300 lines
9.1 KiB
C
300 lines
9.1 KiB
C
/*
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* This file is part of the Micro Python project, http://micropython.org/
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2016 Damien P. George
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include <stdio.h>
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#include "driver/ledc.h"
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#include "esp_err.h"
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#include "py/nlr.h"
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#include "py/runtime.h"
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#include "modmachine.h"
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#include "mphalport.h"
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// Forward dec'l
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extern const mp_obj_type_t machine_pwm_type;
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typedef struct _esp32_pwm_obj_t {
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mp_obj_base_t base;
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gpio_num_t pin;
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uint8_t active;
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uint8_t channel;
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} esp32_pwm_obj_t;
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// Which channel has which GPIO pin assigned?
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// (-1 if not assigned)
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STATIC int chan_gpio[LEDC_CHANNEL_MAX];
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// Params for PW operation
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// 5khz
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#define PWFREQ (5000)
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// High speed mode
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#define PWMODE (LEDC_HIGH_SPEED_MODE)
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// 10-bit resolution (compatible with esp8266 PWM)
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#define PWRES (LEDC_TIMER_10_BIT)
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// Timer 1
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#define PWTIMER (LEDC_TIMER_1)
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// Config of timer upon which we run all PWM'ed GPIO pins
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STATIC bool pwm_inited = false;
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STATIC ledc_timer_config_t timer_cfg = {
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.duty_resolution = PWRES,
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.freq_hz = PWFREQ,
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.speed_mode = PWMODE,
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.timer_num = PWTIMER
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};
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STATIC void pwm_init(void) {
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// Initial condition: no channels assigned
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for (int x = 0; x < LEDC_CHANNEL_MAX; ++x) {
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chan_gpio[x] = -1;
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}
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// Init with default timer params
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ledc_timer_config(&timer_cfg);
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}
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STATIC int set_freq(int newval) {
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int ores = timer_cfg.duty_resolution;
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int oval = timer_cfg.freq_hz;
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// Find the highest bit resolution for the requested frequency
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if (newval <= 0) {
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newval = 1;
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}
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unsigned int res = 0;
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for (unsigned int i = LEDC_APB_CLK_HZ / newval; i > 1; i >>= 1, ++res) {
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}
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if (res == 0) {
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res = 1;
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} else if (res > PWRES) {
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// Limit resolution to PWRES to match units of our duty
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res = PWRES;
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}
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// Configure the new resolution and frequency
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timer_cfg.duty_resolution = res;
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timer_cfg.freq_hz = newval;
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if (ledc_timer_config(&timer_cfg) != ESP_OK) {
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timer_cfg.duty_resolution = ores;
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timer_cfg.freq_hz = oval;
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return 0;
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}
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return 1;
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}
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/******************************************************************************/
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// MicroPython bindings for PWM
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STATIC void esp32_pwm_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
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esp32_pwm_obj_t *self = MP_OBJ_TO_PTR(self_in);
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mp_printf(print, "PWM(%u", self->pin);
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if (self->active) {
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mp_printf(print, ", freq=%u, duty=%u", timer_cfg.freq_hz,
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ledc_get_duty(PWMODE, self->channel));
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}
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mp_printf(print, ")");
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}
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STATIC void esp32_pwm_init_helper(esp32_pwm_obj_t *self,
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size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
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enum { ARG_freq, ARG_duty };
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static const mp_arg_t allowed_args[] = {
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{ MP_QSTR_freq, MP_ARG_INT, {.u_int = -1} },
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{ MP_QSTR_duty, MP_ARG_INT, {.u_int = -1} },
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};
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mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
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mp_arg_parse_all(n_args, pos_args, kw_args,
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MP_ARRAY_SIZE(allowed_args), allowed_args, args);
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int channel;
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int avail = -1;
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// Find a free PWM channel, also spot if our pin is
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// already mentioned.
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for (channel = 0; channel < LEDC_CHANNEL_MAX; ++channel) {
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if (chan_gpio[channel] == self->pin) {
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break;
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}
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if ((avail == -1) && (chan_gpio[channel] == -1)) {
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avail = channel;
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}
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}
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if (channel >= LEDC_CHANNEL_MAX) {
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if (avail == -1) {
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mp_raise_ValueError("out of PWM channels");
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}
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channel = avail;
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}
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self->channel = channel;
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// New PWM assignment
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self->active = 1;
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if (chan_gpio[channel] == -1) {
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ledc_channel_config_t cfg = {
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.channel = channel,
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.duty = (1 << timer_cfg.duty_resolution) / 2,
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.gpio_num = self->pin,
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.intr_type = LEDC_INTR_DISABLE,
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.speed_mode = PWMODE,
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.timer_sel = PWTIMER,
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};
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if (ledc_channel_config(&cfg) != ESP_OK) {
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nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError,
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"PWM not supported on pin %d", self->pin));
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}
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chan_gpio[channel] = self->pin;
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}
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// Maybe change PWM timer
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int tval = args[ARG_freq].u_int;
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if (tval != -1) {
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if (tval != timer_cfg.freq_hz) {
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if (!set_freq(tval)) {
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nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError,
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"Bad frequency %d", tval));
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}
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}
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}
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// Set duty cycle?
