleState  = TIM_OCIDLESTATE_RESET;
    sConfig.OCNIdleState = TIM_OCNIDLESTATE_RESET;

    switch (obj->pin) {

        // Channels 1
        case PA_6:
        case PA_8:
        case PA_15:
        case PB_4:
        case PC_6:
            channel = TIM_CHANNEL_1;
            break;

        // Channels 1N
        case PB_13:
            channel = TIM_CHANNEL_1;
            complementary_channel = 1;
            break;

        // Channels 2
        case PA_1:
        case PA_7:
        case PA_9:
        case PB_3:
        case PB_5:
        case PC_7:
            channel = TIM_CHANNEL_2;
            break;

        // Channels 2N
        case PB_14:
            channel = TIM_CHANNEL_2;
            complementary_channel = 1;
            break;

        // Channels 3
        case PA_2:
        case PA_10:
        case PB_0:
        case PB_10:
        case PC_8:
            channel = TIM_CHANNEL_3;
            break;

        // Channels 3N
        case PB_15:
            channel = TIM_CHANNEL_3;
            complementary_channel = 1;
            break;

        // Channels 4
        case PA_3:
        case PA_11:
        case PB_1:
        case PB_11:
        case PC_9:
            channel = TIM_CHANNEL_4;
            break;

        default:
            return;
    }

    HAL_TIM_PWM_ConfigChannel(&TimHandle, &sConfig, channel);

    if (complementary_channel) {
        HAL_TIMEx_PWMN_Start(&TimHandle, channel);
    } else {
        HAL_TIM_PWM_Start(&TimHandle, channel);
    }
}

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

    float dc = pwmout_read(obj);

    __HAL_TIM_DISABLE(&TimHandle);

    // Update the SystemCoreClock variable
    SystemCoreClockUpdate();

    TimHandle.Init.Period        = us - 1;
    TimHandle.Init.Prescaler     = (uint16_t)(SystemCoreClock / 1000000) - 1; // 1 us 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);
}

#endif