Diff: targets/TARGET_STM/TARGET_STM32L0/pwmout_api.c

Revision:

149:156823d33999

Parent:

144:ef7eb2e8f9f7

diff -r 21d94c44109e -r 156823d33999 targets/TARGET_STM/TARGET_STM32L0/pwmout_api.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_STM/TARGET_STM32L0/pwmout_api.c	Fri Oct 28 11:17:30 2016 +0100
@@ -0,0 +1,204 @@
+/* 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"
+
+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);
+    MBED_ASSERT(obj->pwm != (PWMName)NC);
+
+    // Get the pin function and assign the used channel to the object
+    uint32_t function = pinmap_function(pin, PinMap_PWM);
+    MBED_ASSERT(function != (uint32_t)NC);
+    obj->channel = STM_PIN_CHANNEL(function);
+    obj->inverted = STM_PIN_INVERTED(function);
+
+    // Enable TIM clock
+    if (obj->pwm == PWM_2) __TIM2_CLK_ENABLE();
+#if defined(TIM3_BASE)
+    if (obj->pwm == PWM_3) __TIM3_CLK_ENABLE();
+#endif
+    if (obj->pwm == PWM_21) __TIM21_CLK_ENABLE();
+#if defined(TIM22_BASE)
+    if (obj->pwm == PWM_22) __TIM22_CLK_ENABLE();
+#endif
+
+    // Configure GPIO
+    pinmap_pinout(pin, PinMap_PWM);
+
+    obj->pin = pin;
+    obj->period = 0;
+    obj->pulse = 0;
+    obj->prescaler = 1;
+
+    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;
+
+    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 / obj->prescaler;
+    sConfig.OCPolarity   = TIM_OCPOLARITY_HIGH;
+    sConfig.OCFastMode   = TIM_OCFAST_ENABLE;
+
+    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 (HAL_TIM_PWM_ConfigChannel(&TimHandle, &sConfig, channel) != HAL_OK) {
+        error("Cannot initialize PWM");
+    }
+
+    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);
+
+    /* To make it simple, we use to possible prescaler values which lead to:
+     * pwm unit = 1us, period/pulse can be from 1us to 65535us
+     * or
+     * pwm unit = 500us, period/pulse can be from 500us to ~32.76sec
+     * Be careful that all the channels of a PWM shares the same prescaler
+     */
+    if (us >  0xFFFF) {
+        obj->prescaler = 500;
+    } else {
+        obj->prescaler = 1;
+    }
+    TimHandle.Init.Prescaler     = ((SystemCoreClock / 1000000) * obj->prescaler) - 1;
+
+    if (TimHandle.Init.Prescaler > 0xFFFF)
+        error("PWM: out of range prescaler");
+
+    TimHandle.Init.Period        = (us - 1) / obj->prescaler;
+    if (TimHandle.Init.Period > 0xFFFF)
+        error("PWM: out of range period");
+
+    TimHandle.Init.ClockDivision = 0;
+    TimHandle.Init.CounterMode   = TIM_COUNTERMODE_UP;
+
+    if (HAL_TIM_PWM_Init(&TimHandle) != HAL_OK) {
+        error("Cannot initialize PWM");
+    }
+
+    // Save for future use
+    obj->period = us;
+
+    // Set duty cycle again
+    pwmout_write(obj, dc);
+
+    __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