esp_adc: support adc calibration on esp32c2

components/efuse/esp32c2/esp_efuse_rtc_calib.c

@@ -5,14 +5,102 @@
  */
 
 #include <esp_bit_defs.h>
+#include "esp_log.h"
 #include "esp_efuse.h"
 #include "esp_efuse_table.h"
+#include "esp_efuse_rtc_calib.h"
+#include "hal/adc_types.h"
 
 int esp_efuse_rtc_calib_get_ver(void)
 {
-    uint32_t result = 0;
-    esp_efuse_read_field_blob(ESP_EFUSE_BLK_VERSION_MINOR, &result, ESP_EFUSE_BLK_VERSION_MINOR[0]->bit_count); // IDF-5366
-    return result;
+    uint32_t blk_ver_major = 0;
+    esp_efuse_read_field_blob(ESP_EFUSE_BLK_VERSION_MAJOR, &blk_ver_major, ESP_EFUSE_BLK_VERSION_MAJOR[0]->bit_count); // IDF-5366
+
+    uint32_t cali_version = (blk_ver_major == 0) ? ESP_EFUSE_ADC_CALIB_VER : 0;
+    if (!cali_version) {
+        ESP_LOGW("eFuse", "calibration efuse version does not match, set default version to 0");
+    }
+
+    return cali_version;
+}
+
+uint32_t esp_efuse_rtc_calib_get_init_code(int version, uint32_t adc_unit, int atten)
+{
+    assert(version == ESP_EFUSE_ADC_CALIB_VER);
+    assert(atten <= ADC_ATTEN_DB_11);
+    (void) adc_unit;
+
+    if (atten == ADC_ATTEN_DB_2_5 || atten == ADC_ATTEN_DB_6) {
+        /**
+         * - ESP32C2 only supports HW calibration on ADC_ATTEN_DB_0 and ADC_ATTEN_DB_11
+         * - For other attenuation, we just return default value, which is 0.
+         */
+        return 0;
+    }
+
+    int32_t adc_icode_diff_atten0 = 0;
+    int32_t adc_icode_diff_atten3 = 0;
+    int efuse_icode_bits = 0;
+
+    efuse_icode_bits = esp_efuse_get_field_size(ESP_EFUSE_ADC1_INIT_CODE_ATTEN0);
+    ESP_ERROR_CHECK(esp_efuse_read_field_blob(ESP_EFUSE_ADC1_INIT_CODE_ATTEN0, &adc_icode_diff_atten0, efuse_icode_bits));
+    adc_icode_diff_atten0 = ((adc_icode_diff_atten0 & BIT(7)) != 0) ? -(adc_icode_diff_atten0 & 0x7f): adc_icode_diff_atten0;
+
+    efuse_icode_bits = esp_efuse_get_field_size(ESP_EFUSE_ADC1_INIT_CODE_ATTEN3);
+    ESP_ERROR_CHECK(esp_efuse_read_field_blob(ESP_EFUSE_ADC1_INIT_CODE_ATTEN3, &adc_icode_diff_atten3, efuse_icode_bits));
+
+    ESP_EARLY_LOGV("eFuse", "adc_icode_diff_atten0: 0d%"PRId32", adc_icode_diff_atten3: 0d%"PRId32, adc_icode_diff_atten0, adc_icode_diff_atten3);
+
+    uint32_t init_code = 0;
+    if (atten == ADC_ATTEN_DB_0) {
+        init_code = adc_icode_diff_atten0 + 2160;
+    } else {
+        //ADC_ATTEN_DB_11
+        init_code = adc_icode_diff_atten3 + adc_icode_diff_atten0 + 2160;
+    }
+
+    return init_code;
+}
+
+esp_err_t esp_efuse_rtc_calib_get_cal_voltage(int version, uint32_t adc_unit, int atten, uint32_t *out_digi, uint32_t *out_vol_mv)
+{
+    assert(version == ESP_EFUSE_ADC_CALIB_VER);
+    assert(atten <= ADC_ATTEN_DB_11);
+    (void) adc_unit;
+
+    if (atten == ADC_ATTEN_DB_2_5 || atten == ADC_ATTEN_DB_6) {
+        /**
+         * - ESP32C2 only supports SW calibration on ADC_ATTEN_DB_0 and ADC_ATTEN_DB_11
+         * - For other attenuation, we need to return an error, informing upper layer SW calibration driver
+         *   to deal with the error.
+         */
+        return ESP_ERR_INVALID_ARG;
+    }
+
+    int32_t adc_vol_diff_atten0 = 0;
+    int32_t adc_vol_diff_atten3 = 0;
+    int efuse_vol_bits = 0;
+
+    efuse_vol_bits = esp_efuse_get_field_size(ESP_EFUSE_ADC1_CAL_VOL_ATTEN0);
+    ESP_ERROR_CHECK(esp_efuse_read_field_blob(ESP_EFUSE_ADC1_CAL_VOL_ATTEN0, &adc_vol_diff_atten0, efuse_vol_bits));
+    adc_vol_diff_atten0 = ((adc_vol_diff_atten0 & BIT(7)) != 0) ? -(adc_vol_diff_atten0 & 0x7f): adc_vol_diff_atten0;
+
+    efuse_vol_bits = esp_efuse_get_field_size(ESP_EFUSE_ADC1_CAL_VOL_ATTEN3);
+    ESP_ERROR_CHECK(esp_efuse_read_field_blob(ESP_EFUSE_ADC1_CAL_VOL_ATTEN3, &adc_vol_diff_atten3, efuse_vol_bits));
+    adc_vol_diff_atten3 = ((adc_vol_diff_atten3 & BIT(5)) != 0) ? -(adc_vol_diff_atten3 & 0x1f): adc_vol_diff_atten3;
+
+    ESP_EARLY_LOGV("eFuse", "adc_vol_diff_atten0: 0d%"PRId32", adc_vol_diff_atten3: 0d%"PRId32, adc_vol_diff_atten0, adc_vol_diff_atten3);
+
+    if (atten == ADC_ATTEN_DB_0) {
+        *out_digi = adc_vol_diff_atten0 + 1540;
+        *out_vol_mv = 400;
+    } else {
+        //ADC_ATTEN_DB_11
+        *out_digi = adc_vol_diff_atten0 + 1540 - adc_vol_diff_atten3 - 123;
+        *out_vol_mv = 1370;
+    }
+
+    return ESP_OK;
 }
 
