e32302c1a6
The PWM driver uses a double buffer for the PWM timing array, one in current use and the other one to update when changing duty parameters. The issue was that once the duty parameters were changed the updated buffer was applied immediately without synchronising to the start of the PWM period. By moving the buffer toggling/swapping to the interrupt when the cycle is done there are no more glitches.
427 lines
14 KiB
C
427 lines
14 KiB
C
/******************************************************************************
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* Copyright 2013-2014 Espressif Systems (Wuxi)
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*
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* FileName: pwm.c
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*
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* Description: pwm driver
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*
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* Modification history:
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* 2014/5/1, v1.0 create this file.
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* 2016/3/2: Modifications by dpgeorge to suit MicroPython
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*******************************************************************************/
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#include <stdio.h>
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#include <string.h>
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#include "etshal.h"
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#include "os_type.h"
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#include "gpio.h"
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#include "esppwm.h"
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#include "py/mpprint.h"
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#define PWM_DBG(...)
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// #define PWM_DBG(...) mp_printf(&mp_plat_print, __VA_ARGS__)
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#define ICACHE_RAM_ATTR // __attribute__((section(".text")))
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#define PWM_CHANNEL 8
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#define PWM_DEPTH 1023
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#define PWM_FREQ_MAX 1000
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#define PWM_1S 1000000
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struct pwm_single_param {
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uint16_t gpio_set;
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uint16_t gpio_clear;
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uint32_t h_time;
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};
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struct pwm_param {
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uint32_t period;
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uint16_t freq;
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uint16_t duty[PWM_CHANNEL];
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};
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STATIC const uint8_t pin_num[PWM_CHANNEL] = {0, 2, 4, 5, 12, 13, 14, 15};
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STATIC struct pwm_single_param pwm_single_toggle[2][PWM_CHANNEL + 1];
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STATIC struct pwm_single_param *pwm_single;
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STATIC struct pwm_param pwm;
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STATIC int8_t pwm_out_io_num[PWM_CHANNEL] = {-1, -1, -1, -1, -1, -1, -1, -1};
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STATIC uint8_t pwm_channel_toggle[2];
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STATIC uint8_t *pwm_channel;
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STATIC uint8_t pwm_toggle = 1;
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STATIC uint8_t pwm_timer_down = 1;
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STATIC uint8_t pwm_current_channel = 0;
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STATIC uint16_t pwm_gpio = 0;
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STATIC uint8_t pwm_channel_num = 0;
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STATIC volatile uint8_t pwm_toggle_request = 0;
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// XXX: 0xffffffff/(80000000/16)=35A
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#define US_TO_RTC_TIMER_TICKS(t) \
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((t) ? \
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(((t) > 0x35A) ? \
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(((t) >> 2) * ((APB_CLK_FREQ >> 4) / 250000) + ((t) & 0x3) * ((APB_CLK_FREQ >> 4) / 1000000)) : \
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(((t) * (APB_CLK_FREQ >> 4)) / 1000000)) : \
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0)
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// FRC1
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#define FRC1_ENABLE_TIMER BIT7
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typedef enum {
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DIVDED_BY_1 = 0,
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DIVDED_BY_16 = 4,
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DIVDED_BY_256 = 8,
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} TIMER_PREDIVED_MODE;
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typedef enum {
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TM_LEVEL_INT = 1,
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TM_EDGE_INT = 0,
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} TIMER_INT_MODE;
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STATIC void ICACHE_FLASH_ATTR
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pwm_insert_sort(struct pwm_single_param pwm[], uint8 n) {
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uint8 i;
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for (i = 1; i < n; i++) {
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if (pwm[i].h_time < pwm[i - 1].h_time) {
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int8 j = i - 1;
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struct pwm_single_param tmp;
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memcpy(&tmp, &pwm[i], sizeof(struct pwm_single_param));
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memcpy(&pwm[i], &pwm[i - 1], sizeof(struct pwm_single_param));
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while (tmp.h_time < pwm[j].h_time) {
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memcpy(&pwm[j + 1], &pwm[j], sizeof(struct pwm_single_param));
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j--;
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if (j < 0) {
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break;
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}
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}
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memcpy(&pwm[j + 1], &tmp, sizeof(struct pwm_single_param));
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}
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}
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}
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STATIC volatile uint8 critical = 0;
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#define LOCK_PWM(c) do { \
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while ((c) == 1); \
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(c) = 1; \
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} while (0)
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#define UNLOCK_PWM(c) do { \
