diff --git a/platforms/chibios/drivers/analog.c b/platforms/chibios/drivers/analog.c
index bf84ce8f76..fb146df936 100644
--- a/platforms/chibios/drivers/analog.c
+++ b/platforms/chibios/drivers/analog.c
@@ -31,7 +31,15 @@
#endif
#if STM32_ADCV3_OVERSAMPLING
-# error "STM32 ADCV3 Oversampling is not supported at this time."
+// Apparently all ADCV3 chips that support oversampling (STM32L4xx, STM32L4xx+,
+// STM32G4xx, STM32WB[35]x) have errata like “Wrong ADC result if conversion
+// done late after calibration or previous conversion”; the workaround is to
+// perform a dummy conversion and discard its result. STM32G4xx chips also
+// have the “ADC channel 0 converted instead of the required ADC channel”
+// errata, one workaround for which is also to perform a dummy conversion.
+# define ADC_DUMMY_CONVERSIONS_AT_START 1
+#else
+# define ADC_DUMMY_CONVERSIONS_AT_START 0
#endif
// Otherwise assume V3
@@ -76,8 +84,10 @@
#ifndef ADC_COUNT
# if defined(RP2040) || defined(STM32F0XX) || defined(STM32F1XX) || defined(STM32F4XX) || defined(GD32VF103) || defined(WB32F3G71xx) || defined(WB32FQ95xx)
# define ADC_COUNT 1
-# elif defined(STM32F3XX)
+# elif defined(STM32F3XX) || defined(STM32G4XX)
# define ADC_COUNT 4
+# elif defined(STM32L4XX)
+# define ADC_COUNT 3
# else
# error "ADC_COUNT has not been set for this ARM microcontroller."
# endif
@@ -89,13 +99,24 @@
# error "The ARM ADC implementation currently only supports reading one channel at a time."
#endif
+// Add dummy conversions as extra channels (this would work only on chips that
+// have multiple channel index fields instead of a channel mask, but all chips
+// that need that workaround are like that).
+#define ADC_TOTAL_CHANNELS (ADC_DUMMY_CONVERSIONS_AT_START + ADC_NUM_CHANNELS)
+
#ifndef ADC_BUFFER_DEPTH
# define ADC_BUFFER_DEPTH 1
#endif
// For more sampling rate options, look at hal_adc_lld.h in ChibiOS
-#ifndef ADC_SAMPLING_RATE
-# define ADC_SAMPLING_RATE ADC_SMPR_SMP_1P5
+#if !defined(ADC_SAMPLING_RATE) && !defined(RP2040)
+# if defined(ADC_SMPR_SMP_1P5)
+# define ADC_SAMPLING_RATE ADC_SMPR_SMP_1P5
+# elif defined(ADC_SMPR_SMP_2P5) // STM32L4XX, STM32L4XXP, STM32G4XX, STM32WBXX
+# define ADC_SAMPLING_RATE ADC_SMPR_SMP_2P5
+# else
+# error "Cannot determine the default ADC_SAMPLING_RATE for this MCU."
+# endif
#endif
// Options are 12, 10, 8, and 6 bit.
@@ -108,7 +129,7 @@
#endif
static ADCConfig adcCfg = {};
-static adcsample_t sampleBuffer[ADC_NUM_CHANNELS * ADC_BUFFER_DEPTH];
+static adcsample_t sampleBuffer[ADC_TOTAL_CHANNELS * ADC_BUFFER_DEPTH];
// Initialize to max number of ADCs, set to empty object to initialize all to false.
static bool adcInitialized[ADC_COUNT] = {};
@@ -116,7 +137,7 @@ static bool adcInitialized[ADC_COUNT] = {};
// TODO: add back TR handling???
static ADCConversionGroup adcConversionGroup = {
.circular = FALSE,
- .num_channels = (uint16_t)(ADC_NUM_CHANNELS),
+ .num_channels = (uint16_t)(ADC_TOTAL_CHANNELS),
#if defined(USE_ADCV1)
.cfgr1 = ADC_CFGR1_CONT | ADC_RESOLUTION,
.smpr = ADC_SAMPLING_RATE,
@@ -240,6 +261,74 @@ __attribute__((weak)) adc_mux pinToMux(pin_t pin) {
case C5: return TO_MUX( ADC_CHANNEL_IN15, 0 );
// STM32F103x[C-G] in 144-pin packages also have analog inputs on F6...F10, but they are on ADC3, and the
// ChibiOS ADC driver for STM32F1xx currently supports only ADC1, therefore these pins are not usable.
+#elif defined(STM32L4XX)
+ case A0: return TO_MUX( ADC_CHANNEL_IN5, 0 ); // Can also be ADC2 in some cases
+ case A1: return TO_MUX( ADC_CHANNEL_IN6, 0 ); // Can also be ADC2 in some cases
+ case A2: return TO_MUX( ADC_CHANNEL_IN7, 0 ); // Can also be ADC2
+ case A3: return TO_MUX( ADC_CHANNEL_IN8, 0 ); // Can also be ADC2
+ case A4: return TO_MUX( ADC_CHANNEL_IN9, 0 ); // Can also be ADC2
+ case A5: return TO_MUX( ADC_CHANNEL_IN10, 0 ); // Can also be ADC2
+ case A6: return TO_MUX( ADC_CHANNEL_IN11, 0 ); // Can also be ADC2
+ case A7: return TO_MUX( ADC_CHANNEL_IN12, 0 ); // Can also be ADC2
+ case B0: return TO_MUX( ADC_CHANNEL_IN15, 0 ); // Can also be ADC2
+ case B1: return TO_MUX( ADC_CHANNEL_IN16, 0 ); // Can also be ADC2
+ case C0: return TO_MUX( ADC_CHANNEL_IN1, 0 ); // Can also be ADC2 or ADC3
+ case C1: return TO_MUX( ADC_CHANNEL_IN2, 0 ); // Can also be ADC2 or ADC3
+ case C2: return TO_MUX( ADC_CHANNEL_IN3, 0 ); // Can also be ADC2 or ADC3
+ case C3: return TO_MUX( ADC_CHANNEL_IN4, 0 ); // Can also be ADC2 or ADC3
+ case C4: return TO_MUX( ADC_CHANNEL_IN13, 0 ); // Can also be ADC2
+ case C5: return TO_MUX( ADC_CHANNEL_IN14, 0 ); // Can also be ADC2
+# if STM32_HAS_GPIOF && STM32_ADC_USE_ADC3
+ case F3: return TO_MUX( ADC_CHANNEL_IN6, 2 );
+ case F4: return TO_MUX( ADC_CHANNEL_IN7, 2 );
+ case F5: return TO_MUX( ADC_CHANNEL_IN8, 2 );
+ case F6: return TO_MUX( ADC_CHANNEL_IN9, 2 );
+ case F7: return TO_MUX( ADC_CHANNEL_IN10, 2 );
+ case F8: return TO_MUX( ADC_CHANNEL_IN11, 2 );
+ case F9: return TO_MUX( ADC_CHANNEL_IN12, 2 );
+ case F10: return TO_MUX( ADC_CHANNEL_IN13, 2 );
+# endif
+#elif defined(STM32G4XX)
+ case A0: return TO_MUX( ADC_CHANNEL_IN1, 0 ); // Can also be ADC2
+ case A1: return TO_MUX( ADC_CHANNEL_IN2, 0 ); // Can also be ADC2
+ case A2: return TO_MUX( ADC_CHANNEL_IN3, 0 );
+ case A3: return TO_MUX( ADC_CHANNEL_IN4, 0 );
+ case A4: return TO_MUX( ADC_CHANNEL_IN17, 1 );
+ case A5: return TO_MUX( ADC_CHANNEL_IN13, 1 );
+ case A6: return TO_MUX( ADC_CHANNEL_IN3, 1 );
+ case A7: return TO_MUX( ADC_CHANNEL_IN4, 1 );
+ case B0: return TO_MUX( ADC_CHANNEL_IN15, 0 ); // Can also be ADC3
+ case B1: return TO_MUX( ADC_CHANNEL_IN12, 0 ); // Can also be ADC3
+ case B2: return TO_MUX( ADC_CHANNEL_IN12, 1 );
+ case B11: return TO_MUX( ADC_CHANNEL_IN14, 0 ); // Can also be ADC2
+ case B12: return TO_MUX( ADC_CHANNEL_IN11, 0 ); // Can also be ADC4
+ case B13: return TO_MUX( ADC_CHANNEL_IN5, 2 );
+ case B14: return TO_MUX( ADC_CHANNEL_IN5, 0 ); // Can also be ADC4
+ case B15: return TO_MUX( ADC_CHANNEL_IN15, 1 ); // Can also be ADC4
+ case C0: return TO_MUX( ADC_CHANNEL_IN6, 0 ); // Can also be ADC2
+ case C1: return TO_MUX( ADC_CHANNEL_IN7, 0 ); // Can also be ADC2
+ case C2: return TO_MUX( ADC_CHANNEL_IN8, 0 ); // Can also be ADC2
+ case C3: return TO_MUX( ADC_CHANNEL_IN9, 0 ); // Can also be ADC2
+ case C4: return TO_MUX( ADC_CHANNEL_IN5, 1 );
+ case C5: return TO_MUX( ADC_CHANNEL_IN11, 1 );
+ case D8: return TO_MUX( ADC_CHANNEL_IN12, 3 );
+ case D9: return TO_MUX( ADC_CHANNEL_IN13, 3 );
+ case D10: return TO_MUX( ADC_CHANNEL_IN7, 2 ); // Can also be ADC4
+ case D11: return TO_MUX( ADC_CHANNEL_IN8, 2 ); // Can also be ADC4
+ case D12: return TO_MUX( ADC_CHANNEL_IN9, 2 ); // Can also be ADC4
+ case D13: return TO_MUX( ADC_CHANNEL_IN10, 2 ); // Can also be ADC4
+ case D14: return TO_MUX( ADC_CHANNEL_IN11, 2 ); // Can also be ADC4
+ case E5: return TO_MUX( ADC_CHANNEL_IN2, 3 );
+ case E7: return TO_MUX( ADC_CHANNEL_IN4, 2 );
+ case E8: return TO_MUX( ADC_CHANNEL_IN6, 2 ); // Can also be ADC4
+ case E9: return TO_MUX( ADC_CHANNEL_IN2, 2 );
+ case E10: return TO_MUX( ADC_CHANNEL_IN14, 2 ); // Can also be ADC4
+ case E11: return TO_MUX( ADC_CHANNEL_IN15, 2 ); // Can also be ADC4
+ case E12: return TO_MUX( ADC_CHANNEL_IN16, 2 ); // Can also be ADC4
+ case E13: return TO_MUX( ADC_CHANNEL_IN3, 2 );
+ case E14: return TO_MUX( ADC_CHANNEL_IN1, 3 );
+ case F0: return TO_MUX( ADC_CHANNEL_IN10, 0 );
+ case F1: return TO_MUX( ADC_CHANNEL_IN10, 1 );
#elif defined(RP2040)
case 26U: return TO_MUX(0, 0);
case 27U: return TO_MUX(1, 0);
@@ -306,7 +395,11 @@ int16_t adc_read(adc_mux mux) {
#elif defined(RP2040)
adcConversionGroup.channel_mask = 1 << mux.input;
#else
- adcConversionGroup.sqr[0] = ADC_SQR1_SQ1_N(mux.input);
+ adcConversionGroup.sqr[0] = ADC_SQR1_SQ1_N(mux.input)
+# if ADC_DUMMY_CONVERSIONS_AT_START >= 1
+ | ADC_SQR1_SQ2_N(mux.input)
+# endif
+ ;
#endif
ADCDriver* targetDriver = intToADCDriver(mux.adc);
@@ -321,9 +414,9 @@ int16_t adc_read(adc_mux mux) {
#if defined(USE_ADCV2) || defined(RP2040)
// fake 12-bit -> N-bit scale
- return (*sampleBuffer) >> (12 - ADC_RESOLUTION);
+ return (sampleBuffer[ADC_DUMMY_CONVERSIONS_AT_START]) >> (12 - ADC_RESOLUTION);
#else
// already handled as part of adcConvert
- return *sampleBuffer;
+ return sampleBuffer[ADC_DUMMY_CONVERSIONS_AT_START];
#endif
}