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int dval = args[ARG_duty].u_int;
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if (dval != -1) {
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dval &= ((1 << PWRES)-1);
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dval >>= PWRES - timer_cfg.duty_resolution;
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ledc_set_duty(PWMODE, channel, dval);
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ledc_update_duty(PWMODE, channel);
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}
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}
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STATIC mp_obj_t esp32_pwm_make_new(const mp_obj_type_t *type,
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size_t n_args, size_t n_kw, const mp_obj_t *args) {
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mp_arg_check_num(n_args, n_kw, 1, MP_OBJ_FUN_ARGS_MAX, true);
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gpio_num_t pin_id = machine_pin_get_id(args[0]);
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// create PWM object from the given pin
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esp32_pwm_obj_t *self = m_new_obj(esp32_pwm_obj_t);
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self->base.type = &machine_pwm_type;
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self->pin = pin_id;
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self->active = 0;
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self->channel = -1;
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// start the PWM subsystem if it's not already running
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if (!pwm_inited) {
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pwm_init();
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pwm_inited = true;
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}
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// start the PWM running for this channel
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mp_map_t kw_args;
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mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);
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esp32_pwm_init_helper(self, n_args - 1, args + 1, &kw_args);
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return MP_OBJ_FROM_PTR(self);
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}
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STATIC mp_obj_t esp32_pwm_init(size_t n_args,
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const mp_obj_t *args, mp_map_t *kw_args) {
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esp32_pwm_init_helper(args[0], n_args - 1, args + 1, kw_args);
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return mp_const_none;
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}
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MP_DEFINE_CONST_FUN_OBJ_KW(esp32_pwm_init_obj, 1, esp32_pwm_init);
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STATIC mp_obj_t esp32_pwm_deinit(mp_obj_t self_in) {
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esp32_pwm_obj_t *self = MP_OBJ_TO_PTR(self_in);
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int chan = self->channel;
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// Valid channel?
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if ((chan >= 0) && (chan < LEDC_CHANNEL_MAX)) {
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// Mark it unused, and tell the hardware to stop routing
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chan_gpio[chan] = -1;
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ledc_stop(PWMODE, chan, 0);
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self->active = 0;
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self->channel = -1;
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gpio_matrix_out(self->pin, SIG_GPIO_OUT_IDX, false, false);
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}
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return mp_const_none;
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}
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STATIC MP_DEFINE_CONST_FUN_OBJ_1(esp32_pwm_deinit_obj, esp32_pwm_deinit);
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STATIC mp_obj_t esp32_pwm_freq(size_t n_args, const mp_obj_t *args) {
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if (n_args == 1) {
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// get
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return MP_OBJ_NEW_SMALL_INT(timer_cfg.freq_hz);
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}
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// set
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int tval = mp_obj_get_int(args[1]);
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if (!set_freq(tval)) {
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nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError,
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"Bad frequency %d", tval));
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}
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return mp_const_none;
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}
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STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(esp32_pwm_freq_obj, 1, 2, esp32_pwm_freq);
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STATIC mp_obj_t esp32_pwm_duty(size_t n_args, const mp_obj_t *args) {
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esp32_pwm_obj_t *self = MP_OBJ_TO_PTR(args[0]);
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int duty;
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if (n_args == 1) {
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// get
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duty = ledc_get_duty(PWMODE, self->channel);
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duty <<= PWRES - timer_cfg.duty_resolution;
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return MP_OBJ_NEW_SMALL_INT(duty);
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}
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// set
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duty = mp_obj_get_int(args[1]);
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duty &= ((1 << PWRES)-1);
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duty >>= PWRES - timer_cfg.duty_resolution;
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ledc_set_duty(PWMODE, self->channel, duty);
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ledc_update_duty(PWMODE, self->channel);
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return mp_const_none;
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}
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STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(esp32_pwm_duty_obj,
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1, 2, esp32_pwm_duty);
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STATIC const mp_rom_map_elem_t esp32_pwm_locals_dict_table[] = {
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{ MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&esp32_pwm_init_obj) },
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{ MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&esp32_pwm_deinit_obj) },
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{ MP_ROM_QSTR(MP_QSTR_freq), MP_ROM_PTR(&esp32_pwm_freq_obj) },
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{ MP_ROM_QSTR(MP_QSTR_duty), MP_ROM_PTR(&esp32_pwm_duty_obj) },
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};
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STATIC MP_DEFINE_CONST_DICT(esp32_pwm_locals_dict,
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esp32_pwm_locals_dict_table);
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const mp_obj_type_t machine_pwm_type = {
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{ &mp_type_type },
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.name = MP_QSTR_PWM,
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.print = esp32_pwm_print,
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.make_new = esp32_pwm_make_new,
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.locals_dict = (mp_obj_dict_t*)&esp32_pwm_locals_dict,
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};
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