Add ADC support STM32L4xx and STM32G4xx series MCUs (#22341)

* Update analog.c

* Changes to remove errors in compile

* Update analog.c

Fix for RP2040 build errors

* Revert "Merge branch 'adc-add-stm32l4xx-stm32g4xx' of https://github.com/Cipulot/qmk_firmware into adc-add-stm32l4xx-stm32g4xx"

This reverts commit b11c2970785ce41ec772689749d71a2bd0ab48e7, reversing
changes made to ed3051f94109b53eb1735882abfe7f57473bdca8.

* Update analog.c

Attempt fix for formatting CI error

* Update platforms/chibios/drivers/analog.c

Co-authored-by: Joel Challis <git@zvecr.com>

* Update platforms/chibios/drivers/analog.c

Co-authored-by: Joel Challis <git@zvecr.com>

* Update platforms/chibios/drivers/analog.c

Co-authored-by: Joel Challis <git@zvecr.com>

---------

Co-authored-by: Joel Challis <git@zvecr.com>

1 files changed, 102 insertions, 9 deletions

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
 }