[media] media: ov7670: Allow 32x maximum gain for yuv422

4x gain ceiling is not enough to capture a decent image in conditions
of total darkness and only a LED light source. Allow a maximum gain
of 32x instead.
This doesn't have any drawback since the image quality in 'normal'
light conditions is the same.

Signed-off-by: Javier Martin <javier.martin@vista-silicon.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/i2c/ov7670.c

@@ -353,7 +353,7 @@ static struct regval_list ov7670_fmt_yuv422[] = {
 	{ REG_RGB444, 0 },	/* No RGB444 please */
 	{ REG_COM1, 0 },	/* CCIR601 */
 	{ REG_COM15, COM15_R00FF },
-	{ REG_COM9, 0x18 }, /* 4x gain ceiling; 0x8 is reserved bit */
+	{ REG_COM9, 0x48 }, /* 32x gain ceiling; 0x8 is reserved bit */
 	{ 0x4f, 0x80 }, 	/* "matrix coefficient 1" */
 	{ 0x50, 0x80 }, 	/* "matrix coefficient 2" */
 	{ 0x51, 0    },		/* vb */