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| 1 | +/* |
| 2 | + * This file is part of the Micro Python project, http://micropython.org/ |
| 3 | + * |
| 4 | + * The MIT License (MIT) |
| 5 | + * |
| 6 | + * Copyright (c) 2016 Damien P. George |
| 7 | + * |
| 8 | + * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 9 | + * of this software and associated documentation files (the "Software"), to deal |
| 10 | + * in the Software without restriction, including without limitation the rights |
| 11 | + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 12 | + * copies of the Software, and to permit persons to whom the Software is |
| 13 | + * furnished to do so, subject to the following conditions: |
| 14 | + * |
| 15 | + * The above copyright notice and this permission notice shall be included in |
| 16 | + * all copies or substantial portions of the Software. |
| 17 | + * |
| 18 | + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 19 | + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 20 | + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 21 | + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 22 | + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 23 | + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| 24 | + * THE SOFTWARE. |
| 25 | + */ |
| 26 | +#include <stdio.h> |
| 27 | +#include "driver/ledc.h" |
| 28 | +#include "esp_err.h" |
| 29 | + |
| 30 | +#include "py/nlr.h" |
| 31 | +#include "py/runtime.h" |
| 32 | +#include "modmachine.h" |
| 33 | +#include "mphalport.h" |
| 34 | + |
| 35 | +// Forward dec'l |
| 36 | +extern const mp_obj_type_t machine_pwm_type; |
| 37 | + |
| 38 | +typedef struct _esp32_pwm_obj_t { |
| 39 | + mp_obj_base_t base; |
| 40 | + gpio_num_t pin; |
| 41 | + uint8_t active; |
| 42 | + uint8_t channel; |
| 43 | +} esp32_pwm_obj_t; |
| 44 | + |
| 45 | +// Which channel has which GPIO pin assigned? |
| 46 | +// (-1 if not assigned) |
| 47 | +STATIC int chan_gpio[LEDC_CHANNEL_MAX]; |
| 48 | + |
| 49 | +// Params for PW operation |
| 50 | +// 5khz |
| 51 | +#define PWFREQ (5000) |
| 52 | +// High speed mode |
| 53 | +#define PWMODE (LEDC_HIGH_SPEED_MODE) |
| 54 | +// 10-bit resolution (compatible with esp8266 PWM) |
| 55 | +#define PWRES (LEDC_TIMER_10_BIT) |
| 56 | +// Timer 1 |
| 57 | +#define PWTIMER (LEDC_TIMER_1) |
| 58 | + |
| 59 | +// Config of timer upon which we run all PWM'ed GPIO pins |
| 60 | +STATIC bool pwm_inited = false; |
| 61 | +STATIC ledc_timer_config_t timer_cfg = { |
| 62 | + .bit_num = PWRES, |
| 63 | + .freq_hz = PWFREQ, |
| 64 | + .speed_mode = PWMODE, |
| 65 | + .timer_num = PWTIMER |
| 66 | +}; |
| 67 | + |
| 68 | +STATIC void pwm_init(void) { |
| 69 | + |
| 70 | + // Initial condition: no channels assigned |
| 71 | + for (int x = 0; x < LEDC_CHANNEL_MAX; ++x) { |
| 72 | + chan_gpio[x] = -1; |
| 73 | + } |
| 74 | + |
| 75 | + // Init with default timer params |
| 76 | + ledc_timer_config(&timer_cfg); |
| 77 | +} |
| 78 | + |
| 79 | +STATIC int set_freq(int newval) { |
| 80 | + int oval = timer_cfg.freq_hz; |
| 81 | + |
| 82 | + timer_cfg.freq_hz = newval; |
| 83 | + if (ledc_timer_config(&timer_cfg) != ESP_OK) { |
| 84 | + timer_cfg.freq_hz = oval; |
| 85 | + return 0; |
| 86 | + } |
| 87 | + return 1; |
| 88 | +} |
| 89 | + |
| 90 | +/******************************************************************************/ |
| 91 | + |
| 92 | +// MicroPython bindings for PWM |
| 93 | + |
| 94 | +STATIC void esp32_pwm_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) { |
