[media] gspca - sn9c20x: Change the exposure setting of Omnivision sensors

The exposure of Omnivision sensors is defined by the registers 07, 10 and 04.
This patch updates the registers 10 and 04 before using the registers 2d
and 2e (dummy lines).
Signed-off-by: Jean-François Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/gspca/sn9c20x.c

@@ -874,8 +874,8 @@ static const struct i2c_reg_u8 ov7660_init[] = {
 	   0x10, 0x61 and sd->hstart, vstart = 3, fixes ugly colored borders */
 	{0x17, 0x10}, {0x18, 0x61},
 	{0x37, 0x0f}, {0x38, 0x02}, {0x39, 0x43},
-	{0x3a, 0x00}, {0x69, 0x90}, {0x2d, 0xf6},
-	{0x2e, 0x0b}, {0x01, 0x78}, {0x02, 0x50},
+	{0x3a, 0x00}, {0x69, 0x90}, {0x2d, 0x00},
+	{0x2e, 0x00}, {0x01, 0x78}, {0x02, 0x50},
 };
 
 static const struct i2c_reg_u8 ov7670_init[] = {
@@ -1645,7 +1645,7 @@ static void set_exposure(struct gspca_dev *gspca_dev)
 	struct sd *sd = (struct sd *) gspca_dev;
 	u8 exp[8] = {sd->i2c_intf, sd->i2c_addr,
 				0x00, 0x00, 0x00, 0x00, 0x00, 0x10};
-	int expo;
+	int expo, expo2;
 
 	if (gspca_dev->streaming)
 		exp[7] = 0x1e;
@@ -1656,8 +1656,23 @@ static void set_exposure(struct gspca_dev *gspca_dev)
 	case SENSOR_OV7670:
 	case SENSOR_OV9655:
 	case SENSOR_OV9650:
+		if (expo > 547)
+			expo2 = 547;
+		else
+			expo2 = expo;
+		exp[0] |= (2 << 4);
+		exp[2] = 0x10;			/* AECH */
+		exp[3] = expo2 >> 2;
+		exp[7] = 0x10;
+		i2c_w(gspca_dev, exp);
+		exp[2] = 0x04;			/* COM1 */
+		exp[3] = expo2 & 0x0003;
+		exp[7] = 0x10;
+		i2c_w(gspca_dev, exp);
+		expo -= expo2;
+		exp[7] = 0x1e;
 		exp[0] |= (3 << 4);
-		exp[2] = 0x2d;
+		exp[2] = 0x2d;			/* ADVFL & ADVFH */
 		exp[3] = expo;
 		exp[4] = expo >> 8;
 		break;