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Diff: targets/TARGET_ONSEMI/TARGET_NCS36510/pwmout_api.c
- Revision:
- 149:156823d33999
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- 147:30b64687e01f
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/targets/TARGET_ONSEMI/TARGET_NCS36510/pwmout_api.c Fri Oct 28 11:17:30 2016 +0100 @@ -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.WORD = 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.WORD = 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