tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_STM/TARGET_STM32L0/pwmout_api.c

   1 /* mbed Microcontroller Library
   2  *******************************************************************************
   3  * Copyright (c) 2014, STMicroelectronics
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright notice,
  10  *    this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright notice,
  12  *    this list of conditions and the following disclaimer in the documentation
  13  *    and/or other materials provided with the distribution.
  14  * 3. Neither the name of STMicroelectronics nor the names of its contributors
  15  *    may be used to endorse or promote products derived from this software
  16  *    without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  19  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  21  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  24  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  25  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  26  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  27  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  *******************************************************************************
  29  */
  30 #include "pwmout_api.h"
  31
  32 #if DEVICE_PWMOUT
  33
  34 #include "cmsis.h"
  35 #include "pinmap.h"
  36 #include "mbed_error.h"
  37 #include "PeripheralPins.h"
  38
  39 static TIM_HandleTypeDef TimHandle;
  40
  41 void pwmout_init(pwmout_t* obj, PinName pin)
  42 {
  43     // Get the peripheral name from the pin and assign it to the object
  44     obj->pwm = (PWMName)pinmap_peripheral(pin, PinMap_PWM);
  45
  46     if (obj->pwm == (PWMName)NC) {
  47         error("PWM error: pinout mapping failed.");
  48     }
  49
  50     // Enable TIM clock
  51     if (obj->pwm == PWM_2) __TIM2_CLK_ENABLE();
  52 #if defined(TIM3_BASE)
  53     if (obj->pwm == PWM_3) __TIM3_CLK_ENABLE();
  54 #endif
  55     if (obj->pwm == PWM_21) __TIM21_CLK_ENABLE();
  56     if (obj->pwm == PWM_22) __TIM22_CLK_ENABLE();
  57
  58     // Configure GPIO
  59     pinmap_pinout(pin, PinMap_PWM);
  60
  61     obj->pin = pin;
  62     obj->period = 0;
  63     obj->pulse = 0;
  64
  65     pwmout_period_us(obj, 20000); // 20 ms per default
  66 }
  67
  68 void pwmout_free(pwmout_t* obj)
  69 {
  70     // Configure GPIO
  71     pin_function(obj->pin, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
  72 }
  73
  74 void pwmout_write(pwmout_t* obj, float value)
  75 {
  76     TIM_OC_InitTypeDef sConfig;
  77     int channel = 0;
  78
  79     TimHandle.Instance = (TIM_TypeDef *)(obj->pwm);
  80
  81     if (value < (float)0.0) {
  82         value = 0.0;
  83     } else if (value > (float)1.0) {
  84         value = 1.0;
  85     }
  86
  87     obj->pulse = (uint32_t)((float)obj->period * value);
  88
  89     // Configure channels
  90     sConfig.OCMode       = TIM_OCMODE_PWM1;
  91     sConfig.Pulse        = obj->pulse;
  92     sConfig.OCPolarity   = TIM_OCPOLARITY_HIGH;
  93     sConfig.OCFastMode   = TIM_OCFAST_ENABLE;
  94
  95     switch (obj->pin) {
  96         // Channels 1
  97         case PA_0:
  98         case PA_5:
  99         case PA_6:
 100         case PA_15:
 101         case PB_4:
 102         case PC_6:
 103             channel = TIM_CHANNEL_1;
 104             break;
 105         // Channels 2
 106         case PA_1:
 107         case PA_7:
 108         case PB_3:
 109         case PB_5:
 110         case PC_7:
 111             channel = TIM_CHANNEL_2;
 112             break;
 113         // Channels 3
 114         case PA_2:
 115         case PB_0:
 116         case PB_10:
 117         case PC_8:
 118             channel = TIM_CHANNEL_3;
 119             break;
 120         // Channels 4
 121         case PA_3:
 122         case PB_1:
 123         case PB_11:
 124         case PC_9:
 125             channel = TIM_CHANNEL_4;
 126             break;
 127         default:
 128             return;
 129     }
 130
 131     HAL_TIM_PWM_ConfigChannel(&TimHandle, &sConfig, channel);
 132     HAL_TIM_PWM_Start(&TimHandle, channel);
 133 }
 134
 135 float pwmout_read(pwmout_t* obj)
 136 {
 137     float value = 0;
 138     if (obj->period > 0) {
 139         value = (float)(obj->pulse) / (float)(obj->period);
 140     }
 141     return ((value > (float)1.0) ? (float)(1.0) : (value));
 142 }
 143
 144 void pwmout_period(pwmout_t* obj, float seconds)
 145 {
 146     pwmout_period_us(obj, seconds * 1000000.0f);
 147 }
 148
 149 void pwmout_period_ms(pwmout_t* obj, int ms)
 150 {
 151     pwmout_period_us(obj, ms * 1000);
 152 }
 153
 154 void pwmout_period_us(pwmout_t* obj, int us)
 155 {
 156     TimHandle.Instance = (TIM_TypeDef *)(obj->pwm);
 157
 158     float dc = pwmout_read(obj);
 159
 160     __HAL_TIM_DISABLE(&TimHandle);
 161
 162     TimHandle.Init.Period        = us - 1;
 163     TimHandle.Init.Prescaler     = (uint16_t)(SystemCoreClock / 1000000) - 1; // 1 us tick
 164     TimHandle.Init.ClockDivision = 0;
 165     TimHandle.Init.CounterMode   = TIM_COUNTERMODE_UP;
 166     HAL_TIM_PWM_Init(&TimHandle);
 167
 168     // Set duty cycle again
 169     pwmout_write(obj, dc);
 170
 171     // Save for future use
 172     obj->period = us;
 173
 174     __HAL_TIM_ENABLE(&TimHandle);
 175 }
 176
 177 void pwmout_pulsewidth(pwmout_t* obj, float seconds)
 178 {
 179     pwmout_pulsewidth_us(obj, seconds * 1000000.0f);
 180 }
 181
 182 void pwmout_pulsewidth_ms(pwmout_t* obj, int ms)
 183 {
 184     pwmout_pulsewidth_us(obj, ms * 1000);
 185 }
 186
 187 void pwmout_pulsewidth_us(pwmout_t* obj, int us)
 188 {
 189     float value = (float)us / (float)obj->period;
 190     pwmout_write(obj, value);
 191 }
 192
 193 #endif