stm32/adc: Add support for H7 MCU series.

ADC3 is used because the H7's internal ADC channels are connected to ADC3
and the uPy driver doesn't support more than one ADC.

Only 12-bit resolution is supported because 12 is hard-coded and 14/16 bits
are not recommended on some ADC3 pins (see errata).

Values from internal ADC channels are known to give wrong values at
present.

ports/stm32/adc.c

@@ -51,7 +51,11 @@
 ///     val = adc.read_core_vref()      # read MCU VREF
 
 /* ADC defintions */
+#if defined(STM32H7)
+#define ADCx                    (ADC3)
+#else
 #define ADCx                    (ADC1)
+#endif
 #define ADCx_CLK_ENABLE         __HAL_RCC_ADC1_CLK_ENABLE
 #define ADC_NUM_CHANNELS        (19)
 
@@ -77,6 +81,15 @@
 #define ADC_CAL1                ((uint16_t*)(ADC_CAL_ADDRESS + 2))
 #define ADC_CAL2                ((uint16_t*)(ADC_CAL_ADDRESS + 4))
 
+#elif defined(STM32H7)
+
+#define ADC_FIRST_GPIO_CHANNEL  (0)
+#define ADC_LAST_GPIO_CHANNEL   (16)
+#define ADC_CAL_ADDRESS         (0x1FF1E860)
+#define ADC_CAL1                ((uint16_t*)(0x1FF1E820))
+#define ADC_CAL2                ((uint16_t*)(0x1FF1E840))
+#define ADC_CHANNEL_VBAT        ADC_CHANNEL_VBAT_DIV4
+
 #elif defined(STM32L4)
 
 #define ADC_FIRST_GPIO_CHANNEL  (1)
@@ -103,6 +116,8 @@
       defined(STM32F746xx) || defined(STM32F767xx) || \
       defined(STM32F769xx) || defined(STM32F446xx)
 #define VBAT_DIV (4)
+#elif defined(STM32H743xx)
+#define VBAT_DIV (4)
 #elif defined(STM32L475xx) || defined(STM32L476xx)
 #define VBAT_DIV (3)
 #else
@@ -143,7 +158,7 @@ STATIC bool is_adcx_channel(int channel) {
 #if defined(STM32F411xE)
     // The HAL has an incorrect IS_ADC_CHANNEL macro for the F411 so we check for temp
     return IS_ADC_CHANNEL(channel) || channel == ADC_CHANNEL_TEMPSENSOR;
-#elif defined(STM32F4) || defined(STM32F7)
+#elif defined(STM32F4) || defined(STM32F7) || defined(STM32H7)
     return IS_ADC_CHANNEL(channel);
 #elif defined(STM32L4)
     ADC_HandleTypeDef handle;
@@ -158,7 +173,7 @@ STATIC void adc_wait_for_eoc_or_timeout(int32_t timeout) {
     uint32_t tickstart = HAL_GetTick();
 #if defined(STM32F4) || defined(STM32F7)
     while ((ADCx->SR & ADC_FLAG_EOC) != ADC_FLAG_EOC) {
-#elif defined(STM32L4)
+#elif defined(STM32H7) || defined(STM32L4)
     while (READ_BIT(ADCx->ISR, ADC_FLAG_EOC) != ADC_FLAG_EOC) {
 #else
     #error Unsupported processor
@@ -172,6 +187,9 @@ STATIC void adc_wait_for_eoc_or_timeout(int32_t timeout) {
 STATIC void adcx_clock_enable(void) {
 #if defined(STM32F4) || defined(STM32F7)
     ADCx_CLK_ENABLE();
+#elif defined(STM32H7)
+    __HAL_RCC_ADC3_CLK_ENABLE();
+    __HAL_RCC_ADC_CONFIG(RCC_ADCCLKSOURCE_CLKP);
 #elif defined(STM32L4)
     __HAL_RCC_ADC_CLK_ENABLE();
 #else
@@ -187,26 +205,41 @@ STATIC void adcx_init_periph(ADC_HandleTypeDef *adch, uint32_t resolution) {
     adch->Init.ContinuousConvMode    = DISABLE;
     adch->Init.DiscontinuousConvMode = DISABLE;
     adch->Init.NbrOfDiscConversion   = 0;
-    adch->Init.DataAlign             = ADC_DATAALIGN_RIGHT;
     adch->Init.NbrOfConversion       = 1;
-    adch->Init.DMAContinuousRequests = DISABLE;
     adch->Init.EOCSelection          = ADC_EOC_SINGLE_CONV;
     adch->Init.ExternalTrigConv      = ADC_SOFTWARE_START;
     adch->Init.ExternalTrigConvEdge  = ADC_EXTERNALTRIGCONVEDGE_NONE;
     #if defined(STM32F4) || defined(STM32F7)
     adch->Init.ClockPrescaler        = ADC_CLOCK_SYNC_PCLK_DIV2;
     adch->Init.ScanConvMode          = DISABLE;
+    adch->Init.DataAlign             = ADC_DATAALIGN_RIGHT;
+    adch->Init.DMAContinuousRequests = DISABLE;
+    #elif defined(STM32H7)
+    adch->Init.ClockPrescaler        = ADC_CLOCK_SYNC_PCLK_DIV4;
+    adch->Init.BoostMode             = ENABLE;
+    adch->Init.ScanConvMode          = DISABLE;
+    adch->Init.LowPowerAutoWait      = DISABLE;
+    adch->Init.Overrun               = ADC_OVR_DATA_OVERWRITTEN;
+    adch->Init.OversamplingMode      = DISABLE;
+    adch->Init.LeftBitShift          = ADC_LEFTBITSHIFT_NONE;
+    adch->Init.ConversionDataManagement = ADC_CONVERSIONDATA_DR;
     #elif defined(STM32L4)
     adch->Init.ClockPrescaler        = ADC_CLOCK_ASYNC_DIV1;
     adch->Init.ScanConvMode          = ADC_SCAN_DISABLE;
     adch->Init.LowPowerAutoWait      = DISABLE;
     adch->Init.Overrun               = ADC_OVR_DATA_PRESERVED;
     adch->Init.OversamplingMode      = DISABLE;
+    adch->Init.DataAlign             = ADC_DATAALIGN_RIGHT;
+    adch->Init.DMAContinuousRequests = DISABLE;
     #else
     #error Unsupported processor
     #endif
 
     HAL_ADC_Init(adch);
+
+    #if defined(STM32H7)
+    HAL_ADCEx_Calibration_Start(adch, ADC_CALIB_OFFSET, ADC_SINGLE_ENDED);
+    #endif
 }
 
 STATIC void adc_init_single(pyb_obj_adc_t *adc_obj) {
@@ -221,7 +254,7 @@ STATIC void adc_init_single(pyb_obj_adc_t *adc_obj) {
       mp_hal_gpio_clock_enable(pin->gpio);
       GPIO_InitTypeDef GPIO_InitStructure;
       GPIO_InitStructure.Pin = pin->pin_mask;
-#if defined(STM32F4) || defined(STM32F7)
+#if defined(STM32F4) || defined(STM32F7) || defined(STM32H7)
       GPIO_InitStructure.Mode = GPIO_MODE_ANALOG;
 #elif defined(STM32L4)
       GPIO_InitStructure.Mode = GPIO_MODE_ANALOG_ADC_CONTROL;
@@ -251,6 +284,12 @@ STATIC void adc_config_channel(ADC_HandleTypeDef *adc_handle, uint32_t channel)
     sConfig.Rank = 1;
 #if defined(STM32F4) || defined(STM32F7)
     sConfig.SamplingTime = ADC_SAMPLETIME_15CYCLES;
+#elif defined(STM32H7)
+    sConfig.SamplingTime = ADC_SAMPLETIME_8CYCLES_5;
+    sConfig.SingleDiff = ADC_SINGLE_ENDED;
+    sConfig.OffsetNumber = ADC_OFFSET_NONE;
+    sConfig.OffsetRightShift = DISABLE;
+    sConfig.OffsetSignedSaturation = DISABLE;
 #elif defined(STM32L4)
     sConfig.SamplingTime = ADC_SAMPLETIME_12CYCLES_5;
     sConfig.SingleDiff = ADC_SINGLE_ENDED;
@@ -415,7 +454,7 @@ STATIC mp_obj_t adc_read_timed(mp_obj_t self_in, mp_obj_t buf_in, mp_obj_t freq_
             // for subsequent samples we can just set the "start sample" bit
 #if defined(STM32F4) || defined(STM32F7)
             ADCx->CR2 |= (uint32_t)ADC_CR2_SWSTART;
-#elif defined(STM32L4)
+#elif defined(STM32H7) || defined(STM32L4)
             SET_BIT(ADCx->CR, ADC_CR_ADSTART);
 #else
             #error Unsupported processor
@@ -525,7 +564,7 @@ STATIC mp_obj_t adc_read_timed_multi(mp_obj_t adc_array_in, mp_obj_t buf_array_i
             // ADC is started: set the "start sample" bit
             #if defined(STM32F4) || defined(STM32F7)
             ADCx->CR2 |= (uint32_t)ADC_CR2_SWSTART;
-            #elif defined(STM32L4)
+            #elif defined(STM32H7) || defined(STM32L4)
             SET_BIT(ADCx->CR, ADC_CR_ADSTART);
             #else
             #error Unsupported processor
@@ -580,7 +619,9 @@ typedef struct _pyb_adc_all_obj_t {
 void adc_init_all(pyb_adc_all_obj_t *adc_all, uint32_t resolution, uint32_t en_mask) {
 
     switch (resolution) {
+        #if !defined(STM32H7)
         case 6:  resolution = ADC_RESOLUTION_6B;  break;
+        #endif
         case 8:  resolution = ADC_RESOLUTION_8B;  break;
         case 10: resolution = ADC_RESOLUTION_10B; break;
         case 12: resolution = ADC_RESOLUTION_12B; break;
@@ -613,7 +654,9 @@ int adc_get_resolution(ADC_HandleTypeDef *adcHandle) {
     uint32_t res_reg = ADC_GET_RESOLUTION(adcHandle);
 
     switch (res_reg) {
+       #if !defined(STM32H7)
         case ADC_RESOLUTION_6B:  return 6;
+        #endif
         case ADC_RESOLUTION_8B:  return 8;
         case ADC_RESOLUTION_10B: return 10;
     }