Merge pull request #2103 from LMESTM/fix_pwmout_period

Fix pwmout period

Author: 0xc0170

hal/targets/hal/TARGET_STM/TARGET_STM32F0/TARGET_DISCO_F051R8/objects.h

@@ -93,13 +93,7 @@ struct i2c_s {
     I2CName  i2c;
 };
 
-struct pwmout_s {
-    PWMName pwm;
-    PinName pin;
-    uint32_t period;
-    uint32_t pulse;
-};
-
+#include "common_objects.h"
 #include "gpio_object.h"
 
 #ifdef __cplusplus

hal/targets/hal/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F030R8/objects.h

@@ -88,13 +88,7 @@ struct i2c_s {
     I2CName  i2c;
 };
 
-struct pwmout_s {
-    PWMName pwm;
-    PinName pin;
-    uint32_t period;
-    uint32_t pulse;
-};
-
+#include "common_objects.h"
 #include "gpio_object.h"
 
 #ifdef __cplusplus

hal/targets/hal/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F031K6/objects.h

@@ -88,13 +88,7 @@ struct i2c_s {
     I2CName  i2c;
 };
 
-struct pwmout_s {
-    PWMName pwm;
-    PinName pin;
-    uint32_t period;
-    uint32_t pulse;
-};
-
+#include "common_objects.h"
 #include "gpio_object.h"
 
 #ifdef __cplusplus

hal/targets/hal/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F042K6/objects.h

@@ -88,18 +88,12 @@ struct i2c_s {
     I2CName  i2c;
 };
 
-struct pwmout_s {
-    PWMName pwm;
-    PinName pin;
-    uint32_t period;
-    uint32_t pulse;
-};
-
 struct can_s {
     CANName can;
     int index;
 };
 
+#include "common_objects.h"
 #include "gpio_object.h"
 
 #ifdef __cplusplus

hal/targets/hal/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F070RB/objects.h

@@ -88,13 +88,7 @@ struct i2c_s {
     I2CName  i2c;
 };
 
-struct pwmout_s {
-    PWMName pwm;
-    PinName pin;
-    uint32_t period;
-    uint32_t pulse;
-};
-
+#include "common_objects.h"
 #include "gpio_object.h"
 
 #ifdef __cplusplus

hal/targets/hal/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F072RB/objects.h

@@ -93,18 +93,12 @@ struct i2c_s {
     I2CName  i2c;
 };
 
-struct pwmout_s {
-    PWMName pwm;
-    PinName pin;
-    uint32_t period;
-    uint32_t pulse;
-};
-
 struct can_s {
     CANName can;
     int index;
 };
 
+#include "common_objects.h"
 #include "gpio_object.h"
 
 #ifdef __cplusplus

hal/targets/hal/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F091RC/objects.h

@@ -93,18 +93,12 @@ struct i2c_s {
     I2CName  i2c;
 };
 
-struct pwmout_s {
-    PWMName pwm;
-    PinName pin;
-    uint32_t period;
-    uint32_t pulse;
-};
-
 struct can_s {
     CANName can;
     int index;
 };
 
+#include "common_objects.h"
 #include "gpio_object.h"
 
 #ifdef __cplusplus

hal/targets/hal/TARGET_STM/TARGET_STM32F0/common_objects.h

@@ -0,0 +1,57 @@
+/* mbed Microcontroller Library
+ *******************************************************************************
+ * Copyright (c) 2016, 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.
+ *******************************************************************************
+ */
+#ifndef MBED_COMMON_OBJECTS_H
+#define MBED_COMMON_OBJECTS_H
+
+#include "cmsis.h"
+#include "PortNames.h"
+#include "PeripheralNames.h"
+#include "PinNames.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct pwmout_s {
+    PWMName pwm;
+    PinName pin;
+    uint32_t prescaler;
+    uint32_t period;
+    uint32_t pulse;
+};
+
+#include "gpio_object.h"
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+

hal/targets/hal/TARGET_STM/TARGET_STM32F0/pwmout_api.c

@@ -75,6 +75,7 @@ void pwmout_init(pwmout_t* obj, PinName pin) {
     obj->pin = pin;
     obj->period = 0;
     obj->pulse = 0;
+    obj->prescaler = 1;
 
     pwmout_period_us(obj, 20000); // 20 ms per default
 }
@@ -101,7 +102,7 @@ void pwmout_write(pwmout_t* obj, float value) {
 
     // Configure channels
     sConfig.OCMode       = TIM_OCMODE_PWM1;
-    sConfig.Pulse        = obj->pulse;
+    sConfig.Pulse        = obj->pulse / obj->prescaler;
     sConfig.OCPolarity   = TIM_OCPOLARITY_HIGH;
     sConfig.OCNPolarity  = TIM_OCNPOLARITY_HIGH;
     sConfig.OCFastMode   = TIM_OCFAST_DISABLE;
@@ -265,18 +266,39 @@ void pwmout_period_us(pwmout_t* obj, int us) {
     // Update the SystemCoreClock variable
     SystemCoreClockUpdate();
 
-    TimHandle.Init.Period        = us - 1;
-    TimHandle.Init.Prescaler     = (uint16_t)(SystemCoreClock / 1000000) - 1; // 1 µs tick
+    /* 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;
-    HAL_TIM_PWM_Init(&TimHandle);
 
-    // Set duty cycle again
-    pwmout_write(obj, dc);
+    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);
 }
 

hal/targets/hal/TARGET_STM/TARGET_STM32F1/TARGET_BLUEPILL_F103C8/objects.h

@@ -89,19 +89,13 @@ struct i2c_s {
     uint32_t slave;
 };
 
-struct pwmout_s {
-    PWMName pwm;
-    PinName pin;
-    uint32_t period;
-    uint32_t pulse;
-};
-
 struct can_s {
     CANName can;
     int index;
 };
 
 #include "gpio_object.h"
+#include "common_objects.h"
 
 #ifdef __cplusplus
 }