#include "soc/gpio_periph.h"
#include "driver/ledc.h"
#include "soc/ledc_periph.h"
+#include "soc/rtc.h"
#include "esp_log.h"
static const char* LEDC_TAG = "ledc";
#define LEDC_VAL_NO_CHANGE (-1)
#define LEDC_STEP_NUM_MAX (1023)
#define LEDC_DUTY_DECIMAL_BIT_NUM (4)
+#define DELAY_CLK8M_CLK_SWITCH (5)
+#define SLOW_CLK_CYC_CALIBRATE (13)
#define LEDC_HPOINT_VAL_MAX (LEDC_HPOINT_HSCH1_V)
#define LEDC_FADE_TOO_SLOW_STR "LEDC FADE TOO SLOW"
#define LEDC_FADE_TOO_FAST_STR "LEDC FADE TOO FAST"
static const char *LEDC_FADE_SERVICE_ERR_STR = "LEDC fade service not installed";
static const char *LEDC_FADE_INIT_ERROR_STR = "LEDC fade channel init error, not enough memory or service not installed";
+//This value will be calibrated when in use.
+static uint32_t s_ledc_slow_clk_8M = 0;
+
static void ledc_ls_timer_update(ledc_mode_t speed_mode, ledc_timer_t timer_sel)
{
if (speed_mode == LEDC_LOW_SPEED_MODE) {
}
}
+//We know that CLK8M is about 8M, but don't know the actual value. So we need to do a calibration.
+static bool ledc_slow_clk_calibrate(void)
+{
+ //Enable CLK8M for LEDC
+ SET_PERI_REG_MASK(RTC_CNTL_CLK_CONF_REG, RTC_CNTL_DIG_CLK8M_EN_M);
+ //Waiting for CLK8M to turn on
+ ets_delay_us(DELAY_CLK8M_CLK_SWITCH);
+ uint32_t cal_val = rtc_clk_cal(RTC_CAL_8MD256, SLOW_CLK_CYC_CALIBRATE);
+ if(cal_val == 0) {
+ ESP_LOGE(LEDC_TAG, "CLK8M_CLK calibration failed");
+ return false;
+ }
+ s_ledc_slow_clk_8M = 1000000ULL * (1 << RTC_CLK_CAL_FRACT) * 256 / cal_val;
+ ESP_LOGD(LEDC_TAG, "Calibrate CLK8M_CLK : %d Hz", s_ledc_slow_clk_8M);
+ return true;
+}
+
static esp_err_t ledc_enable_intr_type(ledc_mode_t speed_mode, uint32_t channel, ledc_intr_type_t type)
{
LEDC_ARG_CHECK(speed_mode < LEDC_SPEED_MODE_MAX, "speed_mode");
return ret;
}
+// Setting the LEDC timer divisor with the given source clock, frequency and resolution.
+static esp_err_t ledc_set_timer_div(ledc_mode_t speed_mode, ledc_timer_t timer_num, ledc_clk_cfg_t clk_cfg, int freq_hz, int duty_resolution)
+{
+ uint32_t div_param = 0;
+ uint32_t precision = ( 0x1 << duty_resolution );
+ ledc_clk_src_t timer_clk_src = LEDC_APB_CLK;
+
+ // Calculate the divisor
+ // User specified source clock(RTC8M_CLK) for low speed channel
+ if ((speed_mode == LEDC_LOW_SPEED_MODE) && (clk_cfg == LEDC_USE_RTC8M_CLK)) {
+ if(s_ledc_slow_clk_8M == 0) {
+ if (ledc_slow_clk_calibrate() == false) {
+ goto error;
+ }
+ }
+ div_param = ( (uint64_t) s_ledc_slow_clk_8M << 8 ) / freq_hz / precision;
+ } else {
+ // Automatically select APB or REF_TICK as the source clock.
