sam e54: disable microcontroller.cpu.voltage

This hangs, and the usual workarounds didn't work.

Author: jepler

ports/atmel-samd/common-hal/microcontroller/Processor.c

@@ -61,6 +61,8 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <math.h>
+
 #include "py/mphal.h"
 #include "common-hal/microcontroller/Processor.h"
 
@@ -276,6 +278,9 @@ float common_hal_mcu_processor_get_temperature(void) {
 }
 
 float common_hal_mcu_processor_get_voltage(void) {
+#if MICROCONTROLLER_VOLTAGE_DISABLE
+    return NAN;
+#else
     struct adc_sync_descriptor adc;
 
     static Adc* adc_insts[] = ADC_INSTS;
@@ -320,6 +325,7 @@ float common_hal_mcu_processor_get_voltage(void) {
     adc_sync_deinit(&adc);
     // Multiply by 4 to compensate for SCALEDIOVCC division by 4.
     return (reading / 4095.0f) * 4.0f;
+#endif
 }
 
 uint32_t common_hal_mcu_processor_get_frequency(void) {

ports/atmel-samd/mpconfigport.h

@@ -75,6 +75,9 @@
 #define MICROPY_PY_SYS_PLATFORM                     "MicroChip SAMD51"
 #elif defined(SAME54)
 #define MICROPY_PY_SYS_PLATFORM                     "MicroChip SAME54"
+#ifndef MICROCONTROLLER_VOLTAGE_DISABLE
+#define MICROCONTROLLER_VOLTAGE_DISABLE (1)
+#endif
 #endif
 #define SPI_FLASH_MAX_BAUDRATE 24000000
 #define MICROPY_PY_BUILTINS_NOTIMPLEMENTED          (1)
@@ -246,4 +249,8 @@
     CIRCUITPY_COMMON_ROOT_POINTERS \
     mp_obj_t playing_audio[AUDIO_DMA_CHANNEL_COUNT];
 
+#ifndef MICROCONTROLLER_VOLTAGE_DISABLE
+#define MICROCONTROLLER_VOLTAGE_DISABLE (0)
+#endif
+
 #endif  // __INCLUDED_MPCONFIGPORT_H