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(c) = 0; \
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} while (0)
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void ICACHE_FLASH_ATTR
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pwm_start(void) {
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uint8 i, j;
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PWM_DBG("--Function pwm_start() is called\n");
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PWM_DBG("pwm_gpio:%x,pwm_channel_num:%d\n",pwm_gpio,pwm_channel_num);
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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]);
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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]);
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LOCK_PWM(critical); // enter critical
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// if a toggle is pending, we reset it since we're changing the settings again
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pwm_toggle_request = 0;
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struct pwm_single_param *local_single = pwm_single_toggle[pwm_toggle ^ 0x01];
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uint8 *local_channel = &pwm_channel_toggle[pwm_toggle ^ 0x01];
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// step 1: init PWM_CHANNEL+1 channels param
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for (i = 0; i < pwm_channel_num; i++) {
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uint32 us = pwm.period * pwm.duty[i] / PWM_DEPTH;
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local_single[i].h_time = US_TO_RTC_TIMER_TICKS(us);
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PWM_DBG("i:%d us:%d ht:%d\n",i,us,local_single[i].h_time);
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local_single[i].gpio_set = 0;
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local_single[i].gpio_clear = 1 << pin_num[pwm_out_io_num[i]];
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}
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local_single[pwm_channel_num].h_time = US_TO_RTC_TIMER_TICKS(pwm.period);
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local_single[pwm_channel_num].gpio_set = pwm_gpio;
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local_single[pwm_channel_num].gpio_clear = 0;
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PWM_DBG("i:%d period:%d ht:%d\n",pwm_channel_num,pwm.period,local_single[pwm_channel_num].h_time);
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// step 2: sort, small to big
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pwm_insert_sort(local_single, pwm_channel_num + 1);
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*local_channel = pwm_channel_num + 1;
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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);
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// step 3: combine same duty channels
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for (i = pwm_channel_num; i > 0; i--) {
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if (local_single[i].h_time == local_single[i - 1].h_time) {
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local_single[i - 1].gpio_set |= local_single[i].gpio_set;
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local_single[i - 1].gpio_clear |= local_single[i].gpio_clear;
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for (j = i + 1; j < *local_channel; j++) {
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memcpy(&local_single[j - 1], &local_single[j], sizeof(struct pwm_single_param));
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}
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(*local_channel)--;
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}
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}
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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);
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// step 4: cacl delt time
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for (i = *local_channel - 1; i > 0; i--) {
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local_single[i].h_time -= local_single[i - 1].h_time;
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}
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// step 5: last channel needs to clean
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local_single[*local_channel - 1].gpio_clear = 0;
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// step 6: if first channel duty is 0, remove it
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if (local_single[0].h_time == 0) {
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local_single[*local_channel - 1].gpio_set &= ~local_single[0].gpio_clear;
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local_single[*local_channel - 1].gpio_clear |= local_single[0].gpio_clear;
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for (i = 1; i < *local_channel; i++) {
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memcpy(&local_single[i - 1], &local_single[i], sizeof(struct pwm_single_param));
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}
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(*local_channel)--;
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}
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// if timer is down, need to set gpio and start timer
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if (pwm_timer_down == 1) {
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pwm_channel = local_channel;
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pwm_single = local_single;
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// start
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gpio_output_set(local_single[0].gpio_set, local_single[0].gpio_clear, pwm_gpio, 0);
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// do the first toggle because timer has to have a valid set to do it's job
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pwm_toggle ^= 0x01;
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pwm_timer_down = 0;
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RTC_REG_WRITE(FRC1_LOAD_ADDRESS, local_single[0].h_time);
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} else {
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// request pwm_tim1_intr_handler to swap the timing buffers
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pwm_toggle_request = 1;
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}
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UNLOCK_PWM(critical); // leave critical
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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);
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}
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/******************************************************************************
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* FunctionName : pwm_set_duty
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* Description : set each channel's duty params
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* Parameters : int16_t duty : 0 ~ PWM_DEPTH
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* uint8 channel : channel index
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* Returns : NONE
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*******************************************************************************/
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void ICACHE_FLASH_ATTR
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pwm_set_duty(int16_t duty, uint8 channel) {
