esp32-hal-ledc.c

// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at

// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include"esp32-hal.h"
#include"freertos/FreeRTOS.h"
#include"freertos/task.h"
#include"freertos/semphr.h"
#include"rom/ets_sys.h"
#include"esp32-hal-matrix.h"
#include"soc/dport_reg.h"
#include"soc/ledc_reg.h"
#include"soc/ledc_struct.h"

#ifCONFIG_DISABLE_HAL_LOCKS
#defineLEDC_MUTEX_LOCK()
#defineLEDC_MUTEX_UNLOCK()
#else
#defineLEDC_MUTEX_LOCK() do {} while (xSemaphoreTake(_ledc_sys_lock, portMAX_DELAY) != pdPASS)
#defineLEDC_MUTEX_UNLOCK() xSemaphoreGive(_ledc_sys_lock)
xSemaphoreHandle_ledc_sys_lock;
#endif

/*
 * LEDC Chan to Group/Channel/Timer Mapping
** ledc: 0 => Group: 0, Channel: 0, Timer: 0
** ledc: 1 => Group: 0, Channel: 1, Timer: 0
** ledc: 2 => Group: 0, Channel: 2, Timer: 1
** ledc: 3 => Group: 0, Channel: 3, Timer: 1
** ledc: 4 => Group: 0, Channel: 4, Timer: 2
** ledc: 5 => Group: 0, Channel: 5, Timer: 2
** ledc: 6 => Group: 0, Channel: 6, Timer: 3
** ledc: 7 => Group: 0, Channel: 7, Timer: 3
** ledc: 8 => Group: 1, Channel: 0, Timer: 0
** ledc: 9 => Group: 1, Channel: 1, Timer: 0
** ledc: 10 => Group: 1, Channel: 2, Timer: 1
** ledc: 11 => Group: 1, Channel: 3, Timer: 1
** ledc: 12 => Group: 1, Channel: 4, Timer: 2
** ledc: 13 => Group: 1, Channel: 5, Timer: 2
** ledc: 14 => Group: 1, Channel: 6, Timer: 3
** ledc: 15 => Group: 1, Channel: 7, Timer: 3
*/
#defineLEDC_CHAN(g,c) LEDC.channel_group[(g)].channel[(c)]
#defineLEDC_TIMER(g,t) LEDC.timer_group[(g)].timer[(t)]

staticvoid_on_apb_change(void*arg, apb_change_ev_tev_type, uint32_told_apb, uint32_tnew_apb){
if(ev_type==APB_AFTER_CHANGE&&old_apb!=new_apb){
uint32_tiarg= (uint32_t)arg;
uint8_tchan=iarg;
uint8_tgroup=(chan/8), timer=((chan/2)%4);
old_apb /= 1000000;
new_apb /= 1000000;
if(LEDC_TIMER(group, timer).conf.tick_sel){
LEDC_MUTEX_LOCK();
uint32_told_div=LEDC_TIMER(group, timer).conf.clock_divider;
uint32_tdiv_num= (new_apb*old_div) / old_apb;
if(div_num>LEDC_DIV_NUM_HSTIMER0_V){
new_apb=REF_CLK_FREQ / 1000000;
div_num= (new_apb*old_div) / old_apb;
if(div_num>LEDC_DIV_NUM_HSTIMER0_V) {
div_num=LEDC_DIV_NUM_HSTIMER0_V;//lowest clock possible
 }
LEDC_TIMER(group, timer).conf.tick_sel=0;
 } elseif(div_num<256) {
div_num=256;//highest clock possible
 }
LEDC_TIMER(group, timer).conf.clock_divider=div_num;
LEDC_MUTEX_UNLOCK();
 }
 }
}

