diff options
Diffstat (limited to 'ports/esp32/machine_pwm.c')
| -rw-r--r-- | ports/esp32/machine_pwm.c | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/ports/esp32/machine_pwm.c b/ports/esp32/machine_pwm.c new file mode 100644 index 000000000..489833e7c --- /dev/null +++ b/ports/esp32/machine_pwm.c @@ -0,0 +1,277 @@ +/* + * This file is part of the Micro Python project, http://micropython.org/ + * + * The MIT License (MIT) + * + * 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 <stdio.h> +#include "driver/ledc.h" +#include "esp_err.h" + +#include "py/nlr.h" +#include "py/runtime.h" +#include "modmachine.h" +#include "mphalport.h" + +// Forward dec'l +extern const mp_obj_type_t machine_pwm_type; + +typedef struct _esp32_pwm_obj_t { + mp_obj_base_t base; + gpio_num_t pin; + uint8_t active; + uint8_t channel; +} esp32_pwm_obj_t; + +// Which channel has which GPIO pin assigned? +// (-1 if not assigned) +STATIC int chan_gpio[LEDC_CHANNEL_MAX]; + +// Params for PW operation +// 5khz +#define PWFREQ (5000) +// High speed mode +#define PWMODE (LEDC_HIGH_SPEED_MODE) +// 10-bit resolution (compatible with esp8266 PWM) +#define PWRES (LEDC_TIMER_10_BIT) +// Timer 1 +#define PWTIMER (LEDC_TIMER_1) + +// Config of timer upon which we run all PWM'ed GPIO pins +STATIC bool pwm_inited = false; +STATIC ledc_timer_config_t timer_cfg = { + .bit_num = PWRES, + .freq_hz = PWFREQ, + .speed_mode = PWMODE, + .timer_num = PWTIMER +}; + +STATIC void pwm_init(void) { + + // Initial condition: no channels assigned + for (int x = 0; x < LEDC_CHANNEL_MAX; ++x) { + chan_gpio[x] = -1; + } + + // Init with default timer params + ledc_timer_config(&timer_cfg); +} + +STATIC int set_freq(int newval) { + int oval = timer_cfg.freq_hz; + + timer_cfg.freq_hz = newval; + if (ledc_timer_config(&timer_cfg) != ESP_OK) { + timer_cfg.freq_hz = oval; + return 0; + } + return 1; +} + +/******************************************************************************/ + +// MicroPython bindings for PWM + +STATIC void esp32_pwm_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) { + esp32_pwm_obj_t *self = MP_OBJ_TO_PTR(self_in); + mp_printf(print, "PWM(%u", self->pin); + if (self->active) { + mp_printf(print, ", freq=%u, duty=%u", timer_cfg.freq_hz, + ledc_get_duty(PWMODE, self->channel)); + } + mp_printf(print, ")"); +} + +STATIC void esp32_pwm_init_helper(esp32_pwm_obj_t *self, + size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { + enum { ARG_freq, ARG_duty }; + static const mp_arg_t allowed_args[] = { + { MP_QSTR_freq, MP_ARG_INT, {.u_int = -1} }, + { MP_QSTR_duty, MP_ARG_INT, {.u_int = -1} }, + }; + 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); + + int channel; + int avail = -1; + + // Find a free PWM channel, also spot if our pin is + // already mentioned. + for (channel = 0; channel < LEDC_CHANNEL_MAX; ++channel) { + if (chan_gpio[channel] == self->pin) { + break; + } + if ((avail == -1) && (chan_gpio[channel] == -1)) { + avail = channel; + } + } + if (channel >= LEDC_CHANNEL_MAX) { + if (avail == -1) { + mp_raise_ValueError("out of PWM channels"); + } + channel = avail; + } + + // New PWM assignment + self->active = 1; + if (chan_gpio[channel] == -1) { + ledc_channel_config_t cfg = { + .channel = channel, + .duty = (1 << PWRES) / 2, + .gpio_num = self->pin, + .intr_type = LEDC_INTR_DISABLE, + .speed_mode = PWMODE, + .timer_sel = PWTIMER, + }; + if (ledc_channel_config(&cfg) != ESP_OK) { + nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, + "PWM not supported on pin %d", self->pin)); + } + chan_gpio[channel] = self->pin; + self->channel = channel; + } + + // Maybe change PWM timer + int tval = args[ARG_freq].u_int; + if (tval != -1) { + if (tval != timer_cfg.freq_hz) { + if (!set_freq(tval)) { + nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, + "Bad frequency %d", tval)); + } + } + } + + // Set duty cycle? + int dval = args[ARG_duty].u_int; + if (dval != -1) { + dval &= ((1 << PWRES)-1); + ledc_set_duty(PWMODE, channel, dval); + ledc_update_duty(PWMODE, channel); + } +} + +STATIC mp_obj_t esp32_pwm_make_new(const mp_obj_type_t *type, + size_t n_args, size_t n_kw, const mp_obj_t *args) { + mp_arg_check_num(n_args, n_kw, 1, MP_OBJ_FUN_ARGS_MAX, true); + gpio_num_t pin_id = machine_pin_get_id(args[0]); + + // create PWM object from the given pin + esp32_pwm_obj_t *self = m_new_obj(esp32_pwm_obj_t); + self->base.type = &machine_pwm_type; + self->pin = pin_id; + self->active = 0; + self->channel = -1; + + // start the PWM subsystem if it's not already running + if (!pwm_inited) { + pwm_init(); + pwm_inited = true; + } + + // start the PWM running for this channel + mp_map_t kw_args; + mp_map_init_fixed_table(&kw_args, n_kw, args + n_args); + esp32_pwm_init_helper(self, n_args - 1, args + 1, &kw_args); + + return MP_OBJ_FROM_PTR(self); +} + +STATIC mp_obj_t esp32_pwm_init(size_t n_args, + const mp_obj_t *args, mp_map_t *kw_args) { + esp32_pwm_init_helper(args[0], n_args - 1, args + 1, kw_args); + return mp_const_none; +} +MP_DEFINE_CONST_FUN_OBJ_KW(esp32_pwm_init_obj, 1, esp32_pwm_init); + +STATIC mp_obj_t esp32_pwm_deinit(mp_obj_t self_in) { + esp32_pwm_obj_t *self = MP_OBJ_TO_PTR(self_in); + int chan = self->channel; + + // Valid channel? + if ((chan >= 0) && (chan < LEDC_CHANNEL_MAX)) { + // Mark it unused, and tell the hardware to stop routing + chan_gpio[chan] = -1; + ledc_stop(PWMODE, chan, 0); + self->active = 0; + self->channel = -1; + } + return mp_const_none; +} +STATIC MP_DEFINE_CONST_FUN_OBJ_1(esp32_pwm_deinit_obj, esp32_pwm_deinit); + +STATIC mp_obj_t esp32_pwm_freq(size_t n_args, const mp_obj_t *args) { + if (n_args == 1) { + // get + return MP_OBJ_NEW_SMALL_INT(timer_cfg.freq_hz); + } + + // set + int tval = mp_obj_get_int(args[1]); + if (!set_freq(tval)) { + nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, + "Bad frequency %d", tval)); + } + return mp_const_none; +} + +STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(esp32_pwm_freq_obj, 1, 2, esp32_pwm_freq); + +STATIC mp_obj_t esp32_pwm_duty(size_t n_args, const mp_obj_t *args) { + esp32_pwm_obj_t *self = MP_OBJ_TO_PTR(args[0]); + int duty; + + if (n_args == 1) { + // get + duty = ledc_get_duty(PWMODE, self->channel); + return MP_OBJ_NEW_SMALL_INT(duty); + } + + // set + duty = mp_obj_get_int(args[1]); + duty &= ((1 << PWRES)-1); + ledc_set_duty(PWMODE, self->channel, duty); + ledc_update_duty(PWMODE, self->channel); + + return mp_const_none; +} +STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(esp32_pwm_duty_obj, + 1, 2, esp32_pwm_duty); + +STATIC const mp_rom_map_elem_t esp32_pwm_locals_dict_table[] = { + { MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&esp32_pwm_init_obj) }, + { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&esp32_pwm_deinit_obj) }, + { MP_ROM_QSTR(MP_QSTR_freq), MP_ROM_PTR(&esp32_pwm_freq_obj) }, + { MP_ROM_QSTR(MP_QSTR_duty), MP_ROM_PTR(&esp32_pwm_duty_obj) }, +}; + +STATIC MP_DEFINE_CONST_DICT(esp32_pwm_locals_dict, + esp32_pwm_locals_dict_table); + +const mp_obj_type_t machine_pwm_type = { + { &mp_type_type }, + .name = MP_QSTR_PWM, + .print = esp32_pwm_print, + .make_new = esp32_pwm_make_new, + .locals_dict = (mp_obj_dict_t*)&esp32_pwm_locals_dict, +}; |