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uint8 i;
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for (i = 0; i < pwm_channel_num; i++) {
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if (pwm_out_io_num[i] == channel) {
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channel = i;
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break;
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}
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}
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if (i == pwm_channel_num) { // non found
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return;
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}
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LOCK_PWM(critical); // enter critical
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if (duty < 1) {
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pwm.duty[channel] = 0;
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} else if (duty >= PWM_DEPTH) {
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pwm.duty[channel] = PWM_DEPTH;
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} else {
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pwm.duty[channel] = duty;
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}
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UNLOCK_PWM(critical); // leave critical
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}
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/******************************************************************************
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* FunctionName : pwm_set_freq
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* Description : set pwm frequency
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* Parameters : uint16 freq : 100hz typically
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* Returns : NONE
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*******************************************************************************/
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void ICACHE_FLASH_ATTR
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pwm_set_freq(uint16 freq, uint8 channel) {
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LOCK_PWM(critical); // enter critical
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if (freq > PWM_FREQ_MAX) {
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pwm.freq = PWM_FREQ_MAX;
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} else if (freq < 1) {
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pwm.freq = 1;
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} else {
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pwm.freq = freq;
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}
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pwm.period = PWM_1S / pwm.freq;
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UNLOCK_PWM(critical); // leave critical
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}
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/******************************************************************************
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* FunctionName : pwm_get_duty
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* Description : get duty of each channel
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* Parameters : uint8 channel : channel index
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* Returns : NONE
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*******************************************************************************/
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uint16 ICACHE_FLASH_ATTR
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pwm_get_duty(uint8 channel) {
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uint8 i;
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for (i = 0; i < pwm_channel_num; i++) {
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if (pwm_out_io_num[i] == channel) {
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channel = i;
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break;
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}
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}
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if (i == pwm_channel_num) { // non found
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return 0;
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}
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return pwm.duty[channel];
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}
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/******************************************************************************
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* FunctionName : pwm_get_freq
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* Description : get pwm frequency
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* Parameters : NONE
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* Returns : uint16 : pwm frequency
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*******************************************************************************/
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uint16 ICACHE_FLASH_ATTR
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pwm_get_freq(uint8 channel) {
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return pwm.freq;
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}
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/******************************************************************************
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* FunctionName : pwm_period_timer
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* Description : pwm period timer function, output high level,
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* start each channel's high level timer
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* Parameters : NONE
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* Returns : NONE
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*******************************************************************************/
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STATIC void ICACHE_RAM_ATTR
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pwm_tim1_intr_handler(void *dummy) {
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(void)dummy;
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RTC_CLR_REG_MASK(FRC1_INT_ADDRESS, FRC1_INT_CLR_MASK);
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if (pwm_current_channel >= (*pwm_channel - 1)) { // *pwm_channel may change outside
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if (pwm_toggle_request != 0) {
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pwm_toggle ^= 1;
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pwm_toggle_request = 0;
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}
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pwm_single = pwm_single_toggle[pwm_toggle];
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pwm_channel = &pwm_channel_toggle[pwm_toggle];
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gpio_output_set(pwm_single[*pwm_channel - 1].gpio_set,
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pwm_single[*pwm_channel - 1].gpio_clear,
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pwm_gpio,
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0);
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pwm_current_channel = 0;
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RTC_REG_WRITE(FRC1_LOAD_ADDRESS, pwm_single[pwm_current_channel].h_time);
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} else {
