Diff: mbed-dev/targets/TARGET_ONSEMI/TARGET_NCS36510/pwmout_api.c

Revision:

18:6a4db94011d3

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-dev/targets/TARGET_ONSEMI/TARGET_NCS36510/pwmout_api.c	Sun May 14 23:18:57 2017 +0000
@@ -0,0 +1,209 @@
+/**
+ ******************************************************************************
+ * @file pwmout_api.c
+ * @brief Implementation of a PWM driver
+ * @internal
+ * @author ON Semiconductor
+ * $Rev:
+ * $Date:
+ ******************************************************************************
+ * Copyright 2016 Semiconductor Components Industries LLC (d/b/a “ON Semiconductor”).
+ * All rights reserved.  This software and/or documentation is licensed by ON Semiconductor
+ * under limited terms and conditions.  The terms and conditions pertaining to the software
+ * and/or documentation are available at http://www.onsemi.com/site/pdf/ONSEMI_T&C.pdf
+ * (“ON Semiconductor Standard Terms and Conditions of Sale, Section 8 Software”) and
+ * if applicable the software license agreement.  Do not use this software and/or
+ * documentation unless you have carefully read and you agree to the limited terms and
+ * conditions.  By using this software and/or documentation, you agree to the limited
+ * terms and conditions.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS IS".  NO WARRANTIES, WHETHER EXPRESS, IMPLIED
+ * OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
+ * ON SEMICONDUCTOR SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL,
+ * INCIDENTAL, OR CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
+ * @endinternal
+*/
+#include "pwmout_api.h"
+#include "PeripheralPins.h"
+#include "mbed_assert.h"
+#include "clock.h"
+
+#if DEVICE_PWMOUT
+
+/**
+ * \defgroup hal_pwmout Pwmout hal functions
+ * @{
+ */
+
+/** Initialize the pwm out peripheral and configure the pin
+ *
+ * @param obj The pwmout object to initialize
+ * @param pin The pwmout pin to initialize
+ */
+void pwmout_init(pwmout_t *obj, PinName pin)
+{
+    /* Get the base address of the PWM register using the pinmap functions ; pwmout_s struct contains base address only */
+    PWMName pwm;
+
+    pwm = (PWMName)pinmap_peripheral(pin, PinMap_PWM);
+    MBED_ASSERT(pwm != (PWMName)NC);
+
+    pinmap_pinout(pin, PinMap_PWM);
+
+    obj->pwmReg = (PwmReg_pt)pwm;
+    MBED_ASSERT(obj->pwmReg != 0x00000000);
+
+    CLOCK_ENABLE(CLOCK_PWM);
+
+    /* Configuration parameters of duty cycle 0x4000B000, and prescaler 0x4000B00C, shall be set to default values */
+    /* Duty cycle shall be 50% and prescaler shall be disabled by default */
+    obj->pwmReg->DUTYCYCLE = 0x80;
+
+    /* Write the PWM output enable register 0x4000B004, to 1 */
+    obj->pwmReg->PWM_ENABLE = 0x1;
+
+    obj->pwmReg->PRESCALE_DISABLE = 0x1;
+
+}
+
+/** Deinitialize the pwmout object
+ *
+ * @param obj The pwmout object
+ */
+void pwmout_free(pwmout_t *obj)
+{
+    /* Write the PWM output disable register 0x4000B008, to 1 */
+    obj->pwmReg->PWM_DISABLE = 0x1;
+}
+
+/** Set the output duty-cycle in range <0.0f, 1.0f>
+ *
+ * Value 0.0f represents 0 percentage, 1.0f represents 100 percent.
+ * @param obj     The pwmout object
+ * @param percent The floating-point percentage number
+ */
+void pwmout_write(pwmout_t *obj, float percent)
+{
+    if (percent == 0.0) {
+        obj->pwmReg->DUTYCYCLE = 0x00;
+    } else if (percent == 1.0) {
+        obj->pwmReg->DUTYCYCLE = 0xFF;
+    } else {
