Tasmota/sonoff/core_esp8266_wiring_pwm.c

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/*
pwm.c - analogWrite implementation for esp8266
Copyright (c) 2015 Hristo Gochkov. All rights reserved.
This file is part of the esp8266 core for Arduino environment.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "wiring_private.h"
#include "pins_arduino.h"
#include "c_types.h"
#include "eagle_soc.h"
#include "ets_sys.h"
#ifndef F_CPU
#define F_CPU 800000000L
#endif
struct pwm_isr_table {
uint8_t len;
uint16_t steps[17];
uint32_t masks[17];
};
struct pwm_isr_data {
struct pwm_isr_table tables[2];
uint8_t active;//0 or 1, which table is active in ISR
};
static struct pwm_isr_data _pwm_isr_data;
uint32_t pwm_mask = 0;
uint16_t pwm_values[17] = {0,};
uint32_t pwm_freq = 1000;
uint32_t pwm_range = PWMRANGE;
uint8_t pwm_steps_changed = 0;
uint32_t pwm_multiplier = 0;
int pwm_sort_array(uint16_t a[], uint16_t al)
{
uint16_t i, j;
for (i = 1; i < al; i++) {
uint16_t tmp = a[i];
for (j = i; j >= 1 && tmp < a[j-1]; j--) {
a[j] = a[j-1];
}
a[j] = tmp;
}
int bl = 1;
for(i = 1; i < al; i++) {
if(a[i] != a[i-1]) {
a[bl++] = a[i];
}
}
return bl;
}
uint32_t pwm_get_mask(uint16_t value)
{
uint32_t mask = 0;
int i;
for(i=0; i<17; i++) {
if((pwm_mask & (1 << i)) != 0 && pwm_values[i] == value) {
mask |= (1 << i);
}
}
return mask;
}
void prep_pwm_steps()
{
if(pwm_mask == 0) {
return;
}
int pwm_temp_steps_len = 0;
uint16_t pwm_temp_steps[17];
uint32_t pwm_temp_masks[17];
uint32_t range = pwm_range;
if((F_CPU / ESP8266_CLOCK) == 1) {
range /= 2;
}
int i;
for(i=0; i<17; i++) {
if((pwm_mask & (1 << i)) != 0 && pwm_values[i] != 0) {
pwm_temp_steps[pwm_temp_steps_len++] = pwm_values[i];
}
}
pwm_temp_steps[pwm_temp_steps_len++] = range;
pwm_temp_steps_len = pwm_sort_array(pwm_temp_steps, pwm_temp_steps_len) - 1;
for(i=0; i<pwm_temp_steps_len; i++) {
pwm_temp_masks[i] = pwm_get_mask(pwm_temp_steps[i]);
}
for(i=pwm_temp_steps_len; i>0; i--) {
pwm_temp_steps[i] = pwm_temp_steps[i] - pwm_temp_steps[i-1];
}
pwm_steps_changed = 0;
struct pwm_isr_table *table = &(_pwm_isr_data.tables[!_pwm_isr_data.active]);
table->len = pwm_temp_steps_len;
ets_memcpy(table->steps, pwm_temp_steps, (pwm_temp_steps_len + 1) * 2);
ets_memcpy(table->masks, pwm_temp_masks, pwm_temp_steps_len * 4);
pwm_multiplier = ESP8266_CLOCK/(range * pwm_freq);
pwm_steps_changed = 1;
}
void ICACHE_RAM_ATTR pwm_timer_isr() //103-138
{
struct pwm_isr_table *table = &(_pwm_isr_data.tables[_pwm_isr_data.active]);
static uint8_t current_step = 0;
TEIE &= ~TEIE1;//14
T1I = 0;//9
if(current_step < table->len) { //20/21
uint32_t mask = table->masks[current_step] & pwm_mask;
if(mask & 0xFFFF) {
GPOC = mask & 0xFFFF; //15/21
}
if(mask & 0x10000) {
GP16O = 0; //6/13
}
current_step++;//1
} else {
current_step = 0;//1
if(pwm_mask == 0) { //12
table->len = 0;
return;
}
if(pwm_mask & 0xFFFF) {
GPOS = pwm_mask & 0xFFFF; //11
}
if(pwm_mask & 0x10000) {
GP16O = 1; //5/13
}
if(pwm_steps_changed) { //12/21
_pwm_isr_data.active = !_pwm_isr_data.active;
table = &(_pwm_isr_data.tables[_pwm_isr_data.active]);
pwm_steps_changed = 0;
}
}
T1L = (table->steps[current_step] * pwm_multiplier);//23
TEIE |= TEIE1;//13
}
void pwm_start_timer()
{
timer1_disable();
ETS_FRC_TIMER1_INTR_ATTACH(NULL, NULL);
ETS_FRC_TIMER1_NMI_INTR_ATTACH(pwm_timer_isr);
timer1_enable(TIM_DIV1, TIM_EDGE, TIM_SINGLE);
timer1_write(1);
}
void ICACHE_RAM_ATTR pwm_stop_pin(uint8_t pin)
{
if(pwm_mask){
pwm_mask &= ~(1 << pin);
if(pwm_mask == 0) {
ETS_FRC_TIMER1_NMI_INTR_ATTACH(NULL);
timer1_disable();
timer1_isr_init();
}
}
}
extern void __analogWrite(uint8_t pin, int value)
{
bool start_timer = false;
if(value == 0) {
digitalWrite(pin, LOW);
prep_pwm_steps();
return;
}
if((pwm_mask & (1 << pin)) == 0) {
if(pwm_mask == 0) {
memset(&_pwm_isr_data, 0, sizeof(_pwm_isr_data));
start_timer = true;
}
pinMode(pin, OUTPUT);
digitalWrite(pin, LOW);
pwm_mask |= (1 << pin);
}
if((F_CPU / ESP8266_CLOCK) == 1) {
value = (value+1) / 2;
}
pwm_values[pin] = value % (pwm_range + 1);
prep_pwm_steps();
if(start_timer) {
pwm_start_timer();
}
}
extern void __analogWriteFreq(uint32_t freq)
{
pwm_freq = freq;
prep_pwm_steps();
}
extern void __analogWriteRange(uint32_t range)
{
pwm_range = range;
prep_pwm_steps();
}
extern void analogWrite(uint8_t pin, int val) __attribute__ ((weak, alias("__analogWrite")));
extern void analogWriteFreq(uint32_t freq) __attribute__ ((weak, alias("__analogWriteFreq")));
extern void analogWriteRange(uint32_t range) __attribute__ ((weak, alias("__analogWriteRange")));