+ if (clk_cfg == LEDC_AUTO_CLK) {
+ // Try calculating divisor based on LEDC_APB_CLK
+ div_param = ( (uint64_t) LEDC_APB_CLK_HZ << 8 ) / freq_hz / precision;
+ if (div_param > LEDC_DIV_NUM_HSTIMER0_V) {
+ // APB_CLK results in divisor which too high. Try using REF_TICK as clock source.
+ timer_clk_src = LEDC_REF_TICK;
+ div_param = ((uint64_t) LEDC_REF_CLK_HZ << 8) / freq_hz / precision;
+ } else if (div_param < 256) {
+ // divisor is too low
+ goto error;
+ }
+ // User specified source clock(LEDC_APB_CLK_HZ or LEDC_REF_TICK)
+ } else {
+ timer_clk_src = (clk_cfg == LEDC_USE_APB_CLK) ? LEDC_APB_CLK : LEDC_REF_TICK;
+ uint32_t sclk_freq = (clk_cfg == LEDC_USE_APB_CLK) ? LEDC_APB_CLK_HZ : LEDC_REF_CLK_HZ;
+ div_param = ( (uint64_t) sclk_freq << 8 ) / freq_hz / precision;
+ }
+ }
+ if (div_param < 256 || div_param > LEDC_DIV_NUM_LSTIMER0_V) {
+ goto error;
+ }
+ // For low speed channels, if RTC_8MCLK is used as the source clock, the `slow_clk_sel` register should be cleared, otherwise it should be set.
+ if (speed_mode == LEDC_LOW_SPEED_MODE) {
+ LEDC.conf.slow_clk_sel = (clk_cfg == LEDC_USE_RTC8M_CLK) ? 0 : 1;
+ }
+ //Set the divisor
+ ledc_timer_set(speed_mode, timer_num, div_param, duty_resolution, timer_clk_src);
+ // reset the timer
+ ledc_timer_rst(speed_mode, timer_num);
+ return ESP_OK;
+error:
+ ESP_LOGE(LEDC_TAG, "requested frequency and duty resolution can not be achieved, try reducing freq_hz or duty_resolution. div_param=%d",
+ (uint32_t ) div_param);
+ return ESP_FAIL;
+}
+
esp_err_t ledc_timer_config(const ledc_timer_config_t* timer_conf)
{
LEDC_ARG_CHECK(timer_conf != NULL, "timer_conf");
uint32_t timer_num = timer_conf->timer_num;
uint32_t speed_mode = timer_conf->speed_mode;
LEDC_ARG_CHECK(speed_mode < LEDC_SPEED_MODE_MAX, "speed_mode");
+ LEDC_ARG_CHECK(!((timer_conf->clk_cfg == LEDC_USE_RTC8M_CLK) && (speed_mode != LEDC_LOW_SPEED_MODE)), "Only low speed channel support RTC8M_CLK");
periph_module_enable(PERIPH_LEDC_MODULE);
if (freq_hz == 0 || duty_resolution == 0 || duty_resolution >= LEDC_TIMER_BIT_MAX) {
ESP_LOGE(LEDC_TAG, "freq_hz=%u duty_resolution=%u", freq_hz, duty_resolution);
ESP_LOGE(LEDC_TAG, "invalid timer #%u", timer_num);
return ESP_ERR_INVALID_ARG;
}
- esp_err_t ret = ESP_OK;
- uint32_t precision = ( 0x1 << duty_resolution ); // 2**depth
- // Try calculating divisor based on LEDC_APB_CLK
- ledc_clk_src_t timer_clk_src = LEDC_APB_CLK;
- // div_param is a Q10.8 fixed point value
- uint64_t div_param = ( (uint64_t) LEDC_APB_CLK_HZ << 8 ) / freq_hz / precision;
- if (div_param < 256) {
- // divisor is too low
- ESP_LOGE(LEDC_TAG, "requested frequency and duty resolution can not be achieved, try reducing freq_hz or duty_resolution. div_param=%d",
- (uint32_t ) div_param);
- ret = ESP_FAIL;
- }
- if (div_param > LEDC_DIV_NUM_HSTIMER0_V) {
- // APB_CLK results in divisor which too high. Try using REF_TICK as clock source.
- timer_clk_src = LEDC_REF_TICK;
- div_param = ((uint64_t) LEDC_REF_CLK_HZ << 8) / freq_hz / precision;
- if (div_param < 256 || div_param > LEDC_DIV_NUM_HSTIMER0_V) {
- ESP_LOGE(LEDC_TAG, "requested frequency and duty resolution can not be achieved, try increasing freq_hz or duty_resolution. div_param=%d",
- (uint32_t ) div_param);
- ret = ESP_FAIL;
- }
- } else {
- if (speed_mode == LEDC_LOW_SPEED_MODE) {
- //for now, we only select 80mhz for slow clk of LEDC low speed channels.
- LEDC.conf.slow_clk_sel = 1;
- }
- }
- // set timer parameters
- ledc_timer_set(speed_mode, timer_num, div_param, duty_resolution, timer_clk_src);
- // reset timer
- ledc_timer_rst(speed_mode, timer_num);
- return ret;
+ return ledc_set_timer_div(timer_num, timer_num, timer_conf->clk_cfg, freq_hz, duty_resolution);
}
esp_err_t ledc_set_pin(int gpio_num, ledc_mode_t speed_mode, ledc_channel_t ledc_channel)
.bit_num = timer_bit,
.timer_num = timer,
.freq_hz = 5000,
+ .clk_cfg = LEDC_AUTO_CLK,
};
TEST_ESP_OK(ledc_channel_config(&ledc_ch_config));
TEST_ESP_OK(ledc_timer_config(&ledc_time_config));
.bit_num = timer_bit,
.timer_num = timer,
.freq_hz = 5000,
+ .clk_cfg = LEDC_AUTO_CLK,
};
TEST_ESP_OK(ledc_channel_config(&ledc_ch_config));
TEST_ESP_OK(ledc_timer_config(&ledc_time_config));
ledc_time_config.duty_resolution = LEDC_TIMER_13_BIT;
ledc_time_config.timer_num = LEDC_TIMER_0;
ledc_time_config.freq_hz = 5000;
+ ledc_time_config.clk_cfg = LEDC_AUTO_CLK;
ledc_timer_config_t temp_timer_config = ledc_time_config;
TEST_ESP_OK(ledc_timer_config(&ledc_time_config));
.bit_num = LEDC_TIMER_13_BIT,
.timer_num = LEDC_TIMER_0,
.freq_hz = 5000,
+ .clk_cfg = LEDC_AUTO_CLK,
};
ledc_timer_config_t temp_time_config = ledc_time_config;
.bit_num = 13,
.timer_num = LEDC_TIMER_0,
.freq_hz = 5000,
+ .clk_cfg = LEDC_AUTO_CLK,
};
TEST_ESP_OK(ledc_timer_config(&ledc_time_config));
.duty_resolution = LEDC_TIMER_13_BIT,
.timer_num = LEDC_TIMER_0,
.freq_hz = 5000,
+ .clk_cfg = LEDC_AUTO_CLK,
};
TEST_ESP_OK(ledc_timer_config(&ledc_time_config));
.duty_resolution = LEDC_TIMER_13_BIT,
.timer_num = LEDC_TIMER_0,
.freq_hz = 5000,
+ .clk_cfg = LEDC_AUTO_CLK,
};
TEST_ESP_OK(ledc_timer_config(&ledc_time_config));
.duty_resolution = LEDC_TIMER_13_BIT,
.timer_num = LEDC_TIMER_0,
.freq_hz = 5000,
+ .clk_cfg = LEDC_AUTO_CLK,
};
TEST_ESP_OK(ledc_timer_config(&ledc_time_config));
.duty_resolution = LEDC_TIMER_13_BIT,
.timer_num = LEDC_TIMER_0,
.freq_hz = 5000,
+ .clk_cfg = LEDC_AUTO_CLK,
};
TEST_ESP_OK(ledc_timer_config(&ledc_time_config));
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