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gpio_output_set(pwm_single[pwm_current_channel].gpio_set,
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pwm_single[pwm_current_channel].gpio_clear,
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pwm_gpio, 0);
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pwm_current_channel++;
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RTC_REG_WRITE(FRC1_LOAD_ADDRESS, pwm_single[pwm_current_channel].h_time);
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}
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}
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/******************************************************************************
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* FunctionName : pwm_init
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* Description : pwm gpio, params and timer initialization
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* Parameters : uint16 freq : pwm freq param
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* uint16 *duty : each channel's duty
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* Returns : NONE
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*******************************************************************************/
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void ICACHE_FLASH_ATTR
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pwm_init(void) {
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uint8 i;
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RTC_REG_WRITE(FRC1_CTRL_ADDRESS, // FRC2_AUTO_RELOAD|
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DIVDED_BY_16
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| FRC1_ENABLE_TIMER
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| TM_EDGE_INT);
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RTC_REG_WRITE(FRC1_LOAD_ADDRESS, 0);
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for (i = 0; i < PWM_CHANNEL; i++) {
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pwm_gpio = 0;
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pwm.duty[i] = 0;
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}
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pwm_set_freq(500, 0);
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pwm_start();
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ETS_FRC_TIMER1_INTR_ATTACH(pwm_tim1_intr_handler, NULL);
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TM1_EDGE_INT_ENABLE();
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ETS_FRC1_INTR_ENABLE();
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}
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int ICACHE_FLASH_ATTR
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pwm_add(uint8_t pin_id, uint32_t pin_mux, uint32_t pin_func) {
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PWM_DBG("--Function pwm_add() is called. channel:%d\n", channel);
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PWM_DBG("pwm_gpio:%x,pwm_channel_num:%d\n",pwm_gpio,pwm_channel_num);
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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]);
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PWM_DBG("pwm.duty[0]:%d,[1]:%d,[2]:%d\n",pwm.duty[0],pwm.duty[1],pwm.duty[2]);
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int channel = -1;
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for (int i = 0; i < PWM_CHANNEL; ++i) {
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if (pin_num[i] == pin_id) {
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channel = i;
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break;
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}
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}
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if (channel == -1) {
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return -1;
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}
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uint8 i;
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for (i = 0; i < PWM_CHANNEL; i++) {
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if (pwm_out_io_num[i] == channel) { // already exist
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return channel;
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}
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if (pwm_out_io_num[i] == -1) { // empty exist
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LOCK_PWM(critical); // enter critical
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pwm_out_io_num[i] = channel;
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pwm.duty[i] = 0;
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pwm_gpio |= (1 << pin_num[channel]);
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PIN_FUNC_SELECT(pin_mux, pin_func);
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GPIO_REG_WRITE(GPIO_PIN_ADDR(GPIO_ID_PIN(pin_num[channel])), GPIO_REG_READ(GPIO_PIN_ADDR(GPIO_ID_PIN(pin_num[channel]))) & (~GPIO_PIN_PAD_DRIVER_SET(GPIO_PAD_DRIVER_ENABLE))); // disable open drain;
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pwm_channel_num++;
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UNLOCK_PWM(critical); // leave critical
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return channel;
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}
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}
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return -1;
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}
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bool ICACHE_FLASH_ATTR
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pwm_delete(uint8 channel) {
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PWM_DBG("--Function pwm_delete() is called. channel:%d\n", channel);
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PWM_DBG("pwm_gpio:%x,pwm_channel_num:%d\n",pwm_gpio,pwm_channel_num);
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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]);
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PWM_DBG("pwm.duty[0]:%d,[1]:%d,[2]:%d\n",pwm.duty[0],pwm.duty[1],pwm.duty[2]);
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uint8 i,j;
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for (i = 0; i < pwm_channel_num; i++) {
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if (pwm_out_io_num[i] == channel) { // exist
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LOCK_PWM(critical); // enter critical
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pwm_out_io_num[i] = -1;
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pwm_gpio &= ~(1 << pin_num[channel]); // clear the bit
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for (j = i; j < pwm_channel_num - 1; j++) {
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pwm_out_io_num[j] = pwm_out_io_num[j + 1];
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pwm.duty[j] = pwm.duty[j + 1];
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}
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pwm_out_io_num[pwm_channel_num - 1] = -1;
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pwm.duty[pwm_channel_num - 1] = 0;
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pwm_channel_num--;
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UNLOCK_PWM(critical); // leave critical
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return true;
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}
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}
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// non found
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return true;
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}
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