V4L/DVB: saa115: add support for chroma AGC and chroma gain

Add support for chroma agc and gain to the saa7115 driver.  This allows for
users to do manual adjustment for abnormal signal conditions.

This work was sponsored by EyeMagnet Limited.
Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/saa7115.c

@@ -74,6 +74,7 @@ struct saa711x_state {
 	int contrast;
 	int hue;
 	int sat;
+	int chroma_agc;
 	int width;
 	int height;
 	u32 ident;
@@ -743,6 +744,7 @@ static int saa711x_s_clock_freq(struct v4l2_subdev *sd, u32 freq)
 static int saa711x_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
 {
 	struct saa711x_state *state = to_state(sd);
+	u8 val;
 
 	switch (ctrl->id) {
 	case V4L2_CID_BRIGHTNESS:
@@ -784,7 +786,21 @@ static int saa711x_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
 		state->hue = ctrl->value;
 		saa711x_write(sd, R_0D_CHROMA_HUE_CNTL, state->hue);
 		break;
-
+	case V4L2_CID_CHROMA_AGC:
+		val = saa711x_read(sd, R_0F_CHROMA_GAIN_CNTL);
+		state->chroma_agc = ctrl->value;
+		if (ctrl->value)
+			val &= 0x7f;
+		else
+			val |= 0x80;
+		saa711x_write(sd, R_0F_CHROMA_GAIN_CNTL, val);
+		break;
+	case V4L2_CID_CHROMA_GAIN:
+		/* Chroma gain cannot be set when AGC is enabled */
+		if (state->chroma_agc == 1)
+			return -EINVAL;
+		saa711x_write(sd, R_0F_CHROMA_GAIN_CNTL, ctrl->value | 0x80);
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -809,6 +825,12 @@ static int saa711x_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
 	case V4L2_CID_HUE:
 		ctrl->value = state->hue;
 		break;
+	case V4L2_CID_CHROMA_AGC:
+		ctrl->value = state->chroma_agc;
+		break;
+	case V4L2_CID_CHROMA_GAIN:
+		ctrl->value = saa711x_read(sd, R_0F_CHROMA_GAIN_CNTL) & 0x7f;
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -1209,6 +1231,19 @@ static int saa711x_queryctrl(struct v4l2_subdev *sd, struct v4l2_queryctrl *qc)
 		return v4l2_ctrl_query_fill(qc, 0, 127, 1, 64);
 	case V4L2_CID_HUE:
 		return v4l2_ctrl_query_fill(qc, -128, 127, 1, 0);
+	case V4L2_CID_CHROMA_AGC:
+		return v4l2_ctrl_query_fill(qc, 0, 1, 1, 1);
+	case V4L2_CID_CHROMA_GAIN:
+		qc->type = V4L2_CTRL_TYPE_INTEGER;
+		qc->flags = V4L2_CTRL_FLAG_SLIDER;
+		qc->minimum = 0;
+		qc->maximum = 127;
+		qc->step = 1;
+		qc->default_value = 0x30;
+		qc->reserved[0] = 0;
+		qc->reserved[1] = 0;
+		strlcpy(qc->name, "chroma_gain", sizeof(qc->name));
+		return 0;
 	default:
 		return -EINVAL;
 	}
@@ -1593,6 +1628,7 @@ static int saa711x_probe(struct i2c_client *client,
 	state->contrast = 64;
 	state->hue = 0;
 	state->sat = 64;
+	state->chroma_agc = 1;
 	switch (chip_id) {
 	case '1':
 		state->ident = V4L2_IDENT_SAA7111;