circuitpython/ports/nrf/modules/machine/pwm.c
robert-hh ed1f42cb49 nrf/modules/machine/pwm: Support using all 4 channels of a PWM module.
These have the same frequency, but can have different duty cycle and
polarity.

pwm.deinit() stops all channels of a module, but does not release the
module.  pwm.init() without arguments restarts all outputs.
2023-03-10 10:44:02 +11:00

400 lines
15 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2016-2018 Glenn Ruben Bakke
* Copyright (c) 2023 Robert Hammelrath
*
* 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 <stdio.h>
#include <string.h>
#include "py/nlr.h"
#include "py/runtime.h"
#include "py/mphal.h"
#if MICROPY_PY_MACHINE_HW_PWM
#include "pin.h"
#include "genhdr/pins.h"
#include "pwm.h"
#if defined(NRF52_SERIES)
// Use PWM hardware.
#include "nrfx_pwm.h"
#endif
#define PWM_MAX_BASE_FREQ (16000000)
#define PWM_MIN_BASE_FREQ (125000)
#define PWM_MAX_PERIOD (32768)
typedef enum {
MODE_HIGH_LOW = 0,
MODE_LOW_HIGH
} pwm_mode_t;
typedef enum {
DUTY_NOT_SET = 0,
DUTY_PERCENT,
DUTY_U16,
DUTY_NS
} pwm_duty_t;
typedef enum {
FREE = 0,
STOPPED,
RUNNING
} pwm_run_t;
typedef struct {
uint8_t pwm_pin[NRF_PWM_CHANNEL_COUNT];
pwm_mode_t mode[NRF_PWM_CHANNEL_COUNT];
pwm_duty_t duty_mode[NRF_PWM_CHANNEL_COUNT];
uint32_t duty[NRF_PWM_CHANNEL_COUNT];
pwm_run_t active;
bool defer_start;
int8_t freq_div;
uint32_t freq;
} machine_pwm_config_t;
typedef struct _machine_pwm_obj_t {
mp_obj_base_t base;
const nrfx_pwm_t *p_pwm;
machine_pwm_config_t *p_config;
uint8_t id;
uint8_t channel;
} machine_pwm_obj_t;
STATIC const nrfx_pwm_t machine_hard_pwm_instances[] = {
#if defined(NRF52_SERIES)
NRFX_PWM_INSTANCE(0),
NRFX_PWM_INSTANCE(1),
NRFX_PWM_INSTANCE(2),
#if NRF52840
NRFX_PWM_INSTANCE(3),
#endif
#endif
};
STATIC machine_pwm_config_t hard_configs[MP_ARRAY_SIZE(machine_hard_pwm_instances)];
STATIC const machine_pwm_obj_t machine_hard_pwm_obj[] = {
#if defined(NRF52_SERIES)
{{&machine_pwm_type}, .p_pwm = &machine_hard_pwm_instances[0], .p_config = &hard_configs[0], 0, 0},
{{&machine_pwm_type}, .p_pwm = &machine_hard_pwm_instances[0], .p_config = &hard_configs[0], 0, 1},
{{&machine_pwm_type}, .p_pwm = &machine_hard_pwm_instances[0], .p_config = &hard_configs[0], 0, 2},
{{&machine_pwm_type}, .p_pwm = &machine_hard_pwm_instances[0], .p_config = &hard_configs[0], 0, 3},
{{&machine_pwm_type}, .p_pwm = &machine_hard_pwm_instances[1], .p_config = &hard_configs[1], 1, 0},
{{&machine_pwm_type}, .p_pwm = &machine_hard_pwm_instances[1], .p_config = &hard_configs[1], 1, 1},
{{&machine_pwm_type}, .p_pwm = &machine_hard_pwm_instances[1], .p_config = &hard_configs[1], 1, 2},
{{&machine_pwm_type}, .p_pwm = &machine_hard_pwm_instances[1], .p_config = &hard_configs[1], 1, 3},
{{&machine_pwm_type}, .p_pwm = &machine_hard_pwm_instances[2], .p_config = &hard_configs[2], 2, 0},
{{&machine_pwm_type}, .p_pwm = &machine_hard_pwm_instances[2], .p_config = &hard_configs[2], 2, 1},
{{&machine_pwm_type}, .p_pwm = &machine_hard_pwm_instances[2], .p_config = &hard_configs[2], 2, 2},
{{&machine_pwm_type}, .p_pwm = &machine_hard_pwm_instances[2], .p_config = &hard_configs[2], 2, 3},
#if NRF52840
{{&machine_pwm_type}, .p_pwm = &machine_hard_pwm_instances[3], .p_config = &hard_configs[3], 3, 0},
{{&machine_pwm_type}, .p_pwm = &machine_hard_pwm_instances[3], .p_config = &hard_configs[3], 3, 1},
{{&machine_pwm_type}, .p_pwm = &machine_hard_pwm_instances[3], .p_config = &hard_configs[3], 3, 2},
{{&machine_pwm_type}, .p_pwm = &machine_hard_pwm_instances[3], .p_config = &hard_configs[3], 3, 3},
#endif
#endif
};
void pwm_init0(void) {
for (int i = 0; i < MP_ARRAY_SIZE(hard_configs); i++) {
hard_configs[i].active = FREE;
hard_configs[i].freq_div = -1;
hard_configs[i].freq = 0;
memset(hard_configs[i].duty_mode, DUTY_NOT_SET, NRF_PWM_CHANNEL_COUNT);
}
}
// Find a free PWM object
STATIC int hard_pwm_find() {
// look for a free module.
