circuitpython/ports/esp8266/esppwm.c

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/******************************************************************************
* Copyright 2013-2014 Espressif Systems (Wuxi)
*
* FileName: pwm.c
*
* Description: pwm driver
*
* Modification history:
* 2014/5/1, v1.0 create this file.
* 2016/3/2: Modifications by dpgeorge to suit MicroPython
*******************************************************************************/
#include <stdio.h>
#include <string.h>
#include "etshal.h"
#include "os_type.h"
#include "gpio.h"
#include "esppwm.h"
#include "py/mpprint.h"
#define PWM_DBG(...)
// #define PWM_DBG(...) mp_printf(&mp_plat_print, __VA_ARGS__)
#define ICACHE_RAM_ATTR // __attribute__((section(".text")))
#define PWM_CHANNEL 8
#define PWM_DEPTH 1023
#define PWM_FREQ_MAX 1000
#define PWM_1S 1000000
struct pwm_single_param {
uint16_t gpio_set;
uint16_t gpio_clear;
uint32_t h_time;
};
struct pwm_param {
uint32_t period;
uint16_t freq;
uint16_t duty[PWM_CHANNEL];
};
STATIC const uint8_t pin_num[PWM_CHANNEL] = {0, 2, 4, 5, 12, 13, 14, 15};
STATIC struct pwm_single_param pwm_single_toggle[2][PWM_CHANNEL + 1];
STATIC struct pwm_single_param *pwm_single;
STATIC struct pwm_param pwm;
STATIC int8_t pwm_out_io_num[PWM_CHANNEL] = {-1, -1, -1, -1, -1, -1, -1, -1};
STATIC uint8_t pwm_channel_toggle[2];
STATIC uint8_t *pwm_channel;
STATIC uint8_t pwm_toggle = 1;
STATIC uint8_t pwm_timer_down = 1;
STATIC uint8_t pwm_current_channel = 0;
STATIC uint16_t pwm_gpio = 0;
STATIC uint8_t pwm_channel_num = 0;
STATIC volatile uint8_t pwm_toggle_request = 0;
// XXX: 0xffffffff/(80000000/16)=35A
#define US_TO_RTC_TIMER_TICKS(t) \
((t) ? \
(((t) > 0x35A) ? \
(((t) >> 2) * ((APB_CLK_FREQ >> 4) / 250000) + ((t) & 0x3) * ((APB_CLK_FREQ >> 4) / 1000000)) : \
(((t) * (APB_CLK_FREQ >> 4)) / 1000000)) : \
0)
// FRC1
#define FRC1_ENABLE_TIMER BIT7
typedef enum {
DIVDED_BY_1 = 0,
DIVDED_BY_16 = 4,
DIVDED_BY_256 = 8,
} TIMER_PREDIVED_MODE;
typedef enum {
TM_LEVEL_INT = 1,
TM_EDGE_INT = 0,
} TIMER_INT_MODE;
STATIC void ICACHE_FLASH_ATTR
pwm_insert_sort(struct pwm_single_param pwm[], uint8 n) {
uint8 i;
for (i = 1; i < n; i++) {
if (pwm[i].h_time < pwm[i - 1].h_time) {
int8 j = i - 1;
struct pwm_single_param tmp;
memcpy(&tmp, &pwm[i], sizeof(struct pwm_single_param));
memcpy(&pwm[i], &pwm[i - 1], sizeof(struct pwm_single_param));
while (tmp.h_time < pwm[j].h_time) {
memcpy(&pwm[j + 1], &pwm[j], sizeof(struct pwm_single_param));
j--;
if (j < 0) {
break;
}
}
memcpy(&pwm[j + 1], &tmp, sizeof(struct pwm_single_param));
}
}
}
STATIC volatile uint8 critical = 0;
#define LOCK_PWM(c) do { \
while ((c) == 1); \
(c) = 1; \
} while (0)
#define UNLOCK_PWM(c) do { \
(c) = 0; \
} while (0)
void ICACHE_FLASH_ATTR
pwm_start(void) {
uint8 i, j;
PWM_DBG("--Function pwm_start() is called\n");
PWM_DBG("pwm_gpio:%x,pwm_channel_num:%d\n", pwm_gpio, pwm_channel_num);
PWM_DBG("pwm_out_io_num[0]:%d,[1]:%d,[2]:%d\n", pwm_out_io_num[0], pwm_out_io_num[1], pwm_out_io_num[2]);