//uint32_t frequency = (80MHz or 1MHz)/((div_num / 256.0)*(1 << bit_num));
staticvoid_ledcSetupTimer(uint8_tchan, uint32_tdiv_num, uint8_tbit_num, boolapb_clk)
{
uint8_tgroup=(chan/8), timer=((chan/2)%4);
staticbooltHasStarted= false;
if(!tHasStarted) {
tHasStarted= true;
DPORT_SET_PERI_REG_MASK(DPORT_PERIP_CLK_EN_REG, DPORT_LEDC_CLK_EN);
DPORT_CLEAR_PERI_REG_MASK(DPORT_PERIP_RST_EN_REG, DPORT_LEDC_RST);
LEDC.conf.apb_clk_sel=1;//LS use apb clock
#if !CONFIG_DISABLE_HAL_LOCKS
_ledc_sys_lock=xSemaphoreCreateMutex();
#endif
 }
LEDC_MUTEX_LOCK();
LEDC_TIMER(group, timer).conf.clock_divider=div_num;//18 bit (10.8) This register is used to configure parameter for divider in timer the least significant eight bits represent the decimal part.
LEDC_TIMER(group, timer).conf.duty_resolution=bit_num;//5 bit This register controls the range of the counter in timer. the counter range is [0 2**bit_num] the max bit width for counter is 20.
LEDC_TIMER(group, timer).conf.tick_sel=apb_clk;//apb clock
if(group) {
LEDC_TIMER(group, timer).conf.low_speed_update=1;//This bit is only useful for low speed timer channels, reserved for high speed timers
 }
LEDC_TIMER(group, timer).conf.pause=0;
LEDC_TIMER(group, timer).conf.rst=1;//This bit is used to reset timer the counter will be 0 after reset.
LEDC_TIMER(group, timer).conf.rst=0;
LEDC_MUTEX_UNLOCK();
uint32_tiarg=chan;
addApbChangeCallback((void*)iarg, _on_apb_change);
}

//max div_num 0x3FFFF (262143)
//max bit_num 0x1F (31)
staticdouble_ledcSetupTimerFreq(uint8_tchan, doublefreq, uint8_tbit_num)
{
uint64_tclk_freq=getApbFrequency();
clk_freq <<= 8;//div_num is 8 bit decimal
uint32_tdiv_num= (clk_freq >> bit_num) / freq;
boolapb_clk= true;
if(div_num>LEDC_DIV_NUM_HSTIMER0_V) {
clk_freq /= 80;
div_num= (clk_freq >> bit_num) / freq;
if(div_num>LEDC_DIV_NUM_HSTIMER0_V) {
div_num=LEDC_DIV_NUM_HSTIMER0_V;//lowest clock possible
 }
apb_clk= false;
 } elseif(div_num<256) {
div_num=256;//highest clock possible
 }
_ledcSetupTimer(chan, div_num, bit_num, apb_clk);
//log_i("Fin: %f, Fclk: %uMhz, bits: %u, DIV: %u, Fout: %f",
// freq, apb_clk?80:1, bit_num, div_num, (clk_freq >> bit_num) / (double)div_num);
return (clk_freq >> bit_num) / (double)div_num;
}

staticdouble_ledcTimerRead(uint8_tchan)
{
uint32_tdiv_num;
uint8_tbit_num;
boolapb_clk;
uint8_tgroup=(chan/8), timer=((chan/2)%4);
LEDC_MUTEX_LOCK();
div_num=LEDC_TIMER(group, timer).conf.clock_divider;//18 bit (10.8) This register is used to configure parameter for divider in timer the least significant eight bits represent the decimal part.
bit_num=LEDC_TIMER(group, timer).conf.duty_resolution;//5 bit This register controls the range of the counter in timer. the counter range is [0 2**bit_num] the max bit width for counter is 20.
apb_clk=LEDC_TIMER(group, timer).conf.tick_sel;//apb clock
LEDC_MUTEX_UNLOCK();
uint64_tclk_freq=1000000;
if(apb_clk) {
clk_freq=getApbFrequency();
 }
clk_freq <<= 8;//div_num is 8 bit decimal
return (clk_freq >> bit_num) / (double)div_num;
}