for (int j = 0; j < MP_ARRAY_SIZE(hard_configs); j++) {
if (hard_configs[j].active == FREE) {
return j * NRF_PWM_CHANNEL_COUNT;
}
}
mp_raise_ValueError(MP_ERROR_TEXT("no free PWM object"));
}
STATIC void mp_machine_pwm_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
machine_pwm_obj_t *self = self_in;
static char *duty_suffix[] = { "", "", "_u16", "_ns" };
mp_printf(print, "<PWM: Pin=%u freq=%dHz duty%s=%d invert=%d id=%u channel=%u>",
self->p_config->pwm_pin[self->channel], self->p_config->freq,
duty_suffix[self->p_config->duty_mode[self->channel]], self->p_config->duty[self->channel],
self->p_config->mode[self->channel], self->id, self->channel);
}
/******************************************************************************/
/* MicroPython bindings for machine API */
STATIC void machine_hard_pwm_start(const machine_pwm_obj_t *self);
STATIC void mp_machine_pwm_deinit(const machine_pwm_obj_t *self);
STATIC void mp_machine_pwm_freq_set(const machine_pwm_obj_t *self, mp_int_t freq);
STATIC void mp_machine_pwm_duty_set(const machine_pwm_obj_t *self, mp_int_t duty);
STATIC void mp_machine_pwm_duty_set_u16(const machine_pwm_obj_t *self, mp_int_t duty_u16);
STATIC void mp_machine_pwm_duty_set_ns(const machine_pwm_obj_t *self, mp_int_t duty_ns);
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_pin, MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_freq, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_duty, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_duty_u16, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_duty_ns, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_invert, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_id, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_channel, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
};
STATIC void mp_machine_pwm_init_helper(const machine_pwm_obj_t *self, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_pin, ARG_freq, ARG_duty, ARG_duty_u16, ARG_duty_ns, ARG_invert, ARG_id, ARG_channel };
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
self->p_config->defer_start = true;
if (args[ARG_freq].u_int != -1) {
mp_machine_pwm_freq_set(self, args[ARG_freq].u_int);
}
if (args[ARG_duty].u_int != -1) {
mp_machine_pwm_duty_set(self, args[ARG_duty].u_int);
}
if (args[ARG_duty_u16].u_int != -1) {
mp_machine_pwm_duty_set_u16(self, args[ARG_duty_u16].u_int);
}
if (args[ARG_duty_ns].u_int != -1) {
mp_machine_pwm_duty_set_ns(self, args[ARG_duty_ns].u_int);
}
if (args[ARG_invert].u_int != -1) {
self->p_config->mode[self->channel] = args[ARG_invert].u_int ? MODE_LOW_HIGH : MODE_HIGH_LOW;
}
self->p_config->defer_start = false;
machine_hard_pwm_start(self);
}
STATIC mp_obj_t mp_machine_pwm_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
enum { ARG_pin, ARG_freq, ARG_duty, ARG_duty_u16, ARG_duty_ns, ARG_invert, ARG_id, ARG_channel };
// parse args
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
// check if the PWM pin is given.
