Lee Kai Xuan
mbed-os
Fork of
mbed-os
by 
erkin yucel
Diff: targets/TARGET_STM/TARGET_STM32L1/pwmout_api.c
- Revision:
- 0:f269e3021894
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_STM/TARGET_STM32L1/pwmout_api.c Sun Oct 23 15:10:02 2016 +0000
@@ -0,0 +1,221 @@
+/* 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_2) __TIM2_CLK_ENABLE();
+ if (obj->pwm == PWM_3) __TIM3_CLK_ENABLE();
+ if (obj->pwm == PWM_4) __TIM4_CLK_ENABLE();
+ if (obj->pwm == PWM_5) __TIM5_CLK_ENABLE();
+ if (obj->pwm == PWM_9) __TIM9_CLK_ENABLE();
+ if (obj->pwm == PWM_10) __TIM10_CLK_ENABLE();
+ if (obj->pwm == PWM_11) __TIM11_CLK_ENABLE();
+
+ // 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->pin) {
+ // Channels 1
+ case PA_6:
+ case PB_4:
+ case PB_6:
+ case PB_12:
+ case PB_13:
+ case PB_15:
+ case PC_6:
+ channel = TIM_CHANNEL_1;
+ break;
+ // Channels 2
+ case PA_1:
+ case PA_7:
+ case PB_3:
+ case PB_5:
+ case PB_7:
+ case PB_14:
+ case PC_7:
+ channel = TIM_CHANNEL_2;
+ break;
+ // Channels 3
+ case PA_2:
+ case PB_0:
+ case PB_8:
+ case PB_10:
+ case PC_8:
+ channel = TIM_CHANNEL_3;
+ break;
+ // Channels 4
+ case PA_3:
+ case PB_1:
+ case PB_9:
+ case PB_11:
+ case PC_9:
+ channel = TIM_CHANNEL_4;
+ break;
+ default:
+ return;
+ }
+
+ HAL_TIM_PWM_ConfigChannel(&TimHandle, &sConfig, channel);
+ 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