circuitpython/ports/nrf/common-hal/pulseio/PWMOut.c

242 lines
6.2 KiB
C
Raw Normal View History

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2017 Scott Shawcroft for Adafruit Industries
* Copyright (c) 2016 Damien P. George
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <stdint.h>
#include "nrf.h"
#include "py/runtime.h"
#include "common-hal/pulseio/PWMOut.h"
#include "nrf_gpio.h"
#include "shared-bindings/pulseio/PWMOut.h"
2018-08-16 17:21:44 -04:00
#include "supervisor/shared/translate.h"
#define PWM_MAX_MODULE 3
#define PWM_MAX_CHANNEL 4
#define PWM_MAX_FREQ (16000000)
NRF_PWM_Type* const pwm_arr[PWM_MAX_MODULE] = { NRF_PWM0, NRF_PWM1, NRF_PWM2 };
uint16_t _seq0[PWM_MAX_MODULE][PWM_MAX_CHANNEL];
static int pin2channel(NRF_PWM_Type* pwm, uint8_t pin)
{
for(int i=0; i < PWM_MAX_CHANNEL; i++)
{
if ( pwm->PSEL.OUT[i] == ((uint32_t)pin) ) return i;
}
return -1;
}
static int find_free_channel(NRF_PWM_Type* pwm)
{
for(int i=0; i < PWM_MAX_CHANNEL; i++)
{
if (pwm->PSEL.OUT[i] == 0xFFFFFFFFUL)
{
return i;
}
}
return -1;
}
static bool pwm_is_unused(NRF_PWM_Type* pwm)
{
for(int i=0; i < PWM_MAX_CHANNEL; i++)
{
if (pwm->PSEL.OUT[i] != 0xFFFFFFFFUL)
{
return false;
}
}
return true;
}
static void find_new_pwm(pulseio_pwmout_obj_t* self)
{
// First find unused PWM module
for(int i=0; i<PWM_MAX_MODULE; i++)
{
if ( pwm_is_unused(pwm_arr[i]) )
{
self->pwm = pwm_arr[i];
self->channel = 0;
return;
}
}
// Find available channel in a using PWM
for(int i=0; i<PWM_MAX_MODULE; i++)
{
int ch = find_free_channel(pwm_arr[i]);
if ( ch >= 0 )
{
self->pwm = pwm_arr[i];
self->channel = (uint8_t) ch;
return;
}
}
}
void pwmout_reset(void)
{
for(int i=0; i<PWM_MAX_MODULE; i++)
{
NRF_PWM_Type* pwm = pwm_arr[i];
pwm->MODE = PWM_MODE_UPDOWN_Up;
pwm->DECODER = PWM_DECODER_LOAD_Individual;
pwm->LOOP = 0;
pwm->PRESCALER = PWM_PRESCALER_PRESCALER_DIV_1; // default is 500 hz
pwm->COUNTERTOP = (PWM_MAX_FREQ/500); // default is 500 hz
pwm->SEQ[0].PTR = (uint32_t) _seq0[i];
pwm->SEQ[0].CNT = PWM_MAX_CHANNEL; // default mode is Individual --> count must be 4
pwm->SEQ[0].REFRESH = 0;
pwm->SEQ[0].ENDDELAY = 0;
pwm->SEQ[1].PTR = 0;
pwm->SEQ[1].CNT = 0;
pwm->SEQ[1].REFRESH = 0;
pwm->SEQ[1].ENDDELAY = 0;
for(int ch =0; ch < PWM_MAX_CHANNEL; ch++)
{
_seq0[i][ch] = (1UL << 15); // polarity = 0
}
}
}
void common_hal_pulseio_pwmout_construct(pulseio_pwmout_obj_t* self,
const mcu_pin_obj_t* pin,
uint16_t duty,
uint32_t frequency,
bool variable_frequency) {
self->pwm = NULL;
self->pin = pin;
// check if mapped to PWM channel already
for(int i=0; i<PWM_MAX_MODULE; i++)
{
int ch = pin2channel(pwm_arr[i], pin->number);
if ( ch >= 0 )
{
self->pwm = pwm_arr[i];
self->channel = (uint8_t) ch;
break;
}
}
// Haven't mapped before
if ( !self->pwm )
{
find_new_pwm(self);
}
if (self->pwm)
{
nrf_gpio_cfg_output(pin->number);
// disable before mapping pin channel
self->pwm->ENABLE = 0;
self->pwm->PSEL.OUT[self->channel] = pin->number;
self->pwm->COUNTERTOP = (PWM_MAX_FREQ/frequency);
self->freq = frequency;
self->variable_freq = variable_frequency;
self->pwm->ENABLE = 1;
common_hal_pulseio_pwmout_set_duty_cycle(self, duty);
}
}
bool common_hal_pulseio_pwmout_deinited(pulseio_pwmout_obj_t* self) {
return self->pwm == NULL;
}
void common_hal_pulseio_pwmout_deinit(pulseio_pwmout_obj_t* self) {
if (common_hal_pulseio_pwmout_deinited(self)) {
return;
}
self->pwm->ENABLE = 0;
self->pwm->PSEL.OUT[self->channel] = 0xFFFFFFFFUL;
// re-enable PWM module if there is other active channel
for(int i=0; i < PWM_MAX_CHANNEL; i++)
{
if (self->pwm->PSEL.OUT[i] != 0xFFFFFFFFUL)
{
self->pwm->ENABLE = 1;
break;
}
}
nrf_gpio_cfg_default(self->pin->number);
self->pwm = NULL;
self->pin = mp_const_none;
}
void common_hal_pulseio_pwmout_set_duty_cycle(pulseio_pwmout_obj_t* self, uint16_t duty) {
self->duty = duty;
uint16_t* p_value = ((uint16_t*)self->pwm->SEQ[0].PTR) + self->channel;
*p_value = ((duty * self->pwm->COUNTERTOP) / 0xFFFF) | (1 << 15);
self->pwm->TASKS_SEQSTART[0] = 1;
}
uint16_t common_hal_pulseio_pwmout_get_duty_cycle(pulseio_pwmout_obj_t* self) {
return self->duty;
}
void common_hal_pulseio_pwmout_set_frequency(pulseio_pwmout_obj_t* self, uint32_t frequency) {
if (frequency == 0 || frequency > 16000000) {
2018-08-16 17:21:44 -04:00
mp_raise_ValueError(translate("Invalid PWM frequency"));
}
self->freq = frequency;
self->pwm->COUNTERTOP = (PWM_MAX_FREQ/frequency);
self->pwm->TASKS_SEQSTART[0] = 1;
}
uint32_t common_hal_pulseio_pwmout_get_frequency(pulseio_pwmout_obj_t* self) {
return self->freq;
}
bool common_hal_pulseio_pwmout_get_variable_frequency(pulseio_pwmout_obj_t* self) {
return self->variable_freq;
}