PWM_DBG("pwm.period:%d,pwm.duty[0]:%d,[1]:%d,[2]:%d\n", pwm.period, pwm.duty[0], pwm.duty[1], pwm.duty[2]);
LOCK_PWM(critical); // enter critical
// if a toggle is pending, we reset it since we're changing the settings again
pwm_toggle_request = 0;
struct pwm_single_param *local_single = pwm_single_toggle[pwm_toggle ^ 0x01];
uint8 *local_channel = &pwm_channel_toggle[pwm_toggle ^ 0x01];
// step 1: init PWM_CHANNEL+1 channels param
for (i = 0; i < pwm_channel_num; i++) {
uint32 us = pwm.period * pwm.duty[i] / PWM_DEPTH;
local_single[i].h_time = US_TO_RTC_TIMER_TICKS(us);
PWM_DBG("i:%d us:%d ht:%d\n", i, us, local_single[i].h_time);
local_single[i].gpio_set = 0;
local_single[i].gpio_clear = 1 << pin_num[pwm_out_io_num[i]];
}
local_single[pwm_channel_num].h_time = US_TO_RTC_TIMER_TICKS(pwm.period);
local_single[pwm_channel_num].gpio_set = pwm_gpio;
local_single[pwm_channel_num].gpio_clear = 0;
PWM_DBG("i:%d period:%d ht:%d\n", pwm_channel_num, pwm.period, local_single[pwm_channel_num].h_time);
// step 2: sort, small to big
pwm_insert_sort(local_single, pwm_channel_num + 1);
*local_channel = pwm_channel_num + 1;
PWM_DBG("1channel:%d,single[0]:%d,[1]:%d,[2]:%d,[3]:%d\n", *local_channel, local_single[0].h_time, local_single[1].h_time, local_single[2].h_time, local_single[3].h_time);
// step 3: combine same duty channels
for (i = pwm_channel_num; i > 0; i--) {
if (local_single[i].h_time == local_single[i - 1].h_time) {
local_single[i - 1].gpio_set |= local_single[i].gpio_set;
local_single[i - 1].gpio_clear |= local_single[i].gpio_clear;
for (j = i + 1; j < *local_channel; j++) {
memcpy(&local_single[j - 1], &local_single[j], sizeof(struct pwm_single_param));
}
(*local_channel)--;
}
}
PWM_DBG("2channel:%d,single[0]:%d,[1]:%d,[2]:%d,[3]:%d\n", *local_channel, local_single[0].h_time, local_single[1].h_time, local_single[2].h_time, local_single[3].h_time);
// step 4: calc delta time
for (i = *local_channel - 1; i > 0; i--) {
local_single[i].h_time -= local_single[i - 1].h_time;
}
// step 5: last channel needs to clean
local_single[*local_channel - 1].gpio_clear = 0;
// step 6: if first channel duty is 0, remove it
if (local_single[0].h_time == 0) {
local_single[*local_channel - 1].gpio_set &= ~local_single[0].gpio_clear;
local_single[*local_channel - 1].gpio_clear |= local_single[0].gpio_clear;
for (i = 1; i < *local_channel; i++) {
memcpy(&local_single[i - 1], &local_single[i], sizeof(struct pwm_single_param));
}
(*local_channel)--;
}
// if timer is down, need to set gpio and start timer
if (pwm_timer_down == 1) {
pwm_channel = local_channel;
pwm_single = local_single;
// start
gpio_output_set(local_single[0].gpio_set, local_single[0].gpio_clear, pwm_gpio, 0);
// do the first toggle because timer has to have a valid set to do it's job
pwm_toggle ^= 0x01;
pwm_timer_down = 0;
RTC_REG_WRITE(FRC1_LOAD_ADDRESS, local_single[0].h_time);
} else {
// request pwm_tim1_intr_handler to swap the timing buffers
pwm_toggle_request = 1;
}
UNLOCK_PWM(critical); // leave critical
