X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=src%2Fanalog.c;h=9bc88b310efd8aeb42333575562ce557d79c1fae;hb=77463bd397127b8a4e7266e601b4cdf87825beeb;hp=a8ca3bce650424165227546b534924081dfbef3c;hpb=cdc311957b6c1fbe68a88ed3a44fefa4a9037605;p=libsigrok.git

diff --git a/src/analog.c b/src/analog.c
index a8ca3bce..9bc88b31 100644
--- a/src/analog.c
+++ b/src/analog.c
@@ -329,6 +329,48 @@ SR_API const char *sr_analog_si_prefix(float *value, int *digits)
 	return prefixes[prefix + NEG_PREFIX_COUNT];
 }
 
+/**
+ * Check if a unit "accepts" an SI prefix.
+ *
+ * E.g. SR_UNIT_VOLT is SI prefix friendly while SR_UNIT_DECIBEL_MW or
+ * SR_UNIT_PERCENTAGE are not.
+ *
+ * @param[in] unit The unit to check for SI prefix "friendliness".
+ *
+ * @return TRUE if the unit "accept" an SI prefix.
+ *
+ * @since 0.5.0
+ */
+SR_API gboolean sr_analog_si_prefix_friendly(enum sr_unit unit)
+{
+	static const enum sr_unit prefix_friendly_units[] = {
+		SR_UNIT_VOLT,
+		SR_UNIT_AMPERE,
+		SR_UNIT_OHM,
+		SR_UNIT_FARAD,
+		SR_UNIT_KELVIN,
+		SR_UNIT_HERTZ,
+		SR_UNIT_SECOND,
+		SR_UNIT_SIEMENS,
+		SR_UNIT_VOLT_AMPERE,
+		SR_UNIT_WATT,
+		SR_UNIT_WATT_HOUR,
+		SR_UNIT_METER_SECOND,
+		SR_UNIT_HENRY,
+		SR_UNIT_GRAM
+	};
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(prefix_friendly_units); i++)
+		if (unit == prefix_friendly_units[i])
+			break;
+
+	if (unit != prefix_friendly_units[i])
+		return FALSE;
+
+	return TRUE;
+}
+
 /**
  * Convert the unit/MQ/MQ flags in the analog struct to a string.
  *