int pwm_pin;
if (args[ARG_pin].u_obj != MP_OBJ_NULL) {
pwm_pin = mp_hal_get_pin_obj(args[ARG_pin].u_obj)->pin;
} else {
mp_raise_ValueError(MP_ERROR_TEXT("Pin missing"));
}
// Get the PWM object number
// If just the ID is given, use channel 0
// If none is given, attempt to find an unused object.
int pwm_id = -1;
if (args[ARG_id].u_int != -1) {
if (args[ARG_id].u_int >= 0 && args[ARG_id].u_int < MP_ARRAY_SIZE(machine_hard_pwm_instances)) {
pwm_id = args[ARG_id].u_int * NRF_PWM_CHANNEL_COUNT;
if (args[ARG_channel].u_int != -1) {
if (args[ARG_channel].u_int >= 0 && args[ARG_channel].u_int < NRF_PWM_CHANNEL_COUNT) {
pwm_id += args[ARG_channel].u_int;
}
}
}
} else {
// no ID given, search for a free ID.
pwm_id = hard_pwm_find();
}
if (pwm_id < 0) {
mp_raise_ValueError(MP_ERROR_TEXT("invalid PWM id"));
}
const machine_pwm_obj_t *self = &machine_hard_pwm_obj[pwm_id];
int pwm_channel = pwm_id % NRF_PWM_CHANNEL_COUNT;
self->p_config->pwm_pin[pwm_channel] = pwm_pin;
self->p_config->duty_mode[pwm_channel] = DUTY_NOT_SET;
self->p_config->duty[pwm_channel] = 0;
self->p_config->mode[pwm_channel] = MODE_HIGH_LOW;
self->p_config->defer_start = false;
// start the PWM running for this channel
mp_map_t kw_args;
mp_map_init_fixed_table(&kw_args, n_kw, all_args + n_args);
mp_machine_pwm_init_helper(self, n_args, all_args, &kw_args);
return MP_OBJ_FROM_PTR(self);
}
// Stop all PWM modules and release them
void pwm_deinit_all(void) {
for (int i = 0; i < MP_ARRAY_SIZE(machine_hard_pwm_instances); i++) {
mp_machine_pwm_deinit(&machine_hard_pwm_obj[i * NRF_PWM_CHANNEL_COUNT]);
}
pwm_init0();
}
// Stop the PWM module, but do not release it.
STATIC void mp_machine_pwm_deinit(const machine_pwm_obj_t *self) {
self->p_config->active = STOPPED;
nrfx_pwm_stop(self->p_pwm, true);
nrfx_pwm_uninit(self->p_pwm);
}
STATIC mp_obj_t mp_machine_pwm_freq_get(const machine_pwm_obj_t *self) {
return MP_OBJ_NEW_SMALL_INT(self->p_config->freq);
}
STATIC void mp_machine_pwm_freq_set(const machine_pwm_obj_t *self, mp_int_t freq) {
uint8_t div = 0;
if (freq > (PWM_MAX_BASE_FREQ / 3) || freq <= (PWM_MIN_BASE_FREQ / PWM_MAX_PERIOD)) {
mp_raise_ValueError(MP_ERROR_TEXT("frequency out of range"));
}
for (div = 0; div < 8; div++) {
if (PWM_MAX_BASE_FREQ / (1 << div) / freq < PWM_MAX_PERIOD) {
break;
}
}
self->p_config->freq_div = div;
self->p_config->freq = freq;
machine_hard_pwm_start(self);
}
STATIC mp_obj_t mp_machine_pwm_duty_get(const machine_pwm_obj_t *self) {
if (self->p_config->duty_mode[self->channel] == DUTY_PERCENT) {
return MP_OBJ_NEW_SMALL_INT(self->p_config->duty[self->channel]);
} else if (self->p_config->duty_mode[self->channel] == DUTY_U16) {
return MP_OBJ_NEW_SMALL_INT(self->p_config->duty[self->channel] * 100 / 65536);
} else {
return MP_OBJ_NEW_SMALL_INT(-1);
}
}
STATIC void mp_machine_pwm_duty_set(const machine_pwm_obj_t *self, mp_int_t duty) {
self->p_config->duty[self->channel] = duty;
self->p_config->duty_mode[self->channel] = DUTY_PERCENT;
machine_hard_pwm_start(self);
}
STATIC mp_obj_t mp_machine_pwm_duty_get_u16(const machine_pwm_obj_t *self) {
if (self->p_config->duty_mode[self->channel] == DUTY_U16) {
