neorv32/sw/lib/source/neorv32_pwm.c

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2024-02-24 08:25:27 +00:00
// #################################################################################################
// # << NEORV32: neorv32_pwm.c - Pulse Width Modulation Controller (PWM) HW Driver >> #
// # ********************************************************************************************* #
// # BSD 3-Clause License #
// # #
// # Copyright (c) 2023, Stephan Nolting. 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 the copyright holder 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. #
// # ********************************************************************************************* #
// # The NEORV32 Processor - https://github.com/stnolting/neorv32 (c) Stephan Nolting #
// #################################################################################################
/**********************************************************************//**
* @file neorv32_pwm.c
* @brief Pulse-Width Modulation Controller (PWM) HW driver source file.
*
* @note These functions should only be used if the PWM unit was synthesized (IO_PWM_EN = true).
**************************************************************************/
#include "neorv32.h"
#include "neorv32_pwm.h"
/**********************************************************************//**
* Check if PWM unit was synthesized.
*
* @return 0 if PWM was not synthesized, 1 if PWM is available.
**************************************************************************/
int neorv32_pwm_available(void) {
if (NEORV32_SYSINFO->SOC & (1 << SYSINFO_SOC_IO_PWM)) {
return 1;
}
else {
return 0;
}
}
/**********************************************************************//**
* Enable and configure pulse width modulation controller.
* The PWM control register bits are listed in #NEORV32_PWM_CTRL_enum.
*
* @param[in] prsc Clock prescaler select (0..7). See #NEORV32_CLOCK_PRSC_enum.
**************************************************************************/
void neorv32_pwm_setup(int prsc) {
NEORV32_PWM->CTRL = 0; // reset
uint32_t ct_enable = 1;
ct_enable = ct_enable << PWM_CTRL_EN;
uint32_t ct_prsc = (uint32_t)(prsc & 0x07);
ct_prsc = ct_prsc << PWM_CTRL_PRSC0;
NEORV32_PWM->CTRL = ct_enable | ct_prsc;
}
/**********************************************************************//**
* Disable pulse width modulation controller.
**************************************************************************/
void neorv32_pwm_disable(void) {
NEORV32_PWM->CTRL &= ~((uint32_t)(1 << PWM_CTRL_EN));
}
/**********************************************************************//**
* Enable pulse width modulation controller.
**************************************************************************/
void neorv32_pwm_enable(void) {
NEORV32_PWM->CTRL |= ((uint32_t)(1 << PWM_CTRL_EN));
}
/**********************************************************************//**
* Get number of implemented channels.
* @warning This function will override all duty cycle configuration registers.
*
* @return Number of implemented channels.
**************************************************************************/
int neorv32_pmw_get_num_channels(void) {
neorv32_pwm_disable();
int i = 0;
uint32_t cnt = 0;
for (i=0; i<12; i++) {
neorv32_pwm_set(i, 1);
cnt += neorv32_pwm_get(i);
}
return (int)cnt;
}
/**********************************************************************//**
* Set duty cycle for channel.
*
* @param[in] channel Channel select (0..11).
* @param[in] dc Duty cycle (8-bit, LSB-aligned).
**************************************************************************/
void neorv32_pwm_set(int channel, uint8_t dc) {
if (channel > 11) {
return; // out-of-range
}
const uint32_t dc_mask = 0xff;
uint32_t dc_new = (uint32_t)dc;
uint32_t tmp = NEORV32_PWM->DC[channel/4];
tmp &= ~(dc_mask << ((channel % 4) * 8)); // clear previous duty cycle
tmp |= dc_new << ((channel % 4) * 8); // set new duty cycle
NEORV32_PWM->DC[channel/4] = tmp;
}
/**********************************************************************//**
* Get duty cycle from channel.
*
* @param[in] channel Channel select (0..11).
* @return Duty cycle (8-bit, LSB-aligned) of channel 'channel'.
**************************************************************************/
uint8_t neorv32_pwm_get(int channel) {
if (channel > 11) {
return 0; // out of range
}
uint32_t rd = NEORV32_PWM->DC[channel/4] >> (((channel % 4) * 8));
return (uint8_t)rd;
}