161 lines
6.1 KiB
C
161 lines
6.1 KiB
C
/*
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* This file is part of the MicroPython 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) 2020-2021 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 "py/runtime.h"
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#include "py/mphal.h"
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#include "modmachine.h"
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#include "hardware/clocks.h"
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#include "hardware/pwm.h"
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/******************************************************************************/
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// MicroPython bindings for machine.PWM
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typedef struct _machine_pwm_obj_t {
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mp_obj_base_t base;
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uint8_t slice;
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uint8_t channel;
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} machine_pwm_obj_t;
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STATIC machine_pwm_obj_t machine_pwm_obj[] = {
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{{&machine_pwm_type}, 0, PWM_CHAN_A},
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{{&machine_pwm_type}, 0, PWM_CHAN_B},
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{{&machine_pwm_type}, 1, PWM_CHAN_A},
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{{&machine_pwm_type}, 1, PWM_CHAN_B},
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{{&machine_pwm_type}, 2, PWM_CHAN_A},
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{{&machine_pwm_type}, 2, PWM_CHAN_B},
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{{&machine_pwm_type}, 3, PWM_CHAN_A},
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{{&machine_pwm_type}, 3, PWM_CHAN_B},
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{{&machine_pwm_type}, 4, PWM_CHAN_A},
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{{&machine_pwm_type}, 4, PWM_CHAN_B},
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{{&machine_pwm_type}, 5, PWM_CHAN_A},
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{{&machine_pwm_type}, 5, PWM_CHAN_B},
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{{&machine_pwm_type}, 6, PWM_CHAN_A},
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{{&machine_pwm_type}, 6, PWM_CHAN_B},
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{{&machine_pwm_type}, 7, PWM_CHAN_A},
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{{&machine_pwm_type}, 7, PWM_CHAN_B},
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};
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STATIC void mp_machine_pwm_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
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machine_pwm_obj_t *self = MP_OBJ_TO_PTR(self_in);
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mp_printf(print, "<PWM slice=%u channel=%u>", self->slice, self->channel);
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}
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// PWM(pin)
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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) {
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// Check number of arguments
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mp_arg_check_num(n_args, n_kw, 1, 1, false);
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// Get GPIO to connect to PWM.
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uint32_t gpio = mp_hal_get_pin_obj(all_args[0]);
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// Get static peripheral object.
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uint slice = pwm_gpio_to_slice_num(gpio);
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uint8_t channel = pwm_gpio_to_channel(gpio);
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const machine_pwm_obj_t *self = &machine_pwm_obj[slice * 2 + channel];
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// Select PWM function for given GPIO.
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gpio_set_function(gpio, GPIO_FUNC_PWM);
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return MP_OBJ_FROM_PTR(self);
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}
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STATIC void mp_machine_pwm_deinit(machine_pwm_obj_t *self) {
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pwm_set_enabled(self->slice, false);
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}
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STATIC mp_obj_t mp_machine_pwm_freq_get(machine_pwm_obj_t *self) {
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uint32_t source_hz = clock_get_hz(clk_sys);
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uint32_t div16 = pwm_hw->slice[self->slice].div;
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uint32_t top = pwm_hw->slice[self->slice].top;
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uint32_t pwm_freq = 16 * source_hz / div16 / top;
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return MP_OBJ_NEW_SMALL_INT(pwm_freq);
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}
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STATIC void mp_machine_pwm_freq_set(machine_pwm_obj_t *self, mp_int_t freq) {
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// Set the frequency, making "top" as large as possible for maximum resolution.
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// Maximum "top" is set at 65534 to be able to achieve 100% duty with 65535.
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#define TOP_MAX 65534
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uint32_t source_hz = clock_get_hz(clk_sys);
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uint32_t div16_top = 16 * source_hz / freq;
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uint32_t top = 1;
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for (;;) {
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// Try a few small prime factors to get close to the desired frequency.
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if (div16_top >= 16 * 5 && div16_top % 5 == 0 && top * 5 <= TOP_MAX) {
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div16_top /= 5;
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top *= 5;
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} else if (div16_top >= 16 * 3 && div16_top % 3 == 0 && top * 3 <= TOP_MAX) {
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div16_top /= 3;
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top *= 3;
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} else if (div16_top >= 16 * 2 && top * 2 <= TOP_MAX) {
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div16_top /= 2;
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top *= 2;
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} else {
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break;
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}
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}
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if (div16_top < 16) {
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mp_raise_ValueError(MP_ERROR_TEXT("freq too large"));
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} else if (div16_top >= 256 * 16) {
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mp_raise_ValueError(MP_ERROR_TEXT("freq too small"));
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}
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pwm_hw->slice[self->slice].div = div16_top;
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pwm_hw->slice[self->slice].top = top;
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}
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STATIC mp_obj_t mp_machine_pwm_duty_get_u16(machine_pwm_obj_t *self) {
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uint32_t top = pwm_hw->slice[self->slice].top;
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uint32_t cc = pwm_hw->slice[self->slice].cc;
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cc = (cc >> (self->channel ? PWM_CH0_CC_B_LSB : PWM_CH0_CC_A_LSB)) & 0xffff;
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return MP_OBJ_NEW_SMALL_INT(cc * 65535 / (top + 1));
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}
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STATIC void mp_machine_pwm_duty_set_u16(machine_pwm_obj_t *self, mp_int_t duty_u16) {
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uint32_t top = pwm_hw->slice[self->slice].top;
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uint32_t cc = duty_u16 * (top + 1) / 65535;
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pwm_set_chan_level(self->slice, self->channel, cc);
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pwm_set_enabled(self->slice, true);
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}
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STATIC mp_obj_t mp_machine_pwm_duty_get_ns(machine_pwm_obj_t *self) {
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uint32_t source_hz = clock_get_hz(clk_sys);
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uint32_t slice_hz = 16 * source_hz / pwm_hw->slice[self->slice].div;
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uint32_t cc = pwm_hw->slice[self->slice].cc;
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cc = (cc >> (self->channel ? PWM_CH0_CC_B_LSB : PWM_CH0_CC_A_LSB)) & 0xffff;
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return MP_OBJ_NEW_SMALL_INT((uint64_t)cc * 1000000000ULL / slice_hz);
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}
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STATIC void mp_machine_pwm_duty_set_ns(machine_pwm_obj_t *self, mp_int_t duty_ns) {
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uint32_t source_hz = clock_get_hz(clk_sys);
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uint32_t slice_hz = 16 * source_hz / pwm_hw->slice[self->slice].div;
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uint32_t cc = (uint64_t)duty_ns * slice_hz / 1000000000ULL;
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if (cc > 65535) {
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mp_raise_ValueError(MP_ERROR_TEXT("duty larger than period"));
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}
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pwm_set_chan_level(self->slice, self->channel, cc);
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pwm_set_enabled(self->slice, true);
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}
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