+        /* Write the duty cycle config register 0x4000B000, with the value passed on */
+        /* ((percent * 255) + 1) is the duty cycle. Plus 1 is for accounting for round off errors; like a ceil function */
+        obj->pwmReg->DUTYCYCLE = (uint8_t)((percent * 255) + 1);
+    }
+}
+
+/** Read the current float-point output duty-cycle
+ *
+ * @param obj The pwmout object
+ * @return A floating-point output duty-cycle
+ */
+float pwmout_read(pwmout_t *obj)
+{
+    float retVal = 0.0;
+    float dc = 0.0;
+
+    /* Read out the value of duty cycle register 0x4000B000 and return as a percent */
+    /* Read value / 255 is the percent returned */
+    dc = obj->pwmReg->DUTYCYCLE;
+    retVal = dc/ (float)255;
+
+    return(retVal);
+}
+
+/** Set the PWM period specified in seconds, keeping the duty cycle the same
+ *
+ * Periods smaller than microseconds (the lowest resolution) are set to zero.
+ * @param obj     The pwmout object
+ * @param seconds The floating-point seconds period
+ */
+void pwmout_period(pwmout_t *obj, float seconds)
+{
+    /* Cannot be configured, prescaler is either 256 or 4096 */
+    return;
+}
+
+/** Set the PWM period specified in miliseconds, keeping the duty cycle the same
+ *
+ * @param obj The pwmout object
+ * @param ms  The milisecond period
+ */
+void pwmout_period_ms(pwmout_t *obj, int ms)
+{
+    /* Cannot be configured, prescaler is either 256 or 4096 */
+    return;
+}
+
+/** Set the PWM period specified in microseconds, keeping the duty cycle the same
+ *
+ * @param obj The pwmout object
+ * @param us  The microsecond period
+ */
+void pwmout_period_us(pwmout_t *obj, int us)
+{
+    /* Cannot be configured, prescaler is either 256 or 4096 */
+    return;
+}
+
+/** Set the PWM pulsewidth specified in seconds, keeping the period the same.
+ *
+ * @param obj     The pwmout object
+ * @param seconds The floating-point pulsewidth in seconds
+ */
+void pwmout_pulsewidth(pwmout_t *obj, float seconds)
+{
+    /* Pulse width can never be in seconds since the period
+    * itself is limited to either 8uSec or 128uSec
+    */
+    return;
+}
+
+/** Set the PWM pulsewidth specified in miliseconds, keeping the period the same.
+ *
+ * @param obj The pwmout object
+ * @param ms  The floating-point pulsewidth in miliseconds
+ */
+void pwmout_pulsewidth_ms(pwmout_t *obj, int ms)
+{
+
+    /* Pulse width can never be in seconds since the period
+    * itself is limited to either 8uSec or 128uSec
+    */
+    return;
+}
+
+/** Set the PWM pulsewidth specified in microseconds, keeping the period the same.
+ *
+ * @param obj The pwmout object
+ * @param us  The floating-point pulsewidth in microseconds
+ */
+void pwmout_pulsewidth_us(pwmout_t *obj, int us)
+{
+    int pulseWidth = 0;
+
+    /* Check if the uSec value is greater than 128uSec, if so reject */
+    if (us > 128) {
+        return;
+    }
+    /* If pulsewidth is less than 128uSec, set the prescaler to 4096
+     * by enabling prescale register 0x4000B00C to 1 */
+    obj->pwmReg->PRESCALE_ENABLE = 0x1;
+
+    /* Calculate the duty cycle based on the width of the pulse */
+    /* ((255 * us) / 128) + 1 = duty cycle */
+    pulseWidth = (int)((float)(255 * us)/(float)128) + 1;
+    if (us == 0) {
+        obj->pwmReg->DUTYCYCLE = 0x0;
+    } else if (us == 128) {
+        obj->pwmReg->DUTYCYCLE = 0xFF;
+    } else {
+        obj->pwmReg->DUTYCYCLE = (uint8_t)pulseWidth;
+    }
+}
+
+/**@}*/
+
+#endif // DEVICE_PWMOUT