| 95 | + esp32_pwm_obj_t *self = MP_OBJ_TO_PTR(self_in); |
| 96 | + mp_printf(print, "PWM(%u", self->pin); |
| 97 | + if (self->active) { |
| 98 | + mp_printf(print, ", freq=%u, duty=%u", timer_cfg.freq_hz, |
| 99 | + ledc_get_duty(PWMODE, self->channel)); |
| 100 | + } |
| 101 | + mp_printf(print, ")"); |
| 102 | +} |
| 103 | + |
| 104 | +STATIC void esp32_pwm_init_helper(esp32_pwm_obj_t *self, |
| 105 | + size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { |
| 106 | + enum { ARG_freq, ARG_duty }; |
| 107 | + static const mp_arg_t allowed_args[] = { |
| 108 | + { MP_QSTR_freq, MP_ARG_INT, {.u_int = -1} }, |
| 109 | + { MP_QSTR_duty, MP_ARG_INT, {.u_int = -1} }, |
| 110 | + }; |
| 111 | + mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)]; |
| 112 | + mp_arg_parse_all(n_args, pos_args, kw_args, |
| 113 | + MP_ARRAY_SIZE(allowed_args), allowed_args, args); |
| 114 | + |
| 115 | + int channel; |
| 116 | + int avail = -1; |
| 117 | + |
| 118 | + // Find a free PWM channel, also spot if our pin is |
| 119 | + // already mentioned. |
| 120 | + for (channel = 0; channel < LEDC_CHANNEL_MAX; ++channel) { |
| 121 | + if (chan_gpio[channel] == self->pin) { |
| 122 | + break; |
| 123 | + } |
| 124 | + if ((avail == -1) && (chan_gpio[channel] == -1)) { |
| 125 | + avail = channel; |
| 126 | + } |
| 127 | + } |
| 128 | + if (channel >= LEDC_CHANNEL_MAX) { |
| 129 | + if (avail == -1) { |
| 130 | + mp_raise_ValueError("out of PWM channels"); |
| 131 | + } |
| 132 | + channel = avail; |
| 133 | + } |
| 134 | + |
| 135 | + // New PWM assignment |
| 136 | + self->active = 1; |
| 137 | + if (chan_gpio[channel] == -1) { |
| 138 | + ledc_channel_config_t cfg = { |
| 139 | + .channel = channel, |
| 140 | + .duty = (1 << PWRES) / 2, |
| 141 | + .gpio_num = self->pin, |
| 142 | + .intr_type = LEDC_INTR_DISABLE, |
| 143 | + .speed_mode = PWMODE, |
| 144 | + .timer_sel = PWTIMER, |
| 145 | + }; |
| 146 | + if (ledc_channel_config(&cfg) != ESP_OK) { |
| 147 | + nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, |
| 148 | + "PWM not supported on pin %d", self->pin)); |
| 149 | + } |
| 150 | + chan_gpio[channel] = self->pin; |
| 151 | + self->channel = channel; |
| 152 | + } |
| 153 | + |
| 154 | + // Maybe change PWM timer |
| 155 | + int tval = args[ARG_freq].u_int; |
| 156 | + if (tval != -1) { |
| 157 | + if (tval != timer_cfg.freq_hz) { |
| 158 | + if (!set_freq(tval)) { |
| 159 | + nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, |
| 160 | + "Bad frequency %d", tval)); |
| 161 | + } |
| 162 | + } |
| 163 | + } |
| 164 | + |
| 165 | + // Set duty cycle? |
| 166 | + int dval = args[ARG_duty].u_int; |
| 167 | + if (dval != -1) { |
| 168 | + dval &= ((1 << PWRES)-1); |
| 169 | + ledc_set_duty(PWMODE, channel, dval); |
| 170 | + ledc_update_duty(PWMODE, channel); |
| 171 | + } |
| 172 | +} |
| 173 | + |
| 174 | +STATIC mp_obj_t esp32_pwm_make_new(const mp_obj_type_t *type, |
| 175 | + size_t n_args, size_t n_kw, const mp_obj_t *args) { |
| 176 | + mp_arg_check_num(n_args, n_kw, 1, MP_OBJ_FUN_ARGS_MAX, true); |
| 177 | + gpio_num_t pin_id = machine_pin_get_id(args[0]); |
| 178 | + |
| 179 | + // create PWM object from the given pin |
| 180 | + esp32_pwm_obj_t *self = m_new_obj(esp32_pwm_obj_t); |
| 181 | + self->base.type = &machine_pwm_type; |
| 182 | + self->pin = pin_id; |
| 183 | + self->active = 0; |
| 184 | + self->channel = -1; |
| 185 | + |
| 186 | + // start the PWM subsystem if it's not already running |
| 187 | + if (!pwm_inited) { |
| 188 | + pwm_init(); |
| 189 | + pwm_inited = true; |
