adc_i2s: solve the i2s_adc issue when using wifi

components/driver/adc_common.c

@@ -74,6 +74,14 @@ In ADC2, there're two locks used for different cases:
 
 adc2_spinlock should be acquired first, then adc2_wifi_lock or rtc_spinlock.
 */
+// This gets incremented when adc_power_acquire() is called, and decremented when
+// adc_power_release() is called. ADC is powered down when the value reaches zero.
+// Should be modified within critical section (ADC_ENTER/EXIT_CRITICAL).
+static int s_adc_power_on_cnt;
+
+static void adc_power_on_internal(void);
+static void adc_power_off_internal(void);
+
 #ifdef CONFIG_IDF_TARGET_ESP32
 //prevent ADC2 being used by wifi and other tasks at the same time.
 static _lock_t adc2_wifi_lock;
@@ -122,36 +130,60 @@ static uint32_t get_calibration_offset(adc_ll_num_t adc_n, adc_channel_t chan)
 }
 #endif
 
-void adc_power_always_on(void)
+void adc_power_acquire(void)
 {
+    bool powered_on = false;
     ADC_ENTER_CRITICAL();
-    adc_hal_set_power_manage(ADC_POWER_SW_ON);
+    s_adc_power_on_cnt++;
+    if (s_adc_power_on_cnt == 1) {
+        adc_power_on_internal();
+        powered_on = true;
+    }
     ADC_EXIT_CRITICAL();
+    if (powered_on) {
+        ESP_LOGV(ADC_TAG, "%s: ADC powered on", __func__);
+    }
 }
 
-void adc_power_on(void)
+void adc_power_release(void)
+{
+    bool powered_off = false;
+    ADC_ENTER_CRITICAL();
+    s_adc_power_on_cnt--;
+    /* Sanity check */
+    if (s_adc_power_on_cnt < 0) {
+        ADC_EXIT_CRITICAL();
+        ESP_LOGE(ADC_TAG, "%s called, but s_adc_power_on_cnt == 0", __func__);
+        abort();
+    } else if (s_adc_power_on_cnt == 0) {
+        adc_power_off_internal();
+        powered_off = true;
+    }
+    ADC_EXIT_CRITICAL();
+    if (powered_off) {
+        ESP_LOGV(ADC_TAG, "%s: ADC powered off", __func__);
+    }
+}
+
+static void adc_power_on_internal(void)
 {
     ADC_ENTER_CRITICAL();
-    /* The power FSM controlled mode saves more power, while the ADC noise may get increased. */
-#ifndef CONFIG_ADC_FORCE_XPD_FSM
     /* Set the power always on to increase precision. */
     adc_hal_set_power_manage(ADC_POWER_SW_ON);
-#else
-    /* Use the FSM to turn off the power while not used to save power. */
-    if (adc_hal_get_power_manage() != ADC_POWER_BY_FSM) {
-        adc_hal_set_power_manage(ADC_POWER_SW_ON);
-    }
-#endif
     ADC_EXIT_CRITICAL();
 }
 
-void adc_power_off(void)
+void adc_power_on(void) __attribute__((alias("adc_power_on_internal")));
+
+static void adc_power_off_internal(void)
 {
     ADC_ENTER_CRITICAL();
     adc_hal_set_power_manage(ADC_POWER_SW_OFF);
     ADC_EXIT_CRITICAL();
 }
 
+void adc_power_off(void) __attribute__((alias("adc_power_off_internal")));
+
 esp_err_t adc_set_clk_div(uint8_t clk_div)
 {
     ADC_ENTER_CRITICAL();
@@ -337,7 +369,7 @@ int adc1_get_raw(adc1_channel_t channel)
     int adc_value;
     ADC_CHANNEL_CHECK(ADC_NUM_1, channel);
     adc1_rtc_mode_acquire();
-    adc_power_on();
+    adc_power_acquire();
 
 #if CONFIG_IDF_TARGET_ESP32S2 || CONFIG_IDF_TARGET_ESP32S3
     // Get calibration value before going into critical section
@@ -359,6 +391,7 @@ int adc1_get_raw(adc1_channel_t channel)
 #endif
     ADC_EXIT_CRITICAL();
 
+    adc_power_release();
     adc1_lock_release();
     return adc_value;
 }
@@ -371,7 +404,7 @@ int adc1_get_voltage(adc1_channel_t channel)    //Deprecated. Use adc1_get_raw()
 #if SOC_ULP_SUPPORTED
 void adc1_ulp_enable(void)
 {
-    adc_power_on();
+    adc_power_acquire();
 
     ADC_ENTER_CRITICAL();
     adc_hal_set_controller(ADC_NUM_1, ADC_CTRL_ULP);
@@ -492,7 +525,7 @@ esp_err_t adc2_get_raw(adc2_channel_t channel, adc_bits_width_t width_bit, int *
     ADC_CHECK(width_bit == ADC_WIDTH_BIT_13, "WIDTH ERR: ESP32S2 support 13 bit width", ESP_ERR_INVALID_ARG);
 #endif
 
-    adc_power_on();         //in critical section with whole rtc module
+    adc_power_acquire();         //in critical section with whole rtc module
 
 #if CONFIG_IDF_TARGET_ESP32S2 || CONFIG_IDF_TARGET_ESP32S3
     // Get calibration value before going into critical section
@@ -503,6 +536,7 @@ esp_err_t adc2_get_raw(adc2_channel_t channel, adc_bits_width_t width_bit, int *
 
     if ( ADC2_WIFI_LOCK_TRY_ACQUIRE() == -1 ) { //try the lock, return if failed (wifi using).
         ADC2_EXIT_CRITICAL();
+        adc_power_release();
         return ESP_ERR_TIMEOUT;
     }
 #ifdef CONFIG_ADC_DISABLE_DAC
@@ -544,8 +578,12 @@ esp_err_t adc2_get_raw(adc2_channel_t channel, adc_bits_width_t width_bit, int *
 
     if (adc_value < 0) {
         ESP_LOGD( ADC_TAG, "ADC2 ARB: Return data is invalid." );
+        adc_power_release();
         return ESP_ERR_INVALID_STATE;
     }
+
+    //in critical section with whole rtc module
+    adc_power_release();
     *raw_out = adc_value;
     return ESP_OK;
 }
@@ -558,7 +596,9 @@ esp_err_t adc2_vref_to_gpio(gpio_num_t gpio)
 esp_err_t adc_vref_to_gpio(adc_unit_t adc_unit, gpio_num_t gpio)
 {
 #ifdef CONFIG_IDF_TARGET_ESP32
+    adc_power_acquire();
     if (adc_unit & ADC_UNIT_1) {
+        adc_power_release();
         return ESP_ERR_INVALID_ARG;
     }
 #endif
@@ -571,6 +611,7 @@ esp_err_t adc_vref_to_gpio(adc_unit_t adc_unit, gpio_num_t gpio)
         }
     }
     if (ch == ADC2_CHANNEL_MAX) {
+        adc_power_release();
         return ESP_ERR_INVALID_ARG;
     }
 

components/driver/i2s.c

@@ -867,6 +867,13 @@ static esp_err_t i2s_param_config(i2s_port_t i2s_num, const i2s_config_t *i2s_co
     periph_module_enable(i2s_periph_signal[i2s_num].module);
 
 #if SOC_I2S_SUPPORTS_ADC_DAC
+    if(i2s_config->mode & I2S_MODE_ADC_BUILT_IN) {
+        //in ADC built-in mode, we need to call i2s_set_adc_mode to
+        //initialize the specific ADC channel.
+        //in the current stage, we only support ADC1 and single channel mode.
+        //In default data mode, the ADC data is in 12-bit resolution mode.
+        adc_power_acquire();
+    }
 #endif
     // configure I2S data port interface.
     i2s_hal_config_param(&(p_i2s_obj[i2s_num]->hal), i2s_config);

components/driver/include/driver/adc_common.h

@@ -151,14 +151,32 @@ typedef struct adc_digi_init_config_s {
 
 /**
  * @brief Enable ADC power
+ * @deprecated Use adc_power_acquire and adc_power_release instead.
  */
-void adc_power_on(void);
+void adc_power_on(void) __attribute__((deprecated));
 
 /**
  * @brief Power off SAR ADC
- * This function will force power down for ADC
+ * @deprecated Use adc_power_acquire and adc_power_release instead.
+ * This function will force power down for ADC.
+ * This function is deprecated because forcing power ADC power off may
+ * disrupt operation of other components which may be using the ADC.
  */
-void adc_power_off(void);
+void adc_power_off(void) __attribute__((deprecated));
+
+/**
+ * @brief Increment the usage counter for ADC module.
+ * ADC will stay powered on while the counter is greater than 0.
+ * Call adc_power_release when done using the ADC.
+ */
+void adc_power_acquire(void);
+
+/**
+ * @brief Decrement the usage counter for ADC module.
+ * ADC will stay powered on while the counter is greater than 0.
+ * Call this function when done using the ADC.
+ */
+void adc_power_release(void);
 
 /**
  * @brief Initialize ADC pad
@@ -250,6 +268,8 @@ esp_err_t adc1_config_width(adc_bits_width_t width_bit);
  *       the input of GPIO36 and GPIO39 will be pulled down for about 80ns.
  *       When enabling power for any of these peripherals, ignore input from GPIO36 and GPIO39.
  *       Please refer to section 3.11 of 'ECO_and_Workarounds_for_Bugs_in_ESP32' for the description of this issue.
+ *       As a workaround, call adc_power_acquire() in the app. This will result in higher power consumption (by ~1mA),
+ *       but will remove the glitches on GPIO36 and GPIO39.
  *
  * @note Call ``adc1_config_width()`` before the first time this
  *       function is called.
@@ -375,6 +395,9 @@ esp_err_t adc2_config_channel_atten(adc2_channel_t channel, adc_atten_t atten);
  *       the input of GPIO36 and GPIO39 will be pulled down for about 80ns.
  *       When enabling power for any of these peripherals, ignore input from GPIO36 and GPIO39.
  *       Please refer to section 3.11 of 'ECO_and_Workarounds_for_Bugs_in_ESP32' for the description of this issue.
+ *       As a workaround, call adc_power_acquire() in the app. This will result in higher power consumption (by ~1mA),
+ *       but will remove the glitches on GPIO36 and GPIO39.
+ *
  *
  * @note ESP32:
  *       For a given channel, ``adc2_config_channel_atten()``