262 lines
7.6 KiB
C
262 lines
7.6 KiB
C
/*
|
|
* This file is part of the MicroPython project, http://micropython.org/
|
|
*
|
|
* The MIT License (MIT)
|
|
*
|
|
* Copyright (c) 2016 Mark Shannon
|
|
*
|
|
* 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 "py/mphal.h"
|
|
|
|
#if MICROPY_PY_MACHINE_SOFT_PWM
|
|
|
|
#include "stddef.h"
|
|
#include "py/runtime.h"
|
|
#include "py/gc.h"
|
|
#include "nrf_timer.h"
|
|
#include "nrf_gpio.h"
|
|
#include "pin.h"
|
|
|
|
#include "ticker.h"
|
|
|
|
#define CYCLES_PER_MICROSECONDS 16
|
|
|
|
#define MICROSECONDS_PER_TICK 16
|
|
#define CYCLES_PER_TICK (CYCLES_PER_MICROSECONDS*MICROSECONDS_PER_TICK)
|
|
// This must be an integer multiple of MICROSECONDS_PER_TICK
|
|
#define MICROSECONDS_PER_MACRO_TICK 6000
|
|
#define MILLISECONDS_PER_MACRO_TICK 6
|
|
|
|
#define PWM_TICKER_INDEX 2
|
|
|
|
// Default period of 20ms
|
|
#define DEFAULT_PERIOD ((20*1000)/MICROSECONDS_PER_TICK)
|
|
|
|
typedef struct _pwm_event {
|
|
uint16_t time;
|
|
uint8_t pin;
|
|
uint8_t turn_on;
|
|
} pwm_event;
|
|
|
|
typedef struct _pwm_events {
|
|
uint8_t count;
|
|
uint16_t period;
|
|
uint32_t all_pins;
|
|
pwm_event events[1];
|
|
} pwm_events;
|
|
|
|
static const pwm_events OFF_EVENTS = {
|
|
.count = 1,
|
|
.period = DEFAULT_PERIOD,
|
|
.all_pins = 0,
|
|
.events = {
|
|
{
|
|
.time = 1024,
|
|
.pin = 31,
|
|
.turn_on = 0
|
|
}
|
|
}
|
|
};
|
|
|
|
#define active_events MP_STATE_PORT(pwm_active_events)
|
|
#define pending_events MP_STATE_PORT(pwm_pending_events)
|
|
|
|
void softpwm_init0(void) {
|
|
active_events = &OFF_EVENTS;
|
|
pending_events = NULL;
|
|
}
|
|
|
|
static uint8_t next_event = 0;
|
|
|
|
static inline int32_t pwm_get_period_ticks(void) {
|
|
const pwm_events *tmp = pending_events;
|
|
if (tmp == NULL)
|
|
tmp = active_events;
|
|
return tmp->period;
|
|
}
|
|
|
|
#if 0
|
|
void pwm_dump_events(const pwm_events *events) {
|
|
printf("Count %d, period %d, all pins %d\r\n", events->count, events->period, events->all_pins);
|
|
for (uint32_t i = 0; i < events->count; i++) {
|
|
const pwm_event *event = &events->events[i];
|
|
printf("Event. pin: %d, duty cycle: %d, turn_on: %d\r\n",
|
|
event->pin, event->time, event->turn_on);
|
|
}
|
|
}
|
|
|
|
void pwm_dump_state(void) {
|
|
while(pending_events);
|
|
pwm_dump_events(active_events);
|
|
}
|
|
#endif
|
|
|
|
static const pwm_events *swap_pending(const pwm_events *in) {
|
|
__disable_irq();
|
|
const pwm_events *result = pending_events;
|
|
pending_events = in;
|
|
__enable_irq();
|
|
return result;
|
|
}
|
|
|
|
static pwm_events *copy_events(const pwm_events *orig, uint32_t count) {
|
|
pwm_events *events = m_malloc(sizeof(pwm_events) + (count-1)*sizeof(pwm_event));
|
|
events->count = count;
|
|
uint32_t copy = count > orig->count ? orig->count : count;
|
|
for (uint32_t i = 0; i < copy; i++) {
|
|
events->events[i] = orig->events[i];
|
|
}
|
|
return events;
|
|
}
|
|
|
|
static int find_pin_in_events(const pwm_events *events, uint32_t pin) {
|
|
for (int i = 0; i < events->count; i++) {
|
|
if (events->events[i].pin == pin)
|
|
return i;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
static void sort_events(pwm_events *events) {
|
|
// Insertion sort
|
|
for (int32_t i = 1; i < events->count; i++) {
|
|
pwm_event x = events->events[i];
|
|
int32_t j;
|
|
for (j = i - 1; j >= 0 && events->events[j].time > x.time; j--) {
|
|
events->events[j+1] = events->events[j];
|
|
