Switch from GPLv2 to GPLv2+

[fw/altos] / src / kernel / ao_convert_volt.c

diff --git a/src/kernel/ao_convert_volt.c b/src/kernel/ao_convert_volt.c
index 8556d423c453545bd75def9e6192e31e91dbdf70..5afedfa5bcd5c72c98af9ec0a8e4ed67cdaaa3e6 100644 (file)
--- a/src/kernel/ao_convert_volt.c
+++ b/src/kernel/ao_convert_volt.c
@@ -3,7 +3,8 @@
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -17,17 +18,23 @@
 
 #include "ao.h"
 
-#define scale(v,p,m)   ((int32_t) (v) * (AO_ADC_REFERENCE_DV * ((p) + (m))) / (AO_ADC_MAX * (m)))
+#define MUL(p,m)       ((int32_t) AO_ADC_REFERENCE_DV * ((p) + (m)))
+#define ADD(p,m)       (MUL(p,m)/2)
+#define DIV(p,m)       ((int32_t) AO_ADC_MAX * (m))
+#define scale(v,p,m)   (((int32_t) (v) * MUL(p,m) + ADD(p,m)) / DIV(p,m))
 
+#if HAS_APRS || HAS_BATTERY_REPORT
 int16_t
 ao_battery_decivolt(int16_t adc)
 {
        return scale(adc, AO_BATTERY_DIV_PLUS, AO_BATTERY_DIV_MINUS);
 }
+#endif
 
+#if HAS_APRS && defined(AO_IGNITE_DIV_PLUS)
 int16_t
 ao_ignite_decivolt(int16_t adc)
 {
        return scale(adc, AO_IGNITE_DIV_PLUS, AO_IGNITE_DIV_MINUS);
 }
-
+#endif