circuitpython/ports/raspberrypi/common-hal/pulseio/PulseOut.c

134 lines
4.7 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2021 Dave Putz for Adafruit Industries
*
* 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 "common-hal/pulseio/PulseOut.h"
#include <stdint.h>
#include "mpconfigport.h"
#include "py/runtime.h"
#include "shared-bindings/pulseio/PulseOut.h"
#include "shared-bindings/pwmio/PWMOut.h"
#include "shared-bindings/microcontroller/__init__.h"
#include "common-hal/pwmio/PWMOut.h"
#include "src/rp2040/hardware_structs/include/hardware/structs/pwm.h"
#include "src/rp2_common/hardware_gpio/include/hardware/gpio.h"
#include "src/rp2_common/hardware_pwm/include/hardware/pwm.h"
#include "src/common/pico_time/include/pico/time.h"
volatile alarm_id_t cur_alarm = 0;
static void pulse_finish(pulseio_pulseout_obj_t *self) {
self->pulse_index++;
// Turn pwm pin off by switching the GPIO mux to SIO (the cpu manual
// control).
if (self->pulse_index >= self->pulse_length) {
gpio_set_function(self->pin, GPIO_FUNC_SIO);
return;
}
if (self->pulse_index % 2 == 0) {
gpio_set_function(self->pin, GPIO_FUNC_PWM);
} else {
gpio_set_function(self->pin, GPIO_FUNC_SIO);
}
uint64_t delay = self->pulse_buffer[self->pulse_index];
if (delay < self->min_pulse) {
delay = self->min_pulse;
}
cur_alarm = 0;
// if the alarm cannot be set, try again with a longer delay
while (cur_alarm == 0) {
cur_alarm = add_alarm_in_us(delay, pulseout_interrupt_handler, self, false);
delay = delay + 1;
}
}
int64_t pulseout_interrupt_handler(alarm_id_t id, void *user_data) {
pulse_finish(user_data);
return 0;
}
void pulseout_reset() {
}
void common_hal_pulseio_pulseout_construct(pulseio_pulseout_obj_t *self,
const mcu_pin_obj_t *pin,
uint32_t frequency,
uint16_t duty_cycle) {
pwmout_result_t result = common_hal_pwmio_pwmout_construct(
&self->carrier, pin, 0, frequency, false);
// This will raise an exception and not return if needed.
common_hal_pwmio_pwmout_raise_error(result);
// Disable gpio output before we set the duty cycle.
gpio_put(pin->number, false);
gpio_set_dir(pin->number, GPIO_OUT);
gpio_set_function(pin->number, GPIO_FUNC_SIO);
common_hal_pwmio_pwmout_set_duty_cycle(&self->carrier, duty_cycle);
self->pin = pin->number;
self->slice = self->carrier.slice;
self->min_pulse = (1000000 / self->carrier.actual_frequency);
}
bool common_hal_pulseio_pulseout_deinited(pulseio_pulseout_obj_t *self) {
return self->pin == NO_PIN;
}
void common_hal_pulseio_pulseout_deinit(pulseio_pulseout_obj_t *self) {
if (common_hal_pulseio_pulseout_deinited(self)) {
return;
}
gpio_set_dir(self->pin, GPIO_IN);
common_hal_pwmio_pwmout_deinit(&self->carrier);
self->pin = NO_PIN;
}
void common_hal_pulseio_pulseout_send(pulseio_pulseout_obj_t *self, uint16_t *pulses, uint16_t length) {
self->pulse_buffer = pulses;
self->pulse_index = 0;
self->pulse_length = length;
// Turn on the signal by connecting the PWM to the outside pin.
gpio_set_function(self->pin, GPIO_FUNC_PWM);
uint64_t delay = self->pulse_buffer[0];
if (delay < self->min_pulse) {
delay = self->min_pulse;
}
cur_alarm = 0;
// if the alarm cannot be set, try again with a longer delay
while (cur_alarm == 0) {
cur_alarm = add_alarm_in_us(delay, pulseout_interrupt_handler, self, false);
delay = delay + 1;
}
while (self->pulse_index < length) {
// Do other things while we wait. The interrupts will handle sending the
// signal.
RUN_BACKGROUND_TASKS;
}
}