staticvoid_ledcSetupChannel(uint8_tchan, uint8_tidle_level)
{
uint8_tgroup=(chan/8), channel=(chan%8), timer=((chan/2)%4);
LEDC_MUTEX_LOCK();
LEDC_CHAN(group, channel).conf0.timer_sel=timer;//2 bit Selects the timer to attach 0-3
LEDC_CHAN(group, channel).conf0.idle_lv=idle_level;//1 bit This bit is used to control the output value when channel is off.
LEDC_CHAN(group, channel).hpoint.hpoint=0;//20 bit The output value changes to high when timer selected by channel has reached hpoint
LEDC_CHAN(group, channel).conf1.duty_inc=1;//1 bit This register is used to increase the duty of output signal or decrease the duty of output signal for high speed channel
LEDC_CHAN(group, channel).conf1.duty_num=1;//10 bit This register is used to control the number of increased or decreased times for channel
LEDC_CHAN(group, channel).conf1.duty_cycle=1;//10 bit This register is used to increase or decrease the duty every duty_cycle cycles for channel
LEDC_CHAN(group, channel).conf1.duty_scale=0;//10 bit This register controls the increase or decrease step scale for channel.
LEDC_CHAN(group, channel).duty.duty=0;
LEDC_CHAN(group, channel).conf0.sig_out_en=0;//This is the output enable control bit for channel
LEDC_CHAN(group, channel).conf1.duty_start=0;//When duty_num duty_cycle and duty_scale has been configured. these register won't take effect until set duty_start. this bit is automatically cleared by hardware.
if(group) {
LEDC_CHAN(group, channel).conf0.val &= ~BIT(4);
 } else {
LEDC_CHAN(group, channel).conf0.clk_en=0;
 }
LEDC_MUTEX_UNLOCK();
}

doubleledcSetup(uint8_tchan, doublefreq, uint8_tbit_num)
{
if(chan>15) {
return0;
 }
doubleres_freq=_ledcSetupTimerFreq(chan, freq, bit_num);
_ledcSetupChannel(chan, LOW);
returnres_freq;
}

voidledcWrite(uint8_tchan, uint32_tduty)
{
if(chan>15) {
return;
 }
uint8_tgroup=(chan/8), channel=(chan%8);
LEDC_MUTEX_LOCK();
LEDC_CHAN(group, channel).duty.duty=duty << 4;//25 bit (21.4)
if(duty) {
LEDC_CHAN(group, channel).conf0.sig_out_en=1;//This is the output enable control bit for channel
LEDC_CHAN(group, channel).conf1.duty_start=1;//When duty_num duty_cycle and duty_scale has been configured. these register won't take effect until set duty_start. this bit is automatically cleared by hardware.
if(group) {
LEDC_CHAN(group, channel).conf0.val |= BIT(4);
 } else {
LEDC_CHAN(group, channel).conf0.clk_en=1;
 }
 } else {
LEDC_CHAN(group, channel).conf0.sig_out_en=0;//This is the output enable control bit for channel
LEDC_CHAN(group, channel).conf1.duty_start=0;//When duty_num duty_cycle and duty_scale has been configured. these register won't take effect until set duty_start. this bit is automatically cleared by hardware.
if(group) {
LEDC_CHAN(group, channel).conf0.val &= ~BIT(4);
 } else {
LEDC_CHAN(group, channel).conf0.clk_en=0;
 }
 }
LEDC_MUTEX_UNLOCK();
}

uint32_tledcRead(uint8_tchan)
{
if(chan>15) {
return0;
 }
returnLEDC.channel_group[chan/8].channel[chan%8].duty.duty >> 4;
}

doubleledcReadFreq(uint8_tchan)
{
if(!ledcRead(chan)){
return0;
 }
return_ledcTimerRead(chan);
}

doubleledcWriteTone(uint8_tchan, doublefreq)
{
if(chan>15) {
return0;
 }
if(!freq) {
ledcWrite(chan, 0);
return0;
 }
doubleres_freq=_ledcSetupTimerFreq(chan, freq, 10);
ledcWrite(chan, 0x1FF);
returnres_freq;
}

doubleledcWriteNote(uint8_tchan, note_tnote, uint8_toctave){
constuint16_tnoteFrequencyBase[12] = {
// C C# D Eb E F F# G G# A Bb B
4186, 4435, 4699, 4978, 5274, 5588, 5920, 6272, 6645, 7040, 7459, 7902
 };

if(octave>8||note >= NOTE_MAX){
return0;
 }
doublenoteFreq= (double)noteFrequencyBase[note] / (double)(1 << (8-octave));
returnledcWriteTone(chan, noteFreq);
}

voidledcAttachPin(uint8_tpin, uint8_tchan)
{
if(chan>15) {
return;
 }
pinMode(pin, OUTPUT);
pinMatrixOutAttach(pin, ((chan/8)?LEDC_LS_SIG_OUT0_IDX:LEDC_HS_SIG_OUT0_IDX) + (chan%8), false, false);
}

voidledcDetachPin(uint8_tpin)
{
pinMatrixOutDetach(pin, false, false);
}