[media] solo6x10: Simplify solo_enum_ext_input

Additionally, now it specifies which channels it's showing.
Signed-off-by: Ismael Luceno <ismael@iodev.co.uk>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/pci/solo6x10/solo6x10-v4l2.c

@@ -386,26 +386,24 @@ static int solo_querycap(struct file *file, void  *priv,
 static int solo_enum_ext_input(struct solo_dev *solo_dev,
 			       struct v4l2_input *input)
 {
-	static const char * const dispnames_1[] = { "4UP" };
-	static const char * const dispnames_2[] = { "4UP-1", "4UP-2" };
-	static const char * const dispnames_5[] = {
-		"4UP-1", "4UP-2", "4UP-3", "4UP-4", "16UP"
-	};
-	const char * const *dispnames;
-
-	if (input->index >= (solo_dev->nr_chans + solo_dev->nr_ext))
-		return -EINVAL;
-
-	if (solo_dev->nr_ext == 5)
-		dispnames = dispnames_5;
-	else if (solo_dev->nr_ext == 2)
-		dispnames = dispnames_2;
-	else
-		dispnames = dispnames_1;
+	int ext = input->index - solo_dev->nr_chans;
+	unsigned int nup, first;
 
-	snprintf(input->name, sizeof(input->name), "Multi %s",
-		 dispnames[input->index - solo_dev->nr_chans]);
+	if (ext >= solo_dev->nr_ext)
+		return -EINVAL;
 
+	nup   = (ext == 4) ? 16 : 4;
+	first = (ext & 3) << 2; /* first channel in the n-up */
+	snprintf(input->name, sizeof(input->name),
+		 "Multi %d-up (cameras %d-%d)",
+		 nup, first + 1, first + nup);
+	/* Possible outputs:
+	 *  Multi 4-up (cameras 1-4)
+	 *  Multi 4-up (cameras 5-8)
+	 *  Multi 4-up (cameras 9-12)
+	 *  Multi 4-up (cameras 13-16)
+	 *  Multi 16-up (cameras 1-16)
+	 */
 	return 0;
 }