return MP_OBJ_NEW_SMALL_INT(self->p_config->duty[self->channel]);
} else if (self->p_config->duty_mode[self->channel] == DUTY_PERCENT) {
return MP_OBJ_NEW_SMALL_INT(self->p_config->duty[self->channel] * 65536 / 100);
} else {
return MP_OBJ_NEW_SMALL_INT(-1);
}
}
STATIC void mp_machine_pwm_duty_set_u16(const machine_pwm_obj_t *self, mp_int_t duty) {
self->p_config->duty[self->channel] = duty;
self->p_config->duty_mode[self->channel] = DUTY_U16;
machine_hard_pwm_start(self);
}
STATIC mp_obj_t mp_machine_pwm_duty_get_ns(const machine_pwm_obj_t *self) {
if (self->p_config->duty_mode[self->channel] == DUTY_NS) {
return MP_OBJ_NEW_SMALL_INT(self->p_config->duty[self->channel]);
} else {
return MP_OBJ_NEW_SMALL_INT(-1);
}
}
STATIC void mp_machine_pwm_duty_set_ns(const machine_pwm_obj_t *self, mp_int_t duty) {
self->p_config->duty[self->channel] = duty;
self->p_config->duty_mode[self->channel] = DUTY_NS;
machine_hard_pwm_start(self);
}
/* code for hard implementation ***********************************************/
STATIC void machine_hard_pwm_start(const machine_pwm_obj_t *self) {
nrfx_pwm_config_t config;
// check if ready to go
if (self->p_config->defer_start == true || self->p_config->freq_div < 0 || self->p_config->duty_mode[self->channel] == DUTY_NOT_SET) {
return; // Not ready yet.
}
self->p_config->active = RUNNING;
config.output_pins[0] = self->p_config->duty_mode[0] != DUTY_NOT_SET ? self->p_config->pwm_pin[0] : NRFX_PWM_PIN_NOT_USED;
config.output_pins[1] = self->p_config->duty_mode[1] != DUTY_NOT_SET ? self->p_config->pwm_pin[1] : NRFX_PWM_PIN_NOT_USED;
config.output_pins[2] = self->p_config->duty_mode[2] != DUTY_NOT_SET ? self->p_config->pwm_pin[2] : NRFX_PWM_PIN_NOT_USED;
config.output_pins[3] = self->p_config->duty_mode[3] != DUTY_NOT_SET ? self->p_config->pwm_pin[3] : NRFX_PWM_PIN_NOT_USED;
uint32_t tick_freq = PWM_MAX_BASE_FREQ / (1 << self->p_config->freq_div);
uint32_t period = tick_freq / self->p_config->freq;
config.irq_priority = 6;
config.base_clock = self->p_config->freq_div;
config.count_mode = NRF_PWM_MODE_UP;
config.top_value = period;
config.load_mode = NRF_PWM_LOAD_INDIVIDUAL;
config.step_mode = NRF_PWM_STEP_AUTO;
nrfx_pwm_stop(self->p_pwm, true);
nrfx_pwm_uninit(self->p_pwm);
nrfx_pwm_init(self->p_pwm, &config, NULL, NULL);
volatile static uint16_t pwm_seq[4];
for (int i = 0; i < NRF_PWM_CHANNEL_COUNT; i++) {
uint16_t pulse_width = 0;
if (self->p_config->duty_mode[i] == DUTY_PERCENT) {
pulse_width = ((period * self->p_config->duty[i]) / 100);
} else if (self->p_config->duty_mode[i] == DUTY_U16) {
pulse_width = ((period * self->p_config->duty[i]) / 65536);
}
if (self->p_config->duty_mode[i] == DUTY_NS) {
pulse_width = (uint64_t)self->p_config->duty[i] * tick_freq / 1000000000ULL;
}
if (self->p_config->mode[i] == MODE_HIGH_LOW) {
pwm_seq[i] = 0x8000 | pulse_width;
} else {
pwm_seq[i] = pulse_width;
}
}
const nrf_pwm_sequence_t pwm_sequence = {
.values.p_raw = (const uint16_t *)&pwm_seq,
.length = 4,
.repeats = 0,
.end_delay = 0
};
nrfx_pwm_simple_playback(self->p_pwm,
&pwm_sequence,
0, // Loop disabled.
0);
}
#endif // MICROPY_PY_MACHINE_HW_PWM