PWM_DBG("3channel:%d,single[0]:%d,[1]:%d,[2]:%d,[3]:%d\n", *local_channel, local_single[0].h_time, local_single[1].h_time, local_single[2].h_time, local_single[3].h_time);
}
/******************************************************************************
* FunctionName : pwm_set_duty
* Description : set each channel's duty params
* Parameters : int16_t duty : 0 ~ PWM_DEPTH
* uint8 channel : channel index
* Returns : NONE
*******************************************************************************/
void ICACHE_FLASH_ATTR
pwm_set_duty(int16_t duty, uint8 channel) {
uint8 i;
for (i = 0; i < pwm_channel_num; i++) {
if (pwm_out_io_num[i] == channel) {
channel = i;
break;
}
}
if (i == pwm_channel_num) { // non found
return;
}
LOCK_PWM(critical); // enter critical
if (duty < 1) {
pwm.duty[channel] = 0;
} else if (duty >= PWM_DEPTH) {
pwm.duty[channel] = PWM_DEPTH;
} else {
pwm.duty[channel] = duty;
}
UNLOCK_PWM(critical); // leave critical
}
/******************************************************************************
* FunctionName : pwm_set_freq
* Description : set pwm frequency
* Parameters : uint16 freq : 100hz typically
* Returns : NONE
*******************************************************************************/
void ICACHE_FLASH_ATTR
pwm_set_freq(uint16 freq, uint8 channel) {
LOCK_PWM(critical); // enter critical
if (freq > PWM_FREQ_MAX) {
pwm.freq = PWM_FREQ_MAX;
} else if (freq < 1) {
pwm.freq = 1;
} else {
pwm.freq = freq;
}
pwm.period = PWM_1S / pwm.freq;
UNLOCK_PWM(critical); // leave critical
}
/******************************************************************************
* FunctionName : pwm_get_duty
* Description : get duty of each channel
* Parameters : uint8 channel : channel index
* Returns : NONE
*******************************************************************************/
uint16 ICACHE_FLASH_ATTR
pwm_get_duty(uint8 channel) {
uint8 i;
for (i = 0; i < pwm_channel_num; i++) {
if (pwm_out_io_num[i] == channel) {
channel = i;
break;
}
}
if (i == pwm_channel_num) { // non found
return 0;
}
return pwm.duty[channel];
}
/******************************************************************************
* FunctionName : pwm_get_freq
* Description : get pwm frequency
* Parameters : NONE
* Returns : uint16 : pwm frequency
*******************************************************************************/
uint16 ICACHE_FLASH_ATTR
pwm_get_freq(uint8 channel) {
return pwm.freq;
}
/******************************************************************************
* FunctionName : pwm_period_timer
* Description : pwm period timer function, output high level,
* start each channel's high level timer
* Parameters : NONE
* Returns : NONE
*******************************************************************************/
STATIC void ICACHE_RAM_ATTR
pwm_tim1_intr_handler(void *dummy) {
(void)dummy;
RTC_CLR_REG_MASK(FRC1_INT_ADDRESS, FRC1_INT_CLR_MASK);
if (pwm_current_channel >= (*pwm_channel - 1)) { // *pwm_channel may change outside
if (pwm_toggle_request != 0) {
pwm_toggle ^= 1;
pwm_toggle_request = 0;
}
pwm_single = pwm_single_toggle[pwm_toggle];
pwm_channel = &pwm_channel_toggle[pwm_toggle];