 esp_err_t esp_efuse_rtc_calib_get_tsens_val(float* tsens_cal)

components/efuse/esp32c2/include/esp_efuse_rtc_calib.h

@@ -11,6 +11,40 @@
 extern "C" {
 #endif
 
+//This is the ADC calibration value version burnt in efuse
+#define ESP_EFUSE_ADC_CALIB_VER     1
+
+/**
+ * @brief Get the RTC calibration efuse version
+ *
+ * @return Version of the stored efuse
+ */
+int esp_efuse_rtc_calib_get_ver(void);
+
+/**
+ * @brief Get the init code in the efuse, for the corresponding attenuation.
+ *
+ * @param version       Version of the stored efuse
+ * @param adc_unit      ADC unit
+ * @param atten         Attenuation of the init code
+ * @return The init code stored in efuse
+ */
+uint32_t esp_efuse_rtc_calib_get_init_code(int version, uint32_t adc_unit, int atten);
+
+/**
+ * @brief Get the calibration digits stored in the efuse, and the corresponding voltage.
+ *
+ * @param version       Version of the stored efuse
+ * @param adc_unit      ADC unit
+ * @param atten         Attenuation to use
+ * @param out_digi      Output buffer of the digits
+ * @param out_vol_mv    Output of the voltage, in mV
+ * @return
+ *      - ESP_ERR_INVALID_ARG: If `ADC_ATTEN_DB_2_5` or `ADC_ATTEN_DB_6` is used
+ *      - ESP_OK: if success
+ */
+esp_err_t esp_efuse_rtc_calib_get_cal_voltage(int version, uint32_t adc_unit, int atten, uint32_t *out_digi, uint32_t *out_vol_mv);
+
 /**
  * @brief Get the temperature sensor calibration number delta_T stored in the efuse.
  *