}
|
|
events->events[j+1] = x;
|
|
}
|
|
}
|
|
|
|
int32_t pwm_callback(void) {
|
|
int32_t tdiff;
|
|
const pwm_events *events = active_events;
|
|
const pwm_event *event = &events->events[next_event];
|
|
int32_t tnow = (event->time*events->period)>>10;
|
|
do {
|
|
if (event->turn_on) {
|
|
nrf_gpio_pin_set(event->pin);
|
|
next_event++;
|
|
} else {
|
|
// TODO: Resolve port for nrf52
|
|
nrf_gpio_port_out_clear(NRF_GPIO, events->all_pins);
|
|
next_event = 0;
|
|
tnow = 0;
|
|
if (pending_events) {
|
|
events = pending_events;
|
|
active_events = events;
|
|
pending_events = NULL;
|
|
}
|
|
}
|
|
event = &events->events[next_event];
|
|
tdiff = ((event->time*events->period)>>10) - tnow;
|
|
} while (tdiff == 0);
|
|
return tdiff;
|
|
}
|
|
|
|
void pwm_start(void) {
|
|
set_ticker_callback(PWM_TICKER_INDEX, pwm_callback, 120);
|
|
}
|
|
|
|
void pwm_stop(void) {
|
|
clear_ticker_callback(PWM_TICKER_INDEX);
|
|
}
|
|
|
|
static void pwm_set_period_ticks(int32_t ticks) {
|
|
const pwm_events *old_events = swap_pending(NULL);
|
|
if (old_events == NULL) {
|
|
old_events = active_events;
|
|
}
|
|
pwm_events *events = copy_events(old_events, old_events->count);
|
|
events->all_pins = old_events->all_pins;
|
|
events->period = ticks;
|
|
pending_events = events;
|
|
}
|
|
|
|
int pwm_set_period_us(int32_t us) {
|
|
if ((us < 256) ||
|
|
(us > 1000000)) {
|
|
return -1;
|
|
}
|
|
pwm_set_period_ticks(us/MICROSECONDS_PER_TICK);
|
|
return 0;
|
|
}
|
|
|
|
int32_t pwm_get_period_us(void) {
|
|
return pwm_get_period_ticks()*MICROSECONDS_PER_TICK;
|
|
}
|
|
|
|
void pwm_set_duty_cycle(int32_t pin, uint32_t value) {
|
|
if (value >= (1<<10)) {
|
|
value = (1<<10)-1;
|
|
}
|
|
uint32_t turn_on_time = 1024-value;
|
|
const pwm_events *old_events = swap_pending(NULL);
|
|
if (old_events == NULL) {
|
|
old_events = active_events;
|
|
}
|
|
if (((1<<pin)&old_events->all_pins) == 0) {
|
|
nrf_gpio_cfg_output(pin);
|
|
}
|
|
int ev = find_pin_in_events(old_events, pin);
|
|
pwm_events *events;
|
|
if (ev < 0 && value == 0) {
|
|
return;
|
|
} else if (ev < 0) {
|
|
events = copy_events(old_events, old_events->count+1);
|
|
events->all_pins = old_events->all_pins | (1<<pin);
|
|
events->events[old_events->count].time = turn_on_time;
|
|
events->events[old_events->count].pin = pin;
|
|
events->events[old_events->count].turn_on = 1;
|
|
} else if (value == 0) {
|
|
events = copy_events(old_events, old_events->count-1);
|
|
events->all_pins = old_events->all_pins & ~(1<<pin);
|
|
if (ev < old_events->count-1) {
|
|
events->events[ev] = old_events->events[old_events->count-1];
|
|
}
|
|
} else {
|
|
events = copy_events(old_events, old_events->count);
|
|
events->all_pins = old_events->all_pins;
|
|
events->events[ev].time = turn_on_time;
|
|
}
|
|
events->period = old_events->period;
|
|
sort_events(events);
|
|
pending_events = events;
|
|
return;
|
|
}
|
|
|
|
void pwm_release(int32_t pin) {
|
|
pwm_set_duty_cycle(pin, 0);
|
|
const pwm_events *ev = active_events;
|
|
int i = find_pin_in_events(ev, pin);
|
|
if (i < 0)
|
|
return;
|
|
// If i >= 0 it means that `ev` is in RAM, so it safe to discard the const qualifier
|
|
((pwm_events *)ev)->events[i].pin = 31;
|
|
nrf_gpio_pin_clear(pin);
|
|
}
|
|
|
|
MP_REGISTER_ROOT_POINTER(const struct _pwm_events *pwm_active_events);
|
|
MP_REGISTER_ROOT_POINTER(const struct _pwm_events *pwm_pending_events);
|
|
|
|
#endif // MICROPY_PY_MACHINE_SOFT_PWM
|