esp-idf/components/esp_driver_dac/dac_cosine.c

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/*
* SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <string.h>
#include "soc/soc_caps.h"
#include "driver/dac_cosine.h"
#include "hal/clk_tree_ll.h"
#include "dac_priv_common.h"
#include "clk_ctrl_os.h"
#if CONFIG_DAC_ENABLE_DEBUG_LOG
// The local log level must be defined before including esp_log.h
// Set the maximum log level for this source file
#define LOG_LOCAL_LEVEL ESP_LOG_DEBUG
#endif
#include "esp_check.h"
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#if CONFIG_PM_ENABLE
#include "esp_pm.h"
#endif
struct dac_cosine_s {
dac_cosine_config_t cfg; /*!< Cosine mode configurations */
bool is_started; /*!< Flag: is the channel started(not cosine wave generator) */
};
static const char *TAG = "dac_cosine";
/* Cosine wave generator reference count
* The cosine wave generator is shared by dac channels */
static uint32_t s_cwg_refer_cnt = 0;
/* The frequency of cosine wave generator */
static uint32_t s_cwg_freq = 0;
esp_err_t dac_cosine_new_channel(const dac_cosine_config_t *cos_cfg, dac_cosine_handle_t *ret_handle)
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{
#if CONFIG_DAC_ENABLE_DEBUG_LOG
esp_log_level_set(TAG, ESP_LOG_DEBUG);
#endif
/* Parameters validation */
DAC_NULL_POINTER_CHECK(cos_cfg);
DAC_NULL_POINTER_CHECK(ret_handle);
ESP_RETURN_ON_FALSE(cos_cfg->chan_id < SOC_DAC_CHAN_NUM, ESP_ERR_INVALID_ARG, TAG, "invalid dac channel id");
ESP_RETURN_ON_FALSE(cos_cfg->freq_hz >= (130 / clk_ll_rc_fast_get_divider()), ESP_ERR_NOT_SUPPORTED, TAG, "The cosine wave frequency is too low");
ESP_RETURN_ON_FALSE((!s_cwg_freq) || cos_cfg->flags.force_set_freq || (cos_cfg->freq_hz == s_cwg_freq),
ESP_ERR_INVALID_STATE, TAG, "The cosine wave frequency has set already, not allowed to update unless `force_set_freq` is set");
esp_err_t ret = ESP_OK;
/* Allocate cosine handle */
dac_cosine_handle_t handle = heap_caps_calloc(1, sizeof(struct dac_cosine_s), MALLOC_CAP_INTERNAL | MALLOC_CAP_8BIT);
ESP_RETURN_ON_FALSE(handle, ESP_ERR_NO_MEM, TAG, "no memory for the dac cosine handle");
/* Assign configurations */
memcpy(&handle->cfg, cos_cfg, sizeof(dac_cosine_config_t));
/* Register the handle */
ESP_GOTO_ON_ERROR(dac_priv_register_channel(cos_cfg->chan_id, "dac cosine"), err1, TAG, "register dac channel %d failed", cos_cfg->chan_id);
/* Only enabled for getting the correct rtc clock frequency */
periph_rtc_dig_clk8m_enable();
/* Cosine wave generator uses RTC_FAST clock which is divided from RC_FAST */
// [clk_tree] TODO: replace the following calculation with the RTC_FAST frequency getter
uint32_t rtc_clk_freq = periph_rtc_dig_clk8m_get_freq() / clk_ll_rc_fast_get_divider();
/* Disabled after getting the frequency, will re-enabled again when start outputting cosine wave */
periph_rtc_dig_clk8m_disable();
if (rtc_clk_freq == 0) {
ESP_LOGW(TAG, "RTC clock calibration failed, using the approximate value as default");
rtc_clk_freq = SOC_CLK_RC_FAST_FREQ_APPROX;
}
DAC_RTC_ENTER_CRITICAL();
/* Set coefficients for cosine wave generator */
if ((!s_cwg_freq) || cos_cfg->flags.force_set_freq) {
dac_ll_cw_set_freq(cos_cfg->freq_hz, rtc_clk_freq);
s_cwg_freq = cos_cfg->freq_hz;
}
dac_ll_cw_set_atten(cos_cfg->chan_id, cos_cfg->atten);
dac_ll_cw_set_phase(cos_cfg->chan_id, cos_cfg->phase);
dac_ll_cw_set_dc_offset(cos_cfg->chan_id, cos_cfg->offset);
DAC_RTC_EXIT_CRITICAL();
*ret_handle = handle;
return ret;
err1:
free(handle);
return ret;
}
esp_err_t dac_cosine_del_channel(dac_cosine_handle_t handle)
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{
DAC_NULL_POINTER_CHECK(handle);
ESP_RETURN_ON_FALSE(!handle->is_started, ESP_ERR_INVALID_STATE, TAG,
"the dac cosine generator is not stopped yet");
ESP_RETURN_ON_ERROR(dac_priv_deregister_channel(handle->cfg.chan_id), TAG,
"deregister dac channel %d failed", handle->cfg.chan_id);
/* Clear the frequency if no channel using it */
if (!s_cwg_refer_cnt) {
s_cwg_freq = 0;
}
free(handle);
return ESP_OK;
}
esp_err_t dac_cosine_start(dac_cosine_handle_t handle)
{
DAC_NULL_POINTER_CHECK(handle);
ESP_RETURN_ON_FALSE(!handle->is_started, ESP_ERR_INVALID_STATE, TAG,
"the dac channel has already started");
/* Acquire the RTC clock */
periph_rtc_dig_clk8m_enable();
/* Enabled DAC channel */
ESP_RETURN_ON_ERROR(dac_priv_enable_channel(handle->cfg.chan_id), TAG,
"enable dac channel %d failed", handle->cfg.chan_id);
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/* Enabled the cosine wave generator if no channel using it before */
DAC_RTC_ENTER_CRITICAL();
if (s_cwg_refer_cnt == 0) {
dac_ll_cw_generator_enable();
}
/* Connect the DAC channel to the cosine wave generator */
dac_ll_cw_enable_channel(handle->cfg.chan_id, true);
s_cwg_refer_cnt++;
handle->is_started = true;
DAC_RTC_EXIT_CRITICAL();
return ESP_OK;
}
esp_err_t dac_cosine_stop(dac_cosine_handle_t handle)
{
DAC_NULL_POINTER_CHECK(handle);
ESP_RETURN_ON_FALSE(handle->is_started, ESP_ERR_INVALID_STATE, TAG,
"the dac channel has already stopped");
/* Enabled DAC channel */
ESP_RETURN_ON_ERROR(dac_priv_disable_channel(handle->cfg.chan_id), TAG,
"disable dac channel %d failed", handle->cfg.chan_id);
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DAC_RTC_ENTER_CRITICAL();
/* Disconnect the DAC channel from the cosine wave generator */
dac_ll_cw_enable_channel(handle->cfg.chan_id, false);
s_cwg_refer_cnt--;
/* Disable the cosine wave generator if no channel using it */
if (s_cwg_refer_cnt == 0) {
dac_ll_cw_generator_disable();
}
handle->is_started = false;
DAC_RTC_EXIT_CRITICAL();
/* Release the RTC clock */
periph_rtc_dig_clk8m_disable();
return ESP_OK;
}