[media] s2250: add comment describing the hardware

Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

drivers/staging/media/go7007/s2250-board.c

@@ -29,6 +29,13 @@
 MODULE_DESCRIPTION("Sensoray 2250/2251 i2c v4l2 subdev driver");
 MODULE_LICENSE("GPL v2");
 
+/*
+ * Note: this board has two i2c devices: a vpx3226f and a tlv320aic23b.
+ * Due to the unusual way these are accessed on this device we do not
+ * reuse the i2c drivers, but instead they are implemented in this
+ * driver. It would be nice to improve on this, though.
+ */
+
 #define TLV320_ADDRESS      0x34
 #define VPX322_ADDR_ANALOGCONTROL1	0x02
 #define VPX322_ADDR_BRIGHTNESS0		0x0127