gpio_output_set(pwm_single[*pwm_channel - 1].gpio_set,
pwm_single[*pwm_channel - 1].gpio_clear,
pwm_gpio,
0);
pwm_current_channel = 0;
RTC_REG_WRITE(FRC1_LOAD_ADDRESS, pwm_single[pwm_current_channel].h_time);
} else {
gpio_output_set(pwm_single[pwm_current_channel].gpio_set,
pwm_single[pwm_current_channel].gpio_clear,
pwm_gpio, 0);
pwm_current_channel++;
RTC_REG_WRITE(FRC1_LOAD_ADDRESS, pwm_single[pwm_current_channel].h_time);
}
}
/******************************************************************************
* FunctionName : pwm_init
* Description : pwm gpio, params and timer initialization
* Parameters : uint16 freq : pwm freq param
* uint16 *duty : each channel's duty
* Returns : NONE
*******************************************************************************/
void ICACHE_FLASH_ATTR
pwm_init(void) {
uint8 i;
RTC_REG_WRITE(FRC1_CTRL_ADDRESS, // FRC2_AUTO_RELOAD|
DIVDED_BY_16
| FRC1_ENABLE_TIMER
| TM_EDGE_INT);
RTC_REG_WRITE(FRC1_LOAD_ADDRESS, 0);
for (i = 0; i < PWM_CHANNEL; i++) {
pwm_gpio = 0;
pwm.duty[i] = 0;
}
pwm_set_freq(500, 0);
pwm_start();
ETS_FRC_TIMER1_INTR_ATTACH(pwm_tim1_intr_handler, NULL);
TM1_EDGE_INT_ENABLE();
ETS_FRC1_INTR_ENABLE();
}
int ICACHE_FLASH_ATTR
pwm_add(uint8_t pin_id, uint32_t pin_mux, uint32_t pin_func) {
PWM_DBG("--Function pwm_add() is called. channel:%d\n", channel);
PWM_DBG("pwm_gpio:%x,pwm_channel_num:%d\n", pwm_gpio, pwm_channel_num);
PWM_DBG("pwm_out_io_num[0]:%d,[1]:%d,[2]:%d\n", pwm_out_io_num[0], pwm_out_io_num[1], pwm_out_io_num[2]);
PWM_DBG("pwm.duty[0]:%d,[1]:%d,[2]:%d\n", pwm.duty[0], pwm.duty[1], pwm.duty[2]);
int channel = -1;
for (int i = 0; i < PWM_CHANNEL; ++i) {
if (pin_num[i] == pin_id) {
channel = i;
break;
}
}
if (channel == -1) {
return -1;
}
uint8 i;
for (i = 0; i < PWM_CHANNEL; i++) {
if (pwm_out_io_num[i] == channel) { // already exist
return channel;
}
if (pwm_out_io_num[i] == -1) { // empty exist
LOCK_PWM(critical); // enter critical
pwm_out_io_num[i] = channel;
pwm.duty[i] = 0;
pwm_gpio |= (1 << pin_num[channel]);
PIN_FUNC_SELECT(pin_mux, pin_func);
pwm_channel_num++;
UNLOCK_PWM(critical); // leave critical
return channel;
}
}
return -1;
}
bool ICACHE_FLASH_ATTR
pwm_delete(uint8 channel) {
PWM_DBG("--Function pwm_delete() is called. channel:%d\n", channel);
PWM_DBG("pwm_gpio:%x,pwm_channel_num:%d\n", pwm_gpio, pwm_channel_num);
PWM_DBG("pwm_out_io_num[0]:%d,[1]:%d,[2]:%d\n", pwm_out_io_num[0], pwm_out_io_num[1], pwm_out_io_num[2]);
PWM_DBG("pwm.duty[0]:%d,[1]:%d,[2]:%d\n", pwm.duty[0], pwm.duty[1], pwm.duty[2]);
uint8 i, j;
for (i = 0; i < pwm_channel_num; i++) {
if (pwm_out_io_num[i] == channel) { // exist
LOCK_PWM(critical); // enter critical
pwm_out_io_num[i] = -1;
pwm_gpio &= ~(1 << pin_num[channel]); // clear the bit
for (j = i; j < pwm_channel_num - 1; j++) {
pwm_out_io_num[j] = pwm_out_io_num[j + 1];
pwm.duty[j] = pwm.duty[j + 1];
}
pwm_out_io_num[pwm_channel_num - 1] = -1;
pwm.duty[pwm_channel_num - 1] = 0;
pwm_channel_num--;
UNLOCK_PWM(critical); // leave critical
return true;
}
}
// non found
return true;
}