| 190 | + } |
| 191 | + |
| 192 | + // start the PWM running for this channel |
| 193 | + mp_map_t kw_args; |
| 194 | + mp_map_init_fixed_table(&kw_args, n_kw, args + n_args); |
| 195 | + esp32_pwm_init_helper(self, n_args - 1, args + 1, &kw_args); |
| 196 | + |
| 197 | + return MP_OBJ_FROM_PTR(self); |
| 198 | +} |
| 199 | + |
| 200 | +STATIC mp_obj_t esp32_pwm_init(size_t n_args, |
| 201 | + const mp_obj_t *args, mp_map_t *kw_args) { |
| 202 | + esp32_pwm_init_helper(args[0], n_args - 1, args + 1, kw_args); |
| 203 | + return mp_const_none; |
| 204 | +} |
| 205 | +MP_DEFINE_CONST_FUN_OBJ_KW(esp32_pwm_init_obj, 1, esp32_pwm_init); |
| 206 | + |
| 207 | +STATIC mp_obj_t esp32_pwm_deinit(mp_obj_t self_in) { |
| 208 | + esp32_pwm_obj_t *self = MP_OBJ_TO_PTR(self_in); |
| 209 | + int chan = self->channel; |
| 210 | + |
| 211 | + // Valid channel? |
| 212 | + if ((chan >= 0) && (chan < LEDC_CHANNEL_MAX)) { |
| 213 | + // Mark it unused, and tell the hardware to stop routing |
| 214 | + chan_gpio[chan] = -1; |
| 215 | + ledc_stop(PWMODE, chan, 0); |
| 216 | + self->active = 0; |
| 217 | + self->channel = -1; |
| 218 | + } |
| 219 | + return mp_const_none; |
| 220 | +} |
| 221 | +STATIC MP_DEFINE_CONST_FUN_OBJ_1(esp32_pwm_deinit_obj, esp32_pwm_deinit); |
| 222 | + |
| 223 | +STATIC mp_obj_t esp32_pwm_freq(size_t n_args, const mp_obj_t *args) { |
| 224 | + if (n_args == 1) { |
| 225 | + // get |
| 226 | + return MP_OBJ_NEW_SMALL_INT(timer_cfg.freq_hz); |
| 227 | + } |
| 228 | + |
| 229 | + // set |
| 230 | + int tval = mp_obj_get_int(args[1]); |
| 231 | + if (!set_freq(tval)) { |
| 232 | + nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, |
| 233 | + "Bad frequency %d", tval)); |
| 234 | + } |
| 235 | + return mp_const_none; |
| 236 | +} |
| 237 | + |
| 238 | +STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(esp32_pwm_freq_obj, 1, 2, esp32_pwm_freq); |
| 239 | + |
| 240 | +STATIC mp_obj_t esp32_pwm_duty(size_t n_args, const mp_obj_t *args) { |
| 241 | + esp32_pwm_obj_t *self = MP_OBJ_TO_PTR(args[0]); |
| 242 | + int duty; |
| 243 | + |
| 244 | + if (n_args == 1) { |
| 245 | + // get |
| 246 | + duty = ledc_get_duty(PWMODE, self->channel); |
| 247 | + return MP_OBJ_NEW_SMALL_INT(duty); |
| 248 | + } |
| 249 | + |
| 250 | + // set |
| 251 | + duty = mp_obj_get_int(args[1]); |
| 252 | + duty &= ((1 << PWRES)-1); |
| 253 | + ledc_set_duty(PWMODE, self->channel, duty); |
| 254 | + ledc_update_duty(PWMODE, self->channel); |
| 255 | + |
| 256 | + return mp_const_none; |
| 257 | +} |
| 258 | +STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(esp32_pwm_duty_obj, |
| 259 | + 1, 2, esp32_pwm_duty); |
| 260 | + |
| 261 | +STATIC const mp_rom_map_elem_t esp32_pwm_locals_dict_table[] = { |
| 262 | + { MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&esp32_pwm_init_obj) }, |
| 263 | + { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&esp32_pwm_deinit_obj) }, |
| 264 | + { MP_ROM_QSTR(MP_QSTR_freq), MP_ROM_PTR(&esp32_pwm_freq_obj) }, |
| 265 | + { MP_ROM_QSTR(MP_QSTR_duty), MP_ROM_PTR(&esp32_pwm_duty_obj) }, |
| 266 | +}; |
| 267 | + |
| 268 | +STATIC MP_DEFINE_CONST_DICT(esp32_pwm_locals_dict, |
| 269 | + esp32_pwm_locals_dict_table); |
| 270 | + |
| 271 | +const mp_obj_type_t machine_pwm_type = { |
| 272 | + { &mp_type_type }, |
| 273 | + .name = MP_QSTR_PWM, |
| 274 | + .print = esp32_pwm_print, |
| 275 | + .make_new = esp32_pwm_make_new, |
| 276 | + .locals_dict = (mp_obj_dict_t*)&esp32_pwm_locals_dict, |
| 277 | +}; |
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