esp_adc: added adc digital filter feature

components/esp_adc/include/esp_adc/adc_continuous.h

@@ -16,7 +16,6 @@
 extern "C" {
 #endif
 
-#if SOC_ADC_DMA_SUPPORTED
 
 /**
  * @brief Driver Backgrounds
@@ -130,7 +129,7 @@ esp_err_t adc_continuous_config(adc_continuous_handle_t handle, const adc_contin
 /**
  * @brief Register callbacks
  *
- * @note User can deregister a previously registered callback by calling this function and setting the to-be-deregistered callback member int
+ * @note User can deregister a previously registered callback by calling this function and setting the to-be-deregistered callback member in
  *       the `cbs` structure to NULL.
  * @note When CONFIG_ADC_CONTINUOUS_ISR_IRAM_SAFE is enabled, the callback itself and functions called by it should be placed in IRAM.
  *       Involved variables (including `user_data`) should be in internal RAM as well.
@@ -224,8 +223,6 @@ esp_err_t adc_continuous_io_to_channel(int io_num, adc_unit_t *unit_id, adc_chan
  */
 esp_err_t adc_continuous_channel_to_io(adc_unit_t unit_id, adc_channel_t channel, int *io_num);
 
-#endif  //  #if SOC_ADC_DMA_SUPPORTED
-
 
 #ifdef __cplusplus
 }

components/esp_adc/include/esp_adc/adc_filter.h

@@ -0,0 +1,88 @@
+/*
+ * SPDX-FileCopyrightText: 2023 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#pragma once
+
+#include <stdbool.h>
+#include <stdint.h>
+#include "sdkconfig.h"
+#include "esp_err.h"
+#include "esp_adc/adc_continuous.h"
+#include "hal/adc_types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief Type of adc iir filter handle
+ */
+typedef struct adc_iir_filter_t *adc_iir_filter_handle_t;
+
+/**
+ * @brief Filter Configuration
+ */
+typedef struct {
+    adc_unit_t unit;                    ///< ADC unit
+    adc_channel_t channel;              ///< An ADC channel to be filtered. Note for ESP32S2, you should only set only one channel in pattern table, per ADC unit. See programming guide for more details.
+    adc_digi_iir_filter_coeff_t coeff;  ///< ADC filter coefficient
+} adc_continuous_iir_filter_config_t;
+
+
+/**
+ * @brief New a ADC continuous mode IIR filter
+ *
+ * @param[in]   handle   ADC continuous mode driver handle
+ * @param[in]   config   Filter configuration
+ * @param[out]  ret_hdl  Returned IIR filter handle
+ *
+ * @return
+ *        - ESP_OK
+ *        - ESP_ERR_INVALID_ARG:    Invalid argument
+ *        - ESP_ERR_INVALID_STATE:  Invalid state
+ *        - ESP_ERR_NO_MEM:         No memory
+ */
+esp_err_t adc_new_continuous_iir_filter(adc_continuous_handle_t handle, const adc_continuous_iir_filter_config_t *config, adc_iir_filter_handle_t *ret_hdl);
+
+/**
+ * @brief Enable an IIR filter
+ *
+ * @param[in] filter_hdl  ADC IIR filter handle
+ *
+ * @return
+ *        - ESP_OK
+ *        - ESP_ERR_INVALID_ARG:    Invalid argument
+ *        - ESP_ERR_INVALID_STATE:  Invalid state
+ */
+esp_err_t adc_continuous_iir_filter_enable(adc_iir_filter_handle_t filter_hdl);
+
+/**
+ * @brief Disable an IIR filter
+ *
+ * @param[in] filter_hdl  ADC IIR filter handle
+ *
+ * @return
+ *        - ESP_OK
+ *        - ESP_ERR_INVALID_ARG:    Invalid argument
+ *        - ESP_ERR_INVALID_STATE:  Invalid state
+ */
+esp_err_t adc_continuous_iir_filter_disable(adc_iir_filter_handle_t filter_hdl);
+
+/**
+ * @brief Delete the IIR filter
+ *
+ * @param[in] filter_hdl  ADC IIR filter handle
+ *
+ * @return
+ *        - ESP_OK
+ *        - ESP_ERR_INVALID_ARG:    Invalid argument
+ *        - ESP_ERR_INVALID_STATE:  Invalid state
+ */
+esp_err_t adc_del_continuous_iir_filter(adc_iir_filter_handle_t filter_hdl);
+
+#ifdef __cplusplus
+}
+#endif