[PATCH] zr36067 driver - correct subfrequency carrier

attached patch changes the subfrequency carrier value in the adv7175
video output driver which is part of the zr36067 driver package. The
practical consequence is that the picture will be more stable on
non-passthrough video mode in NTSC. It does not affect PAL/SECAM. Patch
originally submitted by Douglas Fraser <ds-fraser@comcast.net> (8/21).
Signed-off-by: Ronald Bultje <rbultje@ronald.bitfreak.net>
Signed-off-by: Douglas Fraser <ds-fraser@comcast.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/media/video/adv7175.c

@@ -156,6 +156,22 @@ adv7175_write_block (struct i2c_client *client,
 	return ret;
 }
 
+static void
+set_subcarrier_freq (struct i2c_client *client,
+		     int                pass_through)
+{
+	/* for some reason pass_through NTSC needs
+	 * a different sub-carrier freq to remain stable. */
+	if(pass_through)
+		adv7175_write(client, 0x02, 0x00);
+	else
+		adv7175_write(client, 0x02, 0x55);
+
+	adv7175_write(client, 0x03, 0x55);
+	adv7175_write(client, 0x04, 0x55);
+	adv7175_write(client, 0x05, 0x25);
+}
+
 #ifdef ENCODER_DUMP
 static void
 dump (struct i2c_client *client)
@@ -322,6 +338,10 @@ adv7175_command (struct i2c_client *client,
 
 		case 0:
 			adv7175_write(client, 0x01, 0x00);
+
+			if (encoder->norm == VIDEO_MODE_NTSC)
+				set_subcarrier_freq(client, 1);
+
 			adv7175_write(client, 0x0c, TR1CAPT);	/* TR1 */
 			if (encoder->norm == VIDEO_MODE_SECAM)
 				adv7175_write(client, 0x0d, 0x49);	// Disable genlock
@@ -334,6 +354,10 @@ adv7175_command (struct i2c_client *client,
 
 		case 1:
 			adv7175_write(client, 0x01, 0x00);
+
+			if (encoder->norm == VIDEO_MODE_NTSC)
+				set_subcarrier_freq(client, 0);
+
 			adv7175_write(client, 0x0c, TR1PLAY);	/* TR1 */
 			adv7175_write(client, 0x0d, 0x49);
 			adv7175_write(client, 0x07, TR0MODE | TR0RST);
@@ -343,6 +367,10 @@ adv7175_command (struct i2c_client *client,
 
 		case 2:
 			adv7175_write(client, 0x01, 0x80);
+
+			if (encoder->norm == VIDEO_MODE_NTSC)
+				set_subcarrier_freq(client, 0);
+
 			adv7175_write(client, 0x0d, 0x49);
 			adv7175_write(client, 0x07, TR0MODE | TR0RST);
 			adv7175_write(client, 0x07, TR0MODE);