circuitpython/esp8266/common-hal/nativeio/PWMOut.c
Scott Shawcroft e3f9ee839a Add frequency changing support to PWMOut.
You can either set it once up front, or set variable_frequency on custruction to
indicate that the frequency must be able to change. This informs whether a timer
can be shared amongst pins.

This also adds persistent clock calibration on atmel-samd. Once the device has
synced its clock frequency over USB it will remember that config value until USB
is used again. This helps ensure the clock frequency is similar on and off USB.

Lastly, this also corrects time.sleep() when on USB by correcting the tick counter.
2017-01-30 15:02:01 -08:00

119 lines
4.2 KiB
C

/*
* 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 <stdint.h>
#include "esppwm.h"
#include "py/runtime.h"
#include "shared-bindings/nativeio/PWMOut.h"
#include "eagle_soc.h"
#include "c_types.h"
#include "gpio.h"
#define PWM_FREQ_MAX 1000
// Shared with pybpwm
extern bool pwm_inited;
bool first_channel_variable;
void pwmout_reset(void) {
first_channel_variable = false;
}
void common_hal_nativeio_pwmout_construct(nativeio_pwmout_obj_t* self, const mcu_pin_obj_t* pin, uint16_t duty, uint32_t frequency,
bool variable_frequency) {
if (frequency > PWM_FREQ_MAX) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_OSError,
"Maximum PWM frequency is %dhz.", PWM_FREQ_MAX));
} else if (frequency < 1) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError,
"Minimum PWM frequency is 1hz."));
}
// start the PWM subsystem if it's not already running
if (!pwm_inited) {
pwm_init();
pwm_inited = true;
pwm_set_freq(frequency, 0);
first_channel_variable = variable_frequency;
} else if (first_channel_variable || pwm_get_freq(0) != frequency) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_OSError,
"Multiple PWM frequencies not supported. PWM already set to %dhz.", pwm_get_freq(0)));
}
self->channel = pwm_add(pin->gpio_number,
pin->peripheral,
pin->gpio_function);
self->pin = pin;
if (self->channel == -1) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_OSError,
"PWM not supported on pin %d", pin->gpio_number));
}
}
extern void common_hal_nativeio_pwmout_deinit(nativeio_pwmout_obj_t* self) {
pwm_delete(self->channel);
pwm_start();
if (self->pin->gpio_number < 16) {
uint32_t pin_mask = 1 << self->pin->gpio_number;
gpio_output_set(0x0, 0x0, 0x0, pin_mask);
PIN_FUNC_SELECT(self->pin->peripheral, 0);
PIN_PULLUP_DIS(self->pin->peripheral);
}
}
extern void common_hal_nativeio_pwmout_set_duty_cycle(nativeio_pwmout_obj_t* self, uint16_t duty) {
// We get 16 bits of duty in but the underlying code is only ten bit.
pwm_set_duty(duty >> 6, self->channel);
pwm_start();
}
uint16_t common_hal_nativeio_pwmout_get_duty_cycle(nativeio_pwmout_obj_t* self) {
return pwm_get_duty(self->channel) << 6;
}
void common_hal_nativeio_pwmout_set_frequency(nativeio_pwmout_obj_t* self, uint32_t frequency) {
if (frequency > PWM_FREQ_MAX) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_OSError,
"Maximum PWM frequency is %dhz.", PWM_FREQ_MAX));
} else if (frequency < 1) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError,
"Minimum PWM frequency is 1hz."));
}
pwm_set_freq(frequency, 0);
}
uint32_t common_hal_nativeio_pwmout_get_frequency(nativeio_pwmout_obj_t* self) {
return pwm_get_freq(0);
}
bool common_hal_nativeio_pwmout_get_variable_frequency(nativeio_pwmout_obj_t* self) {
return first_channel_variable;
}