cpu/esp32: replace deprecated ADC peripheral driver

Author: gschorcht

cpu/esp32/doc_esp32c3.txt

@@ -80,8 +80,12 @@ total:
 The maximum number of ADC channels #ADC_NUMOF_MAX is 6.
 
 @note
-- ADC2 is also used by the WiFi module. The GPIOs connected to ADC2 are
-  therefore not available as ADC channels if the modules `esp_wifi` or
+- According to the ESP32-C2 Errata Sheet, ADC2 with GPIO5 as ADC channel may
+  not work correctly. By default it is still possible to use it anyway.
+  Set `CONFIG_ADC_ONESHOT_FORCE_USE_ADC2_ON_C3` to 0 if you do not want to use
+  it and want to activate the configuration check for this channel.
+- ADC2 is also used by the WiFi module. GPIO5 connected to ADC2 is
+  therefore not available as ADC channels if the modules `esp_wifi*` or
   `esp_now` are used.
 - Vref can be read with function #adc_line_vref_to_gpio at GPIO5.
 

cpu/esp32/esp-idf/adc/Makefile

@@ -2,9 +2,11 @@ MODULE = esp_idf_adc
 
 # source files to be compiled for this module
 ESP32_SDK_SRC = \
-  components/driver/deprecated/adc_legacy.c \
+  components/esp_adc/adc_cali.c \
+  components/esp_adc/adc_oneshot.c \
   components/esp_hw_support/adc_share_hw_ctrl.c \
   components/hal/adc_hal_common.c \
+  components/hal/adc_oneshot_hal.c \
   components/hal/rtc_io_hal.c \
   components/soc/$(CPU_FAM)/adc_periph.c \
   #
@@ -17,11 +19,21 @@ ifeq (esp32s2,$(CPU_FAM))
   ESP32_SDK_SRC += components/efuse/esp32s2/esp_efuse_rtc_table.c
 endif
 
+ifneq (,$(filter esp32 esp32s2,$(CPU_FAM)))
+  ESP32_SDK_SRC += components/esp_adc/$(CPU_FAM)/adc_cali_line_fitting.c
+else
+  ESP32_SDK_SRC += components/esp_adc/adc_cali_curve_fitting.c
+endif
+
+ifneq (,$(filter esp32h2 esp32s3 esp32c3 esp32c6,$(CPU_FAM)))
+  ESP32_SDK_SRC += components/esp_adc/$(CPU_FAM)/curve_fitting_coefficients.c
+endif
+
 include $(RIOTBASE)/Makefile.base
 
 ESP32_SDK_BIN = $(BINDIR)/$(MODULE)
 
-INCLUDES += -I$(ESP32_SDK_DIR)/components/driver/deprecated
+INCLUDES += -I$(ESP32_SDK_DIR)/components/esp_adc/interface
 
 include ../esp_idf.mk
 include ../esp_idf_cflags.mk

cpu/esp32/include/adc_arch.h

@@ -59,12 +59,12 @@ typedef enum {
 #define ADC_ATTENUATION_11_DB   ADC_ATTENUATION_12_DB
 
 /**
- * @brief   Set the attenuation for the ADC line. Default attenuation is 11 dB.
+ * @brief   Set the attenuation for the ADC line. Default attenuation is 12 dB.
  *
  * For each ADC line, an attenuation of the input signal can be defined
  * separately. This results in different full ranges of the measurable voltage
  * at the input. The attenuation can be set to 0 dB, 3 dB, 6 dB and 12 dB,
- * with 11 dB being the standard attenuation. Since an ADC input is measured
+ * with 12 dB being the standard attenuation. Since an ADC input is measured
  * against a reference voltage Vref of 1.1 V, approximately the following
  * measurement ranges are given when using a corresponding attenuation:
  *
@@ -80,33 +80,51 @@ typedef enum {
  * </center>
  *
  * @note: The reference voltage Vref can vary from ADC unit to ADC unit in
- * the range of 1.0V and 1.2V. The Vref of a unit can be routed with
- * function *adc_vref_to_gpio* to a GPIO pin.
+ * the range of 1.0V and 1.2V. Use function adc_get_vrange to get the voltage
+ * range of samples for the configured attenuation.
  *
  * @param   line    ADC line for which the attenuation is set
- * @param   atten   Attenuation, see type definition of *adc_attenuation_t
+ * @param   atten   Attenuation, see type definition of adc_attenuation_t
  * @return  0       on success
  * @return  -1      on error
  */
 int adc_set_attenuation(adc_t line, adc_atten_t atten);
 
+/**
+ * @brief   Get the voltage range of samples for configured attenution
+ *
+ * After initializing an ADC line or reconfiguring the attenuation of an ADC
+ * line with adc_set_attenuation, the adc_get_vrange can be used to determine
+ * the voltage range in which the raw sample values will lie. You can use these
+ * min and max values to calculate the voltage from the raw sample values.
+ *
+ * @param   line    ADC line
+ * @param   min     voltage for a raw sample value of 0
+ * @param   max     voltage for the maximum raw sample
+ */
+void adc_get_vrange(adc_t line, int *min, int *max);
+
 /**
  * @brief   Output reference voltage of a ADC line to GPIO n
  *
  * The Vref of the ADC unit of the given ADC line is routed to a GPIO pin n.
  * This allows to measure the Vref used by the ADC unit to adjusted the
  * results of the conversions accordingly.
  *
+ * @deprecated The function is not supported any longer, use adc_get_vref to get
+ *             the reference voltage for the configured attenutation.
+ * 
  * @note
  * - The given GPIO must be a valid ADC channel of ADC2 unit.
- * - For ESP32 and ESP32C3, the given ADC line has to be a channel of ADC2 unit.
+ * - For ESP32, only the internal reference voltage of ADC2 is given.
  *
  * @param   line    ADC line for which Vref of its ADC unit is routed to the GPIO
  * @param   gpio    GPIO to which Vref is routed (ADC2 channel GPIOs only)
  *
  * @return  0       on success
  * @return  -1      on error
  */
+__attribute__((__deprecated__))
 int adc_line_vref_to_gpio(adc_t line, gpio_t gpio);
 
 #if defined(CPU_FAM_ESP32)

cpu/esp32/include/adc_arch_private.h

@@ -33,11 +33,12 @@ extern "C" {
 #define RTCIO_GPIO(n)   n           /* n-th RTCIO GPIO */
 #define RTCIO_NA        UINT8_MAX   /* RTCIO pin not available */
 
-#define ADC_UNIT_MAX        ((adc_unit_t)255)                   /* Invalid ADC unit ID */
+#define ADC_UNIT_INV        ((adc_unit_t)255)                   /* Invalid ADC unit ID */
+#define ADC_CHANNEL_INV     SOC_ADC_MAX_CHANNEL_NUM             /* Invalid ADC channel ID */
 
-#define ADC_CHANNEL_MAX     SOC_ADC_MAX_CHANNEL_NUM             /* Invalid ADC channel ID */
 #define ADC1_CHANNEL_MAX    (SOC_ADC_CHANNEL_NUM(ADC_UNIT_1))   /* Number of channels of ADC1 */
 #define ADC2_CHANNEL_MAX    (SOC_ADC_CHANNEL_NUM(ADC_UNIT_2))   /* Number of channels of ADC2 */
+#define ADC_CHANNEL_MAX(u)  ((u == ADC_UNIT_1) ? ADC1_CHANNEL_MAX : ADC2_CHANNEL_MAX)
 
 /**
  * @brief   ADC hardware descriptor (for internal use only)

cpu/esp32/include/sdkconfig_esp32c3.h

@@ -155,6 +155,13 @@ extern "C" {
 #define CONFIG_BT_NIMBLE_COEX_PHY_CODED_TX_RX_TLIM_DIS  1
 #endif
 
+/* According to the ESP32-C3 Errata Sheet ADC2 does not work correctly.
+ * To use ADC2 and GPIO5 as ADC channel, CONFIG_ADC_ONESHOT_FORCE_USE_ADC2_ON_C3
+ * has to be set (default). */
+#ifndef CONFIG_ADC_ONESHOT_FORCE_USE_ADC2_ON_C3
+#define CONFIG_ADC_ONESHOT_FORCE_USE_ADC2_ON_C3         1
+#endif
+
 #ifdef __cplusplus
 }
 #endif