#352 First attempt to match global attributes for differential channels.

Signed-off-by: fpagliughi <[email protected]>

local.c

@@ -1465,7 +1465,7 @@ static int add_channel(struct iio_device *dev, const char *name,
 static unsigned int is_global_attr(struct iio_channel *chn, const char *attr)
 {
 	unsigned int len;
-	char *ptr;
+	char *ptr, *dashptr;
 
 	if (!chn->is_output && !strncmp(attr, "in_", 3))
 		attr += 3;
@@ -1480,6 +1480,19 @@ static unsigned int is_global_attr(struct iio_channel *chn, const char *attr)
 
 	len = ptr - attr;
 
+	// Check if matching global differential attr,
+	// like "voltage-voltage"
+	dashptr = strchr(attr, '-');
+	if (dashptr && dashptr > attr && dashptr < ptr) {
+		unsigned int len1 = dashptr - attr,
+					 len2 = ptr - dashptr - 1;
+		if (chn->id[len1] >= '0' && chn->id[len1] <= '9' &&
+			!strncmp(chn->id, attr, len1) &&
+			chn->id[len+1] >= '0' && chn->id[len+1] <= '9' &&
+			!strncmp(chn->id+len1+2, attr+len1+1, len2))
+			return 1;
+	}
+
 	if (strncmp(chn->id, attr, len))
 		return 0;