ledc: fix reported error when div_param == 256

Whenever bit_num and freq_hz are such that div_param == 256, the code would flag that as an error.
In fact, value 256 of div_param was a valid one (HW requires that div_param >= 1.0, when interpreted as a Q10.8 fixed point value).
Changed the if statements a bit to make the logic clearer, and added more descriptive error messages.
Also added missing error for the unimplemented case of low speed mode.
This commit is contained in:
Ivan Grokhotkov 2016-11-24 12:27:32 +08:00
parent 137c027274
commit f60e54497c

View file

@ -137,29 +137,32 @@ esp_err_t ledc_timer_config(ledc_timer_config_t* timer_conf)
return ESP_ERR_INVALID_ARG;
}
if(timer_num > LEDC_TIMER_3) {
ESP_LOGE(LEDC_TAG, "Time Select %u", timer_num);
ESP_LOGE(LEDC_TAG, "invalid timer #%u", timer_num);
return ESP_ERR_INVALID_ARG;
}
esp_err_t ret = ESP_OK;
uint32_t precision = (0x1 << bit_num); //2**depth
uint64_t div_param = ((uint64_t) LEDC_APB_CLK_HZ << 8) / freq_hz / precision; //8bit fragment
int timer_clk_src;
/*Fail ,because the div_num overflow or too small*/
if(div_param <= 256 || div_param > LEDC_DIV_NUM_HSTIMER0_V) { //REF TICK
/*Selet the reference tick*/
uint32_t precision = (0x1 << bit_num); // 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 bit depth can not be achieved, try reducing freq_hz or bit_num. 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, "div param err,div_param=%u", (uint32_t)div_param);
if(div_param < 256 || div_param > LEDC_DIV_NUM_HSTIMER0_V) {
ESP_LOGE(LEDC_TAG, "requested frequency and bit depth can not be achieved, try increasing freq_hz or bit_num. div_param=%d", (uint32_t) div_param);
ret = ESP_FAIL;
}
timer_clk_src = LEDC_REF_TICK;
} else { //APB TICK
timer_clk_src = LEDC_APB_CLK;
}
/*set timer parameters*/
/*timer settings decide the clk of counter and the period of PWM*/
// set timer parameters
ledc_timer_set(speed_mode, timer_num, div_param, bit_num, timer_clk_src);
/* reset timer.*/
// reset timer
ledc_timer_rst(speed_mode, timer_num);
return ret;
}
@ -174,7 +177,8 @@ esp_err_t ledc_set_pin(int gpio_num, ledc_mode_t speed_mode, ledc_channel_t ledc
if(speed_mode == LEDC_HIGH_SPEED_MODE) {
gpio_matrix_out(gpio_num, LEDC_HS_SIG_OUT0_IDX + ledc_channel, 0, 0);
} else {
ESP_LOGE(LEDC_TAG, "low speed mode is not implemented");
return ESP_ERR_NOT_SUPPORTED;
}
return ESP_OK;
}