Merge pull request #44 from a2/voltage-reference

Remove ADC_* defines in favor of hardware-specific mapping

2 files changed, 23 insertions, 22 deletions

diff --git a/watch-library/hardware/watch/watch_adc.c b/watch-library/hardware/watch/watch_adc.c
index 5ba7abdf..32f06680 100644
--- a/watch-library/hardware/watch/watch_adc.c
+++ b/watch-library/hardware/watch/watch_adc.c
@@ -23,6 +23,7 @@
  */
 
 #include "watch_adc.h"
+#include "driver_init.h"
 
 static void _watch_sync_adc(void) {
     while (ADC->SYNCBUSY.reg);
@@ -138,13 +139,30 @@ void watch_set_analog_sampling_length(uint8_t cycles) {
     _watch_sync_adc();
 }
 
+static inline uint32_t _watch_adc_get_reference_voltage(const watch_adc_reference_voltage reference) {
+    switch (reference) {
+        case ADC_REFERENCE_INTREF:
+            return ADC_REFCTRL_REFSEL_INTREF_Val;
+            break;
+        case ADC_REFERENCE_VCC_DIV1POINT6:
+            return ADC_REFCTRL_REFSEL_INTVCC0_Val;
+            break;
+        case ADC_REFERENCE_VCC_DIV2:
+            return ADC_REFCTRL_REFSEL_INTVCC1_Val;
+            break;
+        case ADC_REFERENCE_VCC:
+            return ADC_REFCTRL_REFSEL_INTVCC2_Val;
+            break;
+    }
+}
+
 void watch_set_analog_reference_voltage(watch_adc_reference_voltage reference) {
     ADC->CTRLA.bit.ENABLE = 0;
 
     if (reference == ADC_REFERENCE_INTREF) SUPC->VREF.bit.VREFOE = 1;
     else SUPC->VREF.bit.VREFOE = 0;
 
-    ADC->REFCTRL.bit.REFSEL = reference;
+    ADC->REFCTRL.bit.REFSEL = _watch_adc_get_reference_voltage(reference);
     ADC->CTRLA.bit.ENABLE = 1;
     _watch_sync_adc();
     // throw away one measurement after reference change (the channel doesn't matter).
diff --git a/watch-library/shared/watch/watch_adc.h b/watch-library/shared/watch/watch_adc.h
index d4c8586d..ea4fa9e3 100644
--- a/watch-library/shared/watch/watch_adc.h
+++ b/watch-library/shared/watch/watch_adc.h
@@ -27,23 +27,6 @@
 
 #include "watch.h"
 
-// matches adc.h
-#ifndef ADC_REFCTRL_REFSEL_INTREF_Val
-#define ADC_REFCTRL_REFSEL_INTREF_Val 0x0
-#endif
-
-#ifndef ADC_REFCTRL_REFSEL_INTVCC0_Val
-#define ADC_REFCTRL_REFSEL_INTVCC0_Val 0x1
-#endif
-
-#ifndef ADC_REFCTRL_REFSEL_INTVCC1_Val
-#define ADC_REFCTRL_REFSEL_INTVCC1_Val 0x2
-#endif
-
-#ifndef ADC_REFCTRL_REFSEL_INTVCC2_Val
-#define ADC_REFCTRL_REFSEL_INTVCC2_Val 0x5
-#endif
-
 /** @addtogroup adc Analog Input
   * @brief This section covers functions related to the SAM L22's analog-to-digital converter,
   *        as well as configuring and reading values from the five analog-capable pins on the
@@ -112,10 +95,10 @@ void watch_set_analog_num_samples(uint16_t samples);
 void watch_set_analog_sampling_length(uint8_t cycles);
 
 typedef enum {
-    ADC_REFERENCE_INTREF = ADC_REFCTRL_REFSEL_INTREF_Val,
-    ADC_REFERENCE_VCC_DIV1POINT6 = ADC_REFCTRL_REFSEL_INTVCC0_Val,
-    ADC_REFERENCE_VCC_DIV2 = ADC_REFCTRL_REFSEL_INTVCC1_Val,
-    ADC_REFERENCE_VCC = ADC_REFCTRL_REFSEL_INTVCC2_Val,
+    ADC_REFERENCE_INTREF = 0,
+    ADC_REFERENCE_VCC_DIV1POINT6,
+    ADC_REFERENCE_VCC_DIV2,
+    ADC_REFERENCE_VCC,
